WorldWideScience

Sample records for adjusted skew information

  1. Metric adjusted skew information

    DEFF Research Database (Denmark)

    Hansen, Frank

    2008-01-01

    ) that vanishes for observables commuting with the state. We show that the skew information is a convex function on the manifold of states. It also satisfies other requirements, proposed by Wigner and Yanase, for an effective measure-of-information content of a state relative to a conserved observable. We...... establish a connection between the geometrical formulation of quantum statistics as proposed by Chentsov and Morozova and measures of quantum information as introduced by Wigner and Yanase and extended in this article. We show that the set of normalized Morozova-Chentsov functions describing the possible......We extend the concept of Wigner-Yanase-Dyson skew information to something we call "metric adjusted skew information" (of a state with respect to a conserved observable). This "skew information" is intended to be a non-negative quantity bounded by the variance (of an observable in a state...

  2. Metric-adjusted skew information

    DEFF Research Database (Denmark)

    Liang, Cai; Hansen, Frank

    2010-01-01

    on a bipartite system and proved superadditivity of the Wigner-Yanase-Dyson skew informations for such states. We extend this result to the general metric-adjusted skew information. We finally show that a recently introduced extension to parameter values 1 ...We give a truly elementary proof of the convexity of metric-adjusted skew information following an idea of Effros. We extend earlier results of weak forms of superadditivity to general metric-adjusted skew information. Recently, Luo and Zhang introduced the notion of semi-quantum states...... of (unbounded) metric-adjusted skew information....

  3. Inequalities for quantum skew information

    DEFF Research Database (Denmark)

    Audenaert, Koenraad; Cai, Liang; Hansen, Frank

    2008-01-01

    relation on the set of functions representing quantum Fisher information that renders the set into a lattice with an involution. This order structure generates new inequalities for the metric adjusted skew informations. In particular, the Wigner-Yanase skew information is the maximal skew information...... with respect to this order structure in the set of Wigner-Yanase-Dyson skew informations....

  4. Quantum Fisher and skew information for Unruh accelerated Dirac qubit

    International Nuclear Information System (INIS)

    Banerjee, Subhashish; Alok, Ashutosh Kumar; Omkar, S.

    2016-01-01

    We develop a Bloch vector representation of the Unruh channel for a Dirac field mode. This is used to provide a unified, analytical treatment of quantum Fisher and skew information for a qubit subjected to the Unruh channel, both in its pure form as well as in the presence of experimentally relevant external noise channels. The time evolution of Fisher and skew information is studied along with the impact of external environment parameters such as temperature and squeezing. The external noises are modelled by both purely dephasing phase damping and the squeezed generalised amplitude damping channels. An interesting interplay between the external reservoir temperature and squeezing on the Fisher and skew information is observed, in particular, for the action of the squeezed generalised amplitude damping channel. It is seen that for some regimes, squeezing can enhance the quantum information against the deteriorating influence of the ambient environment. Similar features are also observed for the analogous study of skew information, highlighting a similar origin of the Fisher and skew information. (orig.)

  5. Quantum Fisher and skew information for Unruh accelerated Dirac qubit

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Subhashish; Alok, Ashutosh Kumar [Indian Institute of Technology Jodhpur, Jodhpur (India); Omkar, S. [Indian Institute of Science Education and Research, Thiruvananthapuram (India)

    2016-08-15

    We develop a Bloch vector representation of the Unruh channel for a Dirac field mode. This is used to provide a unified, analytical treatment of quantum Fisher and skew information for a qubit subjected to the Unruh channel, both in its pure form as well as in the presence of experimentally relevant external noise channels. The time evolution of Fisher and skew information is studied along with the impact of external environment parameters such as temperature and squeezing. The external noises are modelled by both purely dephasing phase damping and the squeezed generalised amplitude damping channels. An interesting interplay between the external reservoir temperature and squeezing on the Fisher and skew information is observed, in particular, for the action of the squeezed generalised amplitude damping channel. It is seen that for some regimes, squeezing can enhance the quantum information against the deteriorating influence of the ambient environment. Similar features are also observed for the analogous study of skew information, highlighting a similar origin of the Fisher and skew information. (orig.)

  6. Shannon Entropy and Mutual Information for Multivariate Skew-Elliptical Distributions

    KAUST Repository

    Arellano-Valle, Reinaldo B.

    2012-02-27

    The entropy and mutual information index are important concepts developed by Shannon in the context of information theory. They have been widely studied in the case of the multivariate normal distribution. We first extend these tools to the full symmetric class of multivariate elliptical distributions and then to the more flexible families of multivariate skew-elliptical distributions. We study in detail the cases of the multivariate skew-normal and skew-t distributions. We implement our findings to the application of the optimal design of an ozone monitoring station network in Santiago de Chile. © 2012 Board of the Foundation of the Scandinavian Journal of Statistics.

  7. Shannon Entropy and Mutual Information for Multivariate Skew-Elliptical Distributions

    KAUST Repository

    Arellano-Valle, Reinaldo B.; Contreras-Reyes, Javier E.; Genton, Marc G.

    2012-01-01

    The entropy and mutual information index are important concepts developed by Shannon in the context of information theory. They have been widely studied in the case of the multivariate normal distribution. We first extend these tools to the full symmetric class of multivariate elliptical distributions and then to the more flexible families of multivariate skew-elliptical distributions. We study in detail the cases of the multivariate skew-normal and skew-t distributions. We implement our findings to the application of the optimal design of an ozone monitoring station network in Santiago de Chile. © 2012 Board of the Foundation of the Scandinavian Journal of Statistics.

  8. Skew information in the XY model with staggered Dzyaloshinskii-Moriya interaction

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Liang, E-mail: lqiu@cumt.edu.cn [School of Physics, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China); Quan, Dongxiao [State Key Laboratory of Integrated Services Networks, Xidian University, Xi' an, Shaanxi 710071 (China); Pan, Fei; Liu, Zhi [School of Physics, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China)

    2017-06-01

    We study the performance of the lower bound of skew information in the vicinity of transition point for the anisotropic spin-1/2 XY chain with staggered Dzyaloshinskii-Moriya interaction by use of quantum renormalization-group method. For a fixed value of the Dzyaloshinskii-Moriya interaction, there are two saturated values for the lower bound of skew information corresponding to the spin-fluid and Néel phases, respectively. The scaling exponent of the lower bound of skew information closely relates to the correlation length of the model and the Dzyaloshinskii-Moriya interaction shifts the factorization point. Our results show that the lower bound of skew information can be a good candidate to detect the critical point of XY spin chain with staggered Dzyaloshinskii-Moriya interaction.

  9. Skew quad compensation at PEP

    International Nuclear Information System (INIS)

    Murray, J.J.

    1977-10-01

    Rotational and focal effects of solenoids used in PEP detectors will cause severe perturbations of machine beam optics and must be corrected. Ordinarily this would be accomplished by the addition of compensating solenoids and adjustment of insertion quadrupole strengths. It has been found that an arbitrary cross plane coupling representing the effects of solenoids and/or skew quads in any combination can be synthesized (or compensated) exactly using a quartet of skew quads combined with other erect transport elements in a wide variety of configurations. Specific skew quad compensating systems for PEP have been designed and are under study by PEP staff. So far no fundamental flaws have been discovered. In view of that, PEP management has tentatively authorized the use of such a system in the PEP-4, PEP-9 experiments and proposes to leave the question open ''without prejudice'' for other experiments. Use of skew quad compensation involves an imponderable risk, of course, simply because the method is new and untested. But in addition to providing the only known method for dealing with skew quad perturbations, skew quad compensation, as an alternate to compensating solenoids, promises to be much cheaper, to require much less power and to occupy much less space in the IR's. The purpose of this note is to inform potential users of the foregoing situation and to explain skew quad compensation more fully. 2 refs., 1 fig., 1 tab

  10. Partial coherence with application to the monotonicity problem of coherence involving skew information

    Science.gov (United States)

    Luo, Shunlong; Sun, Yuan

    2017-08-01

    Quantifications of coherence are intensively studied in the context of completely decoherent operations (i.e., von Neuamnn measurements, or equivalently, orthonormal bases) in recent years. Here we investigate partial coherence (i.e., coherence in the context of partially decoherent operations such as Lüders measurements). A bona fide measure of partial coherence is introduced. As an application, we address the monotonicity problem of K -coherence (a quantifier for coherence in terms of Wigner-Yanase skew information) [Girolami, Phys. Rev. Lett. 113, 170401 (2014), 10.1103/PhysRevLett.113.170401], which is introduced to realize a measure of coherence as axiomatized by Baumgratz, Cramer, and Plenio [Phys. Rev. Lett. 113, 140401 (2014), 10.1103/PhysRevLett.113.140401]. Since K -coherence fails to meet the necessary requirement of monotonicity under incoherent operations, it is desirable to remedy this monotonicity problem. We show that if we modify the original measure by taking skew information with respect to the spectral decomposition of an observable, rather than the observable itself, as a measure of coherence, then the problem disappears, and the resultant coherence measure satisfies the monotonicity. Some concrete examples are discussed and related open issues are indicated.

  11. Skew Information for a Single Cooper Pair Box Interacting with a Single Cavity Field

    International Nuclear Information System (INIS)

    Metwally, N.; Al-Mannai, A.; Abdel-Aty, M.

    2013-01-01

    The dynamics of the skew information (SI) is investigated for a single Cooper Pair Box (CPB) interacting with a single cavity field. By suitably choosing the system parameters and precisely controlling the dynamics, novel connection is found between the SI and entanglement generation. It is shown that SI can be increased and reach its maximum value either by increasing the number of photons inside the cavity or considering the far off-resonant case. The number of oscillations of SI is increased by decreasing this ratio between the Josephson junction capacity and the gate capacity. This leads to significant improvement of the travelling time between the maximum and minimum values. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  12. Skew chromaticity

    International Nuclear Information System (INIS)

    Peggs, S.; Dell, G.F.

    1994-01-01

    The on-momentum description of linear coupling between horizontal and vertical betatron motion is extended to include off-momentum particles, introducing a vector quantity called the ''skew chromaticity''. This vector tends to be long in large superconducting storage rings, where it restricts the available working space in the tune plane, and modifies collective effect stability criteria. Skew chromaticity measurements at the Cornell Electron Storage Ring (CESR) and at the Fermilab Tevatron are reported, as well as tracking results from the Relativistic Heavy Ion Collider (RHIC). The observation of anomalous head-tail beam Iowa new the tune diagonal in the Tevatron are explained in terms of the extended theory, including modified criteria for headtail stability. These results are confirmed in head-tail simulations. Sources of skew chromaticity are investigated

  13. Quantum skew divergence

    Energy Technology Data Exchange (ETDEWEB)

    Audenaert, Koenraad M. R., E-mail: koenraad.audenaert@rhul.ac.uk [Department of Mathematics, Royal Holloway University of London, Egham TW20 0EX, United Kingdom and Department of Physics and Astronomy, University of Ghent, S9, Krijgslaan 281, B-9000 Ghent (Belgium)

    2014-11-15

    In this paper, we study the quantum generalisation of the skew divergence, which is a dissimilarity measure between distributions introduced by Lee in the context of natural language processing. We provide an in-depth study of the quantum skew divergence, including its relation to other state distinguishability measures. Finally, we present a number of important applications: new continuity inequalities for the quantum Jensen-Shannon divergence and the Holevo information, and a new and short proof of Bravyi's Small Incremental Mixing conjecture.

  14. Non-local correlations via Wigner-Yanase skew information in two SC-qubit having mutual interaction under phase decoherence

    Science.gov (United States)

    Mohamed, Abdel-Baset A.

    2017-10-01

    An analytical solution of the master equation that describes a superconducting cavity containing two coupled superconducting charge qubits is obtained. Quantum-mechanical correlations based on Wigner-Yanase skew information, as local quantum uncertainty and uncertainty-induced quantum non-locality, are compared to the concurrence under the effects of the phase decoherence. Local quantum uncertainty exhibits sudden changes during its time evolution and revival process. Sudden death and sudden birth occur only for entanglement, depending on the initial state of the two coupled charge qubits, while the correlations of skew information does not vanish. The quantum correlations of skew information are found to be sensitive to the dephasing rate, the photons number in the cavity, the interaction strength between the two qubits, and the qubit distribution angle of the initial state. With a proper initial state, the stationary correlation of the skew information has a non-zero stationary value for a long time interval under the phase decoherence, that it may be useful in quantum information and computation processes.

  15. The use of historical information for regional frequency analysis of extreme skew surge

    Science.gov (United States)

    Frau, Roberto; Andreewsky, Marc; Bernardara, Pietro

    2018-03-01

    The design of effective coastal protections requires an adequate estimation of the annual occurrence probability of rare events associated with a return period up to 103 years. Regional frequency analysis (RFA) has been proven to be an applicable way to estimate extreme events by sorting regional data into large and spatially distributed datasets. Nowadays, historical data are available to provide new insight on past event estimation. The utilisation of historical information would increase the precision and the reliability of regional extreme's quantile estimation. However, historical data are from significant extreme events that are not recorded by tide gauge. They usually look like isolated data and they are different from continuous data from systematic measurements of tide gauges. This makes the definition of the duration of our observations period complicated. However, the duration of the observation period is crucial for the frequency estimation of extreme occurrences. For this reason, we introduced here the concept of credible duration. The proposed RFA method (hereinafter referenced as FAB, from the name of the authors) allows the use of historical data together with systematic data, which is a result of the use of the credible duration concept.

  16. Evaluation of an adjustable epidemiologic information system.

    Directory of Open Access Journals (Sweden)

    Jiunn-Shyan Julian Wu

    Full Text Available BACKGROUND: In order to facilitate public health response and to achieve early control of infectious disease epidemics, an adjustable epidemiologic information system (AEIS was established in the Taiwan public health network in February 2006. METHODOLOGY/PRINCIPAL FINDINGS: The performance of AEIS for the period 2006 through 2008 was evaluated based on a number of response times (RT and the public health impact. After implementation of the system, the apparent overall shortened RT was mainly due to the shortening of personnel response time (PRT and the time needed to draft a new questionnaire that incurred as personnel-system interface (PSI; PRT dropped from a fluctuating range of 9.8 ∼28.8 days in the first four months to <10 days in the following months and remained low till 2008 (0.88±1.52 days. The PSIs for newly emerged infectious diseases were 2.6 and 3.4 person-hours for H5N1 in 2007 and chikungunya in 2008, respectively, a much improvement from 1142.5 person-hours for SARS in 2003. The duration of each rubella epidemic cluster was evaluated as public health impact and showed a shortening trend (p = 0.019 that concurred with the shortening of PRT from 64.8±47.3 to 25.2±38.2 hours per cluster (p<0.0001. CONCLUSIONS/SIGNIFICANCE: The first evaluation of the novel instrument AEIS that had been used to assist Taiwan's multi-level government for infectious diseases control demonstrated that it was well integrated into the existing public health infrastructure. It provided flexible tools and computer algorithms with friendly interface for timely data collection, integration, and analysis; as a result, it shortened RTs, filled in gaps of personnel lacking sufficient experiences, created a more efficient flow of response, and identified asymptomatic/mild cases early to minimize further spreading. With further development, AEIS is anticipated to be useful in the application of other acute public health events needing immediate

  17. Cross-Informant Evaluations of Preschoolers' Adjustment in Different Cultures

    Science.gov (United States)

    Israelashvili, Moshe

    2017-01-01

    An accurate and agreed upon evaluation of preschoolers' behavior is crucial for young children's positive development. This study explores possible cultural differences in cross-informants' evaluations. The premise is that informants who are from different cultures tend to give different evaluations of preschoolers' adjustment and/or that the…

  18. Mixtures of skewed Kalman filters

    KAUST Repository

    Kim, Hyoungmoon

    2014-01-01

    Normal state-space models are prevalent, but to increase the applicability of the Kalman filter, we propose mixtures of skewed, and extended skewed, Kalman filters. To do so, the closed skew-normal distribution is extended to a scale mixture class of closed skew-normal distributions. Some basic properties are derived and a class of closed skew. t distributions is obtained. Our suggested family of distributions is skewed and has heavy tails too, so it is appropriate for robust analysis. Our proposed special sequential Monte Carlo methods use a random mixture of the closed skew-normal distributions to approximate a target distribution. Hence it is possible to handle skewed and heavy tailed data simultaneously. These methods are illustrated with numerical experiments. © 2013 Elsevier Inc.

  19. Mixtures of skewed Kalman filters

    KAUST Repository

    Kim, Hyoungmoon; Ryu, Duchwan; Mallick, Bani K.; Genton, Marc G.

    2014-01-01

    Normal state-space models are prevalent, but to increase the applicability of the Kalman filter, we propose mixtures of skewed, and extended skewed, Kalman filters. To do so, the closed skew-normal distribution is extended to a scale mixture class

  20. The Zax Information Profile: a measure of college adjustment.

    Science.gov (United States)

    Sturm, D; Zax, M; Clarfield, S P; Pratt, D M

    1977-08-01

    Evaluated the effectiveness of the Zax Information Profile (ZIP), a personality test based on general fund of information, in discriminating between college students who sought mental health services and those who did not, Three successive classes of freshmen students at the Eastman School of Music of the University of Rochester were administered the ZIP. Help-seeking students were matched with non-help-seeking students for sex, age, and intellectual ability. The hypothesis that ZIP scores would differentiate between these two groups was supported by the data. The potential use of the ZIP as a predictor of college adjustment and as a useful entrance screening device was discussed.

  1. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

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

  2. WFC3/UVIS image skew

    Science.gov (United States)

    Petro, Larry

    2009-07-01

    This proposal will provide an independent check of the skew in the ACS astrometric catalog of Omega Cen stars, using exposures taken in a 45-deg range of telescope roll. The roll sequence will also provide a test for orbital variation of skew and field angle dependent PSF variations. The astrometric catalog of Omega Cen, improved for a skew, will be used to derive the geometric distorion to all UVIS filters, which has preliminarily been determined from F606W images and an astrometric catalog of 47 Tuc.

  3. Alpha - Skew Pi - Armendariz Rings

    Directory of Open Access Journals (Sweden)

    Areej M Abduldaim

    2018-03-01

    Full Text Available In this article we introduce a new concept called Alpha-skew Pi-Armendariz rings (Alpha - S Pi - ARas a generalization of the notion of Alpha-skew Armendariz rings.Another important goal behind studying this class of rings is to employ it in order to design a modern algorithm of an identification scheme according to the evolution of using modern algebra in the applications of the field of cryptography.We investigate general properties of this concept and give examples for illustration. Furthermore, this paperstudy the relationship between this concept and some previous notions related to Alpha-skew Armendariz rings. It clearly presents that every weak Alpha-skew Armendariz ring is Alpha-skew Pi-Armendariz (Alpha-S Pi-AR. Also, thisarticle showsthat the concepts of Alpha-skew Armendariz rings and Alpha-skew Pi- Armendariz rings are equivalent in case R is 2-primal and semiprime ring.Moreover, this paper proves for a semicommutative Alpha-compatible ringR that if R[x;Alpha] is nil-Armendariz, thenR is an Alpha-S Pi-AR. In addition, if R is an Alpha - S Pi -AR, 2-primal and semiprime ring, then N(R[x;Alpha]=N(R[x;Alpha]. Finally, we look forwardthat Alpha-skew Pi-Armendariz rings (Alpha-S Pi-ARbe more effect (due to their properties in the field of cryptography than Pi-Armendariz rings, weak Armendariz rings and others.For these properties and characterizations of the introduced concept Alpha-S Pi-AR, we aspire to design a novel algorithm of an identification scheme.

  4. Applying Maxi-adjustment to Adaptive Information Filtering Agents

    OpenAIRE

    Lau, Raymond; ter Hofstede, Arthur H. M.; Bruza, Peter D.

    2000-01-01

    Learning and adaptation is a fundamental property of intelligent agents. In the context of adaptive information filtering, a filtering agent's beliefs about a user's information needs have to be revised regularly with reference to the user's most current information preferences. This learning and adaptation process is essential for maintaining the agent's filtering performance. The AGM belief revision paradigm provides a rigorous foundation for modelling rational and minimal changes to an age...

  5. 77 FR 69442 - Federal Acquisition Regulation; Information Collection; Economic Price Adjustment

    Science.gov (United States)

    2012-11-19

    ...; Information Collection; Economic Price Adjustment AGENCIES: Department of Defense (DOD), General Services... economic price adjustment. Public comments are particularly invited on: Whether this collection of..., Economic Price Adjustment by any of the following methods: Regulations.gov : http://www.regulations.gov...

  6. Multivariate extended skew-t distributions and related families

    KAUST Repository

    Arellano-Valle, Reinaldo B.; Genton, Marc G.

    2010-01-01

    A class of multivariate extended skew-t (EST) distributions is introduced and studied in detail, along with closely related families such as the subclass of extended skew-normal distributions. Besides mathematical tractability and modeling flexibility in terms of both skewness and heavier tails than the normal distribution, the most relevant properties of the EST distribution include closure under conditioning and ability to model lighter tails as well. The first part of the present paper examines probabilistic properties of the EST distribution, such as various stochastic representations, marginal and conditional distributions, linear transformations, moments and in particular Mardia’s measures of multivariate skewness and kurtosis. The second part of the paper studies statistical properties of the EST distribution, such as likelihood inference, behavior of the profile log-likelihood, the score vector and the Fisher information matrix. Especially, unlike the extended skew-normal distribution, the Fisher information matrix of the univariate EST distribution is shown to be non-singular when the skewness is set to zero. Finally, a numerical application of the conditional EST distribution is presented in the context of confidential data perturbation.

  7. Multivariate extended skew-t distributions and related families

    KAUST Repository

    Arellano-Valle, Reinaldo B.

    2010-12-01

    A class of multivariate extended skew-t (EST) distributions is introduced and studied in detail, along with closely related families such as the subclass of extended skew-normal distributions. Besides mathematical tractability and modeling flexibility in terms of both skewness and heavier tails than the normal distribution, the most relevant properties of the EST distribution include closure under conditioning and ability to model lighter tails as well. The first part of the present paper examines probabilistic properties of the EST distribution, such as various stochastic representations, marginal and conditional distributions, linear transformations, moments and in particular Mardia’s measures of multivariate skewness and kurtosis. The second part of the paper studies statistical properties of the EST distribution, such as likelihood inference, behavior of the profile log-likelihood, the score vector and the Fisher information matrix. Especially, unlike the extended skew-normal distribution, the Fisher information matrix of the univariate EST distribution is shown to be non-singular when the skewness is set to zero. Finally, a numerical application of the conditional EST distribution is presented in the context of confidential data perturbation.

  8. Kinematic correction for roller skewing

    Science.gov (United States)

    Savage, M.; Loewenthal, S. H.

    1980-01-01

    A theory of kinematic stabilization of rolling cylinders is developed for high-speed cylindrical roller bearings. This stabilization requires race and roller crowning to product changes in the rolling geometry as the roller shifts axially. These changes put a reverse skew in the rolling elements by changing the rolling taper. Twelve basic possible bearing modifications are identified in this paper. Four have single transverse convex curvature in the rollers while eight have rollers with compound transverse curvature composed of a central cylindrical band of constant radius surrounded by symmetric bands with both slope and transverse curvature.

  9. Skew chromaticity in large accelerators

    International Nuclear Information System (INIS)

    Peggs, S.; Dell, G.F.

    1995-01-01

    The 2-D ''skew chromaticity'' vector k is introduced when the standard on-momentum description of linear coupling is extended to include off-momentum particles. A lattice that is well decoupled on-momentum may be badly decoupled off-momentum, inside the natural momentum spread of the beam. There are two general areas of concern: (1) the free space in the tune plane is decreased; (2) collective phenomena may be destabilized. Two strong new criteria for head-tail stability in the presence of off-momentum coupling are derived, which are consistent with experimental and operational observations at the Tevatron, and with tracking data from RHIC

  10. Network Skewness Measures Resilience in Lake Ecosystems

    Science.gov (United States)

    Langdon, P. G.; Wang, R.; Dearing, J.; Zhang, E.; Doncaster, P.; Yang, X.; Yang, H.; Dong, X.; Hu, Z.; Xu, M.; Yanjie, Z.; Shen, J.

    2017-12-01

    Changes in ecosystem resilience defy straightforward quantification from biodiversity metrics, which ignore influences of community structure. Naturally self-organized network structures show positive skewness in the distribution of node connections. Here we test for skewness reduction in lake diatom communities facing anthropogenic stressors, across a network of 273 lakes in China containing 452 diatom species. Species connections show positively skewed distributions in little-impacted lakes, switching to negative skewness in lakes associated with human settlement, surrounding land-use change, and higher phosphorus concentration. Dated sediment cores reveal a down-shifting of network skewness as human impacts intensify, and reversal with recovery from disturbance. The appearance and degree of negative skew presents a new diagnostic for quantifying system resilience and impacts from exogenous forcing on ecosystem communities.

  11. Measuring Profitability Impacts of Information Technology: Use of Risk Adjusted Measures.

    Science.gov (United States)

    Singh, Anil; Harmon, Glynn

    2003-01-01

    Focuses on understanding how investments in information technology are reflected in the income statements and balance sheets of firms. Shows that the relationship between information technology investments and corporate profitability is much better explained by using risk-adjusted measures of corporate profitability than using the same measures…

  12. Cooperation in a dynamical adjustment of duopoly game with incomplete information

    International Nuclear Information System (INIS)

    Ding Zhanwen; Shi Guiping

    2009-01-01

    In the output competition of Cournot game, the adjustment of output is considered under the circumstances that participants have incomplete information. In this paper, two strategies with output's adjustment are mainly discussed: the tit-for-tat strategy and the tit-for-tat strategy with cooperative intention and their dynamic systems, respectively. The result shows that the tit-for-tat strategy may lead to the cooperation of them, but the stability of adjustment system is sensitive to the parameters; while the tit-for-tat strategy with cooperative intention can make the Pareto Optimality stable within the parameters' certain scope.

  13. Objective Bayesian Analysis of Skew- t Distributions

    KAUST Repository

    BRANCO, MARCIA D'ELIA; GENTON, MARC G.; LISEO, BRUNERO

    2012-01-01

    We study the Jeffreys prior and its properties for the shape parameter of univariate skew-t distributions with linear and nonlinear Student's t skewing functions. In both cases, we show that the resulting priors for the shape parameter are symmetric

  14. A skewed distribution with asset pricing applications

    NARCIS (Netherlands)

    de Roon, Frans; Karehnke, P.

    2017-01-01

    Recent research has identified skewness and downside risk as one of the most important features of risk. We present a new distribution which makes modeling skewed risks no more difficult than normally distributed (symmetric) risks. Our distribution is a combination of the “downside” and “upside”

  15. Skew-adjacency matrices of graphs

    NARCIS (Netherlands)

    Cavers, M.; Cioaba, S.M.; Fallat, S.; Gregory, D.A.; Haemers, W.H.; Kirkland, S.J.; McDonald, J.J.; Tsatsomeros, M.

    2012-01-01

    The spectra of the skew-adjacency matrices of a graph are considered as a possible way to distinguish adjacency cospectral graphs. This leads to the following topics: graphs whose skew-adjacency matrices are all cospectral; relations between the matchings polynomial of a graph and the characteristic

  16. Portfolio optimization with skewness and kurtosis

    Science.gov (United States)

    Lam, Weng Hoe; Jaaman, Saiful Hafizah Hj.; Isa, Zaidi

    2013-04-01

    Mean and variance of return distributions are two important parameters of the mean-variance model in portfolio optimization. However, the mean-variance model will become inadequate if the returns of assets are not normally distributed. Therefore, higher moments such as skewness and kurtosis cannot be ignored. Risk averse investors prefer portfolios with high skewness and low kurtosis so that the probability of getting negative rates of return will be reduced. The objective of this study is to compare the portfolio compositions as well as performances between the mean-variance model and mean-variance-skewness-kurtosis model by using the polynomial goal programming approach. The results show that the incorporation of skewness and kurtosis will change the optimal portfolio compositions. The mean-variance-skewness-kurtosis model outperforms the mean-variance model because the mean-variance-skewness-kurtosis model takes skewness and kurtosis into consideration. Therefore, the mean-variance-skewness-kurtosis model is more appropriate for the investors of Malaysia in portfolio optimization.

  17. Skewed factor models using selection mechanisms

    KAUST Repository

    Kim, Hyoung-Moon

    2015-12-21

    Traditional factor models explicitly or implicitly assume that the factors follow a multivariate normal distribution; that is, only moments up to order two are involved. However, it may happen in real data problems that the first two moments cannot explain the factors. Based on this motivation, here we devise three new skewed factor models, the skew-normal, the skew-tt, and the generalized skew-normal factor models depending on a selection mechanism on the factors. The ECME algorithms are adopted to estimate related parameters for statistical inference. Monte Carlo simulations validate our new models and we demonstrate the need for skewed factor models using the classic open/closed book exam scores dataset.

  18. Skewed factor models using selection mechanisms

    KAUST Repository

    Kim, Hyoung-Moon; Maadooliat, Mehdi; Arellano-Valle, Reinaldo B.; Genton, Marc G.

    2015-01-01

    Traditional factor models explicitly or implicitly assume that the factors follow a multivariate normal distribution; that is, only moments up to order two are involved. However, it may happen in real data problems that the first two moments cannot explain the factors. Based on this motivation, here we devise three new skewed factor models, the skew-normal, the skew-tt, and the generalized skew-normal factor models depending on a selection mechanism on the factors. The ECME algorithms are adopted to estimate related parameters for statistical inference. Monte Carlo simulations validate our new models and we demonstrate the need for skewed factor models using the classic open/closed book exam scores dataset.

  19. Children's Representations of Family Relationships, Peer Information Processing, and School Adjustment

    Science.gov (United States)

    Bascoe, Sonnette M.; Davies, Patrick T.; Sturge-Apple, Melissa L.; Cummings, E. Mark

    2009-01-01

    This study examined children's peer information processing as an explanatory mechanism underlying the association between their insecure representations of interparental and parent-child relationships and school adjustment in a sample of 210 first graders. Consistent with emotional security theory (P. T. Davies & E. M. Cummings, 1994), results…

  20. 78 FR 52781 - 30-Day Notice of Proposed Information Collection: Disclosure of Adjustable Rate Mortgages (ARMs...

    Science.gov (United States)

    2013-08-26

    ... INFORMATION CONTACT: Colette Pollard, Reports Management Officer, QDAM, Department of Housing and Urban... telephone 202-402-3400. Persons with hearing or speech impairments may access this number through TTY by... the mortgagor, at the time of loan application, a written explanation of the features of an adjustable...

  1. Skewness of the standard model possible implications

    International Nuclear Information System (INIS)

    Nielsen, H.B.; Brene, N.

    1989-09-01

    In this paper we consider combinations of gauge algebra and set of rules for quantization of gauge charges. We show that the combination of the algebra of the standard model and the rule satisfied by the electric charges of the quarks and leptons has an exceptional high degree of a kind of asymmetry which we call skewness. Assuming that skewness has physical significance and adding two other rather plausible assumptions, we may conclude that space time must have a non simply connected topology on very small distances. Such topology would allow a kind of symmetry breakdown leading to a more skew combination of gauge algebra and set of quantization rules. (orig.)

  2. Flow induced by a skewed vortex cylinder

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre

    2017-01-01

    The velocity field induced by a skewed vortex cylinder of longitudinal and tangential vorticity is derived in this chapter by direct integration of the Biot– Savart law. The derivation steps are provided in details. The results of Castles and Durham for the skewed semi-infinite cylinder....... The content of this chapter is based on the publication of the author entitled "Cylindrical vortex wake model: skewed cylinder, application to yawed or tilted rotors" [1]. Results from this chapter are applied: in Chap. 21 to model a wind turbine (or rotor) in yaw, in Chap. 22 to derive a new yaw...

  3. SKEW QUADRUPOLE FOCUSING LATTICES AND APPLICATIONS

    International Nuclear Information System (INIS)

    Parker, B.

    2001-01-01

    In this paper we revisit using skew quadrupole fields in place of traditional normal upright quadrupole fields to make beam focusing structures. We illustrate by example skew lattice decoupling, dispersion suppression and chromatic correction using the neutrino factory Study-II muon storage ring design. Ongoing BNL investigation of flat coil magnet structures that allow building a very compact muon storage ring arc and other flat coil configurations that might bring significant magnet cost reduction to a VLHC motivate our study of skew focusing

  4. Uncovering the skewness news impact curve

    Czech Academy of Sciences Publication Activity Database

    Anatolyev, Stanislav; Petukhov, A.

    2016-01-01

    Roč. 14, č. 4 (2016), s. 746-771 ISSN 1479-8409 Institutional support: RVO:67985998 Keywords : conditional skewness * news impact curve * stock returns Subject RIV: AH - Economics Impact factor: 1.800, year: 2016

  5. Uncovering the skewness news impact curve

    Czech Academy of Sciences Publication Activity Database

    Anatolyev, Stanislav; Petukhov, A.

    2016-01-01

    Roč. 14, č. 4 (2016), s. 746-771 ISSN 1479-8409 Institutional support: PRVOUK-P23 Keywords : conditional skewness * news impact curve * stock returns Subject RIV: AH - Economics Impact factor: 1.800, year: 2016

  6. Hybrid excited claw pole generator with skewed and non-skewed permanent magnets

    Science.gov (United States)

    Wardach, Marcin

    2017-12-01

    This article contains simulation results of the Hybrid Excited Claw Pole Generator with skewed and non-skewed permanent magnets on rotor. The experimental machine has claw poles on two rotor sections, between which an excitation control coil is located. The novelty of this machine is existence of non-skewed permanent magnets on claws of one part of the rotor and skewed permanent magnets on the second one. The paper presents the construction of the machine and analysis of the influence of the PM skewing on the cogging torque and back-emf. Simulation studies enabled the determination of the cogging torque and the back-emf rms for both: the strengthening and the weakening of magnetic field. The influence of the magnets skewing on the cogging torque and the back-emf rms have also been analyzed.

  7. Hybrid excited claw pole generator with skewed and non-skewed permanent magnets

    Directory of Open Access Journals (Sweden)

    Wardach Marcin

    2017-12-01

    Full Text Available This article contains simulation results of the Hybrid Excited Claw Pole Generator with skewed and non-skewed permanent magnets on rotor. The experimental machine has claw poles on two rotor sections, between which an excitation control coil is located. The novelty of this machine is existence of non-skewed permanent magnets on claws of one part of the rotor and skewed permanent magnets on the second one. The paper presents the construction of the machine and analysis of the influence of the PM skewing on the cogging torque and back-emf. Simulation studies enabled the determination of the cogging torque and the back-emf rms for both: the strengthening and the weakening of magnetic field. The influence of the magnets skewing on the cogging torque and the back-emf rms have also been analyzed.

  8. A novel technique for estimation of skew in binary text document ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Gatos et al (1997) have proposed a new skew detection method based on the information ..... different books, magazines and journals. ..... Duda R O, Hart P E 1973 Pattern classification and scene analysis (New York: Wiley-Interscience).

  9. Adjusting Estimates of the Expected Value of Information for Implementation: Theoretical Framework and Practical Application.

    Science.gov (United States)

    Andronis, Lazaros; Barton, Pelham M

    2016-04-01

    Value of information (VoI) calculations give the expected benefits of decision making under perfect information (EVPI) or sample information (EVSI), typically on the premise that any treatment recommendations made in light of this information will be implemented instantly and fully. This assumption is unlikely to hold in health care; evidence shows that obtaining further information typically leads to "improved" rather than "perfect" implementation. To present a method of calculating the expected value of further research that accounts for the reality of improved implementation. This work extends an existing conceptual framework by introducing additional states of the world regarding information (sample information, in addition to current and perfect information) and implementation (improved implementation, in addition to current and optimal implementation). The extension allows calculating the "implementation-adjusted" EVSI (IA-EVSI), a measure that accounts for different degrees of implementation. Calculations of implementation-adjusted estimates are illustrated under different scenarios through a stylized case study in non-small cell lung cancer. In the particular case study, the population values for EVSI and IA-EVSI were £ 25 million and £ 8 million, respectively; thus, a decision assuming perfect implementation would have overestimated the expected value of research by about £ 17 million. IA-EVSI was driven by the assumed time horizon and, importantly, the specified rate of change in implementation: the higher the rate, the greater the IA-EVSI and the lower the difference between IA-EVSI and EVSI. Traditionally calculated measures of population VoI rely on unrealistic assumptions about implementation. This article provides a simple framework that accounts for improved, rather than perfect, implementation and offers more realistic estimates of the expected value of research. © The Author(s) 2015.

  10. Profiles of dyadic adjustment for advanced prostate cancer to inform couple-based intervention.

    Science.gov (United States)

    Elliott, Kate-Ellen J; Scott, Jennifer L; Monsour, Michael; Nuwayhid, Fadi

    2015-01-01

    The purpose of the study is to describe from a relational perspective, partners' psychological adjustment, coping and support needs for advanced prostate cancer. A mixed methods design was adopted, employing triangulation of qualitative and quantitative data, to produce dyadic profiles of adjustment for six couples recruited from the urology clinics of local hospitals in Tasmania, Australia. Dyads completed a video-taped communication task, semi-structured interview and standardised self-report questionnaires. Themes identified were associated with the dyadic challenges of the disease experience (e.g. relationship intimacy, disease progression and carer burden). Couples with poor psychological adjustment profiles had both clinical and global locus of distress, treatment side-effects, carer burden and poor general health. Resilient couples demonstrated relationship closeness and adaptive cognitive and behavioural coping strategies. The themes informed the adaption of an effective program for couples coping with women's cancers (CanCOPE, to create a program for couples facing advanced prostate cancer (ProCOPE-Adv). Mixed method results inform the development of psychological therapy components for couples coping with advanced prostate cancer. The concomitance of co-morbid health problems may have implications for access and engagement for older adult populations in face-to-face intervention.

  11. Adjusting Expected Mortality Rates Using Information From a Control Population: An Example Using Socioeconomic Status.

    Science.gov (United States)

    Bower, Hannah; Andersson, Therese M-L; Crowther, Michael J; Dickman, Paul W; Lambe, Mats; Lambert, Paul C

    2018-04-01

    Expected or reference mortality rates are commonly used in the calculation of measures such as relative survival in population-based cancer survival studies and standardized mortality ratios. These expected rates are usually presented according to age, sex, and calendar year. In certain situations, stratification of expected rates by other factors is required to avoid potential bias if interest lies in quantifying measures according to such factors as, for example, socioeconomic status. If data are not available on a population level, information from a control population could be used to adjust expected rates. We have presented two approaches for adjusting expected mortality rates using information from a control population: a Poisson generalized linear model and a flexible parametric survival model. We used a control group from BCBaSe-a register-based, matched breast cancer cohort in Sweden with diagnoses between 1992 and 2012-to illustrate the two methods using socioeconomic status as a risk factor of interest. Results showed that Poisson and flexible parametric survival approaches estimate similar adjusted mortality rates according to socioeconomic status. Additional uncertainty involved in the methods to estimate stratified, expected mortality rates described in this study can be accounted for using a parametric bootstrap, but this might make little difference if using a large control population.

  12. Generalized parton distribution for non zero skewness

    International Nuclear Information System (INIS)

    Kumar, Narinder; Dahiya, Harleen; Teryaev, Oleg

    2012-01-01

    In the theory of strong interactions the main open question is how the nucleon and other hadrons are built from quarks and gluons, the fundamental degrees of freedom in QCD. An essential tool to investigate hadron structure is the study of deep inelastic scattering processes, where individual quarks and gluons can be resolved. The parton densities extracted from such processes encode the distribution of longitudinal momentum and polarization carried by quarks, antiquarks and gluons within a fast moving hadron. They have provided much to shape the physical picture of hadron structure. In the recent years, it has become clear that appropriate exclusive scattering processes may provide such information encoded in the general parton distributions (GPDs). Here, we investigate the GPD for deep virtual compton scattering (DVCS) for the non zero skewness. The study has investigated the GPDs by expressing them in terms of overlaps of light front wave functions (LFWFs). The work represented a spin 1/2 system as a composite of spin 1/2 fermion and spin 1 boson with arbitrary masses

  13. Feature-selective Attention in Frontoparietal Cortex: Multivoxel Codes Adjust to Prioritize Task-relevant Information.

    Science.gov (United States)

    Jackson, Jade; Rich, Anina N; Williams, Mark A; Woolgar, Alexandra

    2017-02-01

    Human cognition is characterized by astounding flexibility, enabling us to select appropriate information according to the objectives of our current task. A circuit of frontal and parietal brain regions, often referred to as the frontoparietal attention network or multiple-demand (MD) regions, are believed to play a fundamental role in this flexibility. There is evidence that these regions dynamically adjust their responses to selectively process information that is currently relevant for behavior, as proposed by the "adaptive coding hypothesis" [Duncan, J. An adaptive coding model of neural function in prefrontal cortex. Nature Reviews Neuroscience, 2, 820-829, 2001]. Could this provide a neural mechanism for feature-selective attention, the process by which we preferentially process one feature of a stimulus over another? We used multivariate pattern analysis of fMRI data during a perceptually challenging categorization task to investigate whether the representation of visual object features in the MD regions flexibly adjusts according to task relevance. Participants were trained to categorize visually similar novel objects along two orthogonal stimulus dimensions (length/orientation) and performed short alternating blocks in which only one of these dimensions was relevant. We found that multivoxel patterns of activation in the MD regions encoded the task-relevant distinctions more strongly than the task-irrelevant distinctions: The MD regions discriminated between stimuli of different lengths when length was relevant and between the same objects according to orientation when orientation was relevant. The data suggest a flexible neural system that adjusts its representation of visual objects to preferentially encode stimulus features that are currently relevant for behavior, providing a neural mechanism for feature-selective attention.

  14. Skewed X-inactivation in cloned mice

    International Nuclear Information System (INIS)

    Senda, Sho; Wakayama, Teruhiko; Yamazaki, Yukiko; Ohgane, Jun; Hattori, Naka; Tanaka, Satoshi; Yanagimachi, Ryuzo; Shiota, Kunio

    2004-01-01

    In female mammals, dosage compensation for X-linked genes is accomplished by inactivation of one of two X chromosomes. The X-inactivation ratio (a percentage of the cells with inactivated maternal X chromosomes in the whole cells) is skewed as a consequence of various genetic mutations, and has been observed in a number of X-linked disorders. We previously reported that phenotypically normal full-term cloned mouse fetuses had loci with inappropriate DNA methylation. Thus, cloned mice are excellent models to study abnormal epigenetic events in mammalian development. In the present study, we analyzed X-inactivation ratios in adult female cloned mice (B6C3F1). Kidneys of eight naturally produced controls and 11 cloned mice were analyzed. Although variations in X-inactivation ratio among the mice were observed in both groups, the distributions were significantly different (Ansary-Bradley test, P < 0.01). In particular, 2 of 11 cloned mice showed skewed X-inactivation ratios (19.2% and 86.8%). Similarly, in intestine, 1 of 10 cloned mice had a skewed ratio (75.7%). Skewed X-inactivation was observed to various degrees in different tissues of different individuals, suggesting that skewed X-inactivation in cloned mice is the result of secondary cell selection in combination with stochastic distortion of primary choice. The present study is the first demonstration that skewed X-inactivation occurs in cloned animals. This finding is important for understanding both nuclear transfer technology and etiology of X-linked disorders

  15. Quantifying the cross-sectional relationship between online sentiment and the skewness of stock returns

    Science.gov (United States)

    Shen, Dehua; Liu, Lanbiao; Zhang, Yongjie

    2018-01-01

    The constantly increasing utilization of social media as the alternative information channel, e.g., Twitter, provides us a unique opportunity to investigate the dynamics of the financial market. In this paper, we employ the daily happiness sentiment extracted from Twitter as the proxy for the online sentiment dynamics and investigate its association with the skewness of stock returns of 26 international stock market index returns. The empirical results show that: (1) by dividing the daily happiness sentiment into quintiles from the least to the most happiness days, the skewness of the Most-happiness subgroup is significantly larger than that of the Least-happiness subgroup. Besides, there exist significant differences in any pair of subgroups; (2) in an event study methodology, we further show that the skewness around the highest happiness days is significantly larger than the skewness around the lowest happiness days.

  16. Objective Bayesian Analysis of Skew- t Distributions

    KAUST Repository

    BRANCO, MARCIA D'ELIA

    2012-02-27

    We study the Jeffreys prior and its properties for the shape parameter of univariate skew-t distributions with linear and nonlinear Student\\'s t skewing functions. In both cases, we show that the resulting priors for the shape parameter are symmetric around zero and proper. Moreover, we propose a Student\\'s t approximation of the Jeffreys prior that makes an objective Bayesian analysis easy to perform. We carry out a Monte Carlo simulation study that demonstrates an overall better behaviour of the maximum a posteriori estimator compared with the maximum likelihood estimator. We also compare the frequentist coverage of the credible intervals based on the Jeffreys prior and its approximation and show that they are similar. We further discuss location-scale models under scale mixtures of skew-normal distributions and show some conditions for the existence of the posterior distribution and its moments. Finally, we present three numerical examples to illustrate the implications of our results on inference for skew-t distributions. © 2012 Board of the Foundation of the Scandinavian Journal of Statistics.

  17. Skew-signings of positive weighted digraphs

    Directory of Open Access Journals (Sweden)

    Kawtar Attas

    2018-07-01

    Full Text Available An arc-weighted digraph is a pair (D , ω where D is a digraph and ω is an arc-weight function that assigns to each arc u v of D a nonzero real number ω (u v . Given an arc-weighted digraph (D , ω with vertices v 1 , … , v n , the weighted adjacency matrix of (D , ω is defined as the n × n matrix A (D , ω = [ a i j ] where a i j = ω ( v i v j if v i v j is an arc of D , and 0 otherwise. Let (D , ω be a positive arc-weighted digraph and assume that D is loopless and symmetric. A skew-signing of (D , ω is an arc-weight function ω ′ such that ω ′ (u v = ± ω (u v and ω ′ (u v ω ′ (v u < 0 for every arc u v of D . In this paper, we give necessary and sufficient conditions under which the characteristic polynomial of A (D , ω ′ is the same for all skew-signings ω ′ of (D , ω . Our main theorem generalizes a result of Cavers et al. (2012 about skew-adjacency matrices of graphs. Keywords: Arc-weighted digraphs, Skew-signing of a digraph, Weighted adjacency matrix, Mathematics Subject Classification: 05C22, 05C31, 05C50

  18. Risk Aversion and Skewness Preference: a comment

    NARCIS (Netherlands)

    G.T. Post (Thierry); P. van Vliet (Pim)

    2003-01-01

    textabstractEmpirically, co-skewness of asset returns seems to explain a substantial part of the cross-sectional variation of mean return not explained by beta. Thisfinding is typically interpreted in terms of a risk averse representativeinvestor with a cubic utility function. This comment questions

  19. Investors’ Risk Preference Characteristics and Conditional Skewness

    Directory of Open Access Journals (Sweden)

    Fenghua Wen

    2014-01-01

    Full Text Available Perspective on behavioral finance, we take a new look at the characteristics of investors’ risk preference, building the D-GARCH-M model, DR-GARCH-M model, and GARCHC-M model to investigate their changes with states of gain and loss and values of return together with other time-varying characteristics of investors’ risk preference. Based on a full description of risk preference characteristic, we develop a GARCHCS-M model to study its effect on the return skewness. The top ten market value stock composite indexes from Global Stock Exchange in 2012 are adopted to make the empirical analysis. The results show that investors are risk aversion when they gain and risk seeking when they lose, which effectively explains the inconsistent risk-return relationship. Moreover, the degree of risk aversion rises with the increasing gain and that of risk seeking improves with the increasing losses. Meanwhile, we find that investors’ inherent risk preference in most countries displays risk seeking, and their current risk preference is influenced by last period’s risk preference and disturbances. At last, investors’ risk preferences affect the conditional skewness; specifically, their risk aversion makes return skewness reduce, while risk seeking makes the skewness increase.

  20. Steel framing strategies for highly skewed bridges to reduce/eliminate distortion near skewed supports.

    Science.gov (United States)

    2014-05-01

    Different problems in straight skewed steel I-girder bridges are often associated with the methods used for detailing the cross-frames. Use of theoretical terms to describe these detailing methods and absence of complete and simplified design approac...

  1. 77 FR 38650 - Agency Information Collection Activities: Refugee/Asylee Adjusting Status, OMB Control Number...

    Science.gov (United States)

    2012-06-28

    ... Collection Activities: Refugee/Asylee Adjusting Status, OMB Control Number 1615-0070; Extension, Without...: Form I- 643, Health and Human Services Statistical Data for Refugee/Asylee Adjusting Status; OMB... currently approved collection. (2) Title of the Form/Collection: Refugee/Asylee Adjusting Status. (3) Agency...

  2. α-Skew π-McCoy Rings

    Directory of Open Access Journals (Sweden)

    Areej M. Abduldaim

    2013-01-01

    Full Text Available As a generalization of α-skew McCoy rings, we introduce the concept of α-skew π-McCoy rings, and we study the relationships with another two new generalizations, α-skew π1-McCoy rings and α-skew π2-McCoy rings, observing the relations with α-skew McCoy rings, π-McCoy rings, α-skew Armendariz rings, π-regular rings, and other kinds of rings. Also, we investigate conditions such that α-skew π1-McCoy rings imply α-skew π-McCoy rings and α-skew π2-McCoy rings. We show that in the case where R is a nonreduced ring, if R is 2-primal, then R is an α-skew π-McCoy ring. And, let R be a weak (α,δ-compatible ring; if R is an α-skew π1-McCoy ring, then R is α-skew π2-McCoy.

  3. Matrix orderings and their associated skew fields

    International Nuclear Information System (INIS)

    Mahdavi-Hezavehi, M.

    1990-08-01

    Matrix orderings on rings are investigated. It is shown that in the commutative case they are essentially positive cones. This is proved by reducing it to the field case; similarly one can show that on a skew field, matrix positive cones can be reduced to positive cones by using the Dieudonne determinant. Our main result shows that there is a natural bijection between the matrix positive cones on a ring R and the ordered epic R-fields. (author). 7 refs

  4. Analysis of Parasite and Other Skewed Counts

    Science.gov (United States)

    Alexander, Neal

    2012-01-01

    Objective To review methods for the statistical analysis of parasite and other skewed count data. Methods Statistical methods for skewed count data are described and compared, with reference to those used over a ten year period of Tropical Medicine and International Health. Two parasitological datasets are used for illustration. Results Ninety papers were identified, 89 with descriptive and 60 with inferential analysis. A lack of clarity is noted in identifying measures of location, in particular the Williams and geometric mean. The different measures are compared, emphasizing the legitimacy of the arithmetic mean for skewed data. In the published papers, the t test and related methods were often used on untransformed data, which is likely to be invalid. Several approaches to inferential analysis are described, emphasizing 1) non-parametric methods, while noting that they are not simply comparisons of medians, and 2) generalized linear modelling, in particular with the negative binomial distribution. Additional methods, such as the bootstrap, with potential for greater use are described. Conclusions Clarity is recommended when describing transformations and measures of location. It is suggested that non-parametric methods and generalized linear models are likely to be sufficient for most analyses. PMID:22943299

  5. 76 FR 72242 - Proposed Information Collection (Survey of Post-Deployment Adjustment Among OEF and OIF Veterans...

    Science.gov (United States)

    2011-11-22

    ... collection of information on respondents, including through the use of automated collection techniques or the use of other forms of information technology. Title: Survey of Post-Deployment Adjustment Among OEF... female Veterans who experienced war zone stressor beyond traditional combat and sexual trauma during...

  6. An Evaluation of the Adjusted DeLone and McLean Model of Information Systems Success; the case of financial information system in Ferdowsi University of Mashhad

    OpenAIRE

    Mohammad Lagzian; Shamsoddin Nazemi; Fatemeh Dadmand

    2012-01-01

    Assessing the success of information systems within organizations has been identified as one of the most critical subjects of information system management in both public and private organizations. It is therefore important to measure the success of information systems from the user's perspective. The purpose of the current study was to evaluate the degree of information system success by the adjusted DeLone and McLean’s model in the field financial information system (FIS) in an Iranian Univ...

  7. Inferring climate variability from skewed proxy records

    Science.gov (United States)

    Emile-Geay, J.; Tingley, M.

    2013-12-01

    Many paleoclimate analyses assume a linear relationship between the proxy and the target climate variable, and that both the climate quantity and the errors follow normal distributions. An ever-increasing number of proxy records, however, are better modeled using distributions that are heavy-tailed, skewed, or otherwise non-normal, on account of the proxies reflecting non-normally distributed climate variables, or having non-linear relationships with a normally distributed climate variable. The analysis of such proxies requires a different set of tools, and this work serves as a cautionary tale on the danger of making conclusions about the underlying climate from applications of classic statistical procedures to heavily skewed proxy records. Inspired by runoff proxies, we consider an idealized proxy characterized by a nonlinear, thresholded relationship with climate, and describe three approaches to using such a record to infer past climate: (i) applying standard methods commonly used in the paleoclimate literature, without considering the non-linearities inherent to the proxy record; (ii) applying a power transform prior to using these standard methods; (iii) constructing a Bayesian model to invert the mechanistic relationship between the climate and the proxy. We find that neglecting the skewness in the proxy leads to erroneous conclusions and often exaggerates changes in climate variability between different time intervals. In contrast, an explicit treatment of the skewness, using either power transforms or a Bayesian inversion of the mechanistic model for the proxy, yields significantly better estimates of past climate variations. We apply these insights in two paleoclimate settings: (1) a classical sedimentary record from Laguna Pallcacocha, Ecuador (Moy et al., 2002). Our results agree with the qualitative aspects of previous analyses of this record, but quantitative departures are evident and hold implications for how such records are interpreted, and

  8. Skew quad compensation for SPEAR minibeta optics

    International Nuclear Information System (INIS)

    Wille, K.

    1984-06-01

    With the new minibeta insertion for SPEAR the betatron coupling and the perturbations of beam optics caused by the solenoid field of the MARK III detector can't be compensated by the simple coils used so far. Therefore another scheme with four skew quads arranged in two families has been chosen. Even though this scheme doesn't compensate the effect of the solenoid on the beam completely, the residual emittance coupling is much less than 1% which should be sufficient under all running conditions. The major advantage of this concept is its simplicity

  9. Leverage and Deepening Business Cycle Skewness

    DEFF Research Database (Denmark)

    Jensen, Henrik; Petrella, Ivan; Ravn, Søren Hove

    2017-01-01

    We document that the U.S. economy has been characterized by an increasingly negative business cycle asymmetry over the last three decades. This finding can be explained by the concurrent increase in the financial leverage of households and firms. To support this view, we devise and estimate......, booms become progressively smoother and more prolonged than busts. We are therefore able to reconcile a more negatively skewed business cycle with the Great Moderation in cyclical volatility. Finally, in line with recent empirical evidence, financially-driven expansions lead to deeper contractions...

  10. Health-based risk adjustment: is inpatient and outpatient diagnostic information sufficient?

    Science.gov (United States)

    Lamers, L M

    Adequate risk adjustment is critical to the success of market-oriented health care reforms in many countries. Currently used risk adjusters based on demographic and diagnostic cost groups (DCGs) do not reflect expected costs accurately. This study examines the simultaneous predictive accuracy of inpatient and outpatient morbidity measures and prior costs. DCGs, pharmacy cost groups (PCGs), and prior year's costs improve the predictive accuracy of the demographic model substantially. DCGs and PCGs seem complementary in their ability to predict future costs. However, this study shows that the combination of DCGs and PCGs still leaves room for cream skimming.

  11. [Do laymen understand information about hospital quality? An empirical verification using risk-adjusted mortality rates as an example].

