Baker, Emily; Hunter, Tiffany; Okun, Nanette; Farine, Dan
2015-05-01
We sought to determine the interventions utilized by maternal-fetal medicine specialists in the prediction and prevention of preterm labor in higher-order multiple (HOM) gestations. Online questionnaires and email surveys were sent to all the maternal-fetal medicine specialists in Canada (n=122). Questionnaire items included interventions physicians routinely recommended for HOM gestations including: (1) bed rest; (2) cervical length measurement on transvaginal ultrasound; (3) corticosteroids use; (4) cerclage; and (5) tocolytic therapy. Response rate was 66% (81/122), with 68% of respondents in practice for >10 years. Of physicians, 91% did not routinely recommend bed rest (95% confidence interval [CI], 84.7-97.2). In all, 82% (95% CI, 73.63-90.4%) recommended routine cervical length assessment with 32.3% (95% CI, 20.7-43.2) and 37.1% (95% CI, 25.3-48.6) of this group suggesting assessment at 16-18 and 19-21 weeks, respectively. Frequency of assessment varied from biweekly (53.3%; 95% CI, 40.9-65.0), to monthly (23.3%; 95% CI, 12.8-33.1), to a single measurement repeated only if abnormal (12.5%; 95% CI, 4.5-20.8). In all, 28% (95% CI, 18.2-37.8) recommended routine administration of corticosteroids for lung maturation. Timing of administration varied, with 24% initiating steroids between 24-26 weeks, 59% between 27-28 weeks, and 17% after 28 weeks. None reported routine cerclage placement. However, 71% (95% CI, 61.1-80.8) would perform cerclage based on history or ultrasound. Of respondents, 81% (95% CI, 72.4-89.5) would consider using tocolytic agents for threatened preterm labor including calcium channel blockers (94%), nonsteroidal antiinflammatory drugs (5%), and nitroglycerin transdermal patch (24%). The variable practice guidelines and paucity of data for management of HOM pregnancy places the onus on individual practitioners to develop their own management schemes. This results in heterogeneous management, which is based on conflicting international
Predictors of third and Higher order births in India
Directory of Open Access Journals (Sweden)
Payal Singh
2015-12-01
Full Text Available Background: Total fertility rate (TFR reflecting population growth is closely related to higher order parity progression. Many Indian states reached replacement level of TFR, but still states constituting nearly 40% population are with TFR ≥ 3. The predictors are the desire of son’s, poor contraceptives practices, younger age at marriage, child loss and shorter birth spacing. Objective: This analysis assessed the degree of relation of 3rd and higher order parity progression with the above mentioned predictors. Material and Methods: State/Union Territories wise proportions of women: progressing to ≥3 births, more sons desire, birth spacing <24 months, adopting modern contraception and median marriage age <18 years along with infant mortality rate (IMR were taken from NFHS-III report. Correlation matrix and stepwise forward multiple regression carried. Significance was seen at 5%. Results: Hindi speaking states constituting 38.92% nation population recorded TFR ≥3. Positive correlation of mothers progressing ≥ 3 births was highest (0.746 with those desiring more sons followed by IMR (0.445; while maximum negative correlation with those practicing modern contraceptives (-0.565 followed by median age at marriage (-0.391. Multiple regression analysis in order identified desire of more sons, practicing modern contraception and shorter birth spacing as the significant predictors and jointly explained 77.9% of the total variation with gain of 15.5% by adding modern contraceptive practice and 8.3% by adding shorter birth spacing. Conclusions: Desire of more sons appeared the most important predictor to progress ≥3 births that is governed by society culture and educational attainment, require attitudinal change. Further, mothers need motivation to practice both spacing and terminal methods once family is complete.
Neurodevelopmental outcomes of triplets or higher-order extremely low birth weight infants.
Wadhawan, Rajan; Oh, William; Vohr, Betty R; Wrage, Lisa; Das, Abhik; Bell, Edward F; Laptook, Abbot R; Shankaran, Seetha; Stoll, Barbara J; Walsh, Michele C; Higgins, Rosemary D
2011-03-01
Extremely low birth weight twins have a higher rate of death or neurodevelopmental impairment than singletons. Higher-order extremely low birth weight multiple births may have an even higher rate of death or neurodevelopmental impairment. Extremely low birth weight (birth weight 401-1000 g) multiple births born in participating centers of the Neonatal Research Network between 1996 and 2005 were assessed for death or neurodevelopmental impairment at 18 to 22 months' corrected age. Neurodevelopmental impairment was defined by the presence of 1 or more of the following: moderate to severe cerebral palsy; mental developmental index score or psychomotor developmental index score less than 70; severe bilateral deafness; or blindness. Infants who died within 12 hours of birth were excluded. Maternal and infant demographic and clinical variables were compared among singleton, twin, and triplet or higher-order infants. Logistic regression analysis was performed to establish the association between singletons, twins, and triplet or higher-order multiples and death or neurodevelopmental impairment, controlling for confounding variables that may affect death or neurodevelopmental impairment. Our cohort consisted of 8296 singleton, 2164 twin, and 521 triplet or higher-order infants. The risk of death or neurodevelopmental impairment was increased in triplets or higher-order multiples when compared with singletons (adjusted odds ratio: 1.7 [95% confidence interval: 1.29-2.24]), and there was a trend toward an increased risk when compared with twins (adjusted odds ratio: 1.27 [95% confidence: 0.95-1.71]). Triplet or higher-order births are associated with an increased risk of death or neurodevelopmental impairment at 18 to 22 months' corrected age when compared with extremely low birth weight singleton infants, and there was a trend toward an increased risk when compared with twins.
Higher order multiple pregnancy outcomes in the Maltese islands 2000-2004
Savona-Ventura, Charles; Gatt, Miriam; Vella, Katya; Grima, Stephen
2008-01-01
Higher order multiple births have increased significantly in the last decades throughout the developed world. In spite of advances in obstetric care seen throughout the second half of the twentieth century, the perinatal outcomes associated with a multiple pregnancy remain associated with increased morbidity and mortality for the mother and the infants. This study attempts to assess the characteristics and outcomes of these maternities in the Maltese population. The National maternity data fo...
Childhood cancer among twins and higher order multiples
Puumala, Susan E.; Carozza, Susan E.; Chow, Eric J.; Fox, Erin E.; Horel, Scott; Johnson, Kimberly J.; McLaughlin, Colleen; Mueller, Beth A.; Reynolds, Peggy; Von Behren, Julie; Spector, Logan G.
2009-01-01
Although several studies have found no change or a decreased risk of childhood cancer in twins, few have controlled for potential confounders such as birth weight. We examined the association of birth plurality and childhood cancer in pooled data from five U.S. states (California, Minnesota, New York, Texas, and Washington) using linked birth-cancer registry data. The data, excluding children with Down syndrome or who died before 28 days of life, included 17,672 cases diagnosed 1980–2004 at a...
Average gluon and quark jet multiplicities at higher orders
Energy Technology Data Exchange (ETDEWEB)
Bolzoni, Paolo; Kniehl, Bernd A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Kotikov, Anatoly V. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Joint Institute of Nuclear Research, Moscow (Russian Federation). Bogoliubov Lab. of Theoretical Physics
2013-05-15
We develop a new formalism for computing and including both the perturbative and nonperturbative QCD contributions to the scale evolution of average gluon and quark jet multiplicities. The new method is motivated by recent progress in timelike small-x resummation obtained in the MS factorization scheme. We obtain next-to-next-to-leading-logarithmic (NNLL) resummed expressions, which represent generalizations of previous analytic results. Our expressions depend on two nonperturbative parameters with clear and simple physical interpretations. A global fit of these two quantities to all available experimental data sets that are compatible with regard to the jet algorithms demonstrates by its goodness how our results solve a longstanding problem of QCD. We show that the statistical and theoretical uncertainties both do not exceed 5% for scales above 10 GeV. We finally propose to use the jet multiplicity data as a new way to extract the strong-coupling constant. Including all the available theoretical input within our approach, we obtain {alpha}{sub s}{sup (5)}(M{sub Z})=0.1199{+-}0.0026 in the MS scheme in an approximation equivalent to next-to-next-to-leading order enhanced by the resummations of ln(x) terms through the NNLL level and of ln Q{sup 2} terms by the renormalization group, in excellent agreement with the present world average.
Higher Order Multiple Births in Nigeria: Experiences, Challenges ...
African Journals Online (AJOL)
women in Nigeria,[10] ... of three or more babies in one pregnancy. ... Objectives: The aim of this study is to describe the experience and outcome ... and build upon the work non-commercially, as long as the author is credited and the new ..... trend of women pursuing careers earlier in life and .... Achebe C. Things Fall Apart.
Combining higher-order resummation with multiple NLO calculations and parton showers in GENEVA
Energy Technology Data Exchange (ETDEWEB)
Alioli, Simone; Bauer, Christian W.; Berggren, Calvin; Vermilion, Christopher K.; Walsh, Jonathan R.; Zuberi, Saba [California Univ., Berkeley, CA (United States). Ernest Orlando Lawrence Berkeley National Laboratory; Hornig, Andrew [Washington Univ., Seattle, WA (United States). Dept. of Physics; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie
2012-11-15
We extend the lowest-order matching of tree-level matrix elements with parton showers to give a complete description at the next higher perturbative accuracy in {alpha}{sub s} at both small and large jet resolutions, which has not been achieved so far. This requires the combination of the higher-order resummation of large Sudakov logarithms at small values of the jet resolution variable with the full next-to-leading order (NLO) matrix-element corrections at large values. As a by-product, this combination naturally leads to a smooth connection of the NLO calculations for different jet multiplicities. In this paper, we focus on the general construction of our method and discuss its application to e{sup +}e{sup -} and pp collisions. We present first results of the implementation in the GENEVA Monte Carlo framework. We employ N-jettiness as the jet resolution variable, combining its next-to-next-to-leading logarithmic resummation with fully exclusive NLO matrix elements, and PYTHIA 8 as the backend for further parton showering and hadronization. For hadronic collisions, we take Drell-Yan production as an example to apply our construction. For e{sup +}e{sup -} {yields} jets, taking {alpha}{sub s}(m{sub Z}) = 0.1135 from fits to LEP thrust data, together with the PYTHIA 8 hadronization model, we obtain good agreement with LEP data for a variety of 2-jet observables.
Method of applying single higher order polynomial basis function over multiple domains
CSIR Research Space (South Africa)
Lysko, AA
2010-03-01
Full Text Available A novel method has been devised where one set of higher order polynomial-based basis functions can be applied over several wire segments, thus permitting to decouple the number of unknowns from the number of segments, and so from the geometrical...
Prevention of triplets and higher order multiples: trends in reproductive medicine.
Armour, Kim L; Callister, Lynn Clark
2005-01-01
In the United States and throughout the world, today's healthcare providers are challenged by the risks of multiple gestation pregnancy. Assisted reproductive technologies (ARTs) often used to treat infertility raise ethical issues including informed consent, veracity, and nonmalificence. In the United States, there is the need to improve maternal and fetal/neonatal mortality and morbidity by proposing legislation regulating ART and supporting single embryo transfers with no more than 2 such transfers. Beginning with the diagnosis of infertility, providers have a responsibility to educate, inform, and treat infertile couples. From the moment pregnancy with multiples is confirmed, these families are faced with incredible stressors including decision making on multifetal or selective reduction. Full disclosure of risks involved throughout the course of care should be discussed and documented in the record and plan of care. Currently in the United States, legislation does not regulate ART, including ovulation induction/enhancement and in vitro fertilization. Although the United States does have self-regulation via limited reporting through their professional organization and the Centers for Disease Control and Prevention, an unlimited number of embryos may be transferred. Unfortunately, many healthcare providers have not recognized the responsibility and burden placed on families and society as a whole. Lack of regulation means women may become pregnant with high order multiples, which raises serious moral and ethical issues.
International Nuclear Information System (INIS)
Alioli, Simone; Bauer, Christian W.; Berggren, Calvin; Vermilion, Christopher K.; Walsh, Jonathan R.; Zuberi, Saba; Hornig, Andrew; Tackmann, Frank J.
2013-05-01
We discuss the GENEVA Monte Carlo framework, which combines higher-order resummation (NNLL) of large Sudakov logarithms with multiple next-to-leading-order (NLO) matrix-element corrections and parton showering (using PYTHIA 8) to give a complete description at the next higher perturbative accuracy in α s at both small and large jet resolution scales. Results for e + e - →jets compared to LEP data and pp→(Z/γ * →l + l - )+jets are presented.
Directory of Open Access Journals (Sweden)
Sri Priya Ponnapalli
Full Text Available The number of high-dimensional datasets recording multiple aspects of a single phenomenon is increasing in many areas of science, accompanied by a need for mathematical frameworks that can compare multiple large-scale matrices with different row dimensions. The only such framework to date, the generalized singular value decomposition (GSVD, is limited to two matrices. We mathematically define a higher-order GSVD (HO GSVD for N≥2 matrices D(i∈R(m(i × n, each with full column rank. Each matrix is exactly factored as D(i=U(iΣ(iV(T, where V, identical in all factorizations, is obtained from the eigensystem SV=VΛ of the arithmetic mean S of all pairwise quotients A(iA(j(-1 of the matrices A(i=D(i(TD(i, i≠j. We prove that this decomposition extends to higher orders almost all of the mathematical properties of the GSVD. The matrix S is nondefective with V and Λ real. Its eigenvalues satisfy λ(k≥1. Equality holds if and only if the corresponding eigenvector v(k is a right basis vector of equal significance in all matrices D(i and D(j, that is σ(i,k/σ(j,k=1 for all i and j, and the corresponding left basis vector u(i,k is orthogonal to all other vectors in U(i for all i. The eigenvalues λ(k=1, therefore, define the "common HO GSVD subspace." We illustrate the HO GSVD with a comparison of genome-scale cell-cycle mRNA expression from S. pombe, S. cerevisiae and human. Unlike existing algorithms, a mapping among the genes of these disparate organisms is not required. We find that the approximately common HO GSVD subspace represents the cell-cycle mRNA expression oscillations, which are similar among the datasets. Simultaneous reconstruction in the common subspace, therefore, removes the experimental artifacts, which are dissimilar, from the datasets. In the simultaneous sequence-independent classification of the genes of the three organisms in this common subspace, genes of highly conserved sequences but significantly different cell
Fluellen, Jerry
Howard Gardner and Jerome Bruner have given much to teachers who want to know how the minds of children grow. This story of a girl's construction of higher order, verbal linguistic intelligence is also theirs. Ideas they created have been cloned to fit a big city, public school classroom of African American 4th graders, each with a set of multiple…
Birth Control - Multiple Languages
... Methods - English PDF How to Switch Birth Control Methods - 简体中文 (Chinese, Simplified (Mandarin dialect)) ... Reproductive Health Access Project Non-Contraceptive Indications for Hormonal Contraceptive Products - English PDF Non- ...
DEFF Research Database (Denmark)
Ernst, Erik
2003-01-01
This paper introduces the notion of higher-order inheritance hierarchies. They are useful because they provide well-known benefits of object-orientation at the level of entire hierarchies-benefits which are not available with current approaches. Three facets must be adressed: First, it must be po...
Multiple sclerosis and birth order.
James, W H
1984-01-01
Studies on the birth order of patients with multiple sclerosis have yielded contradictory conclusions. Most of the sets of data, however, have been tested by biased tests. Data that have been submitted to unbiased tests seem to suggest that cases are more likely to occur in early birth ranks. This should be tested on further samples and some comments are offered on how this should be done. PMID:6707558
Multiple sclerosis and birth order.
James, W H
1984-01-01
Studies on the birth order of patients with multiple sclerosis have yielded contradictory conclusions. Most of the sets of data, however, have been tested by biased tests. Data that have been submitted to unbiased tests seem to suggest that cases are more likely to occur in early birth ranks. This should be tested on further samples and some comments are offered on how this should be done.
DEFF Research Database (Denmark)
Israelsen, Stine Møller
This PhD thesis considers higher order modes (HOMs) in optical fibers. That includes their excitation and characteristics. Within the last decades, HOMs have been applied both for space multiplexing in optical communications, group velocity dispersion management and sensing among others......-radial polarization as opposed to the linear polarization of the LP0X modes. The effect is investigated numerically in a double cladding fiber with an outer aircladding using a full vectorial modesolver. Experimentally, the bowtie modes are excited using a long period grating and their free space characteristics...... and polarization state are investigated. For this fiber, the onset of the bowtie effect is shown numerically to be LP011. The characteristics usually associated with Bessel-likes modes such as long diffraction free length and selfhealing are shown to be conserved despite the lack of azimuthal symmetry...
Sonneveldt, Emily; DeCormier Plosky, Willyanne; Stover, John
2013-01-01
A number of data sets show that high parity births are associated with higher child mortality than low parity births. The reasons for this relationship are not clear. In this paper we investigate whether high parity is associated with lower coverage of key health interventions that might lead to increased mortality. We used DHS data from 10 high fertility countries to examine the relationship between parity and coverage for 8 child health intervention and 9 maternal health interventions. We also used the LiST model to estimate the effect on maternal and child mortality of the lower coverage associated with high parity births. Our results show a significant relationship between coverage of maternal and child health services and birth order, even when controlling for poverty. The association between coverage and parity for maternal health interventions was more consistently significant across countries all countries, while for child health interventions there were fewer overall significant relationships and more variation both between and within countries. The differences in coverage between children of parity 3 and those of parity 6 are large enough to account for a 12% difference in the under-five mortality rate and a 22% difference in maternal mortality ratio in the countries studied. This study shows that coverage of key health interventions is lower for high parity children and the pattern is consistent across countries. This could be a partial explanation for the higher mortality rates associated with high parity. Actions to address this gap could help reduce the higher mortality experienced by high parity birth.
Difference equations in massive higher order calculations
International Nuclear Information System (INIS)
Bierenbaum, I.; Bluemlein, J.; Klein, S.; Schneider, C.
2007-07-01
The calculation of massive 2-loop operator matrix elements, required for the higher order Wilson coefficients for heavy flavor production in deeply inelastic scattering, leads to new types of multiple infinite sums over harmonic sums and related functions, which depend on the Mellin parameter N. We report on the solution of these sums through higher order difference equations using the summation package Sigma. (orig.)
International Nuclear Information System (INIS)
Yuan Hong-Chun; Xiao Jin; Xiong Chao; Zhu Xi-Fang; Xu Xue-Xiang
2016-01-01
We explore two observable nonclassical properties of quantum states generated by repeatedly operating annihilation-then-creation (AC) and creation-then-annihilation (CA) on the coherent state, respectively, such as higher-order sub-Poissonian statistics and higher-order squeezing-enhanced effect. The corresponding analytical expressions are derived in detail depending on m . By numerically comparing those quantum properties, it is found that these states above have very different nonclassical properties and nonclassicality is exhibited more strongly after AC operation than after CA operation. (paper)
Multiple births associated with assisted human reproduction in Canada.
Cook, Jocelynn L; Geran, Leslie; Rotermann, Michelle
2011-06-01
Assisted human reproduction has been associated with increased rates of multiple births. Data suggest that twins and higher order multiple pregnancies are at risk for pre- and postnatal health complications that contribute to stress on both the family and the Canadian health care system. No published Canadian data estimate the contribution of assisted human reproduction to multiple birth rates. This study was designed to determine the contributions of age and assisted human reproduction to multiple birth rates in Canada. We performed analyses of existing Canadian databases, using a mathematical model from the Centers for Disease Control and Prevention. More specifically, data from the Canadian Vital Statistics: Births and Stillbirths database were combined with data from the Canadian Assisted Reproductive Technologies Register collected by the Canadian Fertility and Andrology Society. Datasets were standardized to age distributions of mothers in 1978. RESULTS suggest that in vitro fertilization, ovulation induction, and age each contribute more to the rates of triplets than to twins. As expected, the contribution of natural factors was higher to twins than to triplets. These are the first Canadian data analyzed to separate and measure the contributions of age and assisted reproductive technologies to multiple birth rates. Our findings are important for guiding physician and patient education and informing the development of treatment protocols that will result in lower-risk pregnancies and improved long-term health for women and their offspring.
A Paraconsistent Higher Order Logic
DEFF Research Database (Denmark)
Villadsen, Jørgen
2004-01-01
of paraconsistent logics in knowledge-based systems, logical semantics of natural language, etc. Higher order logics have the advantages of being expressive and with several automated theorem provers available. Also the type system can be helpful. We present a concise description of a paraconsistent higher order...... of the logic is examined by a case study in the domain of medicine. Thus we try to build a bridge between the HOL and MVL communities. A sequent calculus is proposed based on recent work by Muskens. Many non-classical logics are, at the propositional level, funny toys which work quite good, but when one wants...
Maltreatment in multiple-birth children.
Lang, Cathleen A; Cox, Matthew J; Flores, Glenn
2013-12-01
The rate of multiple births has increased over the last two decades. In 1982, an increased frequency of injuries among this patient population was noted, but few studies have evaluated the increased incidence of maltreatment in twins. The study aim was to evaluate the features of all multiple-birth children with substantiated physical abuse and/or neglect over a four-year period at a major children's hospital. A Retrospective chart review was conducted of multiple-gestation children in which at least one child in the multiple set experienced child maltreatment from January 2006 to December 2009. Data regarding the child, injuries, family, and perpetrators were abstracted. We evaluated whether family and child characteristics were associated with maltreatment, and whether types of injuries were similar within multiple sets. For comparison, data from the same time period for single-birth maltreated children also were abstracted, including child age, gestational age at birth, and injury type. There were 19 sets of multiple births in which at least one child had abusive injuries and/or neglect. In 10 of 19 sets (53%), all multiples were found to have a form of maltreatment, and all children in these multiple sets shared at least one injury type. Parents lived together in 63% of cases. Fathers and mothers were the alleged perpetrator in 42% of the cases. Multiple-gestation-birth maltreated children were significantly more likely than single-birth maltreated children to have abdominal trauma (13% vs. 1%, respectively; pchildren often, but not always, were abused. In sets with two maltreated children, children usually shared the same modes of maltreatment. Multiples are significantly more likely than singletons to be younger and experience fractures and abdominal trauma. The findings support the current standard practice of evaluating all children in a multiple set when one is found to be abused or neglected. Copyright © 2013 Elsevier Ltd. All rights reserved.
Nonlocal higher order evolution equations
Rossi, Julio D.; Schö nlieb, Carola-Bibiane
2010-01-01
In this article, we study the asymptotic behaviour of solutions to the nonlocal operator ut(x, t)1/4(-1)n-1 (J*Id -1)n (u(x, t)), x ∈ ℝN, which is the nonlocal analogous to the higher order local evolution equation vt(-1)n-1(Δ)nv. We prove
Prevalence of multiple birth in Isfahan, Iran
Directory of Open Access Journals (Sweden)
Ahmad Yazdekhasti
2018-01-01
Full Text Available Background: According to increasing rate of using assisted reproductive technology (ART which result in higher rates of multiple birth and natal difficulties, we aimed to determine the prevalence rate of multiple birth pregnancies. Materials and Methods: A descriptive cross-sectional study evaluating birth files in 2009–2010 of main hospitals of Isfahan, Iran. Results: Among 31640 files' studies, 614 cases of multiple birth pregnancies were investigated. The product of these pregnancies were 1286 (50.2% females infants including 557 twins (17.6/1000, 56 triplets (1.8/1000, and one case of quadruple (0.03/1000. Infants weigh <2500 g were 84.9% of all. Mothers had a mean age of 27.9 ± 4.9 which 30.4% of them had a positive history of using ART. Conclusion: The prevalence of multiple birth pregnancies is growing. The need for more mother and child care is important. Using ART world wide is leading more multiple birth which could be a cause for more complicated pregnancies.
Higher-Order Program Generation
DEFF Research Database (Denmark)
Rhiger, Morten
for OCaml, a dialect of ML, that provides run-time code generation for OCaml programs. We apply these byte-code combinators in semantics-directed compilation for an imperative language and in run-time specialization using type-directed partial evaluation. Finally, we present an approach to compiling goal......This dissertation addresses the challenges of embedding programming languages, specializing generic programs to specific parameters, and generating specialized instances of programs directly as executable code. Our main tools are higher-order programming techniques and automatic program generation....... It is our thesis that they synergize well in the development of customizable software. Recent research on domain-specific languages propose to embed them into existing general-purpose languages. Typed higher-order languages have proven especially useful as meta languages because they provide a rich...
Nonlocal higher order evolution equations
Rossi, Julio D.
2010-06-01
In this article, we study the asymptotic behaviour of solutions to the nonlocal operator ut(x, t)1/4(-1)n-1 (J*Id -1)n (u(x, t)), x ∈ ℝN, which is the nonlocal analogous to the higher order local evolution equation vt(-1)n-1(Δ)nv. We prove that the solutions of the nonlocal problem converge to the solution of the higher order problem with the right-hand side given by powers of the Laplacian when the kernel J is rescaled in an appropriate way. Moreover, we prove that solutions to both equations have the same asymptotic decay rate as t goes to infinity. © 2010 Taylor & Francis.
Classical higher-order processes
DEFF Research Database (Denmark)
Montesi, Fabrizio
2017-01-01
Classical Processes (CP) is a calculus where the proof theory of classical linear logic types processes à la Π-calculus, building on a Curry-Howard correspondence between session types and linear propositions. We contribute to this research line by extending CP with process mobility, inspired...... by the Higher-Order Π-calculus. The key to our calculus is that sequents are asymmetric: one side types sessions as in CP and the other types process variables, which can be instantiated with process values. The controlled interaction between the two sides ensures that process variables can be used at will......, but always respecting the linear usage of sessions expected by the environment....
Krasikova, Dina V; Le, Huy; Bachura, Eric
2018-01-22
To address a long-standing concern regarding a gap between organizational science and practice, scholars called for more intuitive and meaningful ways of communicating research results to users of academic research. In this article, we develop a common language effect size index (CLβ) that can help translate research results to practice. We demonstrate how CLβ can be computed and used to interpret the effects of continuous and categorical predictors in multiple linear regression models. We also elaborate on how the proposed CLβ index is computed and used to interpret interactions and nonlinear effects in regression models. In addition, we test the robustness of the proposed index to violations of normality and provide means for computing standard errors and constructing confidence intervals around its estimates. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Resilience and Higher Order Thinking
Directory of Open Access Journals (Sweden)
Ioan Fazey
2010-09-01
Full Text Available To appreciate, understand, and tackle chronic global social and environmental problems, greater appreciation of the importance of higher order thinking is required. Such thinking includes personal epistemological beliefs (PEBs, i.e., the beliefs people hold about the nature of knowledge and how something is known. These beliefs have profound implications for the way individuals relate to each other and the world, such as how people understand complex social-ecological systems. Resilience thinking is an approach to environmental stewardship that includes a number of interrelated concepts and has strong foundations in systemic ways of thinking. This paper (1 summarizes a review of educational psychology literature on PEBs, (2 explains why resilience thinking has potential to facilitate development of more sophisticated PEBs, (3 describes an example of a module designed to teach resilience thinking to undergraduate students in ways conducive to influencing PEBs, and (4 discusses a pilot study that evaluates the module's impact. Theoretical and preliminary evidence from the pilot evaluation suggests that resilience thinking which is underpinned by systems thinking has considerable potential to influence the development of more sophisticated PEBs. To be effective, however, careful consideration of how resilience thinking is taught is required. Finding ways to encourage students to take greater responsibility for their own learning and ensuring close alignment between assessment and desired learning outcomes are particularly important.
Higher-Order and Symbolic Computation
DEFF Research Database (Denmark)
Danvy, Olivier; Mason, Ian
2008-01-01
a series of implementaions that properly account for multiple invocations of the derivative-taking opeatro. In "Adapting Functional Programs to Higher-Order Logic," Scott Owens and Konrad Slind present a variety of examples of terminiation proofs of functional programs written in HOL proof systems. Since......-calculus programs, historically. The anaylsis determines the possible locations of ambients and mirrors the temporla sequencing of actions in the structure of types....
Low birth weight in relation to maternal age and multiple ...
African Journals Online (AJOL)
Vihar
Objectives: To determine the relationship between Low Birth Weight (LBW), maternal age and multiple ... mothers. Low socio-economic status is the underlying ... rate of low birth weight infants. ... Table 3: Distribution of Age against Birth weight.
A population-based study of effect of multiple birth on infant mortality in Nigeria
Directory of Open Access Journals (Sweden)
Uthman Mubashir B
2008-09-01
Full Text Available Abstract Background Multi-foetal pregnancies and multiple births including twins and higher order multiples births such as triplets and quadruplets are high-risk pregnancy and birth. These high-risk groups contribute to the higher rate of childhood mortality especially during early period of life. Methods We examined the relationship between multiple births and infant mortality using univariable and multivariable survival regression procedure with Weibull hazard function, controlling for child's sex, birth order, prenatal care, delivery assistance; mother's age at child birth, nutritional status, education level; household living conditions and several other risk factors. Results Children born multiple births were more than twice as likely to die during infancy as infants born singleton (hazard ratio = 2.19; 95% confidence interval: 1.50, 3.19 holding other factors constant. Maternal education and household asset index were associated with lower risk of infant mortality. Conclusion Multiple births are strongly negatively associated with infant survival in Nigeria independent of other risk factors. Mother's education played a protective role against infant death. This evidence suggests that improving maternal education may be key to improving child survival in Nigeria. A well-educated mother has a better chance of satisfying important factors that can improve infant survival: the quality of infant feeding, general care, household sanitation, and adequate use of preventive and curative health services.
Higher order mode optical fiber Raman amplifiers
DEFF Research Database (Denmark)
Rottwitt, Karsten; Friis, Søren Michael Mørk; Usuga Castaneda, Mario A.
2016-01-01
We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations.......We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations....
Challenges in higher order mode Raman amplifiers
DEFF Research Database (Denmark)
Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk
2015-01-01
A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...
Finding Higher Order Differentials of MISTY1
Tsunoo, Yukiyasu; Saito, Teruo; Kawabata, Takeshi; Nakagawa, Hirokatsu
MISTY1 is a 64-bit block cipher that has provable security against differential and linear cryptanalysis. MISTY1 is one of the algorithms selected in the European NESSIE project, and it is recommended for Japanese e-Government ciphers by the CRYPTREC project. In this paper, we report on 12th order differentials in 3-round MISTY1 with FL functions and 44th order differentials in 4-round MISTY1 with FL functions both previously unknown. We also report that both data complexity and computational complexity of higher order differential attacks on 6-round MISTY1 with FL functions and 7-round MISTY1 with FL functions using the 46th order differential can be reduced to as much as 1/22 of the previous values by using multiple 44th order differentials simultaneously.
Higher Order Expectations in Asset Pricing
Philippe BACCHETTA; Eric VAN WINCOOP
2004-01-01
We examine formally Keynes' idea that higher order beliefs can drive a wedge between an asset price and its fundamental value based on expected future payoffs. Higher order expectations add an additional term to a standard asset pricing equation. We call this the higher order wedge, which depends on the difference between higher and first order expectations of future payoffs. We analyze the determinants of this wedge and its impact on the equilibrium price. In the context of a dynamic noisy r...
Higher order harmonics of reactor neutron equation
International Nuclear Information System (INIS)
Li Fu; Hu Yongming; Luo Zhengpei
1996-01-01
The flux mapping method using the higher order harmonics of the neutron equation is proposed. Based on the bi-orthogonality of the higher order harmonics, the process and formulas for higher order harmonics calculation are derived via the source iteration method with source correction. For the first time, not only any order harmonics for up-to-3-dimensional geometry are achieved, but also the preliminary verification to the capability for flux mapping have been carried out
DEFF Research Database (Denmark)
Appel, Claus; van Oostrom, Vincent; Simonsen, Jakob Grue
2010-01-01
We show that, contrary to the situation in first-order term rewriting, almost none of the usual properties of rewriting are modular for higher-order rewriting, irrespective of the higher-order rewriting format. We show that for the particular format of simply typed applicative term rewriting...... systems modularity of confluence, normalization, and termination can be recovered by imposing suitable linearity constraints....
Higher-order techniques in computational electromagnetics
Graglia, Roberto D
2016-01-01
Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.
Higher-order rewriting and partial evaluation
DEFF Research Database (Denmark)
Danvy, Olivier; Rose, Kristoffer H.
1998-01-01
We demonstrate the usefulness of higher-order rewriting techniques for specializing programs, i.e., for partial evaluation. More precisely, we demonstrate how casting program specializers as combinatory reduction systems (CRSs) makes it possible to formalize the corresponding program...
Accounting for multiple births in randomised trials: a systematic review.
Yelland, Lisa Nicole; Sullivan, Thomas Richard; Makrides, Maria
2015-03-01
Multiple births are an important subgroup to consider in trials aimed at reducing preterm birth or its consequences. Including multiples results in a unique mixture of independent and clustered data, which has implications for the design, analysis and reporting of the trial. We aimed to determine how multiple births were taken into account in the design and analysis of recent trials involving preterm infants, and whether key information relevant to multiple births was reported. We conducted a systematic review of multicentre randomised trials involving preterm infants published between 2008 and 2013. Information relevant to multiple births was extracted. Of the 56 trials included in the review, 6 (11%) excluded multiples and 24 (43%) failed to indicate whether multiples were included. Among the 26 trials that reported multiples were included, only one (4%) accounted for clustering in the sample size calculations and eight (31%) took the clustering into account in the analysis of the primary outcome. Of the 20 trials that randomised infants, 12 (60%) failed to report how infants from the same birth were randomised. Information on multiple births is often poorly reported in trials involving preterm infants, and clustering due to multiple births is rarely taken into account. Since ignoring clustering could result in inappropriate recommendations for clinical practice, clustering should be taken into account in the design and analysis of future neonatal and perinatal trials including infants from a multiple birth. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
HIGHER ORDER THINKING IN TEACHING GRAMMAR
Directory of Open Access Journals (Sweden)
Citra Dewi
2017-04-01
Full Text Available The aim of this paper discussed about how to enhance students’ higher order thinking that should be done by teacher in teaching grammar. Usually teaching grammar was boring and has the same way to learn like change the pattern of sentence into positive, negative and introgative while the students’ need more various way to develop their thinking. The outcome of students’ competence in grammar sometimes not sufficient enough when the students’ occured some test international standart like Test of English Foreign Language, International English Language Testing. Whereas in TOEFL test it needed higher order thinking answer, so teacher should develop students’ higher order thingking in daily teaching grammar in order to make the students’ enhance their thinking are higher. The method was used in this paper by using field study based on the experience of teaching grammar. It can be shown by students’ toefl score was less in stucture and written expression. The result of this paper was after teacher gave some treatments to enhance students’ higher order thinking in teaching grammar, the students’ toefl scores are sufficient enough as a part of stucture and written expression. It can concluded that it needed some strategies to enhancce students higher order thinking by teaching grammar it can make students’ higher toefl score. Teachers should be creative and inovative to teach the students’ started from giving the students’ question or test in teaching grammar.
Electromagnetic cloaking in higher order spherical cloaks
Sidhwa, H. H.; Aiyar, R. P. R. C.; Kulkarni, S. V.
2017-06-01
The inception of transformation optics has led to the realisation of the invisibility devices for various applications, one of which is spherical cloaking. In this paper, a formulation for a higher-order spherical cloak has been proposed to reduce its physical thickness significantly by introducing a nonlinear relation between the original and transformed coordinate systems and it has been verified using the ray tracing approach. Analysis has been carried out to observe the anomalies in the variation of refractive index for higher order cloaks indicating the presence of poles in the relevant equations. Furthermore, a higher-order spherical cloak with predefined values of the material characteristics on its inner and outer surfaces has been designed for practical application.
Higher-order force gradient symplectic algorithms
Chin, Siu A.; Kidwell, Donald W.
2000-12-01
We show that a recently discovered fourth order symplectic algorithm, which requires one evaluation of force gradient in addition to three evaluations of the force, when iterated to higher order, yielded algorithms that are far superior to similarly iterated higher order algorithms based on the standard Forest-Ruth algorithm. We gauge the accuracy of each algorithm by comparing the step-size independent error functions associated with energy conservation and the rotation of the Laplace-Runge-Lenz vector when solving a highly eccentric Kepler problem. For orders 6, 8, 10, and 12, the new algorithms are approximately a factor of 103, 104, 104, and 105 better.
Season of birth and multiple sclerosis in Tunisia.
Sidhom, Youssef; Kacem, Imen; Bayoudh, Lamia; Ben Djebara, Mouna; Hizem, Yosr; Ben Abdelfettah, Sami; Gargouri, Amina; Gouider, Riadh
2015-11-01
Recent studies on date of birth of multiple sclerosis (MS) patients showed an association between month of birth and the risk of developing MS. This association has not been investigated in an African country. We aimed to determine if the risk of MS is associated with month of birth in Tunisia. Data concerning date of birth for MS patients in Tunisia (n = 1912) was obtained. Birth rates of MS patients were compared with all births in Tunisia matched by year of birth (n = 11,615,912). We used a chi-squared analysis and the Hewitt's non-parametric test for seasonality. The distribution of births among MS patients compared with the control population was not different when tested by the chi-squared test. The Hewitt's test for seasonality showed an excess of births between May and October among MS patients (p = 0.03). The peak of Births of MS patients in Tunisia was in July and the nadir in December. Our data does support the seasonality hypothesis of month of birth as risk factor for MS in Tunisia. Low vitamin D levels during pregnancy could be a possible explanation that needs further investigation. Copyright © 2015 Elsevier B.V. All rights reserved.
Frontiers of higher order fuzzy sets
Tahayori, Hooman
2015-01-01
Frontiers of Higher Order Fuzzy Sets, strives to improve the theoretical aspects of general and Interval Type-2 fuzzy sets and provides a unified representation theorem for higher order fuzzy sets. Moreover, the book elaborates on the concept of gradual elements and their integration with the higher order fuzzy sets. This book also introduces new frameworks for information granulation based on general T2FSs, IT2FSs, Gradual elements, Shadowed sets and rough sets. In particular, the properties and characteristics of the new proposed frameworks are studied. Such new frameworks are shown to be more capable to be exploited in real applications. Higher order fuzzy sets that are the result of the integration of general T2FSs, IT2FSs, gradual elements, shadowed sets and rough sets will be shown to be suitable to be applied in the fields of bioinformatics, business, management, ambient intelligence, medicine, cloud computing and smart grids. Presents new variations of fuzzy set frameworks and new areas of applicabili...
Higher-order tensors in diffusion imaging
Schultz, T.; Fuster, A.; Ghosh, A.; Deriche, R.; Florack, L.M.J.; Lim, L.H.; Westin, C.-F.; Vilanova, A.; Burgeth, B.
2014-01-01
Diffusion imaging is a noninvasive tool for probing the microstructure of fibrous nerve and muscle tissue. Higher-order tensors provide a powerful mathematical language to model and analyze the large and complex data that is generated by its modern variants such as High Angular Resolution Diffusion
Analogy, higher order thinking, and education.
Richland, Lindsey Engle; Simms, Nina
2015-01-01
Analogical reasoning, the ability to understand phenomena as systems of structured relationships that can be aligned, compared, and mapped together, plays a fundamental role in the technology rich, increasingly globalized educational climate of the 21st century. Flexible, conceptual thinking is prioritized in this view of education, and schools are emphasizing 'higher order thinking', rather than memorization of a cannon of key topics. The lack of a cognitively grounded definition for higher order thinking, however, has led to a field of research and practice with little coherence across domains or connection to the large body of cognitive science research on thinking. We review literature on analogy and disciplinary higher order thinking to propose that relational reasoning can be productively considered the cognitive underpinning of higher order thinking. We highlight the utility of this framework for developing insights into practice through a review of mathematics, science, and history educational contexts. In these disciplines, analogy is essential to developing expert-like disciplinary knowledge in which concepts are understood to be systems of relationships that can be connected and flexibly manipulated. At the same time, analogies in education require explicit support to ensure that learners notice the relevance of relational thinking, have adequate processing resources available to mentally hold and manipulate relations, and are able to recognize both the similarities and differences when drawing analogies between systems of relationships. © 2015 John Wiley & Sons, Ltd.
Higher-Order Components for Grid Programming
Dünnweber, Jan
2009-01-01
Higher-Order Components were developed within the CoreGRID European Network of Excellence and have become an optional extension of the popular Globus middleware. This book provides the reader with hands-on experience, describing a collection of example applications from various fields of science and engineering, including biology and physics.
Higher order antibunching in intermediate states
International Nuclear Information System (INIS)
Verma, Amit; Sharma, Navneet K.; Pathak, Anirban
2008-01-01
Since the introduction of binomial state as an intermediate state, different intermediate states have been proposed. Different nonclassical effects have also been reported in these intermediate states. But till now higher order antibunching is predicted in only one type of intermediate state, which is known as shadowed negative binomial state. Recently we have shown that the higher order antibunching is not a rare phenomenon [P. Gupta, P. Pandey, A. Pathak, J. Phys. B 39 (2006) 1137]. To establish our earlier claim further, here we have shown that the higher order antibunching can be seen in different intermediate states, such as binomial state, reciprocal binomial state, hypergeometric state, generalized binomial state, negative binomial state and photon added coherent state. We have studied the possibility of observing the higher order subpoissonian photon statistics in different limits of intermediate states. The effects of different control parameters on the depth of non classicality have also been studied in this connection and it has been shown that the depth of nonclassicality can be tuned by controlling various physical parameters
Certified higher-order recursive path ordering
Koprowski, A.; Pfenning, F.
2006-01-01
The paper reports on a formalization of a proof of wellfoundedness of the higher-order recursive path ordering (HORPO) in the proof checker Coq. The development is axiom-free and fully constructive. Three substantive parts that could be used also in other developments are the formalizations of the
Higher-Order Minimal Functional Graphs
DEFF Research Database (Denmark)
Jones, Neil D; Rosendahl, Mads
1994-01-01
We present a minimal function graph semantics for a higher-order functional language with applicative evaluation order. The semantics captures the intermediate calls performed during the evaluation of a program. This information may be used in abstract interpretation as a basis for proving...
The correspondence between interracial births and multiple-race reporting.
Parker, Jennifer D; Madans, Jennifer H
2002-12-01
Race-specific health statistics are routinely reported in scientific publications; most describe health disparities across groups. Census 2000 showed that 2.4% of the US population identifies with more than 1 race group. We examined the hypothesis that multiple-race reporting is associated with interracial births by comparing parental race reported on birth certificates with reported race in a national health survey. US natality data from 1968 through 1998 and National Health Interview Survey data from 1990 through 1998 were compared, by year of birth. Overall multiple-race survey responses correspond to expectations from interracial births. However, there are discrepancies for specific multiple-race combinations. Projected estimates of the multiple-race population can be only partially informed by vital records.
A Higher-Order Colon Translation
DEFF Research Database (Denmark)
Danvy, Olivier; Nielsen, Lasse Reichstein
2001-01-01
A lambda-encoding such as the CPS transformation gives rise to administrative redexes. In his seminal article ``Call-by-name, call-by-value and the lambda-calculus'', 25 years ago, Plotkin tackled administrative reductions using a so-called ``colon translation.'' 10 years ago, Danvy and Filinski...... integrated administrative reductions in the CPS transformation, making it operate in one pass. The technique applies to other lambda-encodings (e.g., variants of CPS), but we do not see it used in practice--instead, Plotkin's colon translation appears to be favored. Therefore, in an attempt to link both...... techniques, we recast Plotkin's proof of Indifference and Simulation to the higher-order specification of the one-pass CPS transformation. To this end, we extend his colon translation from first order to higher order...
XY model with higher-order exchange.
Žukovič, Milan; Kalagov, Georgii
2017-08-01
An XY model, generalized by inclusion of up to an infinite number of higher-order pairwise interactions with an exponentially decreasing strength, is studied by spin-wave theory and Monte Carlo simulations. At low temperatures the model displays a quasi-long-range-order phase characterized by an algebraically decaying correlation function with the exponent η=T/[2πJ(p,α)], nonlinearly dependent on the parameters p and α that control the number of the higher-order terms and the decay rate of their intensity, respectively. At higher temperatures the system shows a crossover from the continuous Berezinskii-Kosterlitz-Thouless to the first-order transition for the parameter values corresponding to a highly nonlinear shape of the potential well. The role of topological excitations (vortices) in changing the nature of the transition is discussed.
Lagrangian procedures for higher order field equations
International Nuclear Information System (INIS)
Bollini, C.G.
1987-01-01
A Lagrangian procedure for a pedagogical way is presented for the treatment of higher order field equations. The energy-momentum tensor and the conserved density current are built. In particular the case in which the derivatives appear only in the invariant D'Alembertian operator is discussed. Some examples are discussed. The fields are quantized and the corresponding Hamilonian which is shown not to be positive defructed. Rules are given to write the causal propagators. (author) [pt
Lagrangian procedures for higher order field equations
International Nuclear Information System (INIS)
Bollini, C.G.; Giambiagi, J.J.
1986-01-01
We present in a pedagogical way a Lagrangian procedure for the treatment of higher order field equations. We build the energy-momentum tensor and the conserved density current. In particular we discuss the case in which the derivatives appear only in the invariant D'Alembertian operator. We discuss some examples. We quantize the fields and construct the corresponding Hamiltonian which is shown not to be positive definite. We give the rules for the causal propagators. (Author) [pt
Higher order correlations in computed particle distributions
International Nuclear Information System (INIS)
Hanerfeld, H.; Herrmannsfeldt, W.; Miller, R.H.
1989-03-01
The rms emittances calculated for beam distributions using computer simulations are frequently dominated by higher order aberrations. Thus there are substantial open areas in the phase space plots. It has long been observed that the rms emittance is not an invariant to beam manipulations. The usual emittance calculation removes the correlation between transverse displacement and transverse momentum. In this paper, we explore the possibility of defining higher order correlations that can be removed from the distribution to result in a lower limit to the realizable emittance. The intent is that by inserting the correct combinations of linear lenses at the proper position, the beam may recombine in a way that cancels the effects of some higher order forces. An example might be the non-linear transverse space charge forces which cause a beam to spread. If the beam is then refocused so that the same non-linear forces reverse the inward velocities, the resulting phase space distribution may reasonably approximate the original distribution. The approach to finding the location and strength of the proper lens to optimize the transported beam is based on work by Bruce Carlsten of Los Alamos National Laboratory. 11 refs., 4 figs
Reference birthweight range for multiple birth neonates in Japan
Directory of Open Access Journals (Sweden)
Kato Noriko
2004-02-01
Full Text Available Abstract Background A reference range for the birthweight of multiple births neonates is necessary for the assessment for intrauterine growth. Methods Pairs of multiple births were identified by birthplace, the ages of the parents, gestational age, and the year and month of birth. We studied a total of 32,232 livebirth-livebirth pairs of twins, 1894 triplet live births, and 206 quadruplet live births. Results The median birthweight of males, taking gestational age into account, was ca. 0.05 kg–0.1 kg heavier than that of females. Compared to singleton neonates, the median birthweight of twins was ca. 0.15 kg smaller at the gestational age of 34 weeks, increasing to ca. 0.5 kg at 42 weeks of gestation. As for birth order, the mean birthweight of the first-born twin was heavier than that of the second-born. The standard deviation of birthweight was larger for second-born twins. The birthweight of twins from multiparous mothers was greater than those from primiparous mothers. The median birthweight according to gestational age was found to be the greatest in twins, lower in triplets and the lowest in quadruplets. In triplets, the 50th percentile was 0.08 kg heavier in boys than for girls. Conclusion Our results can be used for assessment of birthweight of multiple births in Japan.
Higher order modes of coupled optical fibres
International Nuclear Information System (INIS)
Alexeyev, C N; Yavorsky, M A; Boklag, N A
2010-01-01
The structure of hybrid higher order modes of two coupled weakly guiding identical optical fibres is studied. On the basis of perturbation theory with degeneracy for the vector wave equation expressions for modes with azimuthal angular number l ≥ 1 are obtained that allow for the spin–orbit interaction. The spectra of polarization corrections to the scalar propagation constants are calculated in a wide range of distances between the fibres. The limiting cases of widely and closely spaced fibres are studied. The obtained results can be used for studying the tunnelling of optical vortices in directional couplers and in matters concerned with information security
Ward identities of higher order Virasoro algebra
International Nuclear Information System (INIS)
Zha Chaozeng; Dolate, S.
1994-11-01
The general formulations of primary fields versus quasi-primary ones in the context of high order Virasoro algebra (HOVA) and the corresponding Ward identity are explored. The primary fields of conformal spins up to 8 are given in terms of quasi-primary fields, and the general features of the higher order expressions are also discussed. It is observed that the local fields, either primary of quasi-primary, carry the same numbers of central charges, and not all the primary fields contribute to the anomalies in the Ward identities. (author). 6 refs
Theorem Proving In Higher Order Logics
Carreno, Victor A. (Editor); Munoz, Cesar A.; Tahar, Sofiene
2002-01-01
The TPHOLs International Conference serves as a venue for the presentation of work in theorem proving in higher-order logics and related areas in deduction, formal specification, software and hardware verification, and other applications. Fourteen papers were submitted to Track B (Work in Progress), which are included in this volume. Authors of Track B papers gave short introductory talks that were followed by an open poster session. The FCM 2002 Workshop aimed to bring together researchers working on the formalisation of continuous mathematics in theorem proving systems with those needing such libraries for their applications. Many of the major higher order theorem proving systems now have a formalisation of the real numbers and various levels of real analysis support. This work is of interest in a number of application areas, such as formal methods development for hardware and software application and computer supported mathematics. The FCM 2002 consisted of three papers, presented by their authors at the workshop venue, and one invited talk.
