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Sample records for higher order human

  1. Human motion perception: Higher-order organization

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K.; Proffitt, Dennis R.

    1990-01-01

    An overview is given of higher-order motion perception and organization. It is argued that motion is sufficient to fully specify a number of environmental properties, including: depth order, three-dimensional form, object displacement, and dynamics. A grammar of motion perception is proposed; applications of this work for display design are discussed.

  2. Higher-order Genome Organization in Human Disease

    PubMed Central

    Misteli, Tom

    2010-01-01

    Genomes are organized into complex higher-order structures by folding of the DNA into chromatin fibers, chromosome domains, and ultimately chromosomes. The higher-order organization of genomes is functionally important for gene regulation and control of gene expression programs. Defects in how chromatin is globally organized are relevant for physiological and pathological processes. Mutations and transcriptional misregulation of several global genome organizers are linked to human diseases and global alterations in chromatin structure are emerging as key players in maintenance of genome stability, aging, and the formation of cancer translocations. PMID:20591991

  3. Dichotomous Identification Keys: A Ladder to Higher Order Knowledge about the Human Body

    ERIC Educational Resources Information Center

    Sorgo, Andrej

    2006-01-01

    We tried to enrich teaching human anatomy in high school biology lessons. Students construct dichotomous identification keys to the cells, tissues, organs, or body parts. By doing this, students have achieved higher-order cognitive levels of knowledge because construction of such keys is based on analysis, synthesis, and evaluation. Students found…

  4. Higher-order Multivariable Polynomial Regression to Estimate Human Affective States

    PubMed Central

    Wei, Jie; Chen, Tong; Liu, Guangyuan; Yang, Jiemin

    2016-01-01

    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. PMID:26996254

  5. Higher-order Multivariable Polynomial Regression to Estimate Human Affective States.

    PubMed

    Wei, Jie; Chen, Tong; Liu, Guangyuan; Yang, Jiemin

    2016-01-01

    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. PMID:26996254

  6. Higher-order Multivariable Polynomial Regression to Estimate Human Affective States

    NASA Astrophysics Data System (ADS)

    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.

  7. Measuring higher order optical aberrations of the human eye: techniques and applications.

    PubMed

    Carvalho, L Alberto V; Castro, J C; Carvalho, L Antonio V

    2002-11-01

    In the present paper we discuss the development of "wave-front", an instrument for determining the lower and higher optical aberrations of the human eye. We also discuss the advantages that such instrumentation and techniques might bring to the ophthalmology professional of the 21st century. By shining a small light spot on the retina of subjects and observing the light that is reflected back from within the eye, we are able to quantitatively determine the amount of lower order aberrations (astigmatism, myopia, hyperopia) and higher order aberrations (coma, spherical aberration, etc.). We have measured artificial eyes with calibrated ametropia ranging from +5 to -5 D, with and without 2 D astigmatism with axis at 45 degrees and 90 degrees. We used a device known as the Hartmann-Shack (HS) sensor, originally developed for measuring the optical aberrations of optical instruments and general refracting surfaces in astronomical telescopes. The HS sensor sends information to a computer software for decomposition of wave-front aberrations into a set of Zernike polynomials. These polynomials have special mathematical properties and are more suitable in this case than the traditional Seidel polynomials. We have demonstrated that this technique is more precise than conventional autorefraction, with a root mean square error (RMSE) of less than 0.1 micro m for a 4-mm diameter pupil. In terms of dioptric power this represents an RMSE error of less than 0.04 D and 5 degrees for the axis. This precision is sufficient for customized corneal ablations, among other applications. PMID:12426641

  8. Adaptive Optics Analysis of Visual Benefit with Higher-order Aberrations Correction of Human Eye - Poster Paper

    NASA Astrophysics Data System (ADS)

    Xue, Lixia; Dai, Yun; Rao, Xuejun; Wang, Cheng; Hu, Yiyun; Liu, Qian; Jiang, Wenhan

    2008-01-01

    Higher-order aberrations correction can improve visual performance of human eye to some extent. To evaluate how much visual benefit can be obtained with higher-order aberrations correction we developed an adaptive optics vision simulator (AOVS). Dynamic real time optimized modal compensation was used to implement various customized higher-order ocular aberrations correction strategies. The experimental results indicate that higher-order aberrations correction can improve visual performance of human eye comparing with only lower-order aberration correction but the improvement degree and higher-order aberration correction strategy are different from each individual. Some subjects can acquire great visual benefit when higher-order aberrations were corrected but some subjects acquire little visual benefit even though all higher-order aberrations were corrected. Therefore, relative to general lower-order aberrations correction strategy, customized higher-order aberrations correction strategy is needed to obtain optimal visual improvement for each individual. AOVS provides an effective tool for higher-order ocular aberrations optometry for customized ocular aberrations correction.

  9. Modulation of Higher-Order Olfaction Components on Executive Functions in Humans

    PubMed Central

    Fagundo, Ana B.; Jiménez-Murcia, Susana; Giner-Bartolomé, Cristina; Islam, Mohammed Anisul; de la Torre, Rafael; Pastor, Antoni; Casanueva, Felipe F.; Crujeiras, Ana B.; Granero, Roser; Baños, Rosa; Botella, Cristina; Fernández-Real, Jose M.; Frühbeck, Gema; Gómez-Ambrosi, Javier; Menchón, José M.; Tinahones, Francisco J.; Fernández-Aranda, Fernando

    2015-01-01

    The prefrontal (PFC) and orbitofrontal cortex (OFC) appear to be associated with both executive functions and olfaction. However, there is little data relating olfactory processing and executive functions in humans. The present study aimed at exploring the role of olfaction on executive functioning, making a distinction between primary and more cognitive aspects of olfaction. Three executive tasks of similar difficulty were used. One was used to assess hot executive functions (Iowa Gambling Task-IGT), and two as a measure of cold executive functioning (Stroop Colour and Word Test-SCWT and Wisconsin Card Sorting Test-WCST). Sixty two healthy participants were included: 31 with normosmia and 31 with hyposmia. Olfactory abilities were assessed using the ‘‘Sniffin’ Sticks’’ test and the olfactory threshold, odour discrimination and odour identification measures were obtained. All participants were female, aged between 18 and 60. Results showed that participants with hyposmia displayed worse performance in decision making (IGT; Cohen’s-d = 0.91) and cognitive flexibility (WCST; Cohen’s-d between 0.54 and 0.68) compared to those with normosmia. Multiple regression adjusted by the covariates participants’ age and education level showed a positive association between odour identification and the cognitive inhibition response (SCWT-interference; Beta = 0.29; p = .034). The odour discrimination capacity was not a predictor of the cognitive executive performance. Our results suggest that both hot and cold executive functions seem to be associated with higher-order olfactory functioning in humans. These results robustly support the hypothesis that olfaction and executive measures have a common neural substrate in PFC and OFC, and suggest that olfaction might be a reliable cognitive marker in psychiatric and neurologic disorders. PMID:26083418

  10. Assessing reliable human mobility patterns from higher order memory in mobile communications.

    PubMed

    Matamalas, Joan T; De Domenico, Manlio; Arenas, Alex

    2016-08-01

    Understanding how people move within a geographical area, e.g. a city, a country or the whole world, is fundamental in several applications, from predicting the spatio-temporal evolution of an epidemic to inferring migration patterns. Mobile phone records provide an excellent proxy of human mobility, showing that movements exhibit a high level of memory. However, the precise role of memory in widely adopted proxies of mobility, as mobile phone records, is unknown. Here we use 560 million call detail records from Senegal to show that standard Markovian approaches, including higher order ones, fail in capturing real mobility patterns and introduce spurious movements never observed in reality. We introduce an adaptive memory-driven approach to overcome such issues. At variance with Markovian models, it is able to realistically model conditional waiting times, i.e. the probability to stay in a specific area depending on individuals' historical movements. Our results demonstrate that in standard mobility models the individuals tend to diffuse faster than observed in reality, whereas the predictions of the adaptive memory approach significantly agree with observations. We show that, as a consequence, the incidence and the geographical spread of a disease could be inadequately estimated when standard approaches are used, with crucial implications on resources deployment and policy-making during an epidemic outbreak. PMID:27581479

  11. Evaluation of layer thickness in human teeth using higher-order-mode leaky Lamb wave interdigital transducers

    SciTech Connect

    Toda, Shinji; Fujita, Takeshi; Arakawa, Hirohisa; Toda, Kohji

    2005-03-01

    An ultrasonic nondestructive evaluation technique of the layer thickness in human teeth is proposed using a leaky Lamb wave device with two arch-shaped interdigital transducers, operating at a plate/water interface. The use of a higher-order-mode leaky Lamb wave with a phase velocity higher than the longitudinal wave velocity in the human tooth is essential to detect reflected ultrasound beams from the tooth section The layer thickness of dentin, estimated from the measured time interval between two reflected echoes, is in good agreement with the optically measured data.

  12. Deletion of DXZ4 on the human inactive X chromosome alters higher-order genome architecture.

    PubMed

    Darrow, Emily M; Huntley, Miriam H; Dudchenko, Olga; Stamenova, Elena K; Durand, Neva C; Sun, Zhuo; Huang, Su-Chen; Sanborn, Adrian L; Machol, Ido; Shamim, Muhammad; Seberg, Andrew P; Lander, Eric S; Chadwick, Brian P; Aiden, Erez Lieberman

    2016-08-01

    During interphase, the inactive X chromosome (Xi) is largely transcriptionally silent and adopts an unusual 3D configuration known as the "Barr body." Despite the importance of X chromosome inactivation, little is known about this 3D conformation. We recently showed that in humans the Xi chromosome exhibits three structural features, two of which are not shared by other chromosomes. First, like the chromosomes of many species, Xi forms compartments. Second, Xi is partitioned into two huge intervals, called "superdomains," such that pairs of loci in the same superdomain tend to colocalize. The boundary between the superdomains lies near DXZ4, a macrosatellite repeat whose Xi allele extensively binds the protein CCCTC-binding factor. Third, Xi exhibits extremely large loops, up to 77 megabases long, called "superloops." DXZ4 lies at the anchor of several superloops. Here, we combine 3D mapping, microscopy, and genome editing to study the structure of Xi, focusing on the role of DXZ4 We show that superloops and superdomains are conserved across eutherian mammals. By analyzing ligation events involving three or more loci, we demonstrate that DXZ4 and other superloop anchors tend to colocate simultaneously. Finally, we show that deleting DXZ4 on Xi leads to the disappearance of superdomains and superloops, changes in compartmentalization patterns, and changes in the distribution of chromatin marks. Thus, DXZ4 is essential for proper Xi packaging. PMID:27432957

  13. Deletion of DXZ4 on the human inactive X chromosome alters higher-order genome architecture

    PubMed Central

    Darrow, Emily M.; Huntley, Miriam H.; Dudchenko, Olga; Stamenova, Elena K.; Durand, Neva C.; Sun, Zhuo; Huang, Su-Chen; Sanborn, Adrian L.; Machol, Ido; Shamim, Muhammad; Seberg, Andrew P.; Lander, Eric S.; Chadwick, Brian P.; Aiden, Erez Lieberman

    2016-01-01

    During interphase, the inactive X chromosome (Xi) is largely transcriptionally silent and adopts an unusual 3D configuration known as the “Barr body.” Despite the importance of X chromosome inactivation, little is known about this 3D conformation. We recently showed that in humans the Xi chromosome exhibits three structural features, two of which are not shared by other chromosomes. First, like the chromosomes of many species, Xi forms compartments. Second, Xi is partitioned into two huge intervals, called “superdomains,” such that pairs of loci in the same superdomain tend to colocalize. The boundary between the superdomains lies near DXZ4, a macrosatellite repeat whose Xi allele extensively binds the protein CCCTC-binding factor. Third, Xi exhibits extremely large loops, up to 77 megabases long, called “superloops.” DXZ4 lies at the anchor of several superloops. Here, we combine 3D mapping, microscopy, and genome editing to study the structure of Xi, focusing on the role of DXZ4. We show that superloops and superdomains are conserved across eutherian mammals. By analyzing ligation events involving three or more loci, we demonstrate that DXZ4 and other superloop anchors tend to colocate simultaneously. Finally, we show that deleting DXZ4 on Xi leads to the disappearance of superdomains and superloops, changes in compartmentalization patterns, and changes in the distribution of chromatin marks. Thus, DXZ4 is essential for proper Xi packaging. PMID:27432957

  14. Higher order stationary subspace analysis

    NASA Astrophysics Data System (ADS)

    Panknin, Danny; von Bünau, Paul; Kawanabe, Motoaki; Meinecke, Frank C.; Müller, Klaus-Robert

    2016-03-01

    Non-stationarity in data is an ubiquitous problem in signal processing. The recent stationary subspace analysis procedure (SSA) has enabled to decompose such data into a stationary subspace and a non-stationary part respectively. Algorithmically only weak non- stationarities could be tackled by SSA. The present paper takes the conceptual step generalizing from the use of first and second moments as in SSA to higher order moments, thus defining the proposed higher order stationary subspace analysis procedure (HOSSA). The paper derives the novel procedure and shows simulations. An obvious trade-off between the necessity of estimating higher moments and the accuracy and robustness with which they can be estimated is observed. In an ideal setting of plenty of data where higher moment information is dominating our novel approach can win against standard SSA. However, with limited data, even though higher moments actually dominate the underlying data, still SSA may arrive on par.

  15. Quantitative assessment of higher-order chromatin structure of the INK4/ARF locus in human senescent cells.

    PubMed

    Hirosue, Akiyuki; Ishihara, Ko; Tokunaga, Kazuaki; Watanabe, Takehisa; Saitoh, Noriko; Nakamoto, Masafumi; Chandra, Tamir; Narita, Masashi; Shinohara, Masanori; Nakao, Mitsuyoshi

    2012-06-01

    Somatic cells can be reset to oncogene-induced senescent (OIS) cells or induced pluripotent stem (iPS) cells by expressing specified factors. The INK4/ARF locus encodes p15(INK4b) , ARF, and p16(INK4a) genes in human chromosome 9p21, the products of which are known as common key reprogramming regulators. Compared with growing fibroblasts, the CCCTC-binding factor CTCF is remarkably up-regulated in iPS cells with silencing of the three genes in the locus and is reversely down-regulated in OIS cells with high expression of p15(INK4b) and p16(INK4a) genes. There are at least three CTCF-enriched sites in the INK4/ARF locus, which possess chromatin loop-forming activities. These CTCF-enriched sites and the p16(INK4a) promoter associate to form compact chromatin loops in growing fibroblasts, while CTCF depletion disrupts the loop structure. Interestingly, the loose chromatin structure is found in OIS cells. In addition, the INK4/ARF locus has an intermediate type of chromatin compaction in iPS cells. These results suggest that senescent cells have distinct higher-order chromatin signature in the INK4/ARF locus. PMID:22340434

  16. Higher order turbulence closure models

    NASA Technical Reports Server (NTRS)

    Amano, Ryoichi S.; Chai, John C.; Chen, Jau-Der

    1988-01-01

    Theoretical models are developed and numerical studies conducted on various types of flows including both elliptic and parabolic. The purpose of this study is to find better higher order closure models for the computations of complex flows. This report summarizes three new achievements: (1) completion of the Reynolds-stress closure by developing a new pressure-strain correlation; (2) development of a parabolic code to compute jets and wakes; and, (3) application to a flow through a 180 deg turnaround duct by adopting a boundary fitted coordinate system. In the above mentioned models near-wall models are developed for pressure-strain correlation and third-moment, and incorporated into the transport equations. This addition improved the results considerably and is recommended for future computations. A new parabolic code to solve shear flows without coordinate tranformations is developed and incorporated in this study. This code uses the structure of the finite volume method to solve the governing equations implicitly. The code was validated with the experimental results available in the literature.

  17. Higher order architecture of collections of objects

    NASA Astrophysics Data System (ADS)

    Baas, Nils A.

    2015-01-01

    We show that on an arbitrary collection of objects there is a wide variety of higher order architectures governed by hyperstructures. Higher order gluing, local to global processes, fusion of collections, bridges and higher order types are discussed. We think that these types of architectures may have interesting applications in many areas of science.

  18. Generalized structure of higher order nonclassicality

    NASA Astrophysics Data System (ADS)

    Verma, Amit; Pathak, Anirban

    2010-02-01

    A generalized notion of higher order nonclassicality (in terms of higher order moments) is introduced. Under this generalized framework of higher order nonclassicality, conditions of higher order squeezing and higher order subpoissonian photon statistics are derived. A simpler form of the Hong-Mandel higher order squeezing criterion is derived under this framework by using an operator ordering theorem introduced by us in [A. Pathak, J. Phys. A 33 (2000) 5607]. It is also generalized for multi-photon Bose operators of Brandt and Greenberg. Similarly, condition for higher order subpoissonian photon statistics is derived by normal ordering of higher powers of number operator. Further, with the help of simple density matrices, it is shown that the higher order antibunching (HOA) and higher order subpoissonian photon statistics (HOSPS) are not the manifestation of the same phenomenon and consequently it is incorrect to use the condition of HOA as a test of HOSPS. It is also shown that the HOA and HOSPS may exist even in absence of the corresponding lower order phenomenon. Binomial state, nonlinear first order excited squeezed state (NLESS) and nonlinear vacuum squeezed state (NLVSS) are used as examples of quantum state and it is shown that these states may show higher order nonclassical characteristics. It is observed that the Binomial state which is always antibunched, is not always higher order squeezed and NLVSS which shows higher order squeezing does not show HOSPS and HOA. The opposite is observed in NLESS and consequently it is established that the HOSPS and HOS are two independent signatures of higher order nonclassicality.

  19. Higher-Order Mentalising and Executive Functioning

    PubMed Central

    2015-01-01

    Higher-order mentalising is the ability to represent the beliefs and desires of other people at multiple, iterated levels – a capacity that sets humans apart from other species. However, there has not yet been a systematic attempt to determine what cognitive processes underlie this ability. Here we present three correlational studies assessing the extent to which performance on higher-order mentalising tasks relates to emotion recognition, self-reported empathy and self-inhibition. In Study 1a and 1b, examining emotion recognition and empathy, a relationship was identified between individual differences in the ability to mentalise and an emotion recognition task (the Reading the Mind in the Eyes task), but no correlation was found with the Empathy Quotient, a self-report scale of empathy. Study 2 investigated whether a relationship exists between individual mentalising abilities and four different forms of self-inhibition: motor inhibition, executive inhibition, automatic imitation and temporal discounting. Results demonstrate that only temporal discounting performance relates to mentalising ability; suggesting that cognitive skills relevant to representation of the minds of others’ are not influenced by the ability to perform more basic inhibition. Higher-order mentalising appears to rely on the cognitive architecture that serves both low-level social cognition (emotion recognition), and complex forms of inhibition. PMID:26543298

  20. Higher-order organization of complex networks.

    PubMed

    Benson, Austin R; Gleich, David F; Leskovec, Jure

    2016-07-01

    Networks are a fundamental tool for understanding and modeling complex systems in physics, biology, neuroscience, engineering, and social science. Many networks are known to exhibit rich, lower-order connectivity patterns that can be captured at the level of individual nodes and edges. However, higher-order organization of complex networks--at the level of small network subgraphs--remains largely unknown. Here, we develop a generalized framework for clustering networks on the basis of higher-order connectivity patterns. This framework provides mathematical guarantees on the optimality of obtained clusters and scales to networks with billions of edges. The framework reveals higher-order organization in a number of networks, including information propagation units in neuronal networks and hub structure in transportation networks. Results show that networks exhibit rich higher-order organizational structures that are exposed by clustering based on higher-order connectivity patterns. PMID:27387949

  1. Resonant radiation from oscillating higher order solitons.

    PubMed

    Driben, R; Yulin, A V; Efimov, A

    2015-07-27

    We present radiation mechanism exhibited by a higher order soliton. In a course of its evolution the higher-order soliton emits polychromatic radiation resulting in formation of multipeak frequency comb-like spectral band. The shape and spectral position of this band can be effectively controlled by the relative strength of the third order dispersion. An analytical description is corroborated by numerical simulations. It is shown that for longer pulses the described effect persists also under the action of higher order perturbations such as Raman and self-steepening. PMID:26367574

  2. Resonant radiation from oscillating higher order solitons

    SciTech Connect

    Driben, R.; Yulin, A. V.; Efimov, A.

    2015-07-15

    We present radiation mechanism exhibited by a higher order soliton. In a course of its evolution the higher-order soliton emits polychromatic radiation resulting in formation of multipeak frequency comb-like spectral band. The shape and spectral position of this band can be effectively controlled by the relative strength of the third order dispersion. An analytical description is corroborated by numerical simulations. Research showed that for longer pulses the described effect persists also under the action of higher order perturbations such as Raman and self-steepening.

  3. Higher order differential-integral microphone arrays.

    PubMed

    Abhayapala, Thushara D; Gupta, Aastha

    2010-05-01

    This paper develops theory to design higher order directional microphone arrays. The proposed higher order designs have similar inter sensor spacings as traditional first and second order differential arrays. The Jacobi-Anger expansion is used to exploit the underlying structure of microphone signals from pairs of closely spaced sensors. Specifically, the difference and sum of these microphone signals are processed to design the novel directional array. PMID:21117719

  4. Higher order Godunov schemes for isothermal hydrodynamics

    NASA Technical Reports Server (NTRS)

    Balsara, Dinshaw S.