    Science.gov (United States)

    Sander, Uwe; Kolb, Benjamin; Taheri, Fatemeh; Patzelt, Christiane; Emmert, Martin

    2017-11-01

    The effect of public reporting to improve quality in healthcare is reduced by the limited intelligibility of information about the quality of healthcare providers. This may result in worse health-related choices especially for older people and those with lower levels of education. There is, as yet, little information as to whether laymen understand the concepts behind quality comparisons and if this comprehension is correlated with hospital choices. An instrument with 20 items was developed to analyze the intelligibility of five technical terms which were used in German hospital report cards to explain risk-adjusted death rates. Two online presentations of risk-adjusted death rates for five hospitals in the style of hospital report cards were developed. An online survey of 353 volunteers tested the comprehension of the risk-adjusted mortality rates and included an experimental hospital choice. The intelligibility of five technical terms was tested: risk-adjusted, actual and expected death rate, reference range and national average. The percentages of correct answers for the five technical terms were in the range of 75.0-60.2%. Between 23.8% and 5.1% of the respondents were not able to answer the question about the technical term itself. The least comprehensible technical terms were "risk-adjusted death rate" and "reference range". The intelligibility of the 20 items that were used to test the comprehension of the risk-adjusted mortality was between 89.5% and 14.2%. The two items that proved to be least comprehensible were related to the technical terms "risk-adjusted death rate" and "reference range". For all five technical terms it was found that a better comprehension correlated significantly with better hospital choices. We found a better than average intelligibility for the technical terms "actual and expected death rate" and for "national average". The least understandable were "risk-adjusted death rate" and "reference range". Since the self

  12. 77 FR 64119 - Agency Information Collection Activities: Refugee/Asylee Adjusting Status, Form Number I-643...

    Science.gov (United States)

    2012-10-18

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Citizenship and Immigration Services [OMB Control Number 1615... of Homeland Security (DHS), U.S. Citizenship and Immigration Services (USCIS) will be submitting the... for adjustment of status, with the U.S. Citizenship and Immigration Services (USCIS). USCIS will...

  13. Does Realized Skewness Predict the Cross-Section of Equity Returns?

    DEFF Research Database (Denmark)

    Amaya, Diego; Christoffersen, Peter; Jacobs, Kris

    We use intraday data to compute weekly realized variance, skewness, and kurtosis for equity returns and study the realized moments’ time-series and cross-sectional properties. We investigate if this week’'s realized moments are informative for the cross-section of next week'’s stock returns. We...

  14. Strategy of image-information-guided dose rate adjustment in digital X-ray television

    International Nuclear Information System (INIS)

    Sliva, K.

    1992-01-01

    The experiments were so designed and carried out that it was even possible for extremely overexposed or underexposed displays to be ascertained within the framework of this study. They were based on observations in phantoms suitable to simulate situations encountered in actual practice. These permitted variations in patient volume (using different water volumes) just as well as the creation of any desired organ constellation (by insertion of bone material, etc.). It is one requirement of this experimental procedure that the X-ray unit used can be operated without automatic dose rate adjustment. A computer equipped with Frame-Grabber card may serve as an image memory. (orig.) [de

  15. The underpricing of Brazilian IPOs and the adjustment to public and private information

    Directory of Open Access Journals (Sweden)

    Ricardo R.G. Avelino

    2013-03-01

    Full Text Available This paper examines the underwriters' treatment of information throughout the IPO pricing process based on a sample of Brazilian companies that went public between 2004 and 2011. There is evidence that the offer price partially incorporates the information contained into the Bovespa index during the book-building period, reacting symmetrically to upward and downward movements. The first-day return, as a result, is predictable on the basis of this information. Positive private information disclosed during the book-building period is also partially incorporated into the offer price. Issues priced above the midpoint of the initial price range are associated with higher initial returns.

  16. Random skew plane partitions with a piecewise periodic back wall

    DEFF Research Database (Denmark)

    Boutillier, Cedric; Mkrtchyan, Sevak; Reshetikhin, Nicolai

    Random skew plane partitions of large size distributed according to an appropriately scaled Schur process develop limit shapes. In the present work we consider the limit of large random skew plane partitions where the inner boundary approaches a piecewise linear curve with non-lattice slopes. Muc...

  17. Learning a Novel Pattern through Balanced and Skewed Input

    Science.gov (United States)

    McDonough, Kim; Trofimovich, Pavel

    2013-01-01

    This study compared the effectiveness of balanced and skewed input at facilitating the acquisition of the transitive construction in Esperanto, characterized by the accusative suffix "-n" and variable word order (SVO, OVS). Thai university students (N = 98) listened to 24 sentences under skewed (one noun with high token frequency) or…

  18. Selection on skewed characters and the paradox of stasis.

    Science.gov (United States)

    Bonamour, Suzanne; Teplitsky, Céline; Charmantier, Anne; Crochet, Pierre-André; Chevin, Luis-Miguel

    2017-11-01

    Observed phenotypic responses to selection in the wild often differ from predictions based on measurements of selection and genetic variance. An overlooked hypothesis to explain this paradox of stasis is that a skewed phenotypic distribution affects natural selection and evolution. We show through mathematical modeling that, when a trait selected for an optimum phenotype has a skewed distribution, directional selection is detected even at evolutionary equilibrium, where it causes no change in the mean phenotype. When environmental effects are skewed, Lande and Arnold's (1983) directional gradient is in the direction opposite to the skew. In contrast, skewed breeding values can displace the mean phenotype from the optimum, causing directional selection in the direction of the skew. These effects can be partitioned out using alternative selection estimates based on average derivatives of individual relative fitness, or additive genetic covariances between relative fitness and trait (Robertson-Price identity). We assess the validity of these predictions using simulations of selection estimation under moderate sample sizes. Ecologically relevant traits may commonly have skewed distributions, as we here exemplify with avian laying date - repeatedly described as more evolutionarily stable than expected - so this skewness should be accounted for when investigating evolutionary dynamics in the wild. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  19. Characteristic functions of scale mixtures of multivariate skew-normal distributions

    KAUST Repository

    Kim, Hyoung-Moon

    2011-08-01

    We obtain the characteristic function of scale mixtures of skew-normal distributions both in the univariate and multivariate cases. The derivation uses the simple stochastic relationship between skew-normal distributions and scale mixtures of skew-normal distributions. In particular, we describe the characteristic function of skew-normal, skew-t, and other related distributions. © 2011 Elsevier Inc.

  20. An Evaluation of the Adjusted DeLone and McLean Model of Information Systems Success; the case of financial information system in Ferdowsi University of Mashhad

    Directory of Open Access Journals (Sweden)

    Mohammad Lagzian

    2012-07-01

    Full Text Available Assessing the success of information systems within organizations has been identified as one of the most critical subjects of information system management in both public and private organizations. It is therefore important to measure the success of information systems from the user's perspective. The purpose of the current study was to evaluate the degree of information system success by the adjusted DeLone and McLean’s model in the field financial information system (FIS in an Iranian University. The relationships among the dimensions in an extended systems success measurement framework were tested. Data were collected by questionnaire from end-users of a financial information system at Ferdowsi University of Mashhad. The adjusted DeLone and McLean model was contained five variables (system quality, information quality, system use, user satisfaction, and individual impact. The results revealed that system quality was significant predictor of system use, user satisfaction and individual impact. Information quality was also a significant predictor of user satisfaction and individual impact, but not of system use. System use and user satisfaction were positively related to individual impact. The influence of user satisfaction on system use was insignificant

  1. Investigating the Investigative Task: Testing for Skewness--An Investigation of Different Test Statistics and Their Power to Detect Skewness

    Science.gov (United States)

    Tabor, Josh

    2010-01-01

    On the 2009 AP[c] Statistics Exam, students were asked to create a statistic to measure skewness in a distribution. This paper explores several of the most popular student responses and evaluates which statistic performs best when sampling from various skewed populations. (Contains 8 figures, 3 tables, and 4 footnotes.)

  2. Nilradicals of skew Hurwitz series of rings

    Directory of Open Access Journals (Sweden)

    Morteza Ahmadi

    2015-05-01

    Full Text Available ‎For a ring endomorphism α of a ring R, ‎Krempa called α a rigid endomorphism if aα(a=0 implies a = 0 for a in R. ‎A ring R is called rigid if there exists a rigid endomorphism of R. ‎In this paper‎, ‎we extend the α-rigid property of a ring R to the upper nilradical N_r(R of R. ‎For an endomorphism α and the upper nilradical N_r(R of a ring R, ‎we introduce the condition (*: ‎N_r(R is a α-ideal of R and aα(a in N_r(R implies a in N_r(R for a in R. ‎We study characterizations of a ring R with an endomorphism α satisfying the condition (*, ‎and we investigate their related properties‎. ‎The connections between the upper nilradical of R and the upper nilradical of the skew Hurwitz series ring (HR,α of R are also investigated‎.

  3. Real quartic surfaces containing 16 skew lines

    Directory of Open Access Journals (Sweden)

    Isidro Nieto

    2004-01-01

    Full Text Available It is well known that there is an open three-dimensional subvariety Ms of the Grassmannian of lines in ℙ3 which parametrizes smooth irreducible complex surfaces of degree 4 which are Heisenberg invariant, and each quartic contains 32 lines but only 16 skew lines, being determined by its configuration of lines, are called a double 16. We consider here the problem of visualizing in a computer the real Heisenberg invariant quartic surface and the real double 16. We construct a family of points l∈Ms parametrized by a two-dimensional semialgebraic variety such that under a change of coordinates of l into its Plüecker, coordinates transform into the real coordinates for a line L in ℙ3, which is then used to construct a program in Maple 7. The program allows us to draw the quartic surface and the set of transversal lines to L. Additionally, we include a table of a group of examples. For each test example we specify a parameter, the viewing angle of the image, compilation time, and other visual properties of the real surface and its real double 16. We include at the end of the paper an example showing the surface containing the double 16.

  4. 76 FR 39128 - Comment Request for Information Collection for the Trade Adjustment Assistance Community College...

    Science.gov (United States)

    2011-07-05

    ... individuals that receive services and find employment through these grants. The accuracy, reliability, and... of a standard set of data elements, definitions, and specifications at all levels of the workforce... proposed collection of information, including the validity of the methodology and assumptions used; Enhance...

  5. Characteristic functions of scale mixtures of multivariate skew-normal distributions

    KAUST Repository

    Kim, Hyoung-Moon; Genton, Marc G.

    2011-01-01

    We obtain the characteristic function of scale mixtures of skew-normal distributions both in the univariate and multivariate cases. The derivation uses the simple stochastic relationship between skew-normal distributions and scale mixtures of skew

  6. Continuity diaphragm for skewed continuous span precast prestressed concrete girder bridges.

    Science.gov (United States)

    2004-10-01

    Continuity diaphragms used on skewed bents in prestressed girder bridges cause difficulties in detailing and : construction. Details for bridges with large diaphragm skew angles (>30) have not been a problem for LA DOTD. : However, as the skew angl...

  7. The underpricing of Brazilian IPOs and the adjustment to public and private information

    Directory of Open Access Journals (Sweden)

    Ricardo R.G. Avelino

    2013-03-01

    Full Text Available This paper examines the underwriters' treatment of information throughout the IPO pricing process based on a sample of Brazilian companies that went public between 2004 and 2011. There is evidence that the offer price partially incorporates the information contained into the Bovespa index during the book-building period, reacting symmetrically to upward and downward movements. The first-day return, as a result, is predictable on the basis of this information. Positive private information disclosed during the book-building period is also partially incorporated into the offer price. Issues priced above the midpoint of the initial price range are associated with higher initial returns.Este artigo examina o tratamento da informação pelo coordenador líder durante o processo de apreçamento do IPO baseado em uma amostra de firmas brasileiras que abriram o capital entre 2004 e2011. O preço de oferta incorpora parcialmente a informação contida no Ibovespa durante o período de book-building, reagindo simetricamente a movimentos de alta e baixa. O retorno inicial, como resultado, pode ser previsto com base nesta informação. Informação privada positiva revelada durante o período de book-building também é parcialmente incorporada no preço de oferta. Ofertas com preço acima do ponto médio do intervalo inicialmente estabelecido produzem maiores retornos iniciais.

  8. Regularized multivariate regression models with skew-t error distributions

    KAUST Repository

    Chen, Lianfu; Pourahmadi, Mohsen; Maadooliat, Mehdi

    2014-01-01

    We consider regularization of the parameters in multivariate linear regression models with the errors having a multivariate skew-t distribution. An iterative penalized likelihood procedure is proposed for constructing sparse estimators of both

  9. International portfolio diversification, skewness and the role of gold

    OpenAIRE

    LUCEY, BRIAN MICHAEL

    2007-01-01

    PUBLISHED The paper examines the optimal allocation of assets in well diversified equity based portfolio where the investor is concerned not only with mean and variance but also with the skewness of the returns.

  10. Systems of Differential Equations with Skew-Symmetric, Orthogonal Matrices

    Science.gov (United States)

    Glaister, P.

    2008-01-01

    The solution of a system of linear, inhomogeneous differential equations is discussed. The particular class considered is where the coefficient matrix is skew-symmetric and orthogonal, and where the forcing terms are sinusoidal. More general matrices are also considered.

  11. PRINCIPLE OF SKEW QUADRUPOLE MODULATION TO MEASURE BETATRON COUPLING

    International Nuclear Information System (INIS)

    LUO, Y.; PILAT, F.; ROSER, T.

    2004-01-01

    The measurement of the residual betatron coupling via skew quadrupole modulation is a new diagnostics technique that has been developed and tested at the Relativistic Heavy Ion Collider (RHIC) as a very promising method for the linear decoupling on the ramp. By modulating the strengths of different skew quadrupole families the two eigentunes are precisely measured with the phase lock loop system. The projections of the residual coupling coefficient onto the skew quadrupole coupling modulation directions are determined. The residual linear coupling could be corrected according to the measurement. An analytical solution for skew quadrupole modulation based on Hamiltonian perturbation approximation is given, and simulation code using smooth accelerator model is also developed. Some issues concerning the practical applications of this technique are discussed

  12. Scale and shape mixtures of multivariate skew-normal distributions

    KAUST Repository

    Arellano-Valle, Reinaldo B.; Ferreira, Clé cio S.; Genton, Marc G.

    2018-01-01

    We introduce a broad and flexible class of multivariate distributions obtained by both scale and shape mixtures of multivariate skew-normal distributions. We present the probabilistic properties of this family of distributions in detail and lay down

  13. Delivering Left-Skewed Portfolio Payoff Distributions in the Presence of Transaction Costs

    Directory of Open Access Journals (Sweden)

    Jacek B Krawczyk

    2015-08-01

    Full Text Available For pension-savers, a low payoff is a financial disaster. Such investors will most likely prefer left-skewed payoff distributions over right-skewed payoff distributions. We explore how such distributions can be delivered. Cautious-relaxed utility measures are cautious in ensuring that payoffs don’t fall much below a reference value, but relaxed about exceeding it. We find that the payoff distribution delivered by a cautious-relaxed utility measure has appealing features which payoff distributions delivered by traditional utility functions don’t. In particular, cautious-relaxed distributions can have the mass concentrated on the left, hence be left-skewed. However, cautious-relaxed strategies prescribe frequent portfolio adjustments which may be expensive if transaction costs are charged. In contrast, more traditional strategies can be time-invariant. Thus we investigate the impact of transaction costs on the appeal of cautious-relaxed strategies. We find that relatively high transaction fees are required for the cautious-relaxed strategy to lose its appeal. This paper contributes to the literature which compares utility measures by the payoff distributions they produce and finds that a cautious-relaxed utility measure will deliver payoffs that many investors will prefer.

  14. Experimental Robot Model Adjustments Based on Force–Torque Sensor Information

    Directory of Open Access Journals (Sweden)

    Santiago Martinez

    2018-03-01

    Full Text Available The computational complexity of humanoid robot balance control is reduced through the application of simplified kinematics and dynamics models. However, these simplifications lead to the introduction of errors that add to other inherent electro-mechanic inaccuracies and affect the robotic system. Linear control systems deal with these inaccuracies if they operate around a specific working point but are less precise if they do not. This work presents a model improvement based on the Linear Inverted Pendulum Model (LIPM to be applied in a non-linear control system. The aim is to minimize the control error and reduce robot oscillations for multiple working points. The new model, named the Dynamic LIPM (DLIPM, is used to plan the robot behavior with respect to changes in the balance status denoted by the zero moment point (ZMP. Thanks to the use of information from force–torque sensors, an experimental procedure has been applied to characterize the inaccuracies and introduce them into the new model. The experiments consist of balance perturbations similar to those of push-recovery trials, in which step-shaped ZMP variations are produced. The results show that the responses of the robot with respect to balance perturbations are more precise and the mechanical oscillations are reduced without comprising robot dynamics.

  15. A note on generalized skew derivations on Lie ideals

    Indian Academy of Sciences (India)

    MOHAMMAD ASHRAF

    2018-04-24

    Apr 24, 2018 ... Abstract. Let R be a prime ring, Z(R) its center, C its extended centroid, L a Lie ideal of R, F a generalized skew derivation associated with a skew derivation d and automorphism α. Assume that there exist t ≥ 1 and m, n ≥ 0 fixed integers such that vu = umF(uv)tun for all u,v ∈ L. Then it is shown that either ...

  16. Asympotic efficiency of signed - rank symmetry tests under skew alternatives.

    OpenAIRE

    Alessandra Durio; Yakov Nikitin

    2002-01-01

    The efficiency of some known tests for symmetry such as the sign test, the Wilcoxon signed-rank test or more general linear signed rank tests was studied mainly under the classical alternatives of location. However it is interesting to compare the efficiencies of these tests under asymmetric alternatives like the so-called skew alternative proposed in Azzalini (1985). We find and compare local Bahadur efficiencies of linear signed-rank statistics for skew alternatives and discuss also the con...

  17. Flow in Rotating Serpentine Coolant Passages With Skewed Trip Strips

    Science.gov (United States)

    Tse, David G.N.; Steuber, Gary

    1996-01-01

    Laser velocimetry was utilized to map the velocity field in serpentine turbine blade cooling passages with skewed trip strips. The measurements were obtained at Reynolds and Rotation numbers of 25,000 and 0.24 to assess the influence of trips, passage curvature and Coriolis force on the flow field. The interaction of the secondary flows induced by skewed trips with the passage rotation produces a swirling vortex and a corner recirculation zone. With trips skewed at +45 deg, the secondary flows remain unaltered as the cross-flow proceeds from the passage to the turn. However, the flow characteristics at these locations differ when trips are skewed at -45 deg. Changes in the flow structure are expected to augment heat transfer, in agreement with the heat transfer measurements of Johnson, et al. The present results show that trips are skewed at -45 deg in the outward flow passage and trips are skewed at +45 deg in the inward flow passage maximize heat transfer. Details of the present measurements were related to the heat transfer measurements of Johnson, et al. to relate fluid flow and heat transfer measurements.

  18. Magnetic measurements of the correction and adjustment magnets of the main ring

    International Nuclear Information System (INIS)

    Trbojevic, D.

    1986-07-01

    Correction magnets correct the field imperfections and alignment errors of the main quadrupole and bend magnets. For reducing and controlling chromaticity there are 186 sextupoles and 78 octupoles, while for suppressing various resonances there are 12 normal and 18 skew sextupoles and 24 normal and 19 skew quadrupoles. Beam positions are individually controlled by 108 horizontal and 108 skew dipoles. This report includes results of the all Main Ring correction and adjustment magnet harmonic measurements. The measurement principle and basic equations are described

  19. Natural frequencies and an atlas of mode shapes for generally-laminated, thick, skew, trapezoidal plates

    OpenAIRE

    Lovejoy, Andrew Elwyn

    1994-01-01

    Composite materials are increasingly finding use in structures, such as aircraft components, and thus, an accurate method of predicting response is required. Even laminated structures that are considered thin can be significantly affected by transverse shear effects, and as a result, transverse shear should not be neglected. The free vibration response of generally-laminated, thick, skew, trapezoidal plates is investigated as there appears to be a lack of information in this ar...

  20. Statistics on cannabis users skew perceptions of cannabis use

    Directory of Open Access Journals (Sweden)

    Rachel Melissa Burns

    2013-11-01

    Full Text Available Collecting information about the prevalence of cannabis use is necessary but not sufficient for understanding the size, dynamics, and outcomes associated with cannabis markets. This paper uses two data sets describing cannabis consumption in the United States and Europe to highlight 1 differences in inferences about sub-populations based on the measure used to quantify cannabis-related activity; 2 how different measures of cannabis-related activity can be used to more accurately describe trends in cannabis usage over time; and 3 the correlation between frequency of use in the past month and average grams consumed per day. Key findings: Focusing on days of use instead of prevalence shows substantially greater increases in U.S. cannabis use in recent years; however, the recent increase is mostly among adults, not youth. Relatively more rapid growth in use days also occurred among the college-educated and Hispanic. Further, data from a survey conducted in several European countries show a strong positive correlation between frequency of use and quantity consumed per day of use, suggesting consumption is even more skewed toward the minority of heavy users than is suggested by days-of-use calculations.

  1. Skew Projection of Echo-Detected EPR Spectra for Increased Sensitivity and Resolution

    Science.gov (United States)

    Bowman, Michael K.; Krzyaniak, Matthew D.; Cruce, Alex A.; Weber, Ralph T.

    2013-01-01

    The measurement of EPR spectra during pulsed EPR experiments is commonly accomplished by recording the integral of the electron spin echo as the applied magnetic field is stepped through the spectrum. This approach to echo-detected EPR spectral measurement (ED-EPR) limits sensitivity and spectral resolution and can cause gross distortions in the resulting spectra because some of the information present in the electron spin echo is discarded in such measurements. However, Fourier Transformation of echo shapes measured at a series of magnetic field values followed by skew projection onto either a magnetic field or resonance frequency axis can increase both spectral resolution and sensitivity without the need to trade one against the other. Examples of skew-projected spectra with single crystals, glasses and powders show resolution improvements as large as a factor of seven with sensitivity increases of as much as a factor of five. PMID:23644351

  2. Isomorphic Operators and Functional Equations for the Skew-Circulant Algebra

    Directory of Open Access Journals (Sweden)

    Zhaolin Jiang

    2014-01-01

    Full Text Available The skew-circulant matrix has been used in solving ordinary differential equations. We prove that the set of skew-circulants with complex entries has an idempotent basis. On that basis, a skew-cyclic group of automorphisms and functional equations on the skew-circulant algebra is introduced. And different operators on linear vector space that are isomorphic to the algebra of n×n complex skew-circulant matrices are displayed in this paper.

  3. Uniqueness: skews bit occurrence frequencies in randomly generated fingerprint libraries.

    Science.gov (United States)

    Chen, Nelson G

    2016-08-01

    Requiring that randomly generated chemical fingerprint libraries have unique fingerprints such that no two fingerprints are identical causes a systematic skew in bit occurrence frequencies, the proportion at which specified bits are set. Observed frequencies (O) at which each bit is set within the resulting libraries systematically differ from frequencies at which bits are set at fingerprint generation (E). Observed frequencies systematically skew toward 0.5, with the effect being more pronounced as library size approaches the compound space, which is the total number of unique possible fingerprints given the number of bit positions each fingerprint contains. The effect is quantified for varying library sizes as a fraction of the overall compound space, and for changes in the specified frequency E. The cause and implications for this systematic skew are subsequently discussed. When generating random libraries of chemical fingerprints, the imposition of a uniqueness requirement should either be avoided or taken into account.

  4. A Finite Segment Method for Skewed Box Girder Analysis

    Directory of Open Access Journals (Sweden)

    Xingwei Xue

    2018-01-01

    Full Text Available A finite segment method is presented to analyze the mechanical behavior of skewed box girders. By modeling the top and bottom plates of the segments with skew plate beam element under an inclined coordinate system and the webs with normal plate beam element, a spatial elastic displacement model for skewed box girder is constructed, which can satisfy the compatibility condition at the corners of the cross section for box girders. The formulation of the finite segment is developed based on the variational principle. The major advantage of the proposed approach, in comparison with the finite element method, is that it can simplify a three-dimensional structure into a one-dimensional structure for structural analysis, which results in significant saving in computational times. At last, the accuracy and efficiency of the proposed finite segment method are verified by a model test.

  5. Performance Analyses of IDEAL Algorithm on Highly Skewed Grid System

    Directory of Open Access Journals (Sweden)

    Dongliang Sun

    2014-03-01

    Full Text Available IDEAL is an efficient segregated algorithm for the fluid flow and heat transfer problems. This algorithm has now been extended to the 3D nonorthogonal curvilinear coordinates. Highly skewed grids in the nonorthogonal curvilinear coordinates can decrease the convergence rate and deteriorate the calculating stability. In this study, the feasibility of the IDEAL algorithm on highly skewed grid system is analyzed by investigating the lid-driven flow in the inclined cavity. It can be concluded that the IDEAL algorithm is more robust and more efficient than the traditional SIMPLER algorithm, especially for the highly skewed and fine grid system. For example, at θ = 5° and grid number = 70 × 70 × 70, the convergence rate of the IDEAL algorithm is 6.3 times faster than that of the SIMPLER algorithm, and the IDEAL algorithm can converge almost at any time step multiple.

  6. The skew ray ambiguity in the analysis of videokeratoscopic data.

    Science.gov (United States)

    Iskander, D Robert; Davis, Brett A; Collins, Michael J

    2007-05-01

    Skew ray ambiguity is present in most videokeratoscopic measurements when azimuthal components of the corneal curvature are not taken into account. There have been some reported studies based on theoretical predictions and measured test surfaces suggesting that skew ray ambiguity is significant for highly deformed corneas or decentered corneal measurements. However, the effect of skew ray ambiguity in ray tracing through videokeratoscopic data has not been studied in depth. We have evaluated the significance of the skew ray ambiguity and its effect on the analyzed corneal optics. This has been achieved by devising a procedure in which we compared the corneal wavefront aberrations estimated from 3D ray tracing with those determined from 2D (meridional based) estimates of the refractive power. The latter was possible due to recently developed concept of refractive Zernike power polynomials which links the refractive power domain with that of the wavefront. Simulated corneal surfaces as well as data from a range of corneas (from two different Placido disk-based videokeratoscopes) were used to find the limit at which the difference in estimated corneal wavefronts (or the corresponding refractive powers) would have clinical significance (e.g., equivalent to 0.125 D or more). The inclusion/exclusion of the skew ray in the analyses showed some differences in the results. However, the proposed procedure showed clinically significant differences only for highly deformed corneas and only for large corneal diameters. For the overwhelming majority of surfaces, the skew ray ambiguity is not a clinically significant issue in the analysis of the videokeratoscopic data indicating that the meridional processing such as that encountered in calculation of the refractive power maps is adequate.

  7. Skew-orthogonal polynomials, differential systems and random matrix theory

    International Nuclear Information System (INIS)

    Ghosh, S.

    2007-01-01

    We study skew-orthogonal polynomials with respect to the weight function exp[-2V (x)], with V (x) = Σ K=1 2d (u K /K)x K , u 2d > 0, d > 0. A finite subsequence of such skew-orthogonal polynomials arising in the study of Orthogonal and Symplectic ensembles of random matrices, satisfy a system of differential-difference-deformation equation. The vectors formed by such subsequence has the rank equal to the degree of the potential in the quaternion sense. These solutions satisfy certain compatibility condition and hence admit a simultaneous fundamental system of solutions. (author)

  8. Market skewness risk and the cross section of stock returns

    DEFF Research Database (Denmark)

    Chang, B.Y.; Christoffersen, Peter; Jacobs, K.

    2013-01-01

    The cross section of stock returns has substantial exposure to risk captured by higher moments of market returns. We estimate these moments from daily Standard & Poor's 500 index option data. The resulting time series of factors are genuinely conditional and forward-looking. Stocks with high...... exposure to innovations in implied market skewness exhibit low returns on average. The results are robust to various permutations of the empirical setup. The market skewness risk premium is statistically and economically significant and cannot be explained by other common risk factors such as the market...... excess return or the size, book-to-market, momentum, and market volatility factors, or by firm characteristics....

  9. The Skew Risk Premium in the Equity Index Market

    OpenAIRE

    Roman Kozhan; Anthony Neuberger; Paul Schneider

    2013-01-01

    We develop a new method for measuring moment risk premiums. We find that the skew premium accounts for over 40% of the slope in the implied volatility curve in the S&P 500 market. Skew risk is tightly related to variance risk, in the sense that strategies designed to capture the one and hedge out exposure to the other earn an insignificant risk premium. This provides a new testable restriction for asset pricing models trying to capture, in particular, disaster risk premiums. We base our resul...

  10. Partially linear mixed-effects joint models for skewed and missing longitudinal competing risks outcomes.

    Science.gov (United States)

    Lu, Tao; Lu, Minggen; Wang, Min; Zhang, Jun; Dong, Guang-Hui; Xu, Yong

    2017-12-18

    Longitudinal competing risks data frequently arise in clinical studies. Skewness and missingness are commonly observed for these data in practice. However, most joint models do not account for these data features. In this article, we propose partially linear mixed-effects joint models to analyze skew longitudinal competing risks data with missingness. In particular, to account for skewness, we replace the commonly assumed symmetric distributions by asymmetric distribution for model errors. To deal with missingness, we employ an informative missing data model. The joint models that couple the partially linear mixed-effects model for the longitudinal process, the cause-specific proportional hazard model for competing risks process and missing data process are developed. To estimate the parameters in the joint models, we propose a fully Bayesian approach based on the joint likelihood. To illustrate the proposed model and method, we implement them to an AIDS clinical study. Some interesting findings are reported. We also conduct simulation studies to validate the proposed method.

  11. Analysis of financial time series using multiscale entropy based on skewness and kurtosis

    Science.gov (United States)

    Xu, Meng; Shang, Pengjian

    2018-01-01

    There is a great interest in studying dynamic characteristics of the financial time series of the daily stock closing price in different regions. Multi-scale entropy (MSE) is effective, mainly in quantifying the complexity of time series on different time scales. This paper applies a new method for financial stability from the perspective of MSE based on skewness and kurtosis. To better understand the superior coarse-graining method for the different kinds of stock indexes, we take into account the developmental characteristics of the three continents of Asia, North America and European stock markets. We study the volatility of different financial time series in addition to analyze the similarities and differences of coarsening time series from the perspective of skewness and kurtosis. A kind of corresponding relationship between the entropy value of stock sequences and the degree of stability of financial markets, were observed. The three stocks which have particular characteristics in the eight piece of stock sequences were discussed, finding the fact that it matches the result of applying the MSE method to showing results on a graph. A comparative study is conducted to simulate over synthetic and real world data. Results show that the modified method is more effective to the change of dynamics and has more valuable information. The result is obtained at the same time, finding the results of skewness and kurtosis discrimination is obvious, but also more stable.

  12. Effect of Phase Response Curve Skew on Synchronization with and without Conduction Delays

    Directory of Open Access Journals (Sweden)

    Carmen eCanavier

    2013-12-01

    Full Text Available A central problem in cortical processing including sensory binding and attentional gating is how neurons can synchronize their responses with zero or near-zero time lag. For a spontaneously firing neuron, an input from another neuron can delay or advance the next spike by different amounts depending upon the timing of the input relative to the previous spike. This information constitutes the phase response curve (PRC. We present a simple graphical method for determining the effect of PRC shape on synchronization tendencies and illustrate it using type 1 PRCs, which consist entirely of advances (delays in response to excitation (inhibition. We obtained the following generic solutions for type 1 PRCs, which include the pulse coupled leaky integrate and fire model. For pairs with mutual excitation, exact synchrony can be stable for strong coupling because of the stabilizing effect of the causal limit region of the PRC in which an input triggers a spike immediately upon arrival. However, synchrony is unstable for short delays, because delayed inputs arrive during a refractory period and cannot trigger an immediate spike. Right skew destabilizes antiphase and enables modes with time lags that grow as the conduction delay is increased. Therefore, right skew favors near-synchrony at short conduction delays and a gradual transition between synchrony and antiphase for pairs coupled by mutual excitation. For pairs with mutual inhibition, zero time lag synchrony is stable for conduction delays ranging from zero to a substantial fraction of the period for pairs. However, for right skew there is a preferred antiphase mode at short delays. In contrast to mutual excitation, left skew destabilizes antiphase for mutual inhibition so that synchrony dominates at short delays as well. These pairwise synchronization tendencies constrain the synchronization properties of neurons embedded in larger networks.

  13. Random skew plane partitions and the Pearcey process

    DEFF Research Database (Denmark)

    Reshetikhin, Nicolai; Okounkov, Andrei

    2007-01-01

    We study random skew 3D partitions weighted by q vol and, specifically, the q → 1 asymptotics of local correlations near various points of the limit shape. We obtain sine-kernel asymptotics for correlations in the bulk of the disordered region, Airy kernel asymptotics near a general point of the ...

  14. Polynomial combinatorial algorithms for skew-bisubmodular function minimization

    NARCIS (Netherlands)

    S. Fujishige (Satoru); S.-I. Tanigawa (Shin-Ichi)

    2017-01-01

    textabstractHuber et al. (SIAM J Comput 43:1064–1084, 2014) introduced a concept of skew bisubmodularity, as a generalization of bisubmodularity, in their complexity dichotomy theorem for valued constraint satisfaction problems over the three-value domain, and Huber and Krokhin (SIAM J Discrete Math

  15. Time Skew Estimator for Dual-Polarization QAM Transmitters

    DEFF Research Database (Denmark)

    Medeiros Diniz, Júlio César; Da Ros, Francesco; Jones, Rasmus Thomas

    2017-01-01

    A simple method for joint estimation of transmitter’s in-phase/quadrature and inter-polarization time skew is proposed and experimentally demonstrated. The method is based on clock tone extraction of a photodetected signal and genetic algorithm. The maximum estimation error was 0.5 ps....

  16. A variational analysis for large deflection of skew plates under ...

    African Journals Online (AJOL)

    In the present paper, the static behaviour of thin isotropic skew plates under uniformly distributed load is analyzed with the geometric nonlinearity of the model properly handled. A variational method based on total potential energy has been implemented through assumed displacement field. The computational work has ...

  17. Asymmetric skew Bessel processes and their applications to finance

    NARCIS (Netherlands)

    Decamps, M.; Goovaerts, M.J.; Schoutens, W.

    2006-01-01

    In this paper, we extend the Harrison and Shepp's construction of the skew Brownian motion (1981) and we obtain a diffusion similar to the two-dimensional Bessel process with speed and scale densities discontinuous at one point. Natural generalizations to multi-dimensional and fractional order

  18. Parameterizing unconditional skewness in models for financial time series

    DEFF Research Database (Denmark)

    He, Changli; Silvennoinen, Annastiina; Teräsvirta, Timo

    In this paper we consider the third-moment structure of a class of time series models. It is often argued that the marginal distribution of financial time series such as returns is skewed. Therefore it is of importance to know what properties a model should possess if it is to accommodate...

  19. Entrepreneurship and Financial Incentives of Return, Risk, and Skew

    DEFF Research Database (Denmark)

    Berkhout, Peter; Hartog, Joop; Van Praag, Mirjam

    2016-01-01

    . The focus on earnings forgone may help to solve the lack of robust empirical support for the effect of financial incentives on the decision to become an entrepreneur. We find, consistent with standard theory, that a higher mean, lower variance, and higher skew in the relevant wage distribution reduce...

  20. Prototyping and Characterization of an Adjustable Skew Angle Single Gimbal Control Moment Gyroscope

    Science.gov (United States)

    2015-03-01

    plates, two curved supports for the gimbal frame, and the box shaped mount base with the four roller rods basically carried through all further design... Underwood , “Experimental Testing of a CMG Cluster for Agile Microsatellites,” Journal-British Interplanetary Society, vol. 57, no. 9/10, pp. 318–324

  1. Skew-t partially linear mixed-effects models for AIDS clinical studies.

    Science.gov (United States)

    Lu, Tao

    2016-01-01

    We propose partially linear mixed-effects models with asymmetry and missingness to investigate the relationship between two biomarkers in clinical studies. The proposed models take into account irregular time effects commonly observed in clinical studies under a semiparametric model framework. In addition, commonly assumed symmetric distributions for model errors are substituted by asymmetric distribution to account for skewness. Further, informative missing data mechanism is accounted for. A Bayesian approach is developed to perform parameter estimation simultaneously. The proposed model and method are applied to an AIDS dataset and comparisons with alternative models are performed.

  2. NET SALARY ADJUSTMENT

    CERN Multimedia

    Finance Division

    2001-01-01

    On 15 June 2001 the Council approved the correction of the discrepancy identified in the net salary adjustment implemented on 1st January 2001 by retroactively increasing the scale of basic salaries to achieve the 2.8% average net salary adjustment approved in December 2000. We should like to inform you that the corresponding adjustment will be made to your July salary. Full details of the retroactive adjustments will consequently be shown on your pay slip.

  3. Joint IQ Skew and Chromatic Dispersion Estimation for Coherent Optical Communication Receivers

    DEFF Research Database (Denmark)

    Medeiros Diniz, Júlio César; Porto da Silva, Edson; Piels, Molly

    2016-01-01

    A low-complexity scanning method for joint estimation of receiver IQ skew and chromatic dispersion is proposed. This method shows less than 1 ps skew error for a 1200-km 32-GBd DP-16QAM optical transmission experiment.......A low-complexity scanning method for joint estimation of receiver IQ skew and chromatic dispersion is proposed. This method shows less than 1 ps skew error for a 1200-km 32-GBd DP-16QAM optical transmission experiment....

  4. Regularized multivariate regression models with skew-t error distributions

    KAUST Repository

    Chen, Lianfu

    2014-06-01

    We consider regularization of the parameters in multivariate linear regression models with the errors having a multivariate skew-t distribution. An iterative penalized likelihood procedure is proposed for constructing sparse estimators of both the regression coefficient and inverse scale matrices simultaneously. The sparsity is introduced through penalizing the negative log-likelihood by adding L1-penalties on the entries of the two matrices. Taking advantage of the hierarchical representation of skew-t distributions, and using the expectation conditional maximization (ECM) algorithm, we reduce the problem to penalized normal likelihood and develop a procedure to minimize the ensuing objective function. Using a simulation study the performance of the method is assessed, and the methodology is illustrated using a real data set with a 24-dimensional response vector. © 2014 Elsevier B.V.

  5. Micromagnetic recording model of writer geometry effects at skew

    Science.gov (United States)

    Plumer, M. L.; Bozeman, S.; van Ek, J.; Michel, R. P.

    2006-04-01

    The effects of the pole-tip geometry at the air-bearing surface on perpendicular recording at a skew angle are examined through modeling and spin-stand test data. Head fields generated by the finite element method were used to record transitions within our previously described micromagnetic recording model. Write-field contours for a variety of square, rectangular, and trapezoidal pole shapes were evaluated to determine the impact of geometry on field contours. Comparing results for recorded track width, transition width, and media signal to noise ratio at 0° and 15° skew demonstrate the benefits of trapezoidal and reduced aspect-ratio pole shapes. Consistency between these modeled results and test data is demonstrated.

  6. Yaw-modelling using a skewed vortex cylinder

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre

    2017-01-01

    The cylindrical vortex wake model presented in Chap. 17 for the case of uniform inflow is extended in the current chapter to the case of yawed inflow. Generalities regarding yaw are presented in Sect. 6.1 and only the skewed cylindrical vortex model is presented in this chapter. The chapter starts...... with a literature review on the topic of yaw-models and vorticity-based methods. The description of the model follows. The novelty of the current model is that the assumption of infinite tip-speed ratio is relaxed. The bound vorticity is assumed to be identical to the case of uniform inflow but the vortex cylinder...... and the root vortex are skewed with respect to the normal of the rotor disk. Closed form formulae for the induced velocities are provided. They can only be evaluated analytically for a limited part of the domain. A numerical integration is required to obtain the velocity everywhere in the domain. The numerical...

  7. Speckles generated by skewed, short-coherence light beams

    International Nuclear Information System (INIS)

    Brogioli, D; Salerno, D; Ziano, R; Mantegazza, F; Croccolo, F

    2011-01-01

    When a coherent laser beam impinges on a random sample (e.g. a colloidal suspension), the scattered light exhibits characteristic speckles. If the temporal coherence of the light source is too short, then the speckles disappear, along with the possibility of performing homodyne or heterodyne scattering detection or photon correlation spectroscopy. Here we investigate the scattering of a so-called ‘skewed coherence beam’, i.e. a short-coherence beam modified such that the field is coherent within slabs that are skewed with respect to the wave fronts. We show that such a beam generates speckles and can be used for heterodyne scattering detection, despite its short temporal coherence. Moreover, we show that the heterodyne signal is not affected by multiple scattering. We suggest that the phenomenon presented here can be used as a means of carrying out heterodyne scattering measurement with any short-coherence radiation, including x-rays. (paper)

  8. MEASURING LOCAL GRADIENT AND SKEW QUADRUPOLE ERRORS IN RHIC IRS

    International Nuclear Information System (INIS)

    CARDONA, J.; PEGGS, S.; PILAT, R.; PTITSYN, V.

    2004-01-01

    The measurement of local linear errors at RHIC interaction regions using an ''action and phase'' analysis of difference orbits has already been presented [2]. This paper evaluates the accuracy of this technique using difference orbits that were taken when known gradient errors and skew quadrupole errors were intentionally introduced. It also presents action and phase analysis of simulated orbits when controlled errors are intentionally placed in a RHIC simulation model

  9. Incorporating Skew into RMS Surface Roughness Probability Distribution

    Science.gov (United States)

    Stahl, Mark T.; Stahl, H. Philip.

    2013-01-01

    The standard treatment of RMS surface roughness data is the application of a Gaussian probability distribution. This handling of surface roughness ignores the skew present in the surface and overestimates the most probable RMS of the surface, the mode. Using experimental data we confirm the Gaussian distribution overestimates the mode and application of an asymmetric distribution provides a better fit. Implementing the proposed asymmetric distribution into the optical manufacturing process would reduce the polishing time required to meet surface roughness specifications.

  10. Few Skewed Results from IOTA Interferometer YSO Disk Survey

    Science.gov (United States)

    Monnier, J. D.; Millan-Gabet, R.; Berger, J.-P.; Pedretti, E.; Traub, W.; Schloerb, F. P.

    2005-12-01

    The 3-telescope IOTA interferometer is capable of measuring closure phases for dozens of Herbig Ae/Be stars in the near-infrared. The closure phase unambiguously identifies deviations from centro-symmetry (i.e., skew) in the brightness distribution, at the scale of 4 milliarcseconds (sub-AU physical scales) for our work. Indeed, hot dust emission from the inner circumstellar accretion disk is expected to be skewed for (generic) flared disks viewed at intermediate inclination angles, as has been observed for LkHa 101. Surprisingly, we find very little evidence for skewed disk emission in our IOTA3 sample, setting strong constraints on the geometry of the inner disk. In particular, we rule out the currently-popular model of a VERTICAL hot inner wall of dust at the sublimation radius. Instead, our data is more consistent with a curved inner wall that bends away from the midplane as might be expected from the pressure-dependence of dust sublimation or limited absorption of stellar luminosity in the disk midplane by gas.

  11. Validation of an Acoustic Impedance Prediction Model for Skewed Resonators

    Science.gov (United States)

    Howerton, Brian M.; Parrott, Tony L.

    2009-01-01

    An impedance prediction model was validated experimentally to determine the composite impedance of a series of high-aspect ratio slot resonators incorporating channel skew and sharp bends. Such structures are useful for packaging acoustic liners into constrained spaces for turbofan noise control applications. A formulation of the Zwikker-Kosten Transmission Line (ZKTL) model, incorporating the Richards correction for rectangular channels, is used to calculate the composite normalized impedance of a series of six multi-slot resonator arrays with constant channel length. Experimentally, acoustic data was acquired in the NASA Langley Normal Incidence Tube over the frequency range of 500 to 3500 Hz at 120 and 140 dB OASPL. Normalized impedance was reduced using the Two-Microphone Method for the various combinations of channel skew and sharp 90o and 180o bends. Results show that the presence of skew and/or sharp bends does not significantly alter the impedance of a slot resonator as compared to a straight resonator of the same total channel length. ZKTL predicts the impedance of such resonators very well over the frequency range of interest. The model can be used to design arrays of slot resonators that can be packaged into complex geometries heretofore unsuitable for effective acoustic treatment.

  12. Skewed matrilineal genetic composition in a small wild chimpanzee community.

    Science.gov (United States)

    Shimada, Makoto K; Hayakawa, Sachiko; Fujita, Shiho; Sugiyama, Yukimaru; Saitou, Naruya

    2009-01-01

    Maternal kinship is important in primate societies because it affects individual behaviour as well as the sustainability of populations. All members of the Bossou chimpanzee community are descended from 8 individuals (herein referred to as original adults) who were already adults or subadults when field observations were initiated in 1976 and whose genetic relationships were unknown. Sequencing of the control region on the maternally inherited mtDNA revealed that 4 (1 male and 3 females) of the 8 original adults shared an identical haplotype. We investigated the effects of the skewed distribution of mtDNA haplotypes on the following two outcomes. First, we demonstrated that the probability of mtDNA haplotype extinction would be increased under such a skewed composition in a small community. Second, the ratio of potential mating candidates to competitors is likely to decrease if chimpanzees become aware of maternal kinship and avoid incest. We estimated that the magnitude of the decrease in the ratio is 10 times greater in males than in females. Here we demonstrate a scenario in which this matrilineal skewness in a small community accelerates extinction of mtDNA haplotype, which will make it more difficult to find a suitable mate within the community. 2008 S. Karger AG, Basel.

  13. Screening Immunomodulators To Skew the Antigen-Specific Autoimmune Response.

    Science.gov (United States)

    Northrup, Laura; Sullivan, Bradley P; Hartwell, Brittany L; Garza, Aaron; Berkland, Cory

    2017-01-03

    Current therapies to treat autoimmune diseases often result in side effects such as nonspecific immunosuppression. Therapies that can induce antigen-specific immune tolerance provide an opportunity to reverse autoimmunity and mitigate the risks associated with global immunosuppression. In an effort to induce antigen-specific immune tolerance, co-administration of immunomodulators with autoantigens has been investigated in an effort to reprogram autoimmunity. To date, identifying immunomodulators that may skew the antigen-specific immune response has been ad hoc at best. To address this need, we utilized splenocytes obtained from mice with experimental autoimmune encephalomyelitis (EAE) in order to determine if certain immunomodulators may induce markers of immune tolerance following antigen rechallenge. Of the immunomodulatory compounds investigated, only dexamethasone modified the antigen-specific immune response by skewing the cytokine response and decreasing T-cell populations at a concentration corresponding to a relevant in vivo dose. Thus, antigen-educated EAE splenocytes provide an ex vivo screen for investigating compounds capable of skewing the antigen-specific immune response, and this approach could be extrapolated to antigen-educated cells from other diseases or human tissues.

  14. Convexity Adjustments

    DEFF Research Database (Denmark)

    M. Gaspar, Raquel; Murgoci, Agatha

    2010-01-01

    A convexity adjustment (or convexity correction) in fixed income markets arises when one uses prices of standard (plain vanilla) products plus an adjustment to price nonstandard products. We explain the basic and appealing idea behind the use of convexity adjustments and focus on the situations...

  15. A method for generating skewed random numbers using two overlapping uniform distributions

    International Nuclear Information System (INIS)

    Ermak, D.L.; Nasstrom, J.S.

    1995-02-01

    The objective of this work was to implement and evaluate a method for generating skewed random numbers using a combination of uniform random numbers. The method provides a simple and accurate way of generating skewed random numbers from the specified first three moments without an a priori specification of the probability density function. We describe the procedure for generating skewed random numbers from unifon-n random numbers, and show that it accurately produces random numbers with the desired first three moments over a range of skewness values. We also show that in the limit of zero skewness, the distribution of random numbers is an accurate approximation to the Gaussian probability density function. Future work win use this method to provide skewed random numbers for a Langevin equation model for diffusion in skewed turbulence

  16. Meta-analysis of breast cancer mortality benefit and overdiagnosis adjusted for adherence: improving information on the effects of attending screening mammography

    Science.gov (United States)

    Jacklyn, Gemma; Glasziou, Paul; Macaskill, Petra; Barratt, Alexandra

    2016-01-01

    Background: Women require information about the impact of regularly attending screening mammography on breast cancer mortality and overdiagnosis to make informed decisions. To provide this information we aimed to meta-analyse randomised controlled trials adjusted for adherence to the trial protocol. Methods: Nine screening mammography trials used in the Independent UK Breast Screening Report were selected. Extending an existing approach to adjust intention-to-treat (ITT) estimates for less than 100% adherence rates, we conducted a random-effects meta-analysis. This produced a combined deattenuated prevented fraction and a combined deattenuated percentage risk of overdiagnosis. Results: In women aged 39–75 years invited to screen, the prevented fraction of breast cancer mortality at 13-year follow-up was 0.22 (95% CI 0.15–0.28) and it increased to 0.30 (95% CI 0.18–0.42) with deattenuation. In women aged 40–69 years invited to screen, the ITT percentage risk of overdiagnosis during the screening period was 19.0% (95% CI 15.2–22.7%), deattenuation increased this to 29.7% (95% CI 17.8–41.5%). Conclusions: Adjustment for nonadherence increased the size of the mortality benefit and risk of overdiagnosis by up to 50%. These estimates are more appropriate when developing quantitative information to support individual decisions about attending screening mammography. PMID:27124337

  17. Forecasting stock market volatility: Do realized skewness and kurtosis help?

    Science.gov (United States)

    Mei, Dexiang; Liu, Jing; Ma, Feng; Chen, Wang

    2017-09-01

    In this study, we investigate the predictability of the realized skewness (RSK) and realized kurtosis (RKU) to stock market volatility, that has not been addressed in the existing studies. Out-of-sample results show that RSK, which can significantly improve forecast accuracy in mid- and long-term, is more powerful than RKU in forecasting volatility. Whereas these variables are useless in short-term forecasting. Furthermore, we employ the realized kernel (RK) for the robustness analysis and the conclusions are consistent with the RV measures. Our results are of great importance for portfolio allocation and financial risk management.

  18. Scale and shape mixtures of multivariate skew-normal distributions

    KAUST Repository

    Arellano-Valle, Reinaldo B.

    2018-02-26

    We introduce a broad and flexible class of multivariate distributions obtained by both scale and shape mixtures of multivariate skew-normal distributions. We present the probabilistic properties of this family of distributions in detail and lay down the theoretical foundations for subsequent inference with this model. In particular, we study linear transformations, marginal distributions, selection representations, stochastic representations and hierarchical representations. We also describe an EM-type algorithm for maximum likelihood estimation of the parameters of the model and demonstrate its implementation on a wind dataset. Our family of multivariate distributions unifies and extends many existing models of the literature that can be seen as submodels of our proposal.

  19. PARAMETRIC STUDY OF SKEW ANGLE ON BOX GIRDER BRIDGE DECK

    OpenAIRE

    Shrikant D. Bobade *, Dr. Valsson Varghese

    2016-01-01

    Box girder bridge deck, is the most common type of bridges in world and India, it consists of several Slab or girders. The span in the direction of the roadway and connected across their tops and bottoms by a thin continuous structural stab, the longitudinal box girders can be made of steel or concrete. The Simple supported single span concrete bridge deck is presented in present study. Skewed bridges are suitable in highway design when the geometry of straight bridges is not possible. The sk...

  20. Frequent Pairs in Data Streams: Exploiting Parallelism and Skew

    DEFF Research Database (Denmark)

    Campagna, Andrea; Kutzkow, Konstantin; Pagh, Rasmus

    2011-01-01

    We introduce the Pair Streaming Engine (PairSE) that detects frequent pairs in a data stream of transactions. Our algorithm finds the most frequent pairs with high probability, and gives tight bounds on their frequency. It is particularly space efficient for skewed distribution of pair supports...... items mining in data streams. We show how to efficiently scale these approaches to handle large transactions. We report experimental results showcasing precision and recall of our method. In particular, we find that often our method achieves excellent precision, returning identical upper and lower...... bounds on the supports of the most frequent pairs....

  1. 78 FR 36231 - 60-Day Notice of Proposed Information Collection: FHA-Disclosure of Adjustable Rate Mortgages...

    Science.gov (United States)

    2013-06-17

    ... Relay Service at (800) 877-8339. FOR FURTHER INFORMATION CONTACT: Joanne Kuzma, Director, Office of... calling the toll-free Federal Relay Service at (800) 877-8339. Copies of available documents submitted to... techniques or other forms of information technology, e.g., permitting electronic submission of responses. HUD...

  2. Skewed steel bridges, part ii : cross-frame and connection design to ensure brace effectiveness : technical summary.

    Science.gov (United States)

    2017-08-01

    Skewed bridges in Kansas are often designed such that the cross-frames are carried parallel to the skew angle up to 40, while many other states place cross-frames perpendicular to the girder for skew angles greater than 20. Skewed-parallel cross-...

  3. Skewed steel bridges, part ii : cross-frame and connection design to ensure brace effectiveness : final report.

    Science.gov (United States)

    2017-08-01

    Skewed bridges in Kansas are often designed such that the cross-frames are carried parallel to the skew angle up to 40, while many other states place cross-frames perpendicular to the girder for skew angles greater than 20. Skewed-parallel cross-...

  4. Crossover ensembles of random matrices and skew-orthogonal polynomials

    International Nuclear Information System (INIS)

    Kumar, Santosh; Pandey, Akhilesh

    2011-01-01

    Highlights: → We study crossover ensembles of Jacobi family of random matrices. → We consider correlations for orthogonal-unitary and symplectic-unitary crossovers. → We use the method of skew-orthogonal polynomials and quaternion determinants. → We prove universality of spectral correlations in crossover ensembles. → We discuss applications to quantum conductance and communication theory problems. - Abstract: In a recent paper (S. Kumar, A. Pandey, Phys. Rev. E, 79, 2009, p. 026211) we considered Jacobi family (including Laguerre and Gaussian cases) of random matrix ensembles and reported exact solutions of crossover problems involving time-reversal symmetry breaking. In the present paper we give details of the work. We start with Dyson's Brownian motion description of random matrix ensembles and obtain universal hierarchic relations among the unfolded correlation functions. For arbitrary dimensions we derive the joint probability density (jpd) of eigenvalues for all transitions leading to unitary ensembles as equilibrium ensembles. We focus on the orthogonal-unitary and symplectic-unitary crossovers and give generic expressions for jpd of eigenvalues, two-point kernels and n-level correlation functions. This involves generalization of the theory of skew-orthogonal polynomials to crossover ensembles. We also consider crossovers in the circular ensembles to show the generality of our method. In the large dimensionality limit, correlations in spectra with arbitrary initial density are shown to be universal when expressed in terms of a rescaled symmetry breaking parameter. Applications of our crossover results to communication theory and quantum conductance problems are also briefly discussed.

  5. FLECHT low flooding rate skewed test series data report

    International Nuclear Information System (INIS)

    Rosal, E.R.; Conway, C.E.; Krepinevich, M.C.