Higher order cumulants in colorless partonic plasma
Energy Technology Data Exchange (ETDEWEB)
Cherif, S. [Sciences and Technologies Department, University of Ghardaia, Ghardaia, Algiers (Algeria); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ahmed, M. A. A. [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Department of Physics, Taiz University in Turba, Taiz (Yemen); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ladrem, M., E-mail: mladrem@yahoo.fr [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria)
2016-06-10
Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume T{sub 0}(V), a new approach based on the finite-size cumulant expansion of the order parameter and the ℒ{sub m,n}-Method is used. We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase transition point. In the context of our model, we have shown that the finite volume transition point is always associated to the appearance of a particular point in whole higher order cumulants under consideration.
Three weights higher order Hardy type inequalities
Directory of Open Access Journals (Sweden)
Aigerim A. Kalybay
2006-01-01
Full Text Available We investigate the following three weights higher order Hardy type inequality (0.1 ‖g‖q,u≤ C‖Dρkg‖p,v where Dρi denotes the following weighted differential operator: {dig(tdti,i=0,1,...,m−1,di−mdti−m(p(tdmg(tdtm,i=m,m+1,...,k, for a weight function ρ(⋅. A complete description of the weights u, v and ρ so that (0.1 holds was given in [4] for the case 1
Reducing multiple births in assisted reproduction technology.
Bhattacharya, Siladitya; Kamath, Mohan S
2014-02-01
Multiple pregnancy, a complication of assisted reproduction technology, is associated with poorer maternal and perinatal outcomes. The primary reason behind this is the strategy of replacing more than one embryo during an assisted reproduction technology cycle to maximise pregnancy rates. The solution to this problem is to reduce the number of embryos transferred during in-vitro fertilisation. The transition from triple- to double-embryo transfer, which decreased the risk of triplets without compromising pregnancy rates, was easily implemented. The adoption of a single embryo transfer policy has been slow because of concerns about impaired pregnancy rates in a fresh assisted reproduction technology cycle. Widespread availability of effective cryopreservation programmes means that elective single embryo transfer, along with subsequent frozen embryo transfers, could provide a way forward. Any such strategy will need to consider couples' preferences and existing funding policies, both of which have a profound influence on decision making around embryo transfer. Copyright © 2013 Elsevier Ltd. All rights reserved.
Chambers, Georgina M; Hoang, Van Phuong; Lee, Evelyn; Hansen, Michele; Sullivan, Elizabeth A; Bower, Carol; Chapman, Michael
2014-11-01
The unprecedented increase in multiple births during the past 3 decades is a major public health concern and parallels the uptake of medically assisted conception. The economic implications of such births are not well understood. To conduct a comprehensive economic and health services assessment of the frequency, duration, and cost of hospital admissions during the first 5 years of life for singleton, twin, and higher-order multiple (HOM) children and to examine the contribution of assisted reproductive technology (ART) to the incidence and cost of multiple births. A retrospective population cohort study using individually linked birth, hospital, and death records among 233,850 infants born in Western Australia between October 1993 and September 2003, and followed up to September 2008. Multiple-gestation delivery and ART conception. Odds of stillbirth, prematurity and low birth weight, frequency and length of hospital admissions, the mean costs by plurality, and the independent effect of prematurity on childhood costs. Of 226,624 singleton, 6941 twin, and 285 HOM infants, 1.0% of singletons, 15.4% of twins, and 34.7% of HOM children were conceived following ART. Compared with singletons, twins and HOMs were 3.4 and 9.6 times, respectively, more likely to be stillborn and were 6.4 and 36.7 times, respectively, more likely to die during the neonatal period. Twins and HOMs were 18.7 and 525.1 times, respectively, more likely to be preterm, and 3.6 and 2.8 times, respectively, more likely to be small for gestational age. The mean hospital costs of a singleton, twin, and HOM child to age 5 years were $2730, $8993, and $24,411 (in 2009-2010 US dollars), respectively, with cost differences concentrated in the neonatal period and during the first year of life. Almost 15% of inpatient costs for multiple births could have been avoided if ART twins and HOMs had been born as singletons. Compared with singletons, multiple-birth infants consume significantly more hospital
Higher order mode damping in Kaon factory RF cavities
International Nuclear Information System (INIS)
Enegren, T.; Poirier, R.; Griffin, J.; Walling, L.; Thiessen, H.A.; Smythe, W.R.
1989-05-01
Proposed designs for Kaon factory accelerators require that the rf cavities support beam currents on the order of several amperes. The beam current has Fourier components at all multiples of the rf frequency. Empty rf buckets produce additional components at all multiples of the revolution frequency. If a Fourier component of the beam coincides with the resonant frequency of a higher order mode of the cavity, which is inevitable if the cavity has a large frequency swing, significant excitation of this mode can occur. The induced voltage may then excite coupled bunch mode instabilities. Effective means are required to damp higher order modes without significantly affecting the fundamental mode. A mode damping scheme based on coupled transmission lines has been investigated and is report
Non-Poisson Dichotomous Noise: Higher-Order Correlation Functions and Aging
National Research Council Canada - National Science Library
Allegrini, Paolo; Grigolini, Paolo; Palatella, Luigi; West, Bruce J
2004-01-01
.... The transition of psi(tau) from the exponential to the nonexponential condition yields the breakdown of the usual factorization condition of higher-order correlation functions, as well as the birth of aging effects...
Choi, Sun Hee; Park, Young Sil; Shim, Kye Shik; Choi, Yong Sung; Chang, Ji Young; Hahn, Won Ho; Bae, Chong-Woo
2010-08-01
The aim of this study was to survey multiple birth data and to analyze the recent trends of multiple births and its consequences on perinatal problems in Korea from 1991 to 2008. Data were obtained from the Korean Statistical Information Service. The total number of multiple births showed increasing trends. The multiple birth rate was maintained within less than 10.0 for the decade from 1981 to 1990. However, it increased gradually to reach 27.5 in 2008. The maternal age for multiple births was higher than for total live births. The mean birth weight of the total live births was 3.23 kg; for the multiple births it was 2.40 kg in 2008. The incidence of low birth weight infants (LBWI) among total live births was 3.8% in 2000 and 4.9% in 2008. For multiple births it was 49.2% and 53.0% during the same years. The incidence of preterm births among total live births was 3.8% in 2000 and 5.5% in 2008; for the multiple births it was 38.3% and 51.5% during the same years. The incidence of multiple births and its consequences on perinatal problems (preterm, LBWI, and advanced-maternal age) have been increased steadily over the last two decades in Korea.
Multilinear operators for higher-order decompositions.
Energy Technology Data Exchange (ETDEWEB)
Kolda, Tamara Gibson
2006-04-01
We propose two new multilinear operators for expressing the matrix compositions that are needed in the Tucker and PARAFAC (CANDECOMP) decompositions. The first operator, which we call the Tucker operator, is shorthand for performing an n-mode matrix multiplication for every mode of a given tensor and can be employed to concisely express the Tucker decomposition. The second operator, which we call the Kruskal operator, is shorthand for the sum of the outer-products of the columns of N matrices and allows a divorce from a matricized representation and a very concise expression of the PARAFAC decomposition. We explore the properties of the Tucker and Kruskal operators independently of the related decompositions. Additionally, we provide a review of the matrix and tensor operations that are frequently used in the context of tensor decompositions.
Trends in preterm birth: singleton and multiple pregnancies in the Netherlands, 2000-2007.
Schaaf, J M; Mol, B W J; Abu-Hanna, A; Ravelli, A C J
2011-09-01
Several studies have reported increasing trends in preterm birth in developed countries, mainly attributable to an increase in medically indicated preterm births. Our aim was to describe trends in preterm birth among singleton and multiple pregnancies in the Netherlands. Prospective cohort study. Nationwide study. We studied 1,451,246 pregnant women from 2000 to 2007. We assessed trends in preterm birth. We subdivided preterm birth into spontaneous preterm birth after premature prelabour rupture of membranes (pPROM), medically indicated preterm birth and spontaneous preterm birth without pPROM. We performed analyses separately for singletons and multiples. The primary outcome was preterm birth, defined as birth before 37 weeks of gestation, with very preterm birth (birth was 7.7% and the risk of very preterm birth was 1.3%. In singleton pregnancies, the preterm birth risk decreased significantly from 6.4% to 6.0% (P birth without pPROM (3.6-3.1%, P birth risk increased significantly (47.3-47.7%, P = 0.047), mainly as a result of medically indicated preterm birth, which increased from 15.0% to 17.9% (P birth risk in singleton pregnancies decreased significantly over the years. The trend of increasing preterm birth risk reported in other countries was only observed in (medically indicated) preterm birth in multiple pregnancies. © 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG.
Trends in the prevalence, risk and pregnancy outcome of multiple births with congenital anomaly
DEFF Research Database (Denmark)
Boyle, B; McConkey, R; Garne, E
2013-01-01
To assess the public health consequences of the rise in multiple births with respect to congenital anomalies.......To assess the public health consequences of the rise in multiple births with respect to congenital anomalies....
Compiler-Directed Transformation for Higher-Order Stencils
Energy Technology Data Exchange (ETDEWEB)
Basu, Protonu [Univ. of Utah, Salt Lake City, UT (United States); Hall, Mary [Univ. of Utah, Salt Lake City, UT (United States); Williams, Samuel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Straalen, Brian Van [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Oliker, Leonid [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Colella, Phillip [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2015-07-20
As the cost of data movement increasingly dominates performance, developers of finite-volume and finite-difference solutions for partial differential equations (PDEs) are exploring novel higher-order stencils that increase numerical accuracy and computational intensity. This paper describes a new compiler reordering transformation applied to stencil operators that performs partial sums in buffers, and reuses the partial sums in computing multiple results. This optimization has multiple effect son improving stencil performance that are particularly important to higher-order stencils: exploits data reuse, reduces floating-point operations, and exposes efficient SIMD parallelism to backend compilers. We study the benefit of this optimization in the context of Geometric Multigrid (GMG), a widely used method to solvePDEs, using four different Jacobi smoothers built from 7-, 13-, 27-and 125-point stencils. We quantify performance, speedup, andnumerical accuracy, and use the Roofline model to qualify our results. Ultimately, we obtain over 4× speedup on the smoothers themselves and up to a 3× speedup on the multigrid solver. Finally, we demonstrate that high-order multigrid solvers have the potential of reducing total data movement and energy by several orders of magnitude.
Higher-order Peregrine combs and Peregrine walls for the variable-coefficient Lenells-Fokas equation
Wang, Zi-Qi; Wang, Xin; Wang, Lei; Sun, Wen-Rong; Qi, Feng-Hua
2017-02-01
In this paper, we study the variable-coefficient Lenells-Fokas (LF) model. Under large periodic modulations in the variable coefficients of the LF model, the generalized Akhmediev breathers develop into the breather multiple births (BMBs) from which we obtain the Peregrine combs (PCs). The PCs can be considered as the limiting case of the BMBs and be transformed into the Peregrine walls (PWs) with a specific amplitude of periodic modulation. We further investigate the spatiotemporal characteristics of the PCs and PWs analytically. Based on the second-order breather and rogue-wave solutions, we derive the corresponding higher-order structures (higher-order PCs and PWs) under proper periodic modulations. What is particularly noteworthy is that the second-order PC can be converted into the Peregrine pyramid which exhibits the higher amplitude and thickness. Our results could be helpful for the design of experiments in the optical fiber communications.
Conceptualizing and Assessing Higher-Order Thinking in Reading
Afflerbach, Peter; Cho, Byeong-Young; Kim, Jong-Yun
2015-01-01
Students engage in higher-order thinking as they read complex texts and perform complex reading-related tasks. However, the most consequential assessments, high-stakes tests, are currently limited in providing information about students' higher-order thinking. In this article, we describe higher-order thinking in relation to reading. We provide a…
Higher-Order Generalized Invexity in Control Problems
Directory of Open Access Journals (Sweden)
S. K. Padhan
2011-01-01
Full Text Available We introduce a higher-order duality (Mangasarian type and Mond-Weir type for the control problem. Under the higher-order generalized invexity assumptions on the functions that compose the primal problems, higher-order duality results (weak duality, strong duality, and converse duality are derived for these pair of problems. Also, we establish few examples in support of our investigation.
Skinner-Rusk unified formalism for higher-order systems
Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso
2012-07-01
The Lagrangian-Hamiltonian unified formalism of R. Skinner and R. Rusk was originally stated for autonomous dynamical systems in classical mechanics. It has been generalized for non-autonomous first-order mechanical systems, first-order and higher-order field theories, and higher-order autonomous systems. In this work we present a generalization of this formalism for higher-order non-autonomous mechanical systems.
Nil Bohr-sets and almost automorphy of higher order
Huang, Wen; Ye, Xiangdong
2016-01-01
Two closely related topics, higher order Bohr sets and higher order almost automorphy, are investigated in this paper. Both of them are related to nilsystems. In the first part, the problem which can be viewed as the higher order version of an old question concerning Bohr sets is studied: for any d\\in \\mathbb{N} does the collection of \\{n\\in \\mathbb{Z}: S\\cap (S-n)\\cap\\ldots\\cap (S-dn)\
Trends in preterm birth: singleton and multiple pregnancies in the Netherlands, 2000-2007
Schaaf, J. M.; Mol, B. W. J.; Abu-Hanna, A.; Ravelli, A. C. J.
2011-01-01
Several studies have reported increasing trends in preterm birth in developed countries, mainly attributable to an increase in medically indicated preterm births. Our aim was to describe trends in preterm birth among singleton and multiple pregnancies in the Netherlands. Prospective cohort study.
Higher-Order Hybrid Gaussian Kernel in Meshsize Boosting Algorithm
African Journals Online (AJOL)
In this paper, we shall use higher-order hybrid Gaussian kernel in a meshsize boosting algorithm in kernel density estimation. Bias reduction is guaranteed in this scheme like other existing schemes but uses the higher-order hybrid Gaussian kernel instead of the regular fixed kernels. A numerical verification of this scheme ...
Higher-order Jordan Osserman pseudo-Riemannian manifolds
International Nuclear Information System (INIS)
Gilkey, Peter B; Ivanova, Raina; Zhang Tan
2002-01-01
We study the higher-order Jacobi operator in pseudo-Riemannian geometry. We exhibit a family of manifolds so that this operator has constant Jordan normal form on the Grassmannian of subspaces of signature (r, s) for certain values of (r, s). These pseudo-Riemannian manifolds are new and non-trivial examples of higher-order Osserman manifolds
Higher-order Jordan Osserman pseudo-Riemannian manifolds
Energy Technology Data Exchange (ETDEWEB)
Gilkey, Peter B [Mathematics Department, University of Oregon, Eugene, OR 97403 (United States); Ivanova, Raina [Mathematics Department, University of Hawaii - Hilo, 200 W Kawili St, Hilo, HI 96720 (United States); Zhang Tan [Department of Mathematics and Statistics, Murray State University, Murray, KY 42071 (United States)
2002-09-07
We study the higher-order Jacobi operator in pseudo-Riemannian geometry. We exhibit a family of manifolds so that this operator has constant Jordan normal form on the Grassmannian of subspaces of signature (r, s) for certain values of (r, s). These pseudo-Riemannian manifolds are new and non-trivial examples of higher-order Osserman manifolds.
Exact solutions to two higher order nonlinear Schroedinger equations
International Nuclear Information System (INIS)
Xu Liping; Zhang Jinliang
2007-01-01
Using the homogeneous balance principle and F-expansion method, the exact solutions to two higher order nonlinear Schroedinger equations which describe the propagation of femtosecond pulses in nonlinear fibres are obtained with the aid of a set of subsidiary higher order ordinary differential equations (sub-equations for short)
Neural classifiers for learning higher-order correlations
International Nuclear Information System (INIS)
Gueler, M.
1999-01-01
Studies by various authors suggest that higher-order networks can be more powerful and biologically more plausible with respect to the more traditional multilayer networks. These architecture make explicit use of nonlinear interactions between input variables in the form of higher-order units or product units. If it is known a priori that the problem to be implemented possesses a given set of invariances like in the translation, rotation, and scale invariant recognition problems, those invariances can be encoded, thus eliminating all higher-order terms which are incompatible with the invariances. In general, however, it is a serious set-back that the complexity of learning increases exponentially with the size of inputs. This paper reviews higher-order networks and introduces an implicit representation in which learning complexity is mainly decided by the number of higher-order terms to be learned and increases only linearly with the input size
Neural Classifiers for Learning Higher-Order Correlations
Güler, Marifi
1999-01-01
Studies by various authors suggest that higher-order networks can be more powerful and are biologically more plausible with respect to the more traditional multilayer networks. These architectures make explicit use of nonlinear interactions between input variables in the form of higher-order units or product units. If it is known a priori that the problem to be implemented possesses a given set of invariances like in the translation, rotation, and scale invariant pattern recognition problems, those invariances can be encoded, thus eliminating all higher-order terms which are incompatible with the invariances. In general, however, it is a serious set-back that the complexity of learning increases exponentially with the size of inputs. This paper reviews higher-order networks and introduces an implicit representation in which learning complexity is mainly decided by the number of higher-order terms to be learned and increases only linearly with the input size.
Confounding Underlies the Apparent Month of Birth Effect in Multiple Sclerosis
Fiddes, Barnaby; Wason, James; Kemppinen, Anu; Ban, Maria; Compston, Alastair; Sawcer, Stephen
2013-01-01
Objective Several groups have reported apparent association between month of birth and multiple sclerosis. We sought to test the extent to which such studies might be confounded by extraneous variables such as year and place of birth. Methods Using national birth statistics from 2 continents, we assessed the evidence for seasonal variations in birth rate and tested the extent to which these are subject to regional and temporal variation. We then established the age and regional origin distrib...
Higher order Lie-Baecklund symmetries of evolution equations
International Nuclear Information System (INIS)
Roy Chowdhury, A.; Roy Chowdhury, K.; Paul, S.
1983-10-01
We have considered in detail the analysis of higher order Lie-Baecklund symmetries for some representative nonlinear evolution equations. Until now all such symmetry analyses have been restricted only to the first order of the infinitesimal parameter. But the existence of Baecklund transformation (which can be shown to be an overall sum of higher order Lie-Baecklund symmetries) makes it necessary to search for such higher order Lie-Baecklund symmetries directly without taking recourse to the Baecklund transformation or inverse scattering technique. (author)
The differential geometry of higher order jets and tangent bundles
International Nuclear Information System (INIS)
De Leon, M.; Rodrigues, P.R.
1985-01-01
This chapter is devoted to the study of basic geometrical notions required for the development of the main object of the text. Some facts about Jet theory are reviewed. A particular case of Jet manifolds is considered: the tangent bundle of higher order. It is shown that this jet bundle possesses in a canonical way a certain kind of geometric structure, the so called almost tangent structure of higher order, and which is a generalization of the almost tangent geometry of the tangent bundle. Another important fact examined is the extension of the notion of 'spray' to higher order tangent bundles. (Auth.)
Higher-order harmonics of general limited diffraction Bessel beams
International Nuclear Information System (INIS)
Ding De-Sheng; Huang Jin-Huang
2016-01-01
In this paper, we extensively study the higher-order harmonic generation of the general limited diffraction m -th-order Bessel beam. The analysis is based on successive approximations of the Khokhlov–Zabolotskaya–Kuznetsov (KZK) equation. Asymptotic expansions are presented for higher-order harmonic Bessel beams in near and far fields. The validity of asymptotic approximation is also analyzed. The higher-order harmonic of the Bessel beam with the lowest zero-order is taken as a special example. (special topic)
Higher-order harmonics of general limited diffraction Bessel beams
Ding, De-Sheng; Huang, Jin-Huang
2016-12-01
In this paper, we extensively study the higher-order harmonic generation of the general limited diffraction m-th-order Bessel beam. The analysis is based on successive approximations of the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation. Asymptotic expansions are presented for higher-order harmonic Bessel beams in near and far fields. The validity of asymptotic approximation is also analyzed. The higher-order harmonic of the Bessel beam with the lowest zero-order is taken as a special example. Project supported by the National Natural Science Foundation of China (Grant Nos. 11074038 and 11374051).
Social stigma and compounded losses: quality-of-life issues for multiple-birth families.
Ellison, Marcia A; Hall, Janet E
2003-08-01
To determine the quality-of-life domains most impacted by multiple births. Focus groups, qualitative research. Human volunteers in a medical research environment.Forty-three mothers, 29 raising multiple-birth children, 13 raising singletons, identified from random and convenience samples. None. Maternal self-reports of the psychosocial sequelae of multiple or singleton births, based on qualitative data analysis of transcribed group discussions. The quality-of-life domains that were most impacted by raising multiple birth children were social stigma, pregnancy loss, marital satisfaction, children's health, unmet family needs, parenting stress, maternal depression, and the infertility experience. Qualitative methods identified two novel quality-of-life domains in iatrogenic multiple birth families: social stigma and compounded losses. An unexpected finding was the potential for increased marital solidification as parents coped with the inordinate stresses of multiple births. As anticipated, children's health, unmet family needs, maternal depression, and parental stress were key areas of concern. In addition, the infertility experience had a lasting impact. These findings are significant, given that at least 38% of all assisted conceptions result in a multiple birth. This study lays the groundwork for further research on the impact of iatrogenic multiple births.
Variations in multiple birth rates and impact on perinatal outcomes in Europe
Heino, A.; Gissler, M.; Hindori-Mohangoo, A.D.; Blondel, B.; Klungsøyr, K.; Verdenik, I.; Mierzejewska, E.; Velebil, P.; Sól Ólafsdóttir, H.; Macfarlane, A.; Zeitlin, J.; et al.
2016-01-01
Objective. Infants from multiple pregnancies have higher rates of preterm birth, stillbirth and neonatal death and differences in multiple birth rates (MBR) exist between countries. We aimed to describe differences in MBR in Europe and to investigate the impact of these differences on adverse
Protein scaffolds and higher-order complexes in synthetic biology
den Hamer, A.; Rosier, B.J.H.M.; Brunsveld, L.; de Greef, T.F.A.; Ryadnov, M.; Brunsveld, L.; Suga, H.
2017-01-01
Interactions between proteins control molecular functions such as signalling or metabolic activity. Assembly of proteins via scaffold proteins or in higher-order complexes is a key regulatory mechanism. Understanding and functionally applying this concept requires the construction, study, and
Generating superpositions of higher order bessel beams [Conference paper
CSIR Research Space (South Africa)
Vasilyeu, R
2009-10-01
Full Text Available An experimental setup to generate a superposition of higher-order Bessel beams by means of a spatial light modulator and ring aperture is presented. The experimentally produced fields are in good agreement with those calculated theoretically....
Higher-order curvature terms and extended inflation
International Nuclear Information System (INIS)
Wang Yun
1990-01-01
We consider higher-order curvature terms in context of the Brans-Dicke theory of gravity, and investigate the effects of these terms on extended inflationary theories. We find that the higher-order curvature terms tend to speed up inflation, although the original extended-inflation solutions are stable when these terms are small. Analytical solutions are found for two extreme cases: when the higher-order curvature terms are small, and when they dominate. A conformal transformation is employed in solving the latter case, and some of the subtleties in this technique are discussed. We note that percolation is less likely to occur when the higher-order curvature terms are present. An upper bound on α is expected if we are to avoid excessive and inadequate percolation of true-vacuum bubbles
Unambiguous formalism for higher order Lagrangian field theories
International Nuclear Information System (INIS)
Campos, Cedric M; De Leon, Manuel; De Diego, David MartIn; Vankerschaver, Joris
2009-01-01
The aim of this paper is to propose an unambiguous intrinsic formalism for higher order field theories which avoids the arbitrariness in the generalization of the conventional description of field theories, and implies the existence of different Cartan forms and Legendre transformations. We propose a differential-geometric setting for the dynamics of a higher order field theory, based on the Skinner and Rusk formalism for mechanics. This approach incorporates aspects of both the Lagrangian and the Hamiltonian description, since the field equations are formulated using the Lagrangian on a higher order jet bundle and the canonical multisymplectic form on its affine dual. As both of these objects are uniquely defined, the Skinner-Rusk approach has the advantage that it does not suffer from the arbitrariness in conventional descriptions. The result is that we obtain a unique and global intrinsic version of the Euler-Lagrange equations for higher order field theories. Several examples illustrate our construction.
Higher-order RANS turbulence models for separated flows
National Aeronautics and Space Administration — Higher-order Reynolds-averaged Navier-Stokes (RANS) models are developed to overcome the shortcomings of second-moment RANS models in predicting separated flows....
A simplified parsimonious higher order multivariate Markov chain model
Wang, Chao; Yang, Chuan-sheng
2017-09-01
In this paper, a simplified parsimonious higher-order multivariate Markov chain model (SPHOMMCM) is presented. Moreover, parameter estimation method of TPHOMMCM is give. Numerical experiments shows the effectiveness of TPHOMMCM.
A tridiagonal parsimonious higher order multivariate Markov chain model
Wang, Chao; Yang, Chuan-sheng
2017-09-01
In this paper, we present a tridiagonal parsimonious higher-order multivariate Markov chain model (TPHOMMCM). Moreover, estimation method of the parameters in TPHOMMCM is give. Numerical experiments illustrate the effectiveness of TPHOMMCM.
Application of Mass Lumped Higher Order Finite Elements
International Nuclear Information System (INIS)
J. Chen, H.R. Strauss, S.C. Jardin, W. Park, L.E. Sugiyama, G. Fu, J. Breslau
2005-01-01
There are many interesting phenomena in extended-MHD such as anisotropic transport, mhd, 2-fluid effects stellarator and hot particles. Any one of them challenges numerical analysts, and researchers are seeking for higher order methods, such as higher order finite difference, higher order finite elements and hp/spectral elements. It is true that these methods give more accurate solution than their linear counterparts. However, numerically they are prohibitively expensive. Here we give a successful solution of this conflict by applying mass lumped higher order finite elements. This type of elements not only keep second/third order accuracy but also scale closely to linear elements by doing mass lumping. This is especially true for second order lump elements. Full M3D and anisotropic transport models are studied
The role of formative feedback in promoting higher order thinking ...
African Journals Online (AJOL)
The role of formative feedback in promoting higher order thinking skills in ... activities, task characteristics, validating students' thinking, and providing feedback. ... Keywords: classroom environment, formative assessment, formative feedback, ...
Asymptotic Expansions for Higher-Order Scalar Difference Equations
Directory of Open Access Journals (Sweden)
Ravi P. Agarwal
2007-04-01
Full Text Available We give an asymptotic expansion of the solutions of higher-order PoincarÃƒÂ© difference equation in terms of the characteristic solutions of the limiting equation. As a consequence, we obtain an asymptotic description of the solutions approaching a hyperbolic equilibrium of a higher-order nonlinear difference equation with sufficiently smooth nonlinearity. The proof is based on the inversion formula for the z -transform and the residue theorem.
Asymptotic Expansions for Higher-Order Scalar Difference Equations
Directory of Open Access Journals (Sweden)
Pituk Mihály
2007-01-01
Full Text Available We give an asymptotic expansion of the solutions of higher-order Poincaré difference equation in terms of the characteristic solutions of the limiting equation. As a consequence, we obtain an asymptotic description of the solutions approaching a hyperbolic equilibrium of a higher-order nonlinear difference equation with sufficiently smooth nonlinearity. The proof is based on the inversion formula for the z -transform and the residue theorem.
Higher order aberrations of the eye: Part one
Directory of Open Access Journals (Sweden)
Marsha Oberholzer
2016-06-01
Full Text Available This article is the first in a series of two articles that provide a comprehensive literature review of higher order aberrations (HOAs of the eye. The present article mainly explains the general principles of such HOAs as well as HOAs of importance, and the measuring apparatus used to measure HOAs of the eye. The second article in the series discusses factors contributing to variable results in measurements of HOAs of the eye. Keywords: Higher order aberrations; wavefront aberrations; aberrometer
All-fiber Raman Probe using Higher Order Modes
DEFF Research Database (Denmark)
Larsen, Stine Højer Møller; Rishøj, Lars Søgaard; Rottwitt, Karsten
2013-01-01
We demonstrate the first all-fiber Raman probe utilizing higher order modes for the excitation. The spectrum of cyclohexane is measured using both the fundamental mode as well as in-fiber-generated Bessel-like modes.......We demonstrate the first all-fiber Raman probe utilizing higher order modes for the excitation. The spectrum of cyclohexane is measured using both the fundamental mode as well as in-fiber-generated Bessel-like modes....
Linear matrix differential equations of higher-order and applications
Directory of Open Access Journals (Sweden)
Mustapha Rachidi
2008-07-01
Full Text Available In this article, we study linear differential equations of higher-order whose coefficients are square matrices. The combinatorial method for computing the matrix powers and exponential is adopted. New formulas representing auxiliary results are obtained. This allows us to prove properties of a large class of linear matrix differential equations of higher-order, in particular results of Apostol and Kolodner are recovered. Also illustrative examples and applications are presented.
Interactions, strings and isotopies in higher order anisotropic superspaces
Vacaru, Sergiu Ion
2001-01-01
The monograph summarizes the author's results on the geometry of anholonomic and locally anisotropic interactions, published in J. Math. Phys., Nucl. Phys. B, Ann. Phys. (NY), JHEP, Rep. Math. Phys., Int. J. Theor. Phys. and in some former Soviet Union and Romanian scientific journals. The main subjects are in the theory of field interactions, strings and diffusion processes on spaces, superspaces and isospaces with higher order anisotropy and inhomogeneity. The approach proceeds by developing the concept of higher order anisotropic (super)space which unifies the logical and manthematical aspects of modern Kaluza--Klein theories and generalized Lagrange and Finsler geometry and leads to modeling of physical processes on higher order fiber (super)bundles provided with nonlinear and distinguished connections and metric structures. This book can be also considered as a pedagogical survey on the mentioned subjects.
Higher-order modulation instability in nonlinear fiber optics.
Erkintalo, Miro; Hammani, Kamal; Kibler, Bertrand; Finot, Christophe; Akhmediev, Nail; Dudley, John M; Genty, Goëry
2011-12-16
We report theoretical, numerical, and experimental studies of higher-order modulation instability in the focusing nonlinear Schrödinger equation. This higher-order instability arises from the nonlinear superposition of elementary instabilities, associated with initial single breather evolution followed by a regime of complex, yet deterministic, pulse splitting. We analytically describe the process using the Darboux transformation and compare with experiments in optical fiber. We show how a suitably low frequency modulation on a continuous wave field induces higher-order modulation instability splitting with the pulse characteristics at different phases of evolution related by a simple scaling relationship. We anticipate that similar processes are likely to be observed in many other systems including plasmas, Bose-Einstein condensates, and deep water waves. © 2011 American Physical Society
Higher Order Lagrange Finite Elements In M3D
International Nuclear Information System (INIS)
Chen, J.; Strauss, H.R.; Jardin, S.C.; Park, W.; Sugiyama, L.E.; Fu, G.; Breslau, J.
2004-01-01
The M3D code has been using linear finite elements to represent multilevel MHD on 2-D poloidal planes. Triangular higher order elements, up to third order, are constructed here in order to provide M3D the capability to solve highly anisotropic transport problems. It is found that higher order elements are essential to resolve the thin transition layer characteristic of the anisotropic transport equation, particularly when the strong anisotropic direction is not aligned with one of the Cartesian coordinates. The transition layer is measured by the profile width, which is zero for infinite anisotropy. It is shown that only higher order schemes have the ability to make this layer converge towards zero when the anisotropy gets stronger and stronger. Two cases are considered. One has the strong transport direction partially aligned with one of the element edges, the other doesn't have any alignment. Both cases have the strong transport direction misaligned with the grid line by some angles
Practical implementation of a higher order transverse leakage approximation
International Nuclear Information System (INIS)
Prinsloo, Rian H.; Tomašević
2011-01-01
Transverse integrated nodal diffusion methods currently represent the standard in full core neutronic simulation. The primary shortcoming in this approach, be it via the Analytic Nodal Method or Nodal Expansion Method, is the utilization of the quadratic transverse leakage approximation. This approach, although proven to work well for typical LWR problems, is not consistent with the formulation of nodal methods and can cause accuracy and convergence problems. In this work an improved, consistent quadratic leakage approximation is formulated, which derives from the class of higher order nodal methods developed some years ago. In this new approach, only information relevant to describing the transverse leak- age terms in the zero-order nodal equations are obtained from the higher order formalism. The method yields accuracy comparable to full higher order methods, but does not suffer from the same computational burden which these methods typically incur. (author)
Higher order multipoles and splines in plasma simulations
International Nuclear Information System (INIS)
Okuda, H.; Cheng, C.Z.
1978-01-01
The reduction of spatial grid effects in plasma simulations has been studied numerically using higher order multipole expansions and the spline method in one dimension. It is found that, while keeping the higher order moments such as quadrupole and octopole moments substantially reduces the grid effects, quadratic and cubic splines in general have better stability properties for numerical plasma simulations when the Debye length is much smaller than the grid size. In particular the spline method may be useful in three-dimensional simulations for plasma confinement where the grid size in the axial direction is much greater than the Debye length. (Auth.)
Higher-order multipoles and splines in plasma simulations
International Nuclear Information System (INIS)
Okuda, H.; Cheng, C.Z.
1977-12-01
Reduction of spatial grid effects in plasma simulations has been studied numerically using higher order multipole expansions and spline method in one dimension. It is found that, while keeping the higher order moments such as quadrupole and octopole moments substantially reduces the grid effects, quadratic and cubic splines in general have better stability properties for numerical plasma simulations when the Debye length is much smaller than the grid size. In particular, spline method may be useful in three dimensional simulations for plasma confinement where the grid size in the axial direction is much greater than the Debye length
Multilevel Fast Multipole Method for Higher Order Discretizations
DEFF Research Database (Denmark)
Borries, Oscar Peter; Meincke, Peter; Jorgensen, Erik
2014-01-01
The multi-level fast multipole method (MLFMM) for a higher order (HO) discretization is demonstrated on high-frequency (HF) problems, illustrating for the first time how an efficient MLFMM for HO can be achieved even for very large groups. Applying several novel ideas, beneficial to both lower...... order and higher order discretizations, results from a low-memory, high-speed MLFMM implementation of a HO hierarchical discretization are shown. These results challenge the general view that the benefits of HO and HF-MLFMM cannot be combined....
The Cauchy problem for higher order abstract differential equations
Xiao, Ti-Jun
1998-01-01
This monograph is the first systematic exposition of the theory of the Cauchy problem for higher order abstract linear differential equations, which covers all the main aspects of the developed theory. The main results are complete with detailed proofs and established recently, containing the corresponding theorems for first and incomplete second order cases and therefore for operator semigroups and cosine functions. They will find applications in many fields. The special power of treating the higher order problems directly is demonstrated, as well as that of the vector-valued Laplace transforms in dealing with operator differential equations and operator families. The reader is expected to have a knowledge of complex and functional analysis.
The Role of Formative Feedback in Promoting Higher Order ...
African Journals Online (AJOL)
DrNneka
An International Multi-disciplinary Journal, Ethiopia. AFRREV ... make contribution to this research gap by proposing a theoretical feedback model that can promote higher order thinking skills in the classroom. The proposed ..... process; students provided with tasks that are novel, complex, creative, and non- algorithmic ...
Developing Higher-Order Thinking Skills through WebQuests
Polly, Drew; Ausband, Leigh
2009-01-01
In this study, 32 teachers participated in a year-long professional development project related to technology integration in which they designed and implemented a WebQuest. This paper describes the extent to which higher-order thinking skills (HOTS) and levels of technology implementation (LoTI) occur in the WebQuests that participants designed.…
Hamiltonian formulation of theory with higher order derivatives
International Nuclear Information System (INIS)
Gitman, D.M.; Lyakhovich, S.L.; Tyutin, I.V.
1983-01-01
A method of ''hamiltonization'' of a special theory with higher order derivatives is described. In a nonspecial case the result coincides with the known Ostrogradsky formulation. It is shown that in the nonspecial theory the lagrange equations of motion are reduced to the normal form
Numerical methods of higher order of accuracy for incompressible flows
Czech Academy of Sciences Publication Activity Database
Kozel, K.; Louda, Petr; Příhoda, Jaromír
2010-01-01
Roč. 80, č. 8 (2010), s. 1734-1745 ISSN 0378-4754 Institutional research plan: CEZ:AV0Z20760514 Keywords : higher order methods * upwind methods * backward-facing step Subject RIV: BK - Fluid Dynamics Impact factor: 0.812, year: 2010
First Measurements of Higher Order Optics Parameters in the LHC
Vanbavinckhove, G; Bartolini, R; Calaga, R; Giovannozzi, M; Maclean, E H; Miyamoto, R; Schmidt, F; Tomas, R
2011-01-01
Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these pa- rameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed sim- ulations are compared to the measurements together with discussions on the measurement limitations.
Time-Discrete Higher-Order ALE Formulations: Stability
Bonito, Andrea; Kyza, Irene; Nochetto, Ricardo H.
2013-01-01
on the stability of the PDE but may influence that of a discrete scheme. We examine this critical issue for higher-order time stepping without space discretization. We propose time-discrete discontinuous Galerkin (dG) numerical schemes of any order for a time
Meta-Logical Reasoning in Higher-Order Logic
DEFF Research Database (Denmark)
Villadsen, Jørgen; Schlichtkrull, Anders; Hess, Andreas Viktor
The semantics of first-order logic (FOL) can be described in the meta-language of higher-order logic (HOL). Using HOL one can prove key properties of FOL such as soundness and completeness. Furthermore, one can prove sentences in FOL valid using the formalized FOL semantics. To aid...
Decidable Fragments of a Higher Order Calculus with Locations
DEFF Research Database (Denmark)
Bundgaard, Mikkel; Godskesen, Jens Christian; Huttel, Hans
2009-01-01
Homer is a higher order process calculus with locations. In this paper we study Homer in the setting of the semantic finite control property, which is a finite reachability criterion that implies decidability of barbed bisimilarity. We show that strong and weak barbed bisimilarity are undecidable...
Computer-Mediated Assessment of Higher-Order Thinking Development
Tilchin, Oleg; Raiyn, Jamal
2015-01-01
Solving complicated problems in a contemporary knowledge-based society requires higher-order thinking (HOT). The most productive way to encourage development of HOT in students is through use of the Problem-based Learning (PBL) model. This model organizes learning by solving corresponding problems relative to study courses. Students are directed…
Higher-order chaotic oscillator using active bessel filter
DEFF Research Database (Denmark)
Lindberg, Erik; Mykolaitis, Gytis; Bumelien, Skaidra
2010-01-01
A higher-order oscillator, including a nonlinear unit and an 8th-order low-pass active Bessel filter is described. The Bessel unit plays the role of "three-in-one": a delay line, an amplifier and a filter. Results of hardware experiments and numerical simulation are presented. Depending...
Constrained variational calculus for higher order classical field theories
Energy Technology Data Exchange (ETDEWEB)
Campos, Cedric M; De Leon, Manuel; De Diego, David MartIn, E-mail: cedricmc@icmat.e, E-mail: mdeleon@icmat.e, E-mail: david.martin@icmat.e [Instituto de Ciencias Matematicas, CSIC-UAM-UC3M-UCM, Serrano 123, 28006 Madrid (Spain)
2010-11-12
We develop an intrinsic geometrical setting for higher order constrained field theories. As a main tool we use an appropriate generalization of the classical Skinner-Rusk formalism. Some examples of applications are studied, in particular to the geometrical description of optimal control theory for partial differential equations.
Constrained variational calculus for higher order classical field theories
International Nuclear Information System (INIS)
Campos, Cedric M; De Leon, Manuel; De Diego, David MartIn
2010-01-01
We develop an intrinsic geometrical setting for higher order constrained field theories. As a main tool we use an appropriate generalization of the classical Skinner-Rusk formalism. Some examples of applications are studied, in particular to the geometrical description of optimal control theory for partial differential equations.
Higher-Order Integral Equation Methods in Computational Electromagnetics
DEFF Research Database (Denmark)
Jørgensen, Erik; Meincke, Peter
Higher-order integral equation methods have been investigated. The study has focused on improving the accuracy and efficiency of the Method of Moments (MoM) applied to electromagnetic problems. A new set of hierarchical Legendre basis functions of arbitrary order is developed. The new basis...
Higher-Order Separation Logic in Isabelle/HOLCF
DEFF Research Database (Denmark)
Varming, Carsten; Birkedal, Lars
2008-01-01
We formalize higher-order separation logic for a first-order imperative language with procedures and local variables in Isabelle/HOLCF. The assertion language is modeled in such a way that one may use any theory defined in Isabelle/HOLCF to construct assertions, e.g., primitive recursion, least o...
Order-sorted Algebraic Specifications with Higher-order Functions
DEFF Research Database (Denmark)
Haxthausen, Anne Elisabeth
1995-01-01
This paper gives a proposal for how order-sorted algebraic specification languages can be extended with higher-order functions. The approach taken is a generalisation to the order-sorted case of an approach given by Mller, Tarlecki and Wirsing for the many-sorted case. The main idea in the proposal...
Enhancing Higher Order Thinking Skills through Clinical Simulation
Varutharaju, Elengovan; Ratnavadivel, Nagendralingan
2014-01-01
Purpose: The study aimed to explore, describe and analyse the design and implementation of clinical simulation as a pedagogical tool in bridging the deficiency of higher order thinking skills among para-medical students, and to make recommendations on incorporating clinical simulation as a pedagogical tool to enhance thinking skills and align the…
Improved Multilevel Fast Multipole Method for Higher-Order discretizations
DEFF Research Database (Denmark)
Borries, Oscar Peter; Meincke, Peter; Jorgensen, Erik
2014-01-01
The Multilevel Fast Multipole Method (MLFMM) allows for a reduced computational complexity when solving electromagnetic scattering problems. Combining this with the reduced number of unknowns provided by Higher-Order discretizations has proven to be a difficult task, with the general conclusion b...
Higher-Order Hierarchical Legendre Basis Functions in Applications
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter
2007-01-01
The higher-order hierarchical Legendre basis functions have been developed for eﬀective solution of integral equations with the method of moments. They are derived from orthogonal Legendre polynomials modiﬁed to enforce normal continuity between neighboring mesh elements, while preserving a high...
Treyvaud, Karli; Aldana, Andrea C; Scratch, Shannon E; Ure, Alexandra M; Pace, Carmen C; Doyle, Lex W; Anderson, Peter J
2016-09-01
Psychological distress has been reported by mothers of infants born very preterm (VPT) and by mothers of multiples (twins and triplets). This study examined the influence of i) multiple birth and ii) bereavement associated with a multifetal pregnancy, on mental health, parenting stress and family functioning for mothers of children born VPT across early childhood. Participants were 162 mothers of 194 infants (129 singletons, 65 multiples) born at family functioning were assessed using the Parenting Stress Index and Family Assessment Device. Maternal mental health, stress and family functioning were similar in mothers of VPT singletons and multiples. However compared with mothers who had not experienced bereavement, mothers who had were 3.6 times [95% confidence interval (95% CI) 1.05, 12.5] more likely to report elevated anxiety symptoms and 3.6 times [95% CI 1.05, 12.3] more likely to report elevated depressive symptoms when their VPT child was seven years old. The results of this study highlight the need for monitoring and offering ongoing support to bereaved mothers with surviving VPT children. However, within the context of VPT birth, multiple birth does not increase the risk for maternal psychological distress in early childhood. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Higher order QCD corrections in small x physics
International Nuclear Information System (INIS)
Chachamis, G.
2006-11-01
We study higher order QCD corrections in small x Physics. The numerical implementation of the full NLO photon impact factor is the remaining necessary piece for the testing of the NLO BFKL resummation against data from physical processes, such as γ * γ * collisions. We perform the numerical integration over phase space for the virtual corrections to the NLO photon impact factor. This, along with the previously calculated real corrections, makes feasible in the near future first estimates for the γ*γ* total cross section, since the convolution of the full impact factor with the NLO BFKL gluon Green's function is now straightforward. The NLO corrections for the photon impact factor are sizeable and negative. In the second part of this thesis, we estimate higher order correction to the BK equation. We are mainly interested in whether partonic saturation delays or not in rapidity when going beyond the leading order. In our investigation, we use the so called 'rapidity veto' which forbid two emissions to be very close in rapidity, to 'switch on' higher order corrections to the BK equation. From analytic and numerical analysis, we conclude that indeed saturation does delay in rapidity when higher order corrections are taken into account. In the last part, we investigate higher order QCD corrections as additional corrections to the Electroweak (EW) sector. The question of whether BFKL corrections are of any importance in the Regge limit for the EW sector seems natural; although they arise in higher loop level, the accumulation of logarithms in energy s at high energies, cannot be dismissed without an investigation. We focus on the process γγ→ZZ. We calculate the pQCD corrections in the forward region at leading logarithmic (LL) BFKL accuracy, which are of the order of few percent at the TeV energy scale. (orig.)
Higher order QCD corrections in small x physics
Energy Technology Data Exchange (ETDEWEB)
Chachamis, G.
2006-11-15
We study higher order QCD corrections in small x Physics. The numerical implementation of the full NLO photon impact factor is the remaining necessary piece for the testing of the NLO BFKL resummation against data from physical processes, such as {gamma}{sup *}{gamma}{sup *} collisions. We perform the numerical integration over phase space for the virtual corrections to the NLO photon impact factor. This, along with the previously calculated real corrections, makes feasible in the near future first estimates for the {gamma}*{gamma}* total cross section, since the convolution of the full impact factor with the NLO BFKL gluon Green's function is now straightforward. The NLO corrections for the photon impact factor are sizeable and negative. In the second part of this thesis, we estimate higher order correction to the BK equation. We are mainly interested in whether partonic saturation delays or not in rapidity when going beyond the leading order. In our investigation, we use the so called 'rapidity veto' which forbid two emissions to be very close in rapidity, to 'switch on' higher order corrections to the BK equation. From analytic and numerical analysis, we conclude that indeed saturation does delay in rapidity when higher order corrections are taken into account. In the last part, we investigate higher order QCD corrections as additional corrections to the Electroweak (EW) sector. The question of whether BFKL corrections are of any importance in the Regge limit for the EW sector seems natural; although they arise in higher loop level, the accumulation of logarithms in energy s at high energies, cannot be dismissed without an investigation. We focus on the process {gamma}{gamma}{yields}ZZ. We calculate the pQCD corrections in the forward region at leading logarithmic (LL) BFKL accuracy, which are of the order of few percent at the TeV energy scale. (orig.)
Self-similarity of higher-order moving averages
Arianos, Sergio; Carbone, Anna; Türk, Christian
2011-10-01
In this work, higher-order moving average polynomials are defined by straightforward generalization of the standard moving average. The self-similarity of the polynomials is analyzed for fractional Brownian series and quantified in terms of the Hurst exponent H by using the detrending moving average method. We prove that the exponent H of the fractional Brownian series and of the detrending moving average variance asymptotically agree for the first-order polynomial. Such asymptotic values are compared with the results obtained by the simulations. The higher-order polynomials correspond to trend estimates at shorter time scales as the degree of the polynomial increases. Importantly, the increase of polynomial degree does not require to change the moving average window. Thus trends at different time scales can be obtained on data sets with the same size. These polynomials could be interesting for those applications relying on trend estimates over different time horizons (financial markets) or on filtering at different frequencies (image analysis).
Comparison Criteria for Nonlinear Functional Dynamic Equations of Higher Order
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Taher S. Hassan
2016-01-01
Full Text Available We will consider the higher order functional dynamic equations with mixed nonlinearities of the form xnt+∑j=0Npjtϕγjxφjt=0, on an above-unbounded time scale T, where n≥2, xi(t≔ri(tϕαixi-1Δ(t, i=1,…,n-1, with x0=x, ϕβ(u≔uβsgnu, and α[i,j]≔αi⋯αj. The function φi:T→T is a rd-continuous function such that limt→∞φi(t=∞ for j=0,1,…,N. The results extend and improve some known results in the literature on higher order nonlinear dynamic equations.
Higher Order Differential Attack on 6-Round MISTY1
Tsunoo, Yukiyasu; Saito, Teruo; Nakashima, Hiroki; Shigeri, Maki
MISTY1 is a 64-bit block cipher that has provable security against differential and linear cryptanalysis. MISTY1 is one of the algorithms selected in the European NESSIE project, and it has been recommended for Japanese e-Government ciphers by the CRYPTREC project. This paper reports a previously unknown higher order differential characteristic of 4-round MISTY1 with the FL functions. It also shows that a higher order differential attack that utilizes this newly discovered characteristic is successful against 6-round MISTY1 with the FL functions. This attack can recover a partial subkey with a data complexity of 253.7 and a computational complexity of 264.4, which is better than any previous cryptanalysis of MISTY1.
Higher-order risk preferences in social settings.
Heinrich, Timo; Mayrhofer, Thomas
2018-01-01
We study prudence and temperance (next to risk aversion) in social settings. Previous experimental studies have shown that these higher-order risk preferences affect the choices of individuals deciding privately on lotteries that only affect their own payoff. Yet, many risky and financially relevant decisions are made in the social settings of households or organizations. We elicit higher-order risk preferences of individuals and systematically vary how an individual's decision is made (alone or while communicating with a partner) and who is affected by the decision (only the individual or the partner as well). In doing so, we can isolate the effects of other-regarding concerns and communication on choices. Our results reveal that the majority of choices are risk averse, prudent, and temperate across social settings. We also observe that individuals are influenced significantly by the preferences of a partner when they are able to communicate and choices are payoff-relevant for both of them.