    1994-01-01

    In this paper we construct higher order Godunov schemes for isothermal flow. Isothermal hydrodynamics serves as a good representation for several systems of astrophysical interest. The schemes designed here have second-order accuracy in space and time and some are third-order accurate for advection. Moreover, several ingredients of these schemes are essential components of even higher order. The methods designed here have excellent ability to represent smooth flow yet capture shocks with high resolution. Several test problems are presented. The algorithms presented here are compared with other algorithms having a comparable formal order of accuracy.

  5. Higher-Order Neural Networks Recognize Patterns

    NASA Technical Reports Server (NTRS)

    Reid, Max B.; Spirkovska, Lilly; Ochoa, Ellen

    1996-01-01

    Networks of higher order have enhanced capabilities to distinguish between different two-dimensional patterns and to recognize those patterns. Also enhanced capabilities to "learn" patterns to be recognized: "trained" with far fewer examples and, therefore, in less time than necessary to train comparable first-order neural networks.

  6. Using Reflection to Develop Higher Order Processes

    ERIC Educational Resources Information Center

    Lerch, Carol; Bilics, Andrea; Colley, Binta

    2006-01-01

    The main purpose of this study was to look at how we used specific writing assignments in our courses to encourage metacognitive reflection in order to increase the learning that takes place. The study also aimed to aid in the development of higher order processing skills through the development of student reflection. The students involved in the…

  7. Higher-order awareness, misrepresentation and function.

    PubMed

    Rosenthal, David

    2012-05-19

    Conscious mental states are states we are in some way aware of. I compare higher-order theories of consciousness, which explain consciousness by appeal to such higher-order awareness (HOA), and first-order theories, which do not, and I argue that higher-order theories have substantial explanatory advantages. The higher-order nature of our awareness of our conscious states suggests an analogy with the metacognition that figures in the regulation of psychological processes and behaviour. I argue that, although both consciousness and metacognition involve higher-order psychological states, they have little more in common. One thing they do share is the possibility of misrepresentation; just as metacognitive processing can misrepresent one's cognitive states and abilities, so the HOA in virtue of which one's mental states are conscious can, and sometimes does, misdescribe those states. A striking difference between the two, however, has to do with utility for psychological processing. Metacognition has considerable benefit for psychological processing; in contrast, it is unlikely that there is much, if any, utility to mental states' being conscious over and above the utility those states have when they are not conscious. PMID:22492758

  8. Higher-order awareness, misrepresentation and function

    PubMed Central

    Rosenthal, David

    2012-01-01

    Conscious mental states are states we are in some way aware of. I compare higher-order theories of consciousness, which explain consciousness by appeal to such higher-order awareness (HOA), and first-order theories, which do not, and I argue that higher-order theories have substantial explanatory advantages. The higher-order nature of our awareness of our conscious states suggests an analogy with the metacognition that figures in the regulation of psychological processes and behaviour. I argue that, although both consciousness and metacognition involve higher-order psychological states, they have little more in common. One thing they do share is the possibility of misrepresentation; just as metacognitive processing can misrepresent one's cognitive states and abilities, so the HOA in virtue of which one's mental states are conscious can, and sometimes does, misdescribe those states. A striking difference between the two, however, has to do with utility for psychological processing. Metacognition has considerable benefit for psychological processing; in contrast, it is unlikely that there is much, if any, utility to mental states' being conscious over and above the utility those states have when they are not conscious. PMID:22492758

  9. Breastfeeding twins and higher-order multiples.

    PubMed

    Gromada, K K; Spangler, A K

    1998-01-01

    The benefits of breastfeeding for pre-term and full-term infants are well documented. Breastfeeding facilitates maternal-infant attachment, provides optimal infant nutrition and immunologic protection, and minimizes economic impact. These benefits are multiplied with twins and higher-order multiples, who often are born at risk. Supporting a mother as she initiates and continues to breastfeed one infant requires specific knowledge and skills. Health professionals need additional knowledge and skills if they are to provide appropriate assessment, intervention, and support when a mother breastfeeds twins or higher-order multiples. PMID:9684207

  10. Higher-order dielectrophoresis of nonspherical particles

    NASA Astrophysics Data System (ADS)

    Nili, Hossein; Green, Nicolas G.

    2014-06-01

    Higher-order terms of dielectrophoretic (DEP) force are commonly ignored by invoking the simplifying dipole approximation. Concurrently, the trend towards micro- and nano-electrode structures in DEP design is bringing about an increasing number of instances where the approximation is expected to lose reliability. The case is severe for nonspherical particles (the shape of many biological particles) due to the shape-dependent nature of dielectric polarization. However, there is a lack of analytical means to determine multipole moments of nonspherical particles, numerical calculations of the same are regarded as unreliable, and there is a prevalence for higher-order force considerations to be ignored. As a result, the dipole approximation is used and/or nonspherical particles are approximated as spheres. This work proves the inefficacy of current qualitative criteria for the reliability of the dipole approximation and presents a quantitative substitute, with verified accuracy, that enables precise determination of the extent to which the dipole approximation would be reliable, and if found unreliable, corrects the approximation by adding second- and third-order terms of the DEP force. The effects of field nonuniformity, electrode design, and particle shape and aspect ratio on the significance of higher-order DEP forces is quantitatively analyzed. The results show that higher-order DEP forces are indeed of substantially increased significance for nonspherical particles; in the cases examined in this work, multipolar terms are seen to constitute more than 40% of the total force on ellipsoidal and cylindrical particles. It is further shown that approximating nonspherical particles as spheres of similar dimensions is subject to substantial error. Last, the substantial importance of the electrode design in influencing higher-order forces is shown.

  11. Assessing Higher Order Thinking in Mathematics.

    ERIC Educational Resources Information Center

    Kulm, Gerald, Ed.

    This book explores current theory, research, practice, and policy in the assessment of higher order thinking in mathematics, focusing on the elementary and secondary grades. Current knowledge and research on mathematics learning and testing is synthesized. Examples of innovative test items for classroom use and state assessment programs are…

  12. Analogy, higher order thinking, and education.

    PubMed

    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. PMID:26263071

  13. Higher Order Thinking in the Dance Studio

    ERIC Educational Resources Information Center

    Moffett, Ann-Thomas

    2012-01-01

    The author identifies higher order thinking as an essential component of dance training for students of all ages and abilities. Weaving together insights from interviews with experts in the field of dance education with practical pedagogical applications within an Improvisation and Composition class for talented and gifted youth, this article…

  14. Enhanced higher order parametric x radiation production

    NASA Astrophysics Data System (ADS)

    Dinova, Kay L.

    1992-12-01

    This thesis examines parametric x-radiation (PXR) which is the Bragg scattering of the virtual photons associated with the Coulomb field of relativistic charged particle from the atomic planes of a crystal. Higher order parametric x-radiation from the (002) planes of a thick mosaic graphite crystal have been observed. The raw PXR data was collected using a SiLi detector and a Pulse Height Analyzer (PHA) software program. The data was corrected for various effects including attenuation, detector drift, and efficiency. The absolute number of photons per electron was obtained by using the fluorescent x-ray yield from a tin foil backing on the graphite crystal to determine the LINAC current. The number of photons per electron observed greatly exceeds the expected values. Comparison of the ratio of intensity of a given order to the first order I(n)/I(I) to the theoretical ratio shows that the ratios increase with order. Not only is the absolute intensity greater than expected, but the higher orders (compared to the first order) are larger than expected. Lastly, the intensity for various crystal angle orientations and a fixed detector angle was measured.

  15. Human Capital, (Human) Capabilities and Higher Education

    ERIC Educational Resources Information Center

    Le Grange, L.

    2011-01-01

    In this article I initiate a debate into the (de)merits of human capital theory and human capability theory and discuss implications of the debate for higher education. Human capital theory holds that economic growth depends on investment in education and that economic growth is the basis for improving the quality of human life. Human capable…

  16. The regular state in higher order gravity

    NASA Astrophysics Data System (ADS)

    Cotsakis, Spiros; Kadry, Seifedine; Trachilis, Dimitrios

    2016-08-01

    We consider the higher-order gravity theory derived from the quadratic Lagrangian R + 𝜖R2 in vacuum as a first-order (ADM-type) system with constraints, and build time developments of solutions of an initial value formulation of the theory. We show that all such solutions, if analytic, contain the right number of free functions to qualify as general solutions of the theory. We further show that any regular analytic solution which satisfies the constraints and the evolution equations can be given in the form of an asymptotic formal power series expansion.

  17. Performance assessment of higher order thinking.

    PubMed

    Griffin, Patrick

    2014-01-01

    This article describes a study investigating the effect of intervention on student problem solving and higher order competency development using a series of complex numeracy performance tasks (Airasian and Russell, 2008). The tasks were sequenced to promote and monitor student development towards hypothetico-deductive reasoning. Using Rasch partial credit analysis (Wright and Masters, 1982) to calibrate the tasks and analysis of residual gain scores to examine the effect of class and school membership, the study illustrates how directed intervention can improve students' higher order competency skills. This paper demonstrates how the segmentation defined by Wright and Masters can offer a basis for interpreting the construct underlying a test and how segment definitions can deliver targeted interventions. Implications for teacher intervention and teaching mentor schemes are considered. The article also discusses multilevel regression models that differentiate class and school effects, and describes a process for generating, testing and using value added models. PMID:24518581

  18. Hydrogen peroxide mediates higher order chromatin degradation.

    PubMed

    Bai, H; Konat, G W

    2003-01-01

    Although a large body of evidence supports a causative link between oxidative stress and neurodegeneration, the mechanisms are still elusive. We have recently demonstrated that hydrogen peroxide (H(2)O(2)), the major mediator of oxidative stress triggers higher order chromatin degradation (HOCD), i.e. excision of chromatin loops at the matrix attachment regions (MARs). The present study was designed to determine the specificity of H(2)O(2) in respect to HOCD induction. Rat glioma C6 cells were exposed to H(2)O(2) and other oxidants, and the fragmentation of genomic DNA was assessed by field inversion gel electrophoresis (FIGE). S1 digestion before FIGE was used to detect single strand fragmentation. The exposure of C6 cells to H(2)O(2) induced a rapid and extensive HOCD. Thus, within 30 min, total chromatin was single strandedly digested into 50 kb fragments. Evident HOCD was elicited by H(2)O(2) at concentrations as low as 5 micro M. HOCD was mostly reversible during 4-8h following the removal of H(2)O(2) from the medium indicating an efficient relegation of the chromatin fragments. No HOCD was induced by H(2)O(2) in isolated nuclei indicating that HOCD-endonuclease is activated indirectly by cytoplasmic signal pathways triggered by H(2)O(2). The exposure of cells to a synthetic peroxide, i.e. tert-butyrylhydroperoxide (tBH) also induced HOCD, but to a lesser extent than H(2)O(2). Contrary to the peroxides, the exposure of cells to equitoxic concentration of hypochlorite and spermine NONOate, a nitric oxide generator, failed to induce rapid HOCD. These results indicate that rapid HOCD is not a result of oxidative stress per se, but is rather triggered by signaling cascades initiated specifically by H(2)O(2). Furthermore, the rapid and extensive HOCD was observed in several rat and human cell lines challenged with H(2)O(2), indicating that the process is not restricted to glial cells, but rather represents a general response of cells to H(2)O(2). PMID:12421592

  19. Visualizing higher order finite elements. Final report

    SciTech Connect

    Thompson, David C; Pebay, Philippe Pierre

    2005-11-01

    This report contains an algorithm for decomposing higher-order finite elements into regions appropriate for isosurfacing and proves the conditions under which the algorithm will terminate. Finite elements are used to create piecewise polynomial approximants to the solution of partial differential equations for which no analytical solution exists. These polynomials represent fields such as pressure, stress, and momentum. In the past, these polynomials have been linear in each parametric coordinate. Each polynomial coefficient must be uniquely determined by a simulation, and these coefficients are called degrees of freedom. When there are not enough degrees of freedom, simulations will typically fail to produce a valid approximation to the solution. Recent work has shown that increasing the number of degrees of freedom by increasing the order of the polynomial approximation (instead of increasing the number of finite elements, each of which has its own set of coefficients) can allow some types of simulations to produce a valid approximation with many fewer degrees of freedom than increasing the number of finite elements alone. However, once the simulation has determined the values of all the coefficients in a higher-order approximant, tools do not exist for visual inspection of the solution. This report focuses on a technique for the visual inspection of higher-order finite element simulation results based on decomposing each finite element into simplicial regions where existing visualization algorithms such as isosurfacing will work. The requirements of the isosurfacing algorithm are enumerated and related to the places where the partial derivatives of the polynomial become zero. The original isosurfacing algorithm is then applied to each of these regions in turn.

  20. Representing higher-order dependencies in networks

    PubMed Central

    Xu, Jian; Wickramarathne, Thanuka L.; Chawla, Nitesh V.

    2016-01-01

    To ensure the correctness of network analysis methods, the network (as the input) has to be a sufficiently accurate representation of the underlying data. However, when representing sequential data from complex systems, such as global shipping traffic or Web clickstream traffic as networks, conventional network representations that implicitly assume the Markov property (first-order dependency) can quickly become limiting. This assumption holds that, when movements are simulated on the network, the next movement depends only on the current node, discounting the fact that the movement may depend on several previous steps. However, we show that data derived from many complex systems can show up to fifth-order dependencies. In these cases, the oversimplifying assumption of the first-order network representation can lead to inaccurate network analysis results. To address this problem, we propose the higher-order network (HON) representation that can discover and embed variable orders of dependencies in a network representation. Through a comprehensive empirical evaluation and analysis, we establish several desirable characteristics of HON, including accuracy, scalability, and direct compatibility with the existing suite of network analysis methods. We illustrate how HON can be applied to a broad variety of tasks, such as random walking, clustering, and ranking, and we demonstrate that, by using it as input, HON yields more accurate results without any modification to these tasks. PMID:27386539

  1. Discrimination of higher-order textures.

    PubMed

    Nothdurft, H C

    1985-01-01

    Arrays of figural elements differing in certain features ('textons') may be visually segregated to yield the impression of a global figure of different texture. This fact was used to construct texture patterns of a higher level of complexity. In microstructure, these patterns reveal regular arrays of distinguishable figural elements, the segregation of which can be predicted from previous studies of human texture sensitivity. In macrostructure, clusters of such elements form new figural elements which, when repeated over space, themselves give the impression of texture at a perceptually higher level. Discrimination of such macrostructure textures was found to place similar restrictions on the form of figural elements as those of texture discrimination at the microstructure level. PMID:3836385

  2. A Novel Higher Order Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Xu, Shuxiang

    2010-05-01

    In this paper a new Higher Order Neural Network (HONN) model is introduced and applied in several data mining tasks. Data Mining extracts hidden patterns and valuable information from large databases. A hyperbolic tangent function is used as the neuron activation function for the new HONN model. Experiments are conducted to demonstrate the advantages and disadvantages of the new HONN model, when compared with several conventional Artificial Neural Network (ANN) models: Feedforward ANN with the sigmoid activation function; Feedforward ANN with the hyperbolic tangent activation function; and Radial Basis Function (RBF) ANN with the Gaussian activation function. The experimental results seem to suggest that the new HONN holds higher generalization capability as well as abilities in handling missing data.

  3. Finesky -- removing higher order sky residuals

    NASA Astrophysics Data System (ADS)

    Dahlen, Tomas; Grumm, David

    2010-07-01

    We report on a new IRAF task called finesky that removes higher order sky residuals in NICMOS images by creating a masked median image of the observed sky. This median sky image is thereafter subtracted from the science images. A residual signal after image processing using the calibration software calnica may be present due to reference files that do not sufficiently match the conditions of the observations. This includes a slight mismatch in the dark current or the flat-field corrections. The task described here can also used to create sky flat-field images.

  4. Higher-order brane gravity models

    SciTech Connect

    Dabrowski, Mariusz P.; Balcerzak, Adam

    2010-06-23

    We discuss a very general theory of gravity, of which Lagrangian is an arbitrary function of the curvature invariants, on the brane. In general, the formulation of the junction conditions (except for Euler characteristics such as Gauss-Bonnet term) leads to the powers of the delta function and requires regularization. We suggest the way to avoid such a problem by imposing the metric and its first derivative to be regular at the brane, the second derivative to have a kink, the third derivative of the metric to have a step function discontinuity, and no sooner as the fourth derivative of the metric to give the delta function contribution to the field equations. Alternatively, we discuss the reduction of the fourth-order gravity to the second order theory by introducing extra scalar and tensor fields: the scalaron and the tensoron. In order to obtain junction conditions we apply two methods: the application of the Gauss-Codazzi formalism and the application of the generalized Gibbons-Hawking boundary terms which are appended to the appropriate actions. In the most general case we derive junction conditions without assuming the continuity of the scalaron and the tensoron on the brane. The derived junction conditions can serve studying the cosmological implications of the higher-order brane gravity models.

  5. Theorem Proving In Higher Order Logics

    NASA Technical Reports Server (NTRS)

    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.

  6. Higher-Order Item Response Models for Hierarchical Latent Traits

    ERIC Educational Resources Information Center

    Huang, Hung-Yu; Wang, Wen-Chung; Chen, Po-Hsi; Su, Chi-Ming

    2013-01-01

    Many latent traits in the human sciences have a hierarchical structure. This study aimed to develop a new class of higher order item response theory models for hierarchical latent traits that are flexible in accommodating both dichotomous and polytomous items, to estimate both item and person parameters jointly, to allow users to specify…

  7. Higher Order Thermal Lattice Boltzmann Model

    NASA Astrophysics Data System (ADS)

    Sorathiya, Shahajhan; Ansumali, Santosh

    2013-03-01

    Lattice Boltzmann method (LBM) modelling of thermal flows, compressible and micro flows requires an accurate velocity space discretization. The sub optimality of Gauss-Hermite quadrature in this regard is well known. Most of the thermal LBM in the past have suffered from instability due to lack of proper H-theorem and accuracy. Motivated from these issues, the present work develops along the two works and and imposes an eighth higher order moment to get correct thermal physics. We show that this can be done by adding just 6 more velocities to D3Q27 model and obtain a ``multi-speed on lattice thermal LBM'' with 33 velocities in 3D and calO (u4) and calO (T4) accurate fieq with a consistent H-theorem and inherent numerical stability. Simulations for Rayleigh-Bernard as well as velocity and temperature slip in micro flows matches with analytical results. Lid driven cavity set up for grid convergence is studied. Finally, a novel data structure is developed for HPC. The authors express their gratitude for computational resources and financial support provide by Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore, India.

  8. Higher-order motion sensitivity in fly visual circuits.

    PubMed

    Lee, Yu-Jen; Nordström, Karin

    2012-05-29

    In higher-order motion stimuli, the direction of object motion does not follow the direction of luminance change. Such stimuli could be generated by the wing movements of a flying butterfly and further complicated by its motion in and out of shadows. Human subjects readily perceive the direction of higher-order motion, although this stands in stark contrast to prevailing motion vision models. Flies and humans compute motion in similar ways, and because flies behaviorally track bars containing higher-order motion cues, they become an attractive model system for investigating the neurophysiology underlying higher-order motion sensitivity. We here use intracellular electrophysiology of motion-vision-sensitive neurons in the hoverfly lobula plate to quantify responses to stimuli containing higher-order motion. We show that motion sensitivity can be broken down into two separate streams, directionally coding for elementary motion and figure motion, respectively, and that responses to Fourier and theta motion can be predicted from these. The sensitivity is affected both by the stimulus' time course and by the neuron's underlying receptive field. Responses to preferred-direction theta motion are sexually dimorphic and particularly robust along the visual midline. PMID:22586123

  9. Higher-order motion sensitivity in fly visual circuits

    PubMed Central

    Lee, Yu-Jen; Nordström, Karin

    2012-01-01

    In higher-order motion stimuli, the direction of object motion does not follow the direction of luminance change. Such stimuli could be generated by the wing movements of a flying butterfly and further complicated by its motion in and out of shadows. Human subjects readily perceive the direction of higher-order motion, although this stands in stark contrast to prevailing motion vision models. Flies and humans compute motion in similar ways, and because flies behaviorally track bars containing higher-order motion cues, they become an attractive model system for investigating the neurophysiology underlying higher-order motion sensitivity. We here use intracellular electrophysiology of motion-vision–sensitive neurons in the hoverfly lobula plate to quantify responses to stimuli containing higher-order motion. We show that motion sensitivity can be broken down into two separate streams, directionally coding for elementary motion and figure motion, respectively, and that responses to Fourier and theta motion can be predicted from these. The sensitivity is affected both by the stimulus’ time course and by the neuron’s underlying receptive field. Responses to preferred-direction theta motion are sexually dimorphic and particularly robust along the visual midline. PMID:22586123

  10. Higher Education Guidelines for Executive Order 11246.

    ERIC Educational Resources Information Center

    Office for Civil Rights (DHEW), Washington, DC.

    This document presents and explains Executive Order 11246, the order prohibiting discrimination under federal contracts in colleges and universities. Part one of the document describes the legal provisions of the order; part two deals with personnel policies and practices including recruitment, hiring, anti-nepotism policies, training, promotion,…

  11. On the higher orders of hyperspherical harmonics

    NASA Astrophysics Data System (ADS)

    Arribas, E.; Navarro, J.; Fabre de la Ripelle, M.