    1977-05-01

    The FLECHT Low Flooding Rate Tests were conducted in an improved original FLECHT Test Facility to provide heat transfer coefficient and entrainment data at forced flooding rates of 1 in./sec. and with electrically heated rod bundles which had cosine and top skewed axial power profiles. The top-skewed axial power profile test series has now been successfully completed and is here reported. For these tests the rod bundle was enclosed in a low mass cylindrical housing which would minimize the wall housing effects encountered in the cosine test series. These tests examined the effects of initial clad temperature, variable stepped and continuously variable flooding rates, housing heat release, rod peak power, constant low flooding rates, coolant subcooling, hot and cold channel entrainment, and bundle stored and generated power. Data obtained in runs which met the test specifications are reported here, and include rod clad temperatures, turn around and quench times, heat transfer coefficients, inlet flooding rates, overall mass balances, differential pressures and calculated void fractions in the test section, thimble wall and steam temperatures, and exhaust steam and liquid carryover rates

  6. Skewed sex ratios in India: "physician, heal thyself".

    Science.gov (United States)

    Patel, Archana B; Badhoniya, Neetu; Mamtani, Manju; Kulkarni, Hemant

    2013-06-01

    Sex selection, a gender discrimination of the worst kind, is highly prevalent across all strata of Indian society. Physicians have a crucial role in this practice and implementation of the Indian Government's Pre-Natal Diagnostic Techniques Act in 1996 to prevent the misuse of ultrasound techniques for the purpose of prenatal sex determination. Little is known about family preferences, let alone preferences among families of physicians. We investigated the sex ratios in 946 nuclear families with 1,624 children, for which either one or both parents were physicians. The overall child sex ratio was more skewed than the national average of 914. The conditional sex ratios decreased with increasing number of previous female births, and a previous birth of a daughter in the family was associated with a 38 % reduced likelihood of a subsequent female birth. The heavily skewed sex ratios in the families of physicians are indicative of a deeply rooted social malady that could pose a critical challenge in correcting the sex ratios in India.

  7. Approximate median regression for complex survey data with skewed response.

    Science.gov (United States)

    Fraser, Raphael André; Lipsitz, Stuart R; Sinha, Debajyoti; Fitzmaurice, Garrett M; Pan, Yi

    2016-12-01

    The ready availability of public-use data from various large national complex surveys has immense potential for the assessment of population characteristics using regression models. Complex surveys can be used to identify risk factors for important diseases such as cancer. Existing statistical methods based on estimating equations and/or utilizing resampling methods are often not valid with survey data due to complex survey design features. That is, stratification, multistage sampling, and weighting. In this article, we accommodate these design features in the analysis of highly skewed response variables arising from large complex surveys. Specifically, we propose a double-transform-both-sides (DTBS)'based estimating equations approach to estimate the median regression parameters of the highly skewed response; the DTBS approach applies the same Box-Cox type transformation twice to both the outcome and regression function. The usual sandwich variance estimate can be used in our approach, whereas a resampling approach would be needed for a pseudo-likelihood based on minimizing absolute deviations (MAD). Furthermore, the approach is relatively robust to the true underlying distribution, and has much smaller mean square error than a MAD approach. The method is motivated by an analysis of laboratory data on urinary iodine (UI) concentration from the National Health and Nutrition Examination Survey. © 2016, The International Biometric Society.

  8. Guided ultrasonic wave beam skew in silicon wafers

    Science.gov (United States)

    Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul

    2018-04-01

    In the photovoltaic industry, monocrystalline silicon wafers are employed for solar cells with high conversion efficiency. Micro-cracks induced by the cutting process in the thin wafers can lead to brittle wafer fracture. Guided ultrasonic waves would offer an efficient methodology for the in-process non-destructive testing of wafers to assess micro-crack density. The material anisotropy of the monocrystalline silicon leads to variations of the guided wave characteristics, depending on the propagation direction relative to the crystal orientation. Selective guided ultrasonic wave excitation was achieved using a contact piezoelectric transducer with custom-made wedges for the A0 and S0 Lamb wave modes and a transducer holder to achieve controlled contact pressure and orientation. The out-of-plane component of the guided wave propagation was measured using a non-contact laser interferometer. The phase slowness (velocity) of the two fundamental Lamb wave modes was measured experimentally for varying propagation directions relative to the crystal orientation and found to match theoretical predictions. Significant wave beam skew was observed experimentally, especially for the S0 mode, and investigated from 3D finite element simulations. Good agreement was found with the theoretical predictions based on nominal material properties of the silicon wafer. The important contribution of guided wave beam skewing effects for the non-destructive testing of silicon wafers was demonstrated.

  9. 75 FR 32911 - Notice of Informational Meeting for the i6 Challenge Under EDA's Economic Adjustment Assistance...

    Science.gov (United States)

    2010-06-10

    ... new, multi-agency innovation competition led by the Economic Development Administration (EDA), a... are in need of additional support, in order to strengthen regional innovation ecosystems. Applicants... DEPARTMENT OF COMMERCE Economic Development Administration Notice of Informational Meeting for the...

  10. On the Effects of Wind Turbine Wake Skew Caused by Wind Veer: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Churchfield, Matthew J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sirnivas, Senu [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-03-01

    Because of Coriolis forces caused by the Earth's rotation, the structure of the atmospheric boundary layer often contains wind-direction change with height, also known as wind-direction veer. Under low turbulence conditions, such as in stably stratified atmospheric conditions, this veer can be significant, even across the vertical extent of a wind turbine's rotor disk. The veer then causes the wind turbine wake to skew as it advects downstream. This wake skew has been observed both experimentally and numerically. In this work, we attempt to examine the wake skewing process in some detail, and quantify how differently a skewed wake versus a non skewed wake affects a downstream turbine. We do this by performing atmospheric large-eddy simulations to create turbulent inflow winds with and without veer. In the veer case, there is a roughly 8 degree wind direction change across the turbine rotor. We then perform subsequent large-eddy simulations using these inflow data with an actuator line rotor model to create wakes. The turbine modeled is a large, modern, offshore, multimegawatt turbine. We examine the unsteady wake data in detail and show that the skewed wake recovers faster than the non skewed wake. We also show that the wake deficit does not skew to the same degree that a passive tracer would if subject to veered inflow. Last, we use the wake data to place a hypothetical turbine 9 rotor diameters downstream by running aeroelastic simulations with the simulated wake data. We see differences in power and loads if this downstream turbine is subject to a skewed or non skewed wake. We feel that the differences observed between the skewed and nonskewed wake are important enough that the skewing effect should be included in engineering wake models.

  11. On the Effects of Wind Turbine Wake Skew Caused by Wind Veer

    Energy Technology Data Exchange (ETDEWEB)

    Churchfield, Matthew J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sirnivas, Senu [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-01-12

    Because of Coriolis forces caused by the Earth's rotation, the structure of the atmospheric boundary layer often contains wind-direction change with height, also known as wind-direction veer. Under low turbulence conditions, such as in stably stratified atmospheric conditions, this veer can be significant, even across the vertical extent of a wind turbine's rotor disk. The veer then causes the wind turbine wake to skew as it advects downstream. This wake skew has been observed both experimentally and numerically. In this work, we attempt to examine the wake skewing process in some detail, and quantify how differently a skewed wake versus a non skewed wake affects a downstream turbine. We do this by performing atmospheric large-eddy simulations to create turbulent inflow winds with and without veer. In the veer case, there is a roughly 8 degree wind direction change across the turbine rotor. We then perform subsequent large-eddy simulations using these inflow data with an actuator line rotor model to create wakes. The turbine modeled is a large, modern, offshore, multimegawatt turbine. We examine the unsteady wake data in detail and show that the skewed wake recovers faster than the non skewed wake. We also show that the wake deficit does not skew to the same degree that a passive tracer would if subject to veered inflow. Last, we use the wake data to place a hypothetical turbine 9 rotor diameters downstream by running aeroelastic simulations with the simulated wake data. We see differences in power and loads if this downstream turbine is subject to a skewed or non skewed wake. We feel that the differences observed between the skewed and nonskewed wake are important enough that the skewing effect should be included in engineering wake models.

  12. Skew cyclic codes over F_q+uF_q+vF_q+uvF_q

    Directory of Open Access Journals (Sweden)

    Ting Yao

    2015-09-01

    Full Text Available In this paper, we study skew cyclic codes over the ring $R=F_q+uF_q+vF_q+uvF_q$, where $u^{2}=u,v^{2}=v,uv=vu$, $q=p^{m}$ and $p$ is an odd prime. We investigate the structural properties of skew cyclic codes over $R$ through a decomposition theorem. Furthermore, we give a formula for the number of skew cyclic codes of length $n$ over $R.$

  13. Risk-adjusted capitation based on the Diagnostic Cost Group Model: an empirical evaluation with health survey information

    NARCIS (Netherlands)

    L.M. Lamers (Leida)

    1999-01-01

    textabstractOBJECTIVE: To evaluate the predictive accuracy of the Diagnostic Cost Group (DCG) model using health survey information. DATA SOURCES/STUDY SETTING: Longitudinal data collected for a sample of members of a Dutch sickness fund. In the Netherlands the sickness

  14. 77 FR 7243 - Agency Information Collection (Survey of Post-Deployment Adjustment Among OEF and OIF Veterans...

    Science.gov (United States)

    2012-02-10

    ... on the collection of information through www.Regulations.gov ; or to VA's OMB Desk Officer, OMB Human... combat and sexual trauma during deployment. VA will use the data to identify how homecoming experiences... hours. Estimated Average Burden per Respondent: 20 minutes. Frequency of Response: On occasion...

  15. Multivariate log-skew-elliptical distributions with applications to precipitation data

    KAUST Repository

    Marchenko, Yulia V.

    2009-07-13

    We introduce a family of multivariate log-skew-elliptical distributions, extending the list of multivariate distributions with positive support. We investigate their probabilistic properties such as stochastic representations, marginal and conditional distributions, and existence of moments, as well as inferential properties. We demonstrate, for example, that as for the log-t distribution, the positive moments of the log-skew-t distribution do not exist. Our emphasis is on two special cases, the log-skew-normal and log-skew-t distributions, which we use to analyze US national (univariate) and regional (multivariate) monthly precipitation data. © 2009 John Wiley & Sons, Ltd.

  16. Multivariate log-skew-elliptical distributions with applications to precipitation data

    KAUST Repository

    Marchenko, Yulia V.; Genton, Marc G.

    2009-01-01

    We introduce a family of multivariate log-skew-elliptical distributions, extending the list of multivariate distributions with positive support. We investigate their probabilistic properties such as stochastic representations, marginal and conditional distributions, and existence of moments, as well as inferential properties. We demonstrate, for example, that as for the log-t distribution, the positive moments of the log-skew-t distribution do not exist. Our emphasis is on two special cases, the log-skew-normal and log-skew-t distributions, which we use to analyze US national (univariate) and regional (multivariate) monthly precipitation data. © 2009 John Wiley & Sons, Ltd.

  17. Comparative study of reproductive skew and pair-bond stability using genealogies from 80 small-scale human societies.

    Science.gov (United States)

    Ellsworth, Ryan M; Shenk, Mary K; Bailey, Drew H; Walker, Robert S

    2016-05-01

    Genealogies contain information on the prevalence of different sibling types that result from past reproductive behavior. Full sibling sets stem from stable monogamy, paternal half siblings primarily indicate male reproductive skew, and maternal half siblings reflect unstable pair bonds. Full and half sibling types are calculated for a total of 61,181 siblings from published genealogies for 80 small-scale societies, including foragers, horticulturalists, agriculturalists, and pastoralists from around the world. Most siblings are full (61%) followed by paternal half siblings (27%) and maternal half siblings (13%). Paternal half siblings are positively correlated with more polygynous marriages, higher at low latitudes, and slightly higher in nonforagers, Maternal half sibling fractions are slightly higher at low latitudes but do not vary with subsistence. Partible paternity societies in Amazonia have more paternal half siblings indicating higher male reproductive skew. Sibling counts from genealogies provide a convenient method to simultaneously investigate the reproductive skew and pair-bond stability dimensions of human mating systems cross-culturally. Am. J. Hum. Biol. 28:335-342, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  18. Skew-orthogonal polynomials and random matrix theory

    CERN Document Server

    Ghosh, Saugata

    2009-01-01

    Orthogonal polynomials satisfy a three-term recursion relation irrespective of the weight function with respect to which they are defined. This gives a simple formula for the kernel function, known in the literature as the Christoffel-Darboux sum. The availability of asymptotic results of orthogonal polynomials and the simple structure of the Christoffel-Darboux sum make the study of unitary ensembles of random matrices relatively straightforward. In this book, the author develops the theory of skew-orthogonal polynomials and obtains recursion relations which, unlike orthogonal polynomials, depend on weight functions. After deriving reduced expressions, called the generalized Christoffel-Darboux formulas (GCD), he obtains universal correlation functions and non-universal level densities for a wide class of random matrix ensembles using the GCD. The author also shows that once questions about higher order effects are considered (questions that are relevant in different branches of physics and mathematics) the ...

  19. Noise measurement from magnitude MRI using local estimates of variance and skewness

    International Nuclear Information System (INIS)

    Rajan, Jeny; Poot, Dirk; Juntu, Jaber; Sijbers, Jan

    2010-01-01

    In this note, we address the estimation of the noise level in magnitude magnetic resonance (MR) images in the absence of background data. Most of the methods proposed earlier exploit the Rayleigh distributed background region in MR images to estimate the noise level. These methods, however, cannot be used for images where no background information is available. In this note, we propose two different approaches for noise level estimation in the absence of the image background. The first method is based on the local estimation of the noise variance using maximum likelihood estimation and the second method is based on the local estimation of the skewness of the magnitude data distribution. Experimental results on synthetic and real MR image datasets show that the proposed estimators accurately estimate the noise level in a magnitude MR image, even without background data. (note)

  20. Asymmetric adjustment

    NARCIS (Netherlands)

    2010-01-01

    A method of adjusting a signal processing parameter for a first hearing aid and a second hearing aid forming parts of a binaural hearing aid system to be worn by a user is provided. The binaural hearing aid system comprises a user specific model representing a desired asymmetry between a first ear

  1. Simple skew category algebras associated with minimal partially defined dynamical systems

    DEFF Research Database (Denmark)

    Nystedt, Patrik; Öinert, Per Johan

    2013-01-01

    In this article, we continue our study of category dynamical systems, that is functors s from a category G to Topop, and their corresponding skew category algebras. Suppose that the spaces s(e), for e∈ob(G), are compact Hausdorff. We show that if (i) the skew category algebra is simple, then (ii) G...

  2. Does Realized Skewness Predict the Cross-Section of Equity Returns?

    DEFF Research Database (Denmark)

    Amaya, Diego; Christoffersen, Peter; Jacobs, Kris

    2015-01-01

    We use intraday data to compute weekly realized moments for equity returns and study their time-series and cross-sectional properties. Buying stocks in the lowest realized skewness decile and selling stocks in the highest realized skewness decile generates an average return of 19 basis points...

  3. Experimental study of the turbulent boundary layer in acceleration-skewed oscillatory flow

    NARCIS (Netherlands)

    van der A, D.A.; O' Donoghue, T.; Davies, A.G; Ribberink, Jan S.

    2011-01-01

    Experiments have been conducted in a large oscillatory flow tunnel to investigate the effects of acceleration skewness on oscillatory boundary layer flow over fixed beds. As well as enabling experimental investigation of the effects of acceleration skewness, the new experiments add substantially to

  4. Likelihood Inference of Nonlinear Models Based on a Class of Flexible Skewed Distributions

    Directory of Open Access Journals (Sweden)

    Xuedong Chen

    2014-01-01

    Full Text Available This paper deals with the issue of the likelihood inference for nonlinear models with a flexible skew-t-normal (FSTN distribution, which is proposed within a general framework of flexible skew-symmetric (FSS distributions by combining with skew-t-normal (STN distribution. In comparison with the common skewed distributions such as skew normal (SN, and skew-t (ST as well as scale mixtures of skew normal (SMSN, the FSTN distribution can accommodate more flexibility and robustness in the presence of skewed, heavy-tailed, especially multimodal outcomes. However, for this distribution, a usual approach of maximum likelihood estimates based on EM algorithm becomes unavailable and an alternative way is to return to the original Newton-Raphson type method. In order to improve the estimation as well as the way for confidence estimation and hypothesis test for the parameters of interest, a modified Newton-Raphson iterative algorithm is presented in this paper, based on profile likelihood for nonlinear regression models with FSTN distribution, and, then, the confidence interval and hypothesis test are also developed. Furthermore, a real example and simulation are conducted to demonstrate the usefulness and the superiority of our approach.

  5. Torque ripple minimization in a doubly salient permanent magnet motors by skewing the rotor teeth

    International Nuclear Information System (INIS)

    Sheth, N.K.; Sekharbabu, A.R.C.; Rajagopal, K.R.

    2006-01-01

    This paper presents the effects of skewing the rotor teeth on the performance of an 8/6 doubly salient permanent magnet motor using a simple method, which utilizes the results obtained from the 2-D FE analysis. The optimum skewing angle is obtained as 12-15 o for the least ripple torque without much reduction in the back-emf

  6. Neoclassical versus Frontier Production Models ? Testing for the Skewness of Regression Residuals

    DEFF Research Database (Denmark)

    Kuosmanen, T; Fosgerau, Mogens

    2009-01-01

    The empirical literature on production and cost functions is divided into two strands. The neoclassical approach concentrates on model parameters, while the frontier approach decomposes the disturbance term to a symmetric noise term and a positively skewed inefficiency term. We propose a theoreti......The empirical literature on production and cost functions is divided into two strands. The neoclassical approach concentrates on model parameters, while the frontier approach decomposes the disturbance term to a symmetric noise term and a positively skewed inefficiency term. We propose...... a theoretical justification for the skewness of the inefficiency term, arguing that this skewness is the key testable hypothesis of the frontier approach. We propose to test the regression residuals for skewness in order to distinguish the two competing approaches. Our test builds directly upon the asymmetry...

  7. Salary adjustments

    CERN Multimedia

    HR Department

    2008-01-01

    In accordance with decisions taken by the Finance Committee and Council in December 2007, salaries are adjusted with effect from 1 January 2008. Scale of basic salaries and scale of stipends paid to fellows (Annex R A 5 and R A 6 respectively): increased by 0.71% with effect from 1 January 2008. As a result of the stability of the Geneva consumer price index, following elements do not increase: a) Family Allowance, Child Allowance and Infant Allowance (Annex R A 3). b) Reimbursement of education fees: maximum amounts of reimbursement (Annex R A 4.01) for the academic year 2007/2008. Related adjustments will be implemented, wherever applicable, to Paid Associates and Students. As in the past, the actual percentage increase of each salary position may vary, due to the application of a constant step value and the rounding effects. Human Resources Department Tel. 73566

  8. Salary adjustments

    CERN Multimedia

    HR Department

    2008-01-01

    In accordance with decisions taken by the Finance Committee and Council in December 2007, salaries are adjusted with effect from 1 January 2008. Scale of basic salaries and scale of stipends paid to fellows (Annex R A 5 and R A 6 respectively): increased by 0.71% with effect from 1 January 2008. As a result of the stability of the Geneva consumer price index, the following elements do not increase: a)\tFamily Allowance, Child Allowance and Infant Allowance (Annex R A 3); b)\tReimbursement of education fees: maximum amounts of reimbursement (Annex R A 4.01) for the academic year 2007/2008. Related adjustments will be applied, wherever applicable, to Paid Associates and Students. As in the past, the actual percentage increase of each salary position may vary, due to the application of a constant step value and rounding effects. Human Resources Department Tel. 73566

  9. Shaft adjuster

    Science.gov (United States)

    Harry, Herbert H.

    1989-01-01

    Apparatus and method for the adjustment and alignment of shafts in high power devices. A plurality of adjacent rotatable angled cylinders are positioned between a base and the shaft to be aligned which when rotated introduce an axial offset. The apparatus is electrically conductive and constructed of a structurally rigid material. The angled cylinders allow the shaft such as the center conductor in a pulse line machine to be offset in any desired alignment position within the range of the apparatus.

  10. Adjustable collimator

    International Nuclear Information System (INIS)

    Carlson, R.W.; Covic, J.; Leininger, G.

    1981-01-01

    In a rotating fan beam tomographic scanner there is included an adjustable collimator and shutter assembly. The assembly includes a fan angle collimation cylinder having a plurality of different length slots through which the beam may pass for adjusting the fan angle of the beam. It also includes a beam thickness cylinder having a plurality of slots of different widths for adjusting the thickness of the beam. Further, some of the slots have filter materials mounted therein so that the operator may select from a plurality of filters. Also disclosed is a servo motor system which allows the operator to select the desired fan angle, beam thickness and filter from a remote location. An additional feature is a failsafe shutter assembly which includes a spring biased shutter cylinder mounted in the collimation cylinders. The servo motor control circuit checks several system conditions before the shutter is rendered openable. Further, the circuit cuts off the radiation if the shutter fails to open or close properly. A still further feature is a reference radiation intensity monitor which includes a tuning-fork shaped light conducting element having a scintillation crystal mounted on each tine. The monitor is placed adjacent the collimator between it and the source with the pair of crystals to either side of the fan beam

  11. Skew category algebras associated with partially defined dynamical systems

    DEFF Research Database (Denmark)

    Lundström, Patrik; Öinert, Per Johan

    2012-01-01

    We introduce partially defined dynamical systems defined on a topological space. To each such system we associate a functor s from a category G to Topop and show that it defines what we call a skew category algebra A ⋊σ G. We study the connection between topological freeness of s and, on the one...... hand, ideal properties of A ⋊σ G and, on the other hand, maximal commutativity of A in A ⋊σ G. In particular, we show that if G is a groupoid and for each e ∈ ob(G) the group of all morphisms e → e is countable and the topological space s(e) is Tychonoff and Baire. Then the following assertions...... are equivalent: (i) s is topologically free; (ii) A has the ideal intersection property, i.e. if I is a nonzero ideal of A ⋊σ G, then I ∩ A ≠ {0}; (iii) the ring A is a maximal abelian complex subalgebra of A ⋊σ G. Thereby, we generalize a result by Svensson, Silvestrov and de Jeu from the additive group...

  12. Skewness and kurtosis analysis for non-Gaussian distributions

    Science.gov (United States)

    Celikoglu, Ahmet; Tirnakli, Ugur

    2018-06-01

    In this paper we address a number of pitfalls regarding the use of kurtosis as a measure of deviations from the Gaussian. We treat kurtosis in both its standard definition and that which arises in q-statistics, namely q-kurtosis. We have recently shown that the relation proposed by Cristelli et al. (2012) between skewness and kurtosis can only be verified for relatively small data sets, independently of the type of statistics chosen; however it fails for sufficiently large data sets, if the fourth moment of the distribution is finite. For infinite fourth moments, kurtosis is not defined as the size of the data set tends to infinity. For distributions with finite fourth moments, the size, N, of the data set for which the standard kurtosis saturates to a fixed value, depends on the deviation of the original distribution from the Gaussian. Nevertheless, using kurtosis as a criterion for deciding which distribution deviates further from the Gaussian can be misleading for small data sets, even for finite fourth moment distributions. Going over to q-statistics, we find that although the value of q-kurtosis is finite in the range of 0 < q < 3, this quantity is not useful for comparing different non-Gaussian distributed data sets, unless the appropriate q value, which truly characterizes the data set of interest, is chosen. Finally, we propose a method to determine the correct q value and thereby to compute the q-kurtosis of q-Gaussian distributed data sets.

  13. Skew redundant MEMS IMU calibration using a Kalman filter

    International Nuclear Information System (INIS)

    Jafari, M; Sahebjameyan, M; Moshiri, B; Najafabadi, T A

    2015-01-01

    In this paper, a novel calibration procedure for skew redundant inertial measurement units (SRIMUs) based on micro-electro mechanical systems (MEMS) is proposed. A general model of the SRIMU measurements is derived which contains the effects of bias, scale factor error and misalignments. For more accuracy, the effect of lever arms of the accelerometers to the center of the table are modeled and compensated in the calibration procedure. Two separate Kalman filters (KFs) are proposed to perform the estimation of error parameters for gyroscopes and accelerometers. The predictive error minimization (PEM) stochastic modeling method is used to simultaneously model the effect of bias instability and random walk noise on the calibration Kalman filters to diminish the biased estimations. The proposed procedure is simulated numerically and has expected experimental results. The calibration maneuvers are applied using a two-axis angle turntable in a way that the persistency of excitation (PE) condition for parameter estimation is met. For this purpose, a trapezoidal calibration profile is utilized to excite different deterministic error parameters of the accelerometers and a pulse profile is used for the gyroscopes. Furthermore, to evaluate the performance of the proposed KF calibration method, a conventional least squares (LS) calibration procedure is derived for the SRIMUs and the simulation and experimental results compare the functionality of the two proposed methods with each other. (paper)

  14. Symmetries and structure of skewed and double distributions

    International Nuclear Information System (INIS)

    Radyushkin, A.V.

    1998-01-01

    Extending the concept of parton densities onto nonforward matrix elements b arO(0,z)vert b arp> of quark and gluon light-cone operators, one can use two types of nonperturbative functions: double distributions (DDs) f(x,α;t), F(x,y;t) and skewed (off and nonforward) parton distributions (SPDs) H(x,ξ;t), F ζ (X,t). The authors treat DDs as primary objects producing SPDs after integration. They emphasize the role of DDs in understanding interplay between (x) and ζ (ξ) dependences of SPDs. In particular, the use of DDs is crucial to secure the polynomiality condition: Nth moments of SPDs are Nth degree polynomials in the relevant skewedness parameter ζ or ξ. They propose simple ansaetze for DDs having correct spectral and symmetry properties and derive model expressions for SPDs satisfying all known constraints. Finally, they argue that for small skewedness, one can obtain SPDs from the usual parton densities by averaging the latter with an appropriate weight over the region [Xminusζ,X] (or [ x minus ξ, x + ξ])

  15. Study on seismic behaviour of integral concrete bridges with different skew angles through fragility curves

    Directory of Open Access Journals (Sweden)

    Mahmoud Reza ُُShiravand

    2017-12-01

    Full Text Available Bridges are key elements in urban transportation system and should be designed to sustain earthquake induced damages to be utilized after earthquake. Extensive damages during last earthquakes highlighted the importance of seismic assessment and damage estimation of bridges. Skewness is one of the primary parameters effects on seismic behavior of bridges. Skew bridges are defined as bridges with skew angle piers and abutments. In these bridges, the piers have some degrees of skewness due to construction restrictions, such as those caused by crossing a waterway, railway line or road. This paper aims to investigate seismic behavior of skew concrete bridges using damage criteria and estimate probability of piers damage with fragility curves. To this end, three types of concrete bridges with two, three and four spans and varying skew angles of 00 ,100, 200 and 300 are modeled with finite element software. Seismic responses of bridge piers under 10 earthquake ground motion records are calculated using incremental dynamic analysis. Following, damage criteria proposed by Mackie and Stojadinovic are used to define damage limits of bridge piers in four damage states of slight, moderate, extensive and complete and bridge fragility curves are developed. The results show that increasing skew angles increases the probability of damage occurrence, particularly in extensive and complete damage states.

  16. Social and genetic structure of paper wasp cofoundress associations: tests of reproductive skew models.

    Science.gov (United States)

    Field, J; Solís, C R; Queller, D C; Strassmann, J E

    1998-06-01

    Recent models postulate that the members of a social group assess their ecological and social environments and agree a "social contract" of reproductive partitioning (skew). We tested social contracts theory by using DNA microsatellites to measure skew in 24 cofoundress associations of paper wasps, Polistes bellicosus. In contrast to theoretical predictions, there was little variation in cofoundress relatedness, and relatedness either did not predict skew or was negatively correlated with it; the dominant/subordinate size ratio, assumed to reflect relative fighting ability, did not predict skew; and high skew was associated with decreased aggression by the rank 2 subordinate toward the dominant. High skew was associated with increased group size. A difficulty with measuring skew in real systems is the frequent changes in group composition that commonly occur in social animals. In P. bellicosus, 61% of egg layers and an unknown number of non-egg layers were absent by the time nests were collected. The social contracts models provide an attractive general framework linking genetics, ecology, and behavior, but there have been few direct tests of their predictions. We question assumptions underlying the models and suggest directions for future research.

  17. Skewness of the cosmic microwave background temperature fluctuations due to the non-linear gravitational instability

    International Nuclear Information System (INIS)

    Munshi, D.; Souradeep, T.; Starobinsky, A.A.

    1995-01-01

    The skewness of the temperature fluctuations of the cosmic microwave background (CMB) produced by initially Gaussian adiabatic perturbations with the flat (Harrison-Zeldovich) spectrum, which arises due to non-linear corrections to a gravitational potential at the matter-dominated stage, is calculated quantitatively. For the standard CDM model, the effect appears to be smaller than expected previously and lies below the cosmic variance limit even for small angles. The sign of the skewness is opposite to that of the skewness of density perturbations. (author)

  18. Report from LHC MD 2171: Amplitude dependent closest tune approach from normal and skew octupoles

    CERN Document Server

    Maclean, Ewen Hamish; Persson, Tobias Hakan Bjorn; Carlier, Felix Simon; CERN. Geneva. ATS Department

    2018-01-01

    Simulation-based studies predict significant amplitude-dependent closest tune approach can be generated by skew octupole sources in conjunction with their normal octupolar counterparts. This has the potential to significantly influence Landau damping at small β∗, where skew octupole errors in the experimental IRs, together with b4 introduced by the Landau octupoles, is predicted to cause large distortion of the tune footprint. This MD aimed to perform a first exploration of these predictions with beam, by enhancing skew octupole sources in the IRs at injection and measuring amplitude detuning with free kicks in the plane approaching the coupling resonance.

  19. Coalescent Processes with Skewed Offspring Distributions and Nonequilibrium Demography.

    Science.gov (United States)

    Matuszewski, Sebastian; Hildebrandt, Marcel E; Achaz, Guillaume; Jensen, Jeffrey D

    2018-01-01

    Nonequilibrium demography impacts coalescent genealogies leaving detectable, well-studied signatures of variation. However, similar genomic footprints are also expected under models of large reproductive skew, posing a serious problem when trying to make inference. Furthermore, current approaches consider only one of the two processes at a time, neglecting any genomic signal that could arise from their simultaneous effects, preventing the possibility of jointly inferring parameters relating to both offspring distribution and population history. Here, we develop an extended Moran model with exponential population growth, and demonstrate that the underlying ancestral process converges to a time-inhomogeneous psi-coalescent. However, by applying a nonlinear change of time scale-analogous to the Kingman coalescent-we find that the ancestral process can be rescaled to its time-homogeneous analog, allowing the process to be simulated quickly and efficiently. Furthermore, we derive analytical expressions for the expected site-frequency spectrum under the time-inhomogeneous psi-coalescent, and develop an approximate-likelihood framework for the joint estimation of the coalescent and growth parameters. By means of extensive simulation, we demonstrate that both can be estimated accurately from whole-genome data. In addition, not accounting for demography can lead to serious biases in the inferred coalescent model, with broad implications for genomic studies ranging from ecology to conservation biology. Finally, we use our method to analyze sequence data from Japanese sardine populations, and find evidence of high variation in individual reproductive success, but few signs of a recent demographic expansion. Copyright © 2018 by the Genetics Society of America.

  20. Investigation of free vibration characteristics for skew multiphase magneto-electro-elastic plate

    Science.gov (United States)

    Kiran, M. C.; Kattimani, S.

    2018-04-01

    This article presents the investigation of skew multiphase magneto-electro-elastic (MMEE) plate to assess its free vibration characteristics. A finite element (FE) model is formulated considering the different couplings involved via coupled constitutive equations. The transformation matrices are derived to transform local degrees of freedom into the global degrees of freedom for the nodes lying on the skew edges. Effect of different volume fraction (Vf) on the free vibration behavior is explicitly studied. In addition, influence of width to thickness ratio, the aspect ratio, and the stacking arrangement on natural frequencies of skew multiphase MEE plate investigated. Particular attention has been paid to investigate the effect of skew angle on the non-dimensional Eigen frequencies of multiphase MEE plate with simply supported edges.

  1. On nomenclature for, and the relative merits of, two formulations of skew distributions

    KAUST Repository

    Azzalini, Adelchi

    2015-12-21

    We examine some skew distributions used extensively within the model-based clustering literature in recent years, paying special attention to claims that have been made about their relative efficacy. Theoretical arguments are provided as well as real data examples.

  2. Forces in wingwalls from thermal expansion of skewed semi-integral bridges.

    Science.gov (United States)

    2010-11-01

    Jointless bridges, such as semi-integral and integral bridges, have become more popular in recent years because of their simplicity in the construction and the elimination of high costs related to joint maintenance. Prior research has shown that skew...

  3. INVESTIGATION OF SEISMIC PERFORMANCE AND DESIGN OF TYPICAL CURVED AND SKEWED BRIDGES IN COLORADO

    Science.gov (United States)

    2018-01-15

    This report summarizes the analytical studies on the seismic performance of typical Colorado concrete bridges, particularly those with curved and skewed configurations. A set of bridge models with different geometric configurations derived from a pro...

  4. On nomenclature for, and the relative merits of, two formulations of skew distributions

    KAUST Repository

    Azzalini, Adelchi; Browne, Ryan P.; Genton, Marc G.; McNicholas, Paul D.

    2015-01-01

    We examine some skew distributions used extensively within the model-based clustering literature in recent years, paying special attention to claims that have been made about their relative efficacy. Theoretical arguments are provided as well as real data examples.

  5. Geometric representation of the mean-variance-skewness portfolio frontier based upon the shortage function

    OpenAIRE

    Kerstens, Kristiaan; Mounier, Amine; Van de Woestyne, Ignace

    2008-01-01

    The literature suggests that investors prefer portfolios based on mean, variance and skewness rather than portfolios based on mean-variance (MV) criteria solely. Furthermore, a small variety of methods have been proposed to determine mean-variance-skewness (MVS) optimal portfolios. Recently, the shortage function has been introduced as a measure of efficiency, allowing to characterize MVS optimalportfolios using non-parametric mathematical programming tools. While tracing the MV portfolio fro...

  6. Normalization of High Dimensional Genomics Data Where the Distribution of the Altered Variables Is Skewed

    Science.gov (United States)

    Landfors, Mattias; Philip, Philge; Rydén, Patrik; Stenberg, Per

    2011-01-01

    Genome-wide analysis of gene expression or protein binding patterns using different array or sequencing based technologies is now routinely performed to compare different populations, such as treatment and reference groups. It is often necessary to normalize the data obtained to remove technical variation introduced in the course of conducting experimental work, but standard normalization techniques are not capable of eliminating technical bias in cases where the distribution of the truly altered variables is skewed, i.e. when a large fraction of the variables are either positively or negatively affected by the treatment. However, several experiments are likely to generate such skewed distributions, including ChIP-chip experiments for the study of chromatin, gene expression experiments for the study of apoptosis, and SNP-studies of copy number variation in normal and tumour tissues. A preliminary study using spike-in array data established that the capacity of an experiment to identify altered variables and generate unbiased estimates of the fold change decreases as the fraction of altered variables and the skewness increases. We propose the following work-flow for analyzing high-dimensional experiments with regions of altered variables: (1) Pre-process raw data using one of the standard normalization techniques. (2) Investigate if the distribution of the altered variables is skewed. (3) If the distribution is not believed to be skewed, no additional normalization is needed. Otherwise, re-normalize the data using a novel HMM-assisted normalization procedure. (4) Perform downstream analysis. Here, ChIP-chip data and simulated data were used to evaluate the performance of the work-flow. It was found that skewed distributions can be detected by using the novel DSE-test (Detection of Skewed Experiments). Furthermore, applying the HMM-assisted normalization to experiments where the distribution of the truly altered variables is skewed results in considerably higher

  7. The effect of forward skewed rotor blades on aerodynamic and aeroacoustic performance of axial-flow fan

    Science.gov (United States)

    Wei, Jun; Zhong, Fangyuan

    Based on comparative experiment, this paper deals with using tangentially skewed rotor blades in axial-flow fan. It is seen from the comparison of the overall performance of the fan with skewed bladed rotor and radial bladed rotor that the skewed blades operate more efficiently than the radial blades, especially at low volume flows. Meanwhile, decrease in pressure rise and flow rate of axial-flow fan with skewed rotor blades is found. The rotor-stator interaction noise and broadband noise of axial-flow fan are reduced with skewed rotor blades. Forward skewed blades tend to reduce the accumulation of the blade boundary layer in the tip region resulting from the effect of centrifugal forces. The turning of streamlines from the outer radius region into inner radius region in blade passages due to the radial component of blade forces of skewed blades is the main reason for the decrease in pressure rise and flow rate.

  8. A Multi-Resolution Spatial Model for Large Datasets Based on the Skew-t Distribution

    KAUST Repository

    Tagle, Felipe

    2017-12-06

    Large, non-Gaussian spatial datasets pose a considerable modeling challenge as the dependence structure implied by the model needs to be captured at different scales, while retaining feasible inference. Skew-normal and skew-t distributions have only recently begun to appear in the spatial statistics literature, without much consideration, however, for the ability to capture dependence at multiple resolutions, and simultaneously achieve feasible inference for increasingly large data sets. This article presents the first multi-resolution spatial model inspired by the skew-t distribution, where a large-scale effect follows a multivariate normal distribution and the fine-scale effects follow a multivariate skew-normal distributions. The resulting marginal distribution for each region is skew-t, thereby allowing for greater flexibility in capturing skewness and heavy tails characterizing many environmental datasets. Likelihood-based inference is performed using a Monte Carlo EM algorithm. The model is applied as a stochastic generator of daily wind speeds over Saudi Arabia.

  9. Analysis of domain wall dynamics based on skewness of magnetic Barkhausen noise for applied stress determination

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Song [College of Electrical Engineering and Control Science, Nanjing Tech University, Nanjing, Jiangsu 211816 (China); School of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China); Tian, GuiYun, E-mail: tian280@hotmail.com [School of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China); School of Electrical and Electronic Engineering, Merz Court, University of Newcastle upon Tyne, Newcastle NE1 7RU (United Kingdom); Dobmann, Gerd; Wang, Ping [School of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China)

    2017-01-01

    Skewness of Magnetic Barkhausen Noise (MBN) signal is used as a new feature for applied stress determination. After experimental studies, skewness presents its ability for measuring applied tensile stress compared with conventional feature, meanwhile, a non-linear behavior of this new feature and an independence of the excitation conditions under compressive stress are found and discussed. Effective damping during domain wall motion influencing the asymmetric shape of the MBN statistical distribution function is discussed under compressive and tensile stress variation. Domain wall (DW) energy and distance between pinning edges of the DW are considered altering the characteristic relaxation time, which is the reason for the non-linear phenomenon of skewness. - Highlights: • The skewness of magnetic Barkhausen noise profile is proposed as a new feature for applied stress determination. • The skewness is sensitive to applied stress and independent to excitation frequency. • Domain wall energy and pinning distance influence the relaxation time of domain wall, which leads to a non-linear behavior of skewness under compressive stress.

  10. Audit of Provisions and Value Adjustments – a Very Important Objective for the Assessment of Information Comprised in the Financial Statements

    Directory of Open Access Journals (Sweden)

    Cristina IOVU

    2017-04-01

    Full Text Available Any type of entity must show in its financial statements information regarding its significant estimations concerning the future periods and other important sources of uncertainty at the date at which the financial statements are drafted, which presents an increased risk of generating an adjustment of the accounting value of the assets and debts in the future fiscal year. This information must include the nature of the estimations and their accounting value at the date of the balance sheet. The auditing of the financial statements in which accounting estimations are presented frame a high risk of significant distortion. Because of this, the auditor must obtain sufficient audit evidence which would certify if these estimations are reasonable, respectively if the data on which the estimations are based upon are accurate, complete and relevant, and the procedures and methods used for the development of the estimations are adequate for the balance sheet structures to which they apply. The development of provisions, as a manner to reflect uncertainties within the accounting system, contributes to the accurate representation of the company’s financial position. Such uncertainties are acknowledged through the presentation of their nature and value, but also through the exercising of prudence for the development of the financial statements. Prudence implies the identification of those accounting estimations, associated to the given uncertainties conditions, which would not over-evaluate the assets and the incomes, and the debts and expenses would not be under-evaluated. Exercising prudence should not allow, for instance, the accumulation of excessive provisions, the deliberate under-evaluation of assets and incomes, nor the deliberate over-evaluation of debts or expenses. This requirement is imperative, due to the fact that investors substantiate their economic decisions starting from the analysis of the financial statements, as accurate image of the

  11. Forecasting with Option-Implied Information

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Chang, Bo Young

    2013-01-01

    This chapter surveys the methods available for extracting information from option prices that can be used in forecasting. We consider option-implied volatilities, skewness, kurtosis, and densities. More generally, we discuss how any forecasting object that is a twice differentiable function...... of the future realization of the underlying risky asset price can utilize option-implied information in a well-defined manner. Going beyond the univariate option-implied density, we also consider results on option-implied covariance, correlation and beta forecasting, as well as the use of option......-implied information in cross-sectional forecasting of equity returns. We discuss how option-implied information can be adjusted for risk premia to remove biases in forecasting regressions....

  12. Bayesian linear regression with skew-symmetric error distributions with applications to survival analysis

    KAUST Repository

    Rubio, Francisco J.

    2016-02-09

    We study Bayesian linear regression models with skew-symmetric scale mixtures of normal error distributions. These kinds of models can be used to capture departures from the usual assumption of normality of the errors in terms of heavy tails and asymmetry. We propose a general noninformative prior structure for these regression models and show that the corresponding posterior distribution is proper under mild conditions. We extend these propriety results to cases where the response variables are censored. The latter scenario is of interest in the context of accelerated failure time models, which are relevant in survival analysis. We present a simulation study that demonstrates good frequentist properties of the posterior credible intervals associated with the proposed priors. This study also sheds some light on the trade-off between increased model flexibility and the risk of over-fitting. We illustrate the performance of the proposed models with real data. Although we focus on models with univariate response variables, we also present some extensions to the multivariate case in the Supporting Information.

  13. A Skew-t space-varying regression model for the spectral analysis of resting state brain activity.

    Science.gov (United States)

    Ismail, Salimah; Sun, Wenqi; Nathoo, Farouk S; Babul, Arif; Moiseev, Alexader; Beg, Mirza Faisal; Virji-Babul, Naznin

    2013-08-01

    It is known that in many neurological disorders such as Down syndrome, main brain rhythms shift their frequencies slightly, and characterizing the spatial distribution of these shifts is of interest. This article reports on the development of a Skew-t mixed model for the spatial analysis of resting state brain activity in healthy controls and individuals with Down syndrome. Time series of oscillatory brain activity are recorded using magnetoencephalography, and spectral summaries are examined at multiple sensor locations across the scalp. We focus on the mean frequency of the power spectral density, and use space-varying regression to examine associations with age, gender and Down syndrome across several scalp regions. Spatial smoothing priors are incorporated based on a multivariate Markov random field, and the markedly non-Gaussian nature of the spectral response variable is accommodated by the use of a Skew-t distribution. A range of models representing different assumptions on the association structure and response distribution are examined, and we conduct model selection using the deviance information criterion. (1) Our analysis suggests region-specific differences between healthy controls and individuals with Down syndrome, particularly in the left and right temporal regions, and produces smoothed maps indicating the scalp topography of the estimated differences.

  14. Sample size calculations based on a difference in medians for positively skewed outcomes in health care studies

    Directory of Open Access Journals (Sweden)

    Aidan G. O’Keeffe

    2017-12-01

    Full Text Available Abstract Background In healthcare research, outcomes with skewed probability distributions are common. Sample size calculations for such outcomes are typically based on estimates on a transformed scale (e.g. log which may sometimes be difficult to obtain. In contrast, estimates of median and variance on the untransformed scale are generally easier to pre-specify. The aim of this paper is to describe how to calculate a sample size for a two group comparison of interest based on median and untransformed variance estimates for log-normal outcome data. Methods A log-normal distribution for outcome data is assumed and a sample size calculation approach for a two-sample t-test that compares log-transformed outcome data is demonstrated where the change of interest is specified as difference in median values on the untransformed scale. A simulation study is used to compare the method with a non-parametric alternative (Mann-Whitney U test in a variety of scenarios and the method is applied to a real example in neurosurgery. Results The method attained a nominal power value in simulation studies and was favourable in comparison to a Mann-Whitney U test and a two-sample t-test of untransformed outcomes. In addition, the method can be adjusted and used in some situations where the outcome distribution is not strictly log-normal. Conclusions We recommend the use of this sample size calculation approach for outcome data that are expected to be positively skewed and where a two group comparison on a log-transformed scale is planned. An advantage of this method over usual calculations based on estimates on the log-transformed scale is that it allows clinical efficacy to be specified as a difference in medians and requires a variance estimate on the untransformed scale. Such estimates are often easier to obtain and more interpretable than those for log-transformed outcomes.

  15. Characteristic function-based semiparametric inference for skew-symmetric models

    KAUST Repository

    Potgieter, Cornelis J.

    2012-12-26

    Skew-symmetric models offer a very flexible class of distributions for modelling data. These distributions can also be viewed as selection models for the symmetric component of the specified skew-symmetric distribution. The estimation of the location and scale parameters corresponding to the symmetric component is considered here, with the symmetric component known. Emphasis is placed on using the empirical characteristic function to estimate these parameters. This is made possible by an invariance property of the skew-symmetric family of distributions, namely that even transformations of random variables that are skew-symmetric have a distribution only depending on the symmetric density. A distance metric between the real components of the empirical and true characteristic functions is minimized to obtain the estimators. The method is semiparametric, in that the symmetric component is specified, but the skewing function is assumed unknown. Furthermore, the methodology is extended to hypothesis testing. Two tests for a hypothesis of specific parameter values are considered, as well as a test for the hypothesis that the symmetric component has a specific parametric form. A resampling algorithm is described for practical implementation of these tests. The outcomes of various numerical experiments are presented. © 2012 Board of the Foundation of the Scandinavian Journal of Statistics.

  16. Generalized Skew Coefficients of Annual Peak Flows for Rural, Unregulated Streams in West Virginia

    Science.gov (United States)

    Atkins, John T.; Wiley, Jeffrey B.; Paybins, Katherine S.

    2009-01-01

    Generalized skew was determined from analysis of records from 147 streamflow-gaging stations in or near West Virginia. The analysis followed guidelines established by the Interagency Advisory Committee on Water Data described in Bulletin 17B, except that stations having 50 or more years of record were used instead of stations with the less restrictive recommendation of 25 or more years of record. The generalized-skew analysis included contouring, averaging, and regression of station skews. The best method was considered the one with the smallest mean square error (MSE). MSE is defined as the following quantity summed and divided by the number of peaks: the square of the difference of an individual logarithm (base 10) of peak flow less the mean of all individual logarithms of peak flow. Contouring of station skews was the best method for determining generalized skew for West Virginia, with a MSE of about 0.2174. This MSE is an improvement over the MSE of about 0.3025 for the national map presented in Bulletin 17B.

  17. Study and optimal correction of a systematic skew quadrupole field in the Tevatron

    International Nuclear Information System (INIS)

    Snopok, Pavel; Johnstone, Carol; Berz, Martin; Ovsyannikov, Dmitry A.; Ovsyannikov, Alexander D.

    2006-01-01

    Increasing demands for luminosity in existing and future colliders have made lattice design and error tolerance and correction critical to achieving performance goals. The current state of the Tevatron collider is an example, with a strong skew quadrupole error present in the operational lattice. This work studies the high-order performance of the Tevatron and the strong nonlinear behavior introduced when a significant skew quadrupole error is combined with conventional sextupole correction, a behavior still clearly evident after optimal tuning of available skew quadrupole circuits. An optimization study is performed using different skew quadrupole families, and, importantly, local and global correction of the linear skew terms in maps generated by the code COSY INFINITY [M. Berz, COSY INFINITY version 8.1 user's guide and reference manual, Department of Physics and Astronomy MSUHEP-20704, Michigan State University (2002). URL http://cosy.pa.msu.edu/cosymanu/index.html]. Two correction schemes with one family locally correcting each arc and eight independent correctors in the straight sections for global correction are proposed and shown to dramatically improve linearity and performance of the baseline Tevatron lattice

  18. Handling Data Skew in MapReduce Cluster by Using Partition Tuning

    Directory of Open Access Journals (Sweden)

    Yufei Gao

    2017-01-01

    Full Text Available The healthcare industry has generated large amounts of data, and analyzing these has emerged as an important problem in recent years. The MapReduce programming model has been successfully used for big data analytics. However, data skew invariably occurs in big data analytics and seriously affects efficiency. To overcome the data skew problem in MapReduce, we have in the past proposed a data processing algorithm called Partition Tuning-based Skew Handling (PTSH. In comparison with the one-stage partitioning strategy used in the traditional MapReduce model, PTSH uses a two-stage strategy and the partition tuning method to disperse key-value pairs in virtual partitions and recombines each partition in case of data skew. The robustness and efficiency of the proposed algorithm were tested on a wide variety of simulated datasets and real healthcare datasets. The results showed that PTSH algorithm can handle data skew in MapReduce efficiently and improve the performance of MapReduce jobs in comparison with the native Hadoop, Closer, and locality-aware and fairness-aware key partitioning (LEEN. We also found that the time needed for rule extraction can be reduced significantly by adopting the PTSH algorithm, since it is more suitable for association rule mining (ARM on healthcare data.

  19. Univariate and multivariate skewness and kurtosis for measuring nonnormality: Prevalence, influence and estimation.

    Science.gov (United States)

    Cain, Meghan K; Zhang, Zhiyong; Yuan, Ke-Hai

    2017-10-01

    Nonnormality of univariate data has been extensively examined previously (Blanca et al., Methodology: European Journal of Research Methods for the Behavioral and Social Sciences, 9(2), 78-84, 2013; Miceeri, Psychological Bulletin, 105(1), 156, 1989). However, less is known of the potential nonnormality of multivariate data although multivariate analysis is commonly used in psychological and educational research. Using univariate and multivariate skewness and kurtosis as measures of nonnormality, this study examined 1,567 univariate distriubtions and 254 multivariate distributions collected from authors of articles published in Psychological Science and the American Education Research Journal. We found that 74 % of univariate distributions and 68 % multivariate distributions deviated from normal distributions. In a simulation study using typical values of skewness and kurtosis that we collected, we found that the resulting type I error rates were 17 % in a t-test and 30 % in a factor analysis under some conditions. Hence, we argue that it is time to routinely report skewness and kurtosis along with other summary statistics such as means and variances. To facilitate future report of skewness and kurtosis, we provide a tutorial on how to compute univariate and multivariate skewness and kurtosis by SAS, SPSS, R and a newly developed Web application.

  20. Generation of net sediment transport by velocity skewness in oscillatory sheet flow

    Science.gov (United States)

    Chen, Xin; Li, Yong; Chen, Genfa; Wang, Fujun; Tang, Xuelin

    2018-01-01

    This study utilizes a qualitative approach and a two-phase numerical model to investigate net sediment transport caused by velocity skewness beneath oscillatory sheet flow and current. The qualitative approach is derived based on the pseudo-laminar approximation of boundary layer velocity and exponential approximation of concentration. The two-phase model can obtain well the instantaneous erosion depth, sediment flux, boundary layer thickness, and sediment transport rate. It can especially illustrate the difference between positive and negative flow stages caused by velocity skewness, which is considerably important in determining the net boundary layer flow and sediment transport direction. The two-phase model also explains the effect of sediment diameter and phase-lag to sediment transport by comparing the instantaneous-type formulas to better illustrate velocity skewness effect. In previous studies about sheet flow transport in pure velocity-skewed flows, net sediment transport is only attributed to the phase-lag effect. In the present study with the qualitative approach and two-phase model, phase-lag effect is shown important but not sufficient for the net sediment transport beneath pure velocity-skewed flow and current, while the asymmetric wave boundary layer development between positive and negative flow stages also contributes to the sediment transport.

  1. Finding the Right Distribution for Highly Skewed Zero-inflated Clinical Data

    Directory of Open Access Journals (Sweden)

    Resmi Gupta

    2013-03-01

    Full Text Available Discrete, highly skewed distributions with excess numbers of zeros often result in biased estimates and misleading inferences if the zeros are not properly addressed. A clinical example of children with electrophysiologic disorders in which many of the children are treated without surgery is provided. The purpose of the current study was to identify the optimal modeling strategy for highly skewed, zeroinflated data often observed in the clinical setting by: (a simulating skewed, zero-inflated count data; (b fitting simulated data with Poisson, Negative Binomial, Zero-Inflated Poisson (ZIP and Zero-inflated Negative Binomial (ZINB models; and, (c applying the aforementioned models to actual, highlyskewed, clinical data of children with an EP disorder. The ZIP model was observed to be the optimal model based on traditional fit statistics as well as estimates of bias, mean-squared error, and coverage.  

  2. A Cable-Passive Damper System for Sway and Skew Motion Control of a Crane Spreader

    Directory of Open Access Journals (Sweden)

    La Duc Viet

    2015-01-01

    Full Text Available While the crane control problem is often approached by applying a certain active control command to some parts of the crane, this paper proposes a cable-passive damper system to reduce the vibration of a four-cable suspended crane spreader. The residual sway and skew motions of a crane spreader always produce the angle deflections between the crane cables and the crane spreader. The idea in this paper is to convert those deflections into energy dissipated by the viscous dampers, which connect the cables and the spreader. The proposed damper system is effective in reducing spreader sway and skew motions. Moreover, the optimal damping coefficient can be found analytically by minimizing the time integral of system energy. The numerical simulations show that the proposed passive system can assist the input shaping control of the trolley motion in reducing both sway and skew responses.

  3. Determinants of (–1,1-matrices of the skew-symmetric type: a cocyclic approach

    Directory of Open Access Journals (Sweden)

    Álvarez Víctor

    2015-01-01

    Full Text Available An n by n skew-symmetric type (-1; 1-matrix K =[ki;j ] has 1’s on the main diagonal and ±1’s elsewhere with ki;j =-kj;i . The largest possible determinant of such a matrix K is an interesting problem. The literature is extensive for n ≡ 0 mod 4 (skew-Hadamard matrices, but for n ≡ 2 mod 4 there are few results known for this question. In this paper we approach this problem constructing cocyclic matrices over the dihedral group of 2t elements, for t odd, which are equivalent to (-1; 1-matrices of skew type. Some explicit calculations have been done up to t =11. To our knowledge, the upper bounds on the maximal determinant in orders 18 and 22 have been improved.

  4. Skewed Normal Distribution Of Return Assets In Call European Option Pricing

    Directory of Open Access Journals (Sweden)

    Evy Sulistianingsih

    2011-12-01

    Full Text Available Option is one of security derivates. In financial market, option is a contract that gives a right (notthe obligation for its owner to buy or sell a particular asset for a certain price at a certain time.Option can give a guarantee for a risk that can be faced in a market.This paper studies about theuse of Skewed Normal Distribution (SN in call europeanoption pricing. The SN provides aflexible framework that captures the skewness of log return. We obtain aclosed form solution forthe european call option pricing when log return follow the SN. Then, we will compare optionprices that is obtained by the SN and the Black-Scholes model with the option prices of market. Keywords: skewed normaldistribution, log return, options.

  5. Option-Based Estimation of the Price of Co-Skewness and Co-Kurtosis Risk

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Fournier, Mathieu; Fournier, Mathieu

    -neutral second moments, and the price of co-kurtosis risk corresponds to the spread between the physical and the risk-neutral third moments. The option-based estimates of the prices of risk lead to reasonable values of the associated risk premia. An out-of-sample analysis of factor models with co-skewness and co......We show that the prices of risk for factors that are nonlinear in the market return are readily obtained using index option prices. We apply this insight to the price of co-skewness and co-kurtosis risk. The price of co-skewness risk corresponds to the spread between the physical and the risk......-kurtosis risk indicates that the new estimates of the price of risk improve the models performance. Models with higher-order market moments also robustly outperform standard competitors such as the CAPM and the Fama-French model....