Higher-order geodesic deviations applied to the Kerr metric
Colistete, R J; Kerner, R
2002-01-01
Starting with an exact and simple geodesic, we generate approximate geodesics by summing up higher-order geodesic deviations within a general relativistic setting, without using Newtonian and post-Newtonian approximations. We apply this method to the problem of closed orbital motion of test particles in the Kerr metric spacetime. With a simple circular orbit in the equatorial plane taken as the initial geodesic, we obtain finite eccentricity orbits in the form of Taylor series with the eccentricity playing the role of a small parameter. The explicit expressions of these higher-order geodesic deviations are derived using successive systems of linear equations with constant coefficients, whose solutions are of harmonic oscillator type. This scheme gives best results when applied to orbits with low eccentricities, but with arbitrary possible values of (GM/Rc sup 2).
An Algorithm for Higher Order Hopf Normal Forms
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A.Y.T. Leung
1995-01-01
Full Text Available Normal form theory is important for studying the qualitative behavior of nonlinear oscillators. In some cases, higher order normal forms are required to understand the dynamic behavior near an equilibrium or a periodic orbit. However, the computation of high-order normal forms is usually quite complicated. This article provides an explicit formula for the normalization of nonlinear differential equations. The higher order normal form is given explicitly. Illustrative examples include a cubic system, a quadratic system and a Duffing–Van der Pol system. We use exact arithmetic and find that the undamped Duffing equation can be represented by an exact polynomial differential amplitude equation in a finite number of terms.
The higher order flux mapping method in large size PHWRs
International Nuclear Information System (INIS)
Kulkarni, A.K.; Balaraman, V.; Purandare, H.D.
1997-01-01
A new higher order method is proposed for obtaining flux map using single set of expansion mode. In this procedure, one can make use of the difference between predicted value of detector reading and their actual values for determining the strength of local fluxes around detector site. The local fluxes are arising due to constant perturbation changes (both extrinsic and intrinsic) taking place in the reactor. (author)
Practical Programming with Higher-Order Encodings and Dependent Types
DEFF Research Database (Denmark)
Poswolsky, Adam; Schürmann, Carsten
2008-01-01
, tedious, and error-prone. In this paper, we describe the underlying calculus of Delphin. Delphin is a fully implemented functional-programming language supporting reasoning over higher-order encodings and dependent types, while maintaining the benefits of HOAS. More specifically, just as representations...... for instantiation from those that will remain uninstantiated, utilizing a variation of Miller and Tiu’s ∇-quantifier [1]....
Modeling Human Behaviour with Higher Order Logic: Insider Threats
DEFF Research Database (Denmark)
Boender, Jaap; Ivanova, Marieta Georgieva; Kammuller, Florian
2014-01-01
it to the sociological process of logical explanation. As a case study on modeling human behaviour, we present the modeling and analysis of insider threats as a Higher Order Logic theory in Isabelle/HOL. We show how each of the three step process of sociological explanation can be seen in our modeling of insider’s state......, its context within an organisation and the effects on security as outcomes of a theorem proving analysis....
Higher order Bose-Einstein correlations in identical particle production
International Nuclear Information System (INIS)
Biyajima, M.
1990-01-01
A diagram technique to calculate the higher order Bose-Einstein correlations is formulated. This technique is applied to derive explicit expressions for the n-pion correlation functions for n = 2, 3, 4, and 5, and numerical predictions are given. In a comparison with the AFS and NA23 data on two-pion and three-pion Bose-Einstein correlations good agreement is obtained. 21 refs., 5 figs. (Authors)
Tehran Survey of Potential Risk Factors for Multiple Births
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Reza Omani Samani
2017-09-01
Full Text Available Background The multiple pregnancy incidence is increasing worldwide. This increased incidence is concerning to the health care system. This study aims to determine the frequency of multiple pregnancy and identify factors that affect this frequency in Tehran, Iran. Materials and Methods This cross-sectional study included 5170 mothers in labor between July 6-21, 2015 from 103 hospitals with Obstetrics and Gynecology Wards. The questionnaire used in this study consisted of five parts: demographic characteristics; information related to pregnancy; information related to the infant; information regarding the multiple pregnancy; and information associated with infertility. We recruited 103 trained midwives to collect data related to the questionnaire from eligible participants through an interview and medical records review. Frequencies and odds ratios (OR for the association between multiple pregnancy and the selected characteristics (maternal age, economic status, history of multiple pregnancy in first-degree relatives, and reproductive history were computed by multiple logistic regression. Stata software, version 13 (Stata Corp, College Station, TX, USA was used for all statistical analyses. Results Multiple pregnancy had a prevalence of 1.48% [95% confidence interval (CI: 1.19-1.85]. After controlling for confounding variables, we observed a significant association between frequency of multiple pregnancy and mother’s age (OR=1.04, 95% CI: 1.001-1.09, P=0.044, assisted reproductive technique (ART, OR=6.11, 95% CI: 1.7- 21.97, P=0.006, and history of multiple pregnancy in the mother’s family (OR=5.49, 95% CI: 3.55-9.93, P=0.001. Conclusion The frequency of multiple pregnancy approximated results reported in previous studies in Iran. Based on the results, we observed significantly greater frequency of multiple pregnancy in older women, those with a history of ART, and a history of multiple pregnancy in the mother’s family compared to the other
Higher-Order Finite Element Solutions of Option Prices
DEFF Research Database (Denmark)
Raahauge, Peter
2004-01-01
Kinks and jumps in the payoff function of option contracts prevent an effectiveimplementation of higher-order numerical approximation methods. Moreover, thederivatives (the greeks) are not easily determined around such singularities, even withstandard lower-order methods. This paper suggests...... for prices as well as for first and second order derivatives(delta and gamma). Unlike similar studies, numerical approximation errors aremeasured both as weighted averages and in the supnorm over a state space includingtime-to-maturities down to a split second.KEYWORDS: Numerical option pricing, Transformed...
Higher-order Brunnian structures and possible physical realizations
DEFF Research Database (Denmark)
A. Baas, Nils; V. Fedorov, D.; S. Jensen, A.
2014-01-01
We consider few-body bound state systems and provide precise definitions of Borromean and Brunnian systems. The initial concepts are more than a hundred years old and originated in mathematical knot-theory as purely geometric considerations. About thirty years ago they were generalized and applied...... to the binding of systems in nature. It now appears that recent generalization to higher order Brunnian structures may potentially be realized as laboratory made or naturally occurring systems. With the binding energy as measure, we discuss possibilities of physical realization in nuclei, cold atoms...
Development of higher order mode couplers at Cornell
International Nuclear Information System (INIS)
Amato, J.C.
1988-01-01
Higher order mode (HOM) couplers are integral parts of a superconducting accelerator cavity. The damping which the couplers must provide is dictated by the frequency and shunt impedance of the cavity modes as well as by the stability requirements of the accelerator incorporating the cavities. Cornell's 5-cell 1500 MHz elliptical cavity was designed for use in a 50 x 50 GeV electron-positron storage ring with a total beam current of 3.5 mA (CESR-II). HOM couplers for the Cornell cavity were designed and evaluated with this machine in mind. The development of these couplers is described in this paper. 8 references, 8 figures
Theory of a higher-order Sturm-Liouville equation
Kozlov, Vladimir
1997-01-01
This book develops a detailed theory of a generalized Sturm-Liouville Equation, which includes conditions of solvability, classes of uniqueness, positivity properties of solutions and Green's functions, asymptotic properties of solutions at infinity. Of independent interest, the higher-order Sturm-Liouville equation also proved to have important applications to differential equations with operator coefficients and elliptic boundary value problems for domains with non-smooth boundaries. The book addresses graduate students and researchers in ordinary and partial differential equations, and is accessible with a standard undergraduate course in real analysis.
Integrable higher order deformations of Heisenberg supermagnetic model
International Nuclear Information System (INIS)
Guo Jiafeng; Yan Zhaowen; Wang Shikun; Wu Ke; Zhao Weizhong
2009-01-01
The Heisenberg supermagnet model is an integrable supersymmetric system and has a close relationship with the strong electron correlated Hubbard model. In this paper, we investigate the integrable higher order deformations of Heisenberg supermagnet models with two different constraints: (i) S 2 =3S-2I for S is an element of USPL(2/1)/S(U(2)xU(1)) and (ii) S 2 =S for S is an element of USPL(2/1)/S(L(1/1)xU(1)). In terms of the gauge transformation, their corresponding gauge equivalent counterparts are derived.
Oscillation of solutions of some higher order linear differential equations
Directory of Open Access Journals (Sweden)
Hong-Yan Xu
2009-11-01
Full Text Available In this paper, we deal with the order of growth and the hyper order of solutions of higher order linear differential equations $$f^{(k}+B_{k-1}f^{(k-1}+\\cdots+B_1f'+B_0f=F$$ where $B_j(z (j=0,1,\\ldots,k-1$ and $F$ are entire functions or polynomials. Some results are obtained which improve and extend previous results given by Z.-X. Chen, J. Wang, T.-B. Cao and C.-H. Li.
Higher order temporal finite element methods through mixed formalisms.
Kim, Jinkyu
2014-01-01
The extended framework of Hamilton's principle and the mixed convolved action principle provide new rigorous weak variational formalism for a broad range of initial boundary value problems in mathematical physics and mechanics. In this paper, their potential when adopting temporally higher order approximations is investigated. The classical single-degree-of-freedom dynamical systems are primarily considered to validate and to investigate the performance of the numerical algorithms developed from both formulations. For the undamped system, all the algorithms are symplectic and unconditionally stable with respect to the time step. For the damped system, they are shown to be accurate with good convergence characteristics.
Programming real-time executives in higher order language
Foudriat, E. C.
1982-01-01
Methods by which real-time executive programs can be implemented in a higher order language are discussed, using HAL/S and Path Pascal languages as program examples. Techniques are presented by which noncyclic tasks can readily be incorporated into the executive system. Situations are shown where the executive system can fail to meet its task scheduling and yet be able to recover either by rephasing the clock or stacking the information for later processing. The concept of deadline processing is shown to enable more effective mixing of time and information synchronized systems.
Squeezing of higher order Hermite-Gauss modes
DEFF Research Database (Denmark)
Lassen, Mikael Østergaard
2008-01-01
The present paper gives an overview of the experimental generation of squeezing in higher order Hermite-Gaussian modes with an optical parametric ampli¯er (OPA). This work was awarded with The European Optical Society (EOS) price 2007. The purpose of the prize is to encourage a European dimension...... in research in pure and applied optics. The EOS prize is awarded based on the selection criteria of high professionalism, academic and technical quality. Following the EOS Prize rules, the conditions for eligibility are that the work was performed in Europe and that it is published under the auspices...
Higher-order dynamical effects in Coulomb dissociation
International Nuclear Information System (INIS)
Esbensen, H.
1994-06-01
We study the effect of higher-order processes in Coulomb dissociation of 11 Li by numerically solving the three-dimensional time-dependent Schroedinger equation for the relative motion of a di-neutron and the 9 Li core. Comparisons are made to first-order perturbation theory and to measurements. The calculated Coulomb reacceleration effects improve the agreement with experiment, but some discrepancy remains. The effects are much smaller in the dissociation of 11 Be, and they decrease with increasing beam energy. (orig.)
Inseparability inequalities for higher order moments for bipartite systems
International Nuclear Information System (INIS)
Agarwal, G S; Biswas, Asoka
2005-01-01
There are several examples of bipartite entangled states of continuous variables for which the existing criteria for entanglement using the inequalities involving the second-order moments are insufficient. We derive new inequalities involving higher order correlation, for testing entanglement in non-Gaussian states. In this context, we study an example of a non-Gaussian state, which is a bipartite entangled state of the form Ψ(x a , x b ) ∝ (αx a + βx b ) e -(x a 2 +x b 2 )/2 . Our results open up an avenue to search for new inequalities to test entanglement in non-Gaussian states
Higher-order thinking in foreign language learning
Bastos, Ascensão; Ramos, Altina
2017-01-01
A project is being conducted in English as a foreign language (EFL), involving eleventh graders in formal and non-formal learning contexts, in a Portuguese high school. The goal of this study is to examine the impact of cognitive tools and higher-order thinking processes on the learning of EFL and achievement of larger processes oriented to action, involving problem solving, decision-making and creation of new products. YouTube videos emerge as cognitive tools in the process. Final results sh...
FitzPatrick, Beverly; Hawboldt, John; Doyle, Daniel; Genge, Terri
2015-02-17
To determine whether national educational outcomes, course objectives, and classroom assessments for 2 therapeutics courses were aligned for curricular content and cognitive processes, and if they included higher-order thinking. Document analysis and student focus groups were used. Outcomes, objectives, and assessment tasks were matched for specific therapeutics content and cognitive processes. Anderson and Krathwohl's Taxonomy was used to define higher-order thinking. Students discussed whether assessments tested objectives and described their thinking when responding to assessments. There were 7 outcomes, 31 objectives, and 412 assessment tasks. The alignment for content and cognitive processes was not satisfactory. Twelve students participated in the focus groups. Students thought more short-answer questions than multiple choice questions matched the objectives for content and required higher-order thinking. The alignment analysis provided data that could be used to reveal and strengthen the enacted curriculum and improve student learning.
Time-Discrete Higher-Order ALE Formulations: Stability
Bonito, Andrea
2013-01-01
Arbitrary Lagrangian Eulerian (ALE) formulations deal with PDEs on deformable domains upon extending the domain velocity from the boundary into the bulk with the purpose of keeping mesh regularity. This arbitrary extension has no effect on the stability of the PDE but may influence that of a discrete scheme. We examine this critical issue for higher-order time stepping without space discretization. We propose time-discrete discontinuous Galerkin (dG) numerical schemes of any order for a time-dependent advection-diffusion-model problem in moving domains, and study their stability properties. The analysis hinges on the validity of the Reynold\\'s identity for dG. Exploiting the variational structure and assuming exact integration, we prove that our conservative and nonconservative dG schemes are equivalent and unconditionally stable. The same results remain true for piecewise polynomial ALE maps of any degree and suitable quadrature that guarantees the validity of the Reynold\\'s identity. This approach generalizes the so-called geometric conservation law to higher-order methods. We also prove that simpler Runge-Kutta-Radau methods of any order are conditionally stable, that is, subject to a mild ALE constraint on the time steps. Numerical experiments corroborate and complement our theoretical results. © 2013 Society for Industrial and Applied Mathematics.
Higher-Order Cyclostationarity Detection for Spectrum Sensing
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Julien Renard
2010-01-01
Full Text Available Recent years have shown a growing interest in the concept of Cognitive Radios (CRs, able to access portions of the electromagnetic spectrum in an opportunistic operating way. Such systems require efficient detectors able to work in low Signal-to-Noise Ratio (SNR environments, with little or no information about the signals they are trying to detect. Energy detectors are widely used to perform such blind detection tasks, but quickly reach the so-called SNR wall below which detection becomes impossible Tandra (2005. Cyclostationarity detectors are an interesting alternative to energy detectors, as they exploit hidden periodicities present in man-made signals, but absent in noise. Such detectors use quadratic transformations of the signals to extract the hidden sine-waves. While most of the literature focuses on the second-order transformations of the signals, we investigate the potential of higher-order transformations of the signals. Using the theory of Higher-Order Cyclostationarity (HOCS, we derive a fourth-order detector that performs similarly to the second-order ones to detect linearly modulated signals, at SNR around 0 dB, which may be used if the signals of interest do not exhibit second-order cyclostationarity. More generally this paper reviews the relevant aspects of the cyclostationary and HOCS theory, and shows their potential for spectrum sensing.
Higher-Order Spectrum in Understanding Nonlinearity in EEG Rhythms
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Cauchy Pradhan
2012-01-01
Full Text Available The fundamental nature of the brain's electrical activities recorded as electroencephalogram (EEG remains unknown. Linear stochastic models and spectral estimates are the most common methods for the analysis of EEG because of their robustness, simplicity of interpretation, and apparent association with rhythmic behavioral patterns in nature. In this paper, we extend the use of higher-order spectrum in order to indicate the hidden characteristics of EEG signals that simply do not arise from random processes. The higher-order spectrum is an extension Fourier spectrum that uses higher moments for spectral estimates. This essentially nullifies all Gaussian random effects, therefore, can reveal non-Gaussian and nonlinear characteristics in the complex patterns of EEG time series. The paper demonstrates the distinguishing features of bispectral analysis for chaotic systems, filtered noises, and normal background EEG activity. The bispectrum analysis detects nonlinear interactions; however, it does not quantify the coupling strength. The squared bicoherence in the nonredundant region has been estimated to demonstrate nonlinear coupling. The bicoherence values are minimal for white Gaussian noises (WGNs and filtered noises. Higher bicoherence values in chaotic time series and normal background EEG activities are indicative of nonlinear coupling in these systems. The paper shows utility of bispectral methods as an analytical tool in understanding neural process underlying human EEG patterns.
Child Maltreatment Among Singletons and Multiple Births in Japan: A Population-Based Study.
Yokoyama, Yoshie; Oda, Terumi; Nagai, Noriyo; Sugimoto, Masako; Mizukami, Kenji
2015-12-01
The occurrence of multiple births has been recognized as a risk factor for child maltreatment. However, few population-based studies have examined the relationship between multiple births and child maltreatment. This study aimed to evaluate the degree of risk of child maltreatment among singletons and multiple births in Japan and to identify factors associated with increased risk. Using population-based data, we analyzed the database of records on child maltreatment and medical checkups for infants aged 1.5 years filed at Nishinomiya City Public Health Center between April 2007 and March 2011. To protect personal information, the data were transferred to anonymized electronic files for analysis. After adjusting by logistic regression for each associated factor and gestation number, multiples themselves were not associated with the risk of child maltreatment. However, compared with singletons, multiples had a significantly higher rate of risk factors for child maltreatment, including low birth weight and neural abnormality. Moreover, compared with mothers of singleton, mothers of twins had a significantly higher rate of poor health, which is a risk factor of child maltreatment. Multiples were not associated with the risk of child maltreatment. However, compared with singletons, multiples and their mothers had a significantly higher rate of risk factors of child maltreatment.
Agopian, A J; Evans, Jane A; Lupo, Philip J
2018-01-15
It is estimated that 20 to 30% of infants with birth defects have two or more birth defects. Among these infants with multiple congenital anomalies (MCA), co-occurring anomalies may represent either chance (i.e., unrelated etiologies) or pathogenically associated patterns of anomalies. While some MCA patterns have been recognized and described (e.g., known syndromes), others have not been identified or characterized. Elucidating these patterns may result in a better understanding of the etiologies of these MCAs. This article reviews the literature with regard to analytic methods that have been used to evaluate patterns of MCAs, in particular those using birth defect registry data. A popular method for MCA assessment involves a comparison of the observed to expected ratio for a given combination of MCAs, or one of several modified versions of this comparison. Other methods include use of numerical taxonomy or other clustering techniques, multiple regression analysis, and log-linear analysis. Advantages and disadvantages of these approaches, as well as specific applications, were outlined. Despite the availability of multiple analytic approaches, relatively few MCA combinations have been assessed. The availability of large birth defects registries and computing resources that allow for automated, big data strategies for prioritizing MCA patterns may provide for new avenues for better understanding co-occurrence of birth defects. Thus, the selection of an analytic approach may depend on several considerations. Birth Defects Research 110:5-11, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Higher order perturbation theory - An example for discussion
International Nuclear Information System (INIS)
Lewins, J.D.; Parks, G.; Babb, A.L.
1986-01-01
Higher order perturbation theory is developed in the form of a Taylor series expansion to third order to calculate the thermal utilization of a nonuniform cell. The development takes advantage of the self-adjoint property of the diffusion operator to provide a simple development of this illustration of generalized perturbation theory employing scalar perturbation parameters. The results show how a designer might employ a second-order theory to quantify proposed design improvements, together with the limitations of second- and third-order theory. The chosen example has an exact optimization solution and thus provides a clear understanding of the role of perturbation theory at its various orders. Convergence and the computational advantages and disadvantages of the method are discussed
Higher-order force moments of active particles
Nasouri, Babak; Elfring, Gwynn J.
2018-04-01
Active particles moving through fluids generate disturbance flows due to their activity. For simplicity, the induced flow field is often modeled by the leading terms in a far-field approximation of the Stokes equations, whose coefficients are the force, torque, and stresslet (zeroth- and first-order force moments) of the active particle. This level of approximation is quite useful, but may also fail to predict more complex behaviors that are observed experimentally. In this study, to provide a better approximation, we evaluate the contribution of the second-order force moments to the flow field and, by reciprocal theorem, present explicit formulas for the stresslet dipole, rotlet dipole, and potential dipole for an arbitrarily shaped active particle. As examples of this method, we derive modified Faxén laws for active spherical particles and resolve higher-order moments for active rod-like particles.
Higher-order automatic differentiation of mathematical functions
Charpentier, Isabelle; Dal Cappello, Claude
2015-04-01
Functions of mathematical physics such as the Bessel functions, the Chebyshev polynomials, the Gauss hypergeometric function and so forth, have practical applications in many scientific domains. On the one hand, differentiation formulas provided in reference books apply to real or complex variables. These do not account for the chain rule. On the other hand, based on the chain rule, the automatic differentiation has become a natural tool in numerical modeling. Nevertheless automatic differentiation tools do not deal with the numerous mathematical functions. This paper describes formulas and provides codes for the higher-order automatic differentiation of mathematical functions. The first method is based on Faà di Bruno's formula that generalizes the chain rule. The second one makes use of the second order differential equation they satisfy. Both methods are exemplified with the aforementioned functions.
Influence of higher order modes on angled-facet amplifiers
DEFF Research Database (Denmark)
Wang, Z.; Mikkelsen, B.; Stubkjær, Kristian
1991-01-01
The influence of the first-order mode on the residual reflectivity of angled-facet amplifiers is analyzed. For a 7 degrees angled-facet ridge waveguide amplifier with a single-layer antireflective (AR) coating, a gain ripple lower than 1-dB at 25-dB gain can be obtained independent...... of the polarization, even in the presence of a first-order mode with a 15-dB gain. The tolerances for the thickness and refractive index of the AR coating are reduced by a factor of three compared to operation in the fundamental mode only. The influence of the higher order mode can virtually be suppressed...
Higher order branching of periodic orbits from polynomial isochrones
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B. Toni
1999-09-01
Full Text Available We discuss the higher order local bifurcations of limit cycles from polynomial isochrones (linearizable centers when the linearizing transformation is explicitly known and yields a polynomial perturbation one-form. Using a method based on the relative cohomology decomposition of polynomial one-forms complemented with a step reduction process, we give an explicit formula for the overall upper bound of branch points of limit cycles in an arbitrary $n$ degree polynomial perturbation of the linear isochrone, and provide an algorithmic procedure to compute the upper bound at successive orders. We derive a complete analysis of the nonlinear cubic Hamiltonian isochrone and show that at most nine branch points of limit cycles can bifurcate in a cubic polynomial perturbation. Moreover, perturbations with exactly two, three, four, six, and nine local families of limit cycles may be constructed.
Neutron scattering studies on chromatin higher-order structure
Energy Technology Data Exchange (ETDEWEB)
Graziano, V.; Gerchman, S.E.; Schneider, D.K.; Ramakrishnan, V. [Brookhaven National Laboratory, Upton, NY (United States)
1994-12-31
We have been engaged in studies of the structure and condensation of chromatin into the 30nm filament using small-angle neutron scattering. We have also used deuterated histone H1 to determine its location in the chromatin 30nm filament. Our studies indicate that chromatin condenses with increasing ionic strength to a limiting structure that has a mass per unit length of 6-7 nucleosomes/11 nm. They also show that the linker histone H1/H5 is located in the interior of the chromatin filament, in a position compatible with its binding to the inner face of the nucleosome. Analysis of the mass per unit length as a function of H5 stoichiometry suggests that 5-7 contiguous nucleosomes need to have H5 bound before a stable higher order structure can exist.
Minimization of heat slab nodes with higher order boundary conditions
International Nuclear Information System (INIS)
Solbrig, C.W.
1992-01-01
The accuracy of a numerical solution can be limited by the numerical approximation to the boundary conditions rather than the accuracy of the equations which describe the interior. The study presented in this paper compares the results from two different numerical formulations of the convective boundary condition on the face of a heat transfer slab. The standard representation of the boundary condition in a test problem yielded an unacceptable error even when the heat transfer slab was partitioned into over 300 nodes. A higher order boundary condition representation was obtained by using a second order approximation for the first derivative at the boundary and combining it with the general equation used for inner nodes. This latter formulation produced reasonable results when as few as ten nodes were used
Mixed Higher Order Variational Model for Image Recovery
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Pengfei Liu
2014-01-01
Full Text Available A novel mixed higher order regularizer involving the first and second degree image derivatives is proposed in this paper. Using spectral decomposition, we reformulate the new regularizer as a weighted L1-L2 mixed norm of image derivatives. Due to the equivalent formulation of the proposed regularizer, an efficient fast projected gradient algorithm combined with monotone fast iterative shrinkage thresholding, called, FPG-MFISTA, is designed to solve the resulting variational image recovery problems under majorization-minimization framework. Finally, we demonstrate the effectiveness of the proposed regularization scheme by the experimental comparisons with total variation (TV scheme, nonlocal TV scheme, and current second degree methods. Specifically, the proposed approach achieves better results than related state-of-the-art methods in terms of peak signal to ratio (PSNR and restoration quality.
MHD stability analysis using higher order spline functions
Energy Technology Data Exchange (ETDEWEB)
Ida, Akihiro [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Nagoya, Aichi (Japan); Todoroki, Jiro; Sanuki, Heiji
1999-04-01
The eigenvalue problem of the linearized magnetohydrodynamic (MHD) equation is formulated by using higher order spline functions as the base functions of Ritz-Galerkin approximation. When the displacement vector normal to the magnetic surface (in the magnetic surface) is interpolated by B-spline functions of degree p{sub 1} (degree p{sub 2}), which is continuously c{sub 1}-th (c{sub 2}-th) differentiable on neighboring finite elements, the sufficient conditions for the good approximation is given by p{sub 1}{>=}p{sub 2}+1, c{sub 1}{<=}c{sub 2}+1, (c{sub 1}{>=}1, p{sub 2}{>=}c{sub 2}{>=}0). The influence of the numerical integration upon the convergence of calculated eigenvalues is discussed. (author)
Higher-order momentum distributions and locally affine LDDMM registration
DEFF Research Database (Denmark)
Sommer, Stefan Horst; Nielsen, Mads; Darkner, Sune
2013-01-01
description of affine transformations and subsequent compact description of non-translational movement in a globally nonrigid deformation. The resulting representation contains directly interpretable information from both mathematical and modeling perspectives. We develop the mathematical construction......To achieve sparse parametrizations that allow intuitive analysis, we aim to represent deformation with a basis containing interpretable elements, and we wish to use elements that have the description capacity to represent the deformation compactly. To accomplish this, we introduce in this paper...... higher-order momentum distributions in the large deformation diffeomorphic metric mapping (LDDMM) registration framework. While the zeroth-order moments previously used in LDDMM only describe local displacement, the first-order momenta that are proposed here represent a basis that allows local...
Higher-order structure of Saccharomyces cerevisiae chromatin
International Nuclear Information System (INIS)
Lowary, P.T.; Widom, J.
1989-01-01
We have developed a method for partially purifying chromatin from Saccharomyces cerevisiae (baker's yeast) to a level suitable for studies of its higher-order folding. This has required the use of yeast strains that are free of the ubiquitous yeast killer virus. Results from dynamic light scattering, electron microscopy, and x-ray diffraction show that the yeast chromatin undergoes a cation-dependent folding into 30-nm filaments that resemble those characteristic of higher-cell chromatin; moreover, the packing of nucleosomes within the yeast 30-nm filaments is similar to that of higher cells. These results imply that yeast has a protein or protein domain that serves the role of the histone H 1 found in higher cells; physical and genetic studies of the yeast activity could help elucidate the structure and function of H 1. Images of the yeast 30-nm filaments can be used to test crossed-linker models for 30-nm filament structure
Higher order corrections to asymptotic-de Sitter inflation
Mohsenzadeh, M.; Yusofi, E.
2017-08-01
Since trans-Planckian considerations can be associated with the re-definition of the initial vacuum, we investigate further the influence of trans-Planckian physics on the spectra produced by the initial quasi-de Sitter (dS) state during inflation. We use the asymptotic-dS mode to study the trans-Planckian correction of the power spectrum to the quasi-dS inflation. The obtained spectra consist of higher order corrections associated with the type of geometry and harmonic terms sensitive to the fluctuations of space-time (or gravitational waves) during inflation. As an important result, the amplitude of the power spectrum is dependent on the choice of c, i.e. the type of space-time in the period of inflation. Also, the results are always valid for any asymptotic dS space-time and particularly coincide with the conventional results for dS and flat space-time.
Higher-order techniques for some problems of nonlinear control
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Sarychev Andrey V.
2002-01-01
Full Text Available A natural first step when dealing with a nonlinear problem is an application of some version of linearization principle. This includes the well known linearization principles for controllability, observability and stability and also first-order optimality conditions such as Lagrange multipliers rule or Pontryagin's maximum principle. In many interesting and important problems of nonlinear control the linearization principle fails to provide a solution. In the present paper we provide some examples of how higher-order methods of differential geometric control theory can be used for the study nonlinear control systems in such cases. The presentation includes: nonlinear systems with impulsive and distribution-like inputs; second-order optimality conditions for bang–bang extremals of optimal control problems; methods of high-order averaging for studying stability and stabilization of time-variant control systems.
Neutron scattering studies on chromatin higher-order structure
International Nuclear Information System (INIS)
Graziano, V.; Gerchman, S.E.; Schneider, D.K.; Ramakrishnan, V.
1994-01-01
We have been engaged in studies of the structure and condensation of chromatin into the 30nm filament using small-angle neutron scattering. We have also used deuterated histone H1 to determine its location in the chromatin 30nm filament. Our studies indicate that chromatin condenses with increasing ionic strength to a limiting structure that has a mass per unit length of 6-7 nucleosomes/11 nm. They also show that the linker histone H1/H5 is located in the interior of the chromatin filament, in a position compatible with its binding to the inner face of the nucleosome. Analysis of the mass per unit length as a function of H5 stoichiometry suggests that 5-7 contiguous nucleosomes need to have H5 bound before a stable higher order structure can exist
Higher order statistical moment application for solar PV potential analysis
Basri, Mohd Juhari Mat; Abdullah, Samizee; Azrulhisham, Engku Ahmad; Harun, Khairulezuan
2016-10-01
Solar photovoltaic energy could be as alternative energy to fossil fuel, which is depleting and posing a global warming problem. However, this renewable energy is so variable and intermittent to be relied on. Therefore the knowledge of energy potential is very important for any site to build this solar photovoltaic power generation system. Here, the application of higher order statistical moment model is being analyzed using data collected from 5MW grid-connected photovoltaic system. Due to the dynamic changes of skewness and kurtosis of AC power and solar irradiance distributions of the solar farm, Pearson system where the probability distribution is calculated by matching their theoretical moments with that of the empirical moments of a distribution could be suitable for this purpose. On the advantage of the Pearson system in MATLAB, a software programming has been developed to help in data processing for distribution fitting and potential analysis for future projection of amount of AC power and solar irradiance availability.
Recognition of higher order patterns in proteins: immunologic kernels.
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Robert D Bremel
Full Text Available By applying analysis of the principal components of amino acid physical properties we predicted cathepsin cleavage sites, MHC binding affinity, and probability of B-cell epitope binding of peptides in tetanus toxin and in ten diverse additional proteins. Cross-correlation of these metrics, for peptides of all possible amino acid index positions, each evaluated in the context of a ±25 amino acid flanking region, indicated that there is a strongly repetitive pattern of short peptides of approximately thirty amino acids each bounded by cathepsin cleavage sites and each comprising B-cell linear epitopes, MHC-I and MHC-II binding peptides. Such "immunologic kernel" peptides comprise all signals necessary for adaptive immunologic cognition, response and recall. The patterns described indicate a higher order spatial integration that forms a symbolic logic coordinating the adaptive immune system.
Higher-order phase transitions on financial markets
Kasprzak, A.; Kutner, R.; Perelló, J.; Masoliver, J.
2010-08-01
Statistical and thermodynamic properties of the anomalous multifractal structure of random interevent (or intertransaction) times were thoroughly studied by using the extended continuous-time random walk (CTRW) formalism of Montroll, Weiss, Scher, and Lax. Although this formalism is quite general (and can be applied to any interhuman communication with nontrivial priority), we consider it in the context of a financial market where heterogeneous agent activities can occur within a wide spectrum of time scales. As the main general consequence, we found (by additionally using the Saddle-Point Approximation) the scaling or power-dependent form of the partition function, Z(q'). It diverges for any negative scaling powers q' (which justifies the name anomalous) while for positive ones it shows the scaling with the general exponent τ(q'). This exponent is the nonanalytic (singular) or noninteger power of q', which is one of the pilar of higher-order phase transitions. In definition of the partition function we used the pausing-time distribution (PTD) as the central one, which takes the form of convolution (or superstatistics used, e.g. for describing turbulence as well as the financial market). Its integral kernel is given by the stretched exponential distribution (often used in disordered systems). This kernel extends both the exponential distribution assumed in the original version of the CTRW formalism (for description of the transient photocurrent measured in amorphous glassy material) as well as the Gaussian one sometimes used in this context (e.g. for diffusion of hydrogen in amorphous metals or for aging effects in glasses). Our most important finding is the third- and higher-order phase transitions, which can be roughly interpreted as transitions between the phase where high frequency trading is most visible and the phase defined by low frequency trading. The specific order of the phase transition directly depends upon the shape exponent α defining the stretched
Higher-order conditioning is impaired by hippocampal lesions.
Gilboa, Asaf; Sekeres, Melanie; Moscovitch, Morris; Winocur, Gordon
2014-09-22
Behavior in the real world is rarely motivated by primary conditioned stimuli that have been directly associated with potent unconditioned reinforcers. Instead, motivation and choice behavior are driven by complex chains of higher-order associations that are only indirectly linked to intrinsic reward and often exert their influence outside awareness. Second-order conditioning (SOC) [1] is a basic associative-learning mechanism whereby stimuli acquire motivational salience by proxy, in the absence of primary incentives [2, 3]. Memory-systems theories consider first-order conditioning (FOC) and SOC to be prime examples of hippocampal-independent nondeclarative memory [4, 5]. Accordingly, neurobiological models of SOC focus almost exclusively on nondeclarative neural systems that support motivational salience and reward value. Transfer of value from a conditioned stimulus to a neutral stimulus is thought to require the basolateral amygdala [6, 7] and the ventral striatum [2, 3], but not the hippocampus. We developed a new paradigm to measure appetitive SOC of tones in rats. Hippocampal lesions severely impaired both acquisition and expression of SOC despite normal FOC. Unlike controls, rats with hippocampal lesions could not discriminate between positive and negative secondary conditioned tones, although they exhibited general familiarity with previously presented tones compared with new tones. Importantly, normal rats' behavior, in contrast to that of hippocampal groups, also revealed different confidence levels as indexed by effort, a central characteristic of hippocampal relational memory. The results indicate, contrary to current systems models, that representations of intrinsic relationships between reward value, stimulus identity, and motivation require hippocampal mediation when these relationships are of a higher order. Copyright © 2014 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Scheepers Hubertina CJ
2007-06-01
Full Text Available Abstract Background 15% of multiple pregnancies ends in a preterm delivery, which can lead to mortality and severe long term neonatal morbidity. At present, no generally accepted strategy for the prevention of preterm birth in multiple pregnancies exists. Prophylactic administration of 17-alpha hydroxyprogesterone caproate (17OHPC has proven to be effective in the prevention of preterm birth in women with singleton pregnancies with a previous preterm delivery. At present, there are no data on the effectiveness of progesterone in the prevention of preterm birth in multiple pregnancies. Methods/Design We aim to investigate the hypothesis that 17OHPC will reduce the incidence of the composite neonatal morbidity of neonates by reducing the early preterm birth rate in multiple pregnancies. Women with a multiple pregnancy at a gestational age between 15 and 20 weeks of gestation will be entered in a placebo-controlled, double blinded randomised study comparing weekly 250 mg 17OHPC intramuscular injections from 16–20 weeks up to 36 weeks of gestation versus placebo. At study entry, cervical length will be measured. The primary outcome is composite bad neonatal condition (perinatal death or severe morbidity. Secondary outcome measures are time to delivery, preterm birth rate before 32 and 37 weeks, days of admission in neonatal intensive care unit, maternal morbidity, maternal admission days for preterm labour and costs. We need to include 660 women to indicate a reduction in bad neonatal outcome from 15% to 8%. Analysis will be by intention to treat. We will also analyse whether the treatment effect is dependent on cervical length. Discussion This trial will provide evidence as to whether or not 17OHPC-treatment is an effective means of preventing bad neonatal outcome due to preterm birth in multiple pregnancies. Trial registration Current Controlled Trials ISRCTN40512715
Factors associated with low birth weight in Nepal using multiple imputation
Directory of Open Access Journals (Sweden)
Usha Singh
2017-02-01
Full Text Available Abstract Background Survey data from low income countries on birth weight usually pose a persistent problem. The studies conducted on birth weight have acknowledged missing data on birth weight, but they are not included in the analysis. Furthermore, other missing data presented on determinants of birth weight are not addressed. Thus, this study tries to identify determinants that are associated with low birth weight (LBW using multiple imputation to handle missing data on birth weight and its determinants. Methods The child dataset from Nepal Demographic and Health Survey (NDHS, 2011 was utilized in this study. A total of 5,240 children were born between 2006 and 2011, out of which 87% had at least one measured variable missing and 21% had no recorded birth weight. All the analyses were carried out in R version 3.1.3. Transform-then impute method was applied to check for interaction between explanatory variables and imputed missing data. Survey package was applied to each imputed dataset to account for survey design and sampling method. Survey logistic regression was applied to identify the determinants associated with LBW. Results The prevalence of LBW was 15.4% after imputation. Women with the highest autonomy on their own health compared to those with health decisions involving husband or others (adjusted odds ratio (OR 1.87, 95% confidence interval (95% CI = 1.31, 2.67, and husband and women together (adjusted OR 1.57, 95% CI = 1.05, 2.35 were less likely to give birth to LBW infants. Mothers using highly polluting cooking fuels (adjusted OR 1.49, 95% CI = 1.03, 2.22 were more likely to give birth to LBW infants than mothers using non-polluting cooking fuels. Conclusion The findings of this study suggested that obtaining the prevalence of LBW from only the sample of measured birth weight and ignoring missing data results in underestimation.
Higher order effects in electroweak theory 1981-12 (KEK)
International Nuclear Information System (INIS)
Aoki, Ken-ichi
1982-01-01
This is a brief report on the higher order or loop effects in electroweak theory. The discussion is based on the Weinberg Salam model and QCD. The loop correction to weak interaction is described. The renormalization conditions were applied to physical parameters, α(QED), M(W) and M(Z). It is expected to obtain experimentally the values of M(W) and M(Z) with the accuracy of 0.1 percent. In this scheme, the parameters were fixed loop by loop. The correction was evaluated along the present on-shell scheme. The general estimation of the order of correction was performed. The evaluation of the size of terms in one-loop correction was made. The examples of one loop analysis are presented. The leading logarithmic correction such as α ln(m 2 q 2 /M 2 ) is discussed. The system was described by H(eff) with the local operator O(i), in which the propagator of heavy particles was contracted. The effective interaction was obtained as C(i) (q 2 ) O(i), where C(i)(q 2 ) satisfies a proper equation of a renormalization group. As the practical examples, μ-decay, charged current and neutral current were studied. The correction to electron neutral current and the shift of M(W) and M(Z) were numerically obtained. Comments on quark mass and the uncertainty of sin 2 (theta) from the νN reaction are presented. (Kato, T.)
Higher-order scalar interactions and SM vacuum stability
Energy Technology Data Exchange (ETDEWEB)
Lalak, Zygmunt; Lewicki, Marek; Olszewski, Paweł [Institute of Theoretical Physics, Faculty of Physics, University of Warsawul. Hoża 69, Warsaw (Poland)
2014-05-26
Investigation of the structure of the Standard Model effective potential at very large field strengths opens a window towards new phenomena and can reveal properties of the UV completion of the SM. The map of the lifetimes of the vacua of the SM enhanced by nonrenormalizable scalar couplings has been compiled to show how new interactions modify stability of the electroweak vacuum. Whereas it is possible to stabilize the SM by adding Planck scale suppressed interactions and taking into account running of the new couplings, the generic effect is shortening the lifetime and hence further destabilisation of the SM electroweak vacuum. These findings have been illustrated with phase diagrams of modified SM-like models. It has been demonstrated that stabilisation can be achieved by lowering the suppression scale of higher order operators while picking up such combinations of new couplings, which do not deepen the new minima of the potential. Our results show the dependence of the lifetime of the electroweak minimum on the magnitude of the new couplings, including cases with very small couplings (which means very large effective suppression scale) and couplings vastly different in magnitude (which corresponds to two different suppression scales)
General relativity and gauge gravity theories of higher order
International Nuclear Information System (INIS)
Konopleva, N.P.
1998-01-01
It is a short review of today's gauge gravity theories and their relations with Einstein General Relativity. The conceptions of construction of the gauge gravity theories with higher derivatives are analyzed. GR is regarded as the gauge gravity theory corresponding to the choice of G ∞4 as the local gauge symmetry group and the symmetrical tensor of rank two g μν as the field variable. Using the mathematical technique, single for all fundamental interactions (namely variational formalism for infinite Lie groups), we can obtain Einstein's theory as the gauge theory without any changes. All other gauge approaches lead to non-Einstein theories of gravity. But above-mentioned mathematical technique permits us to construct the gauge gravity theory of higher order (for instance SO (3,1)-gravity) so that all vacuum solutions of Einstein equations are the solutions of the SO (3,1)-gravity theory. The structure of equations of SO(3,1)-gravity becomes analogous to Weeler-Misner geometrodynamics one
Predicting perceptual learning from higher-order cortical processing.
Wang, Fang; Huang, Jing; Lv, Yaping; Ma, Xiaoli; Yang, Bin; Wang, Encong; Du, Boqi; Li, Wu; Song, Yan
2016-01-01
Visual perceptual learning has been shown to be highly specific to the retinotopic location and attributes of the trained stimulus. Recent psychophysical studies suggest that these specificities, which have been associated with early retinotopic visual cortex, may in fact not be inherent in perceptual learning and could be related to higher-order brain functions. Here we provide direct electrophysiological evidence in support of this proposition. In a series of event-related potential (ERP) experiments, we recorded high-density electroencephalography (EEG) from human adults over the course of learning in a texture discrimination task (TDT). The results consistently showed that the earliest C1 component (68-84ms), known to reflect V1 activity driven by feedforward inputs, was not modulated by learning regardless of whether the behavioral improvement is location specific or not. In contrast, two later posterior ERP components (posterior P1 and P160-350) over the occipital cortex and one anterior ERP component (anterior P160-350) over the prefrontal cortex were progressively modified day by day. Moreover, the change of the anterior component was closely correlated with improved behavioral performance on a daily basis. Consistent with recent psychophysical and imaging observations, our results indicate that perceptual learning can mainly involve changes in higher-level visual cortex as well as in the neural networks responsible for cognitive functions such as attention and decision making. Copyright © 2015 Elsevier Inc. All rights reserved.
Estimation of uncertainties from missing higher orders in perturbative calculations
International Nuclear Information System (INIS)
Bagnaschi, E.
2015-05-01
In this proceeding we present the results of our recent study (hep-ph/1409.5036) of the statistical performances of two different approaches, Scale Variation (SV) and the Bayesian model of Cacciari and Houdeau (CH)(hep-ph/1105.5152) (which we also extend to observables with initial state hadrons), to the estimation of Missing Higher-Order Uncertainties (MHOUs)(hep-ph/1307.1843) in perturbation theory. The behavior of the models is determined by analyzing, on a wide set of observables, how the MHOU intervals they produce are successful in predicting the next orders. We observe that the Bayesian model behaves consistently, producing intervals at 68% Degree of Belief (DoB) comparable with the scale variation intervals with a rescaling factor r larger than 2 and closer to 4. Concerning SV, our analysis allows the derivation of a heuristic Confidence Level (CL) for the intervals. We find that assigning a CL of 68% to the intervals obtained with the conventional choice of varying the scales within a factor of two with respect to the central scale could potentially lead to an underestimation of the uncertainties in the case of observables with initial state hadrons.
Higher-Order Synaptic Interactions Coordinate Dynamics in Recurrent Networks.
Directory of Open Access Journals (Sweden)
Brendan Chambers
2016-08-01
Full Text Available Linking synaptic connectivity to dynamics is key to understanding information processing in neocortex. Circuit dynamics emerge from complex interactions of interconnected neurons, necessitating that links between connectivity and dynamics be evaluated at the network level. Here we map propagating activity in large neuronal ensembles from mouse neocortex and compare it to a recurrent network model, where connectivity can be precisely measured and manipulated. We find that a dynamical feature dominates statistical descriptions of propagating activity for both neocortex and the model: convergent clusters comprised of fan-in triangle motifs, where two input neurons are themselves connected. Fan-in triangles coordinate the timing of presynaptic inputs during ongoing activity to effectively generate postsynaptic spiking. As a result, paradoxically, fan-in triangles dominate the statistics of spike propagation even in randomly connected recurrent networks. Interplay between higher-order synaptic connectivity and the integrative properties of neurons constrains the structure of network dynamics and shapes the routing of information in neocortex.
Effective description of higher-order scalar-tensor theories
Energy Technology Data Exchange (ETDEWEB)
Langlois, David [APC—Astroparticule et Cosmologie, Université Paris Diderot Paris 7, 75013 Paris (France); Mancarella, Michele; Vernizzi, Filippo [Institut de physique théorique, Université Paris Saclay, CEA, CNRS, 91191 Gif-sur-Yvette (France); Noui, Karim, E-mail: langlois@apc.univ-paris7.fr, E-mail: michele.mancarella@cea.fr, E-mail: karim.noui@lmpt.univ-tours.fr, E-mail: filippo.vernizzi@cea.fr [Laboratoire de Mathématiques et Physique Théorique, Université François Rabelais, Parc de Grandmont, 37200 Tours (France)
2017-05-01
Most existing theories of dark energy and/or modified gravity, involving a scalar degree of freedom, can be conveniently described within the framework of the Effective Theory of Dark Energy, based on the unitary gauge where the scalar field is uniform. We extend this effective approach by allowing the Lagrangian in unitary gauge to depend on the time derivative of the lapse function. Although this dependence generically signals the presence of an extra scalar degree of freedom, theories that contain only one propagating scalar degree of freedom, in addition to the usual tensor modes, can be constructed by requiring the initial Lagrangian to be degenerate. Starting from a general quadratic action, we derive the dispersion relations for the linear perturbations around Minkowski and a cosmological background. Our analysis directly applies to the recently introduced Degenerate Higher-Order Scalar-Tensor (DHOST) theories. For these theories, we find that one cannot recover a Poisson-like equation in the static linear regime except for the subclass that includes the Horndeski and so-called 'beyond Horndeski' theories. We also discuss Lorentz-breaking models inspired by Horava gravity.
Higher order mode analysis of the SNS superconducting linac
Sang Ho Kim; Dong Jeon; Sundelin, R
2001-01-01
Higher order modes (HOM's) of monopoles, dipoles, quadrupoles and sextupoles in beta =0.61 and beta =0.81 6-cell superconducting (SC) cavities for the Spallation Neutron Source (SNS) project, have been found up to about 3 GHz and their properties such as R/Q, trapping possibility, etc have been figured out concerning manufacturing imperfection. The main issues of HOM's are beam instabilities (published separately) and HOM induced power especially from TM monopoles. The time structure of SNS beam has three different time scales of pulses, which are micro-pulse, midi-pulse and macropulse. Each time structure will generate resonances. When a mode is near these resonance frequencies, the induced voltage could be large and accordingly the resulting HOM power. In order to understand the effects from such a complex beam time structure on the mode excitation and resulting HOM power, analytic expressions are developed. With these analytic expressions, the induced HOM voltage and HOM power were calculated by assuming e...
Scalar brane backgrounds in higher order curvature gravity
International Nuclear Information System (INIS)
Charmousis, Christos; Davis, Stephen C.; Dufaux, Jean-Francois
2003-01-01
We investigate maximally symmetric brane world solutions with a scalar field. Five-dimensional bulk gravity is described by a general lagrangian which yields field equations containing no higher than second order derivatives. This includes the Gauss-Bonnet combination for the graviton. Stability and gravitational properties of such solutions are considered, and we particularly emphasise the modifications induced by the higher order terms. In particular it is shown that higher curvature corrections to Einstein theory can give rise to instabilities in brane world solutions. A method for analytically obtaining the general solution for such actions is outlined. Generically, the requirement of a finite volume element together with the absence of a naked singularity in the bulk imposes fine-tuning of the brane tension. A model with a moduli scalar field is analysed in detail and we address questions of instability and non-singular self-tuning solutions. In particular, we discuss a case with a normalisable zero mode but infinite volume element. (author)
Analysis of higher order harmonics with holographic reflection gratings
Mas-Abellan, P.; Madrigal, R.; Fimia, A.