    1983-08-01

    We suggest a procedure to evaluate matrix elements between hyperspherical harmonics of any order. The method is based on the hyperspherical expansion of a Slater determinant constructed with oscillator wavefunctions. Explicit formulas are given for all matrix elements up to order Lm+2.

  12. Higher-order corrections in threshold resummation

    NASA Astrophysics Data System (ADS)

    Moch, S.; Vermaseren, J. A. M.; Vogt, A.

    2005-10-01

    We extend the threshold resummation exponents G in Mellin- N space to the fourth logarithmic (N 3LL) order collecting the terms αs2( to all orders in the strong coupling constant α. Comparing the results to our previous three-loop calculations for deep-inelastic scattering (DIS), we derive the universal coefficients B and B governing the final-state jet functions to order αs3, extending the previous quark and gluon results by one and two orders. A curious relation is found at second order between these quantities, the splitting functions and the large-angle soft emissions in Drell-Yan type processes. We study the numerical effect of the N 3LL corrections using both the fully exponentiated form and the expansion of the coefficient function in towers of logarithms.

  13. Constructing higher-order hydrodynamics: The third order

    NASA Astrophysics Data System (ADS)

    Grozdanov, Sašo; Kaplis, Nikolaos

    2016-03-01

    Hydrodynamics can be formulated as the gradient expansion of conserved currents in terms of the fundamental fields describing the near-equilibrium fluid flow. In the relativistic case, the Navier-Stokes equations follow from the conservation of the stress-energy tensor to first order in derivatives. In this paper, we go beyond the presently understood second-order hydrodynamics and discuss the systematization of obtaining the hydrodynamic expansion to an arbitrarily high order. As an example of the algorithm that we present, we fully classify the gradient expansion at third order for neutral fluids in four dimensions, thus finding the most general next-to-leading-order corrections to the relativistic Navier-Stokes equations in curved space-time. In doing so, we list 20 new transport coefficient candidates in the conformal case and 68 in the nonconformal case. As we do not consider any constraints that could potentially arise from the local entropy current analysis, this is the maximal possible set of neutral third-order transport coefficients. To investigate the physical implications of these new transport coefficients, we obtain the third-order corrections to the linear dispersion relations that describe the propagation of diffusion and sound waves in relativistic fluids. We also compute the corrections to the scalar (spin-2) two-point correlation function of the third-order stress-energy tensor. Furthermore, as an example of a nonlinear hydrodynamic flow, we calculate the third-order corrections to the energy density of a boost-invariant Bjorken flow. Finally, we apply our field theoretic results to the N =4 supersymmetric Yang-Mills fluid at infinite 't Hooft coupling and an infinite number of colors to find the values of five new linear combinations of the conformal transport coefficients.

  14. HIGHER ORDER HARD EDGE END FIELD EFFECTS.

    SciTech Connect

    BERG,J.S.

    2004-09-14

    In most cases, nonlinearities from magnets must be properly included in tracking and analysis to properly compute quantities of interest, in particular chromatic properties and dynamic aperture. One source of nonlinearities in magnets that is often important and cannot be avoided is the nonlinearity arising at the end of a magnet due to the longitudinal variation of the field at the end of the magnet. Part of this effect is independent of the longitudinal of the end. It is lowest order in the body field of the magnet, and is the result of taking a limit as the length over which the field at the end varies approaches zero. This is referred to as a ''hard edge'' end field. This effect has been computed previously to lowest order in the transverse variables. This paper describes a method to compute this effect to arbitrary order in the transverse variables, under certain constraints.

  15. Simulation Higher Order Language Requirements Study.

    ERIC Educational Resources Information Center

    Goodenough, John B.; Braun, Christine L.

    The definitions provided for high order language (HOL) requirements for programming flight training simulators are based on the analysis of programs written for a variety of simulators. Examples drawn from these programs are used to justify the need for certain HOL capabilities. A description of the general structure and organization of the…

  16. Moral Order and the Humanities.

    ERIC Educational Resources Information Center

    Howard, Thomas

    1980-01-01

    Argues that a society without reverence for myths and history inevitably falls prone to chaos and evil, pointing to abortion, Andy Warhol's celebrity, and Woodstock as evidence of this disintegration of society. Proposes that humanities education expose students to human experience based on some awesome and fixed moral order. (AYC)

  17. Invariant Higher-Order Variational Problems II

    NASA Astrophysics Data System (ADS)

    Gay-Balmaz, François; Holm, Darryl D.; Meier, David M.; Ratiu, Tudor S.; Vialard, François-Xavier

    2012-08-01

    Motivated by applications in computational anatomy, we consider a second-order problem in the calculus of variations on object manifolds that are acted upon by Lie groups of smooth invertible transformations. This problem leads to solution curves known as Riemannian cubics on object manifolds that are endowed with normal metrics. The prime examples of such object manifolds are the symmetric spaces. We characterize the class of cubics on object manifolds that can be lifted horizontally to cubics on the group of transformations. Conversely, we show that certain types of non-horizontal geodesic on the group of transformations project to cubics. Finally, we apply second-order Lagrange-Poincaré reduction to the problem of Riemannian cubics on the group of transformations. This leads to a reduced form of the equations that reveals the obstruction for the projection of a cubic on a transformation group to again be a cubic on its object manifold.

  18. Higher order diffractions from a circular disk

    NASA Technical Reports Server (NTRS)

    Marsland, Diane P.; Balanis, Constantine A.; Brumley, Stephen A.

    1987-01-01

    The backscattering from a circular disk is analyzed using the geometrical theory of diffraction. First-, second-, and third-order diffractions are included in the hard polarization analysis, while first-, second-, and third-order slope diffractions are included for soft polarization. Improvements in the prediction of the monostatic radar cross section over previous works are noted. For hard polarization, an excellent agreement is exhibited between experimental and theoretical results, while a very good agreement is noted for soft polarization. To further improve the soft polarization results for wide angles, a model for the creeping wave or circulating current on the edge of the disk is obtained and used to find an additional component of the backscattered field. The addition of this component significantly improves the results for wide angles, leading to excellent agreement for soft polarization also. An axial-caustic correction method using equivalent currents is also included in the analysis.

  19. Higher Order Macro Coefficients in Periodic Homogenization

    NASA Astrophysics Data System (ADS)

    Conca, Carlos; San Martin, Jorge; Smaranda, Loredana; Vanninathan, Muthusamy

    2011-09-01

    A first set of macro coefficients known as the homogenized coefficients appear in the homogenization of PDE on periodic structures. If energy is increased or scale is decreased, these coefficients do not provide adequate approximation. Using Bloch decomposition, it is first realized that the above coefficients correspond to the lowest energy and the largest scale. This naturally paves the way to introduce other sets of macro coefficients corresponding to higher energies and lower scales which yield better approximation. The next task is to compare their properties with those of the homogenized coefficients. This article reviews these developments along with some new results yet to be published.

  20. Higher-order terms in mode conversion

    NASA Astrophysics Data System (ADS)

    Swanson, D. G.

    1998-07-01

    The development of model equations to describe mode conversion and tunneling in an inhomogeneous plasma usually uses expansions of the Modified Bessel functions in the parameter λ=1/2k⊥2ρL2, keeping only the lowest possible order to demonstrate tunneling. With the high temperatures of fusion parameters, especially for fusion alpha particles, this parameter may not be small. It is shown here that the effective expansion parameter is really βj=2μ0njkTj/B02, the ratio of plasma pressure to the magnetic pressure.

  1. Systems with Higher-Order Modulation

    NASA Astrophysics Data System (ADS)

    Seimetz, Matthias

    With the objective of reducing costs per information bit in optical communication networks, per fibre capacities and optical transparent transmission lengths have been stepped up by the introduction of new technology in recent years. The innovation of the erbium-doped fibre amplifier (EDFA) at the beginning of the nineties facilitated long distances to be bridged without electro-optical conversion. Wavelength division multiplexing (WDM) technology allowed a lot of wavelength channels to be simultaneously transmitted over one fibre and to be amplified by one EDFA with high bandwidth, offering a huge network capacity. At this time, the modulation format of choice was the simple "on-off keying" (OOK), and there was no need for increasing spectral efficiency. The internet traffic growth during the nineties required increasing transmission rates. In that context, the transmission impairments of the optical fibre had to be counteracted and the application of differential binary phased shift keying (DBPSK) became an issue, providing for a higher robustness against nonlinear effects [1]. Moreover, the transmission behaviour of binary intensity modulation was optimized by using alternative optical pulse shapes such as return to zero (RZ) and by employing schemes with auxiliary phase coding, such as optical duobinary, which exhibits a higher tolerance against chromatic dispersion (CD). The capacity-distance product was further enhanced by applying optical dispersion compensation, Raman amplification and advanced optical fibres, as well as through electronic means, such as forward error correction (FEC) and the adaptive compensation of CD and polarization mode dispersion (PMD).

  2. Chromatin Higher-order Structure and Dynamics

    PubMed Central

    Woodcock, Christopher L.; Ghosh, Rajarshi P.

    2010-01-01

    The primary role of the nucleus as an information storage, retrieval, and replication site requires the physical organization and compaction of meters of DNA. Although it has been clear for many years that nucleosomes constitute the first level of chromatin compaction, this contributes a relatively small fraction of the condensation needed to fit the typical genome into an interphase nucleus or set of metaphase chromosomes, indicating that there are additional “higher order” levels of chromatin condensation. Identifying these levels, their interrelationships, and the principles that govern their occurrence has been a challenging and much discussed problem. In this article, we focus on recent experimental advances and the emerging evidence indicating that structural plasticity and chromatin dynamics play dominant roles in genome organization. We also discuss novel approaches likely to yield important insights in the near future, and suggest research areas that merit further study. PMID:20452954

  3. Higher Order Chromaticity Correction for ELIC

    NASA Astrophysics Data System (ADS)

    Sayed, Hisham; Bogacz, Alex

    2010-02-01

    The proposed electron collider lattice design with extremely low betas at the interaction Point IP (β*˜ 0.5cm) and the precedently large longitudinal acceptance of the collider ring (δp/p = 0.005) [1], makes the chromatic corrections of paramount importance. Here the chromatic effects of the final focus quadruples are corrected with two families of sextuples in a dispersive region; one family per plane. Each family consists of two pairs of sextuples located symmetrically around the interaction point IP. A confined dispersion wave around the IP is generated by two bending magnets (one at each side of the IP with mirror reflected Polarities) which also develop the vertical staking design. The resulting spherical aberrations induced by the sextuples are mitigated by design; the matching section optics features an inverse identity transformation between sextuples in each pair. A dedicated optics is placed in the matching region to implement sextuple orthogonality in both planes, which in turns minimizes the required sextuple strength and eventually leads to larger dynamic aperture of the collider. The betatron phase advances from the IP to the sextuples are chosen to eliminate the second order chromatic aberration. )

  4. Higher-Order Spectrum in Understanding Nonlinearity in EEG Rhythms

    PubMed Central

    Pradhan, Cauchy; Jena, Susant K.; Nadar, Sreenivasan R.; Pradhan, N.

    2012-01-01

    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. PMID:22400046

  5. Conceptualizing and Assessing Higher-Order Thinking in Reading

    ERIC Educational Resources Information Center

    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…

  6. Skinner-Rusk unified formalism for higher-order systems

    NASA Astrophysics Data System (ADS)

    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.

  7. Higher-order Dirac solitons in binary waveguide arrays

    SciTech Connect

    Tran, Truong X.; Duong, Dũng C.

    2015-10-15

    We study optical analogues of higher-order Dirac solitons (HODSs) in binary waveguide arrays. Like higher-order solitons obtained from the well-known nonlinear Schrödinger equation governing the pulse propagation in an optical fiber, these HODSs have amplitude profiles which are numerically shown to be periodic over large propagation distances. At the same time, HODSs possess some unique features. Firstly, the period of a HODS depends on its order parameter. Secondly, the discrete nature in binary waveguide arrays imposes the upper limit on the order parameter of HODSs. Thirdly, the order parameter of HODSs can vary continuously in a certain range. - Highlights: • Higher-order Dirac solitons in nonlinear binary waveguide arrays are numerically demonstrated. • Amplitude profiles of higher-order Dirac solitons are periodic during propagation. • The period of higher-order Dirac solitons decreases when the soliton order increases.

  8. Quantifying higher-order correlations in a neuronal pool

    NASA Astrophysics Data System (ADS)

    Montangie, Lisandro; Montani, Fernando

    2015-03-01

    Recent experiments involving a relatively large population of neurons have shown a very significant amount of higher-order correlations. However, little is known of how these affect the integration and firing behavior of a population of neurons beyond the second order statistics. To investigate how higher-order inputs statistics can shape beyond pairwise spike correlations and affect information coding in the brain, we consider a neuronal pool where each neuron fires stochastically. We develop a simple mathematically tractable model that makes it feasible to account for higher-order spike correlations in a neuronal pool with highly interconnected common inputs beyond second order statistics. In our model, correlations between neurons appear from q-Gaussian inputs into threshold neurons. The approach constitutes the natural extension of the Dichotomized Gaussian model, where the inputs to the model are just Gaussian distributed and therefore have no input interactions beyond second order. We obtain an exact analytical expression for the joint distribution of firing, quantifying the degree of higher-order spike correlations, truly emphasizing the functional aspects of higher-order statistics, as we account for beyond second order inputs correlations seen by each neuron within the pool. We determine how higher-order correlations depend on the interaction structure of the input, showing that the joint distribution of firing is skewed as the parameter q increases inducing larger excursions of synchronized spikes. We show how input nonlinearities can shape higher-order correlations and enhance coding performance by neural populations.

  9. Promoting Higher Order Thinking Skills Using Inquiry-Based Learning

    ERIC Educational Resources Information Center

    Madhuri, G. V.; Kantamreddi, V. S. S. N; Prakash Goteti, L. N. S.

    2012-01-01

    Active learning pedagogies play an important role in enhancing higher order cognitive skills among the student community. In this work, a laboratory course for first year engineering chemistry is designed and executed using an inquiry-based learning pedagogical approach. The goal of this module is to promote higher order thinking skills in…

  10. Higher-order theories from the minimal length

    NASA Astrophysics Data System (ADS)

    Dias, M.; Hoff da Silva, J. M.; Scatena, E.

    2016-06-01

    We show that the introduction of a minimal length in the context of noncommutative space-time gives rise (after some considerations) to higher-order theories. We then explicitly demonstrate how these higher-derivative theories appear as a generalization of the standard electromagnetism and general relativity by applying a consistent procedure that modifies the original Maxwell and Einstein-Hilbert actions. In order to set a bound on the minimal length, we compare the deviations from the inverse-square law with the potentials obtained in the higher-order theories and discuss the validity of the results. The introduction of a quantum bound for the minimal length parameter β in the higher-order QED allows us to lower the actual limits on the parameters of higher-derivative gravity by almost half of their order of magnitude.

  11. Higher Order Modeling In the BEM/FEM Hybrid Formulation

    NASA Technical Reports Server (NTRS)

    Fink, Patrick W.; Wilton, Don R.

    2000-01-01

    Hybrid formulations using low order curl-conforming bases to represent the total electric field within a finite element region and low order divergence-conforming bases to represent equivalent electric and magnetic currents on the boundary are well known. However, higher-order divergence and curl-conforming bases have been shown to provide significant benefits in convergence rates and accuracy when employed in strictly integral equation and strictly finite element formulations. In this paper, a hybrid electric field formulation employing higher order bases is presented. The paper addresses benefits and issues associated with using higher order divergence-and curl-conforming bases in the hybrid finite element/boundary element electric field formulation. The method of singularity subtraction may be used to compute the self terms of the boundary integral when the bases are of low order. But this method becomes laborious and requires great care when the divergence conforming bases are of higher order. In order to handle these singularities simply and accurately, a generalized Gaussian quadrature method is employed in which the expansion functions account for the singularity. In preliminary tests of the higher order hybrid formulation, the equivalent electric current induced by scattering of a plane wave from a square dielectric cylinder is examined. Accurate results are obtained using only a two-triangle mesh when the current basis is of order 4 or 5. Additional results are presented comparing the error obtained using higher order bases to that obtained using lower order bases when the number of unknowns is approximately equal. Also, convergence rates obtained with higher order bases are compared to those obtained with lower order bases for selected sample problems.

  12. Application of Mass Lumped Higher Order Finite Elements

    SciTech Connect

    Chen, J.; Strauss, H. R.; Jardin, S. C.; Park, W.; Sugiyama, L. E.; G. Fu; Breslau, J.

    2005-11-01

    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.

  13. Symplectic structures related with higher order variational problems

    NASA Astrophysics Data System (ADS)

    Kijowski, Jerzy; Moreno, Giovanni

    2015-06-01

    In this paper, we derive the symplectic framework for field theories defined by higher order Lagrangians. The construction is based on the symplectic reduction of suitable spaces of iterated jets. The possibility of reducing a higher order system of partial differential equations to a constrained first-order one, the symplectic structures naturally arising in the dynamics of a first-order Lagrangian theory, and the importance of the Poincaré-Cartan form for variational problems, are all well-established facts. However, their adequate combination corresponding to higher order theories is missing in the literature. Here we obtain a consistent and truly finite-dimensional canonical formalism, as well as a higher order version of the Poincaré-Cartan form. In our exposition, the rigorous global proofs of the main results are always accompanied by their local coordinate descriptions, indispensable to work out practical examples.

  14. Predicting perceptual learning from higher-order cortical processing.

    PubMed

    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. PMID:26391126

  15. On higher order geometric and renormalization group flows

    NASA Astrophysics Data System (ADS)

    Prabhu, Kartik; Das, Sanjit; Kar, Sayan

    2011-10-01

    Renormalization group (RG) flows of the bosonic nonlinear σ-model are governed, perturbatively, at different orders of α', by perturbatively evaluated β-functions. In regions where {α'}/{Rc2}≪1 ( {1}/{Rc2} represents the curvature scale), the flow equations at various orders in α' can be thought of as approximating the full, non-perturbative RG flow. On the other hand, taking a different viewpoint, we may consider the above-mentioned RG flow equations as viable geometric flows in their own right, without any reference to the RG aspect. Looked at as purely geometric flows where higher order terms appear, we no longer have the perturbative restrictions (small curvatures). In this paper, we perform our analysis from both these perspectives using specific target manifolds such as S2, H2, unwarped S2×H2 and simple warped products. We analyse and solve the higher order RG flow equations within the appropriate perturbative domains and find the corrections arising due to the inclusion of higher order terms. Such corrections, within the perturbative regime, are shown to be small and they provide an estimate of the error that arises when higher orders are ignored. We also investigate higher order geometric flows on the same manifolds and figure out generic features of geometric evolution, the appearance of singularities and solitons. The aim, in this context, is to demonstrate the role of higher order terms in modifying the flow. One interesting aspect of our analysis is that, separable solutions of the higher order flow equations for simple warped spacetimes (of the kind used in bulk-brane models with a single extra dimension), correspond to constant curvature anti de Sitter (AdS) spacetimes, modulo an overall flow parameter dependent scale factor. The functional form of this scale factor (that we obtain) changes on the inclusion of successive higher order terms in the flow.

  16. A Testing Theory for a Higher-Order Cryptographic Language

    NASA Astrophysics Data System (ADS)

    Koutavas, Vasileios; Hennessy, Matthew

    We study a higher-order concurrent language with cryptographic primitives, for which we develop a sound and complete, first-order testing theory for the preservation of safety properties. Our theory is based on co-inductive set simulations over transitions in a first-order Labelled Transition System. This keeps track of the knowledge of the observer, and treats transmitted higher-order values in a symbolic manner, thus obviating the quantification over functional contexts. Our characterisation provides an attractive proof technique, and we illustrate its usefulness in proofs of equivalence, including cases where bisimulation theory does not apply.

  17. Superposition rules for higher order systems and their applications

    NASA Astrophysics Data System (ADS)

    Cariñena, J. F.; Grabowski, J.; de Lucas, J.

    2012-05-01

    Superposition rules form a class of functions that describe general solutions of systems of first-order ordinary differential equations in terms of generic families of particular solutions and certain constants. In this work, we extend this notion and other related ones to systems of higher order differential equations and analyse their properties. Several results concerning the existence of various types of superposition rules for higher order systems are proved and illustrated with examples extracted from the physics and mathematics literature. In particular, two new superposition rules for the second- and third-order Kummer-Schwarz equations are derived.

  18. Unambiguous formalism for higher order Lagrangian field theories

    NASA Astrophysics Data System (ADS)

    Campos, Cédric M.; de León, Manuel; Martín de Diego, David; Vankerschaver, Joris

    2009-11-01

    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.

  19. On the Evaluation of Higher-Order Science Instructional Objectives

    ERIC Educational Resources Information Center

    Hambleton, Ronald K.; Sheehan, Daniel S.