  6. Option-Based Estimation of the Price of Co-Skewness and Co-Kurtosis Risk

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Fournier, Mathieu; Jacobs, Kris

    -neutral second moments, and the price of co-kurtosis risk corresponds to the spread between the physical and the risk-neutral third moments. The option-based estimates of the prices of risk lead to reasonable values of the associated risk premia. An out-of-sample analysis of factor models with co-skewness and co......We show that the prices of risk for factors that are nonlinear in the market return are readily obtained using index option prices. We apply this insight to the price of co-skewness and co-kurtosis risk. The price of co-skewness risk corresponds to the spread between the physical and the risk......-kurtosis risk indicates that the new estimates of the price of risk improve the models' performance. Models with higher-order market moments also robustly outperform standard competitors such as the CAPM and the Fama-French model....

  7. Deterioration of the Skew Quadrupole Moment in Tevatron Dipoles Over Time

    CERN Document Server

    Syphers, Michael J

    2005-01-01

    During the 20 years since it was first commissioned, the Fermilab Tevatron has developed strong coupling between the two transverse degrees of freedom. A circuit of skew quadrupole magnets is used to correct for coupling and, though capable, its required strength has increased since 1983 by more than an order of magnitude. In more recent years changes to the Tevatron for colliding beams operation have altered the skew quadrupole corrector distribution and strong local coupling become evident, often encumbering routine operation during the present physics run. Detailed magnet measurements were performed on each individual magnet during construction, and in early 2003 it was realized that measurements could be performed on the magnets in situ which could determine coil movements within the iron yoke since the early 1980's. It was discovered that the superconducting coils had become vertically displaced relative to their yokes since their construction. The ensuing systematic skew quadrupole field introduced by t...

  8. T helper cell 2 immune skewing in pregnancy/early life

    DEFF Research Database (Denmark)

    McFadden, J P; Thyssen, J P; Basketter, D A

    2015-01-01

    During the last 50 years there has been a significant increase in Western societies of atopic disease and associated allergy. The balance between functional subpopulations of T helper cells (Th) determines the quality of the immune response provoked by antigen. One such subpopulation - Th2 cells...... that in Westernized societies reduced exposure during early childhood to pathogenic microorganisms favours the development of atopic allergy. Pregnancy is normally associated with Th2 skewing, which persists for some months in the neonate before Th1/Th2 realignment occurs. In this review, we consider...... the immunophysiology of Th2 immune skewing during pregnancy. In particular, we explore the possibility that altered and increased patterns of exposure to certain chemicals have served to accentuate this normal Th2 skewing and therefore further promote the persistence of a Th2 bias in neonates. Furthermore, we propose...

  9. PS-Modules over Ore Extensions and Skew Generalized Power Series Rings

    Directory of Open Access Journals (Sweden)

    Refaat M. Salem

    2015-01-01

    Full Text Available A right R-module MR is called a PS-module if its socle, SocMR, is projective. We investigate PS-modules over Ore extension and skew generalized power series extension. Let R be an associative ring with identity, MR a unitary right R-module, O=Rx;α,δ Ore extension, MxO a right O-module, S,≤ a strictly ordered additive monoid, ω:S→EndR a monoid homomorphism, A=RS,≤,ω the skew generalized power series ring, and BA=MS,≤RS,≤, ω the skew generalized power series module. Then, under some certain conditions, we prove the following: (1 If MR is a right PS-module, then MxO is a right PS-module. (2 If MR is a right PS-module, then BA is a right PS-module.

  10. Skew harmonics suppression in electromagnets with application to the Advanced Light Source (ALS) storage ring corrector magnet design

    International Nuclear Information System (INIS)

    Schlueter, R.; Halbach, K.

    1993-09-01

    An analytical expression for prediction of skew harmonics in an iron core combined function regular/skew dipole magnet due to arbitrarily positioned electromagnet coils is developed. A structured approach is presented for the suppression of an arbitrary number of harmonic components to arbitrarily low values. Application of the analytical harmonic strength calculations coupled to the structured harmonic suppression approach is presented in the context of the design of the ALS storage ring corrector magnets, where quadrupole, sextupole, and octupole skew harmonics were reduced to less than 1.0% of the skew dipole at the beam aperture radius r = 3.0 cm

  11. Differential models of twin correlations in skew for body-mass index (BMI).

    Science.gov (United States)

    Tsang, Siny; Duncan, Glen E; Dinescu, Diana; Turkheimer, Eric

    2018-01-01

    Body Mass Index (BMI), like most human phenotypes, is substantially heritable. However, BMI is not normally distributed; the skew appears to be structural, and increases as a function of age. Moreover, twin correlations for BMI commonly violate the assumptions of the most common variety of the classical twin model, with the MZ twin correlation greater than twice the DZ correlation. This study aimed to decompose twin correlations for BMI using more general skew-t distributions. Same sex MZ and DZ twin pairs (N = 7,086) from the community-based Washington State Twin Registry were included. We used latent profile analysis (LPA) to decompose twin correlations for BMI into multiple mixture distributions. LPA was performed using the default normal mixture distribution and the skew-t mixture distribution. Similar analyses were performed for height as a comparison. Our analyses are then replicated in an independent dataset. A two-class solution under the skew-t mixture distribution fits the BMI distribution for both genders. The first class consists of a relatively normally distributed, highly heritable BMI with a mean in the normal range. The second class is a positively skewed BMI in the overweight and obese range, with lower twin correlations. In contrast, height is normally distributed, highly heritable, and is well-fit by a single latent class. Results in the replication dataset were highly similar. Our findings suggest that two distinct processes underlie the skew of the BMI distribution. The contrast between height and weight is in accord with subjective psychological experience: both are under obvious genetic influence, but BMI is also subject to behavioral control, whereas height is not.

  12. Elevated mortality among birds in Chernobyl as judged from skewed age and sex ratios.

    Directory of Open Access Journals (Sweden)

    Anders Pape Møller

    Full Text Available Radiation has negative effects on survival of animals including humans, although the generality of this claim is poorly documented under low-dose field conditions. Because females may suffer disproportionately from the effects of radiation on survival due to differences in sex roles during reproduction, radiation-induced mortality may result in male-skewed adult sex ratios.We estimated the effects of low-dose radiation on adult survival rates in birds by determining age ratios of adults captured in mist nets during the breeding season in relation to background radiation levels around Chernobyl and in nearby uncontaminated control areas. Age ratios were skewed towards yearlings, especially in the most contaminated areas, implying that adult survival rates were reduced in contaminated areas, and that populations in such areas could only be maintained through immigration from nearby uncontaminated areas. Differential mortality in females resulted in a strongly male-skewed sex ratio in the most contaminated areas. In addition, males sang disproportionately commonly in the most contaminated areas where the sex ratio was male skewed presumably because males had difficulty finding and acquiring mates when females were rare. The results were not caused by permanent emigration by females from the most contaminated areas because none of the recaptured birds had changed breeding site, and the proportion of individuals with morphological abnormalities did not differ significantly between the sexes for areas with normal and higher levels of contamination.These findings are consistent with the hypothesis that the adult survival rate of female birds is particularly susceptible to the effects of low-dose radiation, resulting in male skewed sex ratios at high levels of radiation. Such skewed age ratios towards yearlings in contaminated areas are consistent with the hypothesis that an area exceeding 30,000 km(2 in Chernobyl's surroundings constitutes an

  13. Some homological properties of skew PBW extensions arising in non-commutative algebraic geometry

    Directory of Open Access Journals (Sweden)

    Lezama Oswaldo

    2017-06-01

    Full Text Available In this short paper we study for the skew PBW (Poincar-Birkhoff-Witt extensions some homological properties arising in non-commutative algebraic geometry, namely, Auslander-Gorenstein regularity, Cohen-Macaulayness and strongly noetherianity. Skew PBW extensions include a considerable number of non-commutative rings of polynomial type such that classical PBW extensions, quantum polynomial rings, multiplicative analogue of the Weyl algebra, some Sklyanin algebras, operator algebras, diffusion algebras, quadratic algebras in 3 variables, among many others. Parametrization of the point modules of some examples is also presented.

  14. Widely Linear Equalization for IQ Imbalance and Skew Compensation in Optical Coherent Receivers

    DEFF Research Database (Denmark)

    Porto da Silva, Edson; Zibar, Darko

    2016-01-01

    In this paper, an alternative approach to design linear equalization algorithms for optical coherent receivers is introduced. Using widely linear complex analysis, a general analytical model it is shown, where In-phase/quadrature (IQ) imbalances and IQ skew at the coherent receiver front-end are ......In this paper, an alternative approach to design linear equalization algorithms for optical coherent receivers is introduced. Using widely linear complex analysis, a general analytical model it is shown, where In-phase/quadrature (IQ) imbalances and IQ skew at the coherent receiver front...

  15. Measurement of the width and skewness of elliptic flow fluctuations in PbPb collisions at 5.02 TeV with CMS

    CERN Document Server

    Castle, James Robert

    2017-01-01

    Flow harmonic fluctuations are studied for PbPb collisions at $\\sqrt{s_{NN}} = 5.02~\\mathrm{TeV}$ using the CMS detector at the LHC. Flow harmonic probability distributions $p\\left(v_2\\right)$ are obtained by unfolding smearing effects from observed azimuthal anisotropy distributions using particles of $0.3 < p_{\\mathrm{T}} < 3.0~\\mathrm{GeV}/c$ and $\\lvert \\eta \\rvert < 1.0$. Cumulant flow harmonics are determined from the moments of $p\\left(v_2\\right)$ and used to estimate the standardized elliptic flow skewness. Hydrodynamic models predict this skewness to be negative with respect to the reaction plane. A statistically significant negative skewness is observed for all centrality bins as evidenced by a splitting between $v_2$ $\\{{4}\\}$, $v_2$ $\\{{6}\\}$, and $v_2$ $\\{{8}\\}$ cumulants. Elliptic power law distribution fits are made to $p\\left(v_2\\right)$ distributions to infer information on the nature of initial-state eccentricity distributions and found to provide a more accurate description of the ...

  16. Large-scale genomic 2D visualization reveals extensive CG-AT skew correlation in bird genomes

    Directory of Open Access Journals (Sweden)

    Deng Xuemei

    2007-11-01

    Full Text Available Abstract Background Bird genomes have very different compositional structure compared with other warm-blooded animals. The variation in the base skew rules in the vertebrate genomes remains puzzling, but it must relate somehow to large-scale genome evolution. Current research is inclined to relate base skew with mutations and their fixation. Here we wish to explore base skew correlations in bird genomes, to develop methods for displaying and quantifying such correlations at different scales, and to discuss possible explanations for the peculiarities of the bird genomes in skew correlation. Results We have developed a method called Base Skew Double Triangle (BSDT for exhibiting the genome-scale change of AT/CG skew as a two-dimensional square picture, showing base skews at many scales simultaneously in a single image. By this method we found that most chicken chromosomes have high AT/CG skew correlation (symmetry in 2D picture, except for some microchromosomes. No other organisms studied (18 species show such high skew correlations. This visualized high correlation was validated by three kinds of quantitative calculations with overlapping and non-overlapping windows, all indicating that chicken and birds in general have a special genome structure. Similar features were also found in some of the mammal genomes, but clearly much weaker than in chickens. We presume that the skew correlation feature evolved near the time that birds separated from other vertebrate lineages. When we eliminated the repeat sequences from the genomes, the AT and CG skews correlation increased for some mammal genomes, but were still clearly lower than in chickens. Conclusion Our results suggest that BSDT is an expressive visualization method for AT and CG skew and enabled the discovery of the very high skew correlation in bird genomes; this peculiarity is worth further study. Computational analysis indicated that this correlation might be a compositional characteristic

  17. Subordinate wasps are more aggressive in colonies with low reproductive skew

    DEFF Research Database (Denmark)

    Fanelli, D.; Boomsma, Jacobus Jan; Turillazzi, S.

    2008-01-01

    The small societies of primitively eusocial wasps have provided interesting testing grounds for reproductive skew theory because all individuals have similar reproductive potential, which is unusual in social insects but common in vertebrate societies. Aggression is a key parameter in testing the...

  18. The curious anomaly of skewed judgment distributions and systematic error in the wisdom of crowds.

    Directory of Open Access Journals (Sweden)

    Ulrik W Nash

    Full Text Available Judgment distributions are often skewed and we know little about why. This paper explains the phenomenon of skewed judgment distributions by introducing the augmented quincunx (AQ model of sequential and probabilistic cue categorization by neurons of judges. In the process of developing inferences about true values, when neurons categorize cues better than chance, and when the particular true value is extreme compared to what is typical and anchored upon, then populations of judges form skewed judgment distributions with high probability. Moreover, the collective error made by these people can be inferred from how skewed their judgment distributions are, and in what direction they tilt. This implies not just that judgment distributions are shaped by cues, but that judgment distributions are cues themselves for the wisdom of crowds. The AQ model also predicts that judgment variance correlates positively with collective error, thereby challenging what is commonly believed about how diversity and collective intelligence relate. Data from 3053 judgment surveys about US macroeconomic variables obtained from the Federal Reserve Bank of Philadelphia and the Wall Street Journal provide strong support, and implications are discussed with reference to three central ideas on collective intelligence, these being Galton's conjecture on the distribution of judgments, Muth's rational expectations hypothesis, and Page's diversity prediction theorem.

  19. Development of a Skewed Pipe Shear Connector for Precast Concrete Structures.

    Science.gov (United States)

    Kim, Sang-Hyo; Choi, Jae-Gu; Park, Sejun; Lee, Hyunmin; Heo, And Won-Ho

    2017-05-13

    Joint connection methods, such as shear key and loop bar, improve the structural performance of precast concrete structures; consequently, there is usually decreased workability or constructional efficiency. This paper proposes a high-efficiency skewed pipe shear connector. To resist shear and pull-out forces, the proposed connectors are placed diagonally between precast concrete segments and a cast-in-place concrete joint part on a girder. Design variables (such as the pipe diameter, length, and insertion angle) have been examined to investigate the connection performance of the proposed connector. The results of our testing indicate that the skewed pipe shear connectors have 50% higher ductility and a 15% higher ratio of maximum load to yield strength as compared to the corresponding parameters of the loop bar. Finite element analysis was used for validation. The resulting validation indicates that, compared to the loop bar, the skewed pipe shear connector has a higher ultimate shear and pull-out resistance. These results indicate that the skewed pipe shear connector demonstrates more idealized behavior than the loop bar in precast concrete structures.

  20. On the skew-symmetric character of the couple-stress tensor

    OpenAIRE

    Hadjesfandiari, Ali R.

    2013-01-01

    In this paper, the skew-symmetric character of the couple-stress tensor is established as the result of arguments from tensor analysis. Consequently, the couple-stress pseudo-tensor has a true vectorial character. The fundamental step in this development is that the isotropic couple-stress tensor cannot exist.

  1. The generalised Sylvester matrix equations over the generalised bisymmetric and skew-symmetric matrices

    Science.gov (United States)

    Dehghan, Mehdi; Hajarian, Masoud

    2012-08-01

    A matrix P is called a symmetric orthogonal if P = P T = P -1. A matrix X is said to be a generalised bisymmetric with respect to P if X = X T = PXP. It is obvious that any symmetric matrix is also a generalised bisymmetric matrix with respect to I (identity matrix). By extending the idea of the Jacobi and the Gauss-Seidel iterations, this article proposes two new iterative methods, respectively, for computing the generalised bisymmetric (containing symmetric solution as a special case) and skew-symmetric solutions of the generalised Sylvester matrix equation ? (including Sylvester and Lyapunov matrix equations as special cases) which is encountered in many systems and control applications. When the generalised Sylvester matrix equation has a unique generalised bisymmetric (skew-symmetric) solution, the first (second) iterative method converges to the generalised bisymmetric (skew-symmetric) solution of this matrix equation for any initial generalised bisymmetric (skew-symmetric) matrix. Finally, some numerical results are given to illustrate the effect of the theoretical results.

  2. An algorithm to construct the basic algebra of a skew group algebra

    NARCIS (Netherlands)

    Horobeţ, E.

    2016-01-01

    We give an algorithm for the computation of the basic algebra Morita equivalent to a skew group algebra of a path algebra by obtaining formulas for the number of vertices and arrows of the new quiver Qb. We apply this algorithm to compute the basic algebra corresponding to all simple quaternion

  3. Consistent paternity skew through ontogeny in Peron's tree frog (Litoria peronii.

    Directory of Open Access Journals (Sweden)

    Craig D H Sherman

    Full Text Available BACKGROUND: A large number of studies in postcopulatory sexual selection use paternity success as a proxy for fertilization success. However, selective mortality during embryonic development can lead to skews in paternity in situations of polyandry and sperm competition. Thus, when assessment of paternity fails to incorporate mortality skews during early ontogeny, this may interfere with correct interpretation of results and subsequent evolutionary inference. In a previous series of in vitro sperm competition experiments with amphibians (Litoria peronii, we showed skewed paternity patterns towards males more genetically similar to the female. METHODOLOGY/PRINCIPAL FINDINGS: Here we use in vitro fertilizations and sperm competition trials to test if this pattern of paternity of fully developed tadpoles reflects patterns of paternity at fertilization and if paternity skews changes during embryonic development. We show that there is no selective mortality through ontogeny and that patterns of paternity of hatched tadpoles reflects success of competing males in sperm competition at fertilization. CONCLUSIONS/SIGNIFICANCE: While this study shows that previous inferences of fertilization success from paternity data are valid for this species, rigorous testing of these assumptions is required to ensure that differential embryonic mortality does not confound estimations of true fertilization success.

  4. Genotype and phenotype in Klinefelter syndrome - impact of androgen receptor polymorphism and skewed X inactivation

    DEFF Research Database (Denmark)

    Bojesen, A; Hertz, J M; Gravholt, C H

    2011-01-01

    The phenotypic variation of Klinefelter syndrome (KS) is wide and may by caused by various genetic and epigenetic effects. Skewed inactivation of the supra-numerical X chromosome and polymorphism in the androgen receptor (AR) have been suggested as plausible causes. We wanted to describe X...

  5. Widely Linear Blind Adaptive Equalization for Transmitter IQ-Imbalance/Skew Compensation in Multicarrier Systems

    DEFF Research Database (Denmark)

    Porto da Silva, Edson; Zibar, Darko

    2016-01-01

    Simple analytical widely linear complex-valued models for IQ-imbalance and IQ-skew effects in multicarrier transmitters are presented. To compensate for such effects, a 4×4 MIMO widely linear adaptive equalizer is proposed and experimentally validated....

  6. Bayesian semiparametric mixture Tobit models with left censoring, skewness, and covariate measurement errors.

    Science.gov (United States)

    Dagne, Getachew A; Huang, Yangxin

    2013-09-30

    Common problems to many longitudinal HIV/AIDS, cancer, vaccine, and environmental exposure studies are the presence of a lower limit of quantification of an outcome with skewness and time-varying covariates with measurement errors. There has been relatively little work published simultaneously dealing with these features of longitudinal data. In particular, left-censored data falling below a limit of detection may sometimes have a proportion larger than expected under a usually assumed log-normal distribution. In such cases, alternative models, which can account for a high proportion of censored data, should be considered. In this article, we present an extension of the Tobit model that incorporates a mixture of true undetectable observations and those values from a skew-normal distribution for an outcome with possible left censoring and skewness, and covariates with substantial measurement error. To quantify the covariate process, we offer a flexible nonparametric mixed-effects model within the Tobit framework. A Bayesian modeling approach is used to assess the simultaneous impact of left censoring, skewness, and measurement error in covariates on inference. The proposed methods are illustrated using real data from an AIDS clinical study. . Copyright © 2013 John Wiley & Sons, Ltd.

  7. The Use of the Skew T, Log P Diagram in Analysis and Forecasting. Revision

    Science.gov (United States)

    1990-03-01

    28 x 30 been added to further enhance the value of the inches. This version now includes the Apple - diagram. A detailed description of the Skew T, man...airocrau rqor we ovailable. The eauning lIkIaatte U the lop rate Is. at times. recorded as swot - adobaik wheun the mulm leave* a cloud Up and ener

  8. Cavitation Simulation on Conventional and Highly-Skewed Propellers in the Behind Condition

    DEFF Research Database (Denmark)

    Shin, Keun Woo; Andersen, Poul; Mikkelsen, Robert Flemming

    2011-01-01

    The cavitating flows around conventional and highly-skewed propellers in the behind-hull condition are simulated by an in-house RANS solver, EllipSys (Sørensen 2003), with the cavitation model, based on the homogeneous equilibrium modeling (HEM) approach and a vapor transport equation. The valida...

  9. Impaired imprinted X chromosome inactivation is responsible for the skewed sex ratio following in vitro fertilization

    Science.gov (United States)

    Tan, Kun; An, Lei; Miao, Kai; Ren, Likun; Hou, Zhuocheng; Tao, Li; Zhang, Zhenni; Wang, Xiaodong; Xia, Wei; Liu, Jinghao; Wang, Zhuqing; Xi, Guangyin; Gao, Shuai; Sui, Linlin; Zhu, De-Sheng; Wang, Shumin; Wu, Zhonghong; Bach, Ingolf; Chen, Dong-bao; Tian, Jianhui

    2016-01-01

    Dynamic epigenetic reprogramming occurs during normal embryonic development at the preimplantation stage. Erroneous epigenetic modifications due to environmental perturbations such as manipulation and culture of embryos during in vitro fertilization (IVF) are linked to various short- or long-term consequences. Among these, the skewed sex ratio, an indicator of reproductive hazards, was reported in bovine and porcine embryos and even human IVF newborns. However, since the first case of sex skewing reported in 1991, the underlying mechanisms remain unclear. We reported herein that sex ratio is skewed in mouse IVF offspring, and this was a result of female-biased peri-implantation developmental defects that were originated from impaired imprinted X chromosome inactivation (iXCI) through reduced ring finger protein 12 (Rnf12)/X-inactive specific transcript (Xist) expression. Compensation of impaired iXCI by overexpression of Rnf12 to up-regulate Xist significantly rescued female-biased developmental defects and corrected sex ratio in IVF offspring. Moreover, supplementation of an epigenetic modulator retinoic acid in embryo culture medium up-regulated Rnf12/Xist expression, improved iXCI, and successfully redeemed the skewed sex ratio to nearly 50% in mouse IVF offspring. Thus, our data show that iXCI is one of the major epigenetic barriers for the developmental competence of female embryos during preimplantation stage, and targeting erroneous epigenetic modifications may provide a potential approach for preventing IVF-associated complications. PMID:26951653

  10. Effects of trophic skewing of species richness on ecosystem functioning in a diverse marine community.

    Directory of Open Access Journals (Sweden)

    Pamela L Reynolds

    Full Text Available Widespread overharvesting of top consumers of the world's ecosystems has "skewed" food webs, in terms of biomass and species richness, towards a generally greater domination at lower trophic levels. This skewing is exacerbated in locations where exotic species are predominantly low-trophic level consumers such as benthic macrophytes, detritivores, and filter feeders. However, in some systems where numerous exotic predators have been added, sometimes purposefully as in many freshwater systems, food webs are skewed in the opposite direction toward consumer dominance. Little is known about how such modifications to food web topology, e.g., changes in the ratio of predator to prey species richness, affect ecosystem functioning. We experimentally measured the effects of trophic skew on production in an estuarine food web by manipulating ratios of species richness across three trophic levels in experimental mesocosms. After 24 days, increasing macroalgal richness promoted both plant biomass and grazer abundance, although the positive effect on plant biomass disappeared in the presence of grazers. The strongest trophic cascade on the experimentally stocked macroalgae emerged in communities with a greater ratio of prey to predator richness (bottom-rich food webs, while stronger cascades on the accumulation of naturally colonizing algae (primarily microalgae with some early successional macroalgae that recruited and grew in the mesocosms generally emerged in communities with greater predator to prey richness (the more top-rich food webs. These results suggest that trophic skewing of species richness and overall changes in food web topology can influence marine community structure and food web dynamics in complex ways, emphasizing the need for multitrophic approaches to understand the consequences of marine extinctions and invasions.

  11. Using purine skews to predict genes in AT-rich poxviruses

    Directory of Open Access Journals (Sweden)

    Upton Chris

    2005-02-01

    Full Text Available Abstract Background Clusters or runs of purines on the mRNA synonymous strand have been found in many different organisms including orthopoxviruses. The purine bias that is exhibited by these clusters can be observed using a purine skew and in the case of poxviruses, these skews can be used to help determine the coding strand of a particular segment of the genome. Combined with previous findings that minor ORFs have lower than average aspartate and glutamate composition and higher than average serine composition, purine content can be used to predict the likelihood of a poxvirus ORF being a "real gene". Results Using purine skews and a "quality" measure designed to incorporate previous findings about minor ORFs, we have found that in our training case (vaccinia virus strain Copenhagen, 59 of 65 minor (small and unlikely to be a real genes ORFs were correctly classified as being minor. Of the 201 major (large and likely to be real genes vaccinia ORFs, 192 were correctly classified as being major. Performing a similar analysis with the entomopoxvirus amsacta moorei (AMEV, it was found that 4 major ORFs were incorrectly classified as minor and 9 minor ORFs were incorrectly classified as major. The purine abundance observed for major ORFs in vaccinia virus was found to stem primarily from the first codon position with both the second and third codon positions containing roughly equal amounts of purines and pyrimidines. Conclusion Purine skews and a "quality" measure can be used to predict functional ORFs and purine skews in particular can be used to determine which of two overlapping ORFs is most likely to be the real gene if neither of the two ORFs has orthologs in other poxviruses.

  12. Demographic origins of skewed operational and adult sex ratios: perturbation analyses of two-sex models.

    Science.gov (United States)

    Veran, Sophie; Beissinger, Steven R

    2009-02-01

    Skewed sex ratios - operational (OSR) and Adult (ASR) - arise from sexual differences in reproductive behaviours and adult survival rates due to the cost of reproduction. However, skewed sex-ratio at birth, sex-biased dispersal and immigration, and sexual differences in juvenile mortality may also contribute. We present a framework to decompose the roles of demographic traits on sex ratios using perturbation analyses of two-sex matrix population models. Metrics of sensitivity are derived from analyses of sensitivity, elasticity, life-table response experiments and life stage simulation analyses, and applied to the stable stage distribution instead of lambda. We use these approaches to examine causes of male-biased sex ratios in two populations of green-rumped parrotlets (Forpus passerinus) in Venezuela. Female local juvenile survival contributed the most to the unbalanced OSR and ASR due to a female-biased dispersal rate, suggesting sexual differences in philopatry can influence sex ratios more strongly than the cost of reproduction.

  13. Surveying and optical tooling technologies combined to align a skewed beamline at the LAMPF accelerator

    International Nuclear Information System (INIS)

    Bauke, W.; Clark, D.A.; Trujillo, P.B.

    1985-01-01

    Optical Tooling evolved from traditional surveying, and both technologies are sometimes used interchangeably in large industrial installations, since the instruments and their specialized adapters and supports complement each other well. A unique marriage of both technologies was accomplished in a novel application at LAMPF, the Los Alamos Meson Physics Facility. LAMPF consists of a linear accelerator with multiple target systems, one of which had to be altered to accommodate a new beamline for a neutrino experiment. The new line was to be installed into a crowded beam tunnel and had to be skewed and tilted in compound angles to avoid existing equipment. In this paper we describe how Optical Tooling was used in conjunction with simple alignment and reference fixtures to set fiducials on the magnets and other mechanical components of the beamline, and how theodolites and sight levels were then adapted to align these components along the calculated skew planes. Design tolerances are compared with measured alignment results

  14. Multi-objective mean-variance-skewness model for generation portfolio allocation in electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    Pindoriya, N.M.; Singh, S.N. [Department of Electrical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Singh, S.K. [Indian Institute of Management Lucknow, Lucknow 226013 (India)

    2010-10-15

    This paper proposes an approach for generation portfolio allocation based on mean-variance-skewness (MVS) model which is an extension of the classical mean-variance (MV) portfolio theory, to deal with assets whose return distribution is non-normal. The MVS model allocates portfolios optimally by considering the maximization of both the expected return and skewness of portfolio return while simultaneously minimizing the risk. Since, it is competing and conflicting non-smooth multi-objective optimization problem, this paper employed a multi-objective particle swarm optimization (MOPSO) based meta-heuristic technique to provide Pareto-optimal solution in a single simulation run. Using a case study of the PJM electricity market, the performance of the MVS portfolio theory based method and the classical MV method is compared. It has been found that the MVS portfolio theory based method can provide significantly better portfolios in the situation where non-normally distributed assets exist for trading. (author)

  15. SKEWNESS IN STOCK RETURNS: EVIDENCE FROM THE BUCHAREST STOCK EXCHANGE DURING 2000 – 2011

    Directory of Open Access Journals (Sweden)

    IULIAN PANAIT

    2012-05-01

    Full Text Available Our paper investigates the symmetry in stock returns of the 30 most liquid companies traded on Bucharest Stock Exchange during 2000 – 2011 and also the most representative 5 market indices. Our daily data shows that skewness estimates are slightly negative for most indices and individual stocks, but only a few present values significantly different from the characteristics of a normal distribution. We compare our results with skewness estimates for 21 major and emerging stock market indices around the world and find that such results are similar to other low capitalization and trading volume markets. For all the Romanian and international assets studied, the Studentized-Range (St-R and Jarque-Bera (J-B tests reject the hypothesis of normal distribution of daily returns.

  16. Breeding system and reproductive skew in a highly polygynous ant population

    DEFF Research Database (Denmark)

    Haag-Liautard, C.; Pedersen, Jes Søe; Ovaskainen, O.

    2008-01-01

    of mature queens by mark-release-recapture in 29 nests and dissected a sub-sample of queens to assess their reproductive status. We also used microsatellites to estimate relatedness within and between all classes of nestmates (queens, their mates, worker brood, queen brood and male brood). Queen number...... Factors affecting relatedness among nest members in ant colonies with high queen number are still poorly understood. In order to identify the major determinants of nest kin structure, we conducted a detailed analysis of the breeding system of the ant Formica exsecta. We estimated the number...... was very high, with an arithmetic mean of 253 per nest. Most queens (90%) were reproductively active, consistent with the genetic analyses revealing that there was only a minimal reproductive skew among nestmate queens. Despite the high queen number and low reproductive skew, almost all classes...

  17. Multi-objective mean-variance-skewness model for generation portfolio allocation in electricity markets

    International Nuclear Information System (INIS)

    Pindoriya, N.M.; Singh, S.N.; Singh, S.K.

    2010-01-01

    This paper proposes an approach for generation portfolio allocation based on mean-variance-skewness (MVS) model which is an extension of the classical mean-variance (MV) portfolio theory, to deal with assets whose return distribution is non-normal. The MVS model allocates portfolios optimally by considering the maximization of both the expected return and skewness of portfolio return while simultaneously minimizing the risk. Since, it is competing and conflicting non-smooth multi-objective optimization problem, this paper employed a multi-objective particle swarm optimization (MOPSO) based meta-heuristic technique to provide Pareto-optimal solution in a single simulation run. Using a case study of the PJM electricity market, the performance of the MVS portfolio theory based method and the classical MV method is compared. It has been found that the MVS portfolio theory based method can provide significantly better portfolios in the situation where non-normally distributed assets exist for trading. (author)

  18. Mutual tolerance or reproductive competition? Patterns of reproductive skew among male redfronted lemurs (Eulemur fulvus rufus)

    OpenAIRE

    Kappeler, Peter M.; Port, Markus

    2008-01-01

    The social organization of gregarious lemurs significantly deviates from predictions of the socioecological model, as they form small groups in which the number of males approximately equals the number of females. This study uses models of reproductive skew theory as a new approach to explain this unusual group composition, in particular the high number of males, in a representative of these lemurs, the redfronted lemur (Eulemur fulvus rufus). We tested two central predictions of “concession”...

  19. Dip and anisotropy effects on flow using a vertically skewed model grid.

    Science.gov (United States)

    Hoaglund, John R; Pollard, David

    2003-01-01

    Darcy flow equations relating vertical and bedding-parallel flow to vertical and bedding-parallel gradient components are derived for a skewed Cartesian grid in a vertical plane, correcting for structural dip given the principal hydraulic conductivities in bedding-parallel and bedding-orthogonal directions. Incorrect-minus-correct flow error results are presented for ranges of structural dip (0 strike and dip, and a solver that can handle off-diagonal hydraulic conductivity terms.

  20. Fast and Accurate Ground Truth Generation for Skew-Tolerance Evaluation of Page Segmentation Algorithms

    Directory of Open Access Journals (Sweden)

    Okun Oleg

    2006-01-01

    Full Text Available Many image segmentation algorithms are known, but often there is an inherent obstacle in the unbiased evaluation of segmentation quality: the absence or lack of a common objective representation for segmentation results. Such a representation, known as the ground truth, is a description of what one should obtain as the result of ideal segmentation, independently of the segmentation algorithm used. The creation of ground truth is a laborious process and therefore any degree of automation is always welcome. Document image analysis is one of the areas where ground truths are employed. In this paper, we describe an automated tool called GROTTO intended to generate ground truths for skewed document images, which can be used for the performance evaluation of page segmentation algorithms. Some of these algorithms are claimed to be insensitive to skew (tilt of text lines. However, this fact is usually supported only by a visual comparison of what one obtains and what one should obtain since ground truths are mostly available for upright images, that is, those without skew. As a result, the evaluation is both subjective; that is, prone to errors, and tedious. Our tool allows users to quickly and easily produce many sufficiently accurate ground truths that can be employed in practice and therefore it facilitates automatic performance evaluation. The main idea is to utilize the ground truths available for upright images and the concept of the representative square [9] in order to produce the ground truths for skewed images. The usefulness of our tool is demonstrated through a number of experiments with real-document images of complex layout.

  1. An extraction of the skewing factor from DESY-HERA data

    International Nuclear Information System (INIS)

    Favart, Laurent; Machado, Magno V.T.; Schoeffel, Laurent

    2007-01-01

    In this contribution we present recent investigation on the extraction of the skewing factor, defined as the ratio of the imaginary parts of the amplitudes ImA (gamma * p → gamma * p) / ImA (gamma * p → gamma p). This factor is extracted from the data using the recent DVCS and the inclusive inelastic cross section measurements at DESY-HERA. We compare the results to the theoretical predictions for NLO QCD and the color dipole approach. (author)

  2. Stock Markets Volatility Spillovers during Financial Crises : A DCC-MGARCH with Skew-t Approach

    OpenAIRE

    Bala, Dahiru A.; Takimoto, Taro

    2016-01-01

    We investigate stock markets volatility spillovers in selected emerging and major developed markets using multivariate GARCH (MGARCH) models [namely; DVECH, CCC-MGARCH, CCC-VARMA-(A)MGARCH, VAR-EGARCH, BEKK-(A)MGARCH, DCC-MGARCH (with Gaussian and t distributions) and DCC-with-skew-t density]. The paper analyses the impacts of recent global financial crisis (2007{2009) on stock market volatility and examines their dynamic interactions using several MGARCH model variants. Structural break dete...

  3. Environmental Effects on Flutter Characteristics of Laminated Composite Rectangular and Skew Panels

    Directory of Open Access Journals (Sweden)

    T.V.R. Chowdary

    1996-01-01

    Full Text Available A finite element method is presented for predicting the flutter response of laminated composite panels subjected to moisture concentration and temperature. The analysis accounts for material properties at elevated temperature and moisture concentration. The analysis is based on the first-order approximation to the linear piston theory and laminated plate theory that includes shear deformation. Both rectangular and skew panels are considered. Stability boundaries at moisture concentrations and temperatures for various lamination schemes and boundary conditions are discussed.

  4. Approaches to characterise chromatographic column performance based on global parameters accounting for peak broadening and skewness.

    Science.gov (United States)

    Baeza-Baeza, J J; Pous-Torres, S; Torres-Lapasió, J R; García-Alvarez-Coque, M C

    2010-04-02

    Peak broadening and skewness are fundamental parameters in chromatography, since they affect the resolution capability of a chromatographic column. A common practice to characterise chromatographic columns is to estimate the efficiency and asymmetry factor for the peaks of one or more solutes eluted at selected experimental conditions. This has the drawback that the extra-column contributions to the peak variance and skewness make the peak shape parameters depend on the retention time. We propose and discuss here the use of several approaches that allow the estimation of global parameters (non-dependent on the retention time) to describe the column performance. The global parameters arise from different linear relationships that can be established between the peak variance, standard deviation, or half-widths with the retention time. Some of them describe exclusively the column contribution to the peak broadening, whereas others consider the extra-column effects also. The estimation of peak skewness was also possible for the approaches based on the half-widths. The proposed approaches were applied to the characterisation of different columns (Spherisorb, Zorbax SB, Zorbax Eclipse, Kromasil, Chromolith, X-Terra and Inertsil), using the chromatographic data obtained for several diuretics and basic drugs (beta-blockers). Copyright (c) 2010 Elsevier B.V. All rights reserved.

  5. Squaring the Circle: Geometric Skewness and Symmetry Breaking for Passive Scalar Transport in Ducts and Pipes.

    Science.gov (United States)

    Aminian, Manuchehr; Bernardi, Francesca; Camassa, Roberto; McLaughlin, Richard M

    2015-10-09

    We study the role geometry plays in the emergence of asymmetries in diffusing passive scalars advected by pressure-driven flows in ducts and pipes of different aspect ratios. We uncover nonintuitive, multi-time-scale behavior gauged by a new statistic, which we term "geometric skewness" S^{G}, which measures instantaneously forming asymmetries at short times due to flow geometry. This signature distinguishes elliptical pipes of any aspect ratio, for which S^{G}=0, from rectangular ducts whose S^{G} is generically nonzero, and, interestingly, shows that a special duct of aspect ratio ≈0.53335 behaves like a circular pipe as its geometric skewness vanishes. Using a combination of exact solutions, novel short-time asymptotics, and Monte Carlo simulations, we establish the relevant time scales for plateaus and extrema in the evolution of the skewness and kurtosis for our class of geometries. For ducts limiting to channel geometries, we present new exact, single-series formulas for the first four moments on slices used to benchmark Monte Carlo simulations.

  6. The skewed weak lensing likelihood: why biases arise, despite data and theory being sound.

    Science.gov (United States)

    Sellentin, Elena; Heymans, Catherine; Harnois-Déraps, Joachim

    2018-04-01

    We derive the essentials of the skewed weak lensing likelihood via a simple Hierarchical Forward Model. Our likelihood passes four objective and cosmology-independent tests which a standard Gaussian likelihood fails. We demonstrate that sound weak lensing data are naturally biased low, since they are drawn from a skewed distribution. This occurs already in the framework of ΛCDM. Mathematically, the biases arise because noisy two-point functions follow skewed distributions. This form of bias is already known from CMB analyses, where the low multipoles have asymmetric error bars. Weak lensing is more strongly affected by this asymmetry as galaxies form a discrete set of shear tracer particles, in contrast to a smooth shear field. We demonstrate that the biases can be up to 30% of the standard deviation per data point, dependent on the properties of the weak lensing survey and the employed filter function. Our likelihood provides a versatile framework with which to address this bias in future weak lensing analyses.

  7. Skin friction measurements of systematically-varied roughness: Probing the role of roughness amplitude and skewness

    Science.gov (United States)

    Barros, Julio; Flack, Karen; Schultz, Michael

    2017-11-01

    Real-world engineering systems which feature either external or internal wall-bounded turbulent flow are routinely affected by surface roughness. This gives rise to performance degradation in the form of increased drag or head loss. However, at present there is no reliable means to predict these performance losses based upon the roughness topography alone. This work takes a systematic approach by generating random surface roughness in which the surface statistics are closely controlled. Skin friction and roughness function results will be presented for two groups of these rough surfaces. The first group is Gaussian (i.e. zero skewness) in which the root-mean-square roughness height (krms) is varied. The second group has a fixed krms, and the skewness is varied from approximately -1 to +1. The effect of the roughness amplitude and skewness on the skin friction will be discussed. Particular attention will be paid to the effect of these parameters on the roughness function in the transitionally-rough flow regime. For example, the role these parameters play in the monotonic or inflectional nature of the roughness function will be addressed. Future research into the details of the turbulence structure over these rough surfaces will also be outlined. Research funded by U.S. Office of Naval Research (ONR).

  8. A Bayesian estimate of the concordance correlation coefficient with skewed data.

    Science.gov (United States)

    Feng, Dai; Baumgartner, Richard; Svetnik, Vladimir

    2015-01-01

    Concordance correlation coefficient (CCC) is one of the most popular scaled indices used to evaluate agreement. Most commonly, it is used under the assumption that data is normally distributed. This assumption, however, does not apply to skewed data sets. While methods for the estimation of the CCC of skewed data sets have been introduced and studied, the Bayesian approach and its comparison with the previous methods has been lacking. In this study, we propose a Bayesian method for the estimation of the CCC of skewed data sets and compare it with the best method previously investigated. The proposed method has certain advantages. It tends to outperform the best method studied before when the variation of the data is mainly from the random subject effect instead of error. Furthermore, it allows for greater flexibility in application by enabling incorporation of missing data, confounding covariates, and replications, which was not considered previously. The superiority of this new approach is demonstrated using simulation as well as real-life biomarker data sets used in an electroencephalography clinical study. The implementation of the Bayesian method is accessible through the Comprehensive R Archive Network. Copyright © 2015 John Wiley & Sons, Ltd.

  9. A review of statistical estimators for risk-adjusted length of stay: analysis of the Australian and new Zealand Intensive Care Adult Patient Data-Base, 2008-2009.

    Science.gov (United States)

    Moran, John L; Solomon, Patricia J

    2012-05-16

    For the analysis of length-of-stay (LOS) data, which is characteristically right-skewed, a number of statistical estimators have been proposed as alternatives to the traditional ordinary least squares (OLS) regression with log dependent variable. Using a cohort of patients identified in the Australian and New Zealand Intensive Care Society Adult Patient Database, 2008-2009, 12 different methods were used for estimation of intensive care (ICU) length of stay. These encompassed risk-adjusted regression analysis of firstly: log LOS using OLS, linear mixed model [LMM], treatment effects, skew-normal and skew-t models; and secondly: unmodified (raw) LOS via OLS, generalised linear models [GLMs] with log-link and 4 different distributions [Poisson, gamma, negative binomial and inverse-Gaussian], extended estimating equations [EEE] and a finite mixture model including a gamma distribution. A fixed covariate list and ICU-site clustering with robust variance were utilised for model fitting with split-sample determination (80%) and validation (20%) data sets, and model simulation was undertaken to establish over-fitting (Copas test). Indices of model specification using Bayesian information criterion [BIC: lower values preferred] and residual analysis as well as predictive performance (R2, concordance correlation coefficient (CCC), mean absolute error [MAE]) were established for each estimator. The data-set consisted of 111663 patients from 131 ICUs; with mean(SD) age 60.6(18.8) years, 43.0% were female, 40.7% were mechanically ventilated and ICU mortality was 7.8%. ICU length-of-stay was 3.4(5.1) (median 1.8, range (0.17-60)) days and demonstrated marked kurtosis and right skew (29.4 and 4.4 respectively). BIC showed considerable spread, from a maximum of 509801 (OLS-raw scale) to a minimum of 210286 (LMM). R2 ranged from 0.22 (LMM) to 0.17 and the CCC from 0.334 (LMM) to 0.149, with MAE 2.2-2.4. Superior residual behaviour was established for the log-scale estimators

  10. World Bank Development Sector Adjustment Operation Life Line to Nigerian Universities: Impact on Information Demand and Supply in the University of Agriculture, Makurdi Library.

    Science.gov (United States)

    Ozowa, Vincent Nnamdi

    1995-01-01

    Provides an overview of the rationale behind the World Bank credit line to Nigerian universities and examines the impact of the credit facility on the information demand and supply in the University of Agriculture, Makurdi Library (Nigeria). Discusses problems, such as poor quantity and quality of books and journals, lack of equipment, and lack of…

  11. A Simple Measure of Price Adjustment Coefficients.

    OpenAIRE

    Damodaran, Aswath

    1993-01-01

    One measure of market efficiency is the speed with which prices adjust to new information. The author develops a simple approach to estimating these price adjustment coefficients by using the information in return processes. This approach is used to estimate t he price adjustment coefficients for firms listed on the NYSE and the A MEX as well as for over-the-counter stocks. The author finds evidence of a lagged adjustment to new information in shorter return intervals for firms in all market ...

  12. The role of the SST-thermocline relationship in Indian Ocean Dipole skewness and its response to global warming

    Science.gov (United States)

    Ng, Benjamin; Cai, Wenju; Walsh, Kevin

    2014-01-01

    A positive Indian Ocean Dipole (IOD) tends to have stronger cold sea surface temperature anomalies (SSTAs) over the eastern Indian Ocean with greater impacts than warm SSTAs that occur during its negative phase. Two feedbacks have been suggested as the cause of positive IOD skewness, a positive Bjerknes feedback and a negative SST-cloud-radiation (SCR) feedback, but their relative importance is debated. Using inter-model statistics, we show that the most important process for IOD skewness is an asymmetry in the thermocline feedback, whereby SSTAs respond to thermocline depth anomalies more strongly during the positive phase than negative phase. This asymmetric thermocline feedback drives IOD skewness despite positive IODs receiving greater damping from the SCR feedback. In response to global warming, although the thermocline feedback strengthens, its asymmetry between positive and negative IODs weakens. This behaviour change explains the reduction in IOD skewness that many models display under global warming. PMID:25112717

  13. Stall inception and warning in a single-stage transonic axial compressor with axial skewed slot casing treatment

    International Nuclear Information System (INIS)

    Lim, Byeung Jun; Kwon, Se Jin; Park, Tae Choon

    2014-01-01

    Characteristic changes in the stall inception in a single-stage transonic axial compressor with an axial skewed slot casing treatment were investigated experimentally. A rotating stall occurred intermittently in a compressor with an axial skewed slot, whereas spike-type rotating stalls occurred in the case of smooth casing. The axial skewed slot suppressed stall cell growth and increased the operating range. A mild surge, the frequency of which is the Helmholtz frequency of the compressor system, occurred with the rotating stall. The irregularity in the pressure signals at the slot bottom increased decreasing flow rate. An autocorrelation-based stall warning method was applied to the measured pressure signals. Results estimate and warn against the stall margin in a compressor with an axial skewed slot.

  14. Impact of radius and skew angle on areal density in heat assisted magnetic recording hard disk drives

    Science.gov (United States)

    Cordle, Michael; Rea, Chris; Jury, Jason; Rausch, Tim; Hardie, Cal; Gage, Edward; Victora, R. H.

    2018-05-01

    This study aims to investigate the impact that factors such as skew, radius, and transition curvature have on areal density capability in heat-assisted magnetic recording hard disk drives. We explore a "ballistic seek" approach for capturing in-situ scan line images of the magnetization footprint on the recording media, and extract parametric results of recording characteristics such as transition curvature. We take full advantage of the significantly improved cycle time to apply a statistical treatment to relatively large samples of experimental curvature data to evaluate measurement capability. Quantitative analysis of factors that impact transition curvature reveals an asymmetry in the curvature profile that is strongly correlated to skew angle. Another less obvious skew-related effect is an overall decrease in curvature as skew angle increases. Using conventional perpendicular magnetic recording as the reference case, we characterize areal density capability as a function of recording position.

  15. A Skewed Student-t Value-at-Risk Approach for Long Memory Volatility Processes in Japanese Financial Markets

    Directory of Open Access Journals (Sweden)

    Seong¡-Min Yoon

    2007-06-01

    Full Text Available This paper investigates the relevance of skewed Student-t distributions in capturing long memory volatility properties in the daily return series of Japanese financial data (Nikkei 225 Index and JPY-USD exchange rate. For this purpose, we assess the performance of two long memory Value-at-Risk (VaR models (FIGARCH and FIAPARCH VaR model with three different distribution innovations: the normal, Student-t, and skewed Student-t distributions. From our results, we find that the skewed Student-t distribution model produces more accurate VaR estimations than normal and Student-t distribution models. Thus, accounting for skewness and excess kurtosis in the asset return distribution can provide suitable criteria for VaR model selection in the context of long memory volatility and enhance the performance of risk management in Japanese financial markets.

  16. Annual Adjustment Factors

    Data.gov (United States)

    Department of Housing and Urban Development — The Department of Housing and Urban Development establishes the rent adjustment factors - called Annual Adjustment Factors (AAFs) - on the basis of Consumer Price...

  17. Some case studies of skewed (and other ab-normal) data distributions arising in low-level environmental research

    International Nuclear Information System (INIS)

    Currie, L.A.

    2001-01-01

    Three general classes of skewed data distributions have been encountered in research on background radiation, chemical and radiochemical blanks, and low levels of 85 Kr and 14 C in the atmosphere and the cryosphere. The first class of skewed data can be considered to be theoretically, or fundamentally skewed. It is typified by the exponential distribution of inter-arrival times for nuclear counting events for a Poisson process. As part of a study of the nature of low-level (anti-coincidence) Geiger- Mueller counter background radiation, tests were performed on the Poisson distribution of counts, the uniform distribution of arrival times, and the exponential distribution of inter-arrival times. The real laboratory system, of course, failed the (inter-arrival time) test - for very interesting reasons, linked to the physics of the measurement process. The second, computationally skewed, class relates to skewness induced by non-linear transformations. It is illustrated by non-linear concentration estimates from inverse calibration, and bivariate blank corrections for low-level 14 C- 12 C aerosol data that led to highly asymmetric uncertainty intervals for the biomass carbon contribution to urban ''soot''. The third, environmentally skewed, data class relates to a universal problem for the detection of excursions above blank or baseline levels: namely, the widespread occurrence of ab-normal distributions of environmental and laboratory blanks. This is illustrated by the search for fundamental factors that lurk behind skewed frequency distributions of sulfur laboratory blanks and 85 Kr environmental baselines, and the application of robust statistical procedures for reliable detection decisions in the face of skewed isotopic carbon procedural blanks with few degrees of freedom. (orig.)

  18. Some case studies of skewed (and other ab-normal) data distributions arising in low-level environmental research.

    Science.gov (United States)

    Currie, L A

    2001-07-01

    Three general classes of skewed data distributions have been encountered in research on background radiation, chemical and radiochemical blanks, and low levels of 85Kr and 14C in the atmosphere and the cryosphere. The first class of skewed data can be considered to be theoretically, or fundamentally skewed. It is typified by the exponential distribution of inter-arrival times for nuclear counting events for a Poisson process. As part of a study of the nature of low-level (anti-coincidence) Geiger-Muller counter background radiation, tests were performed on the Poisson distribution of counts, the uniform distribution of arrival times, and the exponential distribution of inter-arrival times. The real laboratory system, of course, failed the (inter-arrival time) test--for very interesting reasons, linked to the physics of the measurement process. The second, computationally skewed, class relates to skewness induced by non-linear transformations. It is illustrated by non-linear concentration estimates from inverse calibration, and bivariate blank corrections for low-level 14C-12C aerosol data that led to highly asymmetric uncertainty intervals for the biomass carbon contribution to urban "soot". The third, environmentally, skewed, data class relates to a universal problem for the detection of excursions above blank or baseline levels: namely, the widespread occurrence of ab-normal distributions of environmental and laboratory blanks. This is illustrated by the search for fundamental factors that lurk behind skewed frequency distributions of sulfur laboratory blanks and 85Kr environmental baselines, and the application of robust statistical procedures for reliable detection decisions in the face of skewed isotopic carbon procedural blanks with few degrees of freedom.

  19. Patients' experiences of intervention trials on the treatment of myocardial infarction: is it time to adjust the informed consent procedure to the patient's capacity?

    OpenAIRE

    Agard, A; Hermeren, G; Herlitz, J

    2001-01-01

    OBJECTIVE—To investigate how patients included in trials on treatment in the early phase of acute myocardial infarction experience the consent procedure.
DESIGN—A combined qualitative and quantitative interview concerning the patients' knowledge of the trial, their feelings about being asked to participate, and their attitudes towards the consent procedure.
SETTING—Tertiary referral centre.
PATIENTS—31 patients who had given written informed consent for their participation in randomised inter...

  20. Electronic gaming and psychosocial adjustment.

    Science.gov (United States)

    Przybylski, Andrew K

    2014-09-01

    The rise of electronic games has driven both concerns and hopes regarding their potential to influence young people. Existing research identifies a series of isolated positive and negative effects, yet no research to date has examined the balance of these potential effects in a representative sample of children and adolescents. The objective of this study was to explore how time spent playing electronic games accounts for significant variation in positive and negative psychosocial adjustment using a representative cohort of children aged 10 to 15 years. A large sample of children and adolescents aged 10 to 15 years completed assessments of psychosocial adjustment and reported typical daily hours spent playing electronic games. Relations between different levels of engagement and indicators of positive and negative psychosocial adjustment were examined, controlling for participant age and gender and weighted for population representativeness. Low levels (3 hours daily) of game engagement was linked to key indicators of psychosocial adjustment. Low engagement was associated with higher life satisfaction and prosocial behavior and lower externalizing and internalizing problems, whereas the opposite was found for high levels of play. No effects were observed for moderate play levels when compared with non-players. The links between different levels of electronic game engagement and psychosocial adjustment were small (Games consistently but not robustly associated with children's adjustment in both positive and negative ways, findings that inform policy-making as well as future avenues for research in the area. Copyright © 2014 by the American Academy of Pediatrics.

  1. An information and communication technology-based centralized clinical trial to determine the efficacy and safety of insulin dose adjustment education based on a smartphone personal health record application: a randomized controlled trial.

    Science.gov (United States)

    Kim, Gyuri; Bae, Ji Cheol; Yi, Byoung Kee; Hur, Kyu Yeon; Chang, Dong Kyung; Lee, Moon-Kyu; Kim, Jae Hyeon; Jin, Sang-Man

    2017-07-18

    A Personal Health Record (PHR) is an online application that allows patients to access, manage, and share their health data. PHRs not only enhance shared decision making with healthcare providers, but also enable remote monitoring and at-home-collection of detailed data. The benefits of PHRs can be maximized in insulin dose adjustment for patients starting or intensifying insulin regimens, as frequent self-monitoring of glucose, self-adjustment of insulin dose, and precise at-home data collection during the visit-to-visit period are important for glycemic control. The aim of this study is to examine the efficacy and safety of insulin dose adjustment based on a smartphone PHR application in patients with diabetes mellitus (DM) and to confirm the validity and stability of an information and communication technology (ICT)-based centralized clinical trial monitoring system. This is a 24-week, open-label, randomized, multi-center trial. There are three follow-up measures: baseline, post-intervention at week 12, and at week 24. Subjects diagnosed with type 1 DM, type 2 DM, and/or post-transplant DM who initiate basal insulin or intensify their insulin regimen to a basal-bolus regimen are included. After education on insulin dose titration and prevention for hypoglycemia and a 1-week acclimation period, subjects are randomized in a 1:1 ratio to either an ICT-based intervention group or a conventional intervention group. Subjects in the conventional intervention group will save and send their health information to the server via a PHR application, whereas those in ICT-based intervention group will receive additional algorithm-based feedback messages. The health information includes level of blood glucose, insulin dose, details on hypoglycemia, food diary, and step count. The primary outcome will be the proportion of patients who reach an optimal insulin dose within 12 weeks of study enrollment, without severe hypoglycemia or unscheduled clinic visits. This clinical trial

  2. The Taming of the Skew: Facts On Canada’s Energy Trade

    Directory of Open Access Journals (Sweden)

    Trevor Tombe

    2014-03-01

    Full Text Available Public perception of Canada’s energy trade is skewed towards Alberta’s oilsands and pipeline projects; a look at the facts reveals a more complex picture. Over the last decade, growth in Canada’s energy trade has been nothing short of historic. Energy exports have become so significant that the revenue is now equivalent to nearly $9,000 for every Canadian household. And it is only projected to grow much, much larger. While Western Canada leads the industry, every region — including Ontario, Quebec and Atlantic Canada — plays a key role. Today, nearly every province is a net energy exporter. The energy sector also adds much to Canada’s economy, with valueadded and productivity higher than nearly every other sector. When it comes to labour compensation, oil and gas extraction is the highest-paying sector in the country, at more than three times the average hourly earnings in the Canadian economy generally, and nearly 50 per cent higher than manufacturing. It is vital that policy debates rely on accurate information; unfortunately, this is not always the case. The often heated rhetoric neglects important aspects of Canada’s energy trade. For example, the type of energy that Canada trades has undergone a dramatic transformation. Ten years ago, natural gas was the largest energy export but today accounts for less than one-tenth of the total. Meanwhile, crude oil exports have more than quadrupled. Even more surprising to many Canadians, and perhaps even policy-makers, is how much energy Canada imports. Even Alberta, with its vast energy reserves, imports a considerable amount of energy. Alberta’s energy imports have grown faster than any other province and will soon exceed Ontario’s, a province more than three times larger with very little of its own oil production. Trade in energy is also intimately tied with Canada’s foreign investment policies. The majority of Canada’s energy trade is in the form of related-party transactions

  3. Modeling multivariate time series on manifolds with skew radial basis functions.

    Science.gov (United States)

    Jamshidi, Arta A; Kirby, Michael J

    2011-01-01

    We present an approach for constructing nonlinear empirical mappings from high-dimensional domains to multivariate ranges. We employ radial basis functions and skew radial basis functions for constructing a model using data that are potentially scattered or sparse. The algorithm progresses iteratively, adding a new function at each step to refine the model. The placement of the functions is driven by a statistical hypothesis test that accounts for correlation in the multivariate range variables. The test is applied on training and validation data and reveals nonstatistical or geometric structure when it fails. At each step, the added function is fit to data contained in a spatiotemporally defined local region to determine the parameters--in particular, the scale of the local model. The scale of the function is determined by the zero crossings of the autocorrelation function of the residuals. The model parameters and the number of basis functions are determined automatically from the given data, and there is no need to initialize any ad hoc parameters save for the selection of the skew radial basis functions. Compactly supported skew radial basis functions are employed to improve model accuracy, order, and convergence properties. The extension of the algorithm to higher-dimensional ranges produces reduced-order models by exploiting the existence of correlation in the range variable data. Structure is tested not just in a single time series but between all pairs of time series. We illustrate the new methodologies using several illustrative problems, including modeling data on manifolds and the prediction of chaotic time series.