2017-05-01
Silver halide emulsions have been considered one of the most energetic sensitive materials for holographic applications. Nonlinear recording effects on holographic reflection gratings recorded on silver halide emulsions have been studied by different authors obtaining excellent experimental results. In this communication specifically we focused our investigation on the effects of refractive index modulation, trying to get high levels of overmodulation that will produce high order harmonics. We studied the influence of the overmodulation and its effects on the transmission spectra for a wide exposure range by use of 9 μm thickness films of ultrafine grain emulsion BB640, exposed to single collimated beams using a red He-Ne laser (wavelength 632.8 nm) with Denisyuk configuration obtaining a spatial frequency of 4990 l/mm recorded on the emulsion. The experimental results show that high overmodulation levels of refractive index produce second order harmonics with high diffraction efficiency (higher than 75%) and a narrow grating bandwidth (12.5 nm). Results also show that overmodulation produce diffraction spectra deformation of the second order harmonic, transforming the spectrum from sinusoidal to approximation of square shape due to very high overmodulation. Increasing the levels of overmodulation of refractive index, we have obtained higher order harmonics, obtaining third order harmonic with diffraction efficiency (up to 23%) and narrowing grating bandwidth (5 nm). This study is the first step to develop a new easy technique to obtain narrow spectral filters based on the use of high index modulation reflection gratings.
Correlated stopping, proton clusters and higher order proton cumulants
Energy Technology Data Exchange (ETDEWEB)
Bzdak, Adam [AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow (Poland); Koch, Volker [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Skokov, Vladimir [RIKEN/BNL, Brookhaven National Laboratory, Upton, NY (United States)
2017-05-15
We investigate possible effects of correlations between stopped nucleons on higher order proton cumulants at low energy heavy-ion collisions. We find that fluctuations of the number of wounded nucleons N{sub part} lead to rather nontrivial dependence of the correlations on the centrality; however, this effect is too small to explain the large and positive four-proton correlations found in the preliminary data collected by the STAR collaboration at √(s) = 7.7 GeV. We further demonstrate that, by taking into account additional proton clustering, we are able to qualitatively reproduce the preliminary experimental data. We speculate that this clustering may originate either from collective/multi-collision stopping which is expected to be effective at lower energies or from a possible first-order phase transition, or from (attractive) final state interactions. To test these ideas we propose to measure a mixed multi-particle correlation between stopped protons and a produced particle (e.g. pion, antiproton). (orig.)
Near integrability of kink lattice with higher order interactions
Jiang, Yun-Guo; Liu, Jia-Zhen; He, Song
2017-11-01
We make use of Manton’s analytical method to investigate the force between kinks and anti-kinks at large distances in 1+1 dimensional field theory. The related potential has infinite order corrections of exponential pattern, and the coefficients for each order are determined. These coefficients can also be obtained by solving the equation of the fluctuations around the vacuum. At the lowest order, the kink lattice represents the Toda lattice. With higher order correction terms, the kink lattice can represent one kind of generic Toda lattice. With only two sites, the kink lattice is classically integrable. If the number of sites of the lattice is larger than two, the kink lattice is not integrable but is a near integrable system. We make use of Flaschka’s variables to study the Lax pair of the kink lattice. These Flaschka’s variables have interesting algebraic relations and non-integrability can be manifested. We also discuss the higher Hamiltonians for the deformed open Toda lattice, which has a similar result to the ordinary deformed Toda. Supported by Shandong Provincial Natural Science Foundation (ZR2014AQ007), National Natural Science Foundation of China (11403015, U1531105), S. He is supported by Max-Planck fellowship in Germany and National Natural Science Foundation of China (11305235)
Higher order corrections to energy levels of muonic atoms
International Nuclear Information System (INIS)
Rinker, G.A. Jr.; Steffen, R.M.
1975-08-01
In order to facilitate the analysis of muonic x-ray spectra, the results of numerical computations of all higher order quantum electrodynamical corrections to the energy levels of muonic atoms are presented in tabular and graphical form. These corrections include the vacuum polarization corrections caused by emission and reabsorption of virtual electron pairs to all orders, including ''double-bubble'' and ''cracked-egg'' diagrams. An estimate of the Delbruecke scattering-type correction is presented. The Lamb-shift (second- and fourth-order vertex) corrections have been calculated including the correction for the anomalous magnetic moment of the muon. The relativistic nuclear motion (or recoil) correction as well as the correction caused by the screening of the atomic electrons is presented in graphs. For the sake of completeness a graph of the nuclear polarization as computed on the basis of Chen's approach has been included. All calculations were made with a two-parameter Fermi distribution of the nuclear charge density. 7 figures, 23 references
Higher-order relativistic periastron advances and binary pulsars
International Nuclear Information System (INIS)
Damour, T.; Schafer, G.
1988-01-01
The contributions to the periastron advance of a system of two condensed bodies coming from relativistic dynamical effects of order higher than the usual first post-Newtonian (1PN) equations of motion are investigated. The structure of the solution of the orbital second post-Newtonian (2PN) equations of motion is given in a simple parametrized form. The contributions to the secular pariastron advance, and the period, of orbital 2PN effects are then explicitly worked out by using the Hamilton-Jacobi method. The spin-orbit contribution to the secular precession of the orbit in space is rederived in a streamlined way by making full use of Hamiltonian methods. These results are then applied to the theoretical interpretation of the observational data of pulsars in close eccentric binary systems. It is shown that the higher-order relativistic contributions are already of theoretical and astophysical significance for interpreting the high-precision measurement of the secular periastron advance of PSR 1913+16 achived by Taylor and coworkers. The case of extremely fast spinning (millisecond) binary pulsars is also discussed, and shown to offer an easier ground for getting new tests of general relativity, and/or, a direct measurement of the moment of inertia of a neutron star
Higher Order Modes Excitation of Micro Cantilever Beams
Jaber, Nizar
2014-05-01
In this study, we present analytical and experimental investigation of electrically actuated micro cantilever based resonators. These devices are fabricated using polyimide and coated with chrome and gold layers from both sides. The cantilevers are highly curled up due to stress gradient, which is a common imperfection in surface micro machining. Using a laser Doppler vibrometer, we applied a noise signal to experimentally find the first four resonance frequencies. Then, using a data acquisition card, we swept the excitation frequency around the first four natural modes of vibrations. Theoretically, we derived a reduced order model using the Galerkin method to simulate the dynamics of the system. Extensive numerical analysis and computations were performed. The numerical analysis was able to provide good matching with experimental values of the resonance frequencies. Also, we proved the ability to excite higher order modes using partial electrodes with shapes that resemble the shape of the mode of interest. Such micro-resonators are shown to be promising for applications in mass and gas sensing.
Holographic conductivity of holographic superconductors with higher-order corrections
Energy Technology Data Exchange (ETDEWEB)
Sheykhi, Ahmad [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Ghazanfari, Afsoon; Dehyadegari, Amin [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of)
2018-02-15
We analytically and numerically disclose the effects of the higher-order correction terms in the gravity and in the gauge field on the properties of s-wave holographic superconductors. On the gravity side, we consider the higher curvature Gauss-Bonnet corrections and on the gauge field side, we add a quadratic correction term to the Maxwell Lagrangian. We show that, for this system, one can still obtain an analytical relation between the critical temperature and the charge density. We also calculate the critical exponent and the condensation value both analytically and numerically. We use a variational method, based on the Sturm-Liouville eigenvalue problem for our analytical study, as well as a numerical shooting method in order to compare with our analytical results. For a fixed value of the Gauss-Bonnet parameter, we observe that the critical temperature decreases with increasing the nonlinearity of the gauge field. This implies that the nonlinear correction term to the Maxwell electrodynamics makes the condensation harder. We also study the holographic conductivity of the system and disclose the effects of the Gauss-Bonnet and nonlinear parameters α and b on the superconducting gap. We observe that, for various values of α and b, the real part of the conductivity is proportional to the frequency per temperature, ω/T, as the frequency is large enough. Besides, the conductivity has a minimum in the imaginary part which is shifted toward greater frequency with decreasing temperature. (orig.)
Higher-order scene statistics of breast images
Abbey, Craig K.; Sohl-Dickstein, Jascha N.; Olshausen, Bruno A.; Eckstein, Miguel P.; Boone, John M.
2009-02-01
Researchers studying human and computer vision have found description and construction of these systems greatly aided by analysis of the statistical properties of naturally occurring scenes. More specifically, it has been found that receptive fields with directional selectivity and bandwidth properties similar to mammalian visual systems are more closely matched to the statistics of natural scenes. It is argued that this allows for sparse representation of the independent components of natural images [Olshausen and Field, Nature, 1996]. These theories have important implications for medical image perception. For example, will a system that is designed to represent the independent components of natural scenes, where objects occlude one another and illumination is typically reflected, be appropriate for X-ray imaging, where features superimpose on one another and illumination is transmissive? In this research we begin to examine these issues by evaluating higher-order statistical properties of breast images from X-ray projection mammography (PM) and dedicated breast computed tomography (bCT). We evaluate kurtosis in responses of octave bandwidth Gabor filters applied to PM and to coronal slices of bCT scans. We find that kurtosis in PM rises and quickly saturates for filter center frequencies with an average value above 0.95. By contrast, kurtosis in bCT peaks near 0.20 cyc/mm with kurtosis of approximately 2. Our findings suggest that the human visual system may be tuned to represent breast tissue more effectively in bCT over a specific range of spatial frequencies.
Higher-order Skyrme hair of black holes
Gudnason, Sven Bjarke; Nitta, Muneto
2018-05-01
Higher-order derivative terms are considered as replacement for the Skyrme term in an Einstein-Skyrme-like model in order to pinpoint which properties are necessary for a black hole to possess stable static scalar hair. We find two new models able to support stable black hole hair in the limit of the Skyrme term being turned off. They contain 8 and 12 derivatives, respectively, and are roughly the Skyrme-term squared and the so-called BPS-Skyrme-term squared. In the twelfth-order model we find that the lower branches, which are normally unstable, become stable in the limit where the Skyrme term is turned off. We check this claim with a linear stability analysis. Finally, we find for a certain range of the gravitational coupling and horizon radius, that the twelfth-order model contains 4 solutions as opposed to 2. More surprisingly, the lowest part of the would-be unstable branch turns out to be the stable one of the 4 solutions.
Higher order total variation regularization for EIT reconstruction.
Gong, Bo; Schullcke, Benjamin; Krueger-Ziolek, Sabine; Zhang, Fan; Mueller-Lisse, Ullrich; Moeller, Knut
2018-01-08
Electrical impedance tomography (EIT) attempts to reveal the conductivity distribution of a domain based on the electrical boundary condition. This is an ill-posed inverse problem; its solution is very unstable. Total variation (TV) regularization is one of the techniques commonly employed to stabilize reconstructions. However, it is well known that TV regularization induces staircase effects, which are not realistic in clinical applications. To reduce such artifacts, modified TV regularization terms considering a higher order differential operator were developed in several previous studies. One of them is called total generalized variation (TGV) regularization. TGV regularization has been successively applied in image processing in a regular grid context. In this study, we adapted TGV regularization to the finite element model (FEM) framework for EIT reconstruction. Reconstructions using simulation and clinical data were performed. First results indicate that, in comparison to TV regularization, TGV regularization promotes more realistic images. Graphical abstract Reconstructed conductivity changes located on selected vertical lines. For each of the reconstructed images as well as the ground truth image, conductivity changes located along the selected left and right vertical lines are plotted. In these plots, the notation GT in the legend stands for ground truth, TV stands for total variation method, and TGV stands for total generalized variation method. Reconstructed conductivity distributions from the GREIT algorithm are also demonstrated.
Higher-order gravity and the classical equivalence principle
Accioly, Antonio; Herdy, Wallace
2017-11-01
As is well known, the deflection of any particle by a gravitational field within the context of Einstein’s general relativity — which is a geometrical theory — is, of course, nondispersive. Nevertheless, as we shall show in this paper, the mentioned result will change totally if the bending is analyzed — at the tree level — in the framework of higher-order gravity. Indeed, to first order, the deflection angle corresponding to the scattering of different quantum particles by the gravitational field mentioned above is not only spin dependent, it is also dispersive (energy-dependent). Consequently, it violates the classical equivalence principle (universality of free fall, or equality of inertial and gravitational masses) which is a nonlocal principle. However, contrary to popular belief, it is in agreement with the weak equivalence principle which is nothing but a statement about purely local effects. It is worthy of note that the weak equivalence principle encompasses the classical equivalence principle locally. We also show that the claim that there exists an incompatibility between quantum mechanics and the weak equivalence principle, is incorrect.
On the formulations of higher-order strain gradient crystal plasticity models
DEFF Research Database (Denmark)
Kuroda, M.; Tvergaard, Viggo
2008-01-01
Recently, several higher-order extensions to the crystal plasticity theory have been proposed to incorporate effects of material length scales that were missing links in the conventional continuum mechanics. The extended theories are classified into work-conjugate and non-work-conjugate types. A ...... deformation. In this paper, the discussion is extended to a more general situation, i.e. the context of multiple and three-dimensional slip deformations....
On higher-order corrections in M theory
International Nuclear Information System (INIS)
Howe, P.S.; Tsimpis, D.
2003-01-01
A theoretical analysis of higher-order corrections to D=11 supergravity is given in a superspace framework. It is shown that any deformation of D=11 supergravity for which the lowest-dimensional component of the four-form G 4 vanishes is trivial. This implies that the equations of motion of D=11 supergravity are specified by an element of a certain spinorial cohomology group and generalises previous results obtained using spinorial or pure spinor cohomology to the fully non-linear theory. The first deformation of the theory is given by an element of a different spinorial cohomology group with coefficients which are local tensorial functions of the massless supergravity fields. The four-form Bianchi Identities are solved, to first order and at dimension -{1/2}, in the case that the lowest-dimensional component of G 4 is non-zero. Moreover, it is shown how one can calculate the first-order correction to the dimension-zero torsion and thus to the supergravity equations of motion given an explicit expression for this object in terms of the supergravity fields. The version of the theory with both a four-form and a seven-form is discussed in the presence of the five-brane anomaly-cancelling term. It is shown that the supersymmetric completion of this term exists and it is argued that it is the unique anomaly-cancelling invariant at this dimension which is at least quartic in the fields. This implies that the first deformation of the theory is completely determined by the anomaly term from which one can, in principle, read off the corrections to all of the superspace field strength tensors. (author)
Threshold resummation and higher order effects in QCD
International Nuclear Information System (INIS)
Ringer, Felix Maximilian
2015-01-01
Quantum chromodynamics (QCD) is a quantum field theory that describes the strong interactions between quarks and gluons, the building blocks of all hadrons. Thanks to the experimental progress over the past decades, there has been an ever-growing need for QCD precision calculations for scattering processes involving hadrons. For processes at large momentum transfer, perturbative QCD offers a systematic approach for obtaining precise predictions. This approach relies on two key concepts: the asymptotic freedom of QCD and factorization. In a perturbative calculation at higher orders, the infrared cancellation between virtual and real emission diagrams generally leaves behind logarithmic contributions. In many observables relevant for hadronic scattering these logarithms are associated with a kinematic threshold and are hence known as ''threshold logarithms''. They become large when the available phase space for real gluon emission shrinks. In order to obtain a reliable prediction from QCD, the threshold logarithms need to be taken into account to all orders in the strong coupling constant, a procedure known as ''threshold resummation''. The main focus of my PhD thesis is on studies of QCD threshold resummation effects beyond the next-to-leading logarithmic order. Here we primarily consider the production of hadron pairs in hadronic collisions as an example. In addition, we also consider hadronic jet production, which is particularly interesting for the phenomenology at the LHC. For both processes, we fully take into account the non-trivial QCD color structure of the underlying partonic hard- scattering cross sections. We find that threshold resummation leads to sizable numerical effects in the kinematic regimes relevant for comparisons to experimental data.
1957-2007: 50 Years of Higher Order Programming Languages
Directory of Open Access Journals (Sweden)
Alen Lovrenčić
2009-06-01
Full Text Available Fifty years ago one of the greatest breakthroughs in computer programming and in the history of computers happened -- the appearance of FORTRAN, the first higher-order programming language. From that time until now hundreds of programming languages were invented, different programming paradigms were defined, all with the main goal to make computer programming easier and closer to as many people as possible. Many battles were fought among scientists as well as among developers around concepts of programming, programming languages and paradigms. It can be said that programming paradigms and programming languages were very often a trigger for many changes and improvements in computer science as well as in computer industry. Definitely, computer programming is one of the cornerstones of computer science.Today there are many tools that give a help in the process of programming, but there is still a programming tasks that can be solved only manually. Therefore, programming is still one of the most creative parts of interaction with computers.Programmers should chose programming language in accordance to task they have to solve, but very often, they chose it in accordance to their personal preferences, their beliefs and many other subjective reasons.Nevertheless, the market of programming languages can be merciless to languages as history was merciless to some people, even whole nations. Programming languages and developers get born, live and die leaving more or less tracks and successors, and not always the best survives. The history of programming languages is closely connected to the history of computers and computer science itself. Every single thing from one of them has its reflexions onto the other. This paper gives a short overview of last fifty years of computer programming and computer programming languages, but also gives many ideas that influenced other aspects of computer science. Particularly, programming paradigms are described, their
Higher order energy transfer. Quantum electrodynamical calculations and graphical representation
International Nuclear Information System (INIS)
Jenkins, R.D.
2000-01-01
In Chapter 1, a novel method of calculating quantum electrodynamic amplitudes is formulated using combinatorial theory. This technique is used throughout instead of conventional time-ordered methods. A variety of hyperspaces are discussed to highlight isomorphism between a number of A generalisation of Pascal's triangle is shown to be beneficial in determining the form of hyperspace graphs. Chapter 2 describes laser assisted resonance energy transfer (LARET), a higher order perturbative contribution to the well-known process resonance energy transfer, accommodating an off resonance auxiliary laser field to stimulate the migration. Interest focuses on energy exchanges between two uncorrelated molecular species, as in a system where molecules are randomly oriented. Both phase-weighted and standard isotropic averaging are required for the calculations. Results are discussed in terms of a laser intensity-dependent mechanism. Identifying the applied field regime where LARET should prove experimentally significant, transfer rate increases of up to 30% are predicted. General results for three-center energy transfer are elucidated in chapter 3. Cooperative and accretive mechanistic pathways are identified with theory formulated to elicit their role in a variety of energy transfer phenomena and their relative dominance. In multichromophoric the interplay of such factors is analysed with regard to molecular architectures. The alignments and magnitudes of donor and acceptor transition moments and polarisabilities prove to have profound effects on achievable pooling efficiency for linear configurations. Also optimum configurations are offered. In ionic lattices, although both mechanisms play significant roles in pooling and cutting processes, only the accretive is responsible for sensitisation. The local, microscopic level results are used to gauge the lattice response, encompassing concentration and structural effects. (author)
Preparation and characterization of stable aqueous higher-order fullerenes
International Nuclear Information System (INIS)
Aich, Nirupam; Flora, Joseph R V; Saleh, Navid B
2012-01-01
Stable aqueous suspensions of nC 60 and individual higher fullerenes, i.e. C 70 , C 76 and C 84 , are prepared by a calorimetric modification of a commonly used liquid–liquid extraction technique. The energy requirement for synthesis of higher fullerenes has been guided by molecular-scale interaction energy calculations. Solubilized fullerenes show crystalline behavior by exhibiting lattice fringes in high resolution transmission electron microscopy images. The fullerene colloidal suspensions thus prepared are stable with a narrow distribution of cluster radii (42.7 ± 0.8 nm, 46.0 ± 14.0 nm, 60 ± 3.2 nm and 56.3 ± 1.1 nm for nC 60 , nC 70 , nC 76 and nC 84 , respectively) as measured by time-resolved dynamic light scattering. The ζ-potential values for all fullerene samples showed negative surface potentials with similar magnitude ( − 38.6 ± 5.8 mV, − 39.1 ± 4.2 mV, − 38.9 ± 5.8 mV and − 41.7 ± 5.1 mV for nC 60 , nC 70 , nC 76 and nC 84 , respectively), which provide electrostatic stability to the colloidal clusters. This energy-based modified solubilization technique to produce stable aqueous fullerenes will likely aid in future studies focusing on better applicability, determination of colloidal properties, and understanding of environmental fate, transport and toxicity of higher-order fullerenes. (paper)
Monfrance, Maurice J. M.; Schuit, Ewoud; Groenwold, Rolf H.; Oudijk, Martijn A.; de Graaf, Irene M.; Bax, Caroline J.; Bekedam, Dick J.; Mol, Ben Willem; Langenveld, Josje
2016-01-01
In asymptomatic women with a multiple pregnancy and short cervix prophylactic use of a cervical pessary might reduce preterm birth. We assessed the possible treatment effects of pessary use in pregnancy duration and for poor perinatal outcome. This cohort study was performed between December 2012
Monfrance, Maurice J M; Schuit, Ewoud; Groenwold, Rolf H; Oudijk, Martijn A; de Graaf, Irene M; Bax, Caroline J; Bekedam, Dick J; Mol, Ben Willem; Langenveld, Josje
OBJECTIVE: In asymptomatic women with a multiple pregnancy and short cervix prophylactic use of a cervical pessary might reduce preterm birth. We assessed the possible treatment effects of pessary use in pregnancy duration and for poor perinatal outcome. STUDY DESIGN: This cohort study was performed
[Fertility treatments: possibilities for fewer multiple births and lower costs--the 'Umbrella' study
Merkus, J.M.W.M.
2006-01-01
Since the 1980s, increasingly more fertility treatments have been performed in the Netherlands. The use of ovarian hyperstimulation during in vitro fertilisation (IVF) and intrauterine insemination (IUI) has contributed to an explosive increase in the number of multiple births. To control the costs
Preterm birth in singleton and multiple pregnancies : evaluation of costs and perinatal outcomes
van Baaren, Gert J.; Peelen, Myrthe J. C. S.; Schuit, Ewoud; van der Post, Joris A. M.; Mol, Ben W. J.; Kok, Marjolein; Hajenius, Petra J.
Objective: To estimate costs of preterm birth in singleton and multiple pregnancies. Study design: Cost analysis based on data from a prospective cohort study and three multicentre randomised controlled trials (2006-2012) in a Dutch nationwide consortium for women's health research. Women with
Variations in Multiple Birth Rates and Impact on Perinatal Outcomes in Europe.
Directory of Open Access Journals (Sweden)
Anna Heino
Full Text Available Infants from multiple pregnancies have higher rates of preterm birth, stillbirth and neonatal death and differences in multiple birth rates (MBR exist between countries. We aimed to describe differences in MBR in Europe and to investigate the impact of these differences on adverse perinatal outcomes at a population level.We used national aggregate birth data on multiple pregnancies, maternal age, gestational age (GA, stillbirth and neonatal death collected in the Euro-Peristat project (29 countries in 2010, N = 5 074 643 births. We also used European Society of Human Reproduction and Embryology (ESHRE data on assisted conception and single embryo transfer (SET. The impact of MBR on outcomes was studied using meta-analysis techniques with random-effects models to derive pooled risk ratios (pRR overall and for four groups of country defined by their MBR. We computed population attributable risks (PAR for these groups.In 2010, the average MBR was 16.8 per 1000 women giving birth, ranging from 9.1 (Romania to 26.5 (Cyprus. Compared to singletons, multiples had a nine-fold increased risk (pRR 9.4, 95% Cl 9.1-9.8 of preterm birth (<37 weeks GA, an almost 12-fold increased risk (pRR 11.7, 95% CI 11.0-12.4 of very preterm birth (<32 weeks GA. Pooled RR were 2.4 (95% Cl 1.5-3.6 for fetal mortality at or after 28 weeks GA and 7.0 (95% Cl 6.1-8.0 for neonatal mortality. PAR of neonatal death and very preterm birth were higher in countries with high MBR compared to low MBR (17.1% (95% CI 13.8-20.2 versus 9.8% (95% Cl 9.6-11.0 for neonatal death and 29.6% (96% CI 28.5-30.6 versus 17.5% (95% CI 15.7-18.3 for very preterm births, respectively.Wide variations in MBR and their impact on population outcomes imply that efforts by countries to reduce MBR could improve perinatal outcomes, enabling better long-term child health.
Knopik, Valerie S.; Marceau, Kristine; Palmer, Rohan H. C.; Smith, Taylor F.; Heath, Andrew C.
2016-01-01
Maternal smoking during pregnancy (SDP) is a significant public health concern with adverse consequences to the health and well-being of the fetus. There is considerable debate about the best method of assessing SDP, including birth/medical records, timeline follow-back approaches, multiple reporters, and biological verification (e.g., cotinine). This is particularly salient for genetically-informed approaches where it is not always possible or practical to do a prospective study starting during the prenatal period when concurrent biological specimen samples can be collected with ease. In a sample of families (N = 173) specifically selected for sibling pairs discordant for prenatal smoking exposure, we: (1) compare rates of agreement across different types of report—maternal report of SDP, paternal report of maternal SDP, and SDP contained on birth records from the Department of Vital Statistics; (2) examine whether SDP is predictive of birth weight outcomes using our best SDP report as identified via step (1); and (3) use a sibling-comparison approach that controls for genetic and familial influences that siblings share in order to assess the effects of SDP on birth weight. Results show high agreement between reporters and support the utility of retrospective report of SDP. Further, we replicate a causal association between SDP and birth weight, wherein SDP results in reduced birth weight even when accounting for genetic and familial confounding factors via a sibling comparison approach. PMID:26494459
Higher Order Spike Synchrony in Prefrontal Cortex during visual memory
Directory of Open Access Journals (Sweden)
Gordon ePipa
2011-06-01
Full Text Available Precise temporal synchrony of spike firing has been postulated as an important neuronal mechanism for signal integration and the induction of plasticity in neocortex. As prefrontal cortex plays an important role in organizing memory and executive functions, the convergence of multiple visual pathways onto PFC predicts that neurons should preferentially synchronize their spiking when stimulus information is processed. Furthermore, synchronous spike firing should intensify if memory processes require the induction of neuronal plasticity, even if this is only for short-term. Here we show with multiple simultaneously recorded units in ventral prefrontal cortex that neurons participate in 3 ms precise synchronous discharges distributed across multiple sites separated by at least 500 µm. The frequency of synchronous firing is modulated by behavioral performance and is specific for the memorized visual stimuli. In particular, during the memory period in which activity is not stimulus driven, larger groups of up to 7 sites exhibit performance dependent modulation of their spike synchronization.
Analysis of wheezes using wavelet higher order spectral features.
Taplidou, Styliani A; Hadjileontiadis, Leontios J
2010-07-01
. This paves the way for the use of the wavelet higher order spectral features as an input vector to an efficient classifier. Apparently, this would integrate the intrinsic characteristics of wheezes within computerized diagnostic tools toward their more efficient evaluation.
Higher-order aberrations and visual acuity after LASEK.
Urgancioglu, Berrak; Bilgihan, Kamil; Ozturk, Sertac
2008-08-01
To determine ocular higher-order aberrations (HOAs) in eyes with supernormal vision after myopic astigmatic laser subepithelial keratomileusis (LASEK) and to compare the findings with those in eyes with natural supernormal vision. Ocular HOAs were measured after LASEK in 20 eyes of 12 myopic astigmatic patients with postoperative uncorrected visual acuity (UCVA) of >20/16 (group 1). Patients who were included in the study had no visual symptoms like glare, halo or double vision. The measurements were taken 8.3 +/- 3 months after LASEK surgery. In group 2 ocular HOAs were examined in 20 eyes of 10 subjects with natural UCVA of >20/16 as a control. Measurements were taken across a pupil with a diameter of 4.0 mm and 6.0 mm. Root-mean-square (RMS) values of HOAs, Z(3)-1, Z(3)1, Z(4)0, Z(5)-1, Z(5)1 and Z(6)0 were analyzed. The mean RMS values for each order were higher in group 1 when compared with group 2 at 4.0 mm and 6.0 mm pupil diameters. There was no statistically significant difference between groups in spherical and coma aberrations (P > 0.05). Mean RMS values for total HOAs were 0.187 +/- 0.09 microm at 4.0 mm and 0.438 +/- 0.178 microm at 6.0 mm pupil in group 1 and 0.120 +/- 0.049 microm at 4.0 mm and 0.344 +/- 0.083 microm at 6.0 mm pupil in group 2. The difference between groups in total HOAs was statistically significant at 4.0 mm and 6.0 mm pupil diameters (P < 0.05). Ocular HOAs exist in eyes with supernormal vision. After LASEK, the amount of HOAs of the eye increases under both mesopic and photopic conditions. However the amount of HOA increase does not seem to be consistent with visual symptoms.
Dynamics and phenomenology of higher order gravity cosmological models
Moldenhauer, Jacob Andrew
2010-10-01
I present here some new results about a systematic approach to higher-order gravity (HOG) cosmological models. The HOG models are derived from curvature invariants that are more general than the Einstein-Hilbert action. Some of the models exhibit late-time cosmic acceleration without the need for dark energy and fit some current observations. The open question is that there are an infinite number of invariants that one could select, and many of the published papers have stressed the need to find a systematic approach that will allow one to study methodically the various possibilities. We explore a new connection that we made between theorems from the theory of invariants in general relativity and these cosmological models. In summary, the theorems demonstrate that curvature invariants are not all independent from each other and that for a given Ricci Segre type and Petrov type (symmetry classification) of the space-time, there exists a complete minimal set of independent invariants (a basis) in terms of which all the other invariants can be expressed. As an immediate consequence of the proposed approach, the number of invariants to consider is dramatically reduced from infinity to four invariants in the worst case and to only two invariants in the cases of interest, including all Friedmann-Lemaitre-Robertson-Walker metrics. We derive models that pass stability and physical acceptability conditions. We derive dynamical equations and phase portrait analyses that show the promise of the systematic approach. We consider observational constraints from magnitude-redshift Supernovae Type Ia data, distance to the last scattering surface of the Cosmic Microwave Background radiation, and Baryon Acoustic Oscillations. We put observational constraints on general HOG models. We constrain different forms of the Gauss-Bonnet, f(G), modified gravity models with these observations. We show some of these models pass solar system tests. We seek to find models that pass physical and
A Higher-Order Neural Network Design for Improving Segmentation Performance in Medical Image Series
International Nuclear Information System (INIS)
Selvi, Eşref; Selver, M Alper; Güzeliş, Cüneyt; Dicle, Oǧuz
2014-01-01
Segmentation of anatomical structures from medical image series is an ongoing field of research. Although, organs of interest are three-dimensional in nature, slice-by-slice approaches are widely used in clinical applications because of their ease of integration with the current manual segmentation scheme. To be able to use slice-by-slice techniques effectively, adjacent slice information, which represents likelihood of a region to be the structure of interest, plays critical role. Recent studies focus on using distance transform directly as a feature or to increase the feature values at the vicinity of the search area. This study presents a novel approach by constructing a higher order neural network, the input layer of which receives features together with their multiplications with the distance transform. This allows higher-order interactions between features through the non-linearity introduced by the multiplication. The application of the proposed method to 9 CT datasets for segmentation of the liver shows higher performance than well-known higher order classification neural networks
Multilevel Higher-Order Item Response Theory Models
Huang, Hung-Yu; Wang, Wen-Chung
2014-01-01
In the social sciences, latent traits often have a hierarchical structure, and data can be sampled from multiple levels. Both hierarchical latent traits and multilevel data can occur simultaneously. In this study, we developed a general class of item response theory models to accommodate both hierarchical latent traits and multilevel data. The…
Quantifying the impact of scholarly papers based on higher-order weighted citations.
Bai, Xiaomei; Zhang, Fuli; Hou, Jie; Lee, Ivan; Kong, Xiangjie; Tolba, Amr; Xia, Feng
2018-01-01
Quantifying the impact of a scholarly paper is of great significance, yet the effect of geographical distance of cited papers has not been explored. In this paper, we examine 30,596 papers published in Physical Review C, and identify the relationship between citations and geographical distances between author affiliations. Subsequently, a relative citation weight is applied to assess the impact of a scholarly paper. A higher-order weighted quantum PageRank algorithm is also developed to address the behavior of multiple step citation flow. Capturing the citation dynamics with higher-order dependencies reveals the actual impact of papers, including necessary self-citations that are sometimes excluded in prior studies. Quantum PageRank is utilized in this paper to help differentiating nodes whose PageRank values are identical.
Quantifying the impact of scholarly papers based on higher-order weighted citations
Bai, Xiaomei; Zhang, Fuli; Hou, Jie; Kong, Xiangjie; Tolba, Amr; Xia, Feng
2018-01-01
Quantifying the impact of a scholarly paper is of great significance, yet the effect of geographical distance of cited papers has not been explored. In this paper, we examine 30,596 papers published in Physical Review C, and identify the relationship between citations and geographical distances between author affiliations. Subsequently, a relative citation weight is applied to assess the impact of a scholarly paper. A higher-order weighted quantum PageRank algorithm is also developed to address the behavior of multiple step citation flow. Capturing the citation dynamics with higher-order dependencies reveals the actual impact of papers, including necessary self-citations that are sometimes excluded in prior studies. Quantum PageRank is utilized in this paper to help differentiating nodes whose PageRank values are identical. PMID:29596426
Effect of multiple micronutrient supplementation during pregnancy on maternal and birth outcomes
Directory of Open Access Journals (Sweden)
Yakoob Mohammad
2011-04-01
Full Text Available Abstract Objectives/background Given the widespread prevalence of micronutrient deficiencies in developing countries, supplementation with multiple micronutrients rather than iron-folate alone, could be of potential benefit to the mother and the fetus. These benefits could relate to prevention of maternal complications and reduction in other adverse pregnancy outcomes such as small-for-gestational age (SGA births, low birth weight, stillbirths, perinatal and neonatal mortality. This review evaluates the evidence of the impact of multiple micronutrient supplements during pregnancy, in comparison with standard iron-folate supplements, on specific maternal and pregnancy outcomes of relevance to the Lives Saved Tool (LiST. Data sources/review methods A systematic review of randomized controlled trials was conducted. Search engines used were PubMed, the Cochrane Library, the WHO regional databases and hand search of bibliographies. A standardized data abstraction and Child Health Epidemiology Reference (CHERG adaptation of the Grading of Recommendations Assessment, Development and Evaluation (GRADE technique were used for data abstraction and overall quality of evidence. Meta-analyses were performed to calculate summary estimates of utility to the LiST model for the specified outcome of incidence of SGA births. We also evaluated the potential impact of multiple micronutrients on neonatal mortality according to the proportion of deliveries occurring in facilities (using a threshold of 60% to indicate functionality of health systems for skilled births. Results We included 17 studies for detailed data abstraction. There was no significant benefit of multiple micronutrients as compared to iron folate on maternal anemia in third trimester [Relative risk (RR = 1.03; 95% confidence interval (CI: 0.87 – 1.22 (random model]. Our analysis, however, showed a significant reduction in SGA by 9% [RR = 0.91; 95% CI: 0.86 – 0.96 (fixed model]. In the fixed model
An efficient higher order family of root finders
Petkovic, Ljiljana D.; Rancic, Lidija; Petkovic, Miodrag S.
2008-06-01
A one parameter family of iterative methods for the simultaneous approximation of simple complex zeros of a polynomial, based on a cubically convergent Hansen-Patrick's family, is studied. We show that the convergence of the basic family of the fourth order can be increased to five and six using Newton's and Halley's corrections, respectively. Since these corrections use the already calculated values, the computational efficiency of the accelerated methods is significantly increased. Further acceleration is achieved by applying the Gauss-Seidel approach (single-step mode). One of the most important problems in solving nonlinear equations, the construction of initial conditions which provide both the guaranteed and fast convergence, is considered for the proposed accelerated family. These conditions are computationally verifiable; they depend only on the polynomial coefficients, its degree and initial approximations, which is of practical importance. Some modifications of the considered family, providing the computation of multiple zeros of polynomials and simple zeros of a wide class of analytic functions, are also studied. Numerical examples demonstrate the convergence properties of the presented family of root-finding methods.
Optical MSD symbolic substitution system based on a higher ordered rule
Reddy, A. K.; Mallikarjun, Tatipamula; Raina, J. P.
1992-12-01
The advantages provided by Photonic Computing has been well documented. An Optical arithmetic processor has to take full advantage of the massive parallelism in optical signals. Such a processor, using the Modified - Signed - Digit (MSD) number . (i) representation, has been presented here based (2) on the symbolic substitution 1ogi. The higher order symbolic substitution rules are formulated for the addition operation, which is carried out in just two steps. Based on the addition operation, the other arithmetic operations - subtraction, multiplication and division - are implemented. Finally, the usefulness of this MSD system is studied.
Directory of Open Access Journals (Sweden)
Peng Li
2016-10-01
Full Text Available This article proposes an adaptive multivariable higher-order sliding mode control for the longitudinal model of an air-breathing vehicle under system uncertainties and actuator failures. Firstly, a fast finite-time control law is designed for a chain of integrators. Secondly, based on the input/output feedback linearization technique, the system uncertainty and external disturbances are modeled as additive certainty and the actuator failures are modeled as multiplicative uncertainty. By using the proposed fast finite-time control law, a robust multivariable higher-order sliding mode control is designed for the air-breathing hypersonic vehicle with actuator failures. Finally, adaptive laws are proposed for the adaptation of the parameters in the robust multivariable higher-order sliding mode control. Thus, the bounds of the uncertainties are not needed in the control system design. Simulation results show the effectiveness of the proposed robust adaptive multivariable higher-order sliding mode control.
Methodological and hermeneutic reduction - a study of Finnish multiple-birth families.
Heinonen, Kristiina
2015-07-01
To describe reduction as a method in methodological and hermeneutic reduction and the hermeneutic circle using van Manen's principles, with the empirical example of the lifeworlds of multiple-birth families in Finland. Reduction involves several levels that can be distinguished for their methodological usefulness. Researchers can use reduction in different ways and dimensions for their methodological needs. Open interviews with public health nurses, family care workers and parents of twins. The systematic literature and knowledge review shows there were no articles on multiple-birth families that used van Manen's method. This paper presents reduction as a method that uses the hermeneutic circle. The lifeworlds of multiple-birth families consist of three core themes: 'A state of constant vigilance'; 'Ensuring that they can continue to cope'; and 'Opportunities to share with other people'. Reduction allows us to perform deep phenomenological-hermeneutic research and understand people's lifeworlds. It helps to keep research stages separate but also enables a consolidated view. Social care and healthcare professionals have to hear parents' voices better to comprehensively understand their situation; they also need further tools and training to be able to empower parents of twins. The many variations in adapting reduction mean its use can be very complex and confusing. This paper adds to the discussion of phenomenology, hermeneutic study and reduction.
Rodríguez Fonollosa, Javier; Nikias, Chrysostomos L.
1993-01-01
The Wigner higher order moment spectra (WHOS) are defined as extensions of the Wigner-Ville distribution (WD) to higher order moment spectra domains. A general class of time-frequency higher order moment spectra is also defined in terms of arbitrary higher order moments of the signal as generalizations of the Cohen’s general class of time-frequency representations. The properties of the general class of time-frequency higher order moment spectra can be related to the properties...
Month of birth as a latitude-dependent risk factor for multiple sclerosis in Norway.
Grytten, Nina; Torkildsen, Øivind; Aarseth, Jan Harald; Benjaminsen, Espen; Celius, Elisabeth Gulowsen; Dahl, Ole Petter; Holmøy, Trygve; Løken-Amsrud, Kristin; Midgard, Rune; Myhr, Kjell-Morten; Risberg, Geir; Vatne, Anita; Kampman, Margitta T
2013-07-01
We aimed to determine if the risk of Multiple Sclerosis (MS) is associated with month of birth in Norway and to explore a possible latitudinal gradient. All patients with MS born between 1930 and 1979 registered in the Norwegian MS Registry or ascertained in Norwegian prevalence studies were included (n = 6649). The latitude gradient was divided in Southern, Middle and Northern Norway, according to the estimated regional yearly mean vitamin D effective UV dose. Risk of MS was 11% higher for those born in April (p = 0.045), and 5% higher for those born in May (p = 0.229), 5% lower for those born in November (p = 0.302) and 12% lower for those born in February (p = 0.053) compared with the corresponding population, unaffected mothers and siblings. In Southern Norway the odds ratio of MS births in April and May was 1.05 (0.98-1.24), in Middle Norway 1.11 (0.97-1.27) and in Northern Norway 1.28 (1.0-1.63) compared with the other months. This study confirms previous reports of increased MS births in spring and decreased MS births in the winter months. This could support the role of decreased sunlight exposure during pregnancy and vitamin D deficiency in prenatal life in MS.
Lim, A. C.; Hegeman, M. A. [=Maud A.; Huis In 't Veld, M. A.; Opmeer, B. C.; Bruinse, H. W.; Mol, B. W. J.
2011-01-01
To review the literature on cervical length as a predictor of preterm birth in asymptomatic women with a multiple pregnancy. We searched MEDLINE, Embase and reference lists of included articles to identify all studies that reported on the accuracy of cervical length for predicting preterm birth in
[Retinopathy of prematurity in multiple births: risk analysis for plus disease].
García-Serrano, J L; Ramírez-García, M C; Piñar-Molina, R
2009-04-01
To analyze the risk factors associated with plus disease in retinopathy of prematurity (ROP). Over a period of 8.5 years we carried out a prospective study of ROP in twins and triplets. Fifty-four multiple-birth infants with low birth weight (large area of avascular retina, low gestational age, low birth weight, a patent ductus arteriosus, length of mechanical ventilation, adverse events increase, low 5 min Apgar scores and poor postnatal weight gain (in the first 4 to 6 weeks of life). Using multiple logistic regression, only the grade of ROP (OR: 5.5; p disease gained an average 3.9 +/- 3.1 g/day in the first 6 weeks of life, compared to a mean of 11.84 +/- 8.3 g/day for those without plus disease (p < 0.0001). Advanced ROP stages and poor weight gain were the most significant factors associated with plus disease. Twins who gained weight at more than 7 g/day in the first 4-6 weeks of life had a significantly reduced risk of plus disease. A good weight gain is an effective strategy against avoidable blindness due to ROP.
Mantel, Bruno; Stoffregen, Thomas A.; Campbell, Alain; Bardy, Benoît G.
2015-01-01
Body movement influences the structure of multiple forms of ambient energy, including optics and gravito-inertial force. Some researchers have argued that egocentric distance is derived from inferential integration of visual and non-visual stimulation. We suggest that accurate information about egocentric distance exists in perceptual stimulation as higher-order patterns that extend across optics and inertia. We formalize a pattern that specifies the egocentric distance of a stationary object across higher-order relations between optics and inertia. This higher-order parameter is created by self-generated movement of the perceiver in inertial space relative to the illuminated environment. For this reason, we placed minimal restrictions on the exploratory movements of our participants. We asked whether humans can detect and use the information available in this higher-order pattern. Participants judged whether a virtual object was within reach. We manipulated relations between body movement and the ambient structure of optics and inertia. Judgments were precise and accurate when the higher-order optical-inertial parameter was available. When only optic flow was available, judgments were poor. Our results reveal that participants perceived egocentric distance from the higher-order, optical-inertial consequences of their own exploratory activity. Analysis of participants’ movement trajectories revealed that self-selected movements were complex, and tended to optimize availability of the optical-inertial pattern that specifies egocentric distance. We argue that accurate information about egocentric distance exists in higher-order patterns of ambient energy, that self-generated movement can generate these higher-order patterns, and that these patterns can be detected and used to support perception of egocentric distance that is precise and accurate. PMID:25856410
Accounting for multiple births in neonatal and perinatal trials: systematic review and case study.
Hibbs, Anna Maria; Black, Dennis; Palermo, Lisa; Cnaan, Avital; Luan, Xianqun; Truog, William E; Walsh, Michele C; Ballard, Roberta A
2010-02-01
To determine the prevalence in the neonatal literature of statistical approaches accounting for the unique clustering patterns of multiple births and to explore the sensitivity of an actual trial to several analytic approaches to multiples. A systematic review of recent perinatal trials assessed the prevalence of studies accounting for clustering of multiples. The Nitric Oxide to Prevent Chronic Lung Disease (NO CLD) trial served as a case study of the sensitivity of the outcome to several statistical strategies. We calculated odds ratios using nonclustered (logistic regression) and clustered (generalized estimating equations, multiple outputation) analyses. In the systematic review, most studies did not describe the random assignment of twins and did not account for clustering. Of those studies that did, exclusion of multiples and generalized estimating equations were the most common strategies. The NO CLD study included 84 infants with a sibling enrolled in the study. Multiples were more likely than singletons to be white and were born to older mothers (P accounted for clustering were statistically significant; analyses assuming independence were not. The statistical approach to multiples can influence the odds ratio and width of confidence intervals, thereby affecting the interpretation of a study outcome. A minority of perinatal studies address this issue. Copyright 2010 Mosby, Inc. All rights reserved.
Roca de Bes, Montserrat; Gutierrez Maldonado, José; Gris Martínez, José M
2009-09-01
To determine the psychosocial risks associated with multiple births (twins or triplets) resulting from assisted reproductive technology (ART). Transverse study. Infertility units of a university hospital and a private hospital. Mothers and fathers of children between 6 months and 4 years conceived by ART (n = 123). The sample was divided into three groups: parents of singletons (n = 77), twins (n = 37), and triplets (n = 9). The questionnaire was self-administered by patients. It was either completed at the hospital or mailed to participants' homes. Scales measured material needs, quality of life, social stigma, depression, stress, and marital satisfaction. Logistic regression models were applied. Significant odds ratios were obtained for the number of children, material needs, social stigma, quality of life, and marital satisfaction. The results were more significant for data provided by mothers than by fathers. The informed consent form handed out at the beginning of ART should include information on the high risk of conceiving twins and triplets and on the possible psychosocial consequences of multiple births. As soon as a multiple pregnancy is confirmed, it would be useful to provide information on support groups and institutions. Psychological advice should also be given to the parents.
Directory of Open Access Journals (Sweden)
Uma M Sundhararaj
2017-01-01
Full Text Available Background: Historically, to achieve higher pregnancy rates, multiple embryos were transferred after an in-vitro fertilisation (IVF. However, this practice is being reassessed, because it leads to multiple pregnancies that is known to cause adverse maternal and fetal outcomes. Aim: To compare the pregnancy outcomes in fresh IVF or intracytoplasmic sperm injection (ICSI cycles among women undergoing elective single blastocyst transfer (eSBT vs. those undergoing double blastocyst transfer (DBT. Settings and Design: It is a retrospective data analysis of 582 patients undergoing fresh IVF/ICSI cycles performed from January 2012 to June 2015. Materials and Methods: Patients, who underwent IVF/ICSI and developed more than one blastocyst, were included in the study. Donor cycles were excluded from the study. All the embryos were cultured to blastocyst stage in sequential media followed by transfer of two blastocysts (DBT or eSBT and cryopreservation of the remaining. Statistical Analysis: Statistical analysis was performed using chi square test. Results: Out of 582 patients, in 149 patients one blastocyst was transferred and in 433 patients two blastocysts were transferred. There was no statistical difference in the biochemical pregnancy rate, clinical pregnancy rate and live birth rate in both the groups. Statistics demonstrated a significant drop in miscarriage rate in eSBT group. There was no incidence of twins in eSBT group, whereas twin birth rate per clinical pregnancy was 29.02% in DBT group. Conclusion: Single blastocyst transfer is an effective method to reduce the risk of multiple births without compromising the pregnancy outcomes. Given the promising potential of vitrification; the remaining blastocyst can be cryopreserved.
The Meaning of Higher-Order Factors in Reflective-Measurement Models
Eid, Michael; Koch, Tobias
2014-01-01
Higher-order factor analysis is a widely used approach for analyzing the structure of a multidimensional test. Whenever first-order factors are correlated researchers are tempted to apply a higher-order factor model. But is this reasonable? What do the higher-order factors measure? What is their meaning? Willoughby, Holochwost, Blanton, and Blair…
On the expressiveness and decidability of higher-order process calculi
Lanese, Ivan; Perez, Jorge A.; Sangiorgi, Davide; Schmitt, Alan
In higher-order process calculi, the values exchanged in communications may contain processes. A core calculus of higher-order concurrency is studied; it has only the operators necessary to express higher-order communications: input prefix, process output, and parallel composition. By exhibiting a
Analysis of Buried Dielectric Objects Using Higher-Order MoM for Volume Integral Equations
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav
2004-01-01
A higher-order method of moments (MoM) is applied to solve a volume integral equation for dielectric objects in layered media. In comparison to low-order methods, the higher-order MoM, which is based on higher-order hierarchical Legendre vector basis functions and curvilinear hexahedral elements,...
Missed epidemics and missing links: international birth cohort trends in multiple sclerosis.