    1977-01-01

    Advocates the use of a free-sort categorization technique for evaluation of higher-order science instructional objectives. An explanation and demonstration of the use of the evaluation technique with 284 ninth-grade science students is provided. (CP)

  20. Chromatin higher-order structures and gene regulation

    PubMed Central

    Li, Guohong

    2011-01-01

    Genomic DNA in the eukaryotic nucleus is hierarchically packaged by histones into chromatin to fit inside the nucleus. The dynamics of higher-order chromatin compaction play a critical role in transcription and other biological processes inherent to DNA. Many factors, including histone variants, histone modifications, DNA methylation and the binding of non-histone architectural proteins regulate the structure of chromatin. Although the structure of nucleosomes, the fundamental repeating unit of chromatin, is clear, there is still much discussion on the higher-order levels of chromatin structure. In this review, we focus on the recent progress in elucidating the structure of the 30-nm chromatin fiber. We also discuss the structural plasticity/dynamics and epigenetic inheritance of higher-order chromatin and the roles of chromatin higher-order organization in eukaryotic gene regulation. PMID:21342762

  1. Emotion recognition from EEG using higher order crossings.

    PubMed

    Petrantonakis, Panagiotis C; Hadjileontiadis, Leontios J

    2010-03-01

    Electroencephalogram (EEG)-based emotion recognition is a relatively new field in the affective computing area with challenging issues regarding the induction of the emotional states and the extraction of the features in order to achieve optimum classification performance. In this paper, a novel emotion evocation and EEG-based feature extraction technique is presented. In particular, the mirror neuron system concept was adapted to efficiently foster emotion induction by the process of imitation. In addition, higher order crossings (HOC) analysis was employed for the feature extraction scheme and a robust classification method, namely HOC-emotion classifier (HOC-EC), was implemented testing four different classifiers [quadratic discriminant analysis (QDA), k-nearest neighbor, Mahalanobis distance, and support vector machines (SVMs)], in order to accomplish efficient emotion recognition. Through a series of facial expression image projection, EEG data have been collected by 16 healthy subjects using only 3 EEG channels, namely Fp1, Fp2, and a bipolar channel of F3 and F4 positions according to 10-20 system. Two scenarios were examined using EEG data from a single-channel and from combined-channels, respectively. Compared with other feature extraction methods, HOC-EC appears to outperform them, achieving a 62.3% (using QDA) and 83.33% (using SVM) classification accuracy for the single-channel and combined-channel cases, respectively, differentiating among the six basic emotions, i.e., happiness, surprise, anger, fear, disgust, and sadness. As the emotion class-set reduces its dimension, the HOC-EC converges toward maximum classification rate (100% for five or less emotions), justifying the efficiency of the proposed approach. This could facilitate the integration of HOC-EC in human machine interfaces, such as pervasive healthcare systems, enhancing their affective character and providing information about the user's emotional status (e.g., identifying user's emotion

  2. Higher order derivatives of R-Jacobi polynomials

    NASA Astrophysics Data System (ADS)

    Das, Sourav; Swaminathan, A.

    2016-06-01

    In this work, the R-Jacobi polynomials defined on the nonnegative real axis related to F-distribution are considered. Using their Sturm-Liouville system higher order derivatives are constructed. Orthogonality property of these higher ordered R-Jacobi polynomials are obtained besides their normal form, self-adjoint form and hypergeometric representation. Interesting results on the Interpolation formula and Gaussian quadrature formulae are obtained with numerical examples.

  3. The Lagrangian-Hamiltonian formalism for higher order field theories

    NASA Astrophysics Data System (ADS)

    Vitagliano, Luca

    2010-06-01

    We generalize the Lagrangian-Hamiltonian formalism of Skinner and Rusk to higher order field theories on fiber bundles. As a byproduct we solve the long standing problem of defining, in a coordinate free manner, a Hamiltonian formalism for higher order Lagrangian field theories. Namely, our formalism does only depend on the action functional and, therefore, unlike previously proposed ones, is free from any relevant ambiguity.

  4. Feynman rules of higher-order poles in CHY construction

    NASA Astrophysics Data System (ADS)

    Huang, Rijun; Feng, Bo; Luo, Ming-xing; Zhu, Chuan-Jie

    2016-06-01

    In this paper, we generalize the integration rules for scattering equations to situations where higher-order poles are present. We describe the strategy to deduce the Feynman rules of higher-order poles from known analytic results of simple CHY-integrands, and propose the Feynman rules for single double pole and triple pole as well as duplex-double pole and triplex-double pole structures. We demonstrate the validation and strength of these rules by ample non-trivial examples.

  5. Higher Order Lagrange Finite Elements In M3D

    SciTech Connect

    J. Chen; H.R. Strauss; S.C. Jardin; W. Park; L.E. Sugiyama; G. Fu; J. Breslau

    2004-12-17

    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.

  6. Unified formalism for higher order non-autonomous dynamical systems

    NASA Astrophysics Data System (ADS)

    Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso

    2012-03-01

    This work is devoted to giving a geometric framework for describing higher order non-autonomous mechanical systems. The starting point is to extend the Lagrangian-Hamiltonian unified formalism of Skinner and Rusk for these kinds of systems, generalizing previous developments for higher order autonomous mechanical systems and first-order non-autonomous mechanical systems. Then, we use this unified formulation to derive the standard Lagrangian and Hamiltonian formalisms, including the Legendre-Ostrogradsky map and the Euler-Lagrange and the Hamilton equations, both for regular and singular systems. As applications of our model, two examples of regular and singular physical systems are studied.

  7. Higher-order conditioning and the retrosplenial cortex.

    PubMed

    Todd, Travis P; Huszár, Roman; DeAngeli, Nicole E; Bucci, David J

    2016-09-01

    The retrosplenial cortex (RSC) is known to contribute to contextual and spatial learning and memory. This is consistent with its well-established connectivity; the RSC is located at the interface of visuo-spatial association areas and the parahippocampal-hippocampal memory system. However, the RSC also contributes to learning and memory for discrete cues. For example, both permanent lesions and temporary inactivation of the RSC have been shown to impair sensory preconditioning, a form of higher-order conditioning. The purpose of the present experiment was to examine the role of the RSC in a closely related higher-order conditioning paradigm: second-order conditioning. Sham and RSC lesioned rats received first-order conditioning in which one visual stimulus (V1) was paired with footshock and one visual stimulus (V2) was not. Following first-order conditioning, one auditory stimulus (A1) was then paired with V1 and a second auditory stimulus (A2) was paired with V2. Although lesions of the RSC impaired the first-order discrimination, they had no impact on the acquisition of second-order conditioning. Thus, the RSC does not appear necessary for acquisition/expression of second-order fear conditioning. The role of the RSC in higher-order conditioning, as well as a possible dissociation from the hippocampus, is discussed. PMID:27208598

  8. Ability, Breadth, and Parsimony in Computational Models of Higher-Order Cognition

    ERIC Educational Resources Information Center

    Cassimatis, Nicholas L.; Bello, Paul; Langley, Pat

    2008-01-01

    Computational models will play an important role in our understanding of human higher-order cognition. How can a model's contribution to this goal be evaluated? This article argues that three important aspects of a model of higher-order cognition to evaluate are (a) its ability to reason, solve problems, converse, and learn as well as people do;…

  9. Modeling Higher-Order Correlations within Cortical Microcolumns

    PubMed Central

    Köster, Urs; Sohl-Dickstein, Jascha; Gray, Charles M.; Olshausen, Bruno A.

    2014-01-01

    We statistically characterize the population spiking activity obtained from simultaneous recordings of neurons across all layers of a cortical microcolumn. Three types of models are compared: an Ising model which captures pairwise correlations between units, a Restricted Boltzmann Machine (RBM) which allows for modeling of higher-order correlations, and a semi-Restricted Boltzmann Machine which is a combination of Ising and RBM models. Model parameters were estimated in a fast and efficient manner using minimum probability flow, and log likelihoods were compared using annealed importance sampling. The higher-order models reveal localized activity patterns which reflect the laminar organization of neurons within a cortical column. The higher-order models also outperformed the Ising model in log-likelihood: On populations of 20 cells, the RBM had 10% higher log-likelihood (relative to an independent model) than a pairwise model, increasing to 45% gain in a larger network with 100 spatiotemporal elements, consisting of 10 neurons over 10 time steps. We further removed the need to model stimulus-induced correlations by incorporating a peri-stimulus time histogram term, in which case the higher order models continued to perform best. These results demonstrate the importance of higher-order interactions to describe the structure of correlated activity in cortical networks. Boltzmann Machines with hidden units provide a succinct and effective way to capture these dependencies without increasing the difficulty of model estimation and evaluation. PMID:24991969

  10. Optimized higher-order automatic differentiation for the Faddeeva function

    NASA Astrophysics Data System (ADS)

    Charpentier, Isabelle

    2016-08-01

    Considerable research efforts have been directed at implementing the Faddeeva function w(z) and its derivatives with respect to z, but these did not consider the key computing issue of a possible dependence of z on some variable t. The general case is to differentiate the compound function w(z(t)) = w ∘ z(t) with respect to t by applying the chain rule for a first order derivative, or Faà di Bruno's formula for higher-order ones. Higher-order automatic differentiation (HOAD) is an efficient and accurate technique for derivative calculation along scientific computing codes. Although codes are available for w(z) , a special symbolic HOAD is required to compute accurate higher-order derivatives for w ∘ z(t) in an efficient manner. A thorough evaluation is carried out considering a nontrivial case study in optics to support this assertion.

  11. Dynamics and control of higher-order nonholonomic systems

    NASA Astrophysics Data System (ADS)

    Rubio Hervas, Jaime

    A theoretical framework is established for the control of higher-order nonholonomic systems, defined as systems that satisfy higher-order nonintegrable constraints. A model for such systems is developed in terms of differential-algebraic equations defined on a higher-order tangent bundle. A number of control-theoretic properties such as nonintegrability, controllability, and stabilizability are presented. Higher-order nonholonomic systems are shown to be strongly accessible and, under certain conditions, small time locally controllable at any equilibrium. There are important examples of higher-order nonholonomic systems that are asymptotically stabilizable via smooth feedback, including space vehicles with multiple slosh modes and Prismatic-Prismatic-Revolute (PPR) robots moving open liquid containers, as well as an interesting class of systems that do not admit asymptotically stabilizing continuous static or dynamic state feedback. Specific assumptions are introduced to define this class, which includes important examples of robotic systems. A discontinuous nonlinear feedback control algorithm is developed to steer any initial state to the equilibrium at the origin. The applicability of the theoretical development is illustrated through two examples: control of a planar PPR robot manipulator subject to a jerk constraint and control of a point mass moving on a constant torsion curve in a three dimensional space.

  12. LOCAL ANISOTROPY, HIGHER ORDER STATISTICS, AND TURBULENCE SPECTRA

    SciTech Connect

    Matthaeus, W. H.; Wan, M.; Osman, K. T.; Servidio, S.; Carbone, V.; Dmitruk, P.; Oughton, S.

    2012-05-10

    Correlation anisotropy emerges dynamically in magnetohydrodynamics (MHD), producing stronger gradients across the large-scale mean magnetic field than along it. This occurs both globally and locally, and has significant implications in space and astrophysical plasmas, including particle scattering and transport, and theories of turbulence. Properties of local correlation anisotropy are further documented here by showing through numerical experiments that the effect is intensified in more localized estimates of the mean field. The mathematical formulation of this property shows that local anisotropy mixes second-order with higher order correlations. Sensitivity of local statistical estimates to higher order correlations can be understood in connection with the stochastic coordinate system inherent in such formulations. We demonstrate this in specific cases, and illustrate the connection to higher order statistics by showing the sensitivity of local anisotropy to phase randomization, after which the global measure of anisotropy is recovered at all scales of averaging. This establishes that anisotropy of the local structure function is not a measure of anisotropy of the energy spectrum. Evidently, the local enhancement of correlation anisotropy is of substantial fundamental interest and must be understood in terms of higher order correlations, specifically fourth-order and above.

  13. Symplectic representation of higher-order guiding-center theory

    NASA Astrophysics Data System (ADS)

    Brizard, Alain; Tronko, Natalia

    2012-03-01

    Two representations of guiding-center theory are possible depending on whether the guiding-center Poisson bracket (i.e., the symplectic structure) or the Hamiltonian contains higher-order corrections due to the nonuniformity of the magnetic field. By combining the guiding-center parallel hierarchy with the symplectic representation, the guiding-center equations of motion are derived with second-order corrections included in the symplectic structure without the need of carrying out the guiding-center transformation to second order. Guiding-center polarization and magnetization are thus shown to arise naturally from higher-order guiding-center theory within the context of a two-step derivation of nonlinear gyrokinetic theory.footnotetextA. J. Brizard and T. S. Hahm, Rev. Mod. Phys. 79, 421 (2007).

  14. Stable static structures in models with higher-order derivatives

    SciTech Connect

    Bazeia, D.; Lobão, A.S.; Menezes, R.

    2015-09-15

    We investigate the presence of static solutions in generalized models described by a real scalar field in four-dimensional space–time. We study models in which the scalar field engenders higher-order derivatives and spontaneous symmetry breaking, inducing the presence of domain walls. Despite the presence of higher-order derivatives, the models keep to equations of motion second-order differential equations, so we focus on the presence of first-order equations that help us to obtain analytical solutions and investigate linear stability on general grounds. We then illustrate the general results with some specific examples, showing that the domain wall may become compact and that the zero mode may split. Moreover, if the model is further generalized to include k-field behavior, it may contribute to split the static structure itself.

  15. Breaking the symmetry for enhanced higher-order mode delocalization

    NASA Astrophysics Data System (ADS)

    Stutzki, Fabian; Jansen, Florian; Jauregui, Cesar; Limpert, Jens; Tünnermann, Andreas

    2014-03-01

    Large-pitch fibers (LPFs) have enabled the current records for average power, pulse energy and pulse peak power in ultra-fast fiber laser systems. In this paper the working principle of LPFs, which is based on higher-order mode delocalization, is numerically analyzed paying special attention to thermal effects and index mismatch. An enhanced design concept is proposed with a reduced symmetry to improve the delocalization of higher-order modes. This enhanced design has been obtained by transferring the most important characteristics of spiral geometries to a common hexagonal lattice.

  16. Higher order mode laser beam scintillations in oceanic medium

    NASA Astrophysics Data System (ADS)

    Baykal, Yahya

    2016-01-01

    In a horizontal oceanic optical wireless communication link, the scintillation index (the measure for the intensity fluctuations) of the received intensity caused by the oceanic turbulence is formulated and evaluated when the source is a higher order mode laser. Variations in the scintillation index vs. the underwater turbulence parameters, size of the higher order mode laser source, link length, and the wavelength are examined. Underwater turbulence parameters are the ratio that determines the relative strength of temperature and salinity in driving the index fluctuations, the rate of dissipation of the mean squared temperature, the rate of dissipation of the turbulent kinetic energy, and the Kolmogorov microscale length.

  17. Vakonomic Constraints in Higher-Order Classical Field Theory

    NASA Astrophysics Data System (ADS)

    Campos, Cédric M.

    2010-07-01

    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. The result is that we obtain a unique and global intrinsic description of the dynamics. The case of vakonomic constraints is also studied within this formalism.

  18. Higher Order Mode Coupler Heating in Continuous Wave Operation

    NASA Astrophysics Data System (ADS)

    Solyak, N.; Awida, M.; Hocker, A.; Khabibobulline, T.; Lunin, A.

    Electromagnetic heating due to higher order modes (HOM) propagation is particularly a concern for continuous wave (CW) particle accelerator machines. Power on the order of several watts could flow out of the cavity's HOM ports in CW operations. The upgrade of the Linac Coherent Light Source (LCLS-II) at SLAC requires a major modification of the design of the higher order mode (HOM) antenna and feed through of the conventional ILC elliptical 9-cell cavity in order to utilize it for LCLS-II. The HOM antenna is required to bear higher RF losses, while relatively maintaining the coupling level of the higher order modes. In this paper, we present a detailed analysis of the heating expected in the HOM coupler with a thorough thermal quench study in comparison with the conventional ILC design. We discuss also how the heat will be removed from the cavity through RF cables with specially designed cooling straps. Finally, we report on the latest experimental results of cavity testing in vertical and horizontal cryostats.

  19. Numerical modeling of higher order magnetic moments in UXO discrimination

    USGS Publications Warehouse

    Sanchez, V.; Yaoguo, L.; Nabighian, M.N.; Wright, D.L.

    2008-01-01

    The surface magnetic anomaly observed in unexploded ordnance (UXO) clearance is mainly dipolar, and consequently, the dipole is the only magnetic moment regularly recovered in UXO discrimination. The dipole moment contains information about the intensity of magnetization but lacks information about the shape of the target. In contrast, higher order moments, such as quadrupole and octupole, encode asymmetry properties of the magnetization distribution within the buried targets. In order to improve our understanding of magnetization distribution within UXO and non-UXO objects and to show its potential utility in UXO clearance, we present a numerical modeling study of UXO and related metallic objects. The tool for the modeling is a nonlinear integral equation describing magnetization within isolated compact objects of high susceptibility. A solution for magnetization distribution then allows us to compute the magnetic multipole moments of the object, analyze their relationships, and provide a depiction of the anomaly produced by different moments within the object. Our modeling results show the presence of significant higher order moments for more asymmetric objects, and the fields of these higher order moments are well above the noise level of magnetic gradient data. The contribution from higher order moments may provide a practical tool for improved UXO discrimination. ?? 2008 IEEE.

  20. Construction of special eye models for investigation of chromatic and higher-order aberrations of eyes.

    PubMed

    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. PMID:25227016

  1. Higher order matrix differential equations with singular coefficient matrices

    SciTech Connect

    Fragkoulis, V. C.; Kougioumtzoglou, I. A.; Pantelous, A. A.; Pirrotta, A.

    2015-03-10

    In this article, the class of higher order linear matrix differential equations with constant coefficient matrices and stochastic process terms is studied. The coefficient of the highest order is considered to be singular; thus, rendering the response determination of such systems in a straightforward manner a difficult task. In this regard, the notion of the generalized inverse of a singular matrix is used for determining response statistics. Further, an application relevant to engineering dynamics problems is included.

  2. Prominent Higher-Order Contributions to Electronic Recombination

    SciTech Connect

    Beilmann, C.; Mokler, P. H.; Bernitt, S.; Keitel, C. H.; Ullrich, J.; Lopez-Urrutia, J. R. Crespo; Harman, Z.

    2011-09-30

    Intershell higher-order (HO) electronic recombination is reported for highly charged Ar, Fe, and Kr ions, where simultaneous excitation of one K-shell electron and one or two additional L-shell electrons occurs upon resonant capture of a free electron. For the mid-Z region, HO resonance strengths grow unexpectedly strong with decreasing atomic number Z ({proportional_to}Z{sup -4}), such that, for Ar ions the 2nd-order overwhelms the 1st-order resonant recombination considerably. The experimental findings are confirmed by multiconfiguration Dirac-Fock calculations including hitherto neglected excitation pathways.

  3. Higher-order dynamical effects in Coulomb dissociation

    SciTech Connect

    Esbensen, H.; Bertsch, G.F.; Bertulani, C.A.

    1995-08-01

    Coulomb dissociation is a technique commonly used to extract the dipole response of nuclei far from stability. This technique is applicable if the dissociation is dominated by dipole transitions and if first-order perturbation theory is valid. In order to assess the significance of higher-order processes we solve numerically the time evolution of the wave function for a two-body breakup in the Coulomb field from a high Z target. We applied this method to the breakup reactions: {sup 11}Be {yields} {sup 10}Be + n and {sup 11}Li {yields} +2n. The latter is treated as a two-body breakup, using a di-neutron model.

  4. Higher Order Language Competence and Adolescent Mental Health

    ERIC Educational Resources Information Center

    Cohen, Nancy J.; Farnia, Fataneh; Im-Bolter, Nancie

    2013-01-01

    Background: Clinic and community-based epidemiological studies have shown an association between child psychopathology and language impairment. The demands on language for social and academic adjustment shift dramatically during adolescence and the ability to understand the nonliteral meaning in language represented by higher order language…

  5. Computer-Mediated Assessment of Higher-Order Thinking Development

    ERIC Educational Resources Information Center

    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…

  6. Using Higher Order Computer Tasks with Disadvantaged Students.

    ERIC Educational Resources Information Center

    Anderson, Neil

    A pilot program initially designed for a 12-year-old girl with mild to moderate intellectual disabilities in higher order computer tasks was developed for a larger group of students with similar disabilities enrolled in fifth and sixth grades (ages 9-12) at three different schools. An examination of the original pilot study was undertaken to…

  7. Higher-Order Latent Trait Models for Cognitive Diagnosis

    ERIC Educational Resources Information Center

    de la Torre, Jimmy; Douglas, Jeffrey A.

    2004-01-01

    Higher-order latent traits are proposed for specifying the joint distribution of binary attributes in models for cognitive diagnosis. This approach results in a parsimonious model for the joint distribution of a high-dimensional attribute vector that is natural in many situations when specific cognitive information is sought but a less informative…

  8. Constrained variational calculus for higher order classical field theories

    NASA Astrophysics Data System (ADS)

    Campos, Cédric M.; de León, Manuel; Martín de Diego, David

    2010-11-01

    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.