  4. Overcoming the effects of differential skewness of test items in scale construction

    Directory of Open Access Journals (Sweden)

    Johann M. Schepers

    2004-10-01

    Full Text Available The principal objective of the study was to develop a procedure for overcoming the effects of differential skewness of test items in scale construction. It was shown that the degree of skewness of test items places an upper limit on the correlations between the items, regardless of the contents of the items. If the items are ordered in terms of skewness the resulting inter correlation matrix forms a simplex or a pseudo simplex. Factoring such a matrix results in a multiplicity of factors, most of which are artifacts. A procedure for overcoming this problem was demonstrated with items from the Locus of Control Inventory (Schepers, 1995. The analysis was based on a sample of 1662 first year university students. Opsomming Die hoofdoel van die studie was om ’n prosedure te ontwikkel om die gevolge van differensiële skeefheid van toetsitems, in skaalkonstruksie, teen te werk. Daar is getoon dat die graad van skeefheid van toetsitems ’n boonste grens plaas op die korrelasies tussen die items ongeag die inhoud daarvan. Indien die items gerangskik word volgens graad van skeefheid, sal die interkorrelasiematriks van die items ’n simpleks of pseudosimpleks vorm. Indien so ’n matriks aan faktorontleding onderwerp word, lei dit tot ’n veelheid van faktore waarvan die meerderheid artefakte is. ’n Prosedure om hierdie probleem te bowe te kom, is gedemonstreer met behulp van die items van die Lokus van Beheer-vraelys (Schepers, 1995. Die ontledings is op ’n steekproef van 1662 eerstejaaruniversiteitstudente gebaseer.

  5. B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction

    OpenAIRE

    Shin, Jung Hoon; Park, Se-Ho

    2013-01-01

    CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although ?-galactosylceramide (?-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-? by NKT cells, concomitant with a d...

  6. The Universal Patient Centredness Questionnaire: scaling approaches to reduce positive skew

    Directory of Open Access Journals (Sweden)

    Bjertnaes O

    2016-11-01

    Full Text Available Oyvind Bjertnaes, Hilde Hestad Iversen, Andrew M Garratt Unit for Patient-Reported Quality, Norwegian Institute of Public Health, Oslo, Norway Purpose: Surveys of patients’ experiences typically show results that are indicative of positive experiences. Unbalanced response scales have reduced positive skew for responses to items within the Universal Patient Centeredness Questionnaire (UPC-Q. The objective of this study was to compare the unbalanced response scale with another unbalanced approach to scaling to assess whether the positive skew might be further reduced. Patients and methods: The UPC-Q was included in a patient experience survey conducted at the ward level at six hospitals in Norway in 2015. The postal survey included two reminders to nonrespondents. For patients in the first month of inclusion, UPC-Q items had standard scaling: poor, fairly good, good, very good, and excellent. For patients in the second month, the scaling was more positive: poor, good, very good, exceptionally good, and excellent. The effect of scaling on UPC-Q scores was tested with independent samples t-tests and multilevel linear regression analysis, the latter controlling for the hierarchical structure of data and known predictors of patient-reported experiences. Results: The response rate was 54.6% (n=4,970. Significantly lower scores were found for all items of the more positively worded scale: UPC-Q total score difference was 7.9 (P<0.001, on a scale from 0 to 100 where 100 is the best possible score. Differences between the four items of the UPC-Q ranged from 7.1 (P<0.001 to 10.4 (P<0.001. Multivariate multilevel regression analysis confirmed the difference between the response groups, after controlling for other background variables; UPC-Q total score difference estimate was 8.3 (P<0.001. Conclusion: The more positively worded scaling significantly lowered the mean scores, potentially increasing the sensitivity of the UPC-Q to identify differences over

  7. Uniform persistence and upper Lyapunov exponents for monotone skew-product semiflows

    International Nuclear Information System (INIS)

    Novo, Sylvia; Obaya, Rafael; Sanz, Ana M

    2013-01-01

    Several results of uniform persistence above and below a minimal set of an abstract monotone skew-product semiflow are obtained. When the minimal set has a continuous separation the results are given in terms of the principal spectrum. In the case that the semiflow is generated by the solutions of a family of non-autonomous differential equations of ordinary, delay or parabolic type, the former results are strongly improved. A method of calculus of the upper Lyapunov exponent of the minimal set is also determined. (paper)

  8. The Curious Anomaly of Skewed Judgment Distributions and Systematic Error in the Wisdom of Crowds

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    about true values, when neurons categorize cues better than chance, and when the particular true value is extreme compared to what is typical and anchored upon, then populations of judges form skewed judgment distributions with high probability. Moreover, the collective error made by these people can...... positively with collective error, thereby challenging what is commonly believed about how diversity and collective intelligence relate. Data from 3053 judgment surveys about US macroeconomic variables obtained from the Federal Reserve Bank of Philadelphia and the Wall Street Journal provide strong support...

  9. Skewed X-chromosome inactivation in female carriers of dyskeratosis congenita

    Energy Technology Data Exchange (ETDEWEB)

    Devriendt, K.; Matthijs, G.; Legius, E. [Univ. Hospital Gasthuisberg, Leuven (Belgium)] [and others

    1997-03-01

    In this study, we report on a family with X-linked dyskeratosis congenita (DC). Linkage analysis with markers in the factor VIII gene at Xq28 yielded a LOD score of 2 at a recombination of 0. Clinical manifestations of DC, such as skin lesions following the Blaschko lines, were present in two obligate carrier females. Highly skewed X inactivation was observed in white blood cells, cultured skin fibroblasts, and buccal mucosa from female carriers of DC in this family. This suggests a critical role for the DC gene in bone marrow-cell and fibroblast-cell proliferation. 23 refs., 4 figs., 1 tab.

  10. The Atacama Cosmology Telescope: A Measurement of the Thermal Sunyaev-Zel'dovich Effect Using the Skewness of the CMB Temperature Distribution

    Science.gov (United States)

    Wilson, Michael J.; Sherwin, Blake D.; Hill, J. Collin; Addison, Graeme; Battaglia, Nick; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Dunkley, Joanna; Duenner, Rolando; hide

    2012-01-01

    We present a detection of the unnormalized skewness (T(sup )(sup 2)(n(circumflex)) induced by the thermal Sunyaev-Zel'dovich (tSZ) effect in filtered Atacama Cosmology Telescope (ACT) 148 GHz cosmic microwave background temperature maps. Contamination due to infrared and radio sources is minimized by template subtraction of resolved sources and by constructing a mask using outlying values in the 218 GHz (tSZ-null) ACT maps. We measure (T(sup )(sup 3) (n(circumflex)) = -31 plus or minus 6 micro-K(sup 3) (measurement error only) or plus or minus 14 micro-K(sup 3) (including cosmic variance error) in the filtered ACT data, a 5sigma detection. We show that the skewness is a sensitive probe of sigma(sub 8), and use analytic calculations and tSZ simulations to obtain cosmological constraints from this measurement. From this signal alone we infer a value of sigma(sub 8) = 0.78 sup +0.03 sub -0.04 (68% C.L.) sup +0.05 sub -0.16. Our results demonstrate that measurements of nonGaussianity can be a useful method for characterizing the tSZ effect and extracting the underlying cosmological information.

  11. Quantitative analysis of replication-related mutation and selection pressures in bacterial chromosomes and plasmids using generalised GC skew index

    Directory of Open Access Journals (Sweden)

    Suzuki Haruo

    2009-12-01

    Full Text Available Abstract Background Due to their bi-directional replication machinery starting from a single finite origin, bacterial genomes show characteristic nucleotide compositional bias between the two replichores, which can be visualised through GC skew or (C-G/(C+G. Although this polarisation is used for computational prediction of replication origins in many bacterial genomes, the degree of GC skew visibility varies widely among different species, necessitating a quantitative measurement of GC skew strength in order to provide confidence measures for GC skew-based predictions of replication origins. Results Here we discuss a quantitative index for the measurement of GC skew strength, named the generalised GC skew index (gGCSI, which is applicable to genomes of any length, including bacterial chromosomes and plasmids. We demonstrate that gGCSI is independent of the window size and can thus be used to compare genomes with different sizes, such as bacterial chromosomes and plasmids. It can suggest the existence of different replication mechanisms in archaea and of rolling-circle replication in plasmids. Correlation of gGCSI values between plasmids and their corresponding host chromosomes suggests that within the same strain, these replicons have reproduced using the same replication machinery and thus exhibit similar strengths of replication strand skew. Conclusions gGCSI can be applied to genomes of any length and thus allows comparative study of replication-related mutation and selection pressures in genomes of different lengths such as bacterial chromosomes and plasmids. Using gGCSI, we showed that replication-related mutation or selection pressure is similar for replicons with similar machinery.

  12. Repatriation Adjustment: Literature Review

    Directory of Open Access Journals (Sweden)

    Gamze Arman

    2009-12-01

    Full Text Available Expatriation is a widely studied area of research in work and organizational psychology. After expatriates accomplish their missions in host countries, they return to their countries and this process is called repatriation. Adjustment constitutes a crucial part in repatriation research. In the present literature review, research about repatriation adjustment was reviewed with the aim of defining the whole picture in this phenomenon. Present research was classified on the basis of a theoretical model of repatriation adjustment. Basic frame consisted of antecedents, adjustment, outcomes as main variables and personal characteristics/coping strategies and organizational strategies as moderating variables.

  13. Different male versus female breeding periodicity helps mitigate offspring sex ratio skews in sea turtles

    Directory of Open Access Journals (Sweden)

    Graeme Clive Hays

    2014-09-01

    Full Text Available The implications of climate change for global biodiversity may be profound with those species with little capacity for adaptation being thought to be particularly vulnerable to warming. A classic case of groups for concern are those animals exhibiting temperature-dependent sex-determination (TSD, such as sea turtles, where climate warming may produce single sex populations and hence extinction. We show that, globally, female biased hatchling sex ratios dominate sea turtle populations (exceeding 3:1 in >50% records, which, at-a-glance, reiterates concerns for extinction. However, we also demonstrate that more frequent breeding by males, empirically shown by satellite tracking 23 individuals and supported by a generalized bio-energetic life history model, generates more balanced operational sex ratios (OSRs. Hence, concerns of increasingly skewed hatchling sex ratios and reduced population viability are less acute than previously thought for sea turtles. In fact, in some scenarios skewed hatchling sex ratios in groups with TSD may be adaptive to ensure optimum OSRs.

  14. Robust bivariate error detection in skewed data with application to historical radiosonde winds

    KAUST Repository

    Sun, Ying

    2017-01-18

    The global historical radiosonde archives date back to the 1920s and contain the only directly observed measurements of temperature, wind, and moisture in the upper atmosphere, but they contain many random errors. Most of the focus on cleaning these large datasets has been on temperatures, but winds are important inputs to climate models and in studies of wind climatology. The bivariate distribution of the wind vector does not have elliptical contours but is skewed and heavy-tailed, so we develop two methods for outlier detection based on the bivariate skew-t (BST) distribution, using either distance-based or contour-based approaches to flag observations as potential outliers. We develop a framework to robustly estimate the parameters of the BST and then show how the tuning parameter to get these estimates is chosen. In simulation, we compare our methods with one based on a bivariate normal distribution and a nonparametric approach based on the bagplot. We then apply all four methods to the winds observed for over 35,000 radiosonde launches at a single station and demonstrate differences in the number of observations flagged across eight pressure levels and through time. In this pilot study, the method based on the BST contours performs very well.

  15. Understanding the distinctively skewed and heavy tailed character of atmospheric and oceanic probability distributions

    Energy Technology Data Exchange (ETDEWEB)

    Sardeshmukh, Prashant D., E-mail: Prashant.D.Sardeshmukh@noaa.gov [CIRES, University of Colorado, Boulder, Colorado 80309 (United States); NOAA/Earth System Research Laboratory, Boulder, Colorado 80305 (United States); Penland, Cécile [NOAA/Earth System Research Laboratory, Boulder, Colorado 80305 (United States)

    2015-03-15

    The probability distributions of large-scale atmospheric and oceanic variables are generally skewed and heavy-tailed. We argue that their distinctive departures from Gaussianity arise fundamentally from the fact that in a quadratically nonlinear system with a quadratic invariant, the coupling coefficients between system components are not constant but depend linearly on the system state in a distinctive way. In particular, the skewness arises from a tendency of the system trajectory to linger near states of weak coupling. We show that the salient features of the observed non-Gaussianity can be captured in the simplest such nonlinear 2-component system. If the system is stochastically forced and linearly damped, with one component damped much more strongly than the other, then the strongly damped fast component becomes effectively decoupled from the weakly damped slow component, and its impact on the slow component can be approximated as a stochastic noise forcing plus an augmented nonlinear damping. In the limit of large time-scale separation, the nonlinear augmentation of the damping becomes small, and the noise forcing can be approximated as an additive noise plus a correlated additive and multiplicative noise (CAM noise) forcing. Much of the diversity of observed large-scale atmospheric and oceanic probability distributions can be interpreted in this minimal framework.

  16. Fecal bacteria from treatment-naive Crohn's disease patients can skew helper T cell responses.

    Science.gov (United States)

    Ma, Fei; Zhang, Yi; Xing, Junjie; Song, Xiaoling; Huang, Ling; Weng, Hao; Wu, Xiangsong; Walker, Emma; Wang, Zhongchuan

    2017-12-01

    Many studies have demonstrated that the inflamed mucosa of Crohn's disease (CD) patients presented a disturbed gut commensal community, and the shift in microbial composition and species variety is associated with disease severity. To establish a link between changes in the intestinal bacterial composition and the alteration of inflammation, we obtained fecal bacteria from CD patients and non-CD controls. The bacteria were then used to stimulate the peripheral blood mononuclear cells (PBMCs) from one non-CD individual. We found that the frequency of IFN-γ- and IL-17-expressing CD4 T cells was significantly higher after stimulation with CD bacteria than with non-CD bacteria, while the frequency of IL-4- and IL-10-expressing CD4 T cells was significantly decreased after stimulation with CD bacteria. A similar trend was observed in the level of cytokine expression and transcription expression. However, this difference was not clear-cut, as overlapping regions were observed between the two groups. With longer stimulation using CD bacteria, the skewing toward Th1/Th17 responses were further increased. This increase depended on the presence of monocytes/macrophages. Interestingly, we also found that B cells presented an inhibitory effect in CD bacteria-mediated skewing toward Th1/Th17 cells and promoted IL-10 secretion in CD bacteria-stimulated PBMCs. Together, our results demonstrated that CD bacteria could promote Th1/Th17 inflammation in a host factor-independent fashion. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Robust bivariate error detection in skewed data with application to historical radiosonde winds

    KAUST Repository

    Sun, Ying; Hering, Amanda S.; Browning, Joshua M.

    2017-01-01

    The global historical radiosonde archives date back to the 1920s and contain the only directly observed measurements of temperature, wind, and moisture in the upper atmosphere, but they contain many random errors. Most of the focus on cleaning these large datasets has been on temperatures, but winds are important inputs to climate models and in studies of wind climatology. The bivariate distribution of the wind vector does not have elliptical contours but is skewed and heavy-tailed, so we develop two methods for outlier detection based on the bivariate skew-t (BST) distribution, using either distance-based or contour-based approaches to flag observations as potential outliers. We develop a framework to robustly estimate the parameters of the BST and then show how the tuning parameter to get these estimates is chosen. In simulation, we compare our methods with one based on a bivariate normal distribution and a nonparametric approach based on the bagplot. We then apply all four methods to the winds observed for over 35,000 radiosonde launches at a single station and demonstrate differences in the number of observations flagged across eight pressure levels and through time. In this pilot study, the method based on the BST contours performs very well.

  18. Hölder properties of perturbed skew products and Fubini regained

    International Nuclear Information System (INIS)

    Ilyashenko, Yu; Negut, A

    2012-01-01

    In 2006, Gorodetski proved that central fibres of perturbed skew products are Hölder continuous with respect to the base point. In this paper, we give an explicit estimate of this Hölder exponent. Moreover, we extend Gorodetski's result from the case when the fibre maps are close to the identity to a much wider class of maps that satisfy the so-called modified dominated splitting condition. In many cases (for example, in the case of skew products over the solenoid or over linear Anosov diffeomorphisms of the torus), the Hölder exponent is close to 1. This allows one to overcome the so-called Fubini nightmare, in some sense. Namely, we prove that the union of central fibres that are strongly atypical from the point of view of ergodic theory, has Lebesgue measure zero despite the lack of absolute continuity of the holonomy map for the central foliation. This result is based on a new kind of ergodic theorem, which we call special. To prove our main result, we revisit the theory of Hirsch, Pugh and Shub, and estimate the contraction constant of the graph transform map. (paper)

  19. Fuel cell plates with skewed process channels for uniform distribution of stack compression load

    Science.gov (United States)

    Granata, Jr., Samuel J.; Woodle, Boyd M.

    1989-01-01

    An electrochemical fuel cell includes an anode electrode, a cathode electrode, an electrolyte matrix sandwiched between electrodes, and a pair of plates above and below the electrodes. The plate above the electrodes has a lower surface with a first group of process gas flow channels formed thereon and the plate below the electrodes has an upper surface with a second group of process gas flow channels formed thereon. The channels of each group extend generally parallel to one another. The improvement comprises the process gas flow channels on the lower surface of the plate above the anode electrode and the process gas flow channels on the upper surface of the plate below the cathode electrode being skewed in opposite directions such that contact areas of the surfaces of the plates through the electrodes are formed in crisscross arrangements. Also, the plates have at least one groove in areas of the surfaces thereof where the channels are absent for holding process gas and increasing electrochemical activity of the fuel cell. The groove in each plate surface intersects with the process channels therein. Also, the opposite surfaces of a bipolar plate for a fuel cell contain first and second arrangements of process gas flow channels in the respective surfaces which are skewed the same amount in opposite directions relative to the longitudinal centerline of the plate.

  20. Highly Efficient, Zero-Skew, Integrated Clock Distribution Networks Using Salphasic Principles

    Directory of Open Access Journals (Sweden)

    PASCA, A.

    2016-02-01

    Full Text Available The design of highly efficient clock distributions for integrated circuits is an active topic of research as there will never be a single solution for all systems. For high performance digital or mixed-signal circuits, achieving zero-skew clock over large areas usually comes with high costs in power requirements and design complexity. The present paper shows an overview of a recently proposed technique for ICs - on-die salphasic clock distribution, introduced by the author for CMOS processes. Initially reported in literature for rack-systems, the present paper shows that further refinements are needed for the concept to be applicable on a silicon die. Based on the formation of a standing wave (intrinsically presenting extended in-phase regions with a voltage peak at the input (creating a no-load condition, it is shown that any IC implementation must use transmission lines loss compensation techniques to maintain the proper standing wave configuration. Furthermore, the paper shows theoretical solutions and describes practical on-die techniques for pseudo-spherical bidimensional surfaces, which, with the already reported orthogonal and pseudo-orthogonal structures, can be used to distribute with minimal power requirements a zero-skew clock signal, over large silicon areas.

  1. Invariant graphs of a family of non-uniformly expanding skew products over Markov maps

    Science.gov (United States)

    Walkden, C. P.; Withers, T.

    2018-06-01

    We consider a family of skew-products of the form where T is a continuous, expanding, locally eventually onto Markov map and is a family of homeomorphisms of . A function is said to be an invariant graph if is an invariant set for the skew-product; equivalently, u(T(x))  =  g x (u(x)). A well-studied problem is to consider the existence, regularity and dimension-theoretic properties of such functions, usually under strong contraction or expansion conditions (in terms of Lyapunov exponents or partial hyperbolicity) in the fibre direction. Here we consider such problems in a setting where the Lyapunov exponent in the fibre direction is zero on a set of periodic orbits but expands except on a neighbourhood of these periodic orbits. We prove that u either has the structure of a ‘quasi-graph’ (or ‘bony graph’) or is as smooth as the dynamics, and we give a criteria for this to happen.

  2. Differential properties and attracting sets of a simplest skew product of interval maps

    International Nuclear Information System (INIS)

    Efremova, Lyudmila S

    2010-01-01

    For a skew product of interval maps with a closed set of periodic points, the dependence of the structure of its ω-limit sets on its differential properties is investigated. An example of a map in this class is constructed which has the maximal differentiability properties (within a certain subclass) with respect to the variable x, is C 1 -smooth in the y-variable and has one-dimensional ω-limit sets. Theorems are proved that give necessary conditions for one-dimensional ω-limit sets to exist. One of them is formulated in terms of the divergence of the series consisting of the values of a function of x; this function is the C 0 -norm of the deviation of the restrictions of the fibre maps to some nondegenerate closed interval from the identity on the same interval. Another theorem is formulated in terms of the properties of the partial derivative with respect to x of the fibre maps. A complete description is given of the ω-limit sets of certain class of C 1 -smooth skew products satisfying some natural conditions. Bibliography: 33 titles.

  3. Enhancing tumor apparent diffusion coefficient histogram skewness stratifies the postoperative survival in recurrent glioblastoma multiforme patients undergoing salvage surgery.

    Science.gov (United States)

    Zolal, Amir; Juratli, Tareq A; Linn, Jennifer; Podlesek, Dino; Sitoci Ficici, Kerim Hakan; Kitzler, Hagen H; Schackert, Gabriele; Sobottka, Stephan B; Rieger, Bernhard; Krex, Dietmar

    2016-05-01

    Objective To determine the value of apparent diffusion coefficient (ADC) histogram parameters for the prediction of individual survival in patients undergoing surgery for recurrent glioblastoma (GBM) in a retrospective cohort study. Methods Thirty-one patients who underwent surgery for first recurrence of a known GBM between 2008 and 2012 were included. The following parameters were collected: age, sex, enhancing tumor size, mean ADC, median ADC, ADC skewness, ADC kurtosis and fifth percentile of the ADC histogram, initial progression free survival (PFS), extent of second resection and further adjuvant treatment. The association of these parameters with survival and PFS after second surgery was analyzed using log-rank test and Cox regression. Results Using log-rank test, ADC histogram skewness of the enhancing tumor was significantly associated with both survival (p = 0.001) and PFS after second surgery (p = 0.005). Further parameters associated with prolonged survival after second surgery were: gross total resection at second surgery (p = 0.026), tumor size (0.040) and third surgery (p = 0.003). In the multivariate Cox analysis, ADC histogram skewness was shown to be an independent prognostic factor for survival after second surgery. Conclusion ADC histogram skewness of the enhancing lesion, enhancing lesion size, third surgery, as well as gross total resection have been shown to be associated with survival following the second surgery. ADC histogram skewness was an independent prognostic factor for survival in the multivariate analysis.

  4. Bayesian inference for two-part mixed-effects model using skew distributions, with application to longitudinal semicontinuous alcohol data.

    Science.gov (United States)

    Xing, Dongyuan; Huang, Yangxin; Chen, Henian; Zhu, Yiliang; Dagne, Getachew A; Baldwin, Julie

    2017-08-01

    Semicontinuous data featured with an excessive proportion of zeros and right-skewed continuous positive values arise frequently in practice. One example would be the substance abuse/dependence symptoms data for which a substantial proportion of subjects investigated may report zero. Two-part mixed-effects models have been developed to analyze repeated measures of semicontinuous data from longitudinal studies. In this paper, we propose a flexible two-part mixed-effects model with skew distributions for correlated semicontinuous alcohol data under the framework of a Bayesian approach. The proposed model specification consists of two mixed-effects models linked by the correlated random effects: (i) a model on the occurrence of positive values using a generalized logistic mixed-effects model (Part I); and (ii) a model on the intensity of positive values using a linear mixed-effects model where the model errors follow skew distributions including skew- t and skew-normal distributions (Part II). The proposed method is illustrated with an alcohol abuse/dependence symptoms data from a longitudinal observational study, and the analytic results are reported by comparing potential models under different random-effects structures. Simulation studies are conducted to assess the performance of the proposed models and method.

  5. ADJUSTABLE CHIP HOLDER

    DEFF Research Database (Denmark)

    2009-01-01

    An adjustable microchip holder for holding a microchip is provided having a plurality of displaceable interconnection pads for connecting the connection holes of a microchip with one or more external devices or equipment. The adjustable microchip holder can fit different sizes of microchips...

  6. Auto-Calibration and Fault Detection and Isolation of Skewed Redundant Accelerometers in Measurement While Drilling Systems.

    Science.gov (United States)

    Seyed Moosavi, Seyed Mohsen; Moaveni, Bijan; Moshiri, Behzad; Arvan, Mohammad Reza

    2018-02-27

    The present study designed skewed redundant accelerometers for a Measurement While Drilling (MWD) tool and executed auto-calibration, fault diagnosis and isolation of accelerometers in this tool. The optimal structure includes four accelerometers was selected and designed precisely in accordance with the physical shape of the existing MWD tool. A new four-accelerometer structure was designed, implemented and installed on the current system, replacing the conventional orthogonal structure. Auto-calibration operation of skewed redundant accelerometers and all combinations of three accelerometers have been done. Consequently, biases, scale factors, and misalignment factors of accelerometers have been successfully estimated. By defecting the sensors in the new optimal skewed redundant structure, the fault was detected using the proposed FDI method and the faulty sensor was diagnosed and isolated. The results indicate that the system can continue to operate with at least three correct sensors.

  7. Auto-Calibration and Fault Detection and Isolation of Skewed Redundant Accelerometers in Measurement While Drilling Systems

    Directory of Open Access Journals (Sweden)

    Seyed Mohsen Seyed Moosavi

    2018-02-01

    Full Text Available The present study designed skewed redundant accelerometers for a Measurement While Drilling (MWD tool and executed auto-calibration, fault diagnosis and isolation of accelerometers in this tool. The optimal structure includes four accelerometers was selected and designed precisely in accordance with the physical shape of the existing MWD tool. A new four-accelerometer structure was designed, implemented and installed on the current system, replacing the conventional orthogonal structure. Auto-calibration operation of skewed redundant accelerometers and all combinations of three accelerometers have been done. Consequently, biases, scale factors, and misalignment factors of accelerometers have been successfully estimated. By defecting the sensors in the new optimal skewed redundant structure, the fault was detected using the proposed FDI method and the faulty sensor was diagnosed and isolated. The results indicate that the system can continue to operate with at least three correct sensors.

  8. Low reproductive skew despite high male-biased operational sex ratio in a glass frog with paternal care.

    Science.gov (United States)

    Mangold, Alexandra; Trenkwalder, Katharina; Ringler, Max; Hödl, Walter; Ringler, Eva

    2015-09-03

    Reproductive skew, the uneven distribution of reproductive success among individuals, is a common feature of many animal populations. Several scenarios have been proposed to favour either high or low levels of reproductive skew. Particularly a male-biased operational sex ratio and the asynchronous arrival of females is expected to cause high variation in reproductive success among males. Recently it has been suggested that the type of benefits provided by males (fixed vs. dilutable) could also strongly impact individual mating patterns, and thereby affecting reproductive skew. We tested this hypothesis in Hyalinobatrachium valerioi, a Neotropical glass frog with prolonged breeding and paternal care. We monitored and genetically sampled a natural population in southwestern Costa Rica during the breeding season in 2012 and performed parentage analysis of adult frogs and tadpoles to investigate individual mating frequencies, possible mating preferences, and estimate reproductive skew in males and females. We identified a polygamous mating system, where high proportions of males (69 %) and females (94 %) reproduced successfully. The variance in male mating success could largely be attributed to differences in time spent calling at the reproductive site, but not to body size or relatedness. Female H. valerioi were not choosy and mated indiscriminately with available males. Our findings support the hypothesis that dilutable male benefits - such as parental care - can favour female polyandry and maintain low levels of reproductive skew among males within a population, even in the presence of direct male-male competition and a highly male-biased operational sex ratio. We hypothesize that low male reproductive skew might be a general characteristic in prolonged breeders with paternal care.

  9. Skewed Marriage Markets and Sex Ratios of Finnish People in their Twenties

    Directory of Open Access Journals (Sweden)

    Lassi Lainiala

    2014-03-01

    Full Text Available This article studies variation in regional sex ratios in Finland and outlines potential implications of the skewed sex ratios for family formation patterns. Difficulties in finding a suitable partner are typically mentioned as one of the most important reasons for remaining childless, and we explore if this reason is apparent structurally at the regional macro level. We found significant variation in sex ratios in age-groups 18–30 at the regional and sub-regional levels. Of the whole 20–29-year old population in Finland, almost 50 percent live in sub-region areas with a male surplus. As expected, a higher proportion of men compared to women appears to increase fertility of women in younger age groups. Contrary to expectations, high male-female ratios were not related to higher proportion of women living with a partner

  10. B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction.

    Science.gov (United States)

    Shin, Jung Hoon; Park, Se-Ho

    2013-10-01

    CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although α-galactosylceramide (α-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-γ by NKT cells, concomitant with a decreased level of IL-4, in the circumstance of co-culture of DCs and B Cells. Remarkably, the response promoted by B cells was dependent on CD1d expression of B cells.

  11. Bed slope effects on turbulent wave boundary layers: 2. Comparison with skewness, asymmetry, and other effects

    DEFF Research Database (Denmark)

    Fuhrman, David R.; Fredsøe, Jørgen; Sumer, B. Mutlu

    2009-01-01

    currents or undertow). The effects from each of the four components are isolated and quantified using a standard set of bed shear stress quantities, allowing their easy comparison. For conditions representing large shallow-water waves on steep slopes, the results suggest that converging-diverging effects......A numerical model solving incompressible Reynolds-averaged Navier-Stokes equations, combined with a two-equation k-omega model for turbulence closure, is used to systematically compare the relative strength of bed shear stress quantities and boundary layer streaming under wave motions from four...... from beach slope may make a significant onshore bed load contribution. Generally, however, the results suggest wave skewness (in addition to conventional steady streaming) as the most important onshore contribution outside the surf zone. Streaming induced within the wave boundary layer is also...

  12. Assessing Potential Wind Energy Resources in Saudi Arabia with a Skew-t Distribution

    KAUST Repository

    Tagle, Felipe

    2017-03-13

    Facing increasing domestic energy consumption from population growth and industrialization, Saudi Arabia is aiming to reduce its reliance on fossil fuels and to broaden its energy mix by expanding investment in renewable energy sources, including wind energy. A preliminary task in the development of wind energy infrastructure is the assessment of wind energy potential, a key aspect of which is the characterization of its spatio-temporal behavior. In this study we examine the impact of internal climate variability on seasonal wind power density fluctuations using 30 simulations from the Large Ensemble Project (LENS) developed at the National Center for Atmospheric Research. Furthermore, a spatio-temporal model for daily wind speed is proposed with neighbor-based cross-temporal dependence, and a multivariate skew-t distribution to capture the spatial patterns of higher order moments. The model can be used to generate synthetic time series over the entire spatial domain that adequately reproduces the internal variability of the LENS dataset.

  13. A novel generalized normal distribution for human longevity and other negatively skewed data.

    Science.gov (United States)

    Robertson, Henry T; Allison, David B

    2012-01-01

    Negatively skewed data arise occasionally in statistical practice; perhaps the most familiar example is the distribution of human longevity. Although other generalizations of the normal distribution exist, we demonstrate a new alternative that apparently fits human longevity data better. We propose an alternative approach of a normal distribution whose scale parameter is conditioned on attained age. This approach is consistent with previous findings that longevity conditioned on survival to the modal age behaves like a normal distribution. We derive such a distribution and demonstrate its accuracy in modeling human longevity data from life tables. The new distribution is characterized by 1. An intuitively straightforward genesis; 2. Closed forms for the pdf, cdf, mode, quantile, and hazard functions; and 3. Accessibility to non-statisticians, based on its close relationship to the normal distribution.

  14. Assessing Potential Wind Energy Resources in Saudi Arabia with a Skew-t Distribution

    KAUST Repository

    Tagle, Felipe; Castruccio, Stefano; Crippa, Paola; Genton, Marc G.

    2017-01-01

    Facing increasing domestic energy consumption from population growth and industrialization, Saudi Arabia is aiming to reduce its reliance on fossil fuels and to broaden its energy mix by expanding investment in renewable energy sources, including wind energy. A preliminary task in the development of wind energy infrastructure is the assessment of wind energy potential, a key aspect of which is the characterization of its spatio-temporal behavior. In this study we examine the impact of internal climate variability on seasonal wind power density fluctuations using 30 simulations from the Large Ensemble Project (LENS) developed at the National Center for Atmospheric Research. Furthermore, a spatio-temporal model for daily wind speed is proposed with neighbor-based cross-temporal dependence, and a multivariate skew-t distribution to capture the spatial patterns of higher order moments. The model can be used to generate synthetic time series over the entire spatial domain that adequately reproduces the internal variability of the LENS dataset.

  15. Separation of variables in anisotropic models and non-skew-symmetric elliptic r-matrix

    Science.gov (United States)

    Skrypnyk, Taras

    2017-05-01

    We solve a problem of separation of variables for the classical integrable hamiltonian systems possessing Lax matrices satisfying linear Poisson brackets with the non-skew-symmetric, non-dynamical elliptic so(3)⊗ so(3)-valued classical r-matrix. Using the corresponding Lax matrices, we present a general form of the "separating functions" B( u) and A( u) that generate the coordinates and the momenta of separation for the associated models. We consider several examples and perform the separation of variables for the classical anisotropic Euler's top, Steklov-Lyapunov model of the motion of anisotropic rigid body in the liquid, two-spin generalized Gaudin model and "spin" generalization of Steklov-Lyapunov model.

  16. Adjusting estimative prediction limits

    OpenAIRE

    Masao Ueki; Kaoru Fueda

    2007-01-01

    This note presents a direct adjustment of the estimative prediction limit to reduce the coverage error from a target value to third-order accuracy. The adjustment is asymptotically equivalent to those of Barndorff-Nielsen & Cox (1994, 1996) and Vidoni (1998). It has a simpler form with a plug-in estimator of the coverage probability of the estimative limit at the target value. Copyright 2007, Oxford University Press.

  17. Adjustable Pitot Probe

    Science.gov (United States)

    Ashby, George C., Jr.; Robbins, W. Eugene; Horsley, Lewis A.

    1991-01-01

    Probe readily positionable in core of uniform flow in hypersonic wind tunnel. Formed of pair of mating cylindrical housings: transducer housing and pitot-tube housing. Pitot tube supported by adjustable wedge fairing attached to top of pitot-tube housing with semicircular foot. Probe adjusted both radially and circumferentially. In addition, pressure-sensing transducer cooled internally by water or other cooling fluid passing through annulus of cooling system.

  18. Low paternity skew and the influence of maternal kin in an egalitarian, patrilocal primate.

    Science.gov (United States)

    Strier, Karen B; Chaves, Paulo B; Mendes, Sérgio L; Fagundes, Valéria; Di Fiore, Anthony

    2011-11-22

    Levels of reproductive skew vary in wild primates living in multimale groups depending on the degree to which high-ranking males monopolize access to females. Still, the factors affecting paternity in egalitarian societies remain unexplored. We combine unique behavioral, life history, and genetic data to evaluate the distribution of paternity in the northern muriqui (Brachyteles hypoxanthus), a species known for its affiliative, nonhierarchical relationships. We genotyped 67 individuals (22 infants born over a 3-y period, their 21 mothers, and all 24 possible sires) at 17 microsatellite marker loci and assigned paternity to all infants. None of the 13 fathers were close maternal relatives of females with which they sired infants, and the most successful male sired a much lower percentage of infants (18%) than reported for the most successful males in other species. Our findings of inbreeding avoidance and low male reproductive skew are consistent with the muriqui's observed social and sexual behavior, but the long delay (≥2.08 y) between the onset of male sexual behavior and the age at which males first sire young is unexpected. The allocation of paternity implicates individual male life histories and access to maternal kin as key factors influencing variation in paternal--and grandmaternal--fitness. The apparent importance of lifelong maternal investment in coresident sons resonates with other recent examinations of maternal influences on offspring reproduction. This importance also extends the implications of the "grandmother hypothesis" in human evolution to include the possible influence of mothers and other maternal kin on male reproductive success in patrilocal societies.

  19. Th1-skewed tissue responses to a mycolyl glycolipid in mycobacteria-infected rhesus macaques

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Daisuke; Miyamoto, Ayumi; Hattori, Yuki; Komori, Takaya [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Nakamura, Takashi [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Igarashi, Tatsuhiko [Laboratory of Primate Model, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Harashima, Hideyoshi [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Sugita, Masahiko [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan)

    2013-11-08

    Highlights: •Glucose monomycolate (GMM) is a marker glycolipid for active tuberculosis. •Tissue responses to GMM involved up-regulation of Th1-attracting chemokines. •Th1-skewed local responses were mounted at the GMM-injected tissue. -- Abstract: Trehalose 6,6′-dimycolate (TDM) is a major glycolipid of the cell wall of mycobacteria with remarkable adjuvant functions. To avoid detection by the host innate immune system, invading mycobacteria down-regulate the expression of TDM by utilizing host-derived glucose as a competitive substrate for their mycolyltransferases; however, this enzymatic reaction results in the concomitant biosynthesis of glucose monomycolate (GMM) which is recognized by the acquired immune system. GMM-specific, CD1-restricted T cell responses have been detected in the peripheral blood of infected human subjects and monkeys as well as in secondary lymphoid organs of small animals, such as guinea pigs and human CD1-transgenic mice. Nevertheless, it remains to be determined how tissues respond at the site where GMM is produced. Here we found that rhesus macaques vaccinated with Mycobacterium bovis bacillus Calmette–Guerin mounted a chemokine response in GMM-challenged skin that was favorable for recruiting T helper (Th)1 T cells. Indeed, the expression of interferon-γ, but not Th2 or Th17 cytokines, was prominent in the GMM-injected tissue. The GMM-elicited tissue response was also associated with the expression of monocyte/macrophage-attracting CC chemokines, such as CCL2, CCL4 and CCL8. Furthermore, the skin response to GMM involved the up-regulated expression of granulysin and perforin. Given that GMM is produced primarily by pathogenic mycobacteria proliferating within the host, the Th1-skewed tissue response to GMM may function efficiently at the site of infection.

  20. Th1-skewed tissue responses to a mycolyl glycolipid in mycobacteria-infected rhesus macaques

    International Nuclear Information System (INIS)

    Morita, Daisuke; Miyamoto, Ayumi; Hattori, Yuki; Komori, Takaya; Nakamura, Takashi; Igarashi, Tatsuhiko; Harashima, Hideyoshi; Sugita, Masahiko

    2013-01-01

    Highlights: •Glucose monomycolate (GMM) is a marker glycolipid for active tuberculosis. •Tissue responses to GMM involved up-regulation of Th1-attracting chemokines. •Th1-skewed local responses were mounted at the GMM-injected tissue. -- Abstract: Trehalose 6,6′-dimycolate (TDM) is a major glycolipid of the cell wall of mycobacteria with remarkable adjuvant functions. To avoid detection by the host innate immune system, invading mycobacteria down-regulate the expression of TDM by utilizing host-derived glucose as a competitive substrate for their mycolyltransferases; however, this enzymatic reaction results in the concomitant biosynthesis of glucose monomycolate (GMM) which is recognized by the acquired immune system. GMM-specific, CD1-restricted T cell responses have been detected in the peripheral blood of infected human subjects and monkeys as well as in secondary lymphoid organs of small animals, such as guinea pigs and human CD1-transgenic mice. Nevertheless, it remains to be determined how tissues respond at the site where GMM is produced. Here we found that rhesus macaques vaccinated with Mycobacterium bovis bacillus Calmette–Guerin mounted a chemokine response in GMM-challenged skin that was favorable for recruiting T helper (Th)1 T cells. Indeed, the expression of interferon-γ, but not Th2 or Th17 cytokines, was prominent in the GMM-injected tissue. The GMM-elicited tissue response was also associated with the expression of monocyte/macrophage-attracting CC chemokines, such as CCL2, CCL4 and CCL8. Furthermore, the skin response to GMM involved the up-regulated expression of granulysin and perforin. Given that GMM is produced primarily by pathogenic mycobacteria proliferating within the host, the Th1-skewed tissue response to GMM may function efficiently at the site of infection

  1. Phenotypic analysis of prostate-infiltrating lymphocytes reveals TH17 and Treg skewing.

    Science.gov (United States)

    Sfanos, Karen Sandell; Bruno, Tullia C; Maris, Charles H; Xu, Lauren; Thoburn, Christopher J; DeMarzo, Angelo M; Meeker, Alan K; Isaacs, William B; Drake, Charles G

    2008-06-01

    Pathologic examination of prostate glands removed from patients with prostate cancer commonly reveals infiltrating CD4+ and CD8+ T cells. Little is known about the phenotype of these cells, despite accumulating evidence suggesting a potential role for chronic inflammation in the etiology of prostate cancer. We developed a technique that samples the majority of the peripheral prostate through serial needle aspirates. CD4+ prostate-infiltrating lymphocytes (PIL) were isolated using magnetic beads and analyzed for subset skewing using both flow cytometry and quantitative reverse transcription-PCR. The transcriptional profile of fluorescence-activated cell sorted prostate-infiltrating regulatory T cells (CD4+, CD25+, GITR+) was compared with naïve, peripheral blood T cells using microarray analysis. CD4+ PIL showed a paucity of TH2 (interleukin-4-secreting) cells, a surprising finding given the generally accepted association of these cells with chronic, smoldering inflammation. Instead, CD4+ PIL seemed to be skewed towards a regulatory Treg phenotype (FoxP3+) as well as towards the TH17 phenotype (interleukin-17+). We also found that a preponderance of TH17-mediated inflammation was associated with a lower pathologic Gleason score. These protein level data were reflected at the message level, as analyzed by quantitative reverse transcription-PCR. Microarray analysis of pooled prostate-infiltrating T(reg) revealed expected Treg-associated transcripts (FoxP3, CTLA-4, GITR, LAG-3) as well as a number of unique cell surface markers that may serve as additional Treg markers. Taken together, these data suggest that TH17 and/or Treg CD4+ T cells (rather than TH2 T cells) may be involved in the development or progression of prostate cancer.

  2. Measurement of the Width and Skewness of Elliptic Flow Fluctuations in PbPb Collisions at 5.02 TeV with CMS

    Science.gov (United States)

    Castle, James R.; CMS Collaboration

    2017-11-01

    Flow harmonic fluctuations are studied for PbPb collisions at √{sNN} = 5.02 TeV using the CMS detector at the LHC. Flow harmonic probability distributions p(v2) are obtained by unfolding smearing effects from observed azimuthal anisotropy distributions using particles of 0.3 statistically significant negative skewness is observed for all centrality bins as evidenced by a splitting between v2 {4}, v2 {6}, and v2 {8} cumulants. Elliptic power law distribution fits are made to p(v2) distributions to infer information on the nature of initial-state eccentricity distributions and found to provide a more accurate description of the fluctuations than a Bessel-Gaussian parametrization.

  3. Comparison of linear, skewed-linear, and proportional hazard models for the analysis of lambing interval in Ripollesa ewes.

    Science.gov (United States)

    Casellas, J; Bach, R

    2012-06-01

    Lambing interval is a relevant reproductive indicator for sheep populations under continuous mating systems, although there is a shortage of selection programs accounting for this trait in the sheep industry. Both the historical assumption of small genetic background and its unorthodox distribution pattern have limited its implementation as a breeding objective. In this manuscript, statistical performances of 3 alternative parametrizations [i.e., symmetric Gaussian mixed linear (GML) model, skew-Gaussian mixed linear (SGML) model, and piecewise Weibull proportional hazard (PWPH) model] have been compared to elucidate the preferred methodology to handle lambing interval data. More specifically, flock-by-flock analyses were performed on 31,986 lambing interval records (257.3 ± 0.2 d) from 6 purebred Ripollesa flocks. Model performances were compared in terms of deviance information criterion (DIC) and Bayes factor (BF). For all flocks, PWPH models were clearly preferred; they generated a reduction of 1,900 or more DIC units and provided BF estimates larger than 100 (i.e., PWPH models against linear models). These differences were reduced when comparing PWPH models with different number of change points for the baseline hazard function. In 4 flocks, only 2 change points were required to minimize the DIC, whereas 4 and 6 change points were needed for the 2 remaining flocks. These differences demonstrated a remarkable degree of heterogeneity across sheep flocks that must be properly accounted for in genetic evaluation models to avoid statistical biases and suboptimal genetic trends. Within this context, all 6 Ripollesa flocks revealed substantial genetic background for lambing interval with heritabilities ranging between 0.13 and 0.19. This study provides the first evidence of the suitability of PWPH models for lambing interval analysis, clearly discarding previous parametrizations focused on mixed linear models.

  4. Prediction of the moments in advection-diffusion lattice Boltzmann method. I. Truncation dispersion, skewness, and kurtosis

    Science.gov (United States)

    Ginzburg, Irina

    2017-01-01

    The effect of the heterogeneity in the soil structure or the nonuniformity of the velocity field on the modeled resident time distribution (RTD) and breakthrough curves is quantified by their moments. While the first moment provides the effective velocity, the second moment is related to the longitudinal dispersion coefficient (kT) in the developed Taylor regime; the third and fourth moments are characterized by their normalized values skewness (Sk) and kurtosis (Ku), respectively. The purpose of this investigation is to examine the role of the truncation corrections of the numerical scheme in kT, Sk, and Ku because of their interference with the second moment, in the form of the numerical dispersion, and in the higher-order moments, by their definition. Our symbolic procedure is based on the recently proposed extended method of moments (EMM). Originally, the EMM restores any-order physical moments of the RTD or averaged distributions assuming that the solute concentration obeys the advection-diffusion equation in multidimensional steady-state velocity field, in streamwise-periodic heterogeneous structure. In our work, the EMM is generalized to the fourth-order-accurate apparent mass-conservation equation in two- and three-dimensional duct flows. The method looks for the solution of the transport equation as the product of a long harmonic wave and a spatially periodic oscillating component; the moments of the given numerical scheme are derived from a chain of the steady-state fourth-order equations at a single cell. This mathematical technique is exemplified for the truncation terms of the two-relaxation-time lattice Boltzmann scheme, using plug and parabolic flow in straight channel and cylindrical capillary with the d2Q9 and d3Q15 discrete velocity sets as simple but illustrative examples. The derived symbolic dependencies can be readily extended for advection by another, Newtonian or non-Newtonian, flow profile in any-shape open-tabular conduits. It is

  5. Resonance multiphoton ionization and dissociation of dimethyl ether via the {\\skew1\\tilde{\\rm C}^{\\prime}}, {\\skew1\\tilde{\\rm C}} and \\tilde{\\rm B} states

    Science.gov (United States)

    Mejia-Ospino, E.; García, G.; Guerrero, A.; Alvarez, I.; Cisneros, C.

    2005-01-01

    The three-photon resonance four-photon ionization and dissociation spectra of dimethyl ether (DME) are presented in the wavelength range 450-550 nm at 1 nm intervals. The (3+1) REMPI spectra show three prominent bands corresponding to the \\tildeB \\leftarrow \\skew1\\tildeX, {\\skew1\\tildeC} \\leftarrow \\skew1\\tildeX and {\\skew1\\tildeC^{\\prime}} \\leftarrow \\skew1\\tildeX transitions with origins at 61 457 cm-1 (7.615 eV), 59 055 cm-1 (7.322 eV) and 58 010 cm-1 (7.194 eV), respectively. Several ionized species, CH3+, CHnO+ (n = 1-3) and CH3OCH3+, are observed in the region of wavelengths studied here. In order to compare the results, a shorter wavelength multiphoton dissociation and ionization of DME at 355 nm is also presented. At this wavelength, DME undergoes neutral dissociation to CH3 and CH3O and each fragment is then ionized by multiphoton absorption. The fragmentation at 355 nm is very intense and only small fragments such as CH3+, CHO+, CH2+, CH+ and C+ ions are observed. The measurement of photoelectron energy allows us to establish that the DME ionization potential is at least 9.55 ± 0.15 eV. The experiments were performed using a Nd:YAG-OPO (optical parametric oscillator) tunable laser system coupled to a time-of-flight mass spectrometer and a hemispherical electron energy analyser.

  6. Determining the role of skewed X-chromosome inactivation in developing muscle symptoms in carriers of Duchenne muscular dystrophy.

    Science.gov (United States)

    Viggiano, Emanuela; Ergoli, Manuela; Picillo, Esther; Politano, Luisa

    2016-07-01

    Duchenne and Becker dystrophinopathies (DMD and BMD) are X-linked recessive disorders caused by mutations in the dystrophin gene that lead to absent or reduced expression of dystrophin in both skeletal and heart muscles. DMD/BMD female carriers are usually asymptomatic, although about 8 % may exhibit muscle or cardiac symptoms. Several mechanisms leading to a reduced dystrophin have been hypothesized to explain the clinical manifestations and, in particular, the role of the skewed XCI is questioned. In this review, the mechanism of XCI and its involvement in the phenotype of BMD/DMD carriers with both a normal karyotype or with X;autosome translocations with breakpoints at Xp21 (locus of the DMD gene) will be analyzed. We have previously observed that DMD carriers with moderate/severe muscle involvement, exhibit a moderate or extremely skewed XCI, in particular if presenting with an early onset of symptoms, while DMD carriers with mild muscle involvement present a random XCI. Moreover, we found that among 87.1 % of the carriers with X;autosome translocations involving the locus Xp21 who developed signs and symptoms of dystrophinopathy such as proximal muscle weakness, difficulty to run, jump and climb stairs, 95.2 % had a skewed XCI pattern in lymphocytes. These data support the hypothesis that skewed XCI is involved in the onset of phenotype in DMD carriers, the X chromosome carrying the normal DMD gene being preferentially inactivated and leading to a moderate-severe muscle involvement.

  7. Skewed X inactivation and survival: a 13-year follow-up study of elderly twins and singletons

    DEFF Research Database (Denmark)

    Mengel-From, Jonas; Thinggaard, Mikael; Christiansen, Lene

    2012-01-01

    In mammalian females, one of the two X chromosomes is inactivated in early embryonic life. Females are therefore mosaics for two cell populations, one with the maternal and one with the paternal X as the active X chromosome. A skewed X inactivation is a marked deviation from a 50:50 ratio...... mortality than the majority of women who had a more skewed DS (hazard ratio: 1.30; 95% CI: 1.04-1.64). The association between X inactivation and mortality was replicated in dizygotic twin pairs for which the co-twin with the lowest DS also had a statistically significant tendency to die first in the twin....... In populations of women past 55-60 years of age, an increased degree of skewing (DS) is found. Here the association between age-related skewing and mortality is analyzed in a 13-year follow-up study of 500 women from three cohorts (73-100 years of age at intake). Women with low DS had significantly higher...

  8. On the Empirical Importance of the Conditional Skewness Assumption in Modelling the Relationship between Risk and Return

    Science.gov (United States)

    Pipień, M.

    2008-09-01

    We present the results of an application of Bayesian inference in testing the relation between risk and return on the financial instruments. On the basis of the Intertemporal Capital Asset Pricing Model, proposed by Merton we built a general sampling distribution suitable in analysing this relationship. The most important feature of our assumptions is that the skewness of the conditional distribution of returns is used as an alternative source of relation between risk and return. This general specification relates to Skewed Generalized Autoregressive Conditionally Heteroscedastic-in-Mean model. In order to make conditional distribution of financial returns skewed we considered the unified approach based on the inverse probability integral transformation. In particular, we applied hidden truncation mechanism, inverse scale factors, order statistics concept, Beta and Bernstein distribution transformations and also a constructive method. Based on the daily excess returns on the Warsaw Stock Exchange Index we checked the empirical importance of the conditional skewness assumption on the relation between risk and return on the Warsaw Stock Market. We present posterior probabilities of all competing specifications as well as the posterior analysis of the positive sign of the tested relationship.

  9. The role of semantics, pre-emption and skew in linguistic distributions: the case of the un-construction.

    Directory of Open Access Journals (Sweden)

    Paul eIbbotson

    2013-12-01

    Full Text Available We use the Google Ngram database, a corpus of 5,195,769 digitized books containing ~4% of all books ever published, to test three ideas that are hypothesized to account for linguistic generalizations: verbal semantics, pre-emption and skew. Using 828,813 tokens of un-forms as a test case for these mechanisms, we found verbal semantics was a good predictor of the frequency of un-forms in the English language over the past 200 years – both in terms of how the frequency changed over time and their rank frequency. We did not find strong evidence for the direct competition of un-forms and their top pre-emptors, however the skew of the un-construction competitors was inversely correlated with the acceptability of the un-form. We suggest a cognitive explanation for this, namely, that the more the set of relevant pre-emptors is skewed then the more easily it is retrieved from memory. This suggests that it is not just the frequency of pre-emptive forms that must be taken into account when trying to explain usage patterns but their skew as well.

  10. Convexity Adjustments for ATS Models

    DEFF Research Database (Denmark)

    Murgoci, Agatha; Gaspar, Raquel M.

    . As a result we classify convexity adjustments into forward adjustments and swaps adjustments. We, then, focus on affine term structure (ATS) models and, in this context, conjecture convexity adjustments should be related of affine functionals. In the case of forward adjustments, we show how to obtain exact...

  11. Sustainable urban regime adjustments

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Jensen, Jens Stissing; Elle, Morten

    2013-01-01

    The endogenous agency that urban governments increasingly portray by making conscious and planned efforts to adjust the regimes they operate within is currently not well captured in transition studies. There is a need to acknowledge the ambiguity of regime enactment at the urban scale. This direc...