Ajdacic-Gross, V; Tschopp, A; Schmid, M; Bopp, M; Gutzwiller, F
2013-03-01
Many hypotheses on the etiopathogenesis of multiple sclerosis (MS) focus on risk factors occurring early in life. This study examined the variability of birth cohort trends in international MS data by means of age-period-cohort (APC) analysis. The data from 25 countries were taken from the WHO mortality database. Data were encoded according to the International Classification of Diseases and covered slightly varying periods between 1951 and 2009. The APC analyses were based on logit models applied to cohort tables with 5-year age- and period intervals. In most countries, the birth cohort estimates peaked in those born in the first half of the 20th century. In countries from Central and Western Europe, the peak concerned those born before and around 1920. A second group of countries (Denmark, Sweden, Italy, Ireland, Scotland) shared a later peak amongst cohorts born in the 1920s and 1930s. Group 3 included Commonwealth countries, the USA and Norway, with a double or extended peak starting in the 1910s or 1920s, and ending by the 1950s. The fourth group, consisting of Mediterranean countries and Finland, was characterized by a steady increase in the birth cohort estimates until the 1950s. The fifth group with countries from Eastern Europe and Japan showed no particular pattern. Birth cohort trends have influenced the change in MS risk across the 20th century in many Western countries. This silent epidemic points to a most important but unknown latent risk factor in MS. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.
Sang Ho Kim; Dong O Jeon; Sundeli, R
2002-01-01
In linacs for intense pulsed proton accelerators, the beam has a multiple time-structure, and each beam time-structure generates resonance. When a higher-order mode (HOM) is near these resonance frequencies, the induced voltage could be large and accordingly the resulting HOM power, too. In order to understand the effects of a complex beam time-structure on the mode excitations and the resulting HOM powers in elliptical superconducting cavities, analytic expressions are developed, with which the beam-induced voltage and corresponding power are explored, taking into account the properties of HOM frequency behavior in elliptical superconducting cavities. The results and understandings from this analysis are presented with the beam parameters of the Spallation Neutron Source (SNS) superconducting linac.
Sombun, S.; Steinheimer, J.; Herold, C.; Limphirat, A.; Yan, Y.; Bleicher, M.
2018-02-01
We study the dependence of the normalized moments of the net-proton multiplicity distributions on the definition of centrality in relativistic nuclear collisions at a beam energy of \\sqrt{{s}{NN}}=7.7 {GeV}. Using the ultra relativistic quantum molecular dynamics model as event generator we find that the centrality definition has a large effect on the extracted cumulant ratios. Furthermore we find that the finite efficiency for the determination of the centrality introduces an additional systematic uncertainty. Finally, we quantitatively investigate the effects of event-pile up and other possible spurious effects which may change the measured proton number. We find that pile-up alone is not sufficient to describe the data and show that a random double counting of events, adding significantly to the measured proton number, affects mainly the higher order cumulants in most central collisions.
Lin, Ju; Li, Jie; Li, Xiaolei; Wang, Ning
2016-10-01
An acoustic reciprocity theorem is generalized, for a smoothly varying perturbed medium, to a hierarchy of reciprocity theorems including higher-order derivatives of acoustic fields. The standard reciprocity theorem is the first member of the hierarchy. It is shown that the conservation of higher-order interaction quantities is related closely to higher-order derivative distributions of perturbed media. Then integral reciprocity theorems are obtained by applying Gauss's divergence theorem, which give explicit integral representations connecting higher-order interactions and higher-order derivative distributions of perturbed media. Some possible applications to an inverse problem are also discussed.
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter
2004-01-01
An efficient higher-order method of moments (MoM) solution of volume integral equations is presented. The higher-order MoM solution is based on higher-order hierarchical Legendre basis functions and higher-order geometry modeling. An unstructured mesh composed of 8-node trilinear and/or curved 27...... of magnitude in comparison to existing higher-order hierarchical basis functions. Consequently, an iterative solver can be applied even for high expansion orders. Numerical results demonstrate excellent agreement with the analytical Mie series solution for a dielectric sphere as well as with results obtained...
Impact of higher-order flows in the moment equations on Pfirsch-Schlüter friction coefficients
Energy Technology Data Exchange (ETDEWEB)
Honda, M., E-mail: honda.mitsuru@jaea.go.jp [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan)
2014-09-15
The impact of the higher-order flows in the moment approach on an estimate of the friction coefficients is numerically examined. The higher-order flows are described by the lower-order hydrodynamic flows using the collisional plasma assumption. Their effects have not been consistently taken into account thus far in the widely used neoclassical transport codes based on the moment equations in terms of the Pfirsch-Schlüter flux. Due to numerically solving the friction-flow matrix without using the small-mass ratio expansion, it is clearly revealed that incorporating the higher-order flow effects is of importance especially for plasmas including multiple hydrogenic ions and other lighter species with similar masses.
The costs to the NHS of multiple births after IVF treatment in the UK.
Ledger, William L; Anumba, Dilly; Marlow, Neil; Thomas, Christine M; Wilson, Edward C F
2006-01-01
To determine the cost to the NHS resulting from multiple pregnancies arising from IVF treatment in the UK, and to compare those costs with the cost to the NHS due to singleton pregnancies resulting from IVF treatment. A modelling study using data from published literature and cost data from national sources in the public domain, calculating direct costs from the diagnosis of a clinical pregnancy until the end of the first year after birth. Academic Unit of Reproductive and Developmental Medicine. Theoretic core modelling study using data from published literature. The analysis was based on the total annual number of births resulting from an IVF treatment in the UK. Main outcome measures total direct costs to the NHS per IVF singleton, twin or triplet family. Cost of singleton, twin and triplet IVF pregnancies in the UK. Total direct costs to the NHS per IVF twin or triplet family (maternal + infant costs) are substantially higher than per IVF singleton family (singleton: pounds 3313; twin: pounds 9122; and triplet: pounds 32,354). Multiple pregnancies after IVF are associated with 56% of the direct cost of IVF pregnancies, although they represent less than 1/3 of the total annual number of maternities in the UK. Multiple pregnancies after IVF are associated with high direct costs to the NHS. Redirection of money saved by implementation of a mandatory 'two embryo transfer' policy into increased provision of IVF treatment could double the number of NHS-funded IVF treatment cycles at no extra cost. Further savings could be made if a selective 'single embryo transfer' policy were to be adopted.
Method of applying single higher order polynomial basis function over multiple domains
CSIR Research Space (South Africa)
Lysko, AA
2010-03-01
Full Text Available . Derivation of the computational complexity in terms of oating point operations (FLOP) showed a possible speed gain nearly an order of the number of unknowns of direct MoM. 1. INTRODUCTION The process of numerical electromagnetic modeling may be split... into several stages [1], including geometry representation/modeling, representation/modeling of the current distribution, solution of the equations, and computation of the radiation and other parameters. A dominant majority of existing theoretical frameworks...
Physical properties of seven binary and higher-order multiple OB systems
Czech Academy of Sciences Publication Activity Database
Mayer, P.; Harmanec, P.; Chini, R.; Nasseri, A.; Nemravová, J.; Drechsel, H.; Catalan-Hurtado, R.; Barlow, B.N.; Kotková, Lenka
2017-01-01
Roč. 600, April (2017), A33/1-A33/15 E-ISSN 1432-0746 R&D Projects: GA MŠk LG14013 Grant - others:GA ČR(CZ) GA15-02112S Institutional support: RVO:67985815 Keywords : spectroscopic * massive stars * fundamental parameters Subject RIV: BN - Astronomy , Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.014, year: 2016
Higher-order associative processing in Hermissenda suggests multiple sites of neuronal modulation.
Rogers, R F; Matzel, L D
1996-01-01
Two important features of modern accounts of associative learning are (1) the capacity for contextual stimuli to serve as a signal for an unconditioned stimulus (US) and (2) the capacity for a previously conditioned (excitatory) stimulus to "block" learning about a redundant stimulus when both stimuli serve as a signal for the same US. Here, we examined the process of blocking, thought by some to reflect a cognitive aspect of classical conditioning, and its underlying mechanisms in the marine mollusc Hermissenda. In two behavioral experiments, a context defined by chemosensory stimuli was made excitatory by presenting unsignalled USs (rotation) in that context. The excitatory context subsequently blocked overt learning about a discrete conditioned stimulus (CS; light) paired with the US in that context. In a third experiment, the excitability of the B photoreceptors in the Hermissenda eye, which typically increases following light-rotation pairings, was examined in behaviorally blocked animals, as well as in animals that had acquired a normal CS-US association or animals that had been exposed to the CS and US unpaired. Both the behaviorally blocked and the "normal" learning groups exhibited increases in neuronal excitability relative to unpaired animals. However, light-induced multiunit activity in pedal nerves was suppressed following normal conditioning but not in blocked or unpaired control animals, suggesting that the expression of blocking is mediated by neuronal modifications not directly reflected in B-cell excitability, possibly within an extensive network of central light-responsive interneurons.
Mathematics Teachers’ Interpretation of Higher-Order Thinking in Bloom’s Taxonomy
Tony Thompson
2008-01-01
This study investigated mathematics teachers’ interpretation of higher-order thinking in Bloom’s Taxonomy. Thirty-two high school mathematics teachers from the southeast U.S. were asked to (a) define lower- and higher-order thinking, (b) identify which thinking skills in Bloom’s Taxonomy represented lower- and higher-order thinking, and (c) create an Algebra I final exam item representative of each thinking skill. Results indicate that mathematics teachers have difficulty interpreting the thi...
PRE-SERVICE MATHEMATICS TEACHERS’ CONCEPTION OF HIGHER-ORDER THINKING LEVEL IN BLOOM'S TAXONOMY
Damianus D Samo
2017-01-01
The purpose of this study is to explore pre-service mathematics teachers' conception of higher-order thinking in Bloom's Taxonomy, to explore pre-service mathematics teachers' ability in categorizing six cognitive levels of Bloom's Taxonomy as lower-order thinking and higher-order thinking, and pre-service mathematics teachers' ability in identifying some questionable items as lower-order and higher-order thinking. The higher-order thinking is the type of non-algorithm thinking which include ...
Analysis and Improvement of the Generic Higher-Order Masking Scheme of FSE 2012
Roy, Arnab; Venkatesh, Srinivas Vivek
2013-01-01
Masking is a well-known technique used to prevent block cipher implementations from side-channel attacks. Higher-order side channel attacks (e.g. higher-order DPA attack) on widely used block cipher like AES have motivated the design of efficient higher-order masking schemes. Indeed, it is known that as the masking order increases, the difficulty of side-channel attack increases exponentially. However, the main problem in higher-order masking is to design an efficient and secure technique for...
Almeida, Joanna; Bécares, Laia; Erbetta, Kristin; Bettegowda, Vani R; Ahluwalia, Indu B
2018-02-13
Introduction Racial/ethnic inequities in low birth weight (LBW) and preterm birth (PTB) persist in the United States. Research has identified numerous risk factors for adverse birth outcomes; however, they do not fully explain the occurrence of, or inequalities in PTB/LBW. Stress has been proposed as one explanation for differences in LBW and PTB by race/ethnicity. Methods Using the Pregnancy Risk Assessment Monitoring System (PRAMS) data from 2012 to 2013 for 21 states and one city (n = 15,915) we used Poisson regression to estimate the association between acute, financial and relationship stressors and LBW and PTB, and to examine the contribution of these stressors individually and simultaneously to racial/ethnic differences in LBW and PTB. Results Adjusting for age and race/ethnicity, acute (p stress increased risk of PTB. Across all models, non-Hispanic blacks had higher risk of LBW and PTB relative to non-Hispanic whites (IRR 1.87, 95% CI 1.55, 2.27 and IRR 1.46, 95% CI 1.18, 1.79). Accounting for the effects of stressors attenuated the risk of LBW and PTB by 17 and 22% respectively, but did not fully explain the increased likelihood of LBW and PTB among non-Hispanic blacks. Discussion Results of this study demonstrate that stress may increase the risk of LBW and PTB. While stressors may contribute to racial/ethnic differences in LBW and PTB, they do not fully explain them. Mitigating stress during pregnancy may help promote healthier birth outcomes and reduce racial/ethnic inequities in LBW and PTB.
Authentic Instruction for 21st Century Learning: Higher Order Thinking in an Inclusive School
Preus, Betty
2012-01-01
The author studied a public junior high school identified as successfully implementing authentic instruction. Such instruction emphasizes higher order thinking, deep knowledge, substantive conversation, and value beyond school. To determine in what ways higher order thinking was fostered both for students with and without disabilities, the author…
Fischer, Christopher; Bol, Linda; Pribesh, Shana
2011-01-01
This study investigated the extent to which higher-order thinking skills are promoted in social studies classes in high schools that are implementing smaller learning communities (SLCs). Data collection in this mixed-methods study included classroom observations and in-depth interviews. Findings indicated that higher-order thinking was rarely…
From "Hello" to Higher-Order Thinking: The Effect of Coaching and Feedback on Online Chats
Stein, David S.; Wanstreet, Constance E.; Slagle, Paula; Trinko, Lynn A.; Lutz, Michelle
2013-01-01
This exploratory study examined the effect of a coaching and feedback intervention in teaching presence and social presence on higher-order thinking in an online community of inquiry. Coaching occurred before each chat, and feedback was provided immediately afterwards. The findings suggest that over time, the frequency of higher-order thinking…
Comparing higher order models for the EORTC QLQ-C30
DEFF Research Database (Denmark)
Gundy, Chad M; Fayers, Peter M; Grønvold, Mogens
2012-01-01
To investigate the statistical fit of alternative higher order models for summarizing the health-related quality of life profile generated by the EORTC QLQ-C30 questionnaire.......To investigate the statistical fit of alternative higher order models for summarizing the health-related quality of life profile generated by the EORTC QLQ-C30 questionnaire....
Teaching Higher Order Thinking in the Introductory MIS Course: A Model-Directed Approach
Wang, Shouhong; Wang, Hai
2011-01-01
One vision of education evolution is to change the modes of thinking of students. Critical thinking, design thinking, and system thinking are higher order thinking paradigms that are specifically pertinent to business education. A model-directed approach to teaching and learning higher order thinking is proposed. An example of application of the…
Exact Solutions to Nonlinear Schroedinger Equation and Higher-Order Nonlinear Schroedinger Equation
International Nuclear Information System (INIS)
Ren Ji; Ruan Hangyu
2008-01-01
We study solutions of the nonlinear Schroedinger equation (NLSE) and higher-order nonlinear Schroedinger equation (HONLSE) with variable coefficients. By considering all the higher-order effect of HONLSE as a new dependent variable, the NLSE and HONLSE can be changed into one equation. Using the generalized Lie group reduction method (GLGRM), the abundant solutions of NLSE and HONLSE are obtained
Higher Order Thinking Skills among Secondary School Students in Science Learning
Saido, Gulistan Mohammed; Siraj, Saedah; Bin Nordin, Abu Bakar; Al Amedy, Omed Saadallah
2015-01-01
A central goal of science education is to help students to develop their higher order thinking skills to enable them to face the challenges of daily life. Enhancing students' higher order thinking skills is the main goal of the Kurdish Science Curriculum in the Iraqi-Kurdistan region. This study aimed at assessing 7th grade students' higher order…
Tanujaya, Benidiktus; Mumu, Jeinne; Margono, Gaguk
2017-01-01
Higher order thinking skills (HOTS) is one of important aspects in education. Students with high level of higher order thinking skills tend to be more successful. However, do this phenomenon also happen in the learning of Mathematics? To answer this question, this research aims to study the relationship between HOTS and students' academic…
Multi-domain, higher order level set scheme for 3D image segmentation on the GPU
DEFF Research Database (Denmark)
Sharma, Ojaswa; Zhang, Qin; Anton, François
2010-01-01
to evaluate level set surfaces that are $C^2$ continuous, but are slow due to high computational burden. In this paper, we provide a higher order GPU based solver for fast and efficient segmentation of large volumetric images. We also extend the higher order method to multi-domain segmentation. Our streaming...
Higher-order blackhole solutions in N=2 supergravity and Calabi-Yau string backgrounds
Behrndt, K.; Cardoso, G.L.; de Wit, B.Q.P.J.; Lüst, D.; Mohaupt, T.; Sabra, W.A.
1998-01-01
Based on special geometry, we consider corrections to N=2 extremal black-hole solutions and their entropies originating from higher-order derivative terms in N=2 supergravity. These corrections are described by a holomorphic function, and the higher-order black-hole solutions can be expressed in
Zhai, Yi; Wang, Yan; Wang, Zhaoqi; Liu, Yongji; Zhang, Lin; He, Yuanqing; Chang, Shengjiang
2014-01-01
An achromatic element eliminating only longitudinal chromatic aberration (LCA) while maintaining transverse chromatic aberration (TCA) is established for the eye model, which involves the angle formed by the visual and optical axis. To investigate the impacts of higher-order aberrations on vision, the actual data of higher-order aberrations of human eyes with three typical levels are introduced into the eye model along visual axis. Moreover, three kinds of individual eye models are established to investigate the impacts of higher-order aberrations, chromatic aberration (LCA+TCA), LCA and TCA on vision under the photopic condition, respectively. Results show that for most human eyes, the impact of chromatic aberration on vision is much stronger than that of higher-order aberrations, and the impact of LCA in chromatic aberration dominates. The impact of TCA is approximately equal to that of normal level higher-order aberrations and it can be ignored when LCA exists.
The Higher Order Structure of Environmental Attitudes: A Cross-Cultural Examination
Directory of Open Access Journals (Sweden)
Taciano L. Milfont
2010-01-01
Full Text Available Past research has suggested that Preservation and Utilization are the two higher order dimensions forming the hierarchical structure of environmental attitudes. This means that these two higher order dimensions could group all kinds of perceptions or beliefs regarding the natural environment people have. A crosscultural study was conducted in Brazil, New Zealand, and South Africa to test this hierarchical structure of environmental attitudes. Results from single- and multi-group confirmatory factor analyses demonstrated that environmental attitudes are a multidimensional construct, and that their first-order factors associate to each other to form a vertical structure. However, the question whether the vertical structure comprise a single higher order factor or two higher order factors still remains unanswered. These results are discussed and directions for future research trying to demonstrate that Preservation and Utilization, taken as distinct second-order environmental attitudes factors, are more empirically meaningful than a single and generalised environmental attitudes higher order factor are presented.
Place of birth,age of immigration,and disability in Hispanics with multiple sclerosis.
Amezcua, Lilyana; Conti, David V; Liu, Lihua; Ledezma, Karina; Langer-Goulda, Annette M
2015-01-01
Hispanics in the US are a diverse community where their knowledge and risk for developing disability in multiple sclerosis (MS) may relate to their level of acculturation. To compare the risk of disability in Hispanics with MS in the US by place of birth and age of immigration. We conducted a cross-sectional study of 304 Hispanics with MS residing in Southern California. Place of birth and age of immigration were used as proxies to acculturation. Individuals were classified as US-born, early and late-immigrant (immigration to the US, respectively). Risk of disability (expanded disability status scale ≥6) was adjusted for age at symptom onset, sex, socioeconomic status, and disease duration, using logistic regression. Late-immigrants were older at symptom onset (34.2±11.9 vs. 31.9±12.9 vs. 28.5±9.7 years, pimmigrant and US-born respectively. There was no difference between groups by female sex, type of MS, ethnicity, chronic medical conditions, and disease duration while differences were noted by socioeconomic status. Being late-immigrant was independently associated with increased disability (adjusted OR 2.3 95% CIs 1.07–4.82; p=0.03) compared to US-born. Later immigration to the US in Hispanics with MS is associated with greater disability. These findings may reflect differences in social, environmental and cultural factors that may act as barriers for accessibility and utilization of health services. An in-depth assessment of the perceptions and attitudes about MS are warranted in this population.
Liu, Chunlei; Murphy, Nicole E.; Li, Wei
2012-01-01
Diffusion MRI has become an invaluable tool for studying white matter microstructure and brain connectivity. The emergence of quantitative susceptibility mapping and susceptibility tensor imaging (STI) has provided another unique tool for assessing the structure of white matter. In the highly ordered white matter structure, diffusion MRI measures hindered water mobility induced by various tissue and cell membranes, while susceptibility sensitizes to the molecular composition and axonal arrangement. Integrating these two methods may produce new insights into the complex physiology of white matter. In this study, we investigated the relationship between diffusion and magnetic susceptibility in the white matter. Experiments were conducted on phantoms and human brains in vivo. Diffusion properties were quantified with the diffusion tensor model and also with the higher order tensor model based on the cumulant expansion. Frequency shift and susceptibility tensor were measured with quantitative susceptibility mapping and susceptibility tensor imaging. These diffusion and susceptibility quantities were compared and correlated in regions of single fiber bundles and regions of multiple fiber orientations. Relationships were established with similarities and differences identified. It is believed that diffusion MRI and susceptibility MRI provide complementary information of the microstructure of white matter. Together, they allow a more complete assessment of healthy and diseased brains. PMID:23507987
Higher-order-mode absorbers for energy recovery linac cryomodules at Brookhaven National Laboratory
Directory of Open Access Journals (Sweden)
H. Hahn
2010-12-01
Full Text Available Several future accelerator projects at Brookhaven for the Relativistic Heavy Ion Collider (RHIC are based on energy recovery linacs (ERLs with high-charge high-current electron beams. Their stable operation mandates effective higher-order-mode (HOM damping. The development of HOM dampers for these projects is pursued actively at this laboratory. Strong HOM damping was experimentally demonstrated both at room and at superconducting (SC temperatures in a prototype research and development (R&D five-cell niobium superconducting rf (SRF cavity with ferrite dampers. Two room-temperature mock-up five-cell copper cavities were used to study various damper configurations with emphasis on capacitive antenna dampers. An innovative type of ferrite damper over a ceramic break for an R&D SRF electron gun also was developed. For future SRF linacs longer cryomodules comprised of multiple superconducting cavities with reasonably short intercavity transitions are planned. In such a configuration, the dampers, located closer to the cavities, will be at cryogenic temperatures; this will impose additional constraints and complications. This paper presents the results of simulations and measurements of several damper configurations.
First-order and higher order sequence learning in specific language impairment.
Clark, Gillian M; Lum, Jarrad A G
2017-02-01
A core claim of the procedural deficit hypothesis of specific language impairment (SLI) is that the disorder is associated with poor implicit sequence learning. This study investigated whether implicit sequence learning problems in SLI are present for first-order conditional (FOC) and higher order conditional (HOC) sequences. Twenty-five children with SLI and 27 age-matched, nonlanguage-impaired children completed 2 serial reaction time tasks. On 1 version, the sequence to be implicitly learnt comprised a FOC sequence and on the other a HOC sequence. Results showed that the SLI group learned the HOC sequence (η p ² = .285, p = .005) but not the FOC sequence (η p ² = .099, p = .118). The control group learned both sequences (FOC η p ² = .497, HOC η p 2= .465, ps < .001). The SLI group's difficulty learning the FOC sequence is consistent with the procedural deficit hypothesis. However, the study provides new evidence that multiple mechanisms may underpin the learning of FOC and HOC sequences. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Higher-order-mode absorbers for energy recovery linac cryomodules at Brookhaven National Laboratory
International Nuclear Information System (INIS)
Hahn, H.; Ben-Zvi, I.; Calaga, R.; Hammons, L.; Johnson, E.C.; Kewisch, J.; Litvinenko, V.N.; Xu, W.
2010-01-01
Several future accelerator projects at Brookhaven for the Relativistic Heavy Ion Collider (RHIC) are based on energy recovery linacs (ERLs) with high-charge high-current electron beams. Their stable operation mandates effective higher-order-mode (HOM) damping. The development of HOM dampers for these projects is pursued actively at this laboratory. Strong HOM damping was experimentally demonstrated both at room and at superconducting (SC) temperatures in a prototype research and development (R and D) five-cell niobium superconducting rf (SRF) cavity with ferrite dampers. Two room-temperature mock-up five-cell copper cavities were used to study various damper configurations with emphasis on capacitive antenna dampers. An innovative type of ferrite damper over a ceramic break for an R and D SRF electron gun also was developed. For future SRF linacs longer cryomodules comprised of multiple superconducting cavities with reasonably short intercavity transitions are planned. In such a configuration, the dampers, located closer to the cavities, will be at cryogenic temperatures; this will impose additional constraints and complications. This paper presents the results of simulations and measurements of several damper configurations.
Higher-order-mode absorbers for energy recovery linac cryomodules at Brookhaven National Laboratory
Hahn, H.; Ben-Zvi, I.; Calaga, R.; Hammons, L.; Johnson, E. C.; Kewisch, J.; Litvinenko, V. N.; Xu, Wencan
2010-12-01
Several future accelerator projects at Brookhaven for the Relativistic Heavy Ion Collider (RHIC) are based on energy recovery linacs (ERLs) with high-charge high-current electron beams. Their stable operation mandates effective higher-order-mode (HOM) damping. The development of HOM dampers for these projects is pursued actively at this laboratory. Strong HOM damping was experimentally demonstrated both at room and at superconducting (SC) temperatures in a prototype research and development (R&D) five-cell niobium superconducting rf (SRF) cavity with ferrite dampers. Two room-temperature mock-up five-cell copper cavities were used to study various damper configurations with emphasis on capacitive antenna dampers. An innovative type of ferrite damper over a ceramic break for an R&D SRF electron gun also was developed. For future SRF linacs longer cryomodules comprised of multiple superconducting cavities with reasonably short intercavity transitions are planned. In such a configuration, the dampers, located closer to the cavities, will be at cryogenic temperatures; this will impose additional constraints and complications. This paper presents the results of simulations and measurements of several damper configurations.
Lim, A. C.; Hegeman, M. A.; In 't Veld, M. A. Huis; Opmeer, B. C.; Bruinse, H. W.; Mol, B. W. J.
Objectives To review the literature on cervical length as a predictor of preterm birth in asymptomatic women with a multiple pregnancy. Methods We searched MEDLINE, Embase and reference lists of included articles to identify all studies that reported on the accuracy of cervical length for predicting
Recirculating beam-breakup thresholds for polarized higher-order modes with optical coupling
Directory of Open Access Journals (Sweden)
Georg H. Hoffstaetter
2007-04-01
Full Text Available Here we will derive the general theory of the beam-breakup (BBU instability in recirculating linear accelerators with coupled beam optics and with polarized higher-order dipole modes. The bunches do not have to be at the same radio-frequency phase during each recirculation turn. This is important for the description of energy recovery linacs (ERLs where beam currents become very large and coupled optics are used on purpose to increase the threshold current. This theory can be used for the analysis of phase errors of recirculated bunches, and of errors in the optical coupling arrangement. It is shown how the threshold current for a given linac can be computed and a remarkable agreement with tracking data is demonstrated. General formulas are then analyzed for several analytically solvable problems: (a Why can different higher order modes (HOM in one cavity couple and why can they then not be considered individually, even when their frequencies are separated by much more than the resonance widths of the HOMs? For the Cornell ERL as an example, it is noted that optimum advantage is taken of coupled optics when the cavities are designed with an x-y HOM frequency splitting of above 50 MHz. The simulated threshold current is then far above the design current of this accelerator. To justify that the simulation can represent an actual accelerator, we simulate cavities with 1 to 8 modes and show that using a limited number of modes is reasonable. (b How does the x-y coupling in the particle optics determine when modes can be considered separately? (c How much of an increase in threshold current can be obtained by coupled optics and why does the threshold current for polarized modes diminish roughly with the square root of the HOMs’ quality factors. Because of this square root scaling, polarized modes with coupled optics increase the threshold current more effectively for cavities that have rather large HOM quality factors, e.g. those without very
Consensus Algorithms for Networks of Systems with Second- and Higher-Order Dynamics
Fruhnert, Michael
This thesis considers homogeneous networks of linear systems. We consider linear feedback controllers and require that the directed graph associated with the network contains a spanning tree and systems are stabilizable. We show that, in continuous-time, consensus with a guaranteed rate of convergence can always be achieved using linear state feedback. For networks of continuous-time second-order systems, we provide a new and simple derivation of the conditions for a second-order polynomials with complex coefficients to be Hurwitz. We apply this result to obtain necessary and sufficient conditions to achieve consensus with networks whose graph Laplacian matrix may have complex eigenvalues. Based on the conditions found, methods to compute feedback gains are proposed. We show that gains can be chosen such that consensus is achieved robustly over a variety of communication structures and system dynamics. We also consider the use of static output feedback. For networks of discrete-time second-order systems, we provide a new and simple derivation of the conditions for a second-order polynomials with complex coefficients to be Schur. We apply this result to obtain necessary and sufficient conditions to achieve consensus with networks whose graph Laplacian matrix may have complex eigenvalues. We show that consensus can always be achieved for marginally stable systems and discretized systems. Simple conditions for consensus achieving controllers are obtained when the Laplacian eigenvalues are all real. For networks of continuous-time time-variant higher-order systems, we show that uniform consensus can always be achieved if systems are quadratically stabilizable. In this case, we provide a simple condition to obtain a linear feedback control. For networks of discrete-time higher-order systems, we show that constant gains can be chosen such that consensus is achieved for a variety of network topologies. First, we develop simple results for networks of time
Verifying object-oriented programs with higher-order separation logic in Coq
DEFF Research Database (Denmark)
Bengtson, Jesper; Jensen, Jonas Braband; Sieczkowski, Filip
2011-01-01
We present a shallow Coq embedding of a higher-order separation logic with nested triples for an object-oriented programming language. Moreover, we develop novel specification and proof patterns for reasoning in higher-order separation logic with nested triples about programs that use interfaces...... and interface inheritance. In particular, we show how to use the higher-order features of the Coq formalisation to specify and reason modularly about programs that (1) depend on some unknown code satisfying a specification or that (2) return objects conforming to a certain specification. All of our results have...
Lagrangian-Hamiltonian unified formalism for autonomous higher order dynamical systems
International Nuclear Information System (INIS)
Prieto-Martinez, Pedro Daniel; Roman-Roy, Narciso
2011-01-01
The Lagrangian-Hamiltonian unified formalism of Skinner and Rusk was originally stated for autonomous dynamical systems in classical mechanics. It has been generalized for non-autonomous first-order mechanical systems, as well as for first-order and higher order field theories. However, a complete generalization to higher order mechanical systems is yet to be described. In this work, after reviewing the natural geometrical setting and the Lagrangian and Hamiltonian formalisms for higher order autonomous mechanical systems, we develop a complete generalization of the Lagrangian-Hamiltonian unified formalism for these kinds of systems, and we use it to analyze some physical models from this new point of view. (paper)
Higher order capacity statistics of multi-hop transmission systems over Rayleigh fading channels
Yilmaz, Ferkan
2012-03-01
In this paper, we present an exact analytical expression to evaluate the higher order statistics of the channel capacity for amplify and forward (AF) multihop transmission systems operating over Rayleigh fading channels. Furthermore, we present simple and efficient closed-form expression to the higher order moments of the channel capacity of dual hop transmission system with Rayleigh fading channels. In order to analyze the behavior of the higher order capacity statistics and investigate the usefulness of the mathematical analysis, some selected numerical and simulation results are presented. Our results are found to be in perfect agreement. © 2012 IEEE.
Modular specification and verification for higher-order languages with state
DEFF Research Database (Denmark)
Svendsen, Kasper
The overall topic of this thesis is modular reasoning for higher-order languages with state. The thesis consists of four mostly independent chapters that each deal with a different aspect of reasoning about higher-order languages with state. The unifying theme throughout all four chapters is higher....... The third chapter of the thesis is a case study of the C# joins library. What makes this library interesting as a case study is that it combines a lot of advanced features (higher-order code with effects, concurrency, recursion through the store, shared mutable state, and fine-grained synchronization...
Analysis of Scattering by Inhomogeneous Dielectric Objects Using Higher-Order Hierarchical MoM
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter
2003-01-01
An efficient technique for the analysis of electromagnetic scattering by arbitrary shaped inhomogeneous dielectric objects is presented. The technique is based on a higher-order method of moments (MoM) solution of the volume integral equation. This higher-order MoM solution comprises recently...... that the condition number of the resulting MoM matrix is reduced by several orders of magnitude in comparison to existing higher-order hierarchical basis functions and, consequently, an iterative solver can be applied even for high expansion orders. Numerical results demonstrate excellent agreement...
Generating higher-order Lie algebras by expanding Maurer-Cartan forms
International Nuclear Information System (INIS)
Caroca, R.; Merino, N.; Salgado, P.; Perez, A.
2009-01-01
By means of a generalization of the Maurer-Cartan expansion method, we construct a procedure to obtain expanded higher-order Lie algebras. The expanded higher-order Maurer-Cartan equations for the case G=V 0 +V 1 are found. A dual formulation for the S-expansion multialgebra procedure is also considered. The expanded higher-order Maurer-Cartan equations are recovered from S-expansion formalism by choosing a special semigroup. This dual method could be useful in finding a generalization to the case of a generalized free differential algebra, which may be relevant for physical applications in, e.g., higher-spin gauge theories.
Modeling 3D PCMI using the Extended Finite Element Method with higher order elements
Energy Technology Data Exchange (ETDEWEB)
Jiang, W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Spencer, Benjamin W. [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2017-03-31
This report documents the recent development to enable XFEM to work with higher order elements. It also demonstrates the application of higher order (quadratic) elements to both 2D and 3D models of PCMI problems, where discrete fractures in the fuel are represented using XFEM. The modeling results demonstrate the ability of the higher order XFEM to accurately capture the effects of a crack on the response in the vicinity of the intersecting surfaces of cracked fuel and cladding, as well as represent smooth responses in the regions away from the crack.
Higher-Order Blind Signal Feature Separation: An Enabling Technology for Battlefield Awareness
National Research Council Canada - National Science Library
Su, Wei; Kosinski, John A
2006-01-01
Higher-order transform blind signal feature classification is discussed for separating bar-shaped, circular, squared, circular-squared, and offset-diamonded constellation patterns of digital linear signals...
Higher-Order Wavefront Aberrations for Populations of Young Emmetropes and Myopes
Directory of Open Access Journals (Sweden)
Jinhua Bao
2009-01-01
Conclusions: Human eyes have systematical higher order aberrations in population, and factors that cause bilateral symmetry of wavefront aberrations between the right and left eyes made important contribution to the systematical aberrations.
Domin, Daniel S.
1999-01-01
The science laboratory instructional environment is ideal for fostering the development of problem-solving, manipulative, and higher-order thinking skills: the skills needed by today's learner to compete in an ever increasing technology-based society. This paper reports the results of a content analysis of ten general chemistry laboratory manuals. Three experiments from each manual were examined for evidence of higher-order cognitive activities. Analysis was based upon the six major cognitive categories of Bloom's Taxonomy of Educational Objectives: knowledge, comprehension, application, analysis, synthesis, and evaluation. The results of this study show that the overwhelming majority of general chemistry laboratory manuals provide tasks that require the use of only the lower-order cognitive skills: knowledge, comprehension, and application. Two of the laboratory manuals were disparate in having activities that utilized higher-order cognition. I describe the instructional strategies used within these manuals to foster higher-order cognitive development.
The Need to Deliver Higher-Order Skills in the Context of Marketing in SMEs
Copley, Paul
2013-01-01
It is argued that the delivery of learning and the development of skills and competences are central to SME success; and there appears to be a requirement for higher-order education and training that can deliver a
Covariant quantization of infinite spin particle models, and higher order gauge theories
International Nuclear Information System (INIS)
Edgren, Ludde; Marnelius, Robert
2006-01-01
Further properties of a recently proposed higher order infinite spin particle model are derived. Infinitely many classically equivalent but different Hamiltonian formulations are shown to exist. This leads to a condition of uniqueness in the quantization process. A consistent covariant quantization is shown to exist. Also a recently proposed supersymmetric version for half-odd integer spins is quantized. A general algorithm to derive gauge invariances of higher order Lagrangians is given and applied to the infinite spin particle model, and to a new higher order model for a spinning particle which is proposed here, as well as to a previously given higher order rigid particle model. The latter two models are also covariantly quantized
Higher-order asymptotic homogenization of periodic materials with low scale separation
Ameen, M.M.; Peerlings, R.H.J.; Geers, M.G.D
2016-01-01
In this work, we investigate the limits of classical homogenization theories pertaining to homogenization of periodic linear elastic composite materials at low scale separations and demonstrate the effectiveness of higher-order periodic homogenization in alleviating this limitation. Classical
Higher Order Thinking in the Australian Army Suite of Logistic Officer Courses
National Research Council Canada - National Science Library
Bradford, Scott R
2006-01-01
.... The current Suite of Logistic Officer Courses (SOLOC) has been recently criticized for failing to meet this requirement, with the general perception that there is a distinct lack of higher-order thinking competencies within this continuum...
Jaber, Nizar; Ramini, Abdallah; Carreno, Armando Arpys Arevalo; Younis, Mohammad I.
2016-01-01
© 2016 IOP Publishing Ltd. In this study, we demonstrate analytically and experimentally the excitations of the higher order modes of vibrations in electrostatically actuated clamped-clamped microbeam resonators. The concept is based on using
A stable higher order space time Galerkin marching-on-in-time scheme
Pray, Andrew J.; Shanker, Balasubramaniam; Bagci, Hakan
2013-01-01
We present a method for the stable solution of time-domain integral equations. The method uses a technique developed in [1] to accurately evaluate matrix elements. As opposed to existing stabilization schemes, the method presented uses higher order
Connection between weighted LPC and higher-order statistics for AR model estimation
Kamp, Y.; Ma, C.
1993-01-01
This paper establishes the relationship between a weighted linear prediction method used for robust analysis of voiced speech and the autoregressive modelling based on higher-order statistics, known as cumulants
Deformation from symmetry for Schrodinger equations of higher order on unbounded domains
Directory of Open Access Journals (Sweden)
Addolorata Salvatore
2003-06-01
Full Text Available By means of a perturbation method recently introduced by Bolle, we discuss the existence of infinitely many solutions for a class of perturbed symmetric higher order Schrodinger equations with non-homogeneous boundary data on unbounded domains.
Exact solutions for the higher-order nonlinear Schoerdinger equation in nonlinear optical fibres
International Nuclear Information System (INIS)
Liu Chunping
2005-01-01
First, by using the generally projective Riccati equation method, many kinds of exact solutions for the higher-order nonlinear Schoerdinger equation in nonlinear optical fibres are obtained in a unified way. Then, some relations among these solutions are revealed
Visualization and processing of higher order descriptors for multi-valued data
Schultz, Thomas
2015-01-01
Modern imaging techniques and computational simulations yield complex multi-valued data that require higher-order mathematical descriptors. This book addresses topics of importance when dealing with such data, including frameworks for image processing, visualization, and statistical analysis of higher-order descriptors. It also provides examples of the successful use of higher-order descriptors in specific applications and a glimpse of the next generation of diffusion MRI. To do so, it combines contributions on new developments, current challenges in this area, and state-of-the-art surveys. Compared to the increasing importance of higher-order descriptors in a range of applications, tools for analysis and processing are still relatively hard to come by. Even though application areas such as medical imaging, fluid dynamics, and structural mechanics are very different in nature they face many shared challenges. This book provides an interdisciplinary perspective on this topic with contributions from key rese...
The geometry of higher-order Lagrange spaces applications to mechanics and physics
Miron, Radu
1997-01-01
This monograph is devoted to the problem of the geometrizing of Lagrangians which depend on higher-order accelerations It presents a construction of the geometry of the total space of the bundle of the accelerations of order k>=1 A geometrical study of the notion of the higher-order Lagrange space is conducted, and the old problem of prolongation of Riemannian spaces to k-osculator manifolds is solved Also, the geometrical ground for variational calculus on the integral of actions involving higher-order Lagrangians is dealt with Applications to higher-order analytical mechanics and theoretical physics are included as well Audience This volume will be of interest to scientists whose work involves differential geometry, mechanics of particles and systems, calculus of variation and optimal control, optimization, optics, electromagnetic theory, and biology
Higher order capacity statistics of multi-hop transmission systems over Rayleigh fading channels
Yilmaz, Ferkan; Tabassum, Hina; Alouini, Mohamed-Slim
2012-01-01
In this paper, we present an exact analytical expression to evaluate the higher order statistics of the channel capacity for amplify and forward (AF) multihop transmission systems operating over Rayleigh fading channels. Furthermore, we present
Ampt, Amanda J; Ford, Jane B
2015-09-30
Population data are often used to monitor severe perineal trauma trends and investigate risk factors. Within New South Wales (NSW), two different datasets can be used, the Perinatal Data Collection ('birth' data) or a linked dataset combining birth data with the Admitted Patient Data Collection ('hospital' data). Severe perineal trauma can be ascertained by birth data alone, or by hospital International Classification of Diseases Australian Modification (ICD-10-AM) diagnosis and procedure coding in the linked dataset. The aim of this study was to compare rates and risk factors for severe perineal trauma using birth data alone versus using linked data. The study population consisted of all vaginal births in NSW between 2001 and 2011. Perineal injury coding in birth data was revised in 2006, so data were analysed separately for 2001-06 and 2006-11. Rates of severe perineal injury over time were compared in birth data alone versus linked data. Kappa and agreement statistics were calculated. Risk factor distributions (maternal age, primiparity, instrumental birth, birthweight ≥4 kg, Asian country of birth and episiotomy) were compared between women with severe perineal trauma identified by birth data alone, and those identified by linked data. Multivariable logistic regression was used to calculate the adjusted odds ratios (aORs) of severe perineal trauma. Among 697 202 women with vaginal births, 2.1% were identified with severe perineal trauma by birth data alone, and 2.6% by linked data. The rate discrepancy was higher among earlier data (1.7% for birth data, 2.4% for linked data). Kappa for earlier data was 0.78 (95% CI 0.78, 0.79), and 0.89 (95% CI 0.89, 0.89) for more recent data. With the exception of episiotomy, differences in risk factor distributions were small, with similar aORs. The aOR of severe perineal trauma for episiotomy was higher using linked data (1.33, 95% CI 1.27, 1.40) compared with birth data (1.02, 95% CI 0.97, 1.08). Although discrepancies
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav
2007-01-01
The problem of electromagnetic scattering by composite metallic and dielectric objects is solved using the coupled volume-surface integral equation (VSIE). The method of moments (MoM) based on higher-order hierarchical Legendre basis functions and higher-order curvilinear geometrical elements...... with the analytical Mie series solution. Scattering by more complex metal-dielectric objects are also considered to compare the presented technique with other numerical methods....
Ultra-compact Higher-Order-Mode Pass Filter in a Silicon Waveguide
DEFF Research Database (Denmark)
Guan, Xiaowei; Frandsen, Lars Hagedorn; Ding, Yunhong
2015-01-01
An 3.7 μm long higher-order-mode pass filter with an extinction ratio larger than 20 dB is demonstrated in a 1D corrugated silicon multimode waveguide......An 3.7 μm long higher-order-mode pass filter with an extinction ratio larger than 20 dB is demonstrated in a 1D corrugated silicon multimode waveguide...
Higher order mode of a microstripline fed cylindrical dielectric resonator antenna
Energy Technology Data Exchange (ETDEWEB)
Kumar, A. V. Praveen, E-mail: praveen.kumar@pilani.bits-pilani.ac.in [Department of Electrical and Electronics Engineering, BITS Pilani, Pilani, Rajasthan-333 031 (India)
2016-03-09
A microstrip transmission line can be used to excite the broadside radiating mode of a cylindrical dielectric resonator antenna (CDRA). The same is found to excite considerably well a higher order mode (HOM) as well. However unlike the broadside mode, the higher order mode gives distorted radiation pattern which makes this mode less useful for practical applications. The cause of distortion in the HOM radiation and the dependence of HOM coupling on the microstrip feed line are explored using HFSS simulations.
Defining Higher-Order Turbulent Moment Closures with an Artificial Neural Network and Random Forest
McGibbon, J.; Bretherton, C. S.
2017-12-01
Unresolved turbulent advection and clouds must be parameterized in atmospheric models. Modern higher-order closure schemes depend on analytic moment closure assumptions that diagnose higher-order moments in terms of lower-order ones. These are then tested against Large-Eddy Simulation (LES) higher-order moment relations. However, these relations may not be neatly analytic in nature. Rather than rely on an analytic higher-order moment closure, can we use machine learning on LES data itself to define a higher-order moment closure?We assess the ability of a deep artificial neural network (NN) and random forest (RF) to perform this task using a set of observationally-based LES runs from the MAGIC field campaign. By training on a subset of 12 simulations and testing on remaining simulations, we avoid over-fitting the training data.Performance of the NN and RF will be assessed and compared to the Analytic Double Gaussian 1 (ADG1) closure assumed by Cloudy Layers Unified By Binormals (CLUBB), a higher-order turbulence closure currently used in the Community Atmosphere Model (CAM). We will show that the RF outperforms the NN and the ADG1 closure for the MAGIC cases within this diagnostic framework. Progress and challenges in using a diagnostic machine learning closure within a prognostic cloud and turbulence parameterization will also be discussed.
Directory of Open Access Journals (Sweden)
Yoon Woojin
2011-06-01
Full Text Available Abstract Background Studies comparing perinatal outcomes in multiples conceived following the use of artificial reproductive technologies (ART vs. spontaneous conception (SC have reported conflicting results in terms of mortality and morbidity. Therefore, the objective of our study was to compare composite outcome of mortality and severe neonatal morbidities amongst preterm multiple births ≤ 32 weeks gestation infant born following ART vs. SC. Methods We conducted a single center cohort study at Mount Sinai Hospital, Toronto, Ontario, Canada. Data on all preterm multiple births (≤ 32 weeks GA discharged between July 2005 and June 2008 were retrospectively collected from a prospective database at our centre. Details regarding mode of conception were collected retrospectively from maternal health records. Preterm multiple births were categorized into those born following ART vs. SC. Composite outcome was defined as combination of death or any of the three neonatal morbidities (grade 3/4 intraventricular hemorrhage or periventricular leukomalacia; retinopathy of prematurity > stage 2 or chronic lung disease. Univariate and multivariate regression analysis were preformed after adjustment of confounders (maternal age, parity, triplets, gestational age, sex, and small for gestational age. Results One hundred and thirty seven neonates were born following use of ART and 233 following SC. The unadjusted composite outcome rate was significantly higher in preterm multiples born following ART vs. SC [43.1% vs. 26.6%, p = 0.001; OR 1.98 (95% CI 1.13, 3.45]; however, when adjusted for confounders the difference between groups was not statistically significant [OR 1.39, 95% CI 0.67, 2.89]. Conclusion In our population of preterm multiple births, the mode of conception had no detectable effect on the adjusted composite neonatal outcome of mortality and/or three neonatal morbidities.
Energy Technology Data Exchange (ETDEWEB)
Sun, Hongwei; Pistorius, Stephen [Department of Physics and Astronomy, University of Manitoba, CancerCare, Manitoba (Canada)
2016-08-15
PET images are affected by the presence of scattered photons. Incorrect scatter-correction may cause artifacts, particularly in 3D PET systems. Current scatter reconstruction methods do not distinguish between single and higher order scattered photons. A dual-scattered reconstruction method (GDS-MLEM) that is independent of the number of Compton scattering interactions and less sensitive to the need for high energy resolution detectors, is proposed. To avoid overcorrecting for scattered coincidences, the attenuation coefficient was calculated by integrating the differential Klein-Nishina cross-section over a restricted energy range, accounting only for scattered photons that were not detected. The optimum image can be selected by choosing an energy threshold which is the upper energy limit for the calculation of the cross-section and the lower limit for scattered photons in the reconstruction. Data was simulated using the GATE platform. 500,000 multiple scattered photon coincidences with perfect energy resolution were reconstructed using various methods. The GDS-MLEM algorithm had the highest confidence (98%) in locating the annihilation position and was capable of reconstructing the two largest hot regions. 100,000 photon coincidences, with a scatter fraction of 40%, were used to test the energy resolution dependence of different algorithms. With a 350–650 keV energy window and the restricted attenuation correction model, the GDS-MLEM algorithm was able to improve contrast recovery and reduce the noise by 7.56%–13.24% and 12.4%–24.03%, respectively. This approach is less sensitive to the energy resolution and shows promise if detector energy resolutions of 12% can be achieved.
Higher order aberrations in amblyopic children and their role in refractory amblyopia
Directory of Open Access Journals (Sweden)
Arnaldo Dias-Santos
2014-12-01
Full Text Available Objective: Some studies have hypothesized that an unfavourable higher order aberrometric profile could act as an amblyogenic mechanism and may be responsible for some amblyopic cases that are refractory to conventional treatment or cases of “idiopathic” amblyopia. This study compared the aberrometric profile in amblyopic children to that of children with normal visual development and compared the aberrometric profile in corrected amblyopic eyes and refractory amblyopic eyes with that of healthy eyes. Methods: Cross-sectional study with three groups of children – the CA group (22 eyes of 11 children with unilateral corrected amblyopia, the RA group (24 eyes of 13 children with unilateral refractory amblyopia and the C group (28 eyes of 14 children with normal visual development. Higher order aberrations were evaluated using an OPD-Scan III (NIDEK. Comparisons of the aberrometric profile were made between these groups as well as between the amblyopic and healthy eyes within the CA and RA groups. Results: Higher order aberrations with greater impact in visual quality were not significantly higher in the CA and RA groups when compared with the C group. Moreover, there were no statistically significant differences in the higher order aberrometric profile between the amblyopic and healthy eyes within the CA and RA groups. Conclusions: Contrary to lower order aberrations (e.g., myopia, hyperopia, primary astigmatism, higher order aberrations do not seem to be involved in the etiopathogenesis of amblyopia. Therefore, these are likely not the cause of most cases of refractory amblyopia.