  9. Higher order microfibre modes for dielectric particle trapping and propulsion.

    PubMed

    Maimaiti, Aili; Truong, Viet Giang; Sergides, Marios; Gusachenko, Ivan; Nic Chormaic, Síle

    2015-01-01

    Optical manipulation in the vicinity of optical micro- and nanofibres has shown potential across several fields in recent years, including microparticle control, and cold atom probing and trapping. To date, most work has focussed on the propagation of the fundamental mode through the fibre. However, along the maximum mode intensity axis, higher order modes have a longer evanescent field extension and larger field amplitude at the fibre waist compared to the fundamental mode, opening up new possibilities for optical manipulation and particle trapping. We demonstrate a microfibre/optical tweezers compact system for trapping and propelling dielectric particles based on the excitation of the first group of higher order modes at the fibre waist. Speed enhancement of polystyrene particle propulsion was observed for the higher order modes compared to the fundamental mode for particles ranging from 1 μm to 5 μm in diameter. The optical propelling velocity of a single, 3 μm polystyrene particle was found to be 8 times faster under the higher order mode than the fundamental mode field for a waist power of 25 mW. Experimental data are supported by theoretical calculations. This work can be extended to trapping and manipulation of laser-cooled atoms with potential for quantum networks. PMID:25766925

  10. Higher-order structure of rRNA

    NASA Technical Reports Server (NTRS)

    Gutell, R. R.; Woese, C. R.

    1986-01-01

    A comparative search for phylogenetically covarying basepair replacements within potential helices has been the only reliable method to determine the correct secondary structure of the 3 rRNAs, 5S, 16S, and 23S. The analysis of 16S from a wide phylogenetic spectrum, that includes various branches of the eubacteria, archaebacteria, eucaryotes, in addition to the mitochondria and chloroplast, is beginning to reveal the constraints on the secondary structures of these rRNAs. Based on the success of this analysis, and the assumption that higher order structure will also be phylogenetically conserved, a comparative search was initiated for positions that show co-variation not involved in secondary structure helices. From a list of potential higher order interactions within 16S rRNA, two higher-order interactions are presented. The first of these interactions involves positions 570 and 866. Based on the extent of phylogenetic covariation between these positions while maintaining Watson-Crick pairing, this higher-order interaction is considered proven. The other interaction involves a minimum of six positions between the 1400 and 1500 regions of the 16S rRNA. Although these patterns of covariation are not as striking as the 570/866 interaction, the fact that they all exist in an anti-parallel fashion and that experimental methods previously implicated these two regions of the molecule in tRNA function suggests that these interactions be given serious consideration.

  11. Building Higher-Order Markov Chain Models with EXCEL

    ERIC Educational Resources Information Center

    Ching, Wai-Ki; Fung, Eric S.; Ng, Michael K.

    2004-01-01

    Categorical data sequences occur in many applications such as forecasting, data mining and bioinformatics. In this note, we present higher-order Markov chain models for modelling categorical data sequences with an efficient algorithm for solving the model parameters. The algorithm can be implemented easily in a Microsoft EXCEL worksheet. We give a…

  12. Using Database Projects To Promote Higher-Order Thinking Skills.

    ERIC Educational Resources Information Center

    Lytle, Cora

    1999-01-01

    Explains how the process of creating a database provides opportunities for business instructors to use teaching strategies that promote higher-order thinking skills. Describes a project at a school of business in which each student must build an original database and apply functions of tables, queries, forms, and reports. (JOW)

  13. Higher order microfibre modes for dielectric particle trapping and propulsion

    PubMed Central

    Maimaiti, Aili; Truong, Viet Giang; Sergides, Marios; Gusachenko, Ivan; Nic Chormaic, Síle

    2015-01-01

    Optical manipulation in the vicinity of optical micro- and nanofibres has shown potential across several fields in recent years, including microparticle control, and cold atom probing and trapping. To date, most work has focussed on the propagation of the fundamental mode through the fibre. However, along the maximum mode intensity axis, higher order modes have a longer evanescent field extension and larger field amplitude at the fibre waist compared to the fundamental mode, opening up new possibilities for optical manipulation and particle trapping. We demonstrate a microfibre/optical tweezers compact system for trapping and propelling dielectric particles based on the excitation of the first group of higher order modes at the fibre waist. Speed enhancement of polystyrene particle propulsion was observed for the higher order modes compared to the fundamental mode for particles ranging from 1 μm to 5 μm in diameter. The optical propelling velocity of a single, 3 μm polystyrene particle was found to be 8 times faster under the higher order mode than the fundamental mode field for a waist power of 25 mW. Experimental data are supported by theoretical calculations. This work can be extended to trapping and manipulation of laser-cooled atoms with potential for quantum networks. PMID:25766925

  14. Assessing the Influence of Portfolios on Higher Order Thinking Skills.

    ERIC Educational Resources Information Center

    Seiter, David M.

    How the use of portfolios in the classroom will influence the higher order thinking skills is the main focus of this project. The introduction of portfolios as assessment tools is rather new to educational research, but does offer a legitimate area for serious study. Portfolios when used by students can offer them not only a way to showcase their…

  15. Multiple-Try Feedback and Higher-Order Learning Outcomes

    ERIC Educational Resources Information Center

    Clariana, Roy B.; Koul, Ravinder

    2005-01-01

    Although feedback is an important component of computer-based instruction (CBI), the effects of feedback on higher-order learning outcomes are not well understood. Several meta-analyses provide two rules of thumb: any feedback is better than no feedback and feedback with more information is better than feedback with less information. …

  16. Developing Higher-Order Thinking Skills through WebQuests

    ERIC Educational Resources Information Center

    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.…

  17. Fostering Higher-Order Thinking in Science Class: Teachers' Reflections

    ERIC Educational Resources Information Center

    Barak, Moshe; Shakhman, Larisa

    2008-01-01

    The study reported in this article aimed at exploring what teachers know and do about fostering higher-order thinking skills in teaching science, and how they see themselves involved in achieving this end. Data were collected through semi-structured interviews with 11 teachers experienced in teaching high school physics, which is considered a…

  18. Using Higher-Order Skills in American History.

    ERIC Educational Resources Information Center

    Litogot, Sandra A.

    1991-01-01

    Provides a six-part lesson plan for use in secondary U.S. history classes. Illustrates the development of higher-order reading, writing, and thinking skills in assignments and projects dealing with the history of westward expansion. Specific skills addressed are comparison, contrast, prediction, and evaluation. Recommends cooperative learning…

  19. Higher-order ionospheric error at Arecibo, Millstone, and Jicamarca

    NASA Astrophysics Data System (ADS)

    Matteo, N. A.; Morton, Y. T.

    2010-12-01

    The ionosphere is a dominant source of Global Positioning System receiver range measurement error. Although dual-frequency receivers can eliminate the first-order ionospheric error, most second- and third-order errors remain in the range measurements. Higher-order ionospheric error is a function of both electron density distribution and the magnetic field vector along the GPS signal propagation path. This paper expands previous efforts by combining incoherent scatter radar (ISR) electron density measurements, the International Reference Ionosphere model, exponential decay extensions of electron densities, the International Geomagnetic Reference Field, and total electron content maps to compute higher-order error at ISRs in Arecibo, Puerto Rico; Jicamarca, Peru; and Millstone Hill, Massachusetts. Diurnal patterns, dependency on signal direction, seasonal variation, and geomagnetic activity dependency are analyzed. Higher-order error is largest at Arecibo with code phase maxima circa 7 cm for low-elevation southern signals. The maximum variation of the error over all angles of arrival is circa 8 cm.

  20. Speckle reduction via higher order total variation approach.

    PubMed

    Wensen Feng; Hong Lei; Yang Gao

    2014-04-01

    Multiplicative noise (also known as speckle) reduction is a prerequisite for many image-processing tasks in coherent imaging systems, such as the synthetic aperture radar. One approach extensively used in this area is based on total variation (TV) regularization, which can recover significantly sharp edges of an image, but suffers from the staircase-like artifacts. In order to overcome the undesirable deficiency, we propose two novel models for removing multiplicative noise based on total generalized variation (TGV) penalty. The TGV regularization has been mathematically proven to be able to eliminate the staircasing artifacts by being aware of higher order smoothness. Furthermore, an efficient algorithm is developed for solving the TGV-based optimization problems. Numerical experiments demonstrate that our proposed methods achieve state-of-the-art results, both visually and quantitatively. In particular, when the image has some higher order smoothness, our methods outperform the TV-based algorithms. PMID:24808350

  1. Higher-order structure of Saccharomyces cerevisiae chromatin

    SciTech Connect

    Lowary, P.T.; Widom, J. )

    1989-11-01

    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.

  2. Higher order corrections in minimal supergravity models of inflation

    SciTech Connect

    Ferrara, Sergio; Kallosh, Renata; Linde, Andrei; Porrati, Massimo E-mail: kallosh@stanford.edu E-mail: massimo.porrati@nyu.edu

    2013-11-01

    We study higher order corrections in new minimal supergravity models of a single scalar field inflation. The gauging in these models leads to a massive vector multiplet and the D-term potential for the inflaton field with a coupling g{sup 2} ∼ 10{sup −10}. In the de-Higgsed phase with vanishing g{sup 2}, the chiral and vector multiplets are non-interacting, and the potential vanishes. We present generic manifestly supersymmetric higher order corrections for these models. In particular, for a supersymmetric gravity model −R+R{sup 2} we derive manifestly supersymmetric corrections corresponding to R{sup n}. The dual version corresponds to a standard supergravity model with a single scalar and a massive vector. It includes, in addition, higher Maxwell curvature/scalar interaction terms of the Born-Infeld type and a modified D-term scalar field potential. We use the dual version of the model to argue that higher order corrections do not affect the last 60 e-foldings of inflation; for example the ξR{sup 4} correction is irrelevant as long as ξ < 10{sup 24}.

  3. Synchronous firing and higher-order interactions in neuron pool.

    PubMed

    Amari, Shun-Ichi; Nakahara, Hiroyuki; Wu, Si; Sakai, Yutaka

    2003-01-01

    The stochastic mechanism of synchronous firing in a population of neurons is studied from the point of view of information geometry. Higher-order interactions of neurons, which cannot be reduced to pairwise correlations, are proved to exist in synchronous firing. In a neuron pool where each neuron fires stochastically, the probability distribution q(r) of the activity r, which is the fraction of firing neurons in the pool, is studied. When q(r) has a widespread distribution, in particular, when q(r) has two peaks, the neurons fire synchronously at one time and are quiescent at other times. The mechanism of generating such a probability distribution is interesting because the activity r is concentrated on its mean value when each neuron fires independently, because of the law of large numbers. Even when pairwise interactions, or third-order interactions, exist, the concentration is not resolved. This shows that higher-order interactions are necessary to generate widespread activity distributions. We analyze a simple model in which neurons receive common overlapping inputs and prove that such a model can have a widespread distribution of activity, generating higher-order stochastic interactions. PMID:12590822

  4. Higher order correlation beams in atmosphere under strong turbulence conditions.

    PubMed

    Avetisyan, H; Monken, C H

    2016-02-01

    Higher order correlation beams, that is, two-photon beams obtained from the process of spontaneous parametric down-conversion pumped by Hermite-Gauss or Laguerre-Gauss beams of any order, can be used to encode information in many modes, opening the possibility of quantum communication with large alphabets. In this paper we calculate, analytically, the fourth-order correlation function for the Hermite-Gauss and Laguerre-Gauss coherent and partially coherent correlation beams propagating through a strong turbulent medium. We show that fourth-order correlation functions for correlation beams have, under certain conditions, expressions similar to those of intensities of classical beams and are degraded by turbulence in a similar way as the classical beams. Our results can be useful in establishing limits for the use of two-photon beams in quantum communications with larger alphabets under atmospheric turbulence. PMID:26906808

  5. Lipkin method of particle-number restoration to higher orders

    NASA Astrophysics Data System (ADS)

    Wang, X. B.; Dobaczewski, J.; Kortelainen, M.; Yu, L. F.; Stoitsov, M. V.

    2014-07-01

    Background: On the mean-field level, pairing correlations are incorporated through the Bogoliubov-Valatin transformation, whereby the particle degrees of freedom are replaced by quasiparticles. This approach leads to a spontaneous breaking of the particle-number symmetry and mixing of states with different particle numbers. In order to restore the particle number, various methods have been employed, which are based on projection approaches before or after variation. Approximate variation-after-projection (VAP) schemes, utilizing the Lipkin method, have mostly been used within the Lipkin-Nogami prescription. Purpose: Without employing the Lipkin-Nogami prescription, and using, instead, states rotated in the gauge space, we derive the Lipkin method of particle-number restoration up to sixth order and we test the convergence and accuracy of the obtained expansion. Methods: We perform self-consistent calculations using the higher-order Lipkin method to restore the particle-number symmetry in the framework of superfluid nuclear energy-density functional theory. We also apply the Lipkin method to a schematic exactly solvable two-level pairing model. Results: Calculations performed in open-shell tin and lead isotopes show that the Lipkin method converges at fourth order and satisfactorily reproduces the VAP ground-state energies and energy kernels. Near closed shells, the higher-order Lipkin method cannot be applied because of a nonanalytic kink in the ground-state energies as a function of the particle number. Conclusions: In open-shell nuclei, the higher-order Lipkin method provides a good approximation to the exact VAP energies. The method is computationally inexpensive, making it particularly suitable, for example, for future optimizations of the nuclear energy density functionals and simultaneous restoration of different symmetries.

  6. A higher order theory of laminated composite cylindrical shells

    NASA Technical Reports Server (NTRS)

    Krishna Murthy, A. V.; Reddy, T. S. R.

    1986-01-01

    A new higher order theory has been proposed for the analysis of composite cylindrical shells. The formulation allows for arbitrary variation of inplane displacements. Governing equations are presented in the form of a hierarchy of sets of partial differential equations. Each set describes the shell behavior to a certain degree of approximation. The natural frequencies of simply-supported isotropic and laminated shells and stresses in a ring loaded composite shell have been determined to various orders of approximation and compared with three dimensional solutions. These numerical studies indicate the improvements achievable in estimating the natural frequencies and the interlaminar shear stresses in laminated composite cylinders.

  7. Algorithmic and Experimental Computation of Higher-Order Safe Primes

    NASA Astrophysics Data System (ADS)

    Díaz, R. Durán; Masqué, J. Muñoz

    2008-09-01

    This paper deals with a class of special primes called safe primes. In the regular definition, an odd prime p is safe if, at least, one of (p±1)/2 is prime. Safe primes have been recommended as factors of RSA moduli. In this paper, the concept of safe primes is extended to higher-order safe primes, and an explicit formula to compute the density of this class of primes in the set of the integers is supplied. Finally, explicit conditions are provided permitting the algorithmic computation of safe primes of arbitrary order. Some experimental results are provided as well.

  8. Sandia Higher Order Elements (SHOE) v 0.5 alpha

    SciTech Connect

    2013-09-24

    SHOE is research code for characterizing and visualizing higher-order finite elements; it contains a framework for defining classes of interpolation techniques and element shapes; methods for interpolating triangular, quadrilateral, tetrahedral, and hexahedral cells using Lagrange and Legendre polynomial bases of arbitrary order; methods to decompose each element into domains of constant gradient flow (using a polynomial solver to identify critical points); and an isocontouring technique that uses this decomposition to guarantee topological correctness. Please note that this is an alpha release of research software and that some time has passed since it was actively developed; build- and run-time issues likely exist.

  9. Higher-order polarization singularitites in tailored vector beams

    NASA Astrophysics Data System (ADS)

    Otte, E.; Alpmann, C.; Denz, C.

    2016-07-01

    Higher-order polarization singularities embedded in tailored vector beams are introduced and experimentally realized. As holographic modulation allows to define order and location of any vectorial singularity, the surrounding vector field can be dynamically shaped. We demonstrate light fields associated with flowers or spider webs due to regular and even irregular patterns of the orientation of polarization ellipses. Beyond that, not yet investigated hybrid structures are introduced that allow generating networks of flowers and webs in very close vicinity. Our results pave the way to applications of singular optics in spatially extended, optimized optical tweezing and high-resolution imaging.

  10. Sandia Higher Order Elements (SHOE) v 0.5 alpha

    Energy Science and Technology Software Center (ESTSC)

    2013-09-24

    SHOE is research code for characterizing and visualizing higher-order finite elements; it contains a framework for defining classes of interpolation techniques and element shapes; methods for interpolating triangular, quadrilateral, tetrahedral, and hexahedral cells using Lagrange and Legendre polynomial bases of arbitrary order; methods to decompose each element into domains of constant gradient flow (using a polynomial solver to identify critical points); and an isocontouring technique that uses this decomposition to guarantee topological correctness. Please notemore » that this is an alpha release of research software and that some time has passed since it was actively developed; build- and run-time issues likely exist.« less

  11. Analytical formulas for gravitational lensing: Higher order calculation

    SciTech Connect

    Amore, Paolo; Arceo, Santiago; Fernandez, Francisco M.

    2006-10-15

    We extend to higher order a recently published method for calculating the deflection angle of light in a general static and spherically symmetric metric. We have tested our method on the metric of Schwarzschild and Reissner-Nordstroem black holes, on the metric of a charged black hole coupled to Born-Infeld electrodynamics and on the metric of Weyl gravity. Since our method is geometrically convergent, as proved in our previous work, our analytical formulas obtained working to fourth order are sufficient to reach errors of few percents even in proximity of the photon sphere.

  12. Stabilization with target oriented control for higher order difference equations

    NASA Astrophysics Data System (ADS)

    Braverman, Elena; Franco, Daniel

    2015-06-01

    For a physical or biological model whose dynamics is described by a higher order difference equation un+1 = f (un ,un-1 , … ,u n - k + 1), we propose a version of a target oriented control un+1 = cT + (1 - c) f (un ,un-1 , … ,u n - k + 1), with T ≥ 0, c ∈ [ 0 , 1). In ecological systems, the method incorporates harvesting and recruitment and for a wide class of f, allows to stabilize (locally or globally) a fixed point of f. If a point which is not a fixed point of f has to be stabilized, the target oriented control is an appropriate method for achieving this goal. As a particular case, we consider pest control applied to pest populations with delayed density-dependence. This corresponds to a proportional feedback method, which includes harvesting only, for higher order equations.

  13. Spatial complexity of solutions of higher order partial differential equations

    NASA Astrophysics Data System (ADS)

    Kukavica, Igor

    2004-03-01

    We address spatial oscillation properties of solutions of higher order parabolic partial differential equations. In the case of the Kuramoto-Sivashinsky equation ut + uxxxx + uxx + u ux = 0, we prove that for solutions u on the global attractor, the quantity card {x epsi [0, L]:u(x, t) = lgr}, where L > 0 is the spatial period, can be bounded by a polynomial function of L for all \\lambda\\in{\\Bbb R} . A similar property is proven for a general higher order partial differential equation u_t+(-1)^{s}\\partial_x^{2s}u+ \\sum_{k=0}^{2s-1}v_k(x,t)\\partial_x^k u =0 .

  14. High Precision Superconducting Cavity Diagnostics With Higher Order Mode Measurements

    SciTech Connect

    Molloy, S.; Frisch, J.; McCormick, D.; May, J.; Ross, M.; Smith, T.; Baboi, N.; Hensler, O.; Petrosian, L.; Napoly, O.; Paparella, R.C.; Simon, C.; Eddy, N.; Nagaitsev, S.; Wendt, M.; /Fermilab

    2007-02-12

    Experiments at the FLASH facility at DESY have demonstrated that the higher order modes induced in superconducting cavities can be used to provide a variety of beam and cavity diagnostics. The axes of the modes can be determined from the beam orbit that produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used to obtain high resolution beam position information, and the phase of the monopole modes to measure the beam phase relative to the accelerator rf. For most superconducting accelerators, the existing higher order mode couplers provide the necessary signals, and the downmix and digitizing electronics are straightforward, similar to those for a conventional beam position monitor.

  15. Promoting higher order thinking skills using inquiry-based learning

    NASA Astrophysics Data System (ADS)

    Madhuri, G. V.; S. S. N Kantamreddi, V.; Goteti, L. N. S. Prakash

    2012-05-01

    Active learning pedagogies play an important role in enhancing higher order cognitive skills among the student community. In this work, a laboratory course for first year engineering chemistry is designed and executed using an inquiry-based learning pedagogical approach. The goal of this module is to promote higher order thinking skills in chemistry. Laboratory exercises are designed based on Bloom's taxonomy and a just-in-time facilitation approach is used. A pre-laboratory discussion outlining the theory of the experiment and its relevance is carried out to enable the students to analyse real-life problems. The performance of the students is assessed based on their ability to perform the experiment, design new experiments and correlate practical utility of the course module with real life. The novelty of the present approach lies in the fact that the learning outcomes of the existing experiments are achieved through establishing a relationship with real-world problems.

  16. Higher order mode excitations in gyro-amplifiers

    NASA Astrophysics Data System (ADS)

    Nguyen, K. T.; Calame, J. P.; Danly, B. G.; Levush, B.; Garven, M.; Antonsen, T.

    2001-05-01

    In gyro-devices, a nonlinear output taper is often employed as the transition from the near cutoff radius of the interaction circuit to a much larger output waveguide. The tapers are usually designed to avoid passive mode conversion, and thus do not consider the effect of a bunched beam. However, recent simulations with the self-consistent MAGY code [Botton et al., IEEE Trans. Plasma Sci. 26, 882 (1998)] indicate that higher order mode interactions with the bunched electron beam can substantially compromise the mode purity of the rf output. The interaction in the taper region is traveling wave in nature, and is strongly dependent on the residual beam bunching characteristics resulting from the upstream operating mode interaction. An experiment has been performed to quantify the rf output mode content from a Ka-band gyroklystron. The agreement between salient theoretical and measured rf output characteristics confirms the existence of higher order mode excitation in output tapers as predicted by theory.