  12. NPIP: A skew line needle configuration optimization system for HDR brachytherapy

    International Nuclear Information System (INIS)

    Siauw, Timmy; Cunha, Adam; Berenson, Dmitry; Atamtürk, Alper; Hsu, I-Chow; Goldberg, Ken; Pouliot, Jean

    2012-01-01

    Purpose: In this study, the authors introduce skew line needle configurations for high dose rate (HDR) brachytherapy and needle planning by integer program (NPIP), a computational method for generating these configurations. NPIP generates needle configurations that are specific to the anatomy of the patient, avoid critical structures near the penile bulb and other healthy structures, and avoid needle collisions inside the body. Methods: NPIP consisted of three major components: a method for generating a set of candidate needles, a needle selection component that chose a candidate needle subset to be inserted, and a dose planner for verifying that the final needle configuration could meet dose objectives. NPIP was used to compute needle configurations for prostate cancer data sets from patients previously treated at our clinic. NPIP took two user-parameters: a number of candidate needles, and needle coverage radius, δ. The candidate needle set consisted of 5000 needles, and a range of δ values was used to compute different needle configurations for each patient. Dose plans were computed for each needle configuration. The number of needles generated and dosimetry were analyzed and compared to the physician implant. Results: NPIP computed at least one needle configuration for every patient that met dose objectives, avoided healthy structures and needle collisions, and used as many or fewer needles than standard practice. These needle configurations corresponded to a narrow range of δ values, which could be used as default values if this system is used in practice. The average end-to-end runtime for this implementation of NPIP was 286 s, but there was a wide variation from case to case. Conclusions: The authors have shown that NPIP can automatically generate skew line needle configurations with the aforementioned properties, and that given the correct input parameters, NPIP can generate needle configurations which meet dose objectives and use as many or fewer

  13. Skew scattering dominated anomalous Hall effect in Cox(MgO)100-x granular thin films

    KAUST Repository

    Zhang, Qiang

    2017-07-31

    We investigated the mechanism(s) of the anomalous Hall effect (AHE) in magnetic granular materials by fabricating 100-nm-thick thin films of Cox(MgO)100-x with a Co volume fraction of 34≤x≤100 using co-sputtering at room temperature. We measured the temperature dependence of longitudinal resistivity (ρxx) and anomalous Hall resistivity (ρAHE) from 5 K to 300 K in all samples. We found that when x decreases from 100 to 34, the values of ρxx and ρAHE respectively increased by about four and three orders in magnitude. By linearly fitting the data, obtained at 5 K, of anomalous Hall coefficient (Rs) and of ρxx to log(Rs)~γlog(ρxx), we found that our results perfectly fell on a straight line with a slope of γ= 0.97±0.02. This fitting value of γ in Rsρxxγ clearly suggests that skew scattering dominated the AHE in this granular system. To explore the effect of the scattering on the AHE, we performed the same measurements on annealed samples. We found that although both ρxx and ρAHE significantly reduced after annealing, the correlation between them was almost the same, which was confirmed by the fitted value, γ=0.99±0.03. These data strongly suggest that the AHE originates from the skew scattering in Co-MgO granular thin films no matter how strong the scatterings of electrons by the interfaces and defects is. This observation may be of importance to the development of spintronic devices based on MgO.

  14. Information

    International Nuclear Information System (INIS)

    Boyard, Pierre.

    1981-01-01

    The fear for nuclear energy and more particularly for radioactive wastes is analyzed in the sociological context. Everybody agree on the information need, information is available but there is a problem for their diffusion. Reactions of the public are analyzed and journalists, scientists and teachers have a role to play [fr

  15. Viruses-to-mobile genetic elements skew in the deep Atlantis II brine pool sediments

    KAUST Repository

    Adel, Mustafa

    2016-09-06

    The central rift of the Red Sea has 25 brine pools with different physical and geochemical characteristics. Atlantis II (ATIID), Discovery Deeps (DD) and Chain Deep (CD) are characterized by high salinity, temperature and metal content. Several studies reported microbial communities in these brine pools, but few studies addressed the brine pool sediments. Therefore, sediment cores were collected from ATIID, DD, CD brine pools and an adjacent brine-influenced site. Sixteen different lithologic sediment sections were subjected to shotgun DNA pyrosequencing to generate 1.47 billion base pairs (1.47 × 109 bp). We generated sediment-specific reads and attempted to annotate all reads. We report the phylogenetic and biochemical uniqueness of the deepest ATIID sulfur-rich brine pool sediments. In contrary to all other sediment sections, bacteria dominate the deepest ATIID sulfur-rich brine pool sediments. This decrease in virus-to-bacteria ratio in selected sections and depth coincided with an overrepresentation of mobile genetic elements. Skewing in the composition of viruses-to-mobile genetic elements may uniquely contribute to the distinct microbial consortium in sediments in proximity to hydrothermally active vents of the Red Sea and possibly in their surroundings, through differential horizontal gene transfer.

  16. Non-linear analysis of skew thin plate by finite difference method

    International Nuclear Information System (INIS)

    Kim, Chi Kyung; Hwang, Myung Hwan

    2012-01-01

    This paper deals with a discrete analysis capability for predicting the geometrically nonlinear behavior of skew thin plate subjected to uniform pressure. The differential equations are discretized by means of the finite difference method which are used to determine the deflections and the in-plane stress functions of plates and reduced to several sets of linear algebraic simultaneous equations. For the geometrically non-linear, large deflection behavior of the plate, the non-linear plate theory is used for the analysis. An iterative scheme is employed to solve these quasi-linear algebraic equations. Several problems are solved which illustrate the potential of the method for predicting the finite deflection and stress. For increasing lateral pressures, the maximum principal tensile stress occurs at the center of the plate and migrates toward the corners as the load increases. It was deemed important to describe the locations of the maximum principal tensile stress as it occurs. The load-deflection relations and the maximum bending and membrane stresses for each case are presented and discussed

  17. Robustness of S1 statistic with Hodges-Lehmann for skewed distributions

    Science.gov (United States)

    Ahad, Nor Aishah; Yahaya, Sharipah Soaad Syed; Yin, Lee Ping

    2016-10-01

    Analysis of variance (ANOVA) is a common use parametric method to test the differences in means for more than two groups when the populations are normally distributed. ANOVA is highly inefficient under the influence of non- normal and heteroscedastic settings. When the assumptions are violated, researchers are looking for alternative such as Kruskal-Wallis under nonparametric or robust method. This study focused on flexible method, S1 statistic for comparing groups using median as the location estimator. S1 statistic was modified by substituting the median with Hodges-Lehmann and the default scale estimator with the variance of Hodges-Lehmann and MADn to produce two different test statistics for comparing groups. Bootstrap method was used for testing the hypotheses since the sampling distributions of these modified S1 statistics are unknown. The performance of the proposed statistic in terms of Type I error was measured and compared against the original S1 statistic, ANOVA and Kruskal-Wallis. The propose procedures show improvement compared to the original statistic especially under extremely skewed distribution.

  18. A Timing Estimation Method Based-on Skewness Analysis in Vehicular Wireless Networks.

    Science.gov (United States)

    Cui, Xuerong; Li, Juan; Wu, Chunlei; Liu, Jian-Hang

    2015-11-13

    Vehicle positioning technology has drawn more and more attention in vehicular wireless networks to reduce transportation time and traffic accidents. Nowadays, global navigation satellite systems (GNSS) are widely used in land vehicle positioning, but most of them are lack precision and reliability in situations where their signals are blocked. Positioning systems base-on short range wireless communication are another effective way that can be used in vehicle positioning or vehicle ranging. IEEE 802.11p is a new real-time short range wireless communication standard for vehicles, so a new method is proposed to estimate the time delay or ranges between vehicles based on the IEEE 802.11p standard which includes three main steps: cross-correlation between the received signal and the short preamble, summing up the correlated results in groups, and finding the maximum peak using a dynamic threshold based on the skewness analysis. With the range between each vehicle or road-side infrastructure, the position of neighboring vehicles can be estimated correctly. Simulation results were presented in the International Telecommunications Union (ITU) vehicular multipath channel, which show that the proposed method provides better precision than some well-known timing estimation techniques, especially in low signal to noise ratio (SNR) environments.

  19. A Timing Estimation Method Based-on Skewness Analysis in Vehicular Wireless Networks

    Directory of Open Access Journals (Sweden)

    Xuerong Cui

    2015-11-01

    Full Text Available Vehicle positioning technology has drawn more and more attention in vehicular wireless networks to reduce transportation time and traffic accidents. Nowadays, global navigation satellite systems (GNSS are widely used in land vehicle positioning, but most of them are lack precision and reliability in situations where their signals are blocked. Positioning systems base-on short range wireless communication are another effective way that can be used in vehicle positioning or vehicle ranging. IEEE 802.11p is a new real-time short range wireless communication standard for vehicles, so a new method is proposed to estimate the time delay or ranges between vehicles based on the IEEE 802.11p standard which includes three main steps: cross-correlation between the received signal and the short preamble, summing up the correlated results in groups, and finding the maximum peak using a dynamic threshold based on the skewness analysis. With the range between each vehicle or road-side infrastructure, the position of neighboring vehicles can be estimated correctly. Simulation results were presented in the International Telecommunications Union (ITU vehicular multipath channel, which show that the proposed method provides better precision than some well-known timing estimation techniques, especially in low signal to noise ratio (SNR environments.

  20. The male handicap: male-biased mortality explains skewed sex ratios in brown trout embryos.

    Science.gov (United States)

    Morán, P; Labbé, L; Garcia de Leaniz, C

    2016-12-01

    Juvenile sex ratios are often assumed to be equal for many species with genetic sex determination, but this has rarely been tested in fish embryos due to their small size and absence of sex-specific markers. We artificially crossed three populations of brown trout and used a recently developed genetic marker for sexing the offspring of both pure and hybrid crosses. Sex ratios (SR = proportion of males) varied widely one month after hatching ranging from 0.15 to 0.90 (mean = 0.39 ± 0.03). Families with high survival tended to produce balanced or male-biased sex ratios, but SR was significantly female-biased when survival was low, suggesting that males sustain higher mortality during development. No difference in SR was found between pure and hybrid families, but the existence of sire × dam interactions suggests that genetic incompatibility may play a role in determining sex ratios. Our findings have implications for animal breeding and conservation because skewed sex ratios will tend to reduce effective population size and bias selection estimates. © 2016 The Authors.

  1. Strong reproductive skew among males in the multiply mated swordtail Xiphophorus multilineatus (Teleostei).

    Science.gov (United States)

    Luo, J; Sanetra, M; Schartl, M; Meyer, A

    2005-01-01

    Male swordtails in the genus Xiphophorus display a conspicuous ventral elongation of the caudal fin, the sword, which arose through sexual selection due to female preference. Females mate regularly and are able to store sperm for at least 6 months. If multiple mating is frequent, this would raise the intriguing question about the role of female choice and male-male competition in shaping the mating system of these fishes. Size-dependent alternate mating strategies occur in Xiphophorus; one such strategy is courtship with a sigmoid display by large dominant males, while the other is gonopodial thrusting, in which small subordinate males sneak copulations. Using microsatellite markers, we observed a frequency of multiple paternity in wild-caught Xiphophorus multilineatus in 28% of families analyzed, but the actual frequency of multiple mating suggested by the correction factor PrDM was 33%. The number of fathers contributing genetically to the brood ranged from one to three. Compared to other species in the family Poeciliidae, both frequency and degree of multiple paternity were low. Paternity was found to be highly skewed, with one male on average contributing more than 70% to the offspring. Hence in this Xiphophorus mating system, typically one male dominates and sneaker males do not appear to be particularly effective. Postcopulatory mechanisms, however, such as sperm competition, are also indicated by our data, using sex-linked phenotypes among the offspring.

  2. Lactobacilli activate human dendritic cells that skew T cells toward T helper 1 polarization.

    Science.gov (United States)

    Mohamadzadeh, Mansour; Olson, Scott; Kalina, Warren V; Ruthel, Gordon; Demmin, Gretchen L; Warfield, Kelly L; Bavari, Sina; Klaenhammer, Todd R

    2005-02-22

    Professional antigen-presenting dendritic cells (DCs) are critical in regulating T cell immune responses at both systemic and mucosal sites. Many Lactobacillus species are normal members of the human gut microflora and most are regarded as safe when administered as probiotics. Because DCs can naturally or therapeutically encounter lactobacilli, we investigated the effects of several well defined strains, representing three species of Lactobacillus on human myeloid DCs (MDCs) and found that they modulated the phenotype and functions of human MDCs. Lactobacillus-exposed MDCs up-regulated HLA-DR, CD83, CD40, CD80, and CD86 and secreted high levels of IL-12 and IL-18, but not IL-10. IL-12 was sustained in MDCs exposed to all three Lactobacillus species in the presence of LPS from Escherichia coli, whereas LPS-induced IL-10 was greatly inhibited. MDCs activated with lactobacilli clearly skewed CD4(+) and CD8(+) T cells to T helper 1 and Tc1 polarization, as evidenced by secretion of IFN-gamma, but not IL-4 or IL-13. These results emphasize a potentially important role for lactobacilli in modulating immunological functions of DCs and suggest that certain strains could be particularly advantageous as vaccine adjuvants, by promoting DCs to regulate T cell responses toward T helper 1 and Tc1 pathways.

  3. A unique dermal dendritic cell subset that skews the immune response toward Th2.

    Directory of Open Access Journals (Sweden)

    Ryuichi Murakami

    Full Text Available Dendritic cell (DC subsets in the skin and draining lymph nodes (LNs are likely to elicit distinct immune response types. In skin and skin-draining LNs, a dermal DC subset expressing macrophage galactose-type C-type lectin 2 (MGL2/CD301b was found distinct from migratory Langerhans cells (LCs or CD103(+ dermal DCs (dDCs. Lower expression levels of Th1-promoting and/or cross-presentation-related molecules were suggested by the transcriptome analysis and verified by the quantitative real-time PCR analysis in MGL2(+ dDCs than in CD103(+ dDCs. Transfer of MGL2(+ dDCs but not CD103(+ dDCs from FITC-sensitized mice induced a Th2-type immune response in vivo in a model of contact hypersensitivity. Targeting MGL2(+ dDCs with a rat monoclonal antibody against MGL2 efficiently induced a humoral immune response with Th2-type properties, as determined by the antibody subclass. We propose that the properties of MGL2(+ dDCs, are complementary to those of CD103(+ dDCs and skew the immune response toward a Th2-type response.

  4. Skewed riskscapes and gentrified inequities: environmental exposure disparities in Seattle, Washington.

    Science.gov (United States)

    Abel, Troy D; White, Jonah

    2011-12-01

    Few studies have considered the sociohistorical intersection of environmental injustice and gentrification; a gap addressed by this case study of Seattle, Washington. This study explored the advantages of integrating air toxic risk screening with gentrification research to enhance proximity and health equity analysis methodologies. It was hypothesized that Seattle's industrial air toxic exposure risk was unevenly dispersed, that gentrification stratified the city's neighborhoods, and that the inequities of both converged. Spatial characterizations of air toxic pollution risk exposures from 1990 to 2007 were combined with longitudinal cluster analysis of census block groups in Seattle, Washington, from 1990 to 2000. A cluster of air toxic exposure inequality and socioeconomic inequity converged in 1 area of south central Seattle. Minority and working class residents were more concentrated in the same neighborhoods near Seattle's worst industrial pollution risks. Not all pollution was distributed equally in a dynamic urban landscape. Using techniques to examine skewed riskscapes and socioeconomic urban geographies provided a foundation for future research on the connections among environmental health hazard sources, socially vulnerable neighborhoods, and health inequity.

  5. Adjustment model of thermoluminescence experimental data

    International Nuclear Information System (INIS)

    Moreno y Moreno, A.; Moreno B, A.

    2002-01-01

    This model adjusts the experimental results for thermoluminescence according to the equation: I (T) = I (a i * exp (-1/b i * (T-C i )) where: a i , b i , c i are the i-Th peak adjusted to a gaussian curve. The adjustments of the curve can be operated manual or analytically using the macro function and the solver.xla complement installed previously in the computational system. In this work it is shown: 1. The information of experimental data from a LiF curve obtained from the Physics Institute of UNAM which the data adjustment model is operated in the macro type. 2. A LiF curve of four peaks obtained from Harshaw information simulated in Microsoft Excel, discussed in previous works, as a reference not in macro. (Author)

  6. High-speed broadband elastic actuator in water using induced-charge electro-osmosis with a skew structure

    Science.gov (United States)

    Sugioka, Hideyuki; Nakano, Naoki

    2018-01-01

    An artificial cilium using ac electro-osmosis (ACEO) is attractive because of its large potentiality for innovative microfluidic applications. However, the ACEO cilium has not been probed experimentally and has a shortcoming that the working frequency range is very narrow. Thus, we here propose an ACEO elastic actuator having a skew structure that broadens a working frequency range and experimentally demonstrate that the elastic actuator in water can be driven with a high-speed (˜10 Hz) and a wide frequency range (˜0.1 to ˜10 kHz). Moreover, we propose a simple self-consistent model that explains the broadband characteristic due to the skew structure with other characteristics. By comparing the theoretical results with the experimental results, we find that they agree fairly well. We believe that our ACEO elastic actuator will play an important role in microfluidics in the future.

  7. Non-skew-symmetric classical r-matrices, algebraic Bethe ansatz, and Bardeen-Cooper-Schrieffer-type integrable systems

    International Nuclear Information System (INIS)

    Skrypnyk, T.

    2009-01-01

    We construct quantum integrable systems associated with non-skew-symmetric gl(2)-valued classical r-matrices. We find a new explicit multiparametric family of such the non-skew-symmetric classical r-matrices. We consider two classes of examples of the corresponding integrable systems, namely generalized Gaudin systems with and without an external magnetic field. In the case of arbitrary r-matrices diagonal in a standard gl(2)-basis, we calculate the spectrum of the corresponding quantum integrable systems using the algebraic Bethe ansatz. We apply these results to a construction of integrable fermionic models and obtain a wide class of integrable Bardeen-Cooper-Schrieffer (BCS)-type fermionic Hamiltonians containing the pairing and electrostatic interaction terms. We also consider special cases when the corresponding integrable Hamiltonians contain only pairing interaction term and are exact analogs of the 'reduced BCS Hamiltonian' of Richardson

  8. Development and Validation of a New Blade Element Momentum Skewed-Wake Model within AeroDyn: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ning, S. A.; Hayman, G.; Damiani, R.; Jonkman, J.

    2014-12-01

    Blade element momentum methods, though conceptually simple, are highly useful for analyzing wind turbines aerodynamics and are widely used in many design and analysis applications. A new version of AeroDyn is being developed to take advantage of new robust solution methodologies, conform to a new modularization framework for National Renewable Energy Laboratory's FAST, utilize advanced skewed-wake analysis methods, fix limitations with previous implementations, and to enable modeling of highly flexible and nonstraight blades. This paper reviews blade element momentum theory and several of the options available for analyzing skewed inflow. AeroDyn implementation details are described for the benefit of users and developers. These new options are compared to solutions from the previous version of AeroDyn and to experimental data. Finally, recommendations are given on how one might select from the various available solution approaches.

  9. High-speed broadband elastic actuator in water using induced-charge electro-osmosis with a skew structure.

    Science.gov (United States)

    Sugioka, Hideyuki; Nakano, Naoki

    2018-01-01

    An artificial cilium using ac electro-osmosis (ACEO) is attractive because of its large potentiality for innovative microfluidic applications. However, the ACEO cilium has not been probed experimentally and has a shortcoming that the working frequency range is very narrow. Thus, we here propose an ACEO elastic actuator having a skew structure that broadens a working frequency range and experimentally demonstrate that the elastic actuator in water can be driven with a high-speed (∼10 Hz) and a wide frequency range (∼0.1 to ∼10 kHz). Moreover, we propose a simple self-consistent model that explains the broadband characteristic due to the skew structure with other characteristics. By comparing the theoretical results with the experimental results, we find that they agree fairly well. We believe that our ACEO elastic actuator will play an important role in microfluidics in the future.

  10. Informe

    Directory of Open Access Journals (Sweden)

    Egon Lichetenberger

    1950-10-01

    Full Text Available Informe del doctor Egon Lichetenberger ante el Consejo Directivo de la Facultad, sobre el  curso de especialización en Anatomía Patológica patrocinado por la Kellogg Foundation (Departamento de Patología

  11. Mapping Causes and Implications of India's Skewed Sex Ratio and Poverty problem using Fuzzy & Neutrosophic Relational Maps

    OpenAIRE

    Gaurav; Kumar, Megha; Bhutani, Kanika; Aggarwal, Swati

    2016-01-01

    Numerous studies by different researchers have confirmed that skewed sex ratio is a critical social problem in India. This enduring problem of gender imbalance is the collective result of factors like sex selective abortion, gender discrimination, son preference for the preservation of tribe, emergence of new technologies in medical field and many more factors. Another severe problem to be addressed in India is poverty. Many factors contribute to the perpetuation of poverty such as illiteracy...

  12. Text Categorization Using Weight Adjusted k-Nearest Neighbor Classification

    National Research Council Canada - National Science Library

    Han, Euihong; Karypis, George; Kumar, Vipin

    1999-01-01

    .... The authors present a nearest neighbor classification scheme for text categorization in which the importance of discriminating words is learned using mutual information and weight adjustment techniques...

  13. Downhole adjustable bent assemblies

    International Nuclear Information System (INIS)

    Askew, W.E.

    1992-01-01

    This patent describes downhole adjustable apparatus for creating a bend angle in order to affect the inclination of a drilled borehole. It comprises an upper tubular member having an upper portion and a lower portion; lower tubular member having an upper portion and a lower portion; one of the portions being received within the other for relative rotational movement about an axis that is inclined with respect to the the longitudinal axes of the members, whereby in a first rotational position the longitudinal axes have one geometrical relationship, and in a second rotational position the longitudinal axes have a second, different geometrical relationship

  14. The structure of mode-locking regions of piecewise-linear continuous maps: II. Skew sawtooth maps

    Science.gov (United States)

    Simpson, D. J. W.

    2018-05-01

    In two-parameter bifurcation diagrams of piecewise-linear continuous maps on , mode-locking regions typically have points of zero width known as shrinking points. Near any shrinking point, but outside the associated mode-locking region, a significant proportion of parameter space can be usefully partitioned into a two-dimensional array of annular sectors. The purpose of this paper is to show that in these sectors the dynamics is well-approximated by a three-parameter family of skew sawtooth circle maps, where the relationship between the skew sawtooth maps and the N-dimensional map is fixed within each sector. The skew sawtooth maps are continuous, degree-one, and piecewise-linear, with two different slopes. They approximate the stable dynamics of the N-dimensional map with an error that goes to zero with the distance from the shrinking point. The results explain the complicated radial pattern of periodic, quasi-periodic, and chaotic dynamics that occurs near shrinking points.

  15. Aerodynamic forces and galloping instability for a skewed elliptical cylinder in a flow at the critical Reynolds number

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Wenyong [Wind Engineering Research Center, Shijiazhuang Tiedao University, Shijiazhuang, Hebei 050043 (China); Liu, Qingkuan; Liu, Xiaobing [The Key Laboratory for Health Monitoring and Control of Large Structures, Hebei province, 050043 (China); Du, Xiaoqing, E-mail: ma@stdu.edu.cn, E-mail: dxq@shu.edu.cn [Department of Civil Engineering, Shanghai University, Shanghai, 200072 (China)

    2017-08-15

    The mechanism of large-amplitude aeroelastic vibrations of cylindrical bodies in the critical Reynolds number range are still unclear. This study concerns the aerodynamic forces acting on elliptical cylinders and the induced galloping instability resulting from skew flows (i.e., the direction of the flow is angled 0°–45° with respect to the central axis of the cylinder) for Reynolds numbers in the range of 37–235 k. The effects of the critical Reynolds number and the skew angle on the aerodynamic forces and the galloping instability are investigated with pressure wind tunnel tests. In all of the cases investigated in the present study, a sharp decrease in the lift coefficient with increasing angle of attack and a reduction in the drag coefficient at the critical Reynolds number could be responsible for the galloping instability. Variations in the torque coefficient leads to a torsional aerodynamic instability at the critical Reynolds number. Furthermore, the skew flow cause a critical flow state at lower Reynolds numbers. One possible reason for this behavior is that the longer effective cross section allows the flow to reattach. (paper)

  16. Skewed task conflicts in teams: What happens when a few members see more conflict than the rest?

    Science.gov (United States)

    Sinha, Ruchi; Janardhanan, Niranjan S; Greer, Lindred L; Conlon, Donald E; Edwards, Jeffery R

    2016-07-01

    Task conflict has been the subject of a long-standing debate in the literature-when does task conflict help or hurt team performance? We propose that this debate can be resolved by taking a more precise view of how task conflicts are perceived in teams. Specifically, we propose that in teams, when a few team members perceive a high level of task disagreement while a majority of others perceive low levels of task disagreement-that is, there is positively skewed task conflict, task conflict is most likely to live up to its purported benefits for team performance. In our first study of student teams engaged in a business decision game, we find support for the positive relationship between skewed task conflict and team performance. In our second field study of teams in a financial corporation, we find that the relationship between positively skewed task conflict and supervisor ratings of team performance is mediated by reflective communication within the team. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  17. Skewness and flatness factors of the longitudinal velocity derivative in wall-bounded flows

    Science.gov (United States)

    Djenidi, Lyazid; Antonia, Robert A.; Talluru, Murali K.; Abe, Hiroyuki

    2017-06-01

    Hot-wire measurements are carried out in turbulent boundary layers over smooth and rough walls in order the assess the behavior of the skewness (S ) and flatness (F ) factors of the longitudinal velocity derivative as y , the distance from the wall, increases. The measurements are complemented by direct numerical simulations of a smooth wall turbulent channel flow. It is observed that, as the distance to the wall increases, S and F vary significantly before approaching a constant in the outer layer of the boundary layer. Further, S and F exhibit a nontrivial dependence on the Taylor microscale Reynolds number (Reλ). For example, in the region below about 0.2 δ (δ is the boundary layer thickness) where Reλ varies significantly, S and F strongly vary with Reλ and can be multivalued at a given Reλ. In the outer region, between 0.3 δ and 0.6 δ , S , F , and Reλ remain approximately constant. The channel flow direct numerical simulation data for S and F exhibit a similar behavior. These results point to the ambiguity that can arise when assessing the Reλ dependence of S and F in wall shear flows. In particular, the multivaluedness of S and F can lead to erroneous conclusions if y /δ is known only poorly, as is the case for the atmospheric shear layer (ASL). If the laboratory turbulent boundary layer is considered an adequate surrogate to the neutral ASL, then the behavior of S and F in the ASL is expected to be similar to that reported here.

  18. Cadmium modulates hematopoietic stem and progenitor cells and skews toward myelopoiesis in mice

    International Nuclear Information System (INIS)

    Zhang, Yandong; Yu, Xinchun; Sun, Shuhui; Li, Qian; Xie, Yunli; Li, Qiang; Zhao, Yifan; Pei, Jianfeng; Zhang, Wenmin; Xue, Peng; Zhou, Zhijun; Zhang, Yubin

    2016-01-01

    The heavy metal cadmium (Cd) is known to modulate immunity and cause osteoporosis. However, how Cd influences on hematopoiesis remain largely unknown. Herein, we show that wild-type C57BL/6 (B6) mice exposed to Cd for 3 months had expanded bone marrow (BM) populations of long-term hematopoietic stem cells (LT-HSCs), common myeloid progenitors (CMPs) and granulocyte-macrophage progenitors (GMPs), while having reduced populations of multipotent progenitors (MPPs) and common lymphoid progenitors (CLPs). A competitive mixed BM transplantation assay indicates that BM from Cd-treated mice had impaired LT-HSC ability to differentiate into mature cells. In accordance with increased myeloid progenitors and decreased lymphoid progenitors, the BM and spleens of Cd-treated mice had more monocytes and/or neutrophils and fewer B cells and T cells. Cd impaired the ability of the non-hematopoietic system to support LT-HSCs, in that lethally irradiated Cd-treated recipients transplanted with normal BM cells had reduced LT-HSCs after the hematopoietic system was fully reconstituted. This is consistent with reduced osteoblasts, a known critical component for HSC niche, observed in Cd-treated mice. Conversely, lethally irradiated control recipients transplanted with BM cells from Cd-treated mice had normal LT-HSC reconstitution. Furthermore, both control mice and Cd-treated mice that received Alendronate, a clinical drug used for treating osteoporosis, had BM increases of LT-HSCs. Thus, the results suggest Cd increase of LT-HSCs is due to effects on HSCs and not on osteoblasts, although, Cd causes osteoblast reduction and impaired niche function for maintaining HSCs. Furthermore, Cd skews HSCs toward myelopoiesis. - Highlights: • Cd increases the number of LT-HSCs but impairs their development. • Cd-treated hosts have compromised ability to support LT-HSCs. • Cd promotes myelopoiesis at the expense of lymphopoiesis at the MPP level.

  19. Cadmium modulates hematopoietic stem and progenitor cells and skews toward myelopoiesis in mice

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yandong; Yu, Xinchun [School of Public Health and Key Laboratory of Public Health, MOE, Fudan University, Shanghai 200032 (China); Sun, Shuhui [Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Li, Qian [School of Public Health and Key Laboratory of Public Health, MOE, Fudan University, Shanghai 200032 (China); Xie, Yunli [Insititute of Brain Sciences, Fudan University, Shanghai 200032 (China); Li, Qiang [Putuo District Center for Disease Control and Prevention, Shanghai 200062 (China); Zhao, Yifan; Pei, Jianfeng; Zhang, Wenmin; Xue, Peng; Zhou, Zhijun [School of Public Health and Key Laboratory of Public Health, MOE, Fudan University, Shanghai 200032 (China); Zhang, Yubin, E-mail: yz001@fudan.edu.cn [School of Public Health and Key Laboratory of Public Health, MOE, Fudan University, Shanghai 200032 (China)

    2016-12-15

    The heavy metal cadmium (Cd) is known to modulate immunity and cause osteoporosis. However, how Cd influences on hematopoiesis remain largely unknown. Herein, we show that wild-type C57BL/6 (B6) mice exposed to Cd for 3 months had expanded bone marrow (BM) populations of long-term hematopoietic stem cells (LT-HSCs), common myeloid progenitors (CMPs) and granulocyte-macrophage progenitors (GMPs), while having reduced populations of multipotent progenitors (MPPs) and common lymphoid progenitors (CLPs). A competitive mixed BM transplantation assay indicates that BM from Cd-treated mice had impaired LT-HSC ability to differentiate into mature cells. In accordance with increased myeloid progenitors and decreased lymphoid progenitors, the BM and spleens of Cd-treated mice had more monocytes and/or neutrophils and fewer B cells and T cells. Cd impaired the ability of the non-hematopoietic system to support LT-HSCs, in that lethally irradiated Cd-treated recipients transplanted with normal BM cells had reduced LT-HSCs after the hematopoietic system was fully reconstituted. This is consistent with reduced osteoblasts, a known critical component for HSC niche, observed in Cd-treated mice. Conversely, lethally irradiated control recipients transplanted with BM cells from Cd-treated mice had normal LT-HSC reconstitution. Furthermore, both control mice and Cd-treated mice that received Alendronate, a clinical drug used for treating osteoporosis, had BM increases of LT-HSCs. Thus, the results suggest Cd increase of LT-HSCs is due to effects on HSCs and not on osteoblasts, although, Cd causes osteoblast reduction and impaired niche function for maintaining HSCs. Furthermore, Cd skews HSCs toward myelopoiesis. - Highlights: • Cd increases the number of LT-HSCs but impairs their development. • Cd-treated hosts have compromised ability to support LT-HSCs. • Cd promotes myelopoiesis at the expense of lymphopoiesis at the MPP level.

  20. Adjustment disorder: current perspectives

    Directory of Open Access Journals (Sweden)

    Zelviene P

    2018-01-01

    Full Text Available Paulina Zelviene, Evaldas Kazlauskas Department of Clinical and Organizational Psychology, Vilnius University, Vilnius, Lithuania Abstract: Adjustment disorder (AjD is among the most often diagnosed mental disorders in clinical practice. This paper reviews current status of AjD research and discusses scientific and clinical issues associated with AjD. AjD has been included in diagnostic classifications for over 50 years. Still, the diagnostic criteria for AjD remain vague and cause difficulties to mental health professionals. Controversies in definition resulted in the lack of reliable and valid measures of AjD. Epidemiological data on prevalence of AjD is scarce and not reliable because prevalence data are biased by the diagnostic algorithm, which is usually developed for each study, as no established diagnostic standards for AjD are available. Considerable changes in the field of AjD could follow after the release of the 11th edition of International Classification of Diseases (ICD-11. A new AjD symptom profile was introduced in ICD-11 with 2 main symptoms as follows: 1 preoccupation and 2 failure to adapt. However, differences between the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition and ICD-11 AjD diagnostic criteria could result in diverse research findings in the future. The best treatment approach for AjD remains unclear, and further treatment studies are needed to provide AjD treatment guidelines to clinicians. Keywords: adjustment disorder, review, diagnosis, prevalence, treatment, DSM, ICD

  1. Continuously adjustable Pulfrich spectacles

    Science.gov (United States)

    Jacobs, Ken; Karpf, Ron

    2011-03-01

    A number of Pulfrich 3-D movies and TV shows have been produced, but the standard implementation has inherent drawbacks. The movie and TV industries have correctly concluded that the standard Pulfrich 3-D implementation is not a useful 3-D technique. Continuously Adjustable Pulfrich Spectacles (CAPS) is a new implementation of the Pulfrich effect that allows any scene containing movement in a standard 2-D movie, which are most scenes, to be optionally viewed in 3-D using inexpensive viewing specs. Recent scientific results in the fields of human perception, optoelectronics, video compression and video format conversion are translated into a new implementation of Pulfrich 3- D. CAPS uses these results to continuously adjust to the movie so that the viewing spectacles always conform to the optical density that optimizes the Pulfrich stereoscopic illusion. CAPS instantly provides 3-D immersion to any moving scene in any 2-D movie. Without the glasses, the movie will appear as a normal 2-D image. CAPS work on any viewing device, and with any distribution medium. CAPS is appropriate for viewing Internet streamed movies in 3-D.

  2. Adjustment Criterion and Algorithm in Adjustment Model with Uncertain

    Directory of Open Access Journals (Sweden)

    SONG Yingchun

    2015-02-01

    Full Text Available Uncertainty often exists in the process of obtaining measurement data, which affects the reliability of parameter estimation. This paper establishes a new adjustment model in which uncertainty is incorporated into the function model as a parameter. A new adjustment criterion and its iterative algorithm are given based on uncertainty propagation law in the residual error, in which the maximum possible uncertainty is minimized. This paper also analyzes, with examples, the different adjustment criteria and features of optimal solutions about the least-squares adjustment, the uncertainty adjustment and total least-squares adjustment. Existing error theory is extended with new observational data processing method about uncertainty.

  3. Chemical Thermodynamics and Information Theory with Applications

    CERN Document Server

    Graham, Daniel J

    2011-01-01

    Thermodynamics and information touch theory every facet of chemistry. However, the physical chemistry curriculum digested by students worldwide is still heavily skewed toward heat/work principles established more than a century ago. Rectifying this situation, Chemical Thermodynamics and Information Theory with Applications explores applications drawn from the intersection of thermodynamics and information theory--two mature and far-reaching fields. In an approach that intertwines information science and chemistry, this book covers: The informational aspects of thermodynamic state equations The

  4. Halo Pressure Profile through the Skew Cross-power Spectrum of the Sunyaev–Zel’dovich Effect and CMB Lensing in Planck

    Energy Technology Data Exchange (ETDEWEB)

    Timmons, Nicholas; Cooray, Asantha; Feng, Chang [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Keating, Brian [Department of Physics, University of California, San Diego, La Jolla, CA 92093 (United States)

    2017-11-01

    We measure the cosmic microwave background (CMB) skewness power spectrum in Planck , using frequency maps of the HFI instrument and the Sunyaev–Zel’dovich (SZ) component map. The two-to-one skewness power spectrum measures the cross-correlation between CMB lensing and the thermal SZ effect. We also directly measure the same cross-correlation using the Planck CMB lensing map and the SZ map and compare it to the cross-correlation derived from the skewness power spectrum. We model fit the SZ power spectrum and CMB lensing–SZ cross-power spectrum via the skewness power spectrum to constrain the gas pressure profile of dark matter halos. The gas pressure profile is compared to existing measurements in the literature including a direct estimate based on the stacking of SZ clusters in Planck .

  5. Adjustable continence balloons

    DEFF Research Database (Denmark)

    Kjær, Line; Fode, Mikkel; Nørgaard, Nis

    2012-01-01

    Abstract Objective. This study aimed to evaluate the results of the Danish experience with the ProACT urinary continence device inserted in men with stress urinary incontinence. Material and methods. The ProACT was inserted in 114 patients. Data were registered prospectively. The main endpoints...... in urinary leakage > 50% was seen in 72 patients (80%). Complications were seen in 23 patients. All of these were treated successfully by removal of the device in the outpatient setting followed by replacement of the device. Another eight patients had a third balloon inserted to improve continence further....... Fourteen patients (12%) ended up with an artificial sphincter or a urethral sling. Sixty patients (63%) experienced no discomfort and 58 (61%) reported being dry or markedly improved. Overall, 50 patients (53%) reported being very or predominantly satisfied. Conclusions. Adjustable continence balloons seem...

  6. Premalignant lesions skew spleen cell responses to immune modulation by adipocytes.

    Science.gov (United States)

    Vielma, Silvana A; Klein, Richard L; Levingston, Corinne A; Young, M Rita I

    2013-05-01

    Obesity can promote a chronic inflammatory state and is associated with an increased risk for cancer. Since adipocytes can produce mediators that can regulate conventional immune cells, this study sought to determine if the presence of premalignant oral lesions would skew how immune cells respond to adipocyte-derived mediators to create an environment that may be more favorable for their progression toward cancer. While media conditioned by adipocytes stimulated normal spleen cell production of the T helper (Th) type-1 cytokines interleukin (IL)-2, interferon-γ (IFN-γ), IL-12 and granulocyte-monocyte colony-stimulating factor (GM CSF), media from premalignant lesion cells either blocked or had no added affect on the adipocyte-stimulated Th1 cytokine production. In contrast, media conditioned by premalignant lesion cells exacerbated adipocyte-stimulated spleen cell production of the Th2 cytokines IL-10 and IL-13, although it did not further enhance the adipocyte-stimulated spleen cell production of IL-4 and TGF-β. The premalignant lesion environment also heightened the adipocyte-stimulated spleen cell production of the inflammatory mediators IL 1α, IL-1β, IL-6 and IL-9, although it did not further increase the adipocyte-stimulated production of tumor necrosis factor-α (TNF-α). IL 17 production was unaffected by the adipocyte-derived mediators, but was synergistically triggered by adding media from premalignant lesion cells. These stimulatory effects on spleen cell production of Th2 and inflammatory mediators were not induced in the absence of media conditioned by adipocytes. In contrast, media conditioned by adipocytes did not stimulate production of predominantly monocyte-derived chemokine C-X-C motif ligand (CXCL)9, chemokine C-C motif ligand (CCL)3 or CCL4, although it stimulated production of CCL2 and the predominantly T cell-derived chemokine CCL5, which was the only chemokine whose production was further increased by media from premalignant lesions

  7. Influence of skew rays on the sensitivity and signal-to-noise ratio of a fiber-optic surface-plasmon-resonance sensor: a theoretical study

    International Nuclear Information System (INIS)

    Dwivedi, Yogendra S.; Sharma, Anuj K.; Gupta, Banshi D.

    2007-01-01

    We have theoretically analyzed the influence of skew rays on the performance of a fiber-optic sensor based on surface plasmon resonance. The performance of the sensor has been evaluated in terms of its sensitivity and signal-to-noise ratio (SNR). The theoretical model for skewness dependence includes the material dispersion in fiber cores and metal layers, simultaneous excitation of skew rays, and meridional rays in the fiber core along with all guided rays launching from a collimated light source. The effect of skew rays on the SNR and the sensitivity of the sensor with two different metals has been compared. The same comparison is carried out for the different values of design parameters such as numerical aperture, fiber core diameter, and the length of the surface-plasmon-resonance (SPR)active sensing region. This detailed analysis for the effect of skewness on the SNR and the sensitivity of the sensor leads us to achieve the best possible performance from a fiber-optic SPR sensor against the skewness in the optical fiber

  8. Adolescent Mothers' Adjustment to Parenting.

    Science.gov (United States)

    Samuels, Valerie Jarvis; And Others

    1994-01-01

    Examined adolescent mothers' adjustment to parenting, self-esteem, social support, and perceptions of baby. Subjects (n=52) responded to questionnaires at two time periods approximately six months apart. Mothers with higher self-esteem at Time 1 had better adjustment at Time 2. Adjustment was predicted by Time 2 variables; contact with baby's…

  9. HPGe detector shielding adjustment

    International Nuclear Information System (INIS)

    Trnkova, L.; Rulik, P.

    2008-01-01

    Low-level background shielding of HPGe detectors is used mainly for environmental samples with very low content of radionuclides. National Radiation Protection Institute (SURO) in Prague is equipped with 14 HPGe detectors with relative efficiency up to 150%. The detectors are placed in a room built from materials with low content of natural radionuclides and equipped with a double isolation of the floor against radon. Detectors themselves are placed in lead or steel shielding. Steel shielding with one of these detectors with relative efficiency of 100% was chosen to be rebuilt to achieve lower minimum detectable activity (MDA). Additional lead and copper shielding was built up inside the original steel shielding to reduce the volume of the inner space and filled with nitrogen by means of evaporating liquid nitrogen. The additional lead and copper shielding, consequent reduction of the inner volume and supply of evaporated nitrogen, caused a decrease of the background count and accordingly MDA values as well. The effect of nitrogen evaporation on the net areas of peaks belonging to radon daughters is significant. The enhanced shielding adjustment has the biggest influence in low energy range, what can be seen in collected data. MDA values in energy range from 30 keV to 400 keV decreased to 0.65-0.85 of original value, in energy range from 400 keV to 2 MeV they fell to 0.70-0.97 of original value. (authors)

  10. Underwriters' view of risk - An adjuster's perspective

    International Nuclear Information System (INIS)

    Smith, M.

    1992-01-01

    This paper reviews how a risk assessment is performed by an insurance adjuster to determine rates and insurability of a client. It provides a historical perspective on insurance and how information systems are used to monitor past claims to determine future risk. Although this paper does not specifically address the oil and gas industry, it is informative in identifying how insurance rates are determined and risk assessments for various oil and gas operations are performed

  11. True Polar Wander and Hotspot Fixity: A Paleomagnetic Investigation of the Skewness of Magnetic Anomaly 12r (32 Ma B.P.) on the Pacific Plate

    Science.gov (United States)

    Gordon, R. G.; Horner-Johnson, B. C.

    2010-12-01

    Prior studies have shown that Pacific hotspots and Indo-Atlantic hotspots have moved in approximate unison relative to the spin axis since 65 Ma B.P. [Morgan, 1981; Gordon and Cape, 1981; Gordon, 1982] and since 56 Ma B.P. [Petronotis et al., 1994], which is most simply interpreted as true polar wander. In contrast, Pacific hotspots and Indo-Atlantic hotspots give conflicting results for 72 Ma B.P. and for 81 Ma B.P., which may indicate motion between Pacific hotspots and Indo-Atlantic hotspots [Tarduno and Cottrell, 1997; Petronotis et al., 1999; Tarduno et al., 2003]. Thus it is important to estimate Pacific plate apparent polar wander (APW) for more time intervals. From such estimates the APW of Pacific hotspots can be inferred and compared with that of Indo-Atlantic hotspots [e.g., Besse and Courtillot 2002]. Here we present a study of the skewness of anomaly 12r between the Galapagos and Clipperton and between the Clipperton and Clarion fracture zones. We chose this region for several reasons: First, numerical experiments, like those conducted by Acton and Gordon [1991], indicate that magnetic profiles between the Galapagos and Clarion fracture zones should contain the most information about the Pacific plate paleomagnetic pole for chron C12r (32 Ma B.P.). Second, in these two spreading rate corridors, spreading half rates range from 72 to 86 mm/a and therefore have negligible anomalous skewness, given that they exceed ≈50 mm/a [Roest et al., 1992; Dyment et al. 1994]. Third, vector aeromagnetic profiles are available for analysis. One of the challenges to interpreting magnetic anomalies in low latitudes where the anomalies strike nearly north-south is the very low amplitude of the signal relative to the noise, the latter of which can be especially intense near the present magnetic equator due to the amplification of diurnal variation by the equatorial electrojet. Previously we showed that vector aeromagnetic profiles record low-latitude Pacific plate

  12. Stability management of high speed axial flow compressor stage through axial extensions of bend skewed casing treatment

    Directory of Open Access Journals (Sweden)

    DilipkumarBhanudasji Alone

    2016-09-01

    Full Text Available This paper presents the experimental results to understand the performance of moderately loaded high speed single stage transonic axial flow compressor subjected to various configurations of axial extensions of bend skewed casing treatment with moderate porosity. The bend skewed casing treatment of 33% porosity was coupled with rectangular plenum chamber of depth equal to the slots depth. The five axial extensions of 20%, 40%, 60%, 80% and 100% were used for the experimental evaluations of compressor performance. The main objective was to identify the optimum extension of the casing treatment with reference to rotor leading edge which results in maximum stall margin improvements with minimum loss in the stage efficiency. At each axial extension the compressor performance is distinctive. The improvement in the stall margin was very significant at some axial extensions with 4%–5% penalty in the stage efficiency. The compressors stage shows recovery in terms of efficiency at lower axial extensions of 20% and 40% with increase in the peak stage efficiency. Measurements of flow parameters showed the typical behaviors at near stall flow conditions. Hot wire sensor was placed at the rotor upstream in the tip region to capture the oscillations in the inlet axial and tangential velocities at stall conditions. In the absence of casing treatment the compressor exhibit abrupt stall with very high oscillations in the inlet axial and tangential velocity of the flow. The extents of oscillations reduce with bend skewed casing treatment. Few measurements were also performed in the plenum chamber and salient results are presented in this paper.

  13. Information Foraging in E-Voting

    DEFF Research Database (Denmark)

    Vatrapu, Ravi; Robertson, Scott

    2009-01-01

    with others. Interaction analysis of the case study data consisted of applying Information Foraging Theory to understand participant specific behaviors in searching and browsing. Case study results show skewed time allocation to activities, a tradeoff between enrichment vs. exploitation of search results...

  14. Example of the Smooth Skew Product in the Plane with the One-dimensional Ramified Continuum as the Global Attractor*

    Directory of Open Access Journals (Sweden)

    Efremova L.S.

    2012-08-01

    Full Text Available The example is constructed of the C1-smooth skew product of interval maps possessing the one-dimensional ramified continuum (containing no arcs homeomorphic to the circle with an infinite set of ramification points as the global attractor. L’exemple est construit à partir d’un produit biaisé lisse de classe C1 de transformations d’un intervalle, qui a un continuum unidimensionnel ramifié (ne contenant pas d’arcs homéomorphes à un cercle avec un ensemble infini de points de branchement comme attracteur global.

  15. The subgroups in the special linear group over a skew field that contain the group of diagonal matrices

    International Nuclear Information System (INIS)

    Bui Xuan Hai.

    1990-05-01

    For an arbitrary skew field T we study the lattice of subgroups of the special linear group Γ=SL(n,T) that contain the subgroup Δ-SD(n,T) of diagonal matrices with Dieudonne's determinant equal to 1. We show that the description of these subgroups is standard in the following sense: For any subgroup H,Δ≤H≤Γ there exists a unique unital net such that Γ(σ) ≤H≤N(σ), where Γ(σ) is the net subgroup that corresponds to the net σ and N(σ) is the normalizer of Γ(σ) in Γ. (author). 11 refs

  16. Effects of within-colony competition on body size asymmetries and reproductive skew in a social spider

    DEFF Research Database (Denmark)

    Grinsted, Lena; Bilde, Trine

    2013-01-01

    Reproductive partitioning is a key component of social organization in groups of cooperative organisms. In colonies of permanently social spiders of the genus Stegodyphus less than half of the females reproduce, while all females, including nonreproducers, perform suicidal allo-maternal care. Some...... not increase over the course of the experiment, suggesting that body size variation is shaped at an early stage. This might facilitate task specialization within colonies and ensure colony-level reproductive output by early allocation of reproductive roles. We suggest that reproductive skew in social spiders...

  17. Wave steering effects in anisotropic composite structures: Direct calculation of the energy skew angle through a finite element scheme.

    Science.gov (United States)

    Chronopoulos, D

    2017-01-01

    A systematic expression quantifying the wave energy skewing phenomenon as a function of the mechanical characteristics of a non-isotropic structure is derived in this study. A structure of arbitrary anisotropy, layering and geometric complexity is modelled through Finite Elements (FEs) coupled to a periodic structure wave scheme. A generic approach for efficiently computing the angular sensitivity of the wave slowness for each wave type, direction and frequency is presented. The approach does not involve any finite differentiation scheme and is therefore computationally efficient and not prone to the associated numerical errors. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Comparison of the binary logistic and skewed logistic (Scobit) models of injury severity in motor vehicle collisions.

    Science.gov (United States)

    Tay, Richard

    2016-03-01

    The binary logistic model has been extensively used to analyze traffic collision and injury data where the outcome of interest has two categories. However, the assumption of a symmetric distribution may not be a desirable property in some cases, especially when there is a significant imbalance in the two categories of outcome. This study compares the standard binary logistic model with the skewed logistic model in two cases in which the symmetry assumption is violated in one but not the other case. The differences in the estimates, and thus the marginal effects obtained, are significant when the assumption of symmetry is violated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Mapping Causes and Implications of India’s Skewed Sex Ratio and Poverty problem using Fuzzy & Neutrosophic Relational Maps

    Directory of Open Access Journals (Sweden)

    Gaurav

    2016-08-01

    Full Text Available Numerous studies by different researchers have confirmed that skewed sex ratio is a critical social problem in India. This enduring problem of gender imbalance is the collective result of factors like sex selective abortion, gender discrimination, son preference for the preservation of tribe, emergence of new technologies in medical field and many more factors. Another severe problem to be addressed in India is poverty. Many factors contribute to the perpetuation of poverty such as illiteracy, bad governance, under employment and various other reasons. Despite of India's accelerated growth rate, poverty in India is still prevalent.

  20. A Third Moment Adjusted Test Statistic for Small Sample Factor Analysis.

    Science.gov (United States)

    Lin, Johnny; Bentler, Peter M

    2012-01-01

    Goodness of fit testing in factor analysis is based on the assumption that the test statistic is asymptotically chi-square; but this property may not hold in small samples even when the factors and errors are normally distributed in the population. Robust methods such as Browne's asymptotically distribution-free method and Satorra Bentler's mean scaling statistic were developed under the presumption of non-normality in the factors and errors. This paper finds new application to the case where factors and errors are normally distributed in the population but the skewness of the obtained test statistic is still high due to sampling error in the observed indicators. An extension of Satorra Bentler's statistic is proposed that not only scales the mean but also adjusts the degrees of freedom based on the skewness of the obtained test statistic in order to improve its robustness under small samples. A simple simulation study shows that this third moment adjusted statistic asymptotically performs on par with previously proposed methods, and at a very small sample size offers superior Type I error rates under a properly specified model. Data from Mardia, Kent and Bibby's study of students tested for their ability in five content areas that were either open or closed book were used to illustrate the real-world performance of this statistic.

  1. Time skewing and amplitude nonlinearity mitigation by feedback equalization for 56 Gbps VCSEL-based PAM-4 links

    Science.gov (United States)

    You, Yue; Zhang, Wenjia; Sun, Lin; Du, Jiangbing; Liang, Chenyu; Yang, Fan; He, Zuyuan

    2018-03-01

    The vertical cavity surface emitting laser (VCSEL)-based multimode optical transceivers enabled by pulse amplitude modulation (PAM)-4 will be commercialized in near future to meet the 400-Gbps standard short reach optical interconnects. It is still challenging to achieve over 56/112-Gbps with the multilevel signaling as the multimode property of the device and link would introduce the nonlinear temporal response for the different levels. In this work, we scrutinize the distortions that relates to the multilevel feature of PAM-4 modulation, and propose an effective feedback equalization scheme for 56-Gbps VCSEL-based PAM-4 optical interconnects system to mitigate the distortions caused by eye timing-skew and nonlinear power-dependent noise. Level redistribution at Tx side is theoretically modeled and constructed to achieve equivalent symbol error ratios (SERs) of four levels and improved BER performance. The cause of the eye skewing and the mitigation approach are also simulated at 100-Gbps and experimentally investigated at 56-Gbps. The results indicate more than 2-dB power penalty improvement has been achieved by using such a distortion aware equalizer.

  2. Stock markets volatility spillovers during financial crises: A DCC-MGARCH with skewed-t density approach

    Directory of Open Access Journals (Sweden)

    Dahiru A. Bala

    2017-03-01

    Full Text Available This paper investigates stock returns volatility spillovers in emerging and developed markets (DMs using multivariate-GARCH (MGARCH models and their variants. In addition, we analyse the impacts of global financial crisis (2007–2009 on stock market volatility interactions and modify the BEKK-MGARCH-type models by including financial crisis dummies to assess their impact on volatilities and spillovers. Major findings reveal that correlations among emerging markets (EMs are lower compared with correlations among DMs and increase during financial crises. Furthermore, we detect evidence of volatility spillovers and observe that own-volatility spillovers are higher than cross-volatility spillovers for EMs suggesting that shocks have not been substantially transmitted among EMs compared to DMs. We also find significant asymmetric behaviour in DMs while weak evidence is detected for EMs. Finally, the DCC-with-skewed-t density model provided improved diagnostics compared to other models partly due to its taking into account fat tails and skewed features often present in financial returns.

  3. Implementation of the flow-modulated skew-upwind difference scheme in the COMMIX-1C code: A first assessment

    International Nuclear Information System (INIS)

    Bottoni, M.; Chien, T.H.; Dommanus, H.M.; Sha, W.T.; Shen, Y.; Laster, R.

    1991-01-01

    This paper explains in detail the implementation of the Flow-Modulated Skew-Upwind Difference (FMSUD) scheme in the momentum equation of the COMMIX-1C computer program, where the scheme has been used so far only in the energy equation. Because the three scalar components of the momentum equation are solved in different meshes, staggered with respect to the mesh used for the energy equation and displaced in the respective coordinate direction, implementation of the FMSUD scheme in the momentum equations is by far more demanding than the implementation of a single scalar equation in centered cells. For this reason, a new approach has been devised to treat the problem, from the mathematical viewpoint, in the maximum generality and for all flow conditions, taking into account automatically the direction of the velocity vector and thus choosing automatically the weighting factors to be associated to different cells in the skew-upwind discretization. The new mathematical approach is straightforward for the treatment of inner cells of the fluid-dynamic definition domain, but particular care must be paid to its implementation for boundary cells where the appropriate boundary conditions must be applied. The paper explains the test cases in which the implementation of the FMSUD method has been applied and discusses the quality of the numerical results against the correct solution, when the latter is known. 14 refs., 2 figs., 1 tab

  4. A complete generalized adjustment criterion

    NARCIS (Netherlands)

    Perković, Emilija; Textor, Johannes; Kalisch, Markus; Maathuis, Marloes H.