Structural damage detection using higher-order finite elements and a scanning laser vibrometer
Jin, Si
In contrast to conventional non-destructive evaluation methods, dynamics-based damage detection methods are capable of rapid integrity evaluation of large structures and have received considerable attention from aerospace, mechanical, and civil engineering communities in recent years. However, the identifiable damage size using dynamics-based methods is determined by the number of sensors used, level of measurement noise, accuracy of structural models, and signal processing techniques. In this thesis we study dynamics of structures with damage and then derive and experimentally verify new model-independent structural damage detection methods that can locate small damage to structures. To find sensitive damage detection parameters we develop a higher-order beam element that enforces the continuity of displacements, slopes, bending moments, and shear forces at all nodes, and a higher-order rectangular plate element that enforces the continuity of displacements, slopes, and bending and twisting moments at all nodes. These two elements are used to study the dynamics of beams and plates. Results show that high-order spatial derivatives of high-frequency modes are important sensitive parameters that can locate small structural damage. Unfortunately the most powerful and popular structural modeling technique, the finite element method, is not accurate in predicting high-frequency responses. Hence, a model-independent method using dynamic responses obtained from high density measurements is concluded to be the best approach. To increase measurement density and reduce noise a Polytec PI PSV-200 scanning laser vibrometer is used to provide non-contact, dense, and accurate measurements of structural vibration velocities. To avoid the use of structural models and to extract sensitive detection parameters from experimental data, a brand-new structural damage detection method named BED (Boundary-Effect Detection) is developed for pinpointing damage locations using Operational
Asztalos, Elizabeth V; Murphy, Kellie E; Willan, Andrew R; Matthews, Stephen G; Ohlsson, Arne; Saigal, Saroj; Armson, B Anthony; Kelly, Edmond N; Delisle, Marie-France; Gafni, Amiram; Lee, Shoo K; Sananes, Renee; Rovet, Joanne; Guselle, Patricia; Amankwah, Kofi; Saleem, Mariam; Sanchez, Johanna
2013-12-01
A single course of antenatal corticosteroid therapy is recommended for pregnant women at risk of preterm birth between 24 and 33 weeks' gestational age. However, 50% of women remain pregnant 7 to 14 days later, leading to the question of whether additional courses should be given to women remaining at risk for preterm birth. The Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study (MACS) was an international randomized clinical trial that compared multiple courses of antenatal corticosteroids with a single course in women at risk of preterm birth. To determine the effects of single vs multiple courses of antenatal corticosteroid therapy on death or neurodevelopmental disability (neuromotor, neurosensory, or neurocognitive/neurobehavioral function) at 5 years of age in children whose mothers participated in MACS. Our secondary aims were to determine the effect on height, weight, head circumference, blood pressure, intelligence, and specific cognitive (visual, spatial, and language) skills. Cohort follow-up study of children seen between June 2006 and May 2012 at 55 centers. In total, 1724 women (2141 children) were eligible for the study, of whom 1728 children (80.7% of the 2141 eligible children) participated and 1719 children contributed to the primary outcome. Single and multiple courses of antenatal corticosteroid therapy. The primary outcome was death or survival with a neurodevelopmental disability in 1 of the following domains: neuromotor (nonambulatory cerebral palsy), neurosensory (blindness, deafness, or need for visual/hearing aids), or neurocognitive/neurobehavioral function (abnormal attention, memory, or behavior). There was no significant difference between the groups in the risk of death or neurodevelopmental disability: 217 of 871 children (24.9%) in the multiple-courses group vs 210 of 848 children (24.8%) in the single-course group (odds ratio, 1.02 [95% CI, 0.81 to 1.29]; P = .84). Multiple courses, compared with a single
MIMO processing based on higher-order Poincaré spheres
Fernandes, Gil M.; Muga, Nelson J.; Pinto, Armando N.
2017-08-01
A multi-input multi-output (MIMO) algorithm based on higher-order Poincaré spheres is demonstrated for space-division multiplexing (SDM) systems. The MIMO algorithm is modulation format agnostic, robust to frequency offset and does not require training sequences. In this approach, the space-multiplexed signal is decomposed in sets of two tributary signals, with each set represented in a higher-order Poincaré sphere. For any arbitrary complex modulation format, the samples of two tributaries can be represented in a given higher-order Poincaré sphere with a symmetry plane. The crosstalk along propagation changes the spatial orientation of this plane and, therefore, it can be compensated by computing and realigning the best fit plane. We show how the transmitted signal can be successfully recovered using this procedure for all possible combinations of tributaries. Moreover, we analyze the convergence speed for the MIMO technique considering several optical-to-noise ratios.
Recurrent activity in higher order, modality non-specific brain regions
DEFF Research Database (Denmark)
Lou, Hans Olav Christensen; Joensson, Morten; Biermann-Ruben, Katja
2011-01-01
It has been proposed that the workings of the brain are mainly intrinsically generated recurrent neuronal activity, with sensory inputs as modifiers of such activity in both sensory and higher order modality non-specific regions. This is supported by the demonstration of recurrent neuronal activity...... in the visual system as a response to visual stimulation. In contrast recurrent activity has never been demonstrated before in higher order modality non-specific regions. Using magneto-encephalography and Granger causality analysis, we tested in a paralimbic network the hypothesis that stimulation may enhance...... causal recurrent interaction between higher-order, modality non-specific regions. The network includes anterior cingulate/medial prefrontal and posterior cingulate/medial parietal cortices together with pulvinar thalami, a network known to be effective in autobiographic memory retrieval and self...
Higher order polynomial expansion nodal method for hexagonal core neutronics analysis
International Nuclear Information System (INIS)
Jin, Young Cho; Chang, Hyo Kim
1998-01-01
A higher-order polynomial expansion nodal(PEN) method is newly formulated as a means to improve the accuracy of the conventional PEN method solutions to multi-group diffusion equations in hexagonal core geometry. The new method is applied to solving various hexagonal core neutronics benchmark problems. The computational accuracy of the higher order PEN method is then compared with that of the conventional PEN method, the analytic function expansion nodal (AFEN) method, and the ANC-H method. It is demonstrated that the higher order PEN method improves the accuracy of the conventional PEN method and that it compares very well with the other nodal methods like the AFEN and ANC-H methods in accuracy
A Linear-Elasticity Solver for Higher-Order Space-Time Mesh Deformation
Diosady, Laslo T.; Murman, Scott M.
2018-01-01
A linear-elasticity approach is presented for the generation of meshes appropriate for a higher-order space-time discontinuous finite-element method. The equations of linear-elasticity are discretized using a higher-order, spatially-continuous, finite-element method. Given an initial finite-element mesh, and a specified boundary displacement, we solve for the mesh displacements to obtain a higher-order curvilinear mesh. Alternatively, for moving-domain problems we use the linear-elasticity approach to solve for a temporally discontinuous mesh velocity on each time-slab and recover a continuous mesh deformation by integrating the velocity. The applicability of this methodology is presented for several benchmark test cases.
Collocated electrodynamic FDTD schemes using overlapping Yee grids and higher-order Hodge duals
Deimert, C.; Potter, M. E.; Okoniewski, M.
2016-12-01
The collocated Lebedev grid has previously been proposed as an alternative to the Yee grid for electromagnetic finite-difference time-domain (FDTD) simulations. While it performs better in anisotropic media, it performs poorly in isotropic media because it is equivalent to four overlapping, uncoupled Yee grids. We propose to couple the four Yee grids and fix the Lebedev method using discrete exterior calculus (DEC) with higher-order Hodge duals. We find that higher-order Hodge duals do improve the performance of the Lebedev grid, but they also improve the Yee grid by a similar amount. The effectiveness of coupling overlapping Yee grids with a higher-order Hodge dual is thus questionable. However, the theoretical foundations developed to derive these methods may be of interest in other problems.
International Nuclear Information System (INIS)
Kawano, S.
2003-01-01
Magnetic materials consisting of rare earth ions form modulation structures such as a helical or sinusoidal structure caused by the oscillating magnetic interaction between rare earth ions due to RKKY magnetic interaction. These modulation structures, in some cases, develop further to higher order modulation structures by additional modulations caused by higher order crystalline electric field, magnetic interactions such as spin-lattice interaction, external magnetic field and pressure. The higher order modulation structures are observed in a spin-slip structure or a helifan structure in Ho, and a tilt helix structure in a TbEr alloy. Paramagnetic ions originated from frustration generate many magnetic phases under applied external magnetic field. KUR neutron diffraction groups have performed the development and adjustment of high-pressure instruments and external magnetic fields for neutron diffraction spectrometers. The studies of 'neutron diffraction under extreme conditions' by the seven groups are described in this report. (Y. Kazumata)
Development of a Higher Order Laminate Theory for Modeling Composites with Induced Strain Actuators
Chattopadhyay, Aditi; Seeley, Charles E.
1996-01-01
A refined higher order plate theory is developed to investigate the actuation mechanism of piezoelectric materials surface bonded or embedded in composite laminates. The current analysis uses a displacement field which accurately accounts for transverse shear stresses. Some higher order terms are identified by using the conditions that shear stresses vanish at all free surfaces. Therefore, all boundary conditions for displacements and stresses are satisfied in the present theory. The analysis is implemented using the finite element method which provides a convenient means to construct a numerical solution due to the discrete nature of the actuators. The higher order theory is computationally less expensive than a full three dimensional analysis. The theory is also shown to agree well with published experimental results. Numerical examples are presented for composite plates with thicknesses ranging from thin to very thick.
Application of Higher-Order Cumulant in Fault Diagnosis of Rolling Bearing
International Nuclear Information System (INIS)
Shen, Yongjun; Yang, Shaopu; Wang, Junfeng
2013-01-01
In this paper a new method of pattern recognition based on higher-order cumulant and envelope analysis is presented. The core of this new method is to construct analytical signals from the given signals and obtain the envelope signals firstly, then compute and compare the higher-order cumulants of the envelope signals. The higher-order cumulants could be used as a characteristic quantity to distinguish these given signals. As an example, this method is applied in fault diagnosis for 197726 rolling bearing of freight locomotive. The comparisons of the second-order, third-order and fourth-order cumulants of the envelope signals from different vibration signals of rolling bearing show this new method could discriminate the normal and two fault signals distinctly
Equivalence of two Fixed-Point Semantics for Definitional Higher-Order Logic Programs
Directory of Open Access Journals (Sweden)
Angelos Charalambidis
2015-09-01
Full Text Available Two distinct research approaches have been proposed for assigning a purely extensional semantics to higher-order logic programming. The former approach uses classical domain theoretic tools while the latter builds on a fixed-point construction defined on a syntactic instantiation of the source program. The relationships between these two approaches had not been investigated until now. In this paper we demonstrate that for a very broad class of programs, namely the class of definitional programs introduced by W. W. Wadge, the two approaches coincide (with respect to ground atoms that involve symbols of the program. On the other hand, we argue that if existential higher-order variables are allowed to appear in the bodies of program rules, the two approaches are in general different. The results of the paper contribute to a better understanding of the semantics of higher-order logic programming.
A finite deformation theory of higher-order gradient crystal plasticity
DEFF Research Database (Denmark)
Kuroda, Mitsutoshi; Tvergaard, Viggo
2008-01-01
crystal plasticity that is based on an assumption of the existence of higher-order stresses. Furthermore, a boundary-value problem for simple shear of a constrained thin strip is studied numerically, and some characteristic features of finite deformation are demonstrated through a comparison to a solution......For higher-order gradient crystal plasticity, a finite deformation formulation is presented. The theory does not deviate much from the conventional crystal plasticity theory. Only a back stress effect and additional differential equations for evolution of the geometrically necessary dislocation...
Higher-order geodesic deviation for charged particles and resonance induced by gravitational waves
Heydari-Fard, M.; Hasani, S. N.
We generalize the higher-order geodesic deviation for the structure-less test particles to the higher-order geodesic deviation equations of the charged particles [R. Kerner, J. W. van Holten and R. Colistete Jr., Class. Quantum Grav. 18 (2001) 4725]. By solving these equations for charged particles moving in a constant magnetic field in the spacetime of a gravitational wave, we show for both cases when the gravitational wave is parallel and perpendicular to the constant magnetic field, a magnetic resonance appears at wg = Ω. This feature might be useful to detect the gravitational wave with high frequencies.
Higher-order resonant electronic recombination as a manifestation of configuration interaction
International Nuclear Information System (INIS)
Beilmann, C; Amaro, P; Tashenov, S; Bekker, H; Harman, Z; Crespo López-Urrutia, J R
2013-01-01
Theoretical and experimental investigations of higher-order electron–ion recombination resonances including inter-shell excitations are presented for L-shell ions of Kr with the aim of examining details of atomic structure calculations. The particular importance of electron–electron interaction and configuration mixing effects for these recombination processes enables their use for detailed tests of electron correlation effects. A test of the required level of considered mixing configurations is presented and further experiments involving higher-order recombination channels are motivated. (paper)
Higher order BLG supersymmetry transformations from 10-dimensional super Yang Mills
Energy Technology Data Exchange (ETDEWEB)
Hall, John [Alumnus of Physics Department, Imperial College,South Kensington, London, SW7 2AZ (United Kingdom); Low, Andrew [Physics Department, Wimbledon High School,Mansel Road, London, SW19 4AB (United Kingdom)
2014-06-26
We study a Simple Route for constructing the higher order Bagger-Lambert-Gustavsson theory - both supersymmetry transformations and Lagrangian - starting from knowledge of only the 10-dimensional Super Yang Mills Fermion Supersymmetry transformation. We are able to uniquely determine the four-derivative order corrected supersymmetry transformations, to lowest non-trivial order in Fermions, for the most general three-algebra theory. For the special case of Euclidean three-algbera, we reproduce the result presented in arXiv:1207.1208, with significantly less labour. In addition, we apply our method to calculate the quadratic fermion terms in the higher order BLG fermion supersymmetry transformation.
Czech Academy of Sciences Publication Activity Database
Mukhigulashvili, Sulkhan
-, č. 35 (2015), s. 23-50 ISSN 1126-8042 Institutional support: RVO:67985840 Keywords : higher order functional differential equations * Dirichlet boundary value problem * strong singularity Subject RIV: BA - General Mathematics http://ijpam.uniud.it/online_issue/201535/03-Mukhigulashvili.pdf
Toward an Understanding of Higher-Order Thinking among Minority Students.
Armour-Thomas, Eleanor; And Others
1992-01-01
Used principal-factors extraction with varimax rotation analysis to clarify nature and function of higher-order thinking among minority high school students (n=107) from economically disadvantaged backgrounds. Results allowed for specification of mental processes associated with the construct and the extent to which students reported awareness and…
Saragih, Sahat; Napitupulu, E. Elvis; Fauzi, Amin
2017-01-01
This research aims to develop a student-centered learning model based on local culture and instrument of mathematical higher order thinking of junior high school students in the frame of the 2013-Curriculum in North Sumatra, Indonesia. The subjects of the research are seventh graders which are taken proportionally random consisted of three public…
In-Service Teacher Education: Asking Questions for Higher Order Thinking in Visual Literacy
Moodley, Visvaganthie
2013-01-01
The kinds of questions teachers ask may thwart or promote learner high-order thinking; teachers themselves must have expertise in questioning skills to promote higher order cognition among learners. Drawing on experiential knowledge of assessment, and as an English-teaching professional development programme (PDP) facilitator, I demonstrate that…
Tanujaya, Benidiktus
2016-01-01
The purpose of this research was to develop an instrument that can be used to measure higher-order thinking skills (HOTS) in mathematics instruction of high school students. This research was conducted using a standard procedure of instrument development, from the development of conceptual definitions, development of operational definitions,…
The Higher Order Factor Structure and Gender Invariance of the Pathological Narcissism Inventory
Wright, Aidan G. C.; Lukowitsky, Mark R.; Pincus, Aaron L.; Conroy, David E.
2010-01-01
The Pathological Narcissism Inventory (PNI) is a recently developed multidimensional inventory for the assessment of pathological narcissism. The authors describe and report the results of two studies that investigate the higher order factor structure and gender invariance of the PNI. The results of the first study indicate that the PNI has a…
The advantage of higher-order theory of mind in the game of limited bidding
De Weerd, H.; Verheij, B.; van Eijck, J.; Verbrugge, L. C.
2011-01-01
Higher-order theory of mind is the ability to recursively model mental states of other agents. It is known that adults in general can reason adequately at the second order (covering attributions like "Alice knows that Bob knows that she wrote a novel under pseudonym"), but there are cognitive limits
Massive, massless and ghost modes of gravitational waves from higher-order gravity
DEFF Research Database (Denmark)
Bogdanos, Charalampos; Capozziello, Salvatore; De Laurentis, Mariafelicia
We linearize the field equations for higher order theories that contain scalar invariants other than the Ricci scalar. We find that besides a massless spin-2 field (the standard graviton), the theory contains also spin-0 and spin-2 massive modes with the latter being, in general, ghost modes. Then...
Impedance Eduction in Large Ducts Containing Higher-Order Modes and Grazing Flow
Watson, Willie R.; Jones, Michael G.
2017-01-01
Impedance eduction test data are acquired in ducts with small and large cross-sectional areas at the NASA Langley Research Center. An improved data acquisition system in the large duct has resulted in increased control of the acoustic energy in source modes and more accurate resolution of higher-order duct modes compared to previous tests. Two impedance eduction methods that take advantage of the improved data acquisition to educe the liner impedance in grazing flow are presented. One method measures the axial propagation constant of a dominant mode in the liner test section (by implementing the Kumarsean and Tufts algorithm) and educes the impedance from an exact analytical expression. The second method solves numerically the convected Helmholtz equation and minimizes an objective function to obtain the liner impedance. The two methods are tested first on data synthesized from an exact mode solution and then on measured data. Results show that when the methods are applied to data acquired in the larger duct with a dominant higher-order mode, the same impedance spectra are educed as that obtained in the small duct where only the plane wave mode propagates. This result holds for each higher-order mode in the large duct provided that the higher-order mode is sufficiently attenuated by the liner.
Controlled generation of higher-order Poincaré sphere beams from a laser
CSIR Research Space (South Africa)
Naidoo, Darryl
2016-03-01
Full Text Available . 10: 327-332 Controlled generation of higher-order Poincaré sphere beams from a laser Naidoo D Roux FS Dudley A Litvin I Piccirillo B Marrucci L Forbes A ABSTRACT: The angular momentum of light can be described by positions on a...
On the origin of higher braces and higher-order derivations
Czech Academy of Sciences Publication Activity Database
Markl, Martin
2015-01-01
Roč. 10, č. 3 (2015), s. 637-667 ISSN 2193-8407 Institutional support: RVO:67985840 Keywords : Koszul braces * Börjeseon braces * higher-order derivation Subject RIV: BA - General Mathematics Impact factor: 0.600, year: 2015 http://link.springer.com/article/10.1007/s40062-014-0079-2
Superpositions of higher-order bessel beams and nondiffracting speckle fields
CSIR Research Space (South Africa)
Dudley, Angela L
2009-08-01
Full Text Available speckle fields. The paper reports on illuminating a ring slit aperture with light which has an azimuthal phase dependence, such that the field produced is a superposition of two higher-order Bessel beams. In the case that the phase dependence of the light...
EXISTENCE OF PERIODIC SOLUTION TO HIGHER ORDER DIFFERENTIAL EQUATIONS WITH DEVIATING ARGUMENT
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
In this paper,using the coincidence degree theory of Mawhin,we investigate the existence of periodic solutions to higher order differential equations with deviating argument. Some new results on the existence of periodic solutions to the equations are obtained. In addition,we give an example to illustrate the main results.
Dori, Yehudit J.; Tal, Revital T.; Tsaushu, Masha
2003-01-01
Teaching nonscience majors topics in biotechnology through case studies is the focus of this research. Our "Biotechnology, Environment, and Related Issues" module, developed within the "Science for All" framework, is aimed at elevating the level of students' scientific and technological literacy and their higher order thinking…
Compound waves in a higher order nonlinear model of thermoviscous fluids
DEFF Research Database (Denmark)
Rønne Rasmussen, Anders; Sørensen, Mads Peter; Gaididei, Yuri B.
2016-01-01
A generalized traveling wave ansatz is used to investigate compound shock waves in a higher order nonlinear model of a thermoviscous fluid. The fluid velocity potential is written as a traveling wave plus a linear function of space and time. The latter offers the possibility of predicting...
Oscillation of certain higher-order neutral partial functional differential equations.
Li, Wei Nian; Sheng, Weihong
2016-01-01
In this paper, we study the oscillation of certain higher-order neutral partial functional differential equations with the Robin boundary conditions. Some oscillation criteria are established. Two examples are given to illustrate the main results in the end of this paper.
McGill, Ryan J.; Canivez, Gary L.
2016-01-01
As recommended by Carroll, the present study examined the factor structure of the Wechsler Intelligence Scale for Children-Fourth Edition Spanish (WISC-IV Spanish) normative sample using higher order exploratory factor analytic techniques not included in the WISC-IV Spanish Technical Manual. Results indicated that the WISC-IV Spanish subtests were…
A review of higher order strain gradient theories of plasticity: Origins ...
Indian Academy of Sciences (India)
require higher order boundary conditions that enable us to model effects of disloca- ..... where ǫ0 is a reference strain, σ0 the yield stress and n the strain hardening exponent. The ...... Petch N J 1953 J. Iron Steel Inst. London 173: 25. Pantleon ...
Foundational (co)datatypes and (co)recursion for higher-order logic
Biendarra, Julian; Blanchette, Jasmin Christian; Bouzy, Aymeric; Desharnais, Martin; Fleury, Mathias; Hölzl, Johannes; Kunčar, Ondřej; Lochbihler, Andreas; Meier, Fabian; Panny, Lorenz; Popescu, Andrei; Sternagel, Christian; Thiemann, René; Traytel, Dmitriy; Dixon, C.; Finger, M.
2017-01-01
We describe a line of work that started in 2011 towards enriching Isabelle/HOL’s language with coinductive datatypes, which allow infinite values, and with a more expressive notion of inductive datatype than previously supported by any system based on higher-order logic. These (co)datatypes are
Higher-order QCD corrections to inclusive particle production in panti p collisions
International Nuclear Information System (INIS)
Borzumati, F.M.; Kniehl, B.A.; Kramer, G.
1992-10-01
Inclusive single-particle production cross sections have been calculated including higher-order QCD corrections. Transverse-momentum and rapidity distributions are presented and the scale dependence is studied. The results are compared with experimental data from the CERN Spanti pS Collider and the Fermilab Tevatron. (orig.)
On realization of nonlinear systems described by higher-order differential equations
van der Schaft, Arjan
1987-01-01
We consider systems of smooth nonlinear differential and algebraic equations in which some of the variables are distinguished as “external variables.” The realization problem is to replace the higher-order implicit differential equations by first-order explicit differential equations and the
Stabilization of solutions to higher-order nonlinear Schrodinger equation with localized damping
Directory of Open Access Journals (Sweden)
Eleni Bisognin
2007-01-01
Full Text Available We study the stabilization of solutions to higher-order nonlinear Schrodinger equations in a bounded interval under the effect of a localized damping mechanism. We use multiplier techniques to obtain exponential decay in time of the solutions of the linear and nonlinear equations.
Wang, Chao; Yang, Chuan-sheng
2017-09-01
In this paper, we present a simplified parsimonious higher-order multivariate Markov chain model with new convergence condition. (TPHOMMCM-NCC). Moreover, estimation method of the parameters in TPHOMMCM-NCC is give. Numerical experiments illustrate the effectiveness of TPHOMMCM-NCC.
Brady, Timothy F.; Tenenbaum, Joshua B.
2013-01-01
When remembering a real-world scene, people encode both detailed information about specific objects and higher order information like the overall gist of the scene. However, formal models of change detection, like those used to estimate visual working memory capacity, assume observers encode only a simple memory representation that includes no…
Higher order hierarchical discretization scheme for surface integral equations for layered media
DEFF Research Database (Denmark)
Jørgensen, Erik; Kim, Oleksiy S.; Meincke, Peter
2004-01-01
This paper presents an efficient technique for the analysis of electromagnetic scattering by arbitrarily shaped perfectly conducting objects in layered media. The technique is based on a higher order method of moments (MoM) solution of the electric field, magnetic field, or combined-field integra...
Shape invariant higher-order Bessel-like beams carrying orbital angular momentum
CSIR Research Space (South Africa)
Ismail, Y
2012-09-01
Full Text Available -1 Journal of Optics September 2012/ Vol. 14 Shape invariant higher-order Bessel-like beams carrying orbital angular momentum Y Ismail1,2, N Khilo3, V Belyi3 and A Forbes1,2 1 School of Physics, University of KwaZulu-Natal, Private Bag X54001...
Perturbative theory of higher-order collision-enhanced wave mixing
International Nuclear Information System (INIS)
Trebino, R.; Rahn, L.A.
1989-01-01
This paper reports on collision-enhanced resonances which represent an interesting class of nonlinear- optical processes. They occur because collisional dephasing can rephase quantum-mechanical amplitudes that ordinarily cancel out exactly, thereby allowing otherwise unobservable wave-mixing resonances to be seen. This is an especially interesting phenomenon because these resonances are coherent effects that are induced by an incoherent process (collisional dephasing). First predicted in the late 1970s and eventually observed in 1981, these novel effects have now been seen in a wide variety of four-wave-mixing experiments, ranging from self-focusing to coherent anti-Stokes Raman spectroscopy. Recently, the authors have extended these observations to higher order, where the authors have shown both experimentally and theoretically the higher-order, collision-enhanced effects exist in nonlinear optics, appearing as subharmonics of two-photon resonances. Indeed, the authors have found that collision-enhanced processes are ideal systems for studying higher-order, nonlinear-optical effects because very high orders can be made to contribute with little or no saturation braodening. Experiments on sodium in a flame using six- and eight-wave-mixing geometries have revealed still higher-order effects (at least as high- order as χ (13) )
Lim, Cher Ping; Tay, Lee Yong
2003-01-01
Based on a case study of an elementary school in Singapore, this article describes and analyzes how different types of ICT tools (informative, situating, constructive, and communicative tools) are used to engage students in higher-order thinking. The discussion emphasizes that the objective of the lesson and the orienting activities, rather than…
Higher-Order Statistical Correlations and Mutual Information Among Particles in a Quantum Well
International Nuclear Information System (INIS)
Yépez, V. S.; Sagar, R. P.; Laguna, H. G.
2017-01-01
The influence of wave function symmetry on statistical correlation is studied for the case of three non-interacting spin-free quantum particles in a unidimensional box, in position and in momentum space. Higher-order statistical correlations occurring among the three particles in this quantum system is quantified via higher-order mutual information and compared to the correlation between pairs of variables in this model, and to the correlation in the two-particle system. The results for the higher-order mutual information show that there are states where the symmetric wave functions are more correlated than the antisymmetric ones with same quantum numbers. This holds in position as well as in momentum space. This behavior is opposite to that observed for the correlation between pairs of variables in this model, and the two-particle system, where the antisymmetric wave functions are in general more correlated. These results are also consistent with those observed in a system of three uncoupled oscillators. The use of higher-order mutual information as a correlation measure, is monitored and examined by considering a superposition of states or systems with two Slater determinants. (author)
Gamino, Jacquelyn F.; Chapman, Sandra B.; Cook, Lori G.
2009-01-01
Little is known about strategic learning ability in preteens and adolescents with traumatic brain injury (TBI). Strategic learning is the ability to combine and synthesize details to form abstracted gist-based meanings, a higher-order cognitive skill associated with frontal lobe functions and higher classroom performance. Summarization tasks were…
Second- and Higher-Order Virial Coefficients Derived from Equations of State for Real Gases
Parkinson, William A.
2009-01-01
Derivation of the second- and higher-order virial coefficients for models of the gaseous state is demonstrated by employing a direct differential method and subsequent term-by-term comparison to power series expansions. This communication demonstrates the application of this technique to van der Waals representations of virial coefficients.…
Quantum Noether identities for non-local transformations in higher-order derivatives theories
International Nuclear Information System (INIS)
Li, Z.P.; Long, Z.W.
2003-01-01
Based on the phase-space generating functional of the Green function for a system with a regular/singular higher-order Lagrangian, the quantum canonical Noether identities (NIs) under a local and non-local transformation in phase space have been deduced, respectively. For a singular higher-order Lagrangian, one must use an effective canonical action I eff P in quantum canonical NIs instead of the classical I P in classical canonical NIs. The quantum NIs under a local and non-local transformation in configuration space for a gauge-invariant system with a higher-order Lagrangian have also been derived. The above results hold true whether or not the Jacobian of the transformation is equal to unity or not. It has been pointed out that in certain cases the quantum NIs may be converted to conservation laws at the quantum level. This algorithm to derive the quantum conservation laws is significantly different from the quantum first Noether theorem. The applications of our formulation to the Yang-Mills fields and non-Abelian Chern-Simons (CS) theories with higher-order derivatives are given, and the conserved quantities at the quantum level for local and non-local transformations are found, respectively. (orig.)
Higher-Order Statistical Correlations and Mutual Information Among Particles in a Quantum Well
Yépez, V. S.; Sagar, R. P.; Laguna, H. G.
2017-12-01
The influence of wave function symmetry on statistical correlation is studied for the case of three non-interacting spin-free quantum particles in a unidimensional box, in position and in momentum space. Higher-order statistical correlations occurring among the three particles in this quantum system is quantified via higher-order mutual information and compared to the correlation between pairs of variables in this model, and to the correlation in the two-particle system. The results for the higher-order mutual information show that there are states where the symmetric wave functions are more correlated than the antisymmetric ones with same quantum numbers. This holds in position as well as in momentum space. This behavior is opposite to that observed for the correlation between pairs of variables in this model, and the two-particle system, where the antisymmetric wave functions are in general more correlated. These results are also consistent with those observed in a system of three uncoupled oscillators. The use of higher-order mutual information as a correlation measure, is monitored and examined by considering a superposition of states or systems with two Slater determinants.
Directory of Open Access Journals (Sweden)
Erkinjon Karimov
2017-10-01
Full Text Available In this work we discuss higher order multi-term partial differential equation (PDE with the Caputo-Fabrizio fractional derivative in time. Using method of separation of variables, we reduce fractional order partial differential equation to the integer order. We represent explicit solution of formulated problem in particular case by Fourier series.
Erkinjon Karimov; Sardor Pirnafasov
2017-01-01
In this work we discuss higher order multi-term partial differential equation (PDE) with the Caputo-Fabrizio fractional derivative in time. Using method of separation of variables, we reduce fractional order partial differential equation to the integer order. We represent explicit solution of formulated problem in particular case by Fourier series.
Tularam, Gurudeo Anand
2013-01-01
This paper addresses the importance of teaching mathematics in business and finance schools of tertiary institutions of Australia. The paper explores the nature of thinking and reasoning required for advancement financial or economic studies involves the use of higher order thinking and creativity skills (HOTS) for teaching in mathematics classes.…
Performance-Based Task Assessment of Higher-Order Proficiencies in Redesigned STEM High Schools
Ernst, Jeremy V.; Glennie, Elizabeth; Li, Songze
2017-01-01
This study explored student abilities in applying conceptual knowledge when presented with structured performance tasks. Specifically, the study gauged proficiency in higher-order applications of students enrolled in earth and environmental science or biology. The student sample was drawn from a Redesigned STEM high school model where a tested…
DEFF Research Database (Denmark)
Breinbjerg, Olav
1992-01-01
An approach for including higher order edge diffraction in the equivalent edge current (EEC) method is proposed. This approach, which applies to monostatic as well as bistatic radar configurations with perfectly conducting polygonal plates, involves three distinct sets of EECs. All of these sets...
Geometrical optics in general relativity: A study of the higher order corrections
International Nuclear Information System (INIS)
Anile, A.M.
1976-01-01
The higher order corrections to geometrical optics are studied in general relativity for an electromagnetic test wave. An explicit expression is found for the average energy--momentum tensor which takes into account the first-order corrections. Finally the first-order corrections to the well-known area-intensity law of geometrical optics are derived
Czech Academy of Sciences Publication Activity Database
Mukhigulashvili, Sulkhan; Půža, B.
2015-01-01
Roč. 2015, January (2015), s. 17 ISSN 1687-2770 Institutional support: RVO:67985840 Keywords : higher order nonlinear functional-differential equations * two-point right-focal boundary value problem * strong singularity Subject RIV: BA - General Mathematics Impact factor: 0.642, year: 2015 http://link.springer.com/article/10.1186%2Fs13661-014-0277-1
Superpositions of higher-order bessel beams and nondiffracting speckle fields - (SAIP 2009)
CSIR Research Space (South Africa)
Dudley, Angela L
2009-07-01
Full Text Available speckle fields. The paper reports on illuminating a ring slit aperture with light which has an azimuthal phase dependence, such that the field produced is a superposition of two higher-order Bessel beams. In the case that the phase dependence of the light...
H2O2-induced higher order chromatin degradation: A novel ...
Indian Academy of Sciences (India)
Unknown
mediator of oxidative stress, can also cause genomic damage indirectly. Thus, H2O2 at pathologically relevant concentrations rapidly induces higher order chromatin degradation (HOCD), i.e. enzymatic ... clease works through a single strand scission mechanism ... a great mutagenic risk to the surviving cells, because en-.
A Hybrid PO - Higher-Order Hierarchical MoM Formulation using Curvilinear Geometry Modeling
DEFF Research Database (Denmark)
Jørgensen, E.; Meincke, Peter; Breinbjerg, Olav
2003-01-01
which implies a very modest memory requirement. Nevertheless, the hierarchical feature of the basis functions maintains the ability to treat small geometrical details efficiently. In addition, the scatterer is modelled with higher-order curved patches which allows accurate modelling of curved surfaces...
Toledo, Santiago; Dubas, Justin M.
2016-01-01
An emphasis on higher-order thinking within the curriculum has been a subject of interest in the chemical and STEM literature due to its ability to promote meaningful, transferable learning in students. The systematic use of learning taxonomies could be a practical way to scaffold student learning in order to achieve this goal. This work proposes…
Higher-order multipole amplitude measurement in psi ' -> gamma chi(c2)
Ablikim, M.; Achasov, M. N.; Alberto, D.; An, F. F.; An, Q.; An, Z. H.; Bai, J. Z.; Baldini, R.; Ban, Y.; Becker, J.; Berger, N.; Bertani, M.; Bian, J. M.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Calcaterra, A. C.; Cao, G. F.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denysenko, I.; Destefanis, M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fang, J.; Fang, S. S.; Feng, C. Q.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Han, Y. L.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, B.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jia, L. K.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Kuehn, W.; Lai, W.; Lange, J. S.; Leung, J. K. C.; Li, C. H.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, K.; Li, Lei; Li, N. B.; Li, Q. J.; Li, S. L.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, X. T.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H.; Liu, H. B.; Liu, H. H.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K.; Liu, K. Y.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y. B.; Liu, Y. W.; Liu, Yong; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X.; Ma, X. Y.; Maggiora, M.; Malik, Q. A.; Mao, H.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Muchnoi, N. Yu; Nefedov, Y.; Nikolaev, I. B.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Park, J. W.; Pelizaeus, M.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pun, C. S. J.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. D.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tian, H. L.; Toth, D.; Varner, G. S.; Wang, B.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, Q. J.; Wang, S. G.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wen, Q. G.; Wen, S. P.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, W.; Wu, Z.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Q. J.; Xu, X. P.; Xu, Y.; Xu, Z. R.; Xu, Z. Z.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, T.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, S. P.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, S. H.; Zhang, T. R.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. S.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, Jiawei; Zhao, Jingwei; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhao, Z. L.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zheng, Z. P.; Zhong, B.; Zhong, J.; Zhong, L.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Zuo, J. X.
2011-01-01
Using 106 x 10(6) psi' events collected with the BESIII detector at the BEPCII storage ring, the higher-order multipole amplitudes in the radiative transition psi' -> gamma chi(c2) -> gamma pi(+)pi(-)/gamma K+K- are measured. A fit to the chi(c2) production and decay angular distributions yields M2
Unifying refinement and hoare-style reasoning in a logic for higher-order concurrency
DEFF Research Database (Denmark)
Turon, Aaron; Dreyer, Derek; Birkedal, Lars
2013-01-01
Modular programming and modular verification go hand in hand, but most existing logics for concurrency ignore two crucial forms of modularity: *higher-order functions*, which are essential for building reusable components, and *granularity abstraction*, a key technique for hiding the intricacies ...
Analysis of warping deformation modes using higher order ANCF beam element
Orzechowski, Grzegorz; Shabana, Ahmed A.
2016-02-01
Most classical beam theories assume that the beam cross section remains a rigid surface under an arbitrary loading condition. However, in the absolute nodal coordinate formulation (ANCF) continuum-based beams, this assumption can be relaxed allowing for capturing deformation modes that couple the cross-section deformation and beam bending, torsion, and/or elongation. The deformation modes captured by ANCF finite elements depend on the interpolating polynomials used. The most widely used spatial ANCF beam element employs linear approximation in the transverse direction, thereby restricting the cross section deformation and leading to locking problems. The objective of this investigation is to examine the behavior of a higher order ANCF beam element that includes quadratic interpolation in the transverse directions. This higher order element allows capturing warping and non-uniform stretching distribution. Furthermore, this higher order element allows for increasing the degree of continuity at the element interface. It is shown in this paper that the higher order ANCF beam element can be used effectively to capture warping and eliminate Poisson locking that characterizes lower order ANCF finite elements. It is also shown that increasing the degree of continuity requires a special attention in order to have acceptable results. Because higher order elements can be more computationally expensive than the lower order elements, the use of reduced integration for evaluating the stress forces and the use of explicit and implicit numerical integrations to solve the nonlinear dynamic equations of motion are investigated in this paper. It is shown that the use of some of these integration methods can be very effective in reducing the CPU time without adversely affecting the solution accuracy.
Martin, Joyce A; Hamilton, Brady E; Sutton, Paul D; Ventura, Stephanie J; Menacker, Fay; Kirmeyer, Sharon
2006-09-29
. The twinning rate increased, but the rate of triplet and higher order multiple births was down slightly.
Scott, Kristin M; Barbarin, Oscar A; Brown, Jeffrey M
2013-01-01
This study examines the relations of higher order (i.e., abstract) thinking (HOT) skills to specific domains of social competence in Black boys (n = 108) attending publicly sponsored prekindergarten (pre-K) programs. Data for the study were collected as part of the National Center for Early Development and Learning (NCEDL) Multi-State Study, a national, longitudinal study examining the quality and outcomes in a representative sample of publicly sponsored pre-K programs in six states (N = 240). Pre-K and kindergarten teachers rated randomly selected children on measures of abstract thinking, self-regulation, and social functioning at the beginning and end of each school year. Applying structural equation modeling, compared with earlier time points, HOT measured in the fall of kindergarten significantly predicted each of the domains of social competence in the spring of kindergarten, with the exception of peer social skills, while controlling for general cognitive ability. Results suggest that early intervention to improve HOT may be an effective and more focused approach to address concerns about Black boys' early social competencies in specific domains and potentially reduce the risk of later social difficulties. © 2013 American Orthopsychiatric Association.
Bulgren, Janis; Deshler, Donald D; Lenz, B Keith
2007-01-01
The understanding and use of historical concepts specified in national history standards pose many challenges to students. These challenges include both the acquisition of content knowledge and the use of that knowledge in ways that require higher order thinking. All students, including adolescents with learning disabilities (LD), are expected to understand and use concepts of history to pass high-stakes assessments and to participate meaningfully in a democratic society. This article describes Content Enhancement Routines (CERs) to illustrate instructional planning, teaching, and assessing for higher order thinking with examples from an American history unit. Research on the individual components of Content Enhancement Routines will be illustrated with data from 1 of the routines. The potential use of integrated sets of materials and procedures across grade levels and content areas will be discussed.
A Study of Enhanced, Higher Order Boussinesq-Type Equations and Their Numerical Modelling
DEFF Research Database (Denmark)
Banijamali, Babak
model is designated for the solution of higher-order Boussinesq-type equations, formulated in terms of the horizontal velocity at an arbitrary depth vector. Various discretisation techniques and grid definitions have been considered in this endeavour, undertaking a detailed analysis of the selected......This project has encompassed efforts in two separate veins: on the one hand, the acquiring of highly accurate model equations of the Boussinesq-type, and on the other hand, the theoretical and practical work in implementing such equations in the form of conventional numerical models, with obvious...... potential for applications to the realm of numerical modelling in coastal engineering. The derivation and analysis of several forms of higher-order in dispersion and non-linearity Boussinesq-type equations have been undertaken, obtaining and investigating the properties of a new and generalised class...
Sapriadil, S.; Setiawan, A.; Suhandi, A.; Malik, A.; Safitri, D.; Lisdiani, S. A. S.; Hermita, N.
2018-05-01
Communication skill is one skill that is very needed in this 21st century. Preparing and teaching this skill in teaching physics is relatively important. The focus of this research is to optimizing of students’ scientific communication skills after the applied higher order thinking virtual laboratory (HOTVL) on topic electric circuit. This research then employed experimental study particularly posttest-only control group design. The subject in this research involved thirty senior high school students which were taken using purposive sampling. A sample of seventy (70) students participated in the research. An equivalent number of thirty five (35) students were assigned to the control and experimental group. The results of this study found that students using higher order thinking virtual laboratory (HOTVL) in laboratory activities had higher scientific communication skills than students who used the verification virtual lab.
An initial framework for the language of higher-order thinking mathematics practices
Staples, Megan E.; Truxaw, Mary P.
2012-09-01
This article presents an examination of the language demands of cognitively demanding tasks and proposes an initial framework for the language demands of higher-order mathematics thinking practices. We articulate four categories for this framework: language of generalisation, language of comparison, language of proportional reasoning, and language of analysing impact. These categories were developed out of our collaborative work to design and implement higher-order thinking tasks with a group of Grade 9 (14- and 15-year-olds) teachers teaching in a linguistically diverse setting; analyses of student work samples on these tasks; and our knowledge of the literature. We describe each type of language demand and then analyse student work in each category to reveal linguistic challenges facing students as they engage these mathematical tasks. Implications for teaching and professional development are discussed.
An Efficient Higher-Order Quasilinearization Method for Solving Nonlinear BVPs
Directory of Open Access Journals (Sweden)
Eman S. Alaidarous
2013-01-01
Full Text Available In this research paper, we present higher-order quasilinearization methods for the boundary value problems as well as coupled boundary value problems. The construction of higher-order convergent methods depends on a decomposition method which is different from Adomain decomposition method (Motsa and Sibanda, 2013. The reported method is very general and can be extended to desired order of convergence for highly nonlinear differential equations and also computationally superior to proposed iterative method based on Adomain decomposition because our proposed iterative scheme avoids the calculations of Adomain polynomials and achieves the same computational order of convergence as authors have claimed in Motsa and Sibanda, 2013. In order to check the validity and computational performance, the constructed iterative schemes are also successfully applied to bifurcation problems to calculate the values of critical parameters. The numerical performance is also tested for one-dimension Bratu and Frank-Kamenetzkii equations.
Evidence for higher-order effects in L-shell ionization by proton impact
International Nuclear Information System (INIS)
Sarkadi, L.; Mukoyama, T.
1988-01-01
It is widely believed that higher order processes of ion-atom collisions are negligible in cases of light projectiles like proton. Recent refined experiments tried to prove that the existence of such effects were comperable with the experimental errors, and they showed the unexpected relative importance of the higher order processes. Thus a new coupled channel calculation was performed for proton-gold atom collision in the energy range of 0.15-3.0 MeV, including dynamical subshell coupling effects. The results show that the deviations from the first order cross sections reach 40% at low collision energy. This result made necessary to correct the calculations of L-shell X-ray production cross sections. (D.G.) 6 refs
Higher-order meshing of implicit geometries, Part II: Approximations on manifolds
Fries, T. P.; Schöllhammer, D.
2017-11-01
A new concept for the higher-order accurate approximation of partial differential equations on manifolds is proposed where a surface mesh composed by higher-order elements is automatically generated based on level-set data. Thereby, it enables a completely automatic workflow from the geometric description to the numerical analysis without any user-intervention. A master level-set function defines the shape of the manifold through its zero-isosurface which is then restricted to a finite domain by additional level-set functions. It is ensured that the surface elements are sufficiently continuous and shape regular which is achieved by manipulating the background mesh. The numerical results show that optimal convergence rates are obtained with a moderate increase in the condition number compared to handcrafted surface meshes.
International Nuclear Information System (INIS)
Vogt, A; Soar, G.; Vermaseren, J.A.M.
2010-01-01
We have studied the physical evolution kernels for nine non-singlet observables in deep-inelastic scattering (DIS), semi-inclusive e + e - annihilation and the Drell-Yan (DY) process, and for the flavour-singlet case of the photon- and heavy-top Higgs-exchange structure functions (F 2 , F φ ) in DIS. All known contributions to these kernels show an only single-logarithmic large-x enhancement at all powers of (1-x). Conjecturing that this behaviour persists to (all) higher orders, we have predicted the highest three (DY: two) double logarithms of the higher-order non-singlet coefficient functions and of the four-loop singlet splitting functions. The coefficient-function predictions can be written as exponentiations of 1/N-suppressed contributions in Mellin-N space which, however, are less predictive than the well-known exponentiation of the ln k N terms. (orig.)
ANOVA-HDMR structure of the higher order nodal diffusion solution
International Nuclear Information System (INIS)
Bokov, P. M.; Prinsloo, R. H.; Tomasevic, D. I.
2013-01-01
Nodal diffusion methods still represent a standard in global reactor calculations, but employ some ad-hoc approximations (such as the quadratic leakage approximation) which limit their accuracy in cases where reference quality solutions are sought. In this work we solve the nodal diffusion equations utilizing the so-called higher-order nodal methods to generate reference quality solutions and to decompose the obtained solutions via a technique known as High Dimensional Model Representation (HDMR). This representation and associated decomposition of the solution provides a new formulation of the transverse leakage term. The HDMR structure is investigated via the technique of Analysis of Variance (ANOVA), which indicates why the existing class of transversely-integrated nodal methods prove to be so successful. Furthermore, the analysis leads to a potential solution method for generating reference quality solutions at a much reduced calculational cost, by applying the ANOVA technique to the full higher order solution. (authors)
Higher-Order Structure in Bacterial VapBC Toxin-Antitoxin Complexes
DEFF Research Database (Denmark)
Bendtsen, Kirstine L; Brodersen, Ditlev E
2017-01-01
Toxin-antitoxin systems are widespread in the bacterial kingdom, including in pathogenic species, where they allow rapid adaptation to changing environmental conditions through selective inhibition of key cellular processes, such as DNA replication or protein translation. Under normal growth...... that allow auto-regulation of transcription by direct binding to promoter DNA. In this chapter, we review our current understanding of the structural characteristics of type II toxin-antitoxin complexes in bacterial cells, with a special emphasis on the staggering variety of higher-order architecture...... conditions, type II toxins are inhibited through tight protein-protein interaction with a cognate antitoxin protein. This toxin-antitoxin complex associates into a higher-order macromolecular structure, typically heterotetrameric or heterooctameric, exposing two DNA binding domains on the antitoxin...
Coaxial higher-order mode damper employing a high-pass filter
International Nuclear Information System (INIS)
Kang, Y.W.; Jiang, X.
1997-01-01
Two different types of coaxial higher-order mode (HOM) dampers have been investigated for the Advanced Photon Source (APS) storage ring cavities: e-probe dampers and h-loop dampers. Realization of the h-loop dampers has been difficult because the loop antenna couples not only to the HOMs but also to the accelerating mode and results in loss of Q at the fundamental frequency. Previously, a first-order fundamental rejection filter was tested with unsatisfactory rejection characteristics. This problem can be overcome by using a higher-order high-pass filter between the loop and the matched load. Prototype dampers have been fabricated and tested in a storage ring single-cell cavity and the damping characteristic was analyzed
Gill, Tarsem Singh; Kaur, Ravinder; Mahajan, Ranju
2010-09-01
This paper presents an analysis of self-consistent, steady-state, theoretical model, which explains the ring formation in a Gaussian electromagnetic beam propagating in a magnetoplasma, characterized by relativistic nonlinearity. Higher order terms (up to r4) in the expansion of the dielectric function and the eikonal have been taken into account. The condition for the formation of a dark and bright ring derived earlier by Misra and Mishra [J. Plasma Phys. 75, 769 (2009)] has been used to study focusing/defocusing of the beam. It is seen that inclusion of higher order terms does significantly affect the dependence of the beam width on the distance of propagation. Further, the effect of the magnetic field and the nature of nonlinearity on the ring formation and self-focusing of the beam have been explored.
International Nuclear Information System (INIS)
Gill, Tarsem Singh; Kaur, Ravinder; Mahajan, Ranju
2010-01-01
This paper presents an analysis of self-consistent, steady-state, theoretical model, which explains the ring formation in a Gaussian electromagnetic beam propagating in a magnetoplasma, characterized by relativistic nonlinearity. Higher order terms (up to r 4 ) in the expansion of the dielectric function and the eikonal have been taken into account. The condition for the formation of a dark and bright ring derived earlier by Misra and Mishra [J. Plasma Phys. 75, 769 (2009)] has been used to study focusing/defocusing of the beam. It is seen that inclusion of higher order terms does significantly affect the dependence of the beam width on the distance of propagation. Further, the effect of the magnetic field and the nature of nonlinearity on the ring formation and self-focusing of the beam have been explored.