  17. Validating variational principle for higher order theory of gravity

    NASA Astrophysics Data System (ADS)

    Ruz, Soumendranath; Sarkar, Kaushik; Sk, Nayem; Sanyal, Abhik Kumar

    2015-06-01

    Metric variation of higher order theory of gravity requires fixing of the Ricci scalar in addition to the metric tensor at the boundary. Fixing Ricci scalar at the boundary implies that the classical solutions are fixed once and forever to the de Sitter or anti-de Sitter (dS/AdS) solutions. Here, we justify such requirement from the standpoint of Noether symmetry.

  18. Higher-order effects in inclusive electron-nucleus scattering.

    SciTech Connect

    Benhar, O.; Fabrocini, A.; Fantoni, S.; Pandharipande, V. R.; Pieper, S. C.; Sick, I.; Physics; INFIN; Univ. of Pisa; SISSA; Univ. of Illinois; SISSA; Univ. Basel

    1995-10-05

    Higher order corrections in the theory of inclusive scattering of high energy electrons by nuclear matter are studied. They involve at least three nucleons, and are due to: (i) the correlations among the spectator nucleons in matter, and (ii) the Pauli blocking of the scattering of the struck nucleon by a spectator nucleon. Their effect on the cross sections is found to be much smaller than those of the two-nucleon correlation hole and of color transparency.

  19. A higher-order Robert-Asselin type time filter

    NASA Astrophysics Data System (ADS)

    Li, Yong; Trenchea, Catalin

    2014-02-01

    The Robert-Asselin (RA) time filter combined with leapfrog scheme is widely used in numerical models of weather and climate. It successfully suppresses the spurious computational mode associated with the leapfrog method, but it also weakly dampens the physical mode and degrades the numerical accuracy. The Robert-Asselin-Williams (RAW) time filter is a modification of the RA filter that reduces the undesired numerical damping of RA filter and increases the accuracy. We propose a higher-order Robert-Asselin (hoRA) type time filter which effectively suppresses the computational modes and achieves third-order accuracy with the same storage requirement as RAW filter. Like RA and RAW filters, the hoRA filter is non-intrusive, and so it would be easily implementable. The leapfrog scheme with hoRA filter is almost as accurate, stable and efficient as the intrusive third-order Adams-Bashforth (AB3) method.

  20. Higher-order nonlinear effects in a Josephson parametric amplifier

    NASA Astrophysics Data System (ADS)

    Kochetov, Bogdan A.; Fedorov, Arkady

    2015-12-01

    Nonlinearity of the current-phase relationship of a Josephson junction is the key resource for a Josephson parametric amplifier (JPA) as well as for a Josephson traveling-wave parametric amplifier, the only devices in which the quantum limit for added noise has so far been approached at microwave frequencies. A standard approach to describe JPA takes into account only the lowest order (cubic) nonlinearity resulting in a Duffing-like oscillator equation of motion or in a Kerr-type nonlinearity term in the Hamiltonian. In this paper we derive the quantum expression for the gain of JPA including all orders of the Josephson junction nonlinearity in the linear response regime. We then analyze gain saturation effect for stronger signals within a semiclassical approach. Our results reveal nonlinear effects of higher orders and their implications for operation of a JPA.

  1. Higher-order ionosphere modeling for CODE's next reprocessing activities

    NASA Astrophysics Data System (ADS)

    Lutz, S.; Schaer, S.; Meindl, M.; Dach, R.; Steigenberger, P.

    2009-12-01

    CODE (the Center for Orbit Determination in Europe) is a joint venture between the Astronomical Institute of the University of Bern (AIUB, Bern, Switzerland), the Federal Office of Topography (swisstopo, Wabern, Switzerland), the Federal Agency for Cartography and Geodesy (BKG, Frankfurt am Main, Germany), and the Institut für Astronomische und Phsyikalische Geodäsie of the Technische Universität München (IAPG/TUM, Munich, Germany). It acts as one of the global analysis centers of the International GNSS Service (IGS) and participates in the first IGS reprocessing campaign, a full reanalysis of GPS data collected since 1994. For a future reanalyis of the IGS data it is planned to consider not only first-order but also higher-order ionosphere terms in the space geodetic observations. There are several works (e.g. Fritsche et al. 2005), which showed a significant and systematic influence of these effects on the analysis results. The development version of the Bernese Software used at CODE is expanded by the ability to assign additional (scaling) parameters to each considered higher-order ionosphere term. By this, each correction term can be switched on and off on normal-equation level and, moreover, the significance of each correction term may be verified on observation level for different ionosphere conditions.

  2. Orchestration of Molecular Information through Higher Order Chemical Recognition

    NASA Astrophysics Data System (ADS)

    Frezza, Brian M.

    Broadly defined, higher order chemical recognition is the process whereby discrete chemical building blocks capable of specifically binding to cognate moieties are covalently linked into oligomeric chains. These chains, or sequences, are then able to recognize and bind to their cognate sequences with a high degree of cooperativity. Principally speaking, DNA and RNA are the most readily obtained examples of this chemical phenomenon, and function via Watson-Crick cognate pairing: guanine pairs with cytosine and adenine with thymine (DNA) or uracil (RNA), in an anti-parallel manner. While the theoretical principles, techniques, and equations derived herein apply generally to any higher-order chemical recognition system, in practice we utilize DNA oligomers as a model-building material to experimentally investigate and validate our hypotheses. Historically, general purpose information processing has been a task limited to semiconductor electronics. Molecular computing on the other hand has been limited to ad hoc approaches designed to solve highly specific and unique computation problems, often involving components or techniques that cannot be applied generally in a manner suitable for precise and predictable engineering. Herein, we provide a fundamental framework for harnessing high-order recognition in a modular and programmable fashion to synthesize molecular information process networks of arbitrary construction and complexity. This document provides a solid foundation for routinely embedding computational capability into chemical and biological systems where semiconductor electronics are unsuitable for practical application.

  3. Technical decision making with higher order structure data: higher order structure characterization during protein therapeutic candidate screening.

    PubMed

    Jiang, Yijia; Li, Cynthia; Li, Jenny; Gabrielson, John P; Wen, Jie

    2015-04-01

    Protein therapeutics differ considerably from small molecule drugs because of the presence of higher order structure (HOS), post-translational modifications, inherent molecular heterogeneity, and unique stability profiles. At early stages of development, multiple molecular candidates are often produced for the same biological target. In order to select the most promising molecule for further development, studies are carried out to compare and rank order the candidates in terms of their manufacturability, purity, and stability profiles. This note reports a case study on the use of selected HOS characterization methods for candidate selection and the role of HOS data in identifying potential challenges that may be avoided by selecting the optimal molecular entity for continued development. PMID:25716705

  4. Higher-Order Theory for Functionally Graded Materials

    NASA Technical Reports Server (NTRS)

    Aboudi, Jacob; Pindera, Marek-Jerzy; Arnold, Steven M.

    1999-01-01

    This paper presents the full generalization of the Cartesian coordinate-based higher-order theory for functionally graded materials developed by the authors during the past several years. This theory circumvents the problematic use of the standard micromechanical approach, based on the concept of a representative volume element, commonly employed in the analysis of functionally graded composites by explicitly coupling the local (microstructural) and global (macrostructural) responses. The theoretical framework is based on volumetric averaging of the various field quantities, together with imposition of boundary and interfacial conditions in an average sense between the subvolumes used to characterize the composite's functionally graded microstructure. The generalization outlined herein involves extension of the theoretical framework to enable the analysis of materials characterized by spatially variable microstructures in three directions. Specialization of the generalized theoretical framework to previously published versions of the higher-order theory for materials functionally graded in one and two directions is demonstrated. In the applications part of the paper we summarize the major findings obtained with the one-directional and two-directional versions of the higher-order theory. The results illustrate both the fundamental issues related to the influence of microstructure on microscopic and macroscopic quantities governing the response of composites and the technologically important applications. A major issue addressed herein is the applicability of the classical homogenization schemes in the analysis of functionally graded materials. The technologically important applications illustrate the utility of functionally graded microstructures in tailoring the response of structural components in a variety of applications involving uniform and gradient thermomechanical loading.

  5. Higher order mode damping in an ALS test cavity

    SciTech Connect

    Jacob, A.F.; Lamberston, G.R. ); Barry, W. )

    1990-06-01

    The higher order mode attenuation scheme proposed for the Advanced Light Source accelerating cavities consists of two broad-band dampers placed 90{degrees} apart on the outer edge. In order to assess the damping efficiency a test assembly was built. The HOM damping was obtained by comparing the peak values of the transmission through the cavity for both the damped and the undamped case. Because of the high number of modes and frequency shifts due to the damping gear, the damping was assessed statistically, by averaging over several modes. In the frequency range from 1.5 to 5.5 GHz, average damping greater than 100 was obtained. 1 ref., 6 figs.

  6. Polymer quantization, stability and higher-order time derivative terms

    NASA Astrophysics Data System (ADS)

    Cumsille, Patricio; Reyes, Carlos M.; Ossandon, Sebastian; Reyes, Camilo

    2016-03-01

    The possibility that fundamental discreteness implicit in a quantum gravity theory may act as a natural regulator for ultraviolet singularities arising in quantum field theory has been intensively studied. Here, along the same expectations, we investigate whether a nonstandard representation called polymer representation can smooth away the large amount of negative energy that afflicts the Hamiltonians of higher-order time derivative theories, rendering the theory unstable when interactions come into play. We focus on the fourth-order Pais-Uhlenbeck model which can be reexpressed as the sum of two decoupled harmonic oscillators one producing positive energy and the other negative energy. As expected, the Schrödinger quantization of such model leads to the stability problem or to negative norm states called ghosts. Within the framework of polymer quantization we show the existence of new regions where the Hamiltonian can be defined well bounded from below.

  7. Higher-order automatic differentiation of mathematical functions

    NASA Astrophysics Data System (ADS)

    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.

  8. Introduction to Higher Order Spatial Statistics in Cosmology

    NASA Astrophysics Data System (ADS)

    Szapudi, I.

    Higher order spatial statistics characterize non-Gaussian aspects of random fields, which are ubiquitous in cosmology: from the cosmic microwave background (CMB) to the large-scale structure (LSS) of the universe. These random fields are rich in their properties; they can be continuous or discrete; can have one through three, or even more dimensions; their degree of non- Gaussianity ranges from tiny to significant. Yet, there are several techniques and ideas, which are applicable to virtually all cosmological random fields, be it Lyman-a forests, LSS, or CMB.

  9. Higher order software - A methodology for defining software

    NASA Technical Reports Server (NTRS)

    Hamilton, M.; Zeldin, S.

    1976-01-01

    Higher order software (HOS) is concerned only with computable functions and relationships. The HOS methodology can be used for the definition of software for multiprogrammed, multiprocessor, or multicomputer systems. A description of HOS methodology is presented, giving attention to questions of formulation, interface correctness, specification language principles, and HOS analyzers. Aspects of system design are considered, and details of software management are discussed. Attention is given to modularity as defined by HOS, frozen module management, the assembly control supervisor, and aspects of reliability and efficiency.

  10. High Precision SC Cavity alignment Measurements with Higher Order Modes

    SciTech Connect

    Molloy, Stephen; Frisch, Josef; Hendrickson, Linda; McCormick, Douglas; May, Justin; Ross, Marc; Smith, Tonee; Eddy, Nathan; Nagaitsev, Sergei; Baboi, Nicoleta; Hensler, Olaf; Petrosyan, Lyudvig; Napoly, Olivier; Paparella, Rita; Simon, Claire; /DSM, DAPNIA, Saclay

    2007-06-14

    Experiments at the FLASH linac at DESY have demonstrated that the higher order modes (HOMs) induced in superconducting cavities can be used to provide a variety of beam and cavity diagnostics. The centers of the cavities can be determined from the beam orbit which produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used as a high resolution beam position monitor. For most superconducting accelerators, the existing HOM couplers provide the necessary signals, and the downmix and digitizing electronics are straightforward, similar to those for a conventional BPM.

  11. Tight focusing of higher orders Laguerre-Gaussian modes

    NASA Astrophysics Data System (ADS)

    Savelyev, Dmitry A.; Khonina, Svetlana N.; Golub, Ilya

    2016-04-01

    The spatial redistribution of the contribution of different electric field components provides a decrease in the size of the central focal spot for higher orders Laguerre-Gaussian modes. It was shown that when sharply focusing laser beams with vortex or special binary phase plate, a sub-wavelength light localization of separate vector field components is possible for any polarization type. This fact should be considered for the interaction of laser radiation with materials selectively sensitive to lateral and longitudinal components of the electromagnetic field.

  12. Higher Order Mode Properties of Superconducting Two-Spoke Cavities

    SciTech Connect

    Hopper, C. S.; Delayen, J. R.; Olave, R. G.

    2011-07-01

    Multi-Spoke cavities lack the cylindrical symmetry that many other cavity types have, which leads to a more complex Higher Order Mode (HOM) spectrum. In addition, spoke cavities offer a large velocity acceptance which means we must perform a detailed analysis of the particle velocity dependence for each mode's R/Q. We present here a study of the HOM properties of two-spoke cavities designed for high-velocity applications. Frequencies, R/Q and field profiles of HOMs have been calculated and are reported.

  13. Programming real-time executives in higher order language

    NASA Technical Reports Server (NTRS)

    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.

  14. Higher-order laser mode converters with dielectric metasurfaces.

    PubMed

    He, Yongli; Liu, Zhenxing; Liu, Yachao; Zhou, Junxiao; Ke, Yougang; Luo, Hailu; Wen, Shuangchun

    2015-12-01

    A simple and compact converter based on the dielectric metasurface is proposed for the transformation of Gaussian mode to Hermite-Gaussian and Laguerre-Gaussian modes. We establish the relationship between the phase of a desired mode and the local orientation of the optical axis based on the evolution of Pancharatnam-Berry phase on Poincaré sphere. By controlling the local orientation of the optical axis in the dielectric metasurface, we can achieve any desired higher-order laser mode. PMID:26625037

  15. Measurement of distributed strain and temperature based on higher order and higher mode Bragg conditions

    NASA Technical Reports Server (NTRS)

    Sirkis, James S. (Inventor); Sivanesan, Ponniah (Inventor); Venkat, Venki S. (Inventor)

    2001-01-01

    A Bragg grating sensor for measuring distributed strain and temperature at the same time comprises an optical fiber having a single mode operating wavelength region and below a cutoff wavelength of the fiber having a multimode operating wavelength region. A saturated, higher order Bragg grating having first and second order Bragg conditions is fabricated in the optical fiber. The first order of Bragg resonance wavelength of the Bragg grating is within the single mode operating wavelength region of the optical fiber and the second order of Bragg resonance wavelength is below the cutoff wavelength of the fiber within the multimode operating wavelength region. The reflectivities of the saturated Bragg grating at the first and second order Bragg conditions are less than two orders of magnitude of one another. In use, the first and second order Bragg conditions are simultaneously created in the sensor at the respective wavelengths and a signal from the sensor is demodulated with respect to each of the wavelengths corresponding to the first and second order Bragg conditions. Two Bragg conditions have different responsivities to strain and temperature, thus allowing two equations for axial strain and temperature to be found in terms of the measure shifts in the primary and second order Bragg wavelengths. This system of equations can be solved for strain and temperature.

  16. Inhibitory control gains from higher-order cognitive strategy training.

    PubMed

    Motes, Michael A; Gamino, Jacquelyn F; Chapman, Sandra B; Rao, Neena K; Maguire, Mandy J; Brier, Matthew R; Kraut, Michael A; Hart, John

    2014-02-01

    The present study examined the transfer of higher-order cognitive strategy training to inhibitory control. Middle school students enrolled in a comprehension- and reasoning-focused cognitive strategy training program and passive controls participated. The training program taught students a set of steps for inferring essential gist or themes from materials. Both before and after training or a comparable duration in the case of the passive controls, participants completed a semantically cued Go/No-Go task that was designed to assess the effects of depth of semantic processing on response inhibition and components of event-related potentials (ERP) related to response inhibition. Depth of semantic processing was manipulated by varying the level of semantic categorization required for response selection and inhibition. The SMART-trained group showed inhibitory control gains and changes in fronto-central P3 ERP amplitudes on inhibition trials; whereas, the control group did not. The results provide evidence of the transfer of higher-order cognitive strategy training to inhibitory control and modulation of ERPs associated with semantically cued inhibitory control. The findings are discussed in terms of implications for cognitive strategy training, models of cognitive abilities, and education. PMID:24286804

  17. Aero-optical jitter estimation using higher-order wavefronts

    NASA Astrophysics Data System (ADS)

    Whiteley, Matthew R.; Goorskey, David J.; Drye, Richard

    2013-07-01

    Wavefront measurements from wind tunnel or flight testing of an optical system are affected by jitter sources due to the measurement platform, system vibrations, or aero-mechanical buffeting. Depending on the nature of the testing, the wavefront jitter will be a composite of several effects, one of which is the aero-optical jitter; i.e., the wavefront tilt due to random air density fluctuations. To isolate the aero-optical jitter component from recent testing, we have developed an estimation technique that uses only higher-order wavefront measurements to determine the jitter. By analogy with work done previously with free-stream turbulence, we have developed a minimum mean-square error estimator using higher-order wavefront modes to compute the current-frame tilt components through a linear operation. The estimator is determined from computational fluid dynamics evaluation of aero-optical disturbances, but does not depend on the strength of such disturbances. Applying this technique to turret flight test data, we found aero-optical jitter to be 7.7±0.8 μrad and to scale with (ρ/ρSL)M2 (˜1 μrad in the actual test cases examined). The half-power point of the aero-optical jitter variance was found to be ˜2u∞/Dt and to roll off in temporal frequency with a power law between f and f.

  18. Laser-PlasmaWakefield Acceleration with Higher Order Laser Modes

    SciTech Connect

    Geddes, C.G.R.; Cormier-Michel, E.; Esarey, E.; Schroeder, C.B.; Mullowney, P.; Paul, K.; Cary, J.R.; Leemans, W.P.

    2010-06-01

    Laser-plasma collider designs point to staging of multiple accelerator stages at the 10 GeV level, which are to be developed on the upcoming BELLA laser, while Thomson Gamma source designs use GeV stages, both requiring efficiency and low emittance. Design and scaling of stages operating in the quasi-linear regime to address these needs are presented using simulations in the VORPAL framework. In addition to allowing symmetric acceleration of electrons and positrons, which is important for colliders, this regime has the property that the plasma wakefield is proportional to the transverse gradient of the laser intensity profile. We demonstrate use of higher order laser modes to tailor the laser pulse and hence the transverse focusing forces in the plasma. In particular, we show that by using higher order laser modes, we can reduce the focusing fields and hence increase the matched electron beam radius, which is important to increased charge and efficiency, while keeping the low bunch emittance required for applications.

  19. Higher Order Parametric Excitation Modes for Spaceborne Quadrupole Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    Gershman, D. J.; Block, B. P.; Rubin, M.; Benna, M.; Mahaffy, P. R.; Zurbuchen, T. H.

    2011-01-01

    This paper describes a technique to significantly improve upon the mass peak shape and mass resolution of spaceborne quadrupole mass spectrometers (QMSs) through higher order auxiliary excitation of the quadrupole field. Using a novel multiresonant tank circuit, additional frequency components can be used to drive modulating voltages on the quadrupole rods in a practical manner, suitable for both improved commercial applications and spaceflight instruments. Auxiliary excitation at frequencies near twice that of the fundamental quadrupole RF frequency provides the advantages of previously studied parametric excitation techniques, but with the added benefit of increased sensed excitation amplitude dynamic range and the ability to operate voltage scan lines through the center of upper stability islands. Using a field programmable gate array, the amplitudes and frequencies of all QMS signals are digitally generated and managed, providing a robust and stable voltage control system. These techniques are experimentally verified through an interface with a commercial Pfeiffer QMG422 quadrupole rod system.When operating through the center of a stability island formed from higher order auxiliary excitation, approximately 50% and 400% improvements in 1% mass resolution and peak stability were measured, respectively, when compared with traditional QMS operation. Although tested with a circular rod system, the presented techniques have the potential to improve the performance of both circular and hyperbolic rod geometry QMS sensors.

  20. Laser-Plasma Wakefield Acceleration with Higher Order Laser Modes

    SciTech Connect

    Geddes, C. G. R.; Schroeder, C. B.; Cormier-Michel, E.; Mullowney, P.; Paul, K.; Esarey, E.; Cary, J. R.; Leemans, W. P.

    2010-11-04

    Laser-plasma collider designs point to staging of multiple accelerator stages at the 10 GeV level, which are to be developed on the upcoming BELLA laser, while Thomson Gamma source designs use GeV stages, both requiring efficiency and low emittance. Design and scaling of stages operating in the quasi-linear regime to address these needs are presented using simulations in the VORPAL framework. In addition to allowing symmetric acceleration of electrons and positrons, which is important for colliders, this regime has the property that the plasma wakefield is proportional to the transverse gradient of the laser intensity profile. We demonstrate use of higher order laser modes to tailor the laser pulse and hence the transverse focusing forces in the plasma. In particular, we show that by using higher order laser modes, we can reduce the focusing fields and hence increase the matched electron beam radius, which is important to increased charge and efficiency, while keeping the low bunch emittance required for applications.