    2015-01-01

    Covariate adjustment is a widely used approach to estimate total causal effects from observational data. Several graphical criteria have been developed in recent years to identify valid covariates for adjustment from graphical causal models. These criteria can handle multiple causes, latent

  5. Parental Divorce and Children's Adjustment.

    Science.gov (United States)

    Lansford, Jennifer E

    2009-03-01

    This article reviews the research literature on links between parental divorce and children's short-term and long-term adjustment. First, I consider evidence regarding how divorce relates to children's externalizing behaviors, internalizing problems, academic achievement, and social relationships. Second, I examine timing of the divorce, demographic characteristics, children's adjustment prior to the divorce, and stigmatization as moderators of the links between divorce and children's adjustment. Third, I examine income, interparental conflict, parenting, and parents well-being as mediators of relations between divorce and children's adjustment. Fourth, I note the caveats and limitations of the research literature. Finally, I consider notable policies related to grounds for divorce, child support, and child custody in light of how they might affect children s adjustment to their parents divorce. © 2009 Association for Psychological Science.

  6. Application of volume-weighted skew-upwind differencing to thermal and fluid mixing in the cold leg and downcomer of a PWR

    International Nuclear Information System (INIS)

    Chen, F.F.; Miao, C.C.; Chen, B.C.J.; Domanus, H.M.; Lyczkowski, R.W.; Sha, W.T.

    1983-01-01

    Upwind differencing has been the most common numerical scheme used in computational fluid flow and heat transfer in past years. However, the numerical diffusion induced by the use of upwind differencing can be significant in problems involving thermal mixing. Thermal and fluid mixing in a pressurized water reactor during high pressurized coolant injection is a typical example where numerical diffusion is significant. An improved volume-weighted skew-upwind differencing is used here to reduce numerical diffusion without overshooting or undershooting which is the major defect of original skew-upwind differencing proposed by Raithby. The basic concept of volume-weighted skew-upwind differencing is shown. Computations were performed using COMMIX-1B, an extended version of the COMMIX-1A. The experiment analyzed here is test No. 1 of the SAI experiment

  7. Estimating the mean and standard deviation of environmental data with below detection limit observations: Considering highly skewed data and model misspecification.

    Science.gov (United States)

    Shoari, Niloofar; Dubé, Jean-Sébastien; Chenouri, Shoja'eddin

    2015-11-01

    In environmental studies, concentration measurements frequently fall below detection limits of measuring instruments, resulting in left-censored data. Some studies employ parametric methods such as the maximum likelihood estimator (MLE), robust regression on order statistic (rROS), and gamma regression on order statistic (GROS), while others suggest a non-parametric approach, the Kaplan-Meier method (KM). Using examples of real data from a soil characterization study in Montreal, we highlight the need for additional investigations that aim at unifying the existing literature. A number of studies have examined this issue; however, those considering data skewness and model misspecification are rare. These aspects are investigated in this paper through simulations. Among other findings, results show that for low skewed data, the performance of different statistical methods is comparable, regardless of the censoring percentage and sample size. For highly skewed data, the performance of the MLE method under lognormal and Weibull distributions is questionable; particularly, when the sample size is small or censoring percentage is high. In such conditions, MLE under gamma distribution, rROS, GROS, and KM are less sensitive to skewness. Related to model misspecification, MLE based on lognormal and Weibull distributions provides poor estimates when the true distribution of data is misspecified. However, the methods of rROS, GROS, and MLE under gamma distribution are generally robust to model misspecifications regardless of skewness, sample size, and censoring percentage. Since the characteristics of environmental data (e.g., type of distribution and skewness) are unknown a priori, we suggest using MLE based on gamma distribution, rROS and GROS. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. 75 FR 63437 - Trade Adjustment Assistance for Farmers

    Science.gov (United States)

    2010-10-15

    ... DEPARTMENT OF AGRICULTURE Foreign Agricultural Service Trade Adjustment Assistance for Farmers... Service and reviewed by the TAA for Farmers Program Review Committee, comprised of representatives from... assistance in FY 2011. FOR FURTHER INFORMATION CONTACT: Trade Adjustment Assistance for Farmers Program Staff...

  9. 75 FR 43485 - Trade Adjustment Assistance for Farmers

    Science.gov (United States)

    2010-07-26

    ... Service Trade Adjustment Assistance for Farmers AGENCY: Foreign Agricultural Service, USDA. ACTION: Notice... cash benefits. FOR FURTHER INFORMATION CONTACT: Trade Adjustment Assistance for Farmers Staff, FAS... visit the TAA for Farmers' Web site: http://www.fas.usda.gov/itp/taa . Dated: July 14, 2010. John D...

  10. 75 FR 48931 - Trade Adjustment Assistance for Farmers

    Science.gov (United States)

    2010-08-12

    ... DEPARTMENT OF AGRICULTURE Foreign Agricultural Service Trade Adjustment Assistance for Farmers... assistance and cash benefits. FOR FURTHER INFORMATION CONTACT: Trade Adjustment Assistance for Farmers....usda.gov ; or visit the TAA for Farmers' Web site: www.fas.usda.gov/itp/taa . Dated: July 30, 2010...

  11. 75 FR 48642 - Trade Adjustment Assistance for Farmers

    Science.gov (United States)

    2010-08-11

    ... DEPARTMENT OF AGRICULTURE Foreign Agricultural Service Trade Adjustment Assistance for Farmers... benefits. FOR FURTHER INFORMATION CONTACT: Trade Adjustment Assistance for Farmers Program Staff, FAS, USDA... the TAA for Farmers' Web site: http://www.fas.usda.gov/itp/taa . Dated: July 30, 2010. John D. Brewer...

  12. 75 FR 49458 - Trade Adjustment Assistance for Farmers

    Science.gov (United States)

    2010-08-13

    ... DEPARTMENT OF AGRICULTURE Foreign Agricultural Service Trade Adjustment Assistance for Farmers... and cash benefits. FOR FURTHER INFORMATION CONTACT: Trade Adjustment Assistance for Farmers Program....gov ; or visit the TAA for Farmers' Web site: http://www.fas.usda.gov/itp/taa . Dated: August 3, 2010...

  13. 75 FR 49886 - Trade Adjustment Assistance for Farmers

    Science.gov (United States)

    2010-08-16

    ... DEPARTMENT OF AGRICULTURE Foreign Agricultural Service Trade Adjustment Assistance for Farmers... INFORMATION CONTACT: Trade Adjustment Assistance for Farmers Program Staff, FAS, USDA by phone: (202) 720-0638... for Farmers' Web site: http://www.fas.usda.gov/itp/taa . Dated: August 3, 2010. Suzanne Hale, Acting...

  14. 75 FR 42375 - Trade Adjustment Assistance for Farmers

    Science.gov (United States)

    2010-07-21

    ... DEPARTMENT OF AGRICULTURE Foreign Agricultural Service Trade Adjustment Assistance for Farmers... INFORMATION CONTACT: Trade Adjustment Assistance for Farmers Staff, FAS, USDA, by phone: (202) 720-0638, or (202) 690-0633; or by e-mail: [email protected] ; or visit the TAA for Farmers' Web site...

  15. 75 FR 33379 - Railroad Cost Recovery Procedures-Productivity Adjustment; Quarterly Rail Cost Adjustment Factor

    Science.gov (United States)

    2010-06-11

    ... information is contained in the Board's June 14, 2010 decision, which is available on our website at http://www.stb.dot.gov . Copies of the decision may be purchased by contacting the office of Public... Cost Adjustment Factor AGENCY: Surface Transportation Board. [[Page 33380

  16. On the effect of intermittency of turbulence on the parabolic relation between skewness and kurtosis in magnetized plasmas

    International Nuclear Information System (INIS)

    Guszejnov, Dávid; Lazányi, Nóra; Bencze, Attila; Zoletnik, Sándor

    2013-01-01

    This paper is aimed to contribute to the scientific discussions that have been triggered by the experimental observation of a quadratic relation between the kurtosis and skewness of turbulent fluctuations present in fusion plasmas and other nonlinear physical systems. In this paper, we offer a general statistical model which attributes the observed K=aS 2 +b relation to the varying intermittency of the experimental signals. The model is a two random variable model constructed to catch the essential intermittent feature of the real signal. One of the variables is the amplitude of the underlying intermittent event (e.g., turbulent structure) while the other is connected to the intermittency level of the system. This simple model can attribute physical meaning to the a and b coefficients, as they characterize the spatio-temporal statistics of intermittent events. By constructing a particle-conserving Gaussian model for the underlying coherent structures, the experimentally measured a and b coefficients could be adequately reproduced

  17. Skewed distribution of circulating activated natural killer T (NKT) cells in patients with common variable immunodeficiency disorders (CVID).

    Science.gov (United States)

    Carvalho, Karina I; Melo, Karina M; Bruno, Fernanda R; Snyder-Cappione, Jennifer E; Nixon, Douglas F; Costa-Carvalho, Beatriz T; Kallas, Esper G

    2010-09-09

    Common variable immunodeficiency disorder (CVID) is the commonest cause of primary antibody failure in adults and children, and characterized clinically by recurrent bacterial infections and autoimmune manifestations. Several innate immune defects have been described in CVID, but no study has yet investigated the frequency, phenotype or function of the key regulatory cell population, natural killer T (NKT) cells. We measured the frequencies and subsets of NKT cells in patients with CVID and compared these to healthy controls. Our results show a skewing of NKT cell subsets, with CD4+ NKT cells at higher frequencies, and CD8+ NKT cells at lower frequencies. However, these cells were highly activated and expression CD161. The NKT cells had a higher expression of CCR5 and concomitantly expression of CCR5+CD69+CXCR6 suggesting a compensation of the remaining population of NKT cells for rapid effector action.

  18. Progressivity of Taxes, Skeweness of Income Distribution and Violations of the Progressive Principle in Income Tax Systems

    Directory of Open Access Journals (Sweden)

    Edyta Mazurek

    2014-06-01

    Full Text Available Kakwani and Lambert state the three axioms, which should be respected by an equitable tax system. They also proposed a measurement system to evaluate the violations of the axioms. One of the axioms, axiom 2, formulates the progression principle in income tax systems. Vernizzi and Pellegrino improved the alternative index to evaluate violations concerning the progressive command in a tax system. The main aim of this paper is to compare the two indexes in order to evaluate violations of progressive principle in income tax systém using the real data. We also check how the progressivity of taxes and skewness of income distribution affect the measurement of the progressive principle violation.

  19. Physical consequences of the interpretation of the skew part of gμν in Einstein's nonsymmetric unified field theory

    International Nuclear Information System (INIS)

    Voros, J.

    1995-01-01

    The electromagnetic interaction in the Einstein-Infeld-Hoffmann (EIH) equations of motion for charged particles in Einstein's unified field theory (EUFT) is found to be automatically precluded by the conventional identification of the skew part of the fundamental tensor with the Faraday tensor. It is shown that an alternative identification, suggested by observations of Einstein, Bergmann and Papapetrou, would lead to the expected electromagnetic interaction, were it not for the intervention of an infelicitous (radiation) gauge. Therefore, an EIH analysis of EUFT is inconclusive as a test of the physical viability of the theory, and it follows that EUFT cannot be considered necessarily unphysical on the basis of such an analysis. It is concluded that, historically, Einstein's unified field theory was rejected for the wrong reason. 26 refs

  20. An improved model of induction motors for diagnosis purposes - Slot skewing effect and air-gap eccentricity faults

    Energy Technology Data Exchange (ETDEWEB)

    Ghoggal, A.; Zouzou, S.E.; Sahraoui, M. [Laboratoire de genie electrique de Biskra, Departement d' electrotechnique, Universite Mohamed Khider, BP 145, Biskra (Algeria); Razik, H. [Groupe de Recherche en Electrotechnique et Electronique de Nancy, Universite Henri Poincare, Faculte des Sciences et Techniques, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Khezzar, A. [Laboratoire d' Electrotechnique de Constantine, Universite Mentouri, Constantine (Algeria)

    2009-05-15

    This paper describes an improved method for the modeling of axial and radial eccentricities in induction motors (IM). The model is based on an extension of the modified winding function approach (MWFA) which allows for all harmonics of the magnetomotive force (MMF) to be taken into account. It is shown that a plane view of IM gets easily the motor inductances and reduces considerably the calculation process. The described technique includes accurately the slot skewing effect and leads to pure analytical expressions of the inductances in case of radial eccentricity. In order to model the static, dynamic or mixed axial eccentricity, three suitable alternatives are explained. Unlike the previous proposals, the discussed alternatives take into account all the harmonics of the inverse of air-gap function without any development in Fourier series. Simulation results as well as experimental verifications prove the usefulness and the effectiveness of the proposed model. (author)

  1. An improved model of induction motors for diagnosis purposes - Slot skewing effect and air-gap eccentricity faults

    International Nuclear Information System (INIS)

    Ghoggal, A.; Zouzou, S.E.; Razik, H.; Sahraoui, M.; Khezzar, A.

    2009-01-01

    This paper describes an improved method for the modeling of axial and radial eccentricities in induction motors (IM). The model is based on an extension of the modified winding function approach (MWFA) which allows for all harmonics of the magnetomotive force (MMF) to be taken into account. It is shown that a plane view of IM gets easily the motor inductances and reduces considerably the calculation process. The described technique includes accurately the slot skewing effect and leads to pure analytical expressions of the inductances in case of radial eccentricity. In order to model the static, dynamic or mixed axial eccentricity, three suitable alternatives are explained. Unlike the previous proposals, the discussed alternatives take into account all the harmonics of the inverse of air-gap function without any development in Fourier series. Simulation results as well as experimental verifications prove the usefulness and the effectiveness of the proposed model.

  2. Noise-Induced Synchronization among Sub-RF CMOS Analog Oscillators for Skew-Free Clock Distribution

    Science.gov (United States)

    Utagawa, Akira; Asai, Tetsuya; Hirose, Tetsuya; Amemiya, Yoshihito

    We present on-chip oscillator arrays synchronized by random noises, aiming at skew-free clock distribution on synchronous digital systems. Nakao et al. recently reported that independent neural oscillators can be synchronized by applying temporal random impulses to the oscillators [1], [2]. We regard neural oscillators as independent clock sources on LSIs; i. e., clock sources are distributed on LSIs, and they are forced to synchronize through the use of random noises. We designed neuron-based clock generators operating at sub-RF region (CMOS implementation with 0.25-μm CMOS parameters. Through circuit simulations, we demonstrate that i) the clock generators are certainly synchronized by pseudo-random noises and ii) clock generators exhibited phase-locked oscillations even if they had small device mismatches.

  3. Exponential rate of correlation decay for characters in a three-parameter class of toral skew endomorphisms

    International Nuclear Information System (INIS)

    Siboni, S.

    1998-01-01

    A detailed analysis of the correlation decay for characters in a three-parameter class of mappings of the 2-torus onto itself is presented. Being these mappings the natural extension of toral transformations previously considered with regard to a model of modulated diffusion, they show the structure of a skew product between the Bernoulli endomorphism B p (x) and a translation on T 1 . The family of characters for which correlation decay occurs is fully characterized for any choice of the parameters, and the decay is proved to be exponential, with a rate analytically computable. This improves a previous result by W. Parry, provides a lower bound to the spectral radius of a Perron-Frobenius operator introduced by the same author in his proof and answers positively to the conjecture that the poorest is the rational approximation of the coupling parameter of the map the fastest is the decay rate

  4. 75 FR 43840 - Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum Civil Monetary Penalties for...

    Science.gov (United States)

    2010-07-27

    ...-17530; Notice No. 2] RIN 2130-ZA03 Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum... remains at $250. These adjustments are required by the Federal Civil Penalties Inflation Adjustment Act [email protected] . SUPPLEMENTARY INFORMATION: The Federal Civil Penalties Inflation Adjustment Act of 1990...

  5. 5 CFR 838.923 - Cost-of-living adjustment before the death of a retiree.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Cost-of-living adjustment before the... annuity is deemed to order OPM to add to the survivor annuity rate cost-of-living adjustments that occur... adjustments to the survivor annuity rate. (See § 838.735 for information concerning cost-of-living adjustments...

  6. Skewed X-chromosome inactivation plays a crucial role in the onset of symptoms in carriers of Becker muscular dystrophy.

    Science.gov (United States)

    Viggiano, Emanuela; Picillo, Esther; Ergoli, Manuela; Cirillo, Alessandra; Del Gaudio, Stefania; Politano, Luisa

    2017-04-01

    Becker muscular dystrophy (BMD) is an X-linked recessive disorder affecting approximately 1: 18.000 male births. Female carriers are usually asymptomatic, although 2.5-18% may present muscle or heart symptoms. In the present study, the role of the X chromosome inactivation (XCI) on the onset of symptoms in BMD carriers was analysed and compared with the pattern observed in Duchenne muscular dystrophy (DMD) carriers. XCI was determined on the lymphocytes of 36 BMD carriers (both symptomatic and not symptomatic) from 11 families requiring genetic advice at the Cardiomyology and Medical Genetics of the Second University of Naples, using the AR methylation-based assay. Carriers were subdivided into two groups, according to age above or below 50 years. Seven females from the same families known as noncarriers were used as controls. A Student's t-test for nonpaired data was performed to evaluate the differences observed in the XCI values between asymptomatic and symptomatic carriers, and carriers aged above or below 50 years. A Pearson correlation test was used to evaluate the inheritance of the XCI pattern in 19 mother-daughter pairs. The results showed that symptomatic BMD carriers had a skewed XCI with a preferential inactivation of the X chromosome carrying the normal allele, whereas the asymptomatic carriers and controls showed a random XCI. No concordance concerning the XCI pattern was observed between mothers and related daughters. The data obtained in the present study suggest that the onset of symptoms in BMD carriers is related to a skewed XCI, as observed in DMD carriers. Furthermore, they showed no concordance in the XCI pattern inheritance. Copyright © 2017 John Wiley & Sons, Ltd.

  7. A robust and efficient finite volume scheme for the discretization of diffusive flux on extremely skewed meshes in complex geometries

    Science.gov (United States)

    Traoré, Philippe; Ahipo, Yves Marcel; Louste, Christophe

    2009-08-01

    In this paper an improved finite volume scheme to discretize diffusive flux on a non-orthogonal mesh is proposed. This approach, based on an iterative technique initially suggested by Khosla [P.K. Khosla, S.G. Rubin, A diagonally dominant second-order accurate implicit scheme, Computers and Fluids 2 (1974) 207-209] and known as deferred correction, has been intensively utilized by Muzaferija [S. Muzaferija, Adaptative finite volume method for flow prediction using unstructured meshes and multigrid approach, Ph.D. Thesis, Imperial College, 1994] and later Fergizer and Peric [J.H. Fergizer, M. Peric, Computational Methods for Fluid Dynamics, Springer, 2002] to deal with the non-orthogonality of the control volumes. Using a more suitable decomposition of the normal gradient, our scheme gives accurate solutions in geometries where the basic idea of Muzaferija fails. First the performances of both schemes are compared for a Poisson problem solved in quadrangular domains where control volumes are increasingly skewed in order to test their robustness and efficiency. It is shown that convergence properties and the accuracy order of the solution are not degraded even on extremely skewed mesh. Next, the very stable behavior of the method is successfully demonstrated on a randomly distorted grid as well as on an anisotropically distorted one. Finally we compare the solution obtained for quadrilateral control volumes to the ones obtained with a finite element code and with an unstructured version of our finite volume code for triangular control volumes. No differences can be observed between the different solutions, which demonstrates the effectiveness of our approach.

  8. Category effects on stimulus estimation: Shifting and skewed frequency distributions-A reexamination.

    Science.gov (United States)

    Duffy, Sean; Smith, John

    2017-10-18

    Duffy, Huttenlocher, Hedges, and Crawford (Psychonomic Bulletin & Review, 17(2), 224-230, 2010) report on experiments where participants estimate the lengths of lines. These studies were designed to test the category adjustment model (CAM), a Bayesian model of judgments. The authors report that their analysis provides evidence consistent with CAM: that there is a bias toward the running mean and not recent stimuli. We reexamine their data. First, we attempt to replicate their analysis, and we obtain different results. Second, we conduct a different statistical analysis. We find significant recency effects, and we identify several specifications where the running mean is not significantly related to judgment. Third, we conduct tests of auxiliary predictions of CAM. We do not find evidence that the bias toward the mean increases with exposure to the distribution. We also do not find that responses longer than the maximum of the distribution or shorter than the minimum become less likely with greater exposure to the distribution. Fourth, we produce a simulated dataset that is consistent with key features of CAM, and our methods correctly identify it as consistent with CAM. We conclude that the Duffy et al. (2010) dataset is not consistent with CAM. We also discuss how conventions in psychology do not sufficiently reduce the likelihood of these mistakes in future research. We hope that the methods that we employ will be used to evaluate other datasets.

  9. Normal Stress or Adjustment Disorder?

    Science.gov (United States)

    ... disorder is a type of stress-related mental illness that can affect your feelings, thoughts and behaviors. Signs and symptoms of an adjustment disorder can include: Anxiety Poor school or work performance Relationship problems Sadness ...

  10. Time-adjusted variable resistor

    Science.gov (United States)

    Heyser, R. C.

    1972-01-01

    Timing mechanism was developed effecting extremely precisioned highly resistant fixed resistor. Switches shunt all or portion of resistor; effective resistance is varied over time interval by adjusting switch closure rate.

  11. Cost Indexing and Unit Price Adjustments for Construction Materials

    Science.gov (United States)

    2012-10-30

    This project was focused on the assimilation of information regarding unit price adjustment clauses, or PACs, : that are offered for construction materials at the state Departments of Transportation (DOTs). It is intended to : provide the South Carol...

  12. Adjustable chain trees for proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Fonseca, Rasmus

    2012-01-01

    A chain tree is a data structure for changing protein conformations. It enables very fast detection of clashes and free energy potential calculations. A modified version of chain trees that adjust themselves to the changing conformations of folding proteins is introduced. This results in much...... tighter bounding volume hierarchies and therefore fewer intersection checks. Computational results indicate that the efficiency of the adjustable chain trees is significantly improved compared to the traditional chain trees....

  13. Adjusted neutron spectra of STEK cores for reactivity calculations

    International Nuclear Information System (INIS)

    Dekker, J.W.M.; Dragt, J.B.; Janssen, A.J.; Heijboer, R.J.; Klippel, H.Th.

    1978-02-01

    Neutron flux and adjoint flux spectra form a pre-requisite in the analysis of reactivity worth data measured in the STEK facility. First, a survey of all available information about these spectra is given. Next a special application of a general adjustment method is described. This method has been used to obtain adjusted STEK group flux and adjoint flux spectra, starting from calculated spectra. These theoretical spectra were adjusted to reactivity worths of natural boron (nat. B) and 235 U as well as a number of fission reaction rates. As a by-product in this adjustment calculation adjusted fission group cross sections of 235 U were obtained. The results, viz. group fluxes and adjoint fluxes and adjusted fission cross sections of 235 U are given. They have been used for the interpretation of fission product reactivity worth measurements made in STEK

  14. Parentage analysis of Ansell’s mole-rat family groups indicates a high reproductive skew despite relatively relaxed ecological constraints on dispersal

    Czech Academy of Sciences Publication Activity Database

    Patzenhauerová, Hana; Šklíba, J.; Bryja, Josef; Šumbera, R.

    2013-01-01

    Roč. 22, č. 19 (2013), s. 4988-5000 ISSN 0962-1083 R&D Projects: GA AV ČR IAA601410802; GA ČR GAP506/10/0983 Institutional support: RVO:68081766 Keywords : African mole-rat * dispersal * eusociality * Fukomys * mating system * reproductive skew Subject RIV: EH - Ecology, Behaviour Impact factor: 5.840, year: 2013

  15. Skewness of citation impact data and covariates of citation distributions: A large-scale empirical analysis based on Web of Science data

    NARCIS (Netherlands)

    Bornmann, L.; Leydesdorff, L.

    Using percentile shares, one can visualize and analyze the skewness in bibliometric data across disciplines and over time. The resulting figures can be intuitively interpreted and are more suitable for detailed analysis of the effects of independent and control variables on distributions than

  16. A probit- log- skew-normal mixture model for repeated measures data with excess zeros, with application to a cohort study of paediatric respiratory symptoms

    Directory of Open Access Journals (Sweden)

    Johnston Neil W

    2010-06-01

    Full Text Available Abstract Background A zero-inflated continuous outcome is characterized by occurrence of "excess" zeros that more than a single distribution can explain, with the positive observations forming a skewed distribution. Mixture models are employed for regression analysis of zero-inflated data. Moreover, for repeated measures zero-inflated data the clustering structure should also be modeled for an adequate analysis. Methods Diary of Asthma and Viral Infections Study (DAVIS was a one year (2004 cohort study conducted at McMaster University to monitor viral infection and respiratory symptoms in children aged 5-11 years with and without asthma. Respiratory symptoms were recorded daily using either an Internet or paper-based diary. Changes in symptoms were assessed by study staff and led to collection of nasal fluid specimens for virological testing. The study objectives included investigating the response of respiratory symptoms to respiratory viral infection in children with and without asthma over a one year period. Due to sparse data daily respiratory symptom scores were aggregated into weekly average scores. More than 70% of the weekly average scores were zero, with the positive scores forming a skewed distribution. We propose a random effects probit/log-skew-normal mixture model to analyze the DAVIS data. The model parameters were estimated using a maximum marginal likelihood approach. A simulation study was conducted to assess the performance of the proposed mixture model if the underlying distribution of the positive response is different from log-skew normal. Results Viral infection status was highly significant in both probit and log-skew normal model components respectively. The probability of being symptom free was much lower for the week a child was viral positive relative to the week she/he was viral negative. The severity of the symptoms was also greater for the week a child was viral positive. The probability of being symptom free was

  17. Nuclear Data Parameter Adjustment BNL-INL

    International Nuclear Information System (INIS)

    Palmiotti, G.; Hoblit, S.; Herman, M.; Nobre, G.P.A.; Palumbo, A.; Hiruta, H.; Salvatores, M.

    2013-01-01

    This presentation reports on the consistent adjustment of nuclear data parameters performed within a BNL-INL collaboration. The main advantage compared to the classical adjustment of multigroup constants is to provide final nuclear data constrained by the nuclear reaction theory and consistent with both differential and integral measurements. The feasibility of a single-isotope assimilation was tested on a few priority materials ( 23 Na, 56 Fe, 105 Pd, 235,238 U, 239 Pu) using a selection of clean integral experiments. The multi-isotope assimilation is under study for the Big-3 ( 235,238 U, 239 Pu). This work shows that a consistent assimilation is feasible, but there are pitfalls to avoid (e.g. non-linearity, cross section fluctuations) and prerequisites (e.g. realistic covariances, good prior, realistic weighting of differential and integral experiments). Finally, only all experimental information combined with the state of the art modelling may provide a 'right' answer

  18. [Adjustment disorder and DSM-5: A review].

    Science.gov (United States)

    Appart, A; Lange, A-K; Sievert, I; Bihain, F; Tordeurs, D

    2017-02-01

    This paper exposes the complexity and discrete characteristic of the adjustment disorder with reference to its clinical and scientific diagnosis. Even though the disorder occurs in frequent clinical circumstances after important life events, such as mobbing, burn-out, unemployment, divorce or separation, pregnancy denial, surgical operation or cancer, the adjustment disorder is often not considered in the diagnosis since better known disorders with similar symptoms prevail, such as major depression and anxiety disorder. Ten years ago, Bottéro had already noticed that the adjustment disorder diagnosis remained rather uncommon with reference to patients he was working with while Langlois assimilated this disorder with an invisible diagnosis. In order to maximize the data collection, we used the article review below and challenged their surveys and results: National Center for Biotechnology Information (NBCI - Pubmed) for international articles and Cairn.info for French literature. Moreover, we targeted the following keywords on the search engine and used articles, which had been published from 1 February 1975 to 31 January 2015: "adjustment", "adjustment disorder" and the French translation "trouble de l'adaptation". One hundred and ninety-one articles matched our search criteria. However, after a closer analysis, solely 105 articles were selected as being of interest. Many articles were excluded since they were related to non-psychiatric fields induced by the term "adaptation". Indeed, the number of corresponding articles found for the adjustment disorder literally pointed-out the lack of existing literature on that topic in comparison to more known disorders such as anxiety disorder (2661 articles) or major depression (5481 articles). This represents up to 50 times more articles in comparison to the number of articles we found on adjustment disorder and up to 20 times more articles for the eating disorder (1994), although the prevalence is not significantly

  19. Fiscal Adjustment in IMF-Supported Adjustment Programmes: The ...

    African Journals Online (AJOL)

    Fiscal adjustment is an essential element of macro-economic stability and economic growth. Given that economic growth is the most powerful weapon in the fight for higher living standards, poor growth performance in African countries, has been a challenge to economists, policy makers and international development ...

  20. Acculturation, personality, and psychological adjustment.

    Science.gov (United States)

    Ahadi, Stephan A; Puente-Díaz, Rogelio

    2011-12-01

    Two studies investigated relationships between traditional indicators of acculturation, cultural distance, acculturation strategies, and basic dimensions of personality as they pertain to psychological adjustment among Hispanic students. Although personality characteristics have been shown to be important determinants of psychological well-being, acculturation research has put less emphasis on the role of personality in the well-being of immigrants. Hierarchical regression analysis showed that basic dimensions of personality such as extraversion and neuroticism were strongly related to psychological adjustment. Acculturation strategies did not mediate the effect of personality variables, but cultural resistance made a small, independent contribution to the explanation of some aspects of negative psychological adjustment. The implications of the results were discussed.

  1. GPU Parallel Bundle Block Adjustment

    Directory of Open Access Journals (Sweden)

    ZHENG Maoteng

    2017-09-01

    Full Text Available To deal with massive data in photogrammetry, we introduce the GPU parallel computing technology. The preconditioned conjugate gradient and inexact Newton method are also applied to decrease the iteration times while solving the normal equation. A brand new workflow of bundle adjustment is developed to utilize GPU parallel computing technology. Our method can avoid the storage and inversion of the big normal matrix, and compute the normal matrix in real time. The proposed method can not only largely decrease the memory requirement of normal matrix, but also largely improve the efficiency of bundle adjustment. It also achieves the same accuracy as the conventional method. Preliminary experiment results show that the bundle adjustment of a dataset with about 4500 images and 9 million image points can be done in only 1.5 minutes while achieving sub-pixel accuracy.

  2. Turbine blade tip clearance measurement using a skewed dual-beam fiber optic sensor

    Science.gov (United States)

    Ye, De-chao; Duan, Fa-jie; Guo, Hao-tian; Li, Yangzong; Wang, Kai

    2012-08-01

    Optimization and active control of the tip clearance of turbine blades has been identified as a key to improve fuel efficiency, reduce emission, and increase service life of the engine. However, reliable and real-time tip clearance measurement is difficult due to the adverse environmental conditions that are typically found in a turbine. We describe a dual-beam fiber optic measurement system that can measure the tip timing and tip clearance simultaneously. Because the tip timing information is used to calculate the tip clearance, the method is insensitive to the signal intensity variation caused by fluctuations in environmental conditions such as light source instability, contamination, and blade tip imperfection. The system was calibrated and tested using experimental rotors. The test results indicated a high resolution of 4.5 μm and measurement accuracy of ±20 μm over the rotation speed range of 2000 to 10,000 rpm.

  3. Kinematic adjustments to seismic recordings

    Energy Technology Data Exchange (ETDEWEB)

    Telegin, A.N.; Levii, N.V.; Volovik, U.M.

    1981-01-01

    The introduction of kinematic adjustments by adding the displaced blocks is studied theoretically and in test seismograms. The advantage to this method resulting from the weight variation in the trace is demonstrated together with its kinematic drawback. A variation on the displaced block addition method that does not involve realignment of the travel time curves and that has improved amplitude characteristics is proposed.

  4. Adjustment of nursing home quality indicators

    Directory of Open Access Journals (Sweden)

    Hirdes John P

    2010-04-01

    Full Text Available Abstract Background This manuscript describes a method for adjustment of nursing home quality indicators (QIs defined using the Center for Medicaid & Medicare Services (CMS nursing home resident assessment system, the Minimum Data Set (MDS. QIs are intended to characterize quality of care delivered in a facility. Threats to the validity of the measurement of presumed quality of care include baseline resident health and functional status, pattern of comorbidities, and facility case mix. The goal of obtaining a valid facility-level estimate of true quality of care should include adjustment for resident- and facility-level sources of variability. Methods We present a practical and efficient method to achieve risk adjustment using restriction and indirect and direct standardization. We present information on validity by comparing QIs estimated with the new algorithm to one currently used by CMS. Results More than half of the new QIs achieved a "Moderate" validation level. Conclusions Given the comprehensive approach and the positive findings to date, research using the new quality indicators is warranted to provide further evidence of their validity and utility and to encourage their use in quality improvement activities.

  5. On the effect of intermittency of turbulence on the parabolic relation between skewness and kurtosis in magnetized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Guszejnov, Dávid; Lazányi, Nóra [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, Műegyetem rkp. 9., H-1111 Budapest (Hungary); Bencze, Attila; Zoletnik, Sándor [MTA Wigner RCP, EURATOM Association, PO Box 49, H-1525 Budapest (Hungary)

    2013-11-15

    This paper is aimed to contribute to the scientific discussions that have been triggered by the experimental observation of a quadratic relation between the kurtosis and skewness of turbulent fluctuations present in fusion plasmas and other nonlinear physical systems. In this paper, we offer a general statistical model which attributes the observed K=aS{sup 2}+b relation to the varying intermittency of the experimental signals. The model is a two random variable model constructed to catch the essential intermittent feature of the real signal. One of the variables is the amplitude of the underlying intermittent event (e.g., turbulent structure) while the other is connected to the intermittency level of the system. This simple model can attribute physical meaning to the a and b coefficients, as they characterize the spatio-temporal statistics of intermittent events. By constructing a particle-conserving Gaussian model for the underlying coherent structures, the experimentally measured a and b coefficients could be adequately reproduced.

  6. Next generation sequencing reveals skewing of the T and B cell receptor repertoires in patients with Wiskott Aldrich syndrome

    Directory of Open Access Journals (Sweden)

    Amy E O'Connell

    2014-07-01

    Full Text Available The Wiskott Aldrich syndrome (WAS is due to mutations of the WAS gene encoding for the cytoskeletal WAS protein (WASp, leading to abnormal downstream signaling from the T cell and B cell antigen receptors (TCR, BCR. We hypothesized that the impaired signaling through the TCR and BCR in WAS would subsequently lead to aberrations in the immune repertoire of WAS patients. Using next generation sequencing, the T cell receptor beta (TRB and B cell immunoglobulin heavy chain (IGH repertoires of 8 patients with WAS and 6 controls were sequenced. Clonal expansions were identified within memory CD4+ cells, as well as in total, naïve and memory CD8+ cells from WAS patients. In the B cell compartment, WAS patient IGH repertoires were also clonally expanded and showed skewed usage of IGHV and IGHJ genes, and increased usage of IGHG constant genes, compared with controls. To our knowledge, this is the first study that demonstrates significant abnormalities of the immune repertoire in WAS patients using next generation sequencing.

  7. Birth-Order Complementarity and Marital Adjustment.

    Science.gov (United States)

    Vos, Cornelia J. Vanderkooy; Hayden, Delbert J.

    1985-01-01

    Tested the influence of birth-order complementarity on marital adjustment among 327 married women using the Spanier Dyadic Adjustment Scale (1976). Birth-order complementarity was found to be unassociated with marital adjustment. (Author/BL)

  8. Skewed risk perceptions in pregnant women: the case of influenza vaccination.

    Science.gov (United States)

    Bödeker, Birte; Betsch, Cornelia; Wichmann, Ole

    2015-12-29

    's attitude towards vaccination during pregnancy influenced the uptake significantly. Influenza vaccination uptake in pregnant women is low in Germany. Tailored communication strategies for pregnant women should focus especially on changing the perceptions of personal risks regarding influenza and influenza vaccination during pregnancy. Gynaecologists should be made aware about their crucial role in supporting vaccination decision-making of pregnant women and the need to provide relevant information to counteract misconceptions.

  9. Longitudinal Psychosocial Adjustment of Women to Human Papillomavirus Infection.

    Science.gov (United States)

    Hsu, Yu-Yun; Wang, Wei-Ming; Fetzer, Susan Jane; Cheng, Ya-Min; Hsu, Keng-Fu

    2018-05-29

    The aim of this study was to examine the psychosocial adjustment trajectory, focusing on psychological distress, sexual relationships and health care information, as well as factors which have an impact on adjustment on receiving a positive diagnosis of human papillomavirus infection. Human papillomavirus is a common sexually transmitted infection in females. To date, knowledge of the longitudinal psychosocial response to the diagnosis of human papillomavirus is limited. A prospective longitudinal design was conducted with a convenience sample. Women aged 20-65 years old were followed at one, 6 and 12 months after a diagnosis of HPV. Participants completed measures of initial emotional distress and followed-up psychosocial adjustment. A mixed-effects model was applied to analyze the longitudinal changes in psychosocial adjustment. Seventy human papillomavirus positive women participated in the study with nearly 20% of the women reporting emotional distress during their first visit. Mixed-effects model analyses showed that a trajectory of psychosocial adjustment in health care orientation, sexual relationship and psychosocial distress occur from one to 6 months after HPV diagnosis. However, a declining trend from 6-12 months was significant in health care orientation. Initial emotional distress was associated with changes in psychological adjustment. Psychosocial adjustment to human papillomavirus was worse at one month compared with 6 and 12 months after diagnosis. Healthcare providers should offer health information and psychosocial support to women according to their disease progression. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  10. Parenting Perfectionism and Parental Adjustment

    OpenAIRE

    Lee, Meghan A.; Schoppe-Sullivan, Sarah J.; Kamp Dush, Claire M.

    2012-01-01

    The parental role is expected to be one of the most gratifying and rewarding roles in life. As expectations of parenting become ever higher, the implications of parenting perfectionism for parental adjustment warrant investigation. Using longitudinal data from 182 couples, this study examined the associations between societal- and self-oriented parenting perfectionism and new mothers’ and fathers’ parenting self-efficacy, stress, and satisfaction. For mothers, societal-oriented parenting perf...

  11. Signalling chains with probe and adjust learning

    Science.gov (United States)

    Gosti, Giorgio

    2018-04-01

    Many models explain the evolution of signalling in repeated stage games on social networks, differently in this study each signalling game evolves a communication strategy to transmit information across the network. Specifically, I formalise signalling chain games as a generalisation of Lewis' signalling games, where a number of players are placed on a chain network and play a signalling game in which they have to propagate information across the network. I show that probe and adjust learning allows the system to develop communication conventions, but it may temporarily perturb the system out of conventions. Through simulations, I evaluate how long the system takes to evolve a signalling convention and the amount of time it stays in it. This discussion presents a mechanism in which simple players can evolve signalling across a social network without necessarily understanding the entire system.

  12. Adjusted Empirical Likelihood Method in the Presence of Nuisance Parameters with Application to the Sharpe Ratio

    Directory of Open Access Journals (Sweden)

    Yuejiao Fu

    2018-04-01

    Full Text Available The Sharpe ratio is a widely used risk-adjusted performance measurement in economics and finance. Most of the known statistical inferential methods devoted to the Sharpe ratio are based on the assumption that the data are normally distributed. In this article, without making any distributional assumption on the data, we develop the adjusted empirical likelihood method to obtain inference for a parameter of interest in the presence of nuisance parameters. We show that the log adjusted empirical likelihood ratio statistic is asymptotically distributed as the chi-square distribution. The proposed method is applied to obtain inference for the Sharpe ratio. Simulation results illustrate that the proposed method is comparable to Jobson and Korkie’s method (1981 and outperforms the empirical likelihood method when the data are from a symmetric distribution. In addition, when the data are from a skewed distribution, the proposed method significantly outperforms all other existing methods. A real-data example is analyzed to exemplify the application of the proposed method.

  13. Measurement of the Skewness of Elliptic Flow Fluctuations in PbPb Collisions at $\\sqrt{s_{NN}} = 5.02~\\mathrm{TeV}$

    CERN Document Server

    CMS Collaboration

    2017-01-01

    Event-by-event flow harmonics are studied for PbPb collisions at $\\sqrt{s_{NN}} = 5.02~\\mathrm{TeV}$ using the CMS detector at the LHC. Flow harmonic probability distributions $p\\left(v_2\\right)$ are obtained using particles of $0.3 \\leq p_{T} \\leq 3.0~\\mathrm{GeV}/c$ and $\\left|\\eta\\right| \\leq 1.0$ and are unfolded to remove smearing effects from observed azimuthal particle distributions. Cumulant flow harmonics are determined from the moments of $p\\left(v_2\\right)$ and used to estimate the standardized elliptic flow skewness in $5\\%$ wide centrality bins up to $60\\%$. Hydrodynamic models predict that flow fluctuations will lead to a non-Gaussian component in the flow distributions with a negative skew with respect to the reaction plane. A significant negative skewness is observed for all centrality bins as evidenced by a splitting between $v_2\\left\\{4\\right\\}$ and $v_2\\left\\{6\\right\\}$ cumulants. In addition, elliptic power law distribution fits are made to the $p\\left(v_2\\right)$ distributions to infer in...

  14. Parallel tiled Nussinov RNA folding loop nest generated using both dependence graph transitive closure and loop skewing.

    Science.gov (United States)

    Palkowski, Marek; Bielecki, Wlodzimierz

    2017-06-02

    RNA secondary structure prediction is a compute intensive task that lies at the core of several search algorithms in bioinformatics. Fortunately, the RNA folding approaches, such as the Nussinov base pair maximization, involve mathematical operations over affine control loops whose iteration space can be represented by the polyhedral model. Polyhedral compilation techniques have proven to be a powerful tool for optimization of dense array codes. However, classical affine loop nest transformations used with these techniques do not optimize effectively codes of dynamic programming of RNA structure predictions. The purpose of this paper is to present a novel approach allowing for generation of a parallel tiled Nussinov RNA loop nest exposing significantly higher performance than that of known related code. This effect is achieved due to improving code locality and calculation parallelization. In order to improve code locality, we apply our previously published technique of automatic loop nest tiling to all the three loops of the Nussinov loop nest. This approach first forms original rectangular 3D tiles and then corrects them to establish their validity by means of applying the transitive closure of a dependence graph. To produce parallel code, we apply the loop skewing technique to a tiled Nussinov loop nest. The technique is implemented as a part of the publicly available polyhedral source-to-source TRACO compiler. Generated code was run on modern Intel multi-core processors and coprocessors. We present the speed-up factor of generated Nussinov RNA parallel code and demonstrate that it is considerably faster than related codes in which only the two outer loops of the Nussinov loop nest are tiled.

  15. 12 CFR 19.240 - Inflation adjustments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Inflation adjustments. 19.240 Section 19.240... PROCEDURE Civil Money Penalty Inflation Adjustments § 19.240 Inflation adjustments. (a) The maximum amount... Civil Penalties Inflation Adjustment Act of 1990 (28 U.S.C. 2461 note) as follows: ER10NO08.001 (b) The...

  16. 78 FR 12318 - Federal Acquisition Regulation; Submission for OMB Review; Economic Price Adjustment

    Science.gov (United States)

    2013-02-22

    ...; Submission for OMB Review; Economic Price Adjustment AGENCY: Department of Defense (DOD), General Services... economic price adjustment. A notice was published in the Federal Register at 77 FR 69442, on November 19...: Submit comments identified by Information Collection 9000- 0068, Economic Price Adjustment by any of the...

  17. 77 FR 29982 - Federal Acquisition Regulation; Submission for OMB Review; Davis Bacon Act-Price Adjustment...

    Science.gov (United States)

    2012-05-21

    ...; Submission for OMB Review; Davis Bacon Act-Price Adjustment (Actual Method) AGENCY: Department of Defense... previously approved information collection requirement concerning the Davis-Bacon Act price adjustment... Bacon Act-Price Adjustment (Actual Method), by any of the following methods: Regulations.gov : http...

  18. Adjustable extender for instrument module

    International Nuclear Information System (INIS)

    Sevec, J.B.; Stein, A.D.

    1975-01-01

    A blank extender module used to mount an instrument module in front of its console for repair or test purposes has been equipped with a rotatable mount and means for locking the mount at various angles of rotation for easy accessibility. The rotatable mount includes a horizontal conduit supported by bearings within the blank module. The conduit is spring-biased in a retracted position within the blank module and in this position a small gear mounted on the conduit periphery is locked by a fixed pawl. The conduit and instrument mount can be pulled into an extended position with the gear clearing the pawl to permit rotation and adjustment of the instrument

  19. Adjustable Tooling for Bending Brake

    Science.gov (United States)

    Ellis, J. M.

    1986-01-01

    Deep metal boxes and other parts easily fabricated. Adjustable tooling jig for bending brake accommodates spacing blocks and either standard male press-brake die or bar die. Holds spacer blocks, press-brake die, bar window die, or combination of three. Typical bending operations include bending of cut metal sheet into box and bending of metal strip into bracket with multiple inward 90 degree bends. By increasing free space available for bending sheet-metal parts jig makes it easier to fabricate such items as deep metal boxes or brackets with right-angle bends.

  20. BASACF, Integral Neutron Spectra Adjustment and Dosimetry

    International Nuclear Information System (INIS)

    Tichy, Milos

    1996-01-01

    1 - Description of program or function: Adjustment of a neutron spectrum based on integral detector measurements and calculation of an integral dosimetric quantity (integral flux, d.p.a., dose equivalent) and its variance. The program requires measured data (activities and their covariance matrix) and a priori information (spectrum, dosimetry cross sections, integral quantity conversion factor and their covariance matrices). All a priori covariance matrices can be read in from a file prepared by some other code or can be generated by means of three different methods (by subroutines included in the program). A subroutine which can normalize the a priori flux to measured data is also included. The program provides also adjusted dosimetry cross sections (with covariance matrix) so that it can be used for an adjustment of cross sections (or response functions of e.g. Bonner balls) by measurements in well-known neutron spectra. 2 - Method of solution: Bayesian theorem on conditional probability applied to linearized relation between activities, dosimetry cross sections and flux. All probability distributions are supposed to be normal and this supposition leads to minimizing of the same functional as least squares method (STAY'SL). This task is solved by a covariance filter method which avoids any matrix inversion and is numerically robust and stable. 3 - Restrictions on the complexity of the problem: This version can use 45 energy groups and 5 detectors and occupies 310 kB of main memory. This restriction can be modified according to available memory. The covariance matrix of activities is supposed diagonal. A solution is produced for any set of input data but in the case of non-consistent data, when measured activities do not match the a priori flux, the solution is not very meaningful

  1. Perceived parenting and adolescents’ adjustment

    Directory of Open Access Journals (Sweden)

    Joana Jaureguizar

    2018-05-01

    Full Text Available Abstract Adolescence is an important developmental period that is characterised by heightened problems of adjustment. The aim of this study is to analyse adolescents’ adjustment, and to explore the typologies and dimensions of parenting, and thus to determine the relationships between these factors. The sample comprised 1285 adolescent students aged 12 to 16 from the Basque Country (Spain. The students filled out the self-report of the Behavior Assessment System for Children (BASC and the Parental Acceptance-Rejection/Control Questionnaire, (PARQ/Control. Differences by age were found in the adolescents’ school maladjustment and parenting style perception. Moreover, perceptions of little parental warmth were related to higher levels of clinical and school maladjustment, and the lower the parental control, the greater the clinical maladjustment. Finally, the results obtained revealed that the interaction between the mothers’ and fathers’ parenting styles was significant only for clinical maladjustment; those students with neglectful mothers and authoritative fathers presented the highest level of clinical maladjustment, followed by other combinations of neglectful mothers. Furthermore, the students from neglectful and authoritarian families presented the highest levels of school maladjustment, without differences between neglectful and authoritarian or between indulgent and authoritative families.

  2. Culture, emotion regulation, and adjustment.

    Science.gov (United States)

    Matsumoto, David; Yoo, Seung Hee; Nakagawa, Sanae

    2008-06-01

    This article reports differences across 23 countries on 2 processes of emotion regulation--reappraisal and suppression. Cultural dimensions were correlated with country means on both and the relationship between them. Cultures that emphasized the maintenance of social order--that is, those that were long-term oriented and valued embeddedness and hierarchy--tended to have higher scores on suppression, and reappraisal and suppression tended to be positively correlated. In contrast, cultures that minimized the maintenance of social order and valued individual Affective Autonomy and Egalitarianism tended to have lower scores on Suppression, and Reappraisal and Suppression tended to be negatively correlated. Moreover, country-level emotion regulation was significantly correlated with country-level indices of both positive and negative adjustment. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

  3. Inactive Gingipains from P. gingivalis Selectively Skews T Cells toward a Th17 Phenotype in an IL-6 Dependent Manner

    Directory of Open Access Journals (Sweden)

    Jan Potempa

    2017-04-01

    , this study revealed a previously undisclosed role of gingipain activity in the process of Th17 differentiation reliant on blocking signaling through IL-6. Since inactivation of gingipains accelerates the skewing of T cells toward Th17 cells, which are detrimental in periodontitis, IL-6 signaling may serve as an attractive target for treatment of the disease.

  4. Skewed Sociolinguistic Awareness of a Native Non-standard Dialect: Evidence from the Cypriot Greek Writing of Greek Cypriot Students

    Directory of Open Access Journals (Sweden)

    Ioli Ayiomamitou

    2017-11-01

    Cypriot students have a skewed sociolinguistic awareness of variation within their first dialect and a distorted impression of their own everyday language. We argue that the portrayal of CG in its basilectal form was performed intentionally by students in an effort to distance themselves from a socially constructed identity of a rural, uneducated, and stigmatized non-standard-dialect speaker. The study is of international relevance as it deals with sociolinguistic issues that pertain to all bidialectal speakers.

  5. Inactive Gingipains from P. gingivalis Selectively Skews T Cells toward a Th17 Phenotype in an IL-6 Dependent Manner.

    Science.gov (United States)

    Glowczyk, Izabela; Wong, Alicia; Potempa, Barbara; Babyak, Olena; Lech, Maciej; Lamont, Richard J; Potempa, Jan; Koziel, Joanna

    2017-01-01

    revealed a previously undisclosed role of gingipain activity in the process of Th17 differentiation reliant on blocking signaling through IL-6. Since inactivation of gingipains accelerates the skewing of T cells toward Th17 cells, which are detrimental in periodontitis, IL-6 signaling may serve as an attractive target for treatment of the disease.

  6. A comparison of methods to handle skew distributed cost variables in the analysis of the resource consumption in schizophrenia treatment.

    Science.gov (United States)

    Kilian, Reinhold; Matschinger, Herbert; Löeffler, Walter; Roick, Christiane; Angermeyer, Matthias C

    2002-03-01

    Transformation of the dependent cost variable is often used to solve the problems of heteroscedasticity and skewness in linear ordinary least square regression of health service cost data. However, transformation may cause difficulties in the interpretation of regression coefficients and the retransformation of predicted values. The study compares the advantages and disadvantages of different methods to estimate regression based cost functions using data on the annual costs of schizophrenia treatment. Annual costs of psychiatric service use and clinical and socio-demographic characteristics of the patients were assessed for a sample of 254 patients with a diagnosis of schizophrenia (ICD-10 F 20.0) living in Leipzig. The clinical characteristics of the participants were assessed by means of the BPRS 4.0, the GAF, and the CAN for service needs. Quality of life was measured by WHOQOL-BREF. A linear OLS regression model with non-parametric standard errors, a log-transformed OLS model and a generalized linear model with a log-link and a gamma distribution were used to estimate service costs. For the estimation of robust non-parametric standard errors, the variance estimator by White and a bootstrap estimator based on 2000 replications were employed. Models were evaluated by the comparison of the R2 and the root mean squared error (RMSE). RMSE of the log-transformed OLS model was computed with three different methods of bias-correction. The 95% confidence intervals for the differences between the RMSE were computed by means of bootstrapping. A split-sample-cross-validation procedure was used to forecast the costs for the one half of the sample on the basis of a regression equation computed for the other half of the sample. All three methods showed significant positive influences of psychiatric symptoms and met psychiatric service needs on service costs. Only the log- transformed OLS model showed a significant negative impact of age, and only the GLM shows a significant

  7. Theory of Work Adjustment Personality Constructs.

    Science.gov (United States)

    Lawson, Loralie

    1993-01-01

    To measure Theory of Work Adjustment personality and adjustment style dimensions, content-based scales were analyzed for homogeneity and successively reanalyzed for reliability improvement. Three sound scales were developed: inflexibility, activeness, and reactiveness. (SK)

  8. 12 CFR 313.55 - Salary adjustments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Salary adjustments. 313.55 Section 313.55 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE PROCEDURES FOR CORPORATE DEBT COLLECTION Salary Offset § 313.55 Salary adjustments. Any negative adjustment to pay arising...

  9. Do fair value adjustments influence dividend policy?

    NARCIS (Netherlands)

    Goncharov, I.; van Triest, S.

    2011-01-01

    We examine the impact of positive fair value adjustments on dividend policy. If fair value adjustments are transitory in nature and managers are able to assess their implications for future earnings, fair value adjustments in net income is expected to have no distribution consequences. However,

  10. 24 CFR 5.611 - Adjusted income.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Adjusted income. 5.611 Section 5... Serving Persons with Disabilities: Family Income and Family Payment; Occupancy Requirements for Section 8 Project-Based Assistance Family Income § 5.611 Adjusted income. Adjusted income means annual income (as...

  11. 12 CFR 1780.80 - Inflation adjustments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Inflation adjustments. 1780.80 Section 1780.80... DEVELOPMENT RULES OF PRACTICE AND PROCEDURE RULES OF PRACTICE AND PROCEDURE Civil Money Penalty Inflation Adjustments § 1780.80 Inflation adjustments. The maximum amount of each civil money penalty within OFHEO's...

  12. 7 CFR 1744.64 - Budget adjustment.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Budget adjustment. 1744.64 Section 1744.64... Disbursement of Funds § 1744.64 Budget adjustment. (a) If more funds are required than are available in a budget account, the borrower may request RUS's approval of a budget adjustment to use funds from another...

  13. 75 FR 71069 - Adopted Adjustments to Alternative Site Framework

    Science.gov (United States)

    2010-11-22

    ... general-purpose FTZ sites. The adjustments stem from a staff proposal published in August 2010 (75 FR... information on each site's activated space. (2) For ASF applications, allow two general options for...-purpose FTZ adjacency requirement), has appropriate zoning (i.e., can accommodate the types of uses...

  14. An adjustable linear Halbach array

    Energy Technology Data Exchange (ETDEWEB)

    Hilton, J.E., E-mail: James.Hilton@csiro.au [CSIRO Mathematics, Informatics and Statistics, Clayton South, VIC 3169 (Australia); McMurry, S.M. [School of Physics, Trinity College, Dublin (Ireland)

    2012-07-15

    The linear Halbach array is a well-known planar magnetic structure capable, in the idealized case, of generating a one-sided magnetic field. We show that such a field can be created from an array of uniformly magnetized rods, and rotating these rods in an alternating fashion can smoothly transfer the resultant magnetic field through the plane of the device. We examine an idealized model composed of infinite line dipoles and carry out computational simulations on a realizable device using a magnetic boundary element method. Such an arrangement can be used for an efficient latching device, or to produce a highly tunable field in the space above the device. - Highlights: Black-Right-Pointing-Pointer We model an adjustable 'one-sided' flux sheet made up of a series of dipolar magnetic field sources. Black-Right-Pointing-Pointer We show that magnetic field can be switched from one side of sheet to other by a swap rotation of each of magnetic sources. Black-Right-Pointing-Pointer Investigations show that such an arrangement is practical and can easily be fabricated. Black-Right-Pointing-Pointer The design has a wide range of potential applications.