Robust rooftop extraction from visible band images using higher order CRF
Li, Er
2015-08-01
In this paper, we propose a robust framework for building extraction in visible band images. We first get an initial classification of the pixels based on an unsupervised presegmentation. Then, we develop a novel conditional random field (CRF) formulation to achieve accurate rooftops extraction, which incorporates pixel-level information and segment-level information for the identification of rooftops. Comparing with the commonly used CRF model, a higher order potential defined on segment is added in our model, by exploiting region consistency and shape feature at segment level. Our experiments show that the proposed higher order CRF model outperforms the state-of-the-art methods both at pixel and object levels on rooftops with complex structures and sizes in challenging environments. © 1980-2012 IEEE.
John Carroll’s Views on Intelligence: Bi-Factor vs. Higher-Order Models
Directory of Open Access Journals (Sweden)
A. Alexander Beaujean
2015-10-01
Full Text Available The development of factor models is inextricably tied to the history of intelligence research. One of the most commonly-cited scholars in the field is John Carroll, whose three-stratum theory of cognitive ability has been one of the most influential models of cognitive ability in the past 20 years. Nonetheless, there is disagreement about how Carroll conceptualized the factors in his model. Some argue that his model is best represented through a higher-order model, while others argue that a bi-factor model is a better representation. Carroll was explicit about what he perceived the best way to represent his model, but his writings are not always easy to understand. In this article, I clarify his position by first describing the details and implications of bi-factor and higher-order models then show that Carroll’s published views are better represented by a bi-factor model.
A higher order space-time Galerkin scheme for time domain integral equations
Pray, Andrew J.; Beghein, Yves; Nair, Naveen V.; Cools, Kristof; Bagci, Hakan; Shanker, Balasubramaniam
2014-01-01
Stability of time domain integral equation (TDIE) solvers has remained an elusive goal formany years. Advancement of this research has largely progressed on four fronts: 1) Exact integration, 2) Lubich quadrature, 3) smooth temporal basis functions, and 4) space-time separation of convolutions with the retarded potential. The latter method's efficacy in stabilizing solutions to the time domain electric field integral equation (TD-EFIE) was previously reported for first-order surface descriptions (flat elements) and zeroth-order functions as the temporal basis. In this work, we develop the methodology necessary to extend the scheme to higher order surface descriptions as well as to enable its use with higher order basis functions in both space and time. These basis functions are then used in a space-time Galerkin framework. A number of results are presented that demonstrate convergence in time. The viability of the space-time separation method in producing stable results is demonstrated experimentally for these examples.
Discrete Maximum Principle for Higher-Order Finite Elements in 1D
Czech Academy of Sciences Publication Activity Database
Vejchodský, Tomáš; Šolín, Pavel
2007-01-01
Roč. 76, č. 260 (2007), s. 1833-1846 ISSN 0025-5718 R&D Projects: GA ČR GP201/04/P021 Institutional research plan: CEZ:AV0Z10190503; CEZ:AV0Z20760514 Keywords : discrete maximum principle * discrete Grren´s function * higher-order elements Subject RIV: BA - General Mathematics Impact factor: 1.230, year: 2007
Tunnelling effects of solitons in optical fibers with higher-order effects
Energy Technology Data Exchange (ETDEWEB)
Dai, Chao-Qing [Zhejiang A and F Univ., Lin' an (China). School of Sciences; Suzhou Univ., Jiangsu (China). School of Physical Science and Technology; Zhu, Hai-Ping [Zhejiang Lishui Univ., Zhejiang (China). School of Science; Zheng, Chun-Long [Shaoguan Univ., Guangdong (China). College of Physics and Electromechanical Engineering
2012-06-15
We construct four types of analytical soliton solutions for the higher-order nonlinear Schroedinger equation with distributed coefficients. These solutions include bright solitons, dark solitons, combined solitons, and M-shaped solitons. Moreover, the explicit functions which describe the evolution of the width, peak, and phase are discussed exactly. We finally discuss the nonlinear soliton tunnelling effect for four types of femtosecond solitons. (orig.)
International Nuclear Information System (INIS)
Shi Yi; Nanjing Univ., JS; Wu Fengmei; Nanjing Univ., JS; Zheng Youdou; Nanjing Univ., JS; Suezawa, M.; Imai, M.; Sumino, K.
1996-01-01
Optically active processes of the higher-order bands (HOB) are investigated at different temperatures in fast neutron irradiated silicon using Fourier transform infrared absorption measurement. It is shown that the optically active process is nearly temperature independent below 80 K, the slow decay process remains up to a heating temperature of 180 K. The observations are analyzed in terms of the relaxation behavior of photoexcited carriers governed by fast neutron radiation induced defect clusters. (orig.)
Dynamic Correction of Higher-Order Deflection Aberrations in the Environmental SEM
Czech Academy of Sciences Publication Activity Database
Oral, Martin; Neděla, Vilém
2015-01-01
Roč. 21, S4 (2015), s. 194-199 ISSN 1431-9276 R&D Projects: GA ČR(CZ) GA14-22777S; GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : environmental SEM * ESEM * shifted deflection pivot point * Higher order deflection aberrations * vignetting * dynamic focusing * dynamic stigmator * dynamic correction Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.730, year: 2015
Asymptotic estimates and exponential stability for higher-order monotone difference equations
Directory of Open Access Journals (Sweden)
Pituk Mihály
2005-01-01
Full Text Available Asymptotic estimates are established for higher-order scalar difference equations and inequalities the right-hand sides of which generate a monotone system with respect to the discrete exponential ordering. It is shown that in some cases the exponential estimates can be replaced with a more precise limit relation. As corollaries, a generalization of discrete Halanay-type inequalities and explicit sufficient conditions for the global exponential stability of the zero solution are given.
Asymptotic estimates and exponential stability for higher-order monotone difference equations
Directory of Open Access Journals (Sweden)
Mihály Pituk
2005-03-01
Full Text Available Asymptotic estimates are established for higher-order scalar difference equations and inequalities the right-hand sides of which generate a monotone system with respect to the discrete exponential ordering. It is shown that in some cases the exponential estimates can be replaced with a more precise limit relation. As corollaries, a generalization of discrete Halanay-type inequalities and explicit sufficient conditions for the global exponential stability of the zero solution are given.
A single dose of oxytocin nasal spray improves higher-order social cognition in schizophrenia.
Guastella, Adam J; Ward, Philip B; Hickie, Ian B; Shahrestani, Sara; Hodge, Marie Antoinette Redoblado; Scott, Elizabeth M; Langdon, Robyn
2015-11-01
Schizophrenia is associated with significant impairments in both higher and lower order social cognitive performance and these impairments contribute to poor social functioning. People with schizophrenia report poor social functioning to be one of their greatest unmet treatment needs. Recent studies have suggested the potential of oxytocin as such a treatment, but mixed results render it uncertain what aspects of social cognition are improved by oxytocin and, subsequently, how oxytocin might best be applied as a therapeutic. The aim of this study was to determine whether a single dose of oxytocin improved higher-order and lower-order social cognition performance for patients with schizophrenia across a well-established battery of social cognition tests. Twenty-one male patients received both a single dose of oxytocin nasal spray (24IU) and a placebo, two weeks apart in a randomized within-subjects placebo controlled design. Following each administration, participants completed the social cognition tasks, as well as a test of general neurocognition. Results revealed that oxytocin particularly enhanced performance on higher order social cognition tasks, with no effects on general neurocognition. Results for individual tasks showed most improvement on tests measuring appreciation of indirect hints and recognition of social faux pas. These results suggest that oxytocin, if combined to enhance social cognition learning, may be beneficial when targeted at higher order social cognition domains. This study also suggests that these higher order tasks, which assess social cognitive processing in a social communication context, may provide useful markers of response to oxytocin in schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.
Combined solitary-wave solution for coupled higher-order nonlinear Schroedinger equations
International Nuclear Information System (INIS)
Tian Jinping; Tian Huiping; Li Zhonghao; Zhou Guosheng
2004-01-01
Coupled nonlinear Schroedinger equations model several interesting physical phenomena. We used a trigonometric function transform method based on a homogeneous balance to solve the coupled higher-order nonlinear Schroedinger equations. We obtained four pairs of exact solitary-wave solutions including a dark and a bright-soliton pair, a bright- and a dark-soliton pair, a bright- and a bright-soliton pair, and the last pair, a combined bright-dark-soliton pair
On the mild solutions of higher-order differential equations in Banach spaces
Directory of Open Access Journals (Sweden)
Nguyen Thanh Lan
2003-01-01
Full Text Available For the higher-order abstract differential equation u(n(t=Au(t+f(t, t∈ℝ, we give a new definition of mild solutions. We then characterize the regular admissibility of a translation-invariant subspace ℳ of BUC(ℝ,E with respect to the above-mentioned equation in terms of solvability of the operator equation AX−Xn=C. As applications, periodicity and almost periodicity of mild solutions are also proved.
Tiruneh, Ababu Teklemariam
2013-01-01
Aitken extrapolation normally applied to convergent fixed point iteration is extended to extrapolate the solution of a divergent iteration. In addition, higher order Aitken extrapolation is introduced that enables successive decomposition of high Eigen values of the iteration matrix to enable convergence. While extrapolation of a convergent fixed point iteration using a geometric series sum is a known form of Aitken acceleration, it is shown in this paper that the same formula can be used to ...
Exotic quantum holonomy and higher-order exceptional points in quantum kicked tops
Tanaka, Atushi; Kim, Sang Wook; Cheon, Taksu
2014-01-01
The correspondence between exotic quantum holonomy that occurs in families of Hermitian cycles, and exceptional points (EPs) for non-Hermitian quantum theory is examined in quantum kicked tops. Under a suitable condition, an explicit expressions of the adiabatic parameter dependencies of quasienergies and stationary states, which exhibit anholonomies, are obtained. It is also shown that the quantum kicked tops with the complexified adiabatic parameter have a higher order EP, which is broken i...
Growth of meromorphic solutions of higher-order linear differential equations
Directory of Open Access Journals (Sweden)
Wenjuan Chen
2009-01-01
Full Text Available In this paper, we investigate the higher-order linear differential equations with meromorphic coefficients. We improve and extend a result of M.S. Liu and C.L. Yuan, by using the estimates for the logarithmic derivative of a transcendental meromorphic function due to Gundersen, and the extended Winman-Valiron theory which proved by J. Wang and H.X. Yi. In addition, we also consider the nonhomogeneous linear differential equations.
Soliton and periodic solutions for higher order wave equations of KdV type (I)
International Nuclear Information System (INIS)
Khuri, S.A.
2005-01-01
The aim of the paper is twofold. First, a new ansaetze is introduced for the construction of exact solutions for higher order wave equations of KdV type (I). We show the existence of a class of discontinuous soliton solutions with infinite spikes. Second, the projective Riccati technique is implemented as an alternate approach for obtaining new exact solutions, solitary solutions, and periodic wave solutions
Contribution of higher order terms in the reductive perturbation theory, 2
International Nuclear Information System (INIS)
Ichikawa, Y.H.; Mitsuhashi, Teruo; Konno, Kimiaki.
1977-01-01
Contribution of higher order terms in the reductive perturbation theory has been investigated for nonlinear propagation of strongly dispersive ion plasma wave. The basic set of fluid equation is reduced to a coupled set of the nonlinear Schroedinger equation for the first order perturbed potential and a linear inhomogeneous equation for the second order perturbed potential. A steady state solution of the coupled set of equations has been solved analytically in the asymptotic limit of small wave number. (auth.)
Transition, coexistence, and interaction of vector localized waves arising from higher-order effects
International Nuclear Information System (INIS)
Liu, Chong; Yang, Zhan-Ying; Zhao, Li-Chen; Yang, Wen-Li
2015-01-01
We study vector localized waves on continuous wave background with higher-order effects in a two-mode optical fiber. The striking properties of transition, coexistence, and interaction of these localized waves arising from higher-order effects are revealed in combination with corresponding modulation instability (MI) characteristics. It shows that these vector localized wave properties have no analogues in the case without higher-order effects. Specifically, compared to the scalar case, an intriguing transition between bright–dark rogue waves and w-shaped–anti-w-shaped solitons, which occurs as a result of the attenuation of MI growth rate to vanishing in the zero-frequency perturbation region, is exhibited with the relative background frequency. In particular, our results show that the w-shaped–anti-w-shaped solitons can coexist with breathers, coinciding with the MI analysis where the coexistence condition is a mixture of a modulation stability and MI region. It is interesting that their interaction is inelastic and describes a fusion process. In addition, we demonstrate an annihilation phenomenon for the interaction of two w-shaped solitons which is identified essentially as an inelastic collision in this system. -- Highlights: •Vector rogue wave properties induced by higher-order effects are studied. •A transition between vector rogue waves and solitons is obtained. •The link between the transition and modulation instability (MI) is demonstrated. •The coexistence of vector solitons and breathers coincides with the MI features. •An annihilation phenomenon for the vector two w-shaped solitons is presented.
Transition, coexistence, and interaction of vector localized waves arising from higher-order effects
Energy Technology Data Exchange (ETDEWEB)
Liu, Chong [School of Physics, Northwest University, Xi’an 710069 (China); Yang, Zhan-Ying, E-mail: zyyang@nwu.edu.cn [School of Physics, Northwest University, Xi’an 710069 (China); Zhao, Li-Chen, E-mail: zhaolichen3@163.com [School of Physics, Northwest University, Xi’an 710069 (China); Yang, Wen-Li [Institute of Modern Physics, Northwest University, Xi’an 710069 (China)
2015-11-15
We study vector localized waves on continuous wave background with higher-order effects in a two-mode optical fiber. The striking properties of transition, coexistence, and interaction of these localized waves arising from higher-order effects are revealed in combination with corresponding modulation instability (MI) characteristics. It shows that these vector localized wave properties have no analogues in the case without higher-order effects. Specifically, compared to the scalar case, an intriguing transition between bright–dark rogue waves and w-shaped–anti-w-shaped solitons, which occurs as a result of the attenuation of MI growth rate to vanishing in the zero-frequency perturbation region, is exhibited with the relative background frequency. In particular, our results show that the w-shaped–anti-w-shaped solitons can coexist with breathers, coinciding with the MI analysis where the coexistence condition is a mixture of a modulation stability and MI region. It is interesting that their interaction is inelastic and describes a fusion process. In addition, we demonstrate an annihilation phenomenon for the interaction of two w-shaped solitons which is identified essentially as an inelastic collision in this system. -- Highlights: •Vector rogue wave properties induced by higher-order effects are studied. •A transition between vector rogue waves and solitons is obtained. •The link between the transition and modulation instability (MI) is demonstrated. •The coexistence of vector solitons and breathers coincides with the MI features. •An annihilation phenomenon for the vector two w-shaped solitons is presented.
Sleep inertia, sleep homeostatic and circadian influences on higher-order cognitive functions.
Burke, Tina M; Scheer, Frank A J L; Ronda, Joseph M; Czeisler, Charles A; Wright, Kenneth P
2015-08-01
Sleep inertia, sleep homeostatic and circadian processes modulate cognition, including reaction time, memory, mood and alertness. How these processes influence higher-order cognitive functions is not well known. Six participants completed a 73-day-long study that included two 14-day-long 28-h forced desynchrony protocols to examine separate and interacting influences of sleep inertia, sleep homeostasis and circadian phase on higher-order cognitive functions of inhibitory control and selective visual attention. Cognitive performance for most measures was impaired immediately after scheduled awakening and improved during the first ~2-4 h of wakefulness (decreasing sleep inertia); worsened thereafter until scheduled bedtime (increasing sleep homeostasis); and was worst at ~60° and best at ~240° (circadian modulation, with worst and best phases corresponding to ~09:00 and ~21:00 hours, respectively, in individuals with a habitual wake time of 07:00 hours). The relative influences of sleep inertia, sleep homeostasis and circadian phase depended on the specific higher-order cognitive function task examined. Inhibitory control appeared to be modulated most strongly by circadian phase, whereas selective visual attention for a spatial-configuration search task was modulated most strongly by sleep inertia. These findings demonstrate that some higher-order cognitive processes are differentially sensitive to different sleep-wake regulatory processes. Differential modulation of cognitive functions by different sleep-wake regulatory processes has important implications for understanding mechanisms contributing to performance impairments during adverse circadian phases, sleep deprivation and/or upon awakening from sleep. © 2015 European Sleep Research Society.
Wilson's theory of critical phenomena. Higher order corrections to critical exponents
International Nuclear Information System (INIS)
Zinn-Justin, J.
1973-01-01
The Wilson's theory of critical phenomena is presented, in the context of renormalized field theory in d dimension and of the Callan-Symanzik equations. This theory allows in particular to compute critical exponents that govern the behavior of some correlation functions near the critical temperature, as power series in epsilon=4-d, using the standard perturbation theory. Owing to the large value of the expansion parameter epsilon, whose physical value is one, it is very important to perform higher order calculations [fr
A stable higher order space time Galerkin marching-on-in-time scheme
Pray, Andrew J.
2013-07-01
We present a method for the stable solution of time-domain integral equations. The method uses a technique developed in [1] to accurately evaluate matrix elements. As opposed to existing stabilization schemes, the method presented uses higher order basis functions in time to improve the accuracy of the solver. The method is validated by showing convergence in temporal basis function order, time step size, and geometric discretization order. © 2013 IEEE.
Integrated Software Development System/Higher Order Software Conceptual Description (ISDS/HOS)
1976-11-01
Structured Flowchart Conventions 270 6.3.5.3 Design Diagram Notation 273 xii HIGHER ORDER SOFTWARE, INC. 843 MASSACHUSETTS AVENUE. CAMBRIDGE, MASSACHUSETTS...associated with the process steps. They also reference other HIPO diagrams as well an non-HIPO documentation such as flowcharts or decision tables of...syntax that is easy to learn and must provide the novice with some prompting to help him avoid classic beginner errors. Desirable editing capabilities
Energy Technology Data Exchange (ETDEWEB)
Pal' chikov, V.G. [National Research Institute for Physical-Technical and Radiotechnical Measurements - VNIIFTRI (Russian Federation)], E-mail: vitpal@mail.ru
2000-08-15
A quantum-electrodynamical (QED) perturbation theory is developed for hydrogen and hydrogen-like atomic systems with interaction between bound electrons and radiative field being treated as the perturbation. The dependence of the perturbed energy of levels on hyperfine structure (hfs) effects and on the higher-order Stark effect is investigated. Numerical results have been obtained for the transition probability between the hfs components of hydrogen-like bismuth.
Optimizing of the higher order mode dampers in the 56MHz SRF cavity
International Nuclear Information System (INIS)
Wu, Q.; Ben-Zvi, I.
2010-01-01
Earlier, we reported that a 56 MHz cavity was designed for a luminosity upgrade of the RHIC, and presented the requirements for Higher Order Mode (HOM) damping, the design of the HOM dampers, along with measurements and simulations of the HOM dampers. In this report, we describe our optimization of the dampers performance, and the modifications we made to their original design. We also optimized the number of the HOM dampers, and tested different configurations of locations for them.
A Frank mixture copula family for modeling higher-order correlations of neural spike counts
International Nuclear Information System (INIS)
Onken, Arno; Obermayer, Klaus
2009-01-01
In order to evaluate the importance of higher-order correlations in neural spike count codes, flexible statistical models of dependent multivariate spike counts are required. Copula families, parametric multivariate distributions that represent dependencies, can be applied to construct such models. We introduce the Frank mixture family as a new copula family that has separate parameters for all pairwise and higher-order correlations. In contrast to the Farlie-Gumbel-Morgenstern copula family that shares this property, the Frank mixture copula can model strong correlations. We apply spike count models based on the Frank mixture copula to data generated by a network of leaky integrate-and-fire neurons and compare the goodness of fit to distributions based on the Farlie-Gumbel-Morgenstern family. Finally, we evaluate the importance of using proper single neuron spike count distributions on the Shannon information. We find notable deviations in the entropy that increase with decreasing firing rates. Moreover, we find that the Frank mixture family increases the log likelihood of the fit significantly compared to the Farlie-Gumbel-Morgenstern family. This shows that the Frank mixture copula is a useful tool to assess the importance of higher-order correlations in spike count codes.
Symmetries, invariants and generating functions: higher-order statistics of biased tracers
Munshi, Dipak
2018-01-01
Gravitationally collapsed objects are known to be biased tracers of an underlying density contrast. Using symmetry arguments, generalised biasing schemes have recently been developed to relate the halo density contrast δh with the underlying density contrast δ, divergence of velocity θ and their higher-order derivatives. This is done by constructing invariants such as s, t, ψ,η. We show how the generating function formalism in Eulerian standard perturbation theory (SPT) can be used to show that many of the additional terms based on extended Galilean and Lifshitz symmetry actually do not make any contribution to the higher-order statistics of biased tracers. Other terms can also be drastically simplified allowing us to write the vertices associated with δh in terms of the vertices of δ and θ, the higher-order derivatives and the bias coefficients. We also compute the cumulant correlators (CCs) for two different tracer populations. These perturbative results are valid for tree-level contributions but at an arbitrary order. We also take into account the stochastic nature bias in our analysis. Extending previous results of a local polynomial model of bias, we express the one-point cumulants Script SN and their two-point counterparts, the CCs i.e. Script Cpq, of biased tracers in terms of that of their underlying density contrast counterparts. As a by-product of our calculation we also discuss the results using approximations based on Lagrangian perturbation theory (LPT).
Higher-order neural network software for distortion invariant object recognition
Reid, Max B.; Spirkovska, Lilly
1991-01-01
The state-of-the-art in pattern recognition for such applications as automatic target recognition and industrial robotic vision relies on digital image processing. We present a higher-order neural network model and software which performs the complete feature extraction-pattern classification paradigm required for automatic pattern recognition. Using a third-order neural network, we demonstrate complete, 100 percent accurate invariance to distortions of scale, position, and in-plate rotation. In a higher-order neural network, feature extraction is built into the network, and does not have to be learned. Only the relatively simple classification step must be learned. This is key to achieving very rapid training. The training set is much smaller than with standard neural network software because the higher-order network only has to be shown one view of each object to be learned, not every possible view. The software and graphical user interface run on any Sun workstation. Results of the use of the neural software in autonomous robotic vision systems are presented. Such a system could have extensive application in robotic manufacturing.
Higher-order stochastic differential equations and the positive Wigner function
Drummond, P. D.
2017-12-01
General higher-order stochastic processes that correspond to any diffusion-type tensor of higher than second order are obtained. The relationship of multivariate higher-order stochastic differential equations with tensor decomposition theory and tensor rank is explained. Techniques for generating the requisite complex higher-order noise are proved to exist either using polar coordinates and γ distributions, or from products of Gaussian variates. This method is shown to allow the calculation of the dynamics of the Wigner function, after it is extended to a complex phase space. The results are illustrated physically through dynamical calculations of the positive Wigner distribution for three-mode parametric downconversion, widely used in quantum optics. The approach eliminates paradoxes arising from truncation of the higher derivative terms in Wigner function time evolution. Anomalous results of negative populations and vacuum scattering found in truncated Wigner quantum simulations in quantum optics and Bose-Einstein condensate dynamics are shown not to occur with this type of stochastic theory.
Security Analysis of 7-Round MISTY1 against Higher Order Differential Attacks
Tsunoo, Yukiyasu; Saito, Teruo; Shigeri, Maki; Kawabata, Takeshi
MISTY1 is a 64-bit block cipher that has provable security against differential and linear cryptanalysis. MISTY1 is one of the algorithms selected in the European NESSIE project, and it has been recommended for Japanese e-Government ciphers by the CRYPTREC project. This paper shows that higher order differential attacks can be successful against 7-round versions of MISTY1 with FL functions. The attack on 7-round MISTY1 can recover a partial subkey with a data complexity of 254.1 and a computational complexity of 2120.8, which signifies the first successful attack on 7-round MISTY1 with no limitation such as a weak key. This paper also evaluates the complexity of this higher order differential attack on MISTY1 in which the key schedule is replaced by a pseudorandom function. It is shown that resistance to the higher order differential attack is not substantially improved even in 7-round MISTY1 in which the key schedule is replaced by a pseudorandom function.
Educating Grade 6 students for higher-order thinking and its influence on creativity
Directory of Open Access Journals (Sweden)
Wajeeh Daher
2017-08-01
Full Text Available Educating students for higher-order thinking provides them with tools that turn them into more critical thinkers. This supports them in overcoming life problems that they encounter, as well as becoming an integral part of the society. This students’ education is attended to by educational organisations that emphasise the positive consequences of educating students for higher-order thinking, including creative thinking. One way to do that is through educational programmes that educate for higher-order thinking. One such programme is the Cognitive Research Trust (CoRT thinking programme. The present research intended to examine the effect of the participation of Grade 6 students in a CoRT programme on their creative thinking. Fifty-three students participated in the research; 27 participated in a CoRT programme, while 26 did not participate in such programme. The ANCOVA test showed that the students who participated in the CoRT programme outperformed significantly, in creative thinking, the students who did not. Moreover, the students in the CoRT programme whose achievement scores were between 86 and 100 outperformed significantly the other achievement groups of students. Furthermore, students with reported high ability outperformed significantly the other ability groups of students. The results did not show statistically significant differences in students’ creativity attributed to gender.
Transverse vibrations of shear-deformable beams using a general higher order theory
Kosmatka, J. B.
1993-01-01
A general higher order theory is developed to study the static and vibrational behavior of beam structures having an arbitrary cross section that utilizes both out-of-plane shear-dependent warping and in-plane (anticlastic) deformations. The equations of motion are derived via Hamilton's principle, where the full 3D constitutive relations are used. A simplified version of the general higher-order theory is also presented for beams having an arbitrary cross section that includes out-of-plane shear deformation but assumes that stresses within the cross section and in-plane deformations are negligible. This simplified model, which is accurate for long to moderately short wavelengths, offers substantial improvements over existing higher order theories that are limited to beams with thin rectangular cross sections. The current approach will be very useful in the study of thin-wall closed-cell beams such as airfoil-type sections where the magnitude of shear-related cross-sectional warping is significant.
Compositional modeling of three-phase flow with gravity using higher-order finite element methods
Moortgat, Joachim
2011-05-11
A wide range of applications in subsurface flow involve water, a nonaqueous phase liquid (NAPL) or oil, and a gas phase, such as air or CO2. The numerical simulation of such processes is computationally challenging and requires accurate compositional modeling of three-phase flow in porous media. In this work, we simulate for the first time three-phase compositional flow using higher-order finite element methods. Gravity poses complications in modeling multiphase processes because it drives countercurrent flow among phases. To resolve this issue, we propose a new method for the upwinding of three-phase mobilities. Numerical examples, related to enhanced oil recovery and carbon sequestration, are presented to illustrate the capabilities of the proposed algorithm. We pay special attention to challenges associated with gravitational instabilities and take into account compressibility and various phase behavior effects, including swelling, viscosity changes, and vaporization. We find that the proposed higher-order method can capture sharp solution discontinuities, yielding accurate predictions of phase boundaries arising in computational three-phase flow. This work sets the stage for a broad extension of the higher-order methods for numerical simulation of three-phase flow for complex geometries and processes.
Rehmat, Abeera Parvaiz
As we progress into the 21st century, higher-order thinking skills and achievement in science and math are essential to meet the educational requirement of STEM careers. Educators need to think of innovative ways to engage and prepare students for current and future challenges while cultivating an interest among students in STEM disciplines. An instructional pedagogy that can capture students' attention, support interdisciplinary STEM practices, and foster higher-order thinking skills is problem-based learning. Problem-based learning embedded in the social constructivist view of teaching and learning (Savery & Duffy, 1995) promotes self-regulated learning that is enhanced through exploration, cooperative social activity, and discourse (Fosnot, 1996). This quasi-experimental mixed methods study was conducted with 98 fourth grade students. The study utilized STEM content assessments, a standardized critical thinking test, STEM attitude survey, PBL questionnaire, and field notes from classroom observations to investigate the impact of problem-based learning on students' content knowledge, critical thinking, and their attitude towards STEM. Subsequently, it explored students' experiences of STEM integration in a PBL environment. The quantitative results revealed a significant difference between groups in regards to their content knowledge, critical thinking skills, and STEM attitude. From the qualitative results, three themes emerged: learning approaches, increased interaction, and design and engineering implementation. From the overall data set, students described the PBL environment to be highly interactive that prompted them to employ multiple approaches, including design and engineering to solve the problem.
Higher Order, Hybrid BEM/FEM Methods Applied to Antenna Modeling
Fink, P. W.; Wilton, D. R.; Dobbins, J. A.
2002-01-01
In this presentation, the authors address topics relevant to higher order modeling using hybrid BEM/FEM formulations. The first of these is the limitation on convergence rates imposed by geometric modeling errors in the analysis of scattering by a dielectric sphere. The second topic is the application of an Incomplete LU Threshold (ILUT) preconditioner to solve the linear system resulting from the BEM/FEM formulation. The final tOpic is the application of the higher order BEM/FEM formulation to antenna modeling problems. The authors have previously presented work on the benefits of higher order modeling. To achieve these benefits, special attention is required in the integration of singular and near-singular terms arising in the surface integral equation. Several methods for handling these terms have been presented. It is also well known that achieving he high rates of convergence afforded by higher order bases may als'o require the employment of higher order geometry models. A number of publications have described the use of quadratic elements to model curved surfaces. The authors have shown in an EFIE formulation, applied to scattering by a PEC .sphere, that quadratic order elements may be insufficient to prevent the domination of modeling errors. In fact, on a PEC sphere with radius r = 0.58 Lambda(sub 0), a quartic order geometry representation was required to obtain a convergence benefi.t from quadratic bases when compared to the convergence rate achieved with linear bases. Initial trials indicate that, for a dielectric sphere of the same radius, - requirements on the geometry model are not as severe as for the PEC sphere. The authors will present convergence results for higher order bases as a function of the geometry model order in the hybrid BEM/FEM formulation applied to dielectric spheres. It is well known that the system matrix resulting from the hybrid BEM/FEM formulation is ill -conditioned. For many real applications, a good preconditioner is required
Shukla, Divya; Dungsungnoen, Aj Pattaradanai
2016-01-01
Higher order thinking skills (HOTS) has portrayed immense industry demand and the major goal of educational institution in imparting education is to inculcate higher order thinking skills. This compiles and mandate the institutions and instructor to develop the higher order thinking skills among students in order to prepare them for effective…
Directory of Open Access Journals (Sweden)
Bagheri
2015-09-01
Full Text Available Background Several factors have been reported as risk factors for multiple sclerosis (MS; however, the main causes of the disease are still unknown. A geographical area with a low MS incidence is Ahvaz, Iran. Objectives The objective of this study was to evaluate the association of several demographic characteristics, family history, and birth month with MS in Ahvaz. Patients and Methods This was a case-control study including 155 MS cases and 155 controls matched for age, sex, and residential status. The participants were selected randomly, using a systematic method, from the MS patients referred to the MS Society of Khuzestan (Iran. The data collection tool was a standardized questionnaire designed by the authors to assess demographic characteristics. Data were analyzed using descriptive statistics including mean, frequency, and standard deviation and inferential statistical tests including χ2, Fisher’s exact test, and logistic regression using SPSS version 19. Results In both cases and controls, no significant associations were found between Arab ethnicity and incidence of MS, marital status and risk of MS in Ahvaz, or more than 15-year residency in Ahvaz, birth in Khuzestan, and month of birth and the risk of MS (P > 0.05. However, there was a marginally significant association between living from birth to age 15 years in Ahvaz and MS (P = 0.05. Furthermore, there was an association between a family history of MS and the risk of MS in Ahvaz (P = 0.02, which was significant in univariate logistic regression (P = 0.006. Conclusions The findings suggested that according to the ecological conditions of Ahvaz, a family history of MS may increase the risk of developing MS.
SHARP: A Spatially Higher-order, Relativistic Particle-in-cell Code
Energy Technology Data Exchange (ETDEWEB)
Shalaby, Mohamad; Broderick, Avery E. [Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1 (Canada); Chang, Philip [Department of Physics, University of Wisconsin-Milwaukee, 1900 E. Kenwood Boulevard, Milwaukee, WI 53211 (United States); Pfrommer, Christoph [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Lamberts, Astrid [Theoretical Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Puchwein, Ewald, E-mail: mshalaby@live.ca [Institute of Astronomy and Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom)
2017-05-20
Numerical heating in particle-in-cell (PIC) codes currently precludes the accurate simulation of cold, relativistic plasma over long periods, severely limiting their applications in astrophysical environments. We present a spatially higher-order accurate relativistic PIC algorithm in one spatial dimension, which conserves charge and momentum exactly. We utilize the smoothness implied by the usage of higher-order interpolation functions to achieve a spatially higher-order accurate algorithm (up to the fifth order). We validate our algorithm against several test problems—thermal stability of stationary plasma, stability of linear plasma waves, and two-stream instability in the relativistic and non-relativistic regimes. Comparing our simulations to exact solutions of the dispersion relations, we demonstrate that SHARP can quantitatively reproduce important kinetic features of the linear regime. Our simulations have a superior ability to control energy non-conservation and avoid numerical heating in comparison to common second-order schemes. We provide a natural definition for convergence of a general PIC algorithm: the complement of physical modes captured by the simulation, i.e., those that lie above the Poisson noise, must grow commensurately with the resolution. This implies that it is necessary to simultaneously increase the number of particles per cell and decrease the cell size. We demonstrate that traditional ways for testing for convergence fail, leading to plateauing of the energy error. This new PIC code enables us to faithfully study the long-term evolution of plasma problems that require absolute control of the energy and momentum conservation.
The detection of higher-order acoustic transitions is reflected in the N1 ERP.
Weise, Annekathrin; Schröger, Erich; Horváth, János
2018-01-30
The auditory system features various types of dedicated change detectors enabling the rapid parsing of auditory stimulation into distinct events. The activity of such detectors is reflected by the N1 ERP. Interestingly, certain acoustic transitions show an asymmetric N1 elicitation pattern: whereas first-order transitions (e.g., a change from a segment of constant frequency to a frequency glide [c-to-g change]) elicit N1, higher-order transitions (e.g., glide-to-constant [g-to-c] changes) do not. Consensus attributes this asymmetry to the absence of any available sensory mechanism that is able to rapidly detect higher-order changes. In contrast, our study provides compelling evidence for such a mechanism. We collected electrophysiological and behavioral data in a transient-detection paradigm. In each condition, a random (50%-50%) sequence of two types of tones occurred, which did or did not contain a transition (e.g., c-to-g and constant stimuli or g-to-c and glide tones). Additionally, the rate of pitch change of the glide varied (i.e., 10 vs. 40 semitones per second) in order to increase the number of responding neural assemblies. The rate manipulation modulated transient ERPs and behavioral detection performance for g-to-c transitions much stronger than for c-to-g transitions. The topographic and tomographic analyses suggest that the N1 response to c-to-g and also to g-to-c transitions emerged from the superior temporal gyrus. This strongly supports a sensory mechanism that allows the fast detection of higher-order changes. © 2018 Society for Psychophysiological Research.
Simon, Nicole A.
Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory experience, linking with educational technologies (Pyatt & Sims, 2007; 2011; Trundle & Bell, 2010). A causal-comparative quantitative study was conducted with 150 learners enrolled at a two-year community college, to determine the effects of simulation laboratory experiments on Higher-Order Learning, Critical Thinking Skills, and Cognitive Load. The treatment population used simulated experiments, while the non-treatment sections performed traditional expository experiments. A comparison was made using the Revised Two-Factor Study Process survey, Motivated Strategies for Learning Questionnaire, and the Scientific Attitude Inventory survey, using a Repeated Measures ANOVA test for treatment or non-treatment. A main effect of simulated laboratory experiments was found for both Higher-Order Learning, [F (1, 148) = 30.32,p = 0.00, eta2 = 0.12] and Critical Thinking Skills, [F (1, 148) = 14.64,p = 0.00, eta 2 = 0.17] such that simulations showed greater increases than traditional experiments. Post-lab treatment group self-reports indicated increased marginal means (+4.86) in Higher-Order Learning and Critical Thinking Skills, compared to the non-treatment group (+4.71). Simulations also improved the scientific skills and mastery of basic scientific subject matter. It is recommended that additional research recognize that learners' Critical Thinking Skills change due to different instructional methodologies that occur throughout a semester.
Higher Order Modes HOM___s in Coupled Cavities of the Flash Module ACC39
Energy Technology Data Exchange (ETDEWEB)
Shinton, I.R.R.; /Manchester U. /Cockcroft Inst. Accel. Sci. Tech.; Jones, R.M.; /Manchester U. /DESY; Li, Z.; /SLAC; Zhang, P.; /Manchester U. /Cockcroft Inst. Accel. Sci. Tech. /DESY
2012-09-14
We analyse the higher order modes (HOM's) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations (GSM) are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.
Slat Noise Predictions Using Higher-Order Finite-Difference Methods on Overset Grids
Housman, Jeffrey A.; Kiris, Cetin
2016-01-01
Computational aeroacoustic simulations using the structured overset grid approach and higher-order finite difference methods within the Launch Ascent and Vehicle Aerodynamics (LAVA) solver framework are presented for slat noise predictions. The simulations are part of a collaborative study comparing noise generation mechanisms between a conventional slat and a Krueger leading edge flap. Simulation results are compared with experimental data acquired during an aeroacoustic test in the NASA Langley Quiet Flow Facility. Details of the structured overset grid, numerical discretization, and turbulence model are provided.
On higher-order boundary conditions at elastic-plastic boundaries in strain-gradient plasticity
DEFF Research Database (Denmark)
Niordson, Christian Frithiof
2008-01-01
are suppressed by using a very high artificial hardening modulus. Through numerical studies of pure bending under plane strain conditions, it is shown that this method predicts the build-up of higher order stresses in the pseudo-elastic regime. This has the effect of delaying the onset of incipient yield......, as well as extending the plastic zone further toward the neutral axis of the beam, when compared to conventional models. Arguments supporting the present method are presented that rest on both mathematical and physical grounds. The results obtained are compared with other methods for dealing with higher...
Higher-order processes in x-ray photoionization of atoms
International Nuclear Information System (INIS)
Kanter, E. P.; Dunford, R. W.; Krassig, B.; Southworth, S. H.; Young, L.
2006-01-01
There are several fourth-generation X-ray light source projects now underway around the world and it is anticipated that by the end of the decade, one or more of these X-ray free-electron lasers will be operational. In this contribution, we describe recent measurements and future plans to study both multielectron and multiphoton atomic photoionization. Although such higher-order processes are rare with present third-generation sources, they will be commonplace in experimental work with the new sources. The topics we discuss here are double K-shell ionization and two-photon X-ray photoionization
Electrodynamic characterisitcs measurements of higher order modes in S-band cavity
Donetsky, R.; Lalayan, M.; Sobenin, N. P.; Orlov, A.; Bulygin, A.
2017-12-01
The 800 MHz superconducting cavities with grooved beam pipes were suggested as one of the harmonic cavities design options for High Luminosity LHC project. Cavity simulations were carried out and scaled aluminium prototype having operational mode frequency of 2400 MHz was manufactured for testing the results of simulations. The experimental measurements of transverse shunt impedance with error estimation for higher order modes TM 110 and TE 111 for S-band elliptical cavity were done. The experiments using dielectric and metallic spherical beads and with ring probe were carried out. The Q-factor measurements for two-cell structure and array of two cells were carried out.
Higher Order Mode (HOM) Impedance and Damping Study for the LHC Capture Cavity
Linnecar, Trevor Paul R; Tückmantel, Joachim; CERN. Geneva. SPS and LHC Division
2001-01-01
To investigate the higher order mode, HOM, damping in the LHC 200MHz ACN cavity when using four HOM couplers, simulations have been done by both 3-D frequency domain and time domain methods. These simulations have previously been used in other studies of HOM damped cavities and shown to be effective by comparing measurement and simulation results[1] [2]. Using these methods the impedance spectrum of the HOM modes in the cavity before and after damping has been obtained. From this, detailed information about the HOM coupler's contribution to HOM damping can be obtained. The distribution and magnitude of some potentially dangerous HOM modes in the ACN cavity have been found.
HIGHER ORDER SPECIATION EFFECTS ON PLUTONIUM L3 X-RAY ABSORPTION NEAR EDGE SPECTRA.
Energy Technology Data Exchange (ETDEWEB)
Conradson, Steven D.; Abney, Kent D.; Begg, Bruce D.; Brady, Erik D.; Clark, David L.; den Auwer, Christophe; Ding, Mei; Dorhout, Peter K.; Espinosa-Faller, Francisco J.; Gordon, Pamela L.; Hess, Nancy J.; Hess, Ryan F.; Keogh, D. Webster; Lander, Gerard H.; Lupinetti, Anthony J.; Neu, Mary P.; Palmer, Phillip D.; Paviet-Hartmann, Patricia; Reilly, Sean D.; Runde, Wolfgang H.; Tait, C. Drew; Veirs, D. Kirk
2003-06-09
Pu L{sub 3} X-ray Near Edge Absorption Spectra for Pu(0-VII) are reported for more than 50 chalcogenides, chlorides, hydrates, hydroxides, nitrates, carbonates, oxy-hydroxides, and other compounds both as solids and in solution, and substituted in zirconlite, perovksite, and borosilicate glass. This large data base extends the known correlations between the energy and shape of these spectra from the usual association of the XANES with valence and site symmetry to higher order chemical effects. Because of the large number of compounds of these different types a number of novel and unexpected behaviors are observed.
A higher-order-mode fiber delivery for Ti:Sapphire femtosecond lasers
DEFF Research Database (Denmark)
Jespersen, Kim Giessmann; Le, Tuan; Grüner-Nielsen, Lars Erik
2010-01-01
We report the first higher-order-mode fiber with anomalous dispersion at 800nm and demonstrate its potential in femtosecond pulse delivery for Ti:Sapphire femtosecond lasers. We obtain 125fs pulses after propagating a distance of 3.6 meters in solid-silica fiber. The pulses could be further...... compressed in a quartz rod to nearly chirp-free 110fs pulses. Femtosecond pulse delivery is achieved by launching the laser output directly into the delivery fiber without any pre-chirping of the input pulse. The demonstrated pulse delivery scheme suggests scaling to >20meters for pulse delivery in harsh...
Visibility-Based Hypothesis Testing Using Higher-Order Optical Interference
Jachura, Michał; Jarzyna, Marcin; Lipka, Michał; Wasilewski, Wojciech; Banaszek, Konrad
2018-03-01
Many quantum information protocols rely on optical interference to compare data sets with efficiency or security unattainable by classical means. Standard implementations exploit first-order coherence between signals whose preparation requires a shared phase reference. Here, we analyze and experimentally demonstrate the binary discrimination of visibility hypotheses based on higher-order interference for optical signals with a random relative phase. This provides a robust protocol implementation primitive when a phase lock is unavailable or impractical. With the primitive cost quantified by the total detected optical energy, optimal operation is typically reached in the few-photon regime.
Experimental generation and application of the superposition of higher-order Bessel beams
CSIR Research Space (South Africa)
Dudley, Angela L
2009-07-01
Full Text Available Academy of Sciences of Belarus 4 School of Physics, University of Stellenbosch Presented at the 2009 South African Institute of Physics Annual Conference University of KwaZulu-Natal Durban, South Africa 6-10 July 2009 Page 2 © CSIR 2008... www.csir.co.za Generation of Bessel Fields: • METHOD 1: Ring Slit Aperture • METHOD 2: Axicon Adaptation of method 1 to produce superpositions of higher-order Bessel beams: J. Durnin, J.J. Miceli and J.H. Eberly, Phys. Rev. Lett. 58 1499...
Exploring evidence of higher order thinking skills in the writing of first year undergraduates
Directory of Open Access Journals (Sweden)
Lynette Faragher
2014-08-01
Full Text Available Research indicates that concern is often expressed about the language and discourse skills new students bring with them when they first enrol at university, which leads to assumptions being made about their academic abilities. In this paper, an argument is developed through detailed analysis of student writing, that many new first year students have nascent Higher Order Thinking Skills and the potential to be successful in their studies. The work of Robert Marzano and his associates (Marzano, 2001; Marzano & Kendall, 2007, 2008 is applied to student writing.
Higher order constraints on the Higgs production rate from fixed-target DIS data
International Nuclear Information System (INIS)
Alekhin, S.; Bluemlein, J.; Moch, S.
2011-01-01
The constraints of fixed-target DIS data in fits of parton distributions including QCD corrections to next-to-next-to leading order are studied. We point out a potential problem in the analysis of the NMC data which can lead to inconsistencies in the extracted value for α s (M Z ) and the gluon distribution at higher orders in QCD. The implications for predictions of rates for Standard Model Higgs boson production at hadron colliders are investigated. We conclude that the current range of excluded Higgs boson masses at the Tevatron appears to be much too large. (orig.)
Nonlinear optics in the LP(02) higher-order mode of a fiber.
Chen, Y; Chen, Z; Wadsworth, W J; Birks, T A
2013-07-29
The distinct disperion properties of higher-order modes in optical fibers permit the nonlinear generation of radiation deeper into the ultraviolet than is possible with the fundamental mode. This is exploited using adiabatic, broadband mode convertors to couple light efficiently from an input fundamental mode and also to return the generated light to an output fundamental mode over a broad spectral range. For example, we generate visible and UV supercontinuum light in the LP(02) mode of a photonic crystal fiber from sub-ns pulses with a wavelength of 532 nm.
Fractional equivalent Lagrangian densities for a fractional higher-order equation
International Nuclear Information System (INIS)
Fujioka, J
2014-01-01
In this communication we show that the equivalent Lagrangian densities (ELDs) of a fractional higher-order nonlinear Schrödinger equation with stable soliton-like solutions can be related in a hitherto unknown way. This new relationship is described in terms of a new fractional operator that includes both left- and right-sided fractional derivatives. Using this operator it is possible to generate new ELDs that contain different fractional parts, in addition to the already known ELDs, which only differ by a sum of first-order partial derivatives of two arbitrary functions. (fast track communications)
Higher-Order-Mode Diagnostics and Suppression in Superconducting Cavities (HOMSC12)
Jones, Roger M.
2014-01-01
From the 25th of June through Wednesday lunchtime of the 27th of June 2012 the Cockcroft Institute and ASTeC hosted an ICFA supported mini workshop on Higher-Order-Mode Diagnostics and Suppression in Superconducting Cavities (HOMSC12). The local organizing committee for this international workshop was chaired by S. Buckley (ASTeC/STFC), conference administration by S. Waller (ASTeC/STFC), and the scientific program committee by R.M. Jones (Cockcroft Institute/University of Manchester).
On the regularity of mild solutions to complete higher order differential equations on Banach spaces
Directory of Open Access Journals (Sweden)
Nezam Iraniparast
2015-09-01
Full Text Available For the complete higher order differential equation u(n(t=Σk=0n-1Aku(k(t+f(t, t∈ R (* on a Banach space E, we give a new definition of mild solutions of (*. We then characterize the regular admissibility of a translation invariant subspace al M of BUC(R, E with respect to (* in terms of solvability of the operator equation Σj=0n-1AjXal Dj-Xal Dn = C. As application, almost periodicity of mild solutions of (* is proved.
Higher-order anisotropies in the blast-wave model: Disentangling flow and density field anisotropies
Energy Technology Data Exchange (ETDEWEB)
Cimerman, Jakub [Czech Technical University in Prague, FNSPE, Prague (Czech Republic); Comenius University, FMPI, Bratislava (Slovakia); Tomasik, Boris [Czech Technical University in Prague, FNSPE, Prague (Czech Republic); Univerzita Mateja Bela, FPV, Banska Bystrica (Slovakia); Csanad, Mate; Loekoes, Sandor [Eoetvoes Lorand University, Budapest (Hungary)
2017-08-15
We formulate a generalisation of the blast-wave model which is suitable for the description of higher-order azimuthal anisotropies of the hadron production. The model includes anisotropy in the density profile as well as an anisotropy in the transverse expansion velocity field. We then study how these two kinds of anisotropies influence the single-particle distributions and the correlation radii of two-particle correlation functions. Particularly we focus on the third-order anisotropy and consideration is given averaging over different orientations of the event plane. (orig.)
HOM [higher order mode] losses at the IR [interaction region] of the B-factory
International Nuclear Information System (INIS)
Heifets, S.
1990-08-01
Masking at the interaction region (IR) will presumably reduce the synchrotron radiation background in the detector. One possible layout of the IR for B-factory shows a rather complicated system of masks. A bunch passing each mask will generate RF waves. These waves (called usually higher order modes, HOM-s) will be absorbed in the beam pipe wall producing additional heating and, interacting with the beam, kicking particles in the radial and azimuthal directions. This may change the bunch motion and its emittance. These effects are estimated in the present note
Exotic quantum holonomy and higher-order exceptional points in quantum kicked tops.
Tanaka, Atushi; Kim, Sang Wook; Cheon, Taksu
2014-04-01
The correspondence between exotic quantum holonomy, which occurs in families of Hermitian cycles, and exceptional points (EPs) for non-Hermitian quantum theory is examined in quantum kicked tops. Under a suitable condition, an explicit expression of the adiabatic parameter dependencies of quasienergies and stationary states, which exhibit anholonomies, is obtained. It is also shown that the quantum kicked tops with the complexified adiabatic parameter have a higher-order EP, which is broken into lower-order EPs with the application of small perturbations. The stability of exotic holonomy against such bifurcation is demonstrated.