  1. Higher order parametric excitation modes for spaceborne quadrupole mass spectrometers

    SciTech Connect

    Gershman, D. J.; Block, B. P.; Rubin, M.; Zurbuchen, T. H.; Benna, M.; Mahaffy, P. R.

    2011-12-15

    This paper describes a technique to significantly improve upon the mass peak shape and mass resolution of spaceborne quadrupole mass spectrometers (QMSs) through higher order auxiliary excitation of the quadrupole field. Using a novel multiresonant tank circuit, additional frequency components can be used to drive modulating voltages on the quadrupole rods in a practical manner, suitable for both improved commercial applications and spaceflight instruments. Auxiliary excitation at frequencies near twice that of the fundamental quadrupole RF frequency provides the advantages of previously studied parametric excitation techniques, but with the added benefit of increased sensed excitation amplitude dynamic range and the ability to operate voltage scan lines through the center of upper stability islands. Using a field programmable gate array, the amplitudes and frequencies of all QMS signals are digitally generated and managed, providing a robust and stable voltage control system. These techniques are experimentally verified through an interface with a commercial Pfeiffer QMG422 quadrupole rod system. When operating through the center of a stability island formed from higher order auxiliary excitation, approximately 50% and 400% improvements in 1% mass resolution and peak stability were measured, respectively, when compared with traditional QMS operation. Although tested with a circular rod system, the presented techniques have the potential to improve the performance of both circular and hyperbolic rod geometry QMS sensors.

  2. Visualizing Higher Order Finite Elements: FY05 Yearly Report.

    SciTech Connect

    Thompson, David; Pebay, Philippe Pierre

    2005-11-01

    This report contains an algorithm for decomposing higher-order finite elementsinto regions appropriate for isosurfacing and proves the conditions under which thealgorithm will terminate. Finite elements are used to create piecewise polynomialapproximants to the solution of partial differential equations for which no analyticalsolution exists. These polynomials represent fields such as pressure, stress, and mo-mentim. In the past, these polynomials have been linear in each parametric coordinate.Each polynomial coefficient must be uniquely determined by a simulation, and thesecoefficients are called degrees of freedom. When there are not enough degrees of free-dom, simulations will typically fail to produce a valid approximation to the solution.Recent work has shown that increasing the number of degrees of freedom by increas-ing the order of the polynomial approximation (instead of increasing the number offinite elements, each of which has its own set of coefficients) can allow some typesof simulations to produce a valid approximation with many fewer degrees of freedomthan increasing the number of finite elements alone. However, once the simulation hasdetermined the values of all the coefficients in a higher-order approximant, tools donot exist for visual inspection of the solution.This report focuses on a technique for the visual inspection of higher-order finiteelement simulation results based on decomposing each finite element into simplicialregions where existing visualization algorithms such as isosurfacing will work. Therequirements of the isosurfacing algorithm are enumerated and related to the placeswhere the partial derivatives of the polynomial become zero. The original isosurfacingalgorithm is then applied to each of these regions in turn.3 AcknowledgementThe authors would like to thank David Day and Louis Romero for their insight into poly-nomial system solvers and the LDRD Senior Council for the opportunity to pursue thisresearch. The authors were

  3. Higher Order Mode Heating Analysis for the ILC Superconducting Linacs

    SciTech Connect

    Bane, K.L.F.; Nantista, C.; Adolphsen, C.; /SLAC

    2010-10-27

    The superconducting cavities and interconnects in the 11 km long linacs of the International Linear Collider (ILC) are designed to operate at 2K, where cooling costs are very expensive. It is thus important to minimize cryogenic heat loads. In addition to an unavoidable static load and the dynamic load of the fundamental 1.3 GHz accelerating rf, a further heat source is presented by the higher order mode (HOM) power deposited by the beam. Such modes will be damped by specially designed HOM couplers attached to the cavities (for trapped modes), and by ceramic dampers at 70K that are located between the eight or nine cavity cryomodules (for propagating modes). Brute force calculation of the higher frequency modes excited in a string of cryomodules is limited by computing capacity (see, e.g. [1]). M. Liepe has calculated {approx} 400 longitudinal TM modes in 3 superconducting cavities plus absorbers, up to 8 GHz [2]. Joestingmeier, et al., have used a ray tracing calculation to find the effect at higher frequencies, specifically in the range of tens of GHz and above [3]. In this report we present a scattering matrix approach, which we apply to an rf unit comprising 26 cavities and 3 absorbers. We perform calculations at sample frequencies (up to 20 GHz) to predict the effectiveness of the ceramic dampers in limiting HOM heat deposition at 2K.

  4. Higher-order phase transitions on financial markets

    NASA Astrophysics Data System (ADS)

    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

  5. A Recurrence Relation Approach to Higher Order Quantum Superintegrability

    NASA Astrophysics Data System (ADS)

    Kalnins, Ernie G.; Kress, Jonathan M.; Miller, Willard

    2011-03-01

    We develop our method to prove quantum superintegrability of an integrable 2D system, based on recurrence relations obeyed by the eigenfunctions of the system with respect to separable coordinates. We show that the method provides rigorous proofs of superintegrability and explicit constructions of higher order generators for the symmetry algebra. We apply the method to 5 families of systems, each depending on a parameter k, including most notably the caged anisotropic oscillator, the Tremblay, Turbiner and Winternitz system and a deformed Kepler-Coulomb system, and we give proofs of quantum superintegrability for all rational values of k, new for 4 of these systems. In addition, we show that the explicit information supplied by the special function recurrence relations allows us to prove, for the first time in 4 cases, that the symmetry algebra generated by our lowest order symmetries closes and to determine the associated structure equations of the algebras for each k. We have no proof that our generating symmetries are of lowest possible order, but we have no counterexamples, and we are confident we can can always find any missing generators from our raising and lowering operator recurrences. We also get for free, one variable models of the action of the symmetry algebra in terms of difference operators. We describe how the Stäckel transform acts and show that it preserves the structure equations.

  6. Higher-order spectra for identification of nonlinear modal coupling

    NASA Astrophysics Data System (ADS)

    Hickey, Daryl; Worden, Keith; Platten, Michael F.; Wright, Jan R.; Cooper, Jonathan E.

    2009-05-01

    Over the past four decades considerable work has been done in the area of power spectrum estimation. The information contained within the power spectrum relates to a signal's autocorrelation or 'second-order statistics'. The power spectrum provides a complete statistical description of a Gaussian process; however, a problem with this information is that it is phase blind. This problem is addressed if one turns to a system's frequency response function (FRF). The FRF graphs the magnitude and phase of the frequency response of a system; in order to do this it requires information regarding the frequency content of the input and output signals. Situations arise in science and engineering whereby signal analysts are required to look beyond second-order statistics and analyse a signal's higher-order statistics (HOS). HOS or spectra give information on a signal's deviation from Gaussianity and consequently are a good indicator function for the presence of nonlinearity within a system. One of the main problems in nonlinear system identification is that of high modal density. Many modelling schemes involve making some expansion of the nonlinear restoring force in terms of polynomial or other basis terms. If more than one degree-of-freedom is involved this becomes a multivariate problem and the number of candidate terms in the expansion grows explosively with the order of nonlinearity and the number of degrees-of-freedom. This paper attempts to use HOS to detect and qualify nonlinear behaviour for a number of symmetrical and asymmetrical systems over a range of degrees-of-freedom. In doing so the paper also attempts to show that HOS are a more sensitive tool than the FRF in detecting nonlinearity. Furthermore, the object of this paper is to try and identify which modes couple in a nonlinear manner in order to reduce the number of candidate coupling terms, for a model, as much as possible. The bispectrum method has previously been applied to simple low-DOF systems with high

  7. Novel Object Exploration as a Potential Assay for Higher Order Repetitive Behaviors in Mice.

    PubMed

    Steinbach, Jessica M; Garza, Elizabeth T; Ryan, Bryce C

    2016-01-01

    Restricted, repetitive behaviors (RRBs) are a core feature of autism spectrum disorder (ASD) and disrupt the lives of affected individuals. RRBs are commonly split into lower-order and higher-order components, with lower order RRBs consisting of motor stereotypies and higher order RRBs consisting of perseverative and sequencing behaviors. Higher order RRBs are challenging to model in mice. Current assays for RRBs in mice focus primarily on the lower order components, making basic biomedical research into potential treatments or interventions for higher-order RRBs difficult. Here we describe a new assay, novel object exploration. This assay uses a basic open-field arena with four novel objects placed around the perimeter. The test mouse is allowed to freely explore the arena and the order in which the mouse investigates the novel objects is recorded. From these data, patterned sequences of exploration can be identified, as can the most preferred object for each mouse. The representative data shared here and past results using the novel object exploration assay illustrate that inbred mouse strains do demonstrate different behavior in this assay and that strains with elevated lower order RRBs also show elevated patterned behavior. As such, the novel object exploration assay appears to possess good face validity for higher order RRBs in humans and may be a valuable assay for future studies investigating novel therapeutics for ASD. PMID:27583676

  8. Higher Order Aberration and Astigmatism in Children with Hyperopic Amblyopia

    PubMed Central

    Choi, Seung Kwon

    2016-01-01

    Purpose To investigate the changes in corneal higher-order aberration (HOA) during amblyopia treatment and the correlation between HOA and astigmatism in hyperopic amblyopia children. Methods In this retrospective study, a total of 72 eyes from 72 patients ranging in age from 38 to 161 months were included. Patients were divided into two groups based on the degree of astigmatism. Corneal HOA was measured using a KR-1W aberrometer at the initial visit and at 3-, 6-, and 12-month follow-ups. Correlation analysis was performed to assess the association between HOA and astigmatism. Results A total of 72 patients were enrolled in this study, 37 of which were classified as belonging to the higher astigmatism group, while 35 were assigned to the lower astigmatism group. There was a statistically significant difference in success rate between the higher and lower astigmatism groups. In both groups, all corneal HOAs were significantly reduced during amblyopia treatment. When comparing the two groups, a significant difference in coma HOA at the 12-month follow-up was detected (p = 0.043). In the Pearson correlation test, coma HOA at the 12-month follow-up demonstrated a statistically significant correlation with astigmatism and a stronger correlation with astigmatism in the higher astigmatism group than in the lower astigmatism group (coefficient values, 0.383 and 0.284 as well as p = 0.021 and p = 0.038, respectively). Conclusions HOA, particularly coma HOA, correlated with astigmatism and could exert effects in cases involving hyperopic amblyopia. PMID:26865804

  9. Polarization and visibility of higher-order rainbows.

    PubMed

    Können, Gunther P

    2015-02-01

    The degree of polarization of rainbows of order k with k≥3 is bounded in the interval [75%, 78%], where 75% is the limit for k→∞. A polarization filter can improve the signal-to-background ratio of the third and fourth rainbows by a factor of 2, which may lift their visibilities in natural circumstances above the threshold of human visual perception. Under optimal circumstances, the latter may be true for the recently photographed green fingerprint of the fifth rainbow, even without the aid of a polarization filter. The prospects for observing the sixth rainbow are unclear. There exists a possibility that the signal of the natural seventh rainbow (appearing at 64° from the Sun) may be separated from its background if photographed under perfect conditions through a polarization filter. PMID:25967836

  10. On negative higher-order Kerr effect and filamentation

    NASA Astrophysics Data System (ADS)

    Loriot, V.; Béjot, P.; Ettoumi, W.; Petit, Y.; Kasparian, J.; Henin, S.; Hertz, E.; Lavorel, B.; Faucher, O.; Wolf, J.-P.

    2011-07-01

    As a contribution to the ongoing controversy about the role of higher-order Kerr effect (HOKE) in laser filamentation, we first provide thorough details about the protocol that has been employed to infer the HOKE indices from the experiment. Next, we discuss potential sources of artifact in the experimental measurements of these terms and show that neither the value of the observed birefringence, nor its inversion, nor the intensity at which it is observed, appear to be flawed. Furthermore, we argue that, independently on our values, the principle of including HOKE is straightforward. Due to the different temporal and spectral dynamics, the respective efficiency of defocusing by the plasma and by the HOKE is expected to depend substantially on both incident wavelength and pulse duration. The discussion should therefore focus on defining the conditions where each filamentation regime dominates.

  11. Neutron scattering studies on chromatin higher-order structure

    SciTech Connect

    Graziano, V.; Gerchman, S.E.; Schneider, D.K.; Ramakrishnan, V.

    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.

  12. Steganographic system based on higher-order statistics

    NASA Astrophysics Data System (ADS)

    Tzschoppe, Roman; Baeuml, Robert; Huber, Johannes; Kaup, Andre

    2003-06-01

    Universal blind steganalysis attempts to detect steganographic data without knowledge about the applied steganographic system. Farid proposed such a detection algorithm based on higher-order statistics for separating original images from stego images. His method shows an astonishing performance on current steganographic schemes. Starting from the statistical approach in Farid's algorithm, we investigate the well known steganographic tool Jsteg as well as a newer approach proposed by Eggers et al., which relies on histogram-preserving data mapping. Both schemes show weaknesses leading to a certain detectability. Further analysis shows which statistic characteristics make both schemes vulnerable. Based on these results, the histogram preserving approach is enhanced such that it achieves perfect security with respect to Farid's algorithm.

  13. Higher-order resonances in a Stark decelerator

    SciTech Connect

    Meerakker, Sebastiaan Y.T. van de; Bethlem, Hendrick L.; Vanhaecke, Nicolas; Meijer, Gerard

    2005-05-15

    The motion of polar molecules can be controlled by time-varying inhomogeneous electric fields. In a Stark decelerator, this is exploited to select a fraction of a molecular beam that is accelerated, transported, or decelerated. Phase stability ensures that the selected bunch of molecules is kept together throughout the deceleration process. In this paper an extended description of phase stability in a Stark decelerator is given, including higher-order effects. This analysis predicts a wide variety of resonances that originate from the spatial and temporal periodicity of the electric fields. These resonances are experimentally observed using a beam of OH ({sup 2}{pi}{sub 3/2},v=0,J=3/2) radicals passing through a Stark decelerator.

  14. Revealing Higher Order Protein Structure Using Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Chait, Brian T.; Cadene, Martine; Olinares, Paul Dominic; Rout, Michael P.; Shi, Yi

    2016-06-01

    The development of rapid, sensitive, and accurate mass spectrometric methods for measuring peptides, proteins, and even intact protein assemblies has made mass spectrometry (MS) an extraordinarily enabling tool for structural biology. Here, we provide a personal perspective of the increasingly useful role that mass spectrometric techniques are exerting during the elucidation of higher order protein structures. Areas covered in this brief perspective include MS as an enabling tool for the high resolution structural biologist, for compositional analysis of endogenous protein complexes, for stoichiometry determination, as well as for integrated approaches for the structural elucidation of protein complexes. We conclude with a vision for the future role of MS-based techniques in the development of a multi-scale molecular microscope.

  15. Pulse transmission transmitter including a higher order time derivate filter

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-09-23

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A pulse transmission transmitter includes: a clock; a pseudorandom polynomial generator coupled to the clock, the pseudorandom polynomial generator having a polynomial load input; an exclusive-OR gate coupled to the pseudorandom polynomial generator, the exclusive-OR gate having a serial data input; a programmable delay circuit coupled to both the clock and the exclusive-OR gate; a pulse generator coupled to the programmable delay circuit; and a higher order time derivative filter coupled to the pulse generator. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  16. Inflationary scenarios in Starobinsky model with higher order corrections

    SciTech Connect

    Artymowski, Michał; Lalak, Zygmunt; Lewicki, Marek

    2015-06-17

    We consider the Starobinsky inflation with a set of higher order corrections parametrised by two real coefficients λ{sub 1} ,λ{sub 2}. In the Einstein frame we have found a potential with the Starobinsky plateau, steep slope and possibly with an additional minimum, local maximum or a saddle point. We have identified three types of inflationary behaviour that may be generated in this model: i) inflation on the plateau, ii) at the local maximum (topological inflation), iii) at the saddle point. We have found limits on parameters λ{sub i} and initial conditions at the Planck scale which enable successful inflation and disable eternal inflation at the plateau. We have checked that the local minimum away from the GR vacuum is stable and that the field cannot leave it neither via quantum tunnelling nor via thermal corrections.

  17. Evaluative conditioning depends on higher order encoding processes.

    PubMed

    Fiedler, Klaus; Unkelbach, Christian

    2011-06-01

    Evaluative conditioning (EC) is commonly conceived as stimulus-driven associative learning. Here, we show that internally generated encoding activities mediate EC effects: Neutral conditioned stimuli (CS) faces were paired with positive and negative unconditioned stimuli (US) faces. Depending on the encoding task (Is CS a friend vs. enemy of US?), Experiment 1 yielded either normal EC effects (CS adopting US valence) or a reversal. This pattern was conditional on the degree to which encoding judgements affirmed friend or enemy encoding schemes. Experiments 2a and 2b replicated these findings with more clearly valenced US faces and controlling for demand effects. Experiment 3 demonstrated unconditional encoding effects when participants generated friend or enemy relations between CS and US faces. Explicitly stated friend or enemy relations in Experiment 4 left EC effects unaffected. Together, these findings testify to the importance of higher order cognitive processes in conditioning, much in line with recent evidence on the crucial role of conditioning awareness. PMID:21547766

  18. Dependable software through higher-order strategic programming.

    SciTech Connect

    Winter, Victor Lono; Fraij, Fares; Roach, Steve

    2004-03-01

    Program transformation is a restricted form of software construction that can be amenable to formal verification. When successful, the nature of the evidence provided by such a verification is considered strong and can constitute a major component of an argument that a high-consequence or safety-critical system meets its dependability requirements. This article explores the application of novel higher-order strategic programming techniques to the development of a portion of a class loader for a restricted implementation of the Java Virtual Machine (JVM). The implementation is called the SSP and is intended for use in high-consequence safety-critical embedded systems. Verification of the strategic program using ACL2 is also discussed.

  19. Revealing Higher Order Protein Structure Using Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Chait, Brian T.; Cadene, Martine; Olinares, Paul Dominic; Rout, Michael P.; Shi, Yi

    2016-04-01

    The development of rapid, sensitive, and accurate mass spectrometric methods for measuring peptides, proteins, and even intact protein assemblies has made mass spectrometry (MS) an extraordinarily enabling tool for structural biology. Here, we provide a personal perspective of the increasingly useful role that mass spectrometric techniques are exerting during the elucidation of higher order protein structures. Areas covered in this brief perspective include MS as an enabling tool for the high resolution structural biologist, for compositional analysis of endogenous protein complexes, for stoichiometry determination, as well as for integrated approaches for the structural elucidation of protein complexes. We conclude with a vision for the future role of MS-based techniques in the development of a multi-scale molecular microscope.

  20. Detailed Modeling of Higher Order Hierarchical Kepler Star Systems

    NASA Astrophysics Data System (ADS)

    Gore, Joanna; Orosz, Jerome A.

    2016-06-01

    Most stars have stellar companions (i.e. they exist in double, triple, or higher order configurations). Binary star systems are those which contain two stars. These systems are valued scientifically because they allow for the measurement of fundamental stellar properties such as masses and radii. These properties in turn allow for detailed studies of stellar evolution. The Kepler space telescope has discovered roughly 2900 eclipsing binary stars in its field of view. Various studies have shown that roughly 20% of the Kepler eclipsing binaries contain companions are are most likely triple star systems. We present a preliminary survey of the orbital properties of the tertiary bodies in a sample of thirty triple systems. In addition, a small number of the triple systems show eclipse events due to the third star. We present the results of detailed modeling of two of these systems, and discuss how in some cases these triple systems allow for extremely precise measurements of the fundamental stellar parameters.

  1. Revealing Higher Order Protein Structure Using Mass Spectrometry.

    PubMed

    Chait, Brian T; Cadene, Martine; Olinares, Paul Dominic; Rout, Michael P; Shi, Yi

    2016-06-01

    The development of rapid, sensitive, and accurate mass spectrometric methods for measuring peptides, proteins, and even intact protein assemblies has made mass spectrometry (MS) an extraordinarily enabling tool for structural biology. Here, we provide a personal perspective of the increasingly useful role that mass spectrometric techniques are exerting during the elucidation of higher order protein structures. Areas covered in this brief perspective include MS as an enabling tool for the high resolution structural biologist, for compositional analysis of endogenous protein complexes, for stoichiometry determination, as well as for integrated approaches for the structural elucidation of protein complexes. We conclude with a vision for the future role of MS-based techniques in the development of a multi-scale molecular microscope. Graphical Abstract ᅟ. PMID:27080007

  2. Higher Order Mode Excitations in Gyro-amplifiers

    NASA Astrophysics Data System (ADS)

    Nguyen, Khanh

    2000-10-01

    A key element in the design of gyro-amplifier RF structures is the minimization of unwanted modes. For example, a nonlinear output taper is often employed in the transition from the near cutoff radius of the interacting circuit to a much larger output waveguide, which also serves as the collector. The taper designs are usually done without considering the effect of a bunched beam. However, recent simulations [1] with the self-consistent MAGY code [2] reveal that higher order mode interactions with the bunched electron beam can substantially compromise the mode purity of the RF output. The interaction in the taper region is that of a travelling-wave type and is strongly dependent on the beam bunching characteristics resulting from previous interaction with the operating mode in the interacting circuit. Subsequent to this prediction, an experiment was performed to measure the RF output mode content from a Ka-band gyro-klystron at the Naval Research Laboratory. The agreement between salient theoretical and measured RF output characteristics confirms the existence higher order mode excitation in output tapers as predicted by theory. Another example of the need to employ self-consistent theoretical model in the design of gyro-amplifier RF structures is the phenomenon of beam-induced RF excitation in drift sections, which are cutoff to the operating mode and are used to separate cavities in gyroklystron amplifiers. This non-resonant RF excitation is at the drive frequency and the RF field structure is that of the operating mode. The RF amplitude is found to scale linearly with the bunched beam current. The presence of RF in the drift section has important thermal implications in the design and use of lossy dielectrics in drift-sections, especially for high-average power devices. [1] K. Nguyen, et al., IEEE Trans. Plasma Science, in press 2000. [2] M. Botton, et al., IEEE Trans. Plasma Science, V.26, p.882, June 1998.