  15. Control of Adjustable Compliant Actuators

    Directory of Open Access Journals (Sweden)

    Berno J.E. Misgeld

    2014-05-01

    Full Text Available Adjustable compliance or variable stiffness actuators comprise an additional element to elastically decouple the actuator from the load and are increasingly applied to human-centered robotic systems. The advantages of such actuators are of paramount importance in rehabilitation robotics, where requirements demand safe interaction between the therapy system and the patient. Compliant actuator systems enable the minimization of large contact forces arising, for example, from muscular spasticity and have the ability to periodically store and release energy in cyclic movements. In order to overcome the loss of bandwidth introduced by the elastic element and to guarantee a higher range in force/torque generation, new actuator designs consider variable or nonlinear stiffness elements, respectively. These components cannot only be adapted to the walking speed or the patient condition, but also entail additional challenges for feedback control. This paper introduces a novel design method for an impedance-based controller that fulfills the control objectives and compares the performance and robustness to a classical cascaded control approach. The new procedure is developed using a non-standard positive-real Η2 controller design and is applied to a loop-shaping approach. Robust norm optimal controllers are designed with regard to the passivity of the actuator load-impedance transfer function and the servo control problem. Classical cascaded and positive-real Η2 controller designs are validated and compared in simulations and in a test bench using a passive elastic element of varying stiffness.

  16. An adjustable linear Halbach array

    International Nuclear Information System (INIS)

    Hilton, J.E.; McMurry, S.M.

    2012-01-01

    The linear Halbach array is a well-known planar magnetic structure capable, in the idealized case, of generating a one-sided magnetic field. We show that such a field can be created from an array of uniformly magnetized rods, and rotating these rods in an alternating fashion can smoothly transfer the resultant magnetic field through the plane of the device. We examine an idealized model composed of infinite line dipoles and carry out computational simulations on a realizable device using a magnetic boundary element method. Such an arrangement can be used for an efficient latching device, or to produce a highly tunable field in the space above the device. - Highlights: ► We model an adjustable ‘one-sided’ flux sheet made up of a series of dipolar magnetic field sources. ► We show that magnetic field can be switched from one side of sheet to other by a swap rotation of each of magnetic sources. ► Investigations show that such an arrangement is practical and can easily be fabricated. ► The design has a wide range of potential applications.

  17. EVALUATION OF A NEW MEAN SCALED AND MOMENT ADJUSTED TEST STATISTIC FOR SEM.

    Science.gov (United States)

    Tong, Xiaoxiao; Bentler, Peter M

    2013-01-01

    Recently a new mean scaled and skewness adjusted test statistic was developed for evaluating structural equation models in small samples and with potentially nonnormal data, but this statistic has received only limited evaluation. The performance of this statistic is compared to normal theory maximum likelihood and two well-known robust test statistics. A modification to the Satorra-Bentler scaled statistic is developed for the condition that sample size is smaller than degrees of freedom. The behavior of the four test statistics is evaluated with a Monte Carlo confirmatory factor analysis study that varies seven sample sizes and three distributional conditions obtained using Headrick's fifth-order transformation to nonnormality. The new statistic performs badly in most conditions except under the normal distribution. The goodness-of-fit χ(2) test based on maximum-likelihood estimation performed well under normal distributions as well as under a condition of asymptotic robustness. The Satorra-Bentler scaled test statistic performed best overall, while the mean scaled and variance adjusted test statistic outperformed the others at small and moderate sample sizes under certain distributional conditions.

  18. Effect of length to thickness ratio on free vibration analysis of thick fiber reinforced plastic skew cross-ply laminate with circular cutout

    Science.gov (United States)

    Srividya, K.; Reddy, Ch. Kishore; Sumanth, Ch. Mohan; Krishnaiah, P. Gopala; Kishan, V. Mallikharjuna

    2018-04-01

    The present investigation deals with the free vibration analysis of a thick four-layered symmetric cross-ply skew laminated composite plate with a circular cutout. Three dimensional finite element models (FEM) which use the elasticity theory for the determination of stiffness matrices are modeled in ANSYS software to evaluate first five natural frequencies of the laminate. The variations of the first five natural frequencies with respect to length to thickness ratio (S) for different diameter to length ratios (d/l) are presented. It is observed that, the natural frequencies decreases with increase of thickness ratio(S).

  19. p-hacking by post hoc selection with multiple opportunities: Detectability by skewness test?: Comment on Simonsohn, Nelson, and Simmons (2014).

    Science.gov (United States)

    Ulrich, Rolf; Miller, Jeff

    2015-12-01

    Simonsohn, Nelson, and Simmons (2014) have suggested a novel test to detect p-hacking in research, that is, when researchers report excessive rates of "significant effects" that are truly false positives. Although this test is very useful for identifying true effects in some cases, it fails to identify false positives in several situations when researchers conduct multiple statistical tests (e.g., reporting the most significant result). In these cases, p-curves are right-skewed, thereby mimicking the existence of real effects even if no effect is actually present. (c) 2015 APA, all rights reserved).

  20. Sexual Adjustment in the Handicapped

    Science.gov (United States)

    Glass, Dorothea D.; Padrone, Frank J.

    1978-01-01

    Major topics discussed include introduction and background of the growing recognition of sexual feelings and concerns of the handicapped, attitudes and assumptions resulting from lack of information for both the handicapped and the various disciplines that serve them, medical and psychological aspects of sexual response, and services for the…

  1. Information Rx Program Requires More Promotion, More Support and Some Adjustment. A Review of: Meeks, K. (2009. Information Rx: Promotion and utilization by Georgia librarians and the Georgia American College of Physicians. Journal of Consumer Health on the Internet, 13, 129-134.

    Directory of Open Access Journals (Sweden)

    Matthew Thomas

    2010-12-01

    Full Text Available Objective – To determine the level of awareness of the Information Rx program by Georgia librarians and Georgia American College of Physicians (GACP members, and the use of Information Rx pads, with which physicians would “prescribe” information for their patients.Design – Descriptive (surveys and interviews.Setting – Georgia, U.S. Surveys were distributed and responded to online. The face-to-face interview locations were not specified.Subjects – One survey, which was provided to the Georgia American College of Physicians (GACP membership including internal medicine physicians and medical students interested in internal medicine, had 46 respondents. The second survey was sent to librarians who were members of the Georgia Public Library Service (GPLS and the Georgia Health Sciences Library Association (GHSLA. There were 72 public librarians, 14 hospital librarians and 13 academic medical librarians who responded (as well as 6 not specified in the article. A select group of four medical librarians was chosen for more in-depth interviews. The number of surveys sent out was not provided.Methods – Two online surveys, one for physicians and one for librarians, were administered. No information concerning response rate was provided. Face-to-face interviews with four academic medical librarians were conducted. No further information about the interviewing process was provided such as who conducted the interviews, methods used to ensure objectivity or consistency, or where the interviews were conducted.Main Results – Out of 46 GACP survey respondents, only 4 were familiar with the Information Rx program and only 2 of those had used the information Rx pads, neither of whom had referred anyone to a library for further assistance. The two who had not used the pads were either too busy or didn’t understand the program well enough. Of 105 librarian survey respondents, 46 had heard of Information Rx, 37 had received Information Rx promotional

  2. Depletion calculations of adjuster rods in Darlington

    Energy Technology Data Exchange (ETDEWEB)

    Arsenault, B.; Tsang, K., E-mail: benoit.arsenault@amecfw.com, E-mail: kwok.tsang@amecfw.com [AMEC Foster Wheeler, Toronto, ON (Canada)

    2015-07-01

    This paper describes the simulation methodology and reactivity worth calculated for aged adjuster rods in the Darlington core. ORIGEN-S IST was applied to simulate the isotope transmutation process of the stainless steel and titanium adjusters. The compositions were used in DRAGON-IST to calculate the change in incremental properties of aged adjusters. Pre-simulations of the reactivity worth of the stainless steel and titanium adjusters in Darlington were performed using RFSP-IST and the results showed that the titanium adjuster rods exhibit faster reactivity-worth drop than that of stainless steel rods. (author)

  3. Artificial muscles with adjustable stiffness

    International Nuclear Information System (INIS)

    Mutlu, Rahim; Alici, Gursel

    2010-01-01

    This paper reports on a stiffness enhancement methodology based on using a suitably designed contact surface with which cantilevered-type conducting polymer bending actuators are in contact during operation. The contact surface constrains the bending behaviour of the actuators. Depending on the topology of the contact surface, the resistance of the polymer actuators to deformation, i.e. stiffness, is varied. As opposed to their predecessors, these polymer actuators operate in air. Finite element analysis and modelling are used to quantify the effect of the contact surface on the effective stiffness of a trilayer cantilevered beam, which represents a one-end-free, the-other-end-fixed polypyrrole (PPy) conducting polymer actuator under a uniformly distributed load. After demonstrating the feasibility of the adjustable stiffness concept, experiments were conducted to determine the stiffness of bending-type conducting polymer actuators in contact with a range (20–40 mm in radius) of circular contact surfaces. The numerical and experimental results presented demonstrate that the stiffness of the actuators can be varied using a suitably profiled contact surface. The larger the radius of the contact surface is, the higher is the stiffness of the polymer actuators. The outcomes of this study suggest that, although the stiffness of the artificial muscles considered in this study is constant for a given geometric size, and electrical and chemical operation conditions, it can be changed in a nonlinear fashion to suit the stiffness requirement of a considered application. The stiffness enhancement methodology can be extended to other ionic-type conducting polymer actuators

  4. Can structural adjustment work for women farmers.

    Science.gov (United States)

    Mehra, R

    1991-12-01

    This article discusses the impact of structural adjustment programs (SAPs) on women farmers in developing countries. SAPs aim to improve economic efficiency and promote more rapid economic growth. SAPs are introduced in two phases. The first phase involves short-term loans with the condition that the country adopt monetary restraints and currency devaluation measures. In the second phase, long-term loans are given with the provision that the country deregulate their economy and open up markets. The agricultural sector is affected by SAPs because of their importance in employment, income generation, and export earnings. SAPs result in lower farm commodity prices due to currency devaluations and in removal of subsidies, which results in market-sensitive pricing or higher food prices. The impact of SAPs on agriculture vary between countries. In Morocco and Algeria, agriculture expanded under SAPs. In Indonesia, Bolivia, Costa Rica, and Mexico, the agriculture stagnated or declined. Agricultural growth was slowest in Africa. SAPs were somewhat successful in increasing agricultural exports. Food production grew slowly in many adjusting countries. Blame for failures of SAPs has been placed on government failure to implement reforms properly and overly optimistic assumptions about the timing of productive gains. Little attention has focused on the constraints facing women farmers, who are a large proportion of farmers, particularly in sub-Saharan Africa. This article focuses on the issues of limited access to resources, credit, agricultural extension and information, land ownership, education, and time as constraints to women farmers. Women also must ensure household food security. For SAPs to work effectively, complementary policies must be implemented that reallocate available productive resources and new technologies to women and that deal with women's constraints.

  5. Diagnosis-Based Risk Adjustment for Medicare Capitation Payments

    Science.gov (United States)

    Ellis, Randall P.; Pope, Gregory C.; Iezzoni, Lisa I.; Ayanian, John Z.; Bates, David W.; Burstin, Helen; Ash, Arlene S.

    1996-01-01

    Using 1991-92 data for a 5-percent Medicare sample, we develop, estimate, and evaluate risk-adjustment models that utilize diagnostic information from both inpatient and ambulatory claims to adjust payments for aged and disabled Medicare enrollees. Hierarchical coexisting conditions (HCC) models achieve greater explanatory power than diagnostic cost group (DCG) models by taking account of multiple coexisting medical conditions. Prospective models predict average costs of individuals with chronic conditions nearly as well as concurrent models. All models predict medical costs far more accurately than the current health maintenance organization (HMO) payment formula. PMID:10172666

  6. Flexible mixture modeling via the multivariate t distribution with the Box-Cox transformation: an alternative to the skew-t distribution.

    Science.gov (United States)

    Lo, Kenneth; Gottardo, Raphael

    2012-01-01

    Cluster analysis is the automated search for groups of homogeneous observations in a data set. A popular modeling approach for clustering is based on finite normal mixture models, which assume that each cluster is modeled as a multivariate normal distribution. However, the normality assumption that each component is symmetric is often unrealistic. Furthermore, normal mixture models are not robust against outliers; they often require extra components for modeling outliers and/or give a poor representation of the data. To address these issues, we propose a new class of distributions, multivariate t distributions with the Box-Cox transformation, for mixture modeling. This class of distributions generalizes the normal distribution with the more heavy-tailed t distribution, and introduces skewness via the Box-Cox transformation. As a result, this provides a unified framework to simultaneously handle outlier identification and data transformation, two interrelated issues. We describe an Expectation-Maximization algorithm for parameter estimation along with transformation selection. We demonstrate the proposed methodology with three real data sets and simulation studies. Compared with a wealth of approaches including the skew-t mixture model, the proposed t mixture model with the Box-Cox transformation performs favorably in terms of accuracy in the assignment of observations, robustness against model misspecification, and selection of the number of components.

  7. Cost per quality-adjusted life year and disability-adjusted life years: the need for a new paradigm.

    Science.gov (United States)

    Bevan, Gwyn; Hollinghurst, Sandra

    2003-08-01

    Two different paradigms have been proposed for setting priorities for access to healthcare: cost per quality-adjusted life year based on interventions, and disability-adjusted life years based on the burden of disease in a population. These formal paradigms make explicit the assumptions made implicitly every day in delivering and hence rationing access to healthcare. This paper outlines each paradigm's methodological problems and argues that each paradigm is incomplete in terms of providing the information necessary for making budgetary decisions on healthcare. It argues that a scientific revolution is required to create a new paradigm by combining the strengths of each.

  8. T-cell receptor Vβ skewing frequently occurs in refractory cytopenia of childhood and is associated with an expansion of effector cytotoxic T cells: a prospective study by EWOG-MDS

    International Nuclear Information System (INIS)

    Aalbers, A M; Heuvel-Eibrink, M M van den; Baumann, I; Beverloo, H B; Driessen, G J; Dworzak, M; Fischer, A; Göhring, G; Hasle, H; Locatelli, F; De Moerloose, B; Noellke, P; Schmugge, M; Stary, J; Yoshimi, A; Zecca, M; Zwaan, C M; Dongen, J J M van; Pieters, R; Niemeyer, C M; Velden, V H J van der; Langerak, A W

    2014-01-01

    Immunosuppressive therapy (IST), consisting of antithymocyte globulin and cyclosporine A, is effective in refractory cytopenia of childhood (RCC), suggesting that, similar to low-grade myelodysplastic syndromes in adult patients, T lymphocytes are involved in suppressing hematopoiesis in a subset of RCC patients. However, the potential role of a T-cell-mediated pathophysiology in RCC remains poorly explored. In a cohort of 92 RCC patients, we prospectively assessed the frequency of T-cell receptor (TCR) β-chain variable (Vβ) domain skewing in bone marrow and peripheral blood by heteroduplex PCR, and analyzed T-cell subsets in peripheral blood by flow cytometry. TCRVβ skewing was present in 40% of RCC patients. TCRVβ skewing did not correlate with bone marrow cellularity, karyotype, transfusion history, HLA-DR15 or the presence of a PNH clone. In 28 patients treated with IST, TCRVβ skewing was not clearly related with treatment response. However, TCRVβ skewing did correlate with a disturbed CD4 + /CD8 + T-cell ratio, a reduction in naive CD8 + T cells, an expansion of effector CD8 + T cells and an increase in activated CD8 + T cells (defined as HLA-DR + , CD57 + or CD56 + ). These data suggest that T lymphocytes contribute to RCC pathogenesis in a proportion of patients, and provide a rationale for treatment with IST in selected patients with RCC

  9. TREE AGE AS ADJUSTMENT FACTOR TO NDVI

    OpenAIRE

    Elias Fernando Berra; Denise Cybis Fontana; Tatiana Mora Kuplich

    2018-01-01

    ABSTRACT This study aimed to increase satellite-derived Normalized Difference Vegetation Index (NDVI) sensitivity to biophysical parameters changes with aid of a forest age-based adjustment factor. This factor is defined as a ratio between stand age and age of rotation, which value multiplied by Landsat-5/TM-derived NDVI generated the so-called adjusted index NDVI_a. Soil Adjusted Vegetation Index (SAVI) was also calculated. The relationship between these vegetation indices (VI) with Eucalypt...

  10. Neutron spectrum adjustment. The role of covariances

    International Nuclear Information System (INIS)

    Remec, I.

    1992-01-01

    Neutron spectrum adjustment method is shortly reviewed. Practical example dealing with power reactor pressure vessel exposure rates determination is analysed. Adjusted exposure rates are found only slightly affected by the covariances of measured reaction rates and activation cross sections, while the multigroup spectra covariances were found important. Approximate spectra covariance matrices, as suggested in Astm E944-89, were found useful but care is advised if they are applied in adjustments of spectra at locations without dosimetry. (author) [sl

  11. Case-Mix Adjustment of the Bereaved Family Survey.

    Science.gov (United States)

    Kutney-Lee, Ann; Carpenter, Joan; Smith, Dawn; Thorpe, Joshua; Tudose, Alina; Ersek, Mary

    2018-01-01

    Surveys of bereaved family members are increasingly being used to evaluate end-of-life (EOL) care and to measure organizational performance in EOL care quality. The Bereaved Family Survey (BFS) is used to monitor EOL care quality and benchmark performance in the Veterans Affairs (VA) health-care system. The objective of this study was to develop a case-mix adjustment model for the BFS and to examine changes in facility-level scores following adjustment, in order to provide fair comparisons across facilities. We conducted a cross-sectional secondary analysis of medical record and survey data from veterans and their family members across 146 VA medical centers. Following adjustment using model-based propensity weighting, the mean change in the BFS-Performance Measure score across facilities was -0.6 with a range of -2.6 to 0.6. Fifty-five (38%) facilities changed within ±0.5 percentage points of their unadjusted score. On average, facilities that benefited most from adjustment cared for patients with greater comorbidity burden and were located in urban areas in the Northwest and Midwestern regions of the country. Case-mix adjustment results in minor changes to facility-level BFS scores but allows for fairer comparisons of EOL care quality. Case-mix adjustment of the BFS positions this National Quality Forum-endorsed measure for use in public reporting and internal quality dashboards for VA leadership and may inform the development and refinement of case-mix adjustment models for other surveys of bereaved family members.

  12. Suicidal Tendency Among Adolescents With Adjustment Disorder.

    Science.gov (United States)

    Ferrer, Laia; Kirchner, Teresa

    2015-01-01

    Adolescents with adjustment disorder (AD) are at risk of presenting suicidal symptoms. Certain personality traits are linked to suicidal tendencies. There is a lack of information about the link between suicide and personality patterns in adolescents with AD. To identify the personality characteristics that predispose to or prevent the development of suicidal ideation and behavior among adolescents with AD. We recruited 108 adolescents with AD at a public mental health center near Barcelona (Spain). They were administered the Inventario de Riesgo Suicida para Adolescentes (IRIS) to assess suicidal symptoms, as well as the Millon Adolescent Clinical Inventory (MACI) and the 16PF Adolescent Personality Questionnaire (16PF-APQ) to appraise personality features. Doleful personality emerged as the principal risk for suicidal symptoms. The conforming personality pattern exerted a protective effect, and emotional stability was associated with low levels of suicidal tendencies. Among the Big Five factors, anxiety had the highest explanatory power for suicidal tendencies. Certain personality characteristics are associated with heightened or reduced risk of suicidal tendencies in adolescents with AD. Their identification is important for clinicians designing treatment programs for these patients.

  13. Heavy metal mediated innate immune responses of the Indian green frog, Euphlyctis hexadactylus (Anura: Ranidae): Cellular profiles and associated Th1 skewed cytokine response

    International Nuclear Information System (INIS)

    Jayawardena, Uthpala A.; Ratnasooriya, Wanigasekara D.; Wickramasinghe, Deepthi D.; Udagama, Preethi V.

    2016-01-01

    Immune cell and cytokine profiles in relation to metal exposure though much studied in mammals has not been adequately investigated in amphibians, due mainly to lack of suitable reagents for cytokine profiling in non-model species. However, interspecies cross reactivity of cytokines permitted us to assay levels of IFNγ, TNFα, IL6 and IL10in a common anuran, the Indian green frog (Euphlyctis hexadactylus), exposed to heavy metals (Cd, Cr, Cu, Zn and Pb, at ~ 5 ppm each) under field and laboratory settings in Sri Lanka. Enumeration of immune cells in blood and melanomacrophages in the liver, assay of serum and hepatic cytokines, and Th1/Th2 cytokine polarisation were investigated. Immune cell counts indicated overall immunosuppression with decreasing total WBC and splenocyte counts while neutrophil/lymphocyte ratio increased with metal exposure, indicating metal mediated stress. Serum IL6 levels of metal exposed frogs reported the highest (~ 9360 pg/mL) of all cytokines tested. Significantly elevated IFNγ production (P < 0.05) was evident in heavy metal exposed frogs. Th1/Th2 cytokine ratio in both serum and liver tissue homogenates was Th1 skewed due to significantly higher production of pro-inflammatory cytokines, IFNγ in serum and TNFα in the liver (P < 0.01).Metal mediated aggregations of melanomacrophages in the liver were positively and significantly (P < 0.05) correlated with the hepatic expression of TNFα, IL6 and IL10 activity. Overall, Th1 skewed response may well be due to oxidative stress mediated nuclear factor κ-light chain enhancer of activated B cells (NFκB) which enhances the transcription of pro-inflammatory cytokines. Xenobiotic stress has recently imposed an unprecedented level of threat to wildlife, particularly to sensitive species such as amphibians. Therefore, understanding the interactions between physiological stress and related immune responses is fundamental to conserve these environmental sentinels in the face of emerging eco

  14. Heavy metal mediated innate immune responses of the Indian green frog, Euphlyctis hexadactylus (Anura: Ranidae): Cellular profiles and associated Th1 skewed cytokine response

    Energy Technology Data Exchange (ETDEWEB)

    Jayawardena, Uthpala A.; Ratnasooriya, Wanigasekara D.; Wickramasinghe, Deepthi D.; Udagama, Preethi V., E-mail: dappvr@yahoo.com

    2016-10-01

    Immune cell and cytokine profiles in relation to metal exposure though much studied in mammals has not been adequately investigated in amphibians, due mainly to lack of suitable reagents for cytokine profiling in non-model species. However, interspecies cross reactivity of cytokines permitted us to assay levels of IFNγ, TNFα, IL6 and IL10in a common anuran, the Indian green frog (Euphlyctis hexadactylus), exposed to heavy metals (Cd, Cr, Cu, Zn and Pb, at ~ 5 ppm each) under field and laboratory settings in Sri Lanka. Enumeration of immune cells in blood and melanomacrophages in the liver, assay of serum and hepatic cytokines, and Th1/Th2 cytokine polarisation were investigated. Immune cell counts indicated overall immunosuppression with decreasing total WBC and splenocyte counts while neutrophil/lymphocyte ratio increased with metal exposure, indicating metal mediated stress. Serum IL6 levels of metal exposed frogs reported the highest (~ 9360 pg/mL) of all cytokines tested. Significantly elevated IFNγ production (P < 0.05) was evident in heavy metal exposed frogs. Th1/Th2 cytokine ratio in both serum and liver tissue homogenates was Th1 skewed due to significantly higher production of pro-inflammatory cytokines, IFNγ in serum and TNFα in the liver (P < 0.01).Metal mediated aggregations of melanomacrophages in the liver were positively and significantly (P < 0.05) correlated with the hepatic expression of TNFα, IL6 and IL10 activity. Overall, Th1 skewed response may well be due to oxidative stress mediated nuclear factor κ-light chain enhancer of activated B cells (NFκB) which enhances the transcription of pro-inflammatory cytokines. Xenobiotic stress has recently imposed an unprecedented level of threat to wildlife, particularly to sensitive species such as amphibians. Therefore, understanding the interactions between physiological stress and related immune responses is fundamental to conserve these environmental sentinels in the face of emerging eco

  15. Correlational indicators of psychosocial adjustment among senior ...

    African Journals Online (AJOL)

    There was a significant joint contribution of the independent variables (sense of coherence, optimism and self-efficacy) to the prediction of psychosocial adjustment. This suggested that the three independent variables combined accounted for 30.4% (Adj.R2= .304) variation in the prediction of psychosocial adjustment.

  16. Parenting Styles and Adjustment in Gifted Children

    Science.gov (United States)

    Pilarinos, Vassiliki; Solomon, C. R.

    2017-01-01

    The present study examined the relationship between parenting styles and the psychosocial adjustment of 48 children aged 7 to 11 years, each of whom had been identified as gifted on the basis of a score of 130 or above on the Wechsler Intelligence Scale for Children--Fourth Edition. Parenting styles and child psychosocial adjustment were measured…

  17. 14 CFR Appendix - Example of SIFL Adjustment

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Example of SIFL Adjustment Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) POLICY STATEMENTS... taxes for rate purposes. Pt. 399, Subpt. C, Example Example of SIFL Adjustment [Methodology for...

  18. relationship between parenting styles and marital adjustment

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    positive and significant joint relationship between the parenting styles and marital adjustment of married ... correlate significantly with marital adjustment of married teachers in secondary ... In other words, it refers to the management of ... dealing with each other so as to reduce ill-feeling. ..... Behavior exchange in happy.

  19. Psychologica and social adjustment to blindness: Understanding ...

    African Journals Online (AJOL)

    Psychologica and social adjustment to blindness: Understanding from two groups of blind people in Ilorin, Nigeria. ... Background: Blindness can cause psychosocial distress leading to maladjustment if not mitigated. Maladjustment is a secondary burden that further reduces quality of life of the blind. Adjustment is often ...

  20. 28 CFR 11.7 - Salary adjustments.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Salary adjustments. 11.7 Section 11.7 Judicial Administration DEPARTMENT OF JUSTICE DEBT COLLECTION Administration of Debt Collection § 11.7 Salary adjustments. The following debts shall not be subject to the salary offset procedures of § 11.8...

  1. Sickness presence, sick leave and adjustment latitude

    Directory of Open Access Journals (Sweden)

    Joachim Gerich

    2014-10-01

    Full Text Available Objectives: Previous research on the association between adjustment latitude (defined as the opportunity to adjust work efforts in case of illness and sickness absence and sickness presence has produced inconsistent results. In particular, low adjustment latitude has been identified as both a risk factor and a deterrent of sick leave. The present study uses an alternative analytical strategy with the aim of joining these results together. Material and Methods: Using a cross-sectional design, a random sample of employees covered by the Upper Austrian Sickness Fund (N = 930 was analyzed. Logistic and ordinary least square (OLS regression models were used to examine the association between adjustment latitude and days of sickness absence, sickness presence, and an estimator for the individual sickness absence and sickness presence propensity. Results: A high level of adjustment latitude was found to be associated with a reduced number of days of sickness absence and sickness presence, but an elevated propensity for sickness absence. Conclusions: Employees with high adjustment latitude experience fewer days of health complaints associated with lower rates of sick leave and sickness presence compared to those with low adjustment latitude. In case of illness, however, high adjustment latitude is associated with a higher pro­bability of taking sick leave rather than sickness presence.

  2. 7 CFR 718.110 - Adjustments.

    Science.gov (United States)

    2010-01-01

    ... MARKETING QUOTAS, ACREAGE ALLOTMENTS, AND PRODUCTION ADJUSTMENT PROVISIONS APPLICABLE TO MULTIPLE PROGRAMS... in order to avoid a marketing quota penalty if such person: (1) Notifies the county committee of such... committee; and (2) Pays the cost of a farm inspection to determine the adjusted acreage prior to the date...

  3. Does Fall History Influence Residential Adjustments?

    Science.gov (United States)

    Leland, Natalie; Porell, Frank; Murphy, Susan L.

    2011-01-01

    Purpose of the study: To determine whether reported falls at baseline are associated with an older adult's decision to make a residential adjustment (RA) and the type of adjustment made in the subsequent 2 years. Design and Methods: Observations (n = 25,036) were from the Health and Retirement Study, a nationally representative sample of…

  4. 10 CFR 905.34 - Adjustment provisions.

    Science.gov (United States)

    2010-01-01

    ... continue to take place based on existing contract/marketing criteria principles. ... 10 Energy 4 2010-01-01 2010-01-01 false Adjustment provisions. 905.34 Section 905.34 Energy DEPARTMENT OF ENERGY ENERGY PLANNING AND MANAGEMENT PROGRAM Power Marketing Initiative § 905.34 Adjustment...

  5. relationship between parenting styles and marital adjustment

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    The relationship between permissive parenting style and marital adjustment was also very low, positive and insignificant. There was a low, positive and significant joint relationship between the parenting styles and marital adjustment of married teachers in secondary schools in Obio/Akpor Local Government Area of Rivers ...

  6. Equity Mispricing and Leverage Adjustment Costs

    NARCIS (Netherlands)

    Warr, R.S.; Elliott, W.B.; Koeter-Kant, J.; Oztekin, O.

    2012-01-01

    We find that equity mispricing impacts the speed at which firms adjust to their target leverage (TL) and does so in predictable ways depending on whether the firm is over- or underlevered. For example, firms that are above their TL and should therefore issue equity (or retire debt) adjust more

  7. Consanguineous Marriage and Marital Adjustment in Turkey.

    Science.gov (United States)

    Fisiloglu, Hurol

    2001-01-01

    Investigates the relationship between consanguineous marriage and marital adjustment in Turkey. The results of the study show that the consanguineous marriage group had significantly lower marital adjustment and had more conflict with extended family than the nonconsanguineous marriage group. The finding is discussed in the context of research and…

  8. Religiousity, Spirituality and Adolescents' Self-Adjustment

    Science.gov (United States)

    Japar, Muhammad; Purwati

    2014-01-01

    Religiuosity, spirituality, and adolescents' self-adjustment. The objective of this study is to test the correlation among religiosity, spirituality and adolescents' self-adjustment. A quantitative approach was employed in this study. Data were collected from 476 junior high schools students of 13 State Junior High Schools and one Junior High…

  9. Adjustment Following Disability: Representative Case Studies.

    Science.gov (United States)

    Heinemann, Allen W.; Shontz, Franklin C.

    1984-01-01

    Examined adjustment following physical disability using the representative case method with two persons with quadriplegia. Results highlighted the importance of previously established coping styles as well as the role of the environment in adjustment. Willingness to mourn aided in later growth. (JAC)

  10. Adjustment of the Internal Tax Scale

    CERN Multimedia

    2013-01-01

    In application of Article R V 2.03 of the Staff Regulations, the internal tax scale has been adjusted with effect on 1 January 2012. The new scale may be consulted via the CERN Admin e-guide.  The notification of internal annual tax certificate for the financial year 2012 takes into account this adjustment. HR Department (Tel. 73907)

  11. Adjustable Speed Drives - Future Challenges and Applications

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Thoegersen, Paul

    2004-01-01

    The main trends within Adjustable Drives in industrial and appliance applications for the next decade are discussed based on the newest developments seen on the market and a few historical trends. Different drive configurations are presented and the general demands to adjustable speed drives...

  12. CD16+ monocytes and skewed macrophage polarization toward M2 type hallmark heart transplant acute cellular rejection

    NARCIS (Netherlands)

    T.P.P. van den Bosch (Thierry); K. Caliskan (Kadir); M.D. Kraaij (Marina); A.A. Constantinescu (Alina); O.C. Manintveld (Olivier); P.J. Leenen (Pieter); J. von der Thusen (Jan); M.C. Clahsen-van Groningen (Marian); C.C. Baan (Carla); A.T. Rowshani (Ajda)

    2017-01-01

    textabstractBackground: During acute heart transplant rejection, infiltration of lymphocytes and monocytes is followed by endothelial injury and eventually myocardial fibrosis. To date, no information is available on monocyte-macrophage-related cellular shifts and their polarization status during

  13. Cultural Distance Asymmetry in Expatriate Adjustment

    DEFF Research Database (Denmark)

    Selmer, Jan; Chiu, Randy K.; Shenkar, Oded

    2007-01-01

    of the assignment. Design/methodology/approach - Using a two-flow sample of US expatriates in Germany and German expatriates in the USA, we examine and compare the psychological and socio-cultural adjustment of each group of executives. Findings - Controlling for the length of assignment, we find that German...... expatriates in the USA were better adjusted, both socio-culturally and psychologically, than American expatriates in Germany. These results support the asymmetry hypothesis and call into question previous findings attesting to the relationship between CD and expatriate adjustment. Originality......Purpose - The current literature implicitly assumes a symmetric impact of cultural distance (CD) on expatriate adjustment. By using distance as a predictor of adjustment, the literature has rendered the direction of the flow irrelevant: a US expatriate in Germany is presumed to face the same hurdle...

  14. Premorbid adjustment and neuropsychological performance in schizophrenia.

    Science.gov (United States)

    Silverstein, Marshall L; Mavrolefteros, George; Close, David

    2002-01-01

    To examine the relationship between premorbid adjustment and neuropsychological deficit in schizophrenia, this report examined retrospective ratings of social and school adjustment during three age epochs (childhood, early adolescence, and late adolescence) as predictors of neurocognitive performance in 61 clinically and pharmacologically stabilized schizophrenia outpatients. Results indicated greater cognitive deficits when premorbid adjustment was unfavorable, particularly for measures of attention and executive functions. Premorbid number and quality of peer relationships and psychosocial adaptation to the school environment were more closely related to neuropsychological performance during adulthood than were premorbid withdrawal and premorbid academic performance. Early onset of poor premorbid adjustment rather than deterioration from childhood to adolescence was associated with greater neuropsychological disturbance in adulthood. It is suggested that childhood onset of premorbid deficits in selective areas of social and academic adjustment appears to influence the cognitive performance seen in adult schizophrenia. This study is consistent with findings from other related reports; it extends these findings to a larger and clinically stabilized sample.

  15. Skewed Helper T-Cell Responses to IL-12 Family Cytokines Produced by Antigen-Presenting Cells and the Genetic Background in Behcet’s Disease

    Directory of Open Access Journals (Sweden)

    Jun Shimizu

    2013-01-01

    Full Text Available Behcet’s disease (BD is a multisystemic inflammatory disease and is characterized by recurrent attacks on eyes, brain, skin, and gut. There is evidence that skewed T-cell responses contributed to its pathophysiology in patients with BD. Recently, we found that Th17 cells, a new helper T (Th cell subset, were increased in patients with BD, and both Th type 1 (Th1 and Th17 cell differentiation signaling pathways were overactivated. Several researches revealed that genetic polymorphisms in Th1/Th17 cell differentiation signaling pathways were associated with the onset of BD. Here, we summarize current findings on the Th cell subsets, their contribution to the pathogenesis of BD and the genetic backgrounds, especially in view of IL-12 family cytokine production and pattern recognition receptors of macrophages/monocytes.

  16. Experimental and Simulation-Based Investigation of Polycentric Motion of an Inherent Compliant Pneumatic Bending Actuator with Skewed Rotary Elastic Chambers

    Directory of Open Access Journals (Sweden)

    André Wilkening

    2017-01-01

    Full Text Available To offer a functionality that could not be found in traditional rigid robots, compliant actuators are in development worldwide for a variety of applications and especially for human–robot interaction. Pneumatic bending actuators are a special kind of such actuators. Due to the absence of fixed mechanical axes and their soft behavior, these actuators generally possess a polycentric motion ability. This can be very useful to provide an implicit self-alignment to human joint axes in exoskeleton-like rehabilitation devices. As a possible realization, a novel bending actuator (BA was developed using patented pneumatic skewed rotary elastic chambers (sREC. To analyze the actuator self-alignment properties, knowledge about the motion of this bending actuator type, the so-called skewed rotary elastic chambers bending actuator (sRECBA, is of high interest and this paper presents experimental and simulation-based kinematic investigations. First, to describe actuator motion, the finite helical axes (FHA of basic actuator elements are determined using a three-dimensional (3D camera system. Afterwards, a simplified two-dimensional (2D kinematic simulation model based on a four-bar linkage was developed and the motion was compared to the experimental data by calculating the instantaneous center of rotation (ICR. The equivalent kinematic model of the sRECBA was realized using a series of four-bar linkages and the resulting ICR was analyzed in simulation. Finally, the FHA of the sRECBA were determined and analyzed for three different specific motions. The results show that the actuator’s FHA adapt to different motions performed and it can be assumed that implicit self-alignment to the polycentric motion of the human joint axis will be provided.

  17. Case-mix adjustment for diabetes indicators: a systematic review.

    Science.gov (United States)

    Calsbeek, Hiske; Markhorst, Joekle G M; Voerman, Gerlienke E; Braspenning, Jozé C C

    2016-02-01

    Case-mix adjustment is generally considered indispensable for fair comparison of healthcare performance. Inaccurate results are also unfair to patients as they are ineffective for improving quality. However, little is known about what factors should be adjusted for. We reviewed case-mix factors included in adjustment models for key diabetes indicators, the rationale for their inclusion, and their impact on performance. Systematic review. This systematic review included studies published up to June 2013 addressing case-mix factors for 6 key diabetes indicators: 2 outcomes and 2 process indicators for glycated hemoglobin (A1C), low-density lipoprotein cholesterol, and blood pressure. Factors were categorized as demographic, diabetes-related, comorbidity, generic health, geographic, or care-seeking, and were evaluated on the rationale for inclusion in the adjustment models, as well as their impact on indicator scores and ranking. Thirteen studies were included, mainly addressing A1C value and measurement. Twenty-three different case-mix factors, mostly demographic and diabetes-related, were identified, and varied from 1 to 14 per adjustment model. Six studies provided selection motives for the inclusion of case-mix factors. Marital status and body mass index showed a significant impact on A1C value. For the other factors, either no or conflicting associations were reported, or too few studies (n ≤ 2) investigated this association. Scientific knowledge about the relative importance of case-mix factors for diabetes indicators is emerging, especially for demographic and diabetes-related factors and indicators on A1C, but is still limited. Because arbitrary adjustment potentially results in inaccurate quality information, meaningful stratification that demonstrates inequity in care might be a better guide, as it can be a driver for quality improvement.

  18. Child, Parent and Family Factors as Predictors of Adjustment for Siblings of Children with a Disability

    Science.gov (United States)

    Giallo, R.; Gavidia-Payne, S.

    2006-01-01

    Background: Siblings adjust to having a brother or sister with a disability in diverse ways. This study investigated a range of child, parent and family factors as predictors of sibling adjustment outcomes. Methods: Forty-nine siblings (aged 7-16 years) and parents provided information about (1) sibling daily hassles and uplifts; (2) sibling…

  19. Adjustment in property space markets: taking long-term leases and transaction costs seriously

    NARCIS (Netherlands)

    Englund, P.; Gunnelin, Å.; Hendershott, P.H.; Söderberg, B.

    2008-01-01

    Markets for property space adjust only gradually because tenants and landlords are constrained by long-term leases and transaction and information costs. Not only do rents adjust slowly, but space occupancy, which depends on historical rents, often differs from demand at current rent. This creates

  20. Role of Osmotic Adjustment in Plant Productivity

    Energy Technology Data Exchange (ETDEWEB)

    Gebre, G.M.

    2001-01-11

    Successful implementation of short rotation woody crops requires that the selected species and clones be productive, drought tolerant, and pest resistant. Since water is one of the major limiting factors in poplar (Populus sp.) growth, there is little debate for the need of drought tolerant clones, except on the wettest of sites (e.g., lower Columbia River delta). Whether drought tolerance is compatible with productivity remains a debatable issue. Among the many mechanisms of drought tolerance, dehydration postponement involves the maintenance of high leaf water potential due to, for example, an adequate root system. This trait is compatible with productivity, but requires available soil moisture. When the plant leaf water potential and soil water content decline, the plant must be able to survive drought through dehydration tolerance mechanisms, such as low osmotic potential or osmotic adjustment. Osmotic adjustment and low osmotic potential are considered compatible with growth and yield because they aid in the maintenance of leaf turgor. However, it has been shown that turgor alone does not regulate cell expansion or stomatal conductance and, therefore, the role of osmotic adjustment is debated. Despite this finding, osmotic adjustment has been correlated with grain yield in agronomic crop species, and gene markers responsible for osmotic adjustment are being investigated to improve drought tolerance in productive progenies. Although osmotic adjustment and low osmotic potentials have been investigated in several forest tree species, few studies have investigated the relationship between osmotic adjustment and growth. Most of these studies have been limited to greenhouse or container-grown plants. Osmotic adjustment and rapid growth have been specifically associated in Populus and black spruce (Picea mariuna (Mill.) B.S.P.) progenies. We tested whether these relationships held under field conditions using several poplar clones. In a study of two hybrid poplar

  1. Adjustment and mental health problem in prisoners

    Directory of Open Access Journals (Sweden)

    Sudhinta Sinha

    2010-01-01

    Full Text Available Background : "Crime" is increasing day by day in our society not only in India but also all over the world. In turn, the number of prisoners is also increasing at the same rate. They remain imprisoned for a long duration or in some cases for the whole life. Living in a prison for long time becomes difficult for all inmates. So they often face adjustment and mental health problems. Recent findings suggest that mental illness rate in prison is three times higher than in the general population. Objective: The aim of the present study was to investigate the adjustment and the mental health problem and its relation in the prisoners. Materials and Methods : In the present study, 37 male prisoners of district jail of Dhanbad District of Jharkhand were selected on purposive sampling basis. Each prisoner was given specially designed Performa - Personal Data Sheet, General Health Questionnaire-12 and Bell Adjustment Inventory. Appropriate statistical tools were used to analyze the data. Results: The results obtained showed poor adjustment in social and emotional areas on the adjustment scale. The study also revealed a significant association between adjustment and mental health problem in the prisoners. Conclusion: The prisoners were found to have poor social and emotional adjustment which has strong association with their mental health.

  2. 39 CFR 3010.25 - Limitation on unused rate adjustment authority rate adjustments.

    Science.gov (United States)

    2010-07-01

    ... only be applied together with inflation-based limitation rate adjustments or when inflation-based... used in lieu of an inflation-based limitation rate adjustment. ... 39 Postal Service 1 2010-07-01 2010-07-01 false Limitation on unused rate adjustment authority...

  3. Revenge and psychological adjustment after homicidal loss.

    Science.gov (United States)

    van Denderen, Mariëtte; de Keijser, Jos; Gerlsma, Coby; Huisman, Mark; Boelen, Paul A

    2014-01-01

    Feelings of revenge are a common human response to being hurt by others. Among crime victims of severe sexual or physical violence, significant correlations have been reported between revenge and Posttraumatic Stress Disorder (PTSD). Homicide is one of the most severe forms of interpersonal violence. It is therefore likely that individuals bereaved by homicide experience high levels of revenge, which may hamper efforts to cope with traumatic loss. The relationship between revenge and psychological adjustment following homicidal loss has not yet been empirically examined. In the current cross-sectional study, we used self-report data from 331 spouses, family members and friends of homicide victims to examine the relationships between dispositional revenge and situational revenge on the one hand and symptom-levels of PTSD and complicated grief, as well as indices of positive functioning, on the other hand. Furthermore, the association between revenge and socio-demographic and offense-related factors was examined. Participants were recruited from a governmental support organization, a website with information for homicidally bereaved individuals, and members of support groups. Levels of both dispositional and situational revenge were positively associated with symptoms of PTSD and complicated grief, and negatively with positive functioning. Participants reported significantly less situational revenge in cases where the perpetrator was a direct family member than cases where the perpetrator was an indirect family member, friend, or someone unknown. Homicidally bereaved individuals reported more situational revenge, but not more dispositional revenge than a sample of students who had experienced relatively mild interpersonal transgressions. © 2014 Wiley Periodicals, Inc.

  4. [Psychosocial adjustment in colorectal cancer patients undergoing chemotherapy or chemoradiotherapy].

    Science.gov (United States)

    Alvarado-Aguilar, Salvador; Guerra-Cruz, Hilda Griselda; Cupil-Rodríguez, Aura Lizbet; Calderillo-Ruiz, Germán; Oñate-Ocaña, Luis Fernando

    2011-01-01

    Psychosocial adaptation is a measurement that represents the patient's adjustment to those changes involved in their illness. We undertook this study to search for individual characteristics and clinical aspects associated with successful psychosocial adjustment in patients with colorectal cancer (CRC) undergoing (CT) chemotherapy or chemoradiotherapy (CRT). Seventy-five patients with CRC treated with CT or CRT in a cancer center were included. Psychosocial Adjustment to Illness Scale Self-Reporting (PAIS-SR) questionnaire was used as a measurement of psychosocial adjustment. Psychosocial adaptation was successful in 18 patients (24%) and unsuccessful in 57 patients (76%). Young patients, married patients and males showed lower psychosocial adaptation to disease. This is associated with the decrease in sexual relations, economic resources and psychological symptoms. Patients complained that they were unsatisfied due to the lack of disease and treatment information offered by the heath care team. In the process of adaptation, clinical features such as tumor location and treatment scheme are considered basic, as well as age, education, marital status. Areas such as sexuality, interpersonal and family relationships, economic status and emotional state of patients affected by the disease and treatments provide a deep complexity in the study of the psychosocial adaptation process in patients with CRC.

  5. Adjustment to Cancer: Anxiety and Distress (PDQ)

    Science.gov (United States)

    ... with adjustment disorders. Individual (one-to-one) and group counseling have been shown to help cancer patients with ... to-one) counseling. Couple and family counseling. Crisis counseling. Group therapy. Self-help groups. Other treatments used to ...

  6. Adjusting water resources management to climate change

    Energy Technology Data Exchange (ETDEWEB)

    Riebsame, W E

    1988-01-01

    The nature of climate impacts and adjustment in water supply and flood management is discussed, and a case study of water manager response to climate fluctuation in California's Sacramento Basin is presented. The case illuminates the effect on climate impact and response of traditional management approaches, the dynamic qualities of maturing water systems, socially imposed constraints, and climate extremes. A dual pattern of crisis-response and gradual adjustment emerges, and specific mechanisms for effecting adjustment of water management systems are identified. The case study, and broader trends in US water development, suggest that oversized structural capacity, the traditional adjustment to climate variability in water resources, may prove less feasible in the future as projects become smaller and new facilities are delayed by economic and environmental concerns.

  7. Theatre Practice and Social Adjustment in Nigeria

    African Journals Online (AJOL)

    Nneka Umera-Okeke

    Media Sociology Lecturer ... adjustments in favour of local processes to drive social and economic .... needs the need to meet the requirements of all motivated efficiency, a certain degree of .... Centre for Production of Tourism, Arts and Culture.

  8. Annual adjustments to 2015 financial benefits

    CERN Multimedia

    HR Department

    2015-01-01

    In accordance with recommendations made by the Finance Committee and decisions taken by Council in December 2014, no adjustments have been made to basic salaries and stipends, subsistence allowances or family benefits as at 1 January 2015.

  9. Annual adjustments to 2016 financial benefits

    CERN Multimedia

    HR Department

    2016-01-01

    In accordance with recommendations made by the Finance Committee and decisions taken by the Council in December 2015, no adjustments have been made to basic salaries and stipends, subsistence allowances or family benefits as at 1 January 2016.  

  10. Annual adjustments to 2014 financial benefits

    CERN Multimedia

    2013-01-01

    In accordance with recommendations made by the Finance Committee and decisions taken by Council in December 2013, no adjustments have been made to basic salaries and stipends, subsistence allowances or family benefits as at 1 January 2014. HR Department

  11. Marital Adjustment and Psychological Distress in Japan

    Science.gov (United States)

    Li, Angela; Robustelli, Briana L.; Whisman, Mark A.

    2016-01-01

    This study was conducted to examine the association between marital adjustment and psychological distress in a large, probability sample of married adults in Japan (N = 710) from the Midlife Development in Japan (MIDJA) study. Results indicate that positive and negative dimensions of marital adjustment were significantly associated with dimensional and categorical measures of psychological distress. Furthermore, the associations between marital adjustment and psychological distress remained significant when statistically controlling for neuroticism, quality of friend and family relationships, and demographic variables. These results demonstrate that the well-established association between marital adjustment and psychological distress found in European-American countries is also found in Japan. Findings support continued research on marital functioning and psychological distress in East Asian countries. PMID:28082761

  12. Speed of adjustment: Evidence from Borsa Istanbul

    Directory of Open Access Journals (Sweden)

    Emrah Arioglu

    2014-06-01

    Full Text Available In this study, we investigate the speed of adjustment for leverage ratios of firms listed on Borsa Istanbul, in order to investigate the prediction of the trade-off theory, regarding capital structure rebalancing. For this purpose, we estimate the speed of adjustment by using Generalized Method of Moments system estimation technique. The results of this estimation suggest the speed of adjustment as approximately 29%. This significant speed of adjustment is consistent with the prediction of trade-off theory, which suggests that firms follow target capital structures and when the firms' leverage ratios deviate from these targets; they make financial decisions with the goal of closing the gap between the previous year's leverage and target leverage of the current period.

  13. Annual adjustments to 2013 financial benefits

    CERN Multimedia

    2013-01-01

    In accordance with recommendations made by the Finance Committee and decisions taken by Council in December 2012, no adjustments have been made to basic salaries and stipends, subsistence allowances or family benefits as at 1 January 2013. HR Department

  14. Determinants of intercultural adjustment among expatriate spouses

    NARCIS (Netherlands)

    Ali, Anees; Van der Zee, K.I.; Sanders, G

    The adaptation of expatriate families to a host country seems crucial to successful fulfilment of international business assignments. The present study focused on personality, family characteristics and characteristics of expatriates' work life as determinants of the intercultural adjustment of

  15. Price Changes, Resource Adjustments and Rational Expectations

    DEFF Research Database (Denmark)

    Hoffmann, Kira

    This study investigates the relationship between the accuracy of managerial demand expectations, resource adjustment decisions and selling price changes. In line with rational expectation theory, it is argued that managers adjust resources and selling prices differently in response to expected...... that cost elasticity is higher when a demand decrease is expected among companies with similar exposure to demand uncertainty. Overall, this implies that managerial competences in predicting future demand significantly determines firms’ profitability; especially when demand uncertainty is high...

  16. CD16+ Monocytes and Skewed Macrophage Polarization toward M2 Type Hallmark Heart Transplant Acute Cellular Rejection

    OpenAIRE

    van den Bosch, Thierry P. P.; Caliskan, Kadir; Kraaij, Marina D.; Constantinescu, Alina A.; Manintveld, Olivier C.; Leenen, Pieter J. M.; von der Th?sen, Jan H.; Clahsen-van Groningen, Marian C.; Baan, Carla C.; Rowshani, Ajda T.

    2017-01-01

    textabstractBackground: During acute heart transplant rejection, infiltration of lymphocytes and monocytes is followed by endothelial injury and eventually myocardial fibrosis. To date, no information is available on monocyte-macrophage-related cellular shifts and their polarization status during rejection. Here, we aimed to define and correlate monocyte-macrophage endomyocardial tissue profiles obtained at rejection and time points prior to rejection, with corresponding serial blood samples ...

  17. Adolescents conceived by IVF: parenting and psychosocial adjustment.

    Science.gov (United States)

    Colpin, H; Bossaert, G

    2008-12-01

    A follow-up study was conducted in mid-adolescence on parenting and the child's psychosocial development after in vitro fertilization (IVF). The first phase of the study had compared 31 IVF families and 31 families with a naturally conceived child when the children were 2 years old (Colpin et al., 1995). Of these, 24 IVF families and 21 control families participated again when the children were 15-16 years old. Fathers, mothers and adolescents completed questionnaires assessing parenting style and stress, and adolescent psychosocial adjustment. No significant differences were found in self- or adolescent-reported parenting style, or in parenting stress between IVF mothers and mothers in the control group, nor between IVF fathers and fathers in the control group. Neither did we find significant differences in self- or parent-reported behavioural problems between adolescents conceived by IVF and those conceived naturally. Comparison of behavioural problems between IVF adolescents informed or not informed about the IVF conception did not reveal significant differences. Parenting and 15-16-year-old adolescents' psychosocial adjustment did not differ significantly between IVF families and control families. This study is, to the best of our knowledge, the first psychosocial follow-up in mid-adolescence, and adds to the evidence that IVF children and their parents are well-adjusted. Large-scale studies in adolescence are needed to support these findings.

  18. Nuclear data adjustment methodology utilizing resonance parameter sensitivities and uncertainties

    International Nuclear Information System (INIS)

    Broadhead, B.L.

    1983-01-01

    This work presents the development and demonstration of a Nuclear Data Adjustment Method that allows inclusion of both energy and spatial self-shielding into the adjustment procedure. The resulting adjustments are for the basic parameters (i.e. resonance parameters) in the resonance regions and for the group cross sections elsewhere. The majority of this development effort concerns the production of resonance parameter sensitivity information which allows the linkage between the responses of interest and the basic parameters. The resonance parameter sensitivity methodology developed herein usually provides accurate results when compared to direct recalculations using existng and well-known cross section processing codes. However, it has been shown in several cases that self-shielded cross sections can be very non-linear functions of the basic parameters. For this reason caution must be used in any study which assumes that a linear relatonship exists between a given self-shielded group cross section and its corresponding basic data parameters. The study also has pointed out the need for more approximate techniques which will allow the required sensitivity information to be obtained in a more cost effective manner

  19. Topics in data adjustment theory and applications

    International Nuclear Information System (INIS)

    Hwang, R.N.

    1988-01-01

    The methodologies of the uncertainty analysis and data adjustment have been well-developed and widely used abroad since the early 70's. With limited amount of covariance data on the differential cross section and the integral experiments available at the time, their accomplishments are, indeed, astounding. The fundamental adjustment equations, however, remain qualitatively unchanged. For the past few year, extensive efforts on these subjects have also begun at ANL in order to utilize the massive amount of integral experiments accumulated over years to provide the basis for improving the reactor parameters encountered in various design calculations. Pertinent covariance matrices and sensitivity matrices of the existing integral experiments have been evaluated and systematically compiled in the data files along with the cross section covariance data derived from the ENDF-B/V for the 21 group structure currently under consideration. A production code GMADJ that provides the adjusted quantities for a large number of cross section types has been developed by Poenitz for routine applications. The primary purpose of the present paper is to improve understanding of the application oriented issues important to the data adjustment theory and the subsequent usage of the adjusted quantities in the design calculations in support of these activities. 30 refs., 12 figs., 5 tabs

  20. Three-part joint modeling methods for complex functional data mixed with zero-and-one-inflated proportions and zero-inflated continuous outcomes with skewness.

    Science.gov (United States)

    Li, Haocheng; Staudenmayer, John; Wang, Tianying; Keadle, Sarah Kozey; Carroll, Raymond J

    2018-02-20

    We take a functional data approach to longitudinal studies with complex bivariate outcomes. This work is motivated by data from a physical activity study that measured 2 responses over time in 5-minute intervals. One response is the proportion of time active in each interval, a continuous proportions with excess zeros and ones. The other response, energy expenditure rate in the interval, is a continuous variable with excess zeros and skewness. This outcome is complex because there are 3 possible activity patterns in each interval (inactive, partially active, and completely active), and those patterns, which are observed, induce both nonrandom and random associations between the responses. More specifically, the inactive pattern requires a zero value in both the proportion for active behavior and the energy expenditure rate; a partially active pattern means that the proportion of activity is strictly between zero and one and that the energy expenditure rate is greater than zero and likely to be moderate, and the completely active pattern means that the proportion of activity is exactly one, and the energy expenditure rate is greater than zero and likely to be higher. To address these challenges, we propose a 3-part functional data joint modeling approach. The first part is a continuation-ratio model to reorder the ordinal valued 3 activity patterns. The second part models the proportions when they are in interval (0,1). The last component specifies the skewed continuous energy expenditure rate with Box-Cox transformations when they are greater than zero. In this 3-part model, the regression structures are specified as smooth curves measured at various time points with random effects that have a correlation structure. The smoothed random curves for each variable are summarized using a few important principal components, and the association of the 3 longitudinal components is modeled through the association of the principal component scores. The difficulties in