Topology optimized design of a transverse electric higher order mode converter
DEFF Research Database (Denmark)
Frellsen, Louise Floor; Ding, Yunhong; Sigmund, Ole
2016-01-01
The investigation of methods to support the ever increasing demand for data transfer has continued for years; one such method suggested within the field of optical communication, is space division multiplexing (SDM) [1]. Simultaneously the field of photonic integrated circuits (PICs) is being...... present the possibility of employing topology optimization (TO) to design a device that allows for reversible conversion between the transverse electric fundamental even (TE0) mode and the second higher order odd mode (TE2). Topology optimization is an iterative inverse design process, where repeated...
A higher-order nonlinear Schrödinger equation with variable coefficients
Carvajal, X.; Linares, F.
2003-01-01
We study the initial value problem (IVP) associated to a higher-order nonlinear Schrödinger equation with variable coefficients. Under some regularity on its coefficients we establish local well-posedness for the IVP for data in $H^s(\\mathbb R)$, $s\\ge1/4$, improving previous results [22]. The main ingredient in our proof is an estimate of the maximal function associated to the linear solution similar to the sharp one obtained for linear solutions of the Schrödinger and K...
Liu, Qun; Jiang, Daqing
2018-04-01
In this paper, two stochastic predator-prey models with general functional response and higher-order perturbation are proposed and investigated. For the nonautonomous periodic case of the system, by using Khasminskii's theory of periodic solution, we show that the system admits a nontrivial positive T-periodic solution. For the system disturbed by both white and telegraph noises, sufficient conditions for positive recurrence and the existence of an ergodic stationary distribution to the solutions are established. The existence of stationary distribution implies stochastic weak stability to some extent.
Higher-order Bessel like beams with z-dependent cone angles
CSIR Research Space (South Africa)
Ismail, Y
2010-08-01
Full Text Available .64.81.22. Terms of Use: http://spiedl.org/terms Fig.5: Optical design to generate z-dependent Bessel-like beams 4. CONSIDERING A MATHEMATICAL APPROACH TO EXPLAINING Z-DEPENDENT BLB?S The stationary phase method is implemented in order to confirm... on higher-order z-dependent BLB?s [6]. 5. EXPERIMENTALLY GENERATED Z-DEPENDENT BESSEL-LIKE BEAMS From the above in can be deduced that these beams are Bessel-like hence they are so named z-dependent Bessel-like beams. These beams are produced however...
On Delay-Independent Criteria for Oscillation of Higher-Order Functional Differential Equations
Directory of Open Access Journals (Sweden)
Yuangong Sun
2011-01-01
Full Text Available We investigate the oscillation of the following higher-order functional differential equation: x(n(t+q(t|x(t-τ|λ-1x(t-τ=e(t, where q(t and e(t are continuous functions on [t0,∞, 1>λ>0 and τ≠0 are constants. Unlike most of delay-dependent oscillation results in the literature, two delay-independent oscillation criteria for the equation are established in both the case τ>0 and the case τ<0 under the assumption that the potentials q(t and e(t change signs on [t0,∞.
Power-law scaling of extreme dynamics near higher-order exceptional points
Zhong, Q.; Christodoulides, D. N.; Khajavikhan, M.; Makris, K. G.; El-Ganainy, R.
2018-02-01
We investigate the extreme dynamics of non-Hermitian systems near higher-order exceptional points in photonic networks constructed using the bosonic algebra method. We show that strong power oscillations for certain initial conditions can occur as a result of the peculiar eigenspace geometry and its dimensionality collapse near these singularities. By using complementary numerical and analytical approaches, we show that, in the parity-time (PT ) phase near exceptional points, the logarithm of the maximum optical power amplification scales linearly with the order of the exceptional point. We focus in our discussion on photonic systems, but we note that our results apply to other physical systems as well.
Directory of Open Access Journals (Sweden)
J. Aizpurua
2011-09-01
Full Text Available The sensitivity in surface enhanced infrared spectroscopy (SEIRS strongly depends on where the resonant excitation is spectrally located compared to the molecular vibration that is to be enhanced. In this contribution, we study the effect of coupling in the electromagnetic properties of 2D gold nanorod arrays in the IR. We also study the SEIRS activity of higher order resonant excitations in long nanoantennas to identify polaritonic signals of a supporting SiO2 layer with nanometer thickness (3 nm on a silicon substrate.
Higher order mode damping studies on the PEP-II B-Factory RF cavity
International Nuclear Information System (INIS)
Rimmer, R.; Goldberg, D.; Lambertson, G.; Voelker, F.; Ko, K.; Kroll, N.; Pendleton, R.; Schwarz, H.; Adams, F.; De Jong, M.
1992-03-01
We describe studies of the higher-order-mode (HOM) properties of the prototype 476 MHz RF cavity for the proposed PEP-II B-Factory and a waveguide damping scheme to reduce possible HOM-driven coupled-bunch beam instability growth. Numerical studies include modelling of the HOM spectrum using MAFIA and ARGUS, and calculation of the loaded Q's of the damped modes using data from these codes and the Kroll-Yu method. We discuss briefly the experimental investigations of the modes, which will be made in a full-size low-power test cavity, using probes, wire excitation and bead perturbation methods
Electron bunch train excited higher-order modes in a superconducting RF cavity
Gao, Yong-Feng; Huang, Sen-Lin; Wang, Fang; Feng, Li-Wen; Zhuang, De-Hao; Lin, Lin; Zhu, Feng; Hao, Jian-Kui; Quan, Sheng-Wen; Liu, Ke-Xin
2017-04-01
Higher-order mode (HOM) based intra-cavity beam diagnostics has been proved effective and convenient in superconducting radio-frequency (SRF) accelerators. Our recent research shows that the beam harmonics in the bunch train excited HOM spectrum, which have much higher signal-to-noise ratio than the intrinsic HOM peaks, may also be useful for beam diagnostics. In this paper, we will present our study on bunch train excited HOMs, including a theoretical model and recent experiments carried out based on the DC-SRF photoinjector and SRF linac at Peking University. Supported by National Natural Science Foundation of China (11275014)
Analysis of Higher Order Modes in Large Superconducting Radio Frequency Accelerating Structures
Galek, Tomasz; Brackebusch, Korinna; Van Rienen, Ursula
2015-01-01
Superconducting radio frequency cavities used for accelerating charged particle beams are commonly used in accelerator facilities around the world. The design and optimization of modern superconducting RF cavities requires intensive numerical simulations. Vast number of operational parameters must be calculated to ensure appropriate functioning of the accelerating structures. In this study, we primarily focus on estimation and behavior of higher order modes in superconducting RF cavities connected in chains. To calculate large RF models the state-space concatenation scheme, an efficient hybrid method, is employed.
Experimental investigations of higher-order springing and whipping-WILS project
Directory of Open Access Journals (Sweden)
Hong Sa Young
2014-12-01
Full Text Available Springing and whipping are becoming increasingly important considerations in ship design as container ships increase in size. In this study, the springing and whipping characteristics of a large container ship were investigated through a series of systematic model tests in waves. A multi-segmented hull model with a backbone was adopted for measurement of springing and whipping signals. A conversion method for extracting torsion springing and whipping is described in this paper for the case of an open-section backbone. Higher-order springing, higher-mode torsion responses, and the effects of linear and nonlinear springing in irregular waves are highlighted in the discussion.
Higher order thinking skills: using e-portfolio in project-based learning
Lukitasari, M.; Handhika, J.; Murtafiah, W.
2018-03-01
The purpose of this research is to describe students' higher-order thinking skills through project-based learning using e-portfolio. The method used in this research is descriptive qualitative method. The research instruments used were test, unstructured interview, and documentation. Research subjects were students of mathematics, physics and biology education department who take the Basics Physics course. The result shows that through project-based learning using e-portfolio the students’ ability to: analyze (medium category, N-Gain 0.67), evaluate (medium category, N-Gain 0.51), and create (medium Category, N-Gain 0.44) are improved.
Equivalence of two formalisms for calculating higher order synchrotron sideband spin resonances
International Nuclear Information System (INIS)
Mane, S.R.
1988-01-01
Synchrotron sideband resonances of a first order spin resonance are generally regarded as the most important higher order spin resonances in a high-energy storage ring. Yokoya's formula for these resonances is rederived, including some extra terms, which he neglected, but which turn out to be of comparable magnitude to the terms retained. Including these terms, Yokoya's formalism and the SMILE algorithm are shown to be equivalent to leading order in the resonance strengths. The theoretical calculations are shown to agree with certain measurements from SPEAR
Higher Order Modes HOM's in Coupled Cavities of the Flash Module ACC39
International Nuclear Information System (INIS)
Shinton, I.R.R.
2012-01-01
We analyse the higher order modes (HOM's) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations (GSM) are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.
Higher order modes HOMs in coupled cavities of the FLASH module ACC39
Shinton, I R R; Li, Z; Zhang, P
2011-01-01
We analyse the higher order modes (HOM’s) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations (GSM) are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.
Rani, Monika; Bhatti, Harbax S.; Singh, Vikramjeet
2017-11-01
In optical communication, the behavior of the ultrashort pulses of optical solitons can be described through nonlinear Schrodinger equation. This partial differential equation is widely used to contemplate a number of physically important phenomena, including optical shock waves, laser and plasma physics, quantum mechanics, elastic media, etc. The exact analytical solution of (1+n)-dimensional higher order nonlinear Schrodinger equation by He's variational iteration method has been presented. Our proposed solutions are very helpful in studying the solitary wave phenomena and ensure rapid convergent series and avoid round off errors. Different examples with graphical representations have been given to justify the capability of the method.
Ren, Fengli; Cao, Jinde
2007-03-01
In this paper, several sufficient conditions are obtained ensuring existence, global attractivity and global asymptotic stability of the periodic solution for the higher-order bidirectional associative memory neural networks with periodic coefficients and delays by using the continuation theorem of Mawhin's coincidence degree theory, the Lyapunov functional and the non-singular M-matrix. Two examples are exploited to illustrate the effectiveness of the proposed criteria. These results are more effective than the ones in the literature for some neural networks, and can be applied to the design of globally attractive or globally asymptotically stable networks and thus have important significance in both theory and applications.
Higher-order chromatin structure in DSB induction, repair and misrepair
Czech Academy of Sciences Publication Activity Database
Falk, Martin; Lukášová, Emilie; Kozubek, Stanislav
2010-01-01
Roč. 704, 1-3 (2010), s. 88-100 ISSN 1383-5742 R&D Projects: GA MŠk ME 919; GA AV ČR(CZ) IAA500040802; GA AV ČR(CZ) 1QS500040508 Grant - others:GA MŠk(CZ) LC535 Program:LC Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : DNA double strand breaks * DSB repair * higher-order chromatin structure Subject RIV: BO - Biophysics Impact factor: 8.741, year: 2010
Higher-order radiative corrections for b b ¯→H-W+
Kidonakis, Nikolaos
2018-02-01
I present higher-order radiative corrections from collinear and soft-gluon emission for the associated production of a charged Higgs boson with a W boson. The calculation uses expressions from resummation at next-to-leading-logarithm accuracy. From the resummed cross section I derive analytical formulas at approximate next-to-next-to-leading order and next-to-next-to-next-to-leading order. Total cross sections are presented for the process b b ¯→H-W+ at various LHC energies. The transverse momentum and rapidity distributions of the charged Higgs boson are also calculated.
Critical and Higher Order Thinking in Online Threaded Discussions in the Slovak Context
Directory of Open Access Journals (Sweden)
Katarina Pisutova-Gerber
2009-02-01
Full Text Available This article describes and analyzes efforts to use collaborative asynchronous discussion forums in a three semester online education program for NGO leaders and managers in Slovakia. Slovakia, as a country with autocratic styles of teacher-centered education, presents strong barriers to the implementation of collaborative learning activities. The authors used Garrison’s four stage cognitive processing categories to analyze some of the online discussions in the program. The two higher order critical thinking categories – integration and solution – appeared in student discussions only when prompted by specific instructional techniques.
Higher-order schemes for the Laplace transformation method for parabolic problems
Douglas, C.
2011-01-01
In this paper we solve linear parabolic problems using the three stage noble algorithms. First, the time discretization is approximated using the Laplace transformation method, which is both parallel in time (and can be in space, too) and extremely high order convergent. Second, higher-order compact schemes of order four and six are used for the the spatial discretization. Finally, the discretized linear algebraic systems are solved using multigrid to show the actual convergence rate for numerical examples, which are compared to other numerical solution methods. © 2011 Springer-Verlag.
Adaptive grouping for the higher-order multilevel fast multipole method
DEFF Research Database (Denmark)
Borries, Oscar Peter; Jørgensen, Erik; Meincke, Peter
2014-01-01
An alternative parameter-free adaptive approach for the grouping of the basis function patterns in the multilevel fast multipole method is presented, yielding significant memory savings compared to the traditional Octree grouping for most discretizations, particularly when using higher-order basis...... functions. Results from both a uniformly and nonuniformly meshed scatterer are presented, showing how the technique is worthwhile even for regular meshes, and demonstrating that there is no loss of accuracy in spite of the large reduction in memory requirements and the relatively low computational cost....
Controlled higher-order transverse mode conversion from a fiber laser by polarization manipulation
Huang, Bin; Yi, Qian; Yang, Lingling; Zhao, Chujun; Wen, Shuangchun
2018-02-01
We report a vectorial fiber laser with controlled transverse mode conversion by intra-cavity polarization manipulation. By combining a q-plate and two quarter-wave plates (QWPs), we can generate a switchable polarization state output represented by the higher-order Poincaré sphere (l = +1, l = -1), and distinguish the fourfold degenerate LP11 mode. The four transverse vector modes can be obtained and switched in a flexible way, and the slope efficiency of the fiber laser can reach up to 39.4%. This compactness, high efficiency, and switchable operation potential will benefit a range of applications, such as materials processing, particle manipulation, etc.
Higher Order Corrections in the CoLoRFulNNLO Framework
Somogyi, G.; Kardos, A.; Szőr, Z.; Trócsányi, Z.
We discuss the CoLoRFulNNLO method for computing higher order radiative corrections to jet cross sections in perturbative QCD. We apply our method to the calculation of event shapes and jet rates in three-jet production in electron-positron annihilation. We validate our code by comparing our predictions to previous results in the literature and present the jet cone energy fraction distribution at NNLO accuracy. We also present preliminary NNLO results for the three-jet rate using the Durham jet clustering algorithm matched to resummed predictions at NLL accuracy, and a comparison to LEP data.
Effect of impedance and higher order chromaticity on the measurement of linear chromaticity
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V. H. Ranjbar
2011-08-01
Full Text Available The combined effect of impedance and higher order chromaticity can act on the beam in a nontrivial manner which can cause a tune shift which depends on the relative momenta with respect to the “on momentum” particle (Δp/p. Experimentally, this tune shift affects the measurement of the linear chromaticity which is traditionally measured with a change of Δp/p. The theory behind this effect will be derived in this paper. Computer simulations and experimental data from the Tevatron will be used to support the theory.
Effect of impedance and higher order chromaticity on the measurement of linear chromaticity
V. H. Ranjbar; C. Y. Tan
2011-01-01
The combined effect of impedance and higher order chromaticity can act on the beam in a nontrivial manner which can cause a tune shift which depends on the relative momenta with respect to the “on momentum” particle (Δp/p). Experimentally, this tune shift affects the measurement of the linear chromaticity which is traditionally measured with a change of Δp/p. The theory behind this effect will be derived in this paper. Computer simulations and experimental data from the Tevatron will be used ...
Directory of Open Access Journals (Sweden)
Nurhayati Nurhayati
2017-12-01
Full Text Available Abstract This study aims to describe the ability of higher order thinking students in solving the problem of the concept of optics after given the learning with problem-based learning model. This research uses a descriptive method with quantitative approach. The subjects of the research are students of the second semester of physics education study program, amounting to 19 people. Data collection techniques used are two tier multiple choice shaped test consisting of eight questions include the level of analyzing, evaluating and creating. Based on the results of data analysis, it is known that the ability of high-level thinking of students in optical learning has enough categories with the following details: (1 The percentage of students who have excellent high-level thinking skills is 15.79%, good category of 31.58%, enough category of 42.11%, and category less than 10.53%; (2 The percentage of student ability in answer about level of analyze equal to 68.42%, student ability in answer about evaluation level 57.89% and equal to 53.51% for student ability in answer level question create. Keywords: higher order thinking, optics, problem-based learning model Abstrak Penelitian ini bertujuan untuk mendeskripsikan kemampuan berpikir tingkat tinggi mahasiswa (higher order thinking dalam menyelesaikan soal konsep optika setelah diberikan pembelajaran dengan model problem based learning. Metode penelitian yang digunakan adalah metode deskriptif dengan pendekatan kuantitatif. Subjek penelitian yaitu mahasiswa semester II program studi pendidikan fisika yang berjumlah 19 orang. Teknik pengumpulan data yang digunakan adalah tes berbentuk two tier multiple choice yang terdiri dari delapan soal meliputi tingkatan menganalisis, mengevaluasi dan mencipta. Berdasarkan hasil analisis data, diketahui bahwa kemampuan berpikir tingkat tinggi mahasiswa dalam pembelajaran optika memiliki kategori cukup dengan rincian sebagai berikut: (1 Persentase mahasiswa yang
In-service teacher education: asking questions for higher order thinking in visual literacy
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Visvaganthie Moodley
2013-01-01
Full Text Available The kinds of questions teachers ask may thwart or promote learner high-order thinking; teachers themselves must have expertise in questioning skills to promote higher order cognition among learners. Drawing on experiential knowledge of assessment, and as an English-teaching professional development programme (PDP facilitator, I demonstrate that within the framework of a carefully structured subject-specific PDP, teachers can be taught how to enhance thinking skills in the English visual literacy (VL learning classroom. Guided by an earlier taxonomy of cognition, and using qualitative methodology, the paper analyses data obtained from: (i observation notes and examination equivalents of 40 teachers from various public schools in Gauteng who were engaged in the Advanced Certificate in Education (ACE, English specialization programme; and (ii a case study of three teachers by means of semi-structured interviews, and a study of their lesson plans and worksheets.The paper examines, specifically, teachers' choice of texts and questions asked, for English second-language learners for the teaching of VL. It concludes by suggesting that if teachers themselves are first engaged in the cognitive processes they wish learners to acquire, they are better positioned to promote higher order among their learners.
Higher-order topological insulators and superconductors protected by inversion symmetry
Khalaf, Eslam
2018-05-01
We study surface states of topological crystalline insulators and superconductors protected by inversion symmetry. These fall into the category of "higher-order" topological insulators and superconductors which possess surface states that propagate along one-dimensional curves (hinges) or are localized at some points (corners) on the surface. We provide a complete classification of inversion-protected higher-order topological insulators and superconductors in any spatial dimension for the 10 symmetry classes by means of a layer construction. We discuss possible physical realizations of such states starting with a time-reversal-invariant topological insulator (class AII) in three dimensions or a time-reversal-invariant topological superconductor (class DIII) in two or three dimensions. The former exhibits one-dimensional chiral or helical modes propagating along opposite edges, whereas the latter hosts Majorana zero modes localized to two opposite corners. Being protected by inversion, such states are not pinned to a specific pair of edges or corners, thus offering the possibility of controlling their location by applying inversion-symmetric perturbations such as magnetic field.
A higher-order tensor vessel tractography for segmentation of vascular structures.
Cetin, Suheyla; Unal, Gozde
2015-10-01
A new vascular structure segmentation method, which is based on a cylindrical flux-based higher order tensor (HOT), is presented. On a vessel structure, the HOT naturally models branching points, which create challenges for vessel segmentation algorithms. In a general linear HOT model embedded in 3D, one has to work with an even order tensor due to an enforced antipodal-symmetry on the unit sphere. However, in scenarios such as in a bifurcation, the antipodally-symmetric tensor embedded in 3D will not be useful. In order to overcome that limitation, we embed the tensor in 4D and obtain a structure that can model asymmetric junction scenarios. During construction of a higher order tensor (e.g. third or fourth order) in 4D, the orientation vectors lie on the unit 3-sphere, in contrast to the unit 2-sphere in 3D tensor modeling. This 4D tensor is exploited in a seed-based vessel segmentation algorithm, where the principal directions of the 4D HOT is obtained by decomposition, and used in a HOT tractography approach. We demonstrate quantitative validation of the proposed algorithm on both synthetic complex tubular structures as well as real cerebral vasculature in Magnetic Resonance Angiography (MRA) datasets and coronary arteries from Computed Tomography Angiography (CTA) volumes.
International Nuclear Information System (INIS)
Khan, K.A.
2001-01-01
Experimental studies related to a thin isotropic steel beam are presented. The beam was harmonically excited along its axis creating a situation of parametric excitation. A possible two-to-one internal resonance was considered between the third and fourth modes of the beam with an external resonance of its fourth mode. The coupling phenomenon responsible for transfer of energy from high frequency modes to a widely spaced low frequency mode was studied by using conventional tools and higher-order spectra (third-order spectrum (bispectrum) and fourth-order spectrum (trispectrum)). Pointwise dimensions of the attractors were examined to ascertain their chaotic character. The potential of higher-order spectra in detecting the quadratic and cubic phase couplings among the participating modes during bifurcations, periodically modulated motions, and chaotically modulated motions was also examined. The experimental results are provided in the form of power spectra, fractal dimensions, bispectra, bicoherence spectra, and trispectrum. Experimental observations of transitions from periodic to periodically modulated to chaotically-modulated motions are also presented. (author)
Common themes and cell type specific variations of higher order chromatin arrangements in the mouse
Directory of Open Access Journals (Sweden)
Cremer Thomas
2005-12-01
Full Text Available Abstract Background Similarities as well as differences in higher order chromatin arrangements of human cell types were previously reported. For an evolutionary comparison, we now studied the arrangements of chromosome territories and centromere regions in six mouse cell types (lymphocytes, embryonic stem cells, macrophages, fibroblasts, myoblasts and myotubes with fluorescence in situ hybridization and confocal laser scanning microscopy. Both species evolved pronounced differences in karyotypes after their last common ancestors lived about 87 million years ago and thus seem particularly suited to elucidate common and cell type specific themes of higher order chromatin arrangements in mammals. Results All mouse cell types showed non-random correlations of radial chromosome territory positions with gene density as well as with chromosome size. The distribution of chromosome territories and pericentromeric heterochromatin changed during differentiation, leading to distinct cell type specific distribution patterns. We exclude a strict dependence of these differences on nuclear shape. Positional differences in mouse cell nuclei were less pronounced compared to human cell nuclei in agreement with smaller differences in chromosome size and gene density. Notably, the position of chromosome territories relative to each other was very variable. Conclusion Chromosome territory arrangements according to chromosome size and gene density provide common, evolutionary conserved themes in both, human and mouse cell types. Our findings are incompatible with a previously reported model of parental genome separation.
Higher-order Multivariable Polynomial Regression to Estimate Human Affective States
Wei, Jie; Chen, Tong; Liu, Guangyuan; Yang, Jiemin
2016-03-01
From direct observations, facial, vocal, gestural, physiological, and central nervous signals, estimating human affective states through computational models such as multivariate linear-regression analysis, support vector regression, and artificial neural network, have been proposed in the past decade. In these models, linear models are generally lack of precision because of ignoring intrinsic nonlinearities of complex psychophysiological processes; and nonlinear models commonly adopt complicated algorithms. To improve accuracy and simplify model, we introduce a new computational modeling method named as higher-order multivariable polynomial regression to estimate human affective states. The study employs standardized pictures in the International Affective Picture System to induce thirty subjects’ affective states, and obtains pure affective patterns of skin conductance as input variables to the higher-order multivariable polynomial model for predicting affective valence and arousal. Experimental results show that our method is able to obtain efficient correlation coefficients of 0.98 and 0.96 for estimation of affective valence and arousal, respectively. Moreover, the method may provide certain indirect evidences that valence and arousal have their brain’s motivational circuit origins. Thus, the proposed method can serve as a novel one for efficiently estimating human affective states.
Higher order thinking skills competencies required by outcomes-based education from learners
Directory of Open Access Journals (Sweden)
MM Chabeli
2006-09-01
Full Text Available Outcomes-Based Education (OBE brought about a significant paradigm shift in the education and training of learners in South Africa. OBE requires a shift from focusing on the teacher input (instruction offerings or syllabuses expressed in terms of content, to focusing on learner outcomes. OBE is moving away from ‘transmission’ models to constructivistic, learner-centered models that put emphasis on learning as an active process (Nieburh, 1996:30. Teachers act as facilitators and mediators of learning (Norms and Standards, Government Gazette vol 415, no 20844 of 2000. Facilitators are responsible to create the environment that is conducive for learners to construct their own knowledge, skills and values through interaction (Peters, 2000. The first critical cross-field outcome accepted by the South African Qualification Framework (SAQA is that learners should be able to identify and solve problems by using critical and creative thinking skills. This paper seeks to explore some higher order thinking skills competencies required by OBE from learners such as critical thinking, reflective thinking, creative thinking, dialogic / dialectic thinking, decision making, problem solving and emotional intelligence and their implications in facilitating teaching and learning from the theoretical perspective. The philosophical underpinning of these higher order thinking skills is described to give direction to the study. It is recommended that a study focusing on the assessment of these intellectual concepts be made. The study may be qualitative, quantitative or mixed methods in nature (Creswell 2005.
Higher order thinking skills competencies required by outcomes-based education from learners.
Chabeli, M M
2006-08-01
Outcomes-Based Education (OBE) brought about a significant paradigm shift in the education and training of learners in South Africa. OBE requires a shift from focusing on the teacher input (instruction offerings or syllabuses expressed in terms of content), to focusing on learner outcomes. OBE is moving away from 'transmission' models to constructivistic, learner-centered models that put emphasis on learning as an active process (Nieburh, 1996:30). Teachers act as facilitators and mediators of learning (Norms and Standards, Government Gazette vol 415, no 20844 of 2000). Facilitators are responsible to create the environment that is conducive for learners to construct their own knowledge, skills and values through interaction (Peters, 2000). The first critical cross-field outcome accepted by the South African Qualification Framework (SAQA) is that learners should be able to identify and solve problems by using critical and creative thinking skills. This paper seeks to explore some higher order thinking skills competencies required by OBE from learners such as critical thinking, reflective thinking, creative thinking, dialogic / dialectic thinking, decision making, problem solving and emotional intelligence and their implications in facilitating teaching and learning from the theoretical perspective. The philosophical underpinning of these higher order thinking skills is described to give direction to the study. It is recommended that a study focusing on the assessment of these intellectual concepts be made. The study may be qualitative, quantitative or mixed methods in nature (Creswell 2005).
International Nuclear Information System (INIS)
Kropaczek, D.J.; Turinsky, P.J.
1990-01-01
Perturbation techniques utilized in reactor analysis have recently been applied in the solution of the in-core nuclear fuel management optimization problem. The use of such methods is motivated by the need to evaluate many times over, the core physics characteristics of loading pattern solutions obtained through an optimization process, which is typically iterative. Perturbation theory provides an efficient alternative to the prohibitively expensive, repetitive solutions of the system few-group neutron diffusion equations required in solving the fuel placement problem. A primary concern in the use of such methods is the control of perturbation errors arising during the fuel shuffling process. First-order accurate models inevitably resort to undue restriction of fuel movement during the optimization process to control these errors. Higher order perturbation theory models have the potential to overcome such limitations, which may result in the identification of local versus global optima. An accurate, computationally efficient reactor physics model based on higher order perturbation theory and geared toward the needs of large-scale in-core fuel management optimization is presented in this paper
Higher-order ice-sheet modelling accelerated by multigrid on graphics cards
Brædstrup, Christian; Egholm, David
2013-04-01
Higher-order ice flow modelling is a very computer intensive process owing primarily to the nonlinear influence of the horizontal stress coupling. When applied for simulating long-term glacial landscape evolution, the ice-sheet models must consider very long time series, while both high temporal and spatial resolution is needed to resolve small effects. The use of higher-order and full stokes models have therefore seen very limited usage in this field. However, recent advances in graphics card (GPU) technology for high performance computing have proven extremely efficient in accelerating many large-scale scientific computations. The general purpose GPU (GPGPU) technology is cheap, has a low power consumption and fits into a normal desktop computer. It could therefore provide a powerful tool for many glaciologists working on ice flow models. Our current research focuses on utilising the GPU as a tool in ice-sheet and glacier modelling. To this extent we have implemented the Integrated Second-Order Shallow Ice Approximation (iSOSIA) equations on the device using the finite difference method. To accelerate the computations, the GPU solver uses a non-linear Red-Black Gauss-Seidel iterator coupled with a Full Approximation Scheme (FAS) multigrid setup to further aid convergence. The GPU finite difference implementation provides the inherent parallelization that scales from hundreds to several thousands of cores on newer cards. We demonstrate the efficiency of the GPU multigrid solver using benchmark experiments.
Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping
Directory of Open Access Journals (Sweden)
Skrollan Stockinger
2013-09-01
Full Text Available A new approach for the investigation of a higher-order reaction by on-column reaction gas chromatography is presented. The reaction and the analytical separation are combined in a single experiment to investigate the Diels–Alder reaction of benzenediazonium-2-carboxylate as a benzyne precursor with various anthracene derivatives, i.e. anthracene, 9-bromoanthracene, 9-anthracenecarboxaldehyde and 9-anthracenemethanol. To overcome limitations of short reaction contact times at elevated temperatures a novel experimental setup was developed involving a cooling trap to achieve focusing and mixing of the reactants at a defined spot in a fused-silica capillary. This trap functions as a reactor within the separation column in the oven of a gas chromatograph. The reactants are sequentially injected to avoid undefined mixing in the injection port. An experimental protocol was developed with optimized injection intervals and cooling times to achieve sufficient conversions at short reaction times. Reaction products were rapidly identified by mass spectrometric detection. This new approach represents a practical procedure to investigate higher-order reactions at an analytical level and it simultaneously provides valuable information for the optimization of the reaction conditions.
International Nuclear Information System (INIS)
Sutheerawatthana, Pitch; Minato, Takayuki
2010-01-01
The response of a social group is a missing element in the formal impact assessment model. Previous discussion of the involvement of social groups in an intervention has mainly focused on the formation of the intervention. This article discusses the involvement of social groups in a different way. A descriptive model is proposed by incorporating a social group's response into the concept of second- and higher-order effects. The model is developed based on a cause-effect relationship through the observation of phenomena in case studies. The model clarifies the process by which social groups interact with a lower-order effect and then generate a higher-order effect in an iterative manner. This study classifies social groups' responses into three forms-opposing, modifying, and advantage-taking action-and places them in six pathways. The model is expected to be used as an analytical tool for investigating and identifying impacts in the planning stage and as a framework for monitoring social groups' responses during the implementation stage of a policy, plan, program, or project (PPPPs).
Jaber, Nizar
2016-01-06
© 2016 IOP Publishing Ltd. In this study, we demonstrate analytically and experimentally the excitations of the higher order modes of vibrations in electrostatically actuated clamped-clamped microbeam resonators. The concept is based on using partial electrodes with shapes that induce strong excitation of the mode of interest. The devices are fabricated using polyimide as a structural layer coated with nickel from the top and chrome and gold layers from the bottom. Experimentally, frequency sweeps with different electro-dynamical loading conditions are shown to demonstrate the excitation of the higher order modes of vibration. Using a half electrode, the second mode is excited with high amplitude of vibration compared with almost zero response using the full electrode. Also, using a two-third electrode configuration is shown to amplify the third mode resonance amplitude compared with the full electrode under the same electrical loading conditions. An analytical model is developed based on the Euler-Bernollui beam model and the Galerkin method to simulate the device response. Good agreement between the simulation results and the experimental data is reported.
A higher order space-time Galerkin scheme for time domain integral equations
Pray, Andrew J.
2014-12-01
Stability of time domain integral equation (TDIE) solvers has remained an elusive goal formany years. Advancement of this research has largely progressed on four fronts: 1) Exact integration, 2) Lubich quadrature, 3) smooth temporal basis functions, and 4) space-time separation of convolutions with the retarded potential. The latter method\\'s efficacy in stabilizing solutions to the time domain electric field integral equation (TD-EFIE) was previously reported for first-order surface descriptions (flat elements) and zeroth-order functions as the temporal basis. In this work, we develop the methodology necessary to extend the scheme to higher order surface descriptions as well as to enable its use with higher order basis functions in both space and time. These basis functions are then used in a space-time Galerkin framework. A number of results are presented that demonstrate convergence in time. The viability of the space-time separation method in producing stable results is demonstrated experimentally for these examples.
Study of higher order modes in superconducting accelerating structures for linac applications
Energy Technology Data Exchange (ETDEWEB)
Schuh, Marcel
2011-06-22
Higher Order Modes (HOMs) can severely limit the operation of superconducting cavities in a linear accelerator with high beam current, high duty factor and complex pulse structure. Therefore, the full HOM spectrum has to be analysed in detail to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam dynamics simulation code, Simulation of higher order Mode Dynamics (SMD), focusing on beam-HOM interaction, has been developed in the frame of this project. SMD allows to analyse the beam behaviour under the presence of HOMs, taking into account many important effects, such as for example the HOM frequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. SMD is used to investigate in detail into the effects of HOMs in the Superconducting Proton Linac (SPL) at CERN and in particular their potential to drive beam instabilities in the longitudinal and transverse direction. Based on these results, HOM damping requirements for the HOM coupler design are then defined. In addition, the linear accelerators of the European Spallation Source (ESS) and the Spallation Neutron Source (SNS) are analysed with respect to HOM impact and the results are compared with the SPL simulations. (orig.)
Spatio-chromatic adaptation via higher-order canonical correlation analysis of natural images.
Gutmann, Michael U; Laparra, Valero; Hyvärinen, Aapo; Malo, Jesús
2014-01-01
Independent component and canonical correlation analysis are two general-purpose statistical methods with wide applicability. In neuroscience, independent component analysis of chromatic natural images explains the spatio-chromatic structure of primary cortical receptive fields in terms of properties of the visual environment. Canonical correlation analysis explains similarly chromatic adaptation to different illuminations. But, as we show in this paper, neither of the two methods generalizes well to explain both spatio-chromatic processing and adaptation at the same time. We propose a statistical method which combines the desirable properties of independent component and canonical correlation analysis: It finds independent components in each data set which, across the two data sets, are related to each other via linear or higher-order correlations. The new method is as widely applicable as canonical correlation analysis, and also to more than two data sets. We call it higher-order canonical correlation analysis. When applied to chromatic natural images, we found that it provides a single (unified) statistical framework which accounts for both spatio-chromatic processing and adaptation. Filters with spatio-chromatic tuning properties as in the primary visual cortex emerged and corresponding-colors psychophysics was reproduced reasonably well. We used the new method to make a theory-driven testable prediction on how the neural response to colored patterns should change when the illumination changes. We predict shifts in the responses which are comparable to the shifts reported for chromatic contrast habituation.
A novel nature inspired firefly algorithm with higher order neural network: Performance analysis
Directory of Open Access Journals (Sweden)
Janmenjoy Nayak
2016-03-01
Full Text Available The applications of both Feed Forward Neural network and Multilayer perceptron are very diverse and saturated. But the linear threshold unit of feed forward networks causes fast learning with limited capabilities, while due to multilayering, the back propagation of errors exhibits slow training speed in MLP. So, a higher order network can be constructed by correlating between the input variables to perform nonlinear mapping using the single layer of input units for overcoming the above drawbacks. In this paper, a Firefly based higher order neural network has been proposed for data classification for maintaining fast learning and avoids the exponential increase of processing units. A vast literature survey has been conducted to review the state of the art of the previous developed models. The performance of the proposed method has been tested with various benchmark datasets from UCI machine learning repository and compared with the performance of other established models. Experimental results imply that the proposed method is fast, steady, reliable and provides better classification accuracy than others.
International Nuclear Information System (INIS)
Gandini, A.
1996-01-01
The heuristically based generalized perturbation theory (HGPT), to first and higher order, applied to the neutron field of a reactor system, is discussed in relation to the criticality reset procedure. This procedure is implicit within the GPT methodology, corresponding to the so called filtering of the importance function relevant to the neutron field from the fundamental mode contamination. It is common practice to use the so called ''lambda''-mode filter. In order to account for any possible reset option, a general definition is introduced of an intensive control variable (ρ) entering into the governing equations, and correspondingly a fundamental ρ-mode filtering of the importance function is defined, relevant to the real criticality reset (control) mechanism adopted. A simple example illustrates the need to take into account the correct filtering, so as to avoid significant inaccuracies in the sensitivity calculation results. The extension of this filtering technique to other functions entering into the GPT perturbative formulations at first and higher order is also discussed. (author)
On the Entropy Based Associative Memory Model with Higher-Order Correlations
Directory of Open Access Journals (Sweden)
Masahiro Nakagawa
2010-01-01
Full Text Available In this paper, an entropy based associative memory model will be proposed and applied to memory retrievals with an orthogonal learning model so as to compare with the conventional model based on the quadratic Lyapunov functional to be minimized during the retrieval process. In the present approach, the updating dynamics will be constructed on the basis of the entropy minimization strategy which may be reduced asymptotically to the above-mentioned conventional dynamics as a special case ignoring the higher-order correlations. According to the introduction of the entropy functional, one may involve higer-order correlation effects between neurons in a self-contained manner without any heuristic coupling coefficients as in the conventional manner. In fact we shall show such higher order coupling tensors are to be uniquely determined in the framework of the entropy based approach. From numerical results, it will be found that the presently proposed novel approach realizes much larger memory capacity than that of the quadratic Lyapunov functional approach, e.g., associatron.
Calculating Higher-Order Moments of Phylogenetic Stochastic Mapping Summaries in Linear Time
Dhar, Amrit
2017-01-01
Abstract Stochastic mapping is a simulation-based method for probabilistically mapping substitution histories onto phylogenies according to continuous-time Markov models of evolution. This technique can be used to infer properties of the evolutionary process on the phylogeny and, unlike parsimony-based mapping, conditions on the observed data to randomly draw substitution mappings that do not necessarily require the minimum number of events on a tree. Most stochastic mapping applications simulate substitution mappings only to estimate the mean and/or variance of two commonly used mapping summaries: the number of particular types of substitutions (labeled substitution counts) and the time spent in a particular group of states (labeled dwelling times) on the tree. Fast, simulation-free algorithms for calculating the mean of stochastic mapping summaries exist. Importantly, these algorithms scale linearly in the number of tips/leaves of the phylogenetic tree. However, to our knowledge, no such algorithm exists for calculating higher-order moments of stochastic mapping summaries. We present one such simulation-free dynamic programming algorithm that calculates prior and posterior mapping variances and scales linearly in the number of phylogeny tips. Our procedure suggests a general framework that can be used to efficiently compute higher-order moments of stochastic mapping summaries without simulations. We demonstrate the usefulness of our algorithm by extending previously developed statistical tests for rate variation across sites and for detecting evolutionarily conserved regions in genomic sequences. PMID:28177780
International Nuclear Information System (INIS)
Jha, D.K.; Kant, Tarun; Srinivas, K.; Singh, R.K.
2013-01-01
Highlights: • We model through-thickness variation of material properties in functionally graded (FG) plates. • Effect of material grading index on deformations, stresses and natural frequency of FG plates is studied. • Effect of higher order terms in displacement models is studied for plate statics. • The benchmark solutions for the static analysis and free vibration of thick FG plates are presented. -- Abstract: Functionally graded materials (FGMs) are the potential candidates under consideration for designing the first wall of fusion reactors with a view to make best use of potential properties of available materials under severe thermo-mechanical loading conditions. A higher order shear and normal deformations plate theory is employed for stress and free vibration analyses of functionally graded (FG) elastic, rectangular, and simply (diaphragm) supported plates. Although FGMs are highly heterogeneous in nature, they are generally idealized as continua with mechanical properties changing smoothly with respect to spatial coordinates. The material properties of FG plates are assumed here to vary through thickness of plate in a continuous manner. Young's modulii and material densities are considered to be varying continuously in thickness direction according to volume fraction of constituents which are mathematically modeled here as exponential and power law functions. The effects of variation of material properties in terms of material gradation index on deformations, stresses and natural frequency of FG plates are investigated. The accuracy of present numerical solutions has been established with respect to exact three-dimensional (3D) elasticity solutions and the other models’ solutions available in literature
Influence of squeeze film damping on the higher-order modes of clamped–clamped microbeams
Alcheikh, Nouha
2016-05-06
This paper presents an experimental study and a finite-element analysis of the effect of squeeze film damping on the resonance frequency and quality factor of the higher-order flexure vibrations modes of clamped-clamped microbeams. Viscoelastic and silicon nitride microbeams are fabricated and are electrostatically actuated by various electrode configurations to trigger the first, second, and third modes. The damping characteristic and the resonance frequency of these modes are examined for a wide range of gas pressure and electrostatic voltage loads. The results of the silicon nitride beams and viscoelastic beams are compared. It is found that the intrinsic material loss is the major dissipation mechanism at low pressure for the viscoelastic microbeams, significantly limiting their quality factor. It is also found that while the silicon nitride beams show higher quality factors at the intrinsic and molecular regimes of pressure, due to their low intrinsic loss, their quality factors near atmospheric pressure are lower than those of the viscoelastic microbeams. Further, the higher-order modes of all the beams show much higher quality factors at atmospheric pressure compared to the first mode, which could be promising for operating such resonators in air. Experimental results and finite element model simulations show good agreement for resonance frequency and quality factor for the three studied modes. © 2016 IOP Publishing Ltd.
A practical implementation of the higher-order transverse-integrated nodal diffusion method
International Nuclear Information System (INIS)
Prinsloo, Rian H.; Tomašević, Djordje I.; Moraal, Harm
2014-01-01
Highlights: • A practical higher-order nodal method is developed for diffusion calculations. • The method resolves the issue of the transverse leakage approximation. • The method achieves much superior accuracy as compared to standard nodal methods. • The calculational cost is only about 50% greater than standard nodal methods. • The method is packaged in a module for connection to existing nodal codes. - Abstract: Transverse-integrated nodal diffusion methods currently represent the standard in full core neutronic simulation. The primary shortcoming of this approach is the utilization of the quadratic transverse leakage approximation. This approach, although proven to work well for typical LWR problems, is not consistent with the formulation of nodal methods and can cause accuracy and convergence problems. In this work, an improved, consistent quadratic leakage approximation is formulated, which derives from the class of higher-order nodal methods developed some years ago. Further, a number of iteration schemes are developed around this consistent quadratic leakage approximation which yields accurate node average results in much improved calculational times. The most promising of these iteration schemes results from utilizing the consistent leakage approximation as a correction method to the standard quadratic leakage approximation. Numerical results are demonstrated on a set of benchmark problems and further applied to a realistic reactor problem, particularly the SAFARI-1 reactor, operating at Necsa, South Africa. The final optimal solution strategy is packaged into a standalone module which may simply be coupled to existing nodal diffusion codes
Multipacting and higher order mode analysis of 325 MHz single spoke resonators
International Nuclear Information System (INIS)
Pal, Mukesh Kumar; Gaur, Rahul; Kumar, Vinit
2015-01-01
Superconducting Single Spoke Resonators (SSRs) will be used to accelerate the H - ions from 3 MeV to 160 MeV in the injector linac for the proposed Indian Spallation Neutron Source (ISNS) at RRCAT. Electromagnetic design studies of 325 MHz SSRs have been performed for βg = 0.11, 0.22 and 0.42. Performance of SSRs are typically limited by multipacting phenomenon and higher order modes. In our design, we have performed detailed studies of electron multipacting phenomenon, which is a resonant process, using a computer code CST-PS. Based on this analysis, refinements in the geometry of the SSRs have been made, in order to reduce the growth rate of multipacting. We have also carried out extensive analysis of Higher Order Mode (HOM) for the SSR structure, using the computer code CST-MWS, where the R/Q parameter has been calculated for monopole, dipole and quadrupole HaMs. Details of these calculations will be presented in this paper. (author)
Hotspot detection using image pattern recognition based on higher-order local auto-correlation
Maeda, Shimon; Matsunawa, Tetsuaki; Ogawa, Ryuji; Ichikawa, Hirotaka; Takahata, Kazuhiro; Miyairi, Masahiro; Kotani, Toshiya; Nojima, Shigeki; Tanaka, Satoshi; Nakagawa, Kei; Saito, Tamaki; Mimotogi, Shoji; Inoue, Soichi; Nosato, Hirokazu; Sakanashi, Hidenori; Kobayashi, Takumi; Murakawa, Masahiro; Higuchi, Tetsuya; Takahashi, Eiichi; Otsu, Nobuyuki
2011-04-01
Below 40nm design node, systematic variation due to lithography must be taken into consideration during the early stage of design. So far, litho-aware design using lithography simulation models has been widely applied to assure that designs are printed on silicon without any error. However, the lithography simulation approach is very time consuming, and under time-to-market pressure, repetitive redesign by this approach may result in the missing of the market window. This paper proposes a fast hotspot detection support method by flexible and intelligent vision system image pattern recognition based on Higher-Order Local Autocorrelation. Our method learns the geometrical properties of the given design data without any defects as normal patterns, and automatically detects the design patterns with hotspots from the test data as abnormal patterns. The Higher-Order Local Autocorrelation method can extract features from the graphic image of design pattern, and computational cost of the extraction is constant regardless of the number of design pattern polygons. This approach can reduce turnaround time (TAT) dramatically only on 1CPU, compared with the conventional simulation-based approach, and by distributed processing, this has proven to deliver linear scalability with each additional CPU.
Higher order coupling between rigid-body and elastic motion in flexible mechanisms
International Nuclear Information System (INIS)
Esat, I.I.; Ianakiev, A.
1995-01-01
The paper presents an investigation of the influence of the higher order coupling terms between the rigid-body and elastic motion into flexible mechanism dynamics. The configuration of the mechanical system is obtained by using the so called hybrid coordinates. The kinematic description of the mechanism was obtained using the D-H 4 x 4 transformation matrices. The elastic deformation of each point of the mechanism is described by the finite element modeling (FEM) type interpolation scheme. The dynamic model of the flexible mechanism consists due to the hybrid coordinates of two groups of differential equations. The first group describes the manipulator transport motion and the second group describes the vibration. In this paper the authors evaluated the contribution of the coupling terms between the two groups of differential equations and selected only those with high contribution
A comparison of different methods to implement higher order derivatives of density functionals
Energy Technology Data Exchange (ETDEWEB)
van Dam, Hubertus J.J. [Brookhaven National Lab. (BNL), Upton, NY (United States)
2016-05-18
Density functional theory is the dominant approach in electronic structure methods today. To calculate properties higher order derivatives of the density functionals are required. These derivatives might be implemented manually,by automatic differentiation, or by symbolic algebra programs. Different authors have cited different reasons for using the particular method of their choice. This paper presents work where all three approaches were used and the strengths and weaknesses of each approach are considered. It is found that all three methods produce code that is suffficiently performanted for practical applications, despite the fact that our symbolic algebra generated code and our automatic differentiation code still have scope for significant optimization. The automatic differentiation approach is the best option for producing readable and maintainable code.
Phase-plane analysis to an “anisotropic” higher-order traffic flow model
Wu, Chun-Xiu
2018-04-01
The qualitative theory of differential equations is applied to investigate the traveling wave solution to an “anisotropic” higher-order viscous traffic flow model under the Lagrange coordinate system. The types and stabilities of the equilibrium points are discussed in the phase plane. Through the numerical simulation, the overall distribution structures of trajectories are drawn to analyze the relation between the phase diagram and the selected conservative solution variables, and the influences of the parameters on the system are studied. The limit-circle, limit circle-spiral point, saddle-spiral point and saddle-nodal point solutions are obtained. These steady-state solutions provide good explanation for the phenomena of the oscillatory and homogeneous congestions in real-world traffic.
Higher-order Solution of Stochastic Diffusion equation with Nonlinear Losses Using WHEP technique
El-Beltagy, Mohamed A.; Al-Mulla, Noah
2014-01-01
Using Wiener-Hermite expansion with perturbation (WHEP) technique in the solution of the stochastic partial differential equations (SPDEs) has the advantage of converting the problem to a system of deterministic equations that can be solved efficiently using the standard deterministic numerical methods [1]. The Wiener-Hermite expansion is the only known expansion that handles the white/colored noise exactly. The main statistics, such as the mean, covariance, and higher order statistical moments, can be calculated by simple formulae involving only the deterministic Wiener-Hermite coefficients. In this poster, the WHEP technique is used to solve the 2D diffusion equation with nonlinear losses and excited with white noise. The solution will be obtained numerically and will be validated and compared with the analytical solution that can be obtained from any symbolic mathematics package such as Mathematica.
Relativistic stars in degenerate higher-order scalar-tensor theories after GW170817
Kobayashi, Tsutomu; Hiramatsu, Takashi
2018-05-01
We study relativistic stars in degenerate higher-order scalar-tensor theories that evade the constraint on the speed of gravitational waves imposed by GW170817. It is shown that the exterior metric is given by the usual Schwarzschild solution if the lower order Horndeski terms are ignored in the Lagrangian and a shift symmetry is assumed. However, this class of theories exhibits partial breaking of Vainshtein screening in the stellar interior and thus modifies the structure of a star. Employing a simple concrete model, we show that for high-density stars the mass-radius relation is altered significantly even if the parameters are chosen so that only a tiny correction is expected in the Newtonian regime. We also find that, depending on the parameters, there is a maximum central density above which solutions cease to exist.