  3. First and Higher Order Effects on Zero Order Radiative Transfer Model

    NASA Astrophysics Data System (ADS)

    Neelam, M.; Mohanty, B.

    2014-12-01

    Microwave radiative transfer model are valuable tool in understanding the complex land surface interactions. Past literature has largely focused on local sensitivity analysis for factor priotization and ignoring the interactions between the variables and uncertainties around them. Since land surface interactions are largely nonlinear, there always exist uncertainties, heterogeneities and interactions thus it is important to quantify them to draw accurate conclusions. In this effort, we used global sensitivity analysis to address the issues of variable uncertainty, higher order interactions, factor priotization and factor fixing for zero-order radiative transfer (ZRT) model. With the to-be-launched Soil Moisture Active Passive (SMAP) mission of NASA, it is very important to have a complete understanding of ZRT for soil moisture retrieval to direct future research and cal/val field campaigns. This is a first attempt to use GSA technique to quantify first order and higher order effects on brightness temperature from ZRT model. Our analyses reflect conditions observed during the growing agricultural season for corn and soybeans in two different regions in - Iowa, U.S.A and Winnipeg, Canada. We found that for corn fields in Iowa, there exist significant second order interactions between soil moisture, surface roughness parameters (RMS height and correlation length) and vegetation parameters (vegetation water content, structure and scattering albedo), whereas in Winnipeg, second order interactions are mainly due to soil moisture and vegetation parameters. But for soybean fields in both Iowa and Winnipeg, we found significant interactions only to exist between soil moisture and surface roughness parameters.

  4. SPHS: smoothed particle hydrodynamics with a higher order dissipation switch

    NASA Astrophysics Data System (ADS)

    Read, J. I.; Hayfield, T.

    2012-06-01

    We present a novel implementation of smoothed particle hydrodynamics that uses the spatial derivative of the velocity divergence as a higher order dissipation switch. Our switch - which is second order accurate - detects flow convergence before it occurs. If particle trajectories are going to cross, we switch on the usual SPH artificial viscosity, as well as conservative dissipation in all advected fluid quantities (e.g. the entropy). The viscosity and dissipation terms (that are numerical errors) are designed to ensure that all fluid quantities remain single valued as particles approach one another, to respect conservation laws, and to vanish on a given physical scale as the resolution is increased. SPHS alleviates a number of known problems with 'classic' SPH, successfully resolving mixing, and recovering numerical convergence with increasing resolution. An additional key advantage is that - treating the particle mass similarly to the entropy - we are able to use multimass particles, giving significantly improved control over the refinement strategy. We present a wide range of code tests including the Sod shock tube, Sedov-Taylor blast wave, Kelvin-Helmholtz Instability, the 'blob test' and some convergence tests. Our method performs well on all tests, giving good agreement with analytic expectations.

  5. Phantom Friedmann cosmologies and higher-order characteristics of expansion

    SciTech Connect

    Dabrowski, Mariusz P. . E-mail: mpdabfz@sus.univ.szczecin.pl; Stachowiak, Tomasz . E-mail: toms@oa.uj.edu.pl

    2006-04-15

    We discuss a more general class of phantom (p < -{rho}) cosmologies with various forms of both phantom (w < -1), and standard (w > -1) matter. We show that many types of evolution which include both Big-Bang and Big-Rip singularities are admitted and give explicit examples. Among some interesting models, there exist non-singular oscillating (or 'bounce') cosmologies, which appear due to a competition between positive and negative pressure of variety of matter content. From the point of view of the current observations the most interesting cosmologies are the ones which start with a Big-Bang and terminate at a Big-Rip. A related consequence of having a possibility of two types of singularities is that there exists an unstable static universe approached by the two asymptotic models-one of them reaches Big-Bang, and another reaches Big-Rip. We also give explicit relations between density parameters {omega} and the dynamical characteristics for these generalized phantom models, including higher-order observational characteristics such as jerk and 'kerk.' Finally, we discuss the observational quantities such as luminosity distance, angular diameter, and source counts, both in series expansion and explicitly, for phantom models. Our series expansion formulas for the luminosity distance and the apparent magnitude go as far as to the fourth-order in redshift z term, which includes explicitly not only the jerk, but also the 'kerk' (or 'snap') which may serve as an indicator of the curvature of the universe.

  6. Higher-order spike triggered analysis of neural oscillators.

    PubMed

    Ota, Keisuke; Omori, Toshiaki; Miyakawa, Hiroyoshi; Okada, Masato; Aonishi, Toru

    2012-01-01

    For the purpose of elucidating the neural coding process based on the neural excitability mechanism, researchers have recently investigated the relationship between neural dynamics and the spike triggered stimulus ensemble (STE). Ermentrout et al. analytically derived the relational equation between the phase response curve (PRC) and the spike triggered average (STA). The STA is the first cumulant of the STE. However, in order to understand the neural function as the encoder more explicitly, it is necessary to elucidate the relationship between the PRC and higher-order cumulants of the STE. In this paper, we give a general formulation to relate the PRC and the nth moment of the STE. By using this formulation, we derive a relational equation between the PRC and the spike triggered covariance (STC), which is the covariance of the STE. We show the effectiveness of the relational equation through numerical simulations and use the equation to identify the feature space of the rat hippocampal CA1 pyramidal neurons from their PRCs. Our result suggests that the hippocampal CA1 pyramidal neurons oscillating in the theta frequency range are commonly sensitive to inputs composed of theta and gamma frequency components. PMID:23226249

  7. Separating higher-order nonlinearities in transient absorption microscopy

    NASA Astrophysics Data System (ADS)

    Wilson, Jesse W.; Anderson, Miguel; Park, Jong Kang; Fischer, Martin C.; Warren, Warren S.

    2015-08-01

    The transient absorption response of melanin is a promising optically-accessible biomarker for distinguishing malignant melanoma from benign pigmented lesions, as demonstrated by earlier experiments on thin sections from biopsied tissue. The technique has also been demonstrated in vivo, but the higher optical intensity required for detecting these signals from backscattered light introduces higher-order nonlinearities in the transient response of melanin. These components that are higher than linear with respect to the pump or the probe introduce intensity-dependent changes to the overall response that complicate data analysis. However, our data also suggest these nonlinearities might be advantageous to in vivo imaging, in that different types of melanins have different nonlinear responses. Therefore, methods to separate linear from nonlinear components in transient absorption measurements might provide additional information to aid in the diagnosis of melanoma. We will discuss numerical methods for analyzing the various nonlinear contributions to pump-probe signals, with the ultimate objective of real time analysis using digital signal processing techniques. To that end, we have replaced the lock-in amplifier in our pump-probe microscope with a high-speed data acquisition board, and reprogrammed the coprocessor field-programmable gate array (FPGA) to perform lock-in detection. The FPGA lock-in offers better performance than the commercial instrument, in terms of both signal to noise ratio and speed. In addition, the flexibility of the digital signal processing approach enables demodulation of more complicated waveforms, such as spread-spectrum sequences, which has the potential to accelerate microscopy methods that rely on slow relaxation phenomena, such as photo-thermal and phosphorescence lifetime imaging.

  8. The effect of higher order harmonics on second order nonlinear phenomena

    NASA Astrophysics Data System (ADS)

    Shahverdi, Amin; Borji, Amir

    2015-05-01

    A new method which is a combination of the harmonic balance and finite difference techniques (HBFD) is proposed for complete time-harmonic solution of the nonlinear wave equation. All interactions between different harmonics up to an arbitrary order can be incorporated. The effect of higher order harmonics on two important nonlinear optical phenomena, namely, the second harmonic generation (SHG) and frequency mixing is investigated by this method and the results are compared with well-known analytical solutions. The method is quite general and can be used to study wave propagation in all nonlinear media.

  9. Student's Perceived Level and Teachers' Teaching Strategies of Higher Order Thinking Skills: A Study on Higher Educational Institutions in Thailand

    ERIC Educational Resources Information Center

    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…

  10. Higher-order Fourier analysis over finite fields and applications

    NASA Astrophysics Data System (ADS)

    Hatami, Pooya

    Higher-order Fourier analysis is a powerful tool in the study of problems in additive and extremal combinatorics, for instance the study of arithmetic progressions in primes, where the traditional Fourier analysis comes short. In recent years, higher-order Fourier analysis has found multiple applications in computer science in fields such as property testing and coding theory. In this thesis, we develop new tools within this theory with several new applications such as a characterization theorem in algebraic property testing. One of our main contributions is a strong near-equidistribution result for regular collections of polynomials. The densities of small linear structures in subsets of Abelian groups can be expressed as certain analytic averages involving linear forms. Higher-order Fourier analysis examines such averages by approximating the indicator function of a subset by a function of bounded number of polynomials. Then, to approximate the average, it suffices to know the joint distribution of the polynomials applied to the linear forms. We prove a near-equidistribution theorem that describes these distributions for the group F(n/p) when p is a fixed prime. This fundamental fact was previously known only under various extra assumptions about the linear forms or the field size. We use this near-equidistribution theorem to settle a conjecture of Gowers and Wolf on the true complexity of systems of linear forms. Our next application is towards a characterization of testable algebraic properties. We prove that every locally characterized affine-invariant property of functions f : F(n/p) → R with n∈ N, is testable. In fact, we prove that any such property P is proximity-obliviously testable. More generally, we show that any affine-invariant property that is closed under subspace restrictions and has "bounded complexity" is testable. We also prove that any property that can be described as the property of decomposing into a known structure of low

  11. Higher-Order Finite Elements for Computing Thermal Radiation

    NASA Technical Reports Server (NTRS)

    Gould, Dana C.

    2004-01-01

    Two variants of the finite-element method have been developed for use in computational simulations of radiative transfers of heat among diffuse gray surfaces. Both variants involve the use of higher-order finite elements, across which temperatures and radiative quantities are assumed to vary according to certain approximations. In this and other applications, higher-order finite elements are used to increase (relative to classical finite elements, which are assumed to be isothermal) the accuracies of final numerical results without having to refine computational meshes excessively and thereby incur excessive computation times. One of the variants is termed the radiation sub-element (RSE) method, which, itself, is subject to a number of variations. This is the simplest and most straightforward approach to representation of spatially variable surface radiation. Any computer code that, heretofore, could model surface-to-surface radiation can incorporate the RSE method without major modifications. In the basic form of the RSE method, each finite element selected for use in computing radiative heat transfer is considered to be a parent element and is divided into sub-elements for the purpose of solving the surface-to-surface radiation-exchange problem. The sub-elements are then treated as classical finite elements; that is, they are assumed to be isothermal, and their view factors and absorbed heat fluxes are calculated accordingly. The heat fluxes absorbed by the sub-elements are then transferred back to the parent element to obtain a radiative heat flux that varies spatially across the parent element. Variants of the RSE method involve the use of polynomials to interpolate and/or extrapolate to approximate spatial variations of physical quantities. The other variant of the finite-element method is termed the integration method (IM). Unlike in the RSE methods, the parent finite elements are not subdivided into smaller elements, and neither isothermality nor other

  12. A viscoelastic higher-order beam finite element

    NASA Technical Reports Server (NTRS)

    Johnson, Arthur R.; Tressler, Alexander

    1996-01-01

    A viscoelastic internal variable constitutive theory is applied to a higher-order elastic beam theory and finite element formulation. The behavior of the viscous material in the beam is approximately modeled as a Maxwell solid. The finite element formulation requires additional sets of nodal variables for each relaxation time constant needed by the Maxwell solid. Recent developments in modeling viscoelastic material behavior with strain variables that are conjugate to the elastic strain measures are combined with advances in modeling through-the-thickness stresses and strains in thick beams. The result is a viscous thick-beam finite element that possesses superior characteristics for transient analysis since its nodal viscous forces are not linearly dependent an the nodal velocities, which is the case when damping matrices are used. Instead, the nodal viscous forces are directly dependent on the material's relaxation spectrum and the history of the nodal variables through a differential form of the constitutive law for a Maxwell solid. The thick beam quasistatic analysis is explored herein as a first step towards developing more complex viscoelastic models for thick plates and shells, and for dynamic analyses. The internal variable constitutive theory is derived directly from the Boltzmann superposition theorem. The mechanical strains and the conjugate internal strains are shown to be related through a system of first-order, ordinary differential equations. The total time-dependent stress is the superposition of its elastic and viscous components. Equations of motion for the solid are derived from the virtual work principle using the total time-dependent stress. Numerical examples for the problems of relaxation, creep, and cyclic creep are carried out for a beam made from an orthotropic Maxwell solid.

  13. Higher-order graph wavelets and sparsity on circulant graphs

    NASA Astrophysics Data System (ADS)

    Kotzagiannidis, Madeleine S.; Dragotti, Pier Luigi

    2015-08-01

    The notion of a graph wavelet gives rise to more advanced processing of data on graphs due to its ability to operate in a localized manner, across newly arising data-dependency structures, with respect to the graph signal and underlying graph structure, thereby taking into consideration the inherent geometry of the data. In this work, we tackle the problem of creating graph wavelet filterbanks on circulant graphs for a sparse representation of certain classes of graph signals. The underlying graph can hereby be data-driven as well as fixed, for applications including image processing and social network theory, whereby clusters can be modelled as circulant graphs, respectively. We present a set of novel graph wavelet filter-bank constructions, which annihilate higher-order polynomial graph signals (up to a border effect) defined on the vertices of undirected, circulant graphs, and are localised in the vertex domain. We give preliminary results on their performance for non-linear graph signal approximation and denoising. Furthermore, we provide extensions to our previously developed segmentation-inspired graph wavelet framework for non-linear image approximation, by incorporating notions of smoothness and vanishing moments, which further improve performance compared to traditional methods.

  14. Invariants of velocities and higher-order Grassmann bundles

    NASA Astrophysics Data System (ADS)

    Grigore, Dan Radu; Krupka, Demeter

    1998-02-01

    An ( r, n)-velocity is an r-jet with source at 0 ɛ Rn, and target in a manifold Y. An ( r, n)-velocity is said to be regular if it has a representative which is an immersion at 0 ɛ Rn. The manifold TnrY of ( r, n)-velocities as well as its open, Lnr-invariant, dense submanifold Imm TnrY of regular ( r, n)-velocities, are endowed with a natural action of the differential group Lnr of invertible r-jets with source and target 0 ɛ Rn. In this paper, we describe all continuous, Lnr-invariant, real-valued functions on TnrY and Imm TnrY. We find local bases of Lnr-invariants Imm TnrY in an explicit, recurrent form. To this purpose, higher-order Grassmann bundles are considered as the corresponding quotients P nrY = Imm{T nrY }/{L nr}, and their basic properties are studied. We show that nontrivial Lnr-invariants on Imm TnrY cannot be continuously extended onto TnrY.

  15. Transcriptional Derepression Uncovers Cryptic Higher-Order Genetic Interactions

    PubMed Central

    Taylor, Matthew B.; Ehrenreich, Ian M.

    2015-01-01

    Disruption of certain genes can reveal cryptic genetic variants that do not typically show phenotypic effects. Because this phenomenon, which is referred to as ‘phenotypic capacitance’, is a potential source of trait variation and disease risk, it is important to understand how it arises at the genetic and molecular levels. Here, we use a cryptic colony morphology trait that segregates in a yeast cross to explore the mechanisms underlying phenotypic capacitance. We find that the colony trait is expressed when a mutation in IRA2, a negative regulator of the Ras pathway, co-occurs with specific combinations of cryptic variants in six genes. Four of these genes encode transcription factors that act downstream of the Ras pathway, indicating that the phenotype involves genetically complex changes in the transcriptional regulation of Ras targets. We provide evidence that the IRA2 mutation reveals the phenotypic effects of the cryptic variants by disrupting the transcriptional silencing of one or more genes that contribute to the trait. Supporting this role for the IRA2 mutation, deletion of SFL1, a repressor that acts downstream of the Ras pathway, also reveals the phenotype, largely due to the same cryptic variants that were detected in the IRA2 mutant cross. Our results illustrate how higher-order genetic interactions among mutations and cryptic variants can result in phenotypic capacitance in specific genetic backgrounds, and suggests these interactions might reflect genetically complex changes in gene expression that are usually suppressed by negative regulation. PMID:26484664

  16. Higher-order web link analysis using multilinear algebra.

    SciTech Connect

    Kenny, Joseph P.; Bader, Brett William; Kolda, Tamara Gibson

    2005-07-01

    Linear algebra is a powerful and proven tool in web search. Techniques, such as the PageRank algorithm of Brin and Page and the HITS algorithm of Kleinberg, score web pages based on the principal eigenvector (or singular vector) of a particular non-negative matrix that captures the hyperlink structure of the web graph. We propose and test a new methodology that uses multilinear algebra to elicit more information from a higher-order representation of the hyperlink graph. We start by labeling the edges in our graph with the anchor text of the hyperlinks so that the associated linear algebra representation is a sparse, three-way tensor. The first two dimensions of the tensor represent the web pages while the third dimension adds the anchor text. We then use the rank-1 factors of a multilinear PARAFAC tensor decomposition, which are akin to singular vectors of the SVD, to automatically identify topics in the collection along with the associated authoritative web pages.

  17. Higher-Order Synaptic Interactions Coordinate Dynamics in Recurrent Networks

    PubMed Central

    Chambers, Brendan; MacLean, Jason N.

    2016-01-01

    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. PMID:27542093

  18. Spectral imaging to visualize higher-order genomic organization.

    PubMed

    Sawyer, Iain A; Shevtsov, Sergei P; Dundr, Miroslav

    2016-05-01

    A concern in the field of genomics is the proper interpretation of large, high-throughput sequencing datasets. The use of DNA FISH followed by high-content microscopy is a valuable tool for validation and contextualization of frequently occurring gene pairing events at the single-cell level identified by deep sequencing. However, these techniques possess certain limitations. Firstly, they do not permit the study of colocalization of many gene loci simultaneously. Secondly, the direct assessment of the relative position of many clustered gene loci within their respective chromosome territories is impossible. Thus, methods are required to advance the study of higher-order nuclear and cellular organization. Here, we describe a multiplexed DNA FISH technique combined with indirect immunofluorescence to study the relative position of 6 distinct genomic or cellular structures. This can be achieved in a single hybridization step using spectral imaging during image acquisition and linear unmixing. Here, we detail the use of this method to quantify gene pairing between highly expressed spliceosomal genes and compare these data to randomly positioned in silico simulated gene clusters. This is a potentially universally applicable approach for the validation of 3C-based technologies, deep imaging of spatial organization within the nucleus and global cellular organization. PMID:27167405

  19. Generation of Higher Order Modes in a Rectangular Duct

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Cabell, Randolph H.; Brown, Donald E.

    2004-01-01

    Advanced noise control methodologies to reduce sound emission from aircraft engines take advantage of the modal structure of the noise in the duct. This noise is caused by the interaction of rotor wakes with downstream obstructions such as exit guide vanes. Mode synthesis has been accomplished in circular ducts and current active noise control work has made use of this capability to cancel fan noise. The goal of the current effort is to examine the fundamental process of higher order mode propagation through an acoustically treated, curved duct. The duct cross-section is rectangular to permit greater flexibility in representation of a range of duct curvatures. The work presented is the development of a feedforward control system to generate a user-specified modal pattern in the duct. The multiple-error, filtered-x LMS algorithm is used to determine the magnitude and phase of signal input to the loudspeakers to produce a desired modal pattern at a set of error microphones. Implementation issues, including loudspeaker placement and error microphone placement, are discussed. Preliminary results from a 9-3/8 inch by 21 inch duct, using 12 loudspeakers and 24 microphones, are presented. These results demonstrate the ability of the control system to generate a user-specified mode while suppressing undesired modes.

  20. Higher-Order Synaptic Interactions Coordinate Dynamics in Recurrent Networks.

    PubMed

    Chambers, Brendan; MacLean, Jason N

    2016-08-01

    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. PMID:27542093

  1. Pressure and higher-order spectra for homogeneous isotropic turbulence

    NASA Technical Reports Server (NTRS)

    Pullin, D. I.; Rogallo, R. S.

    1994-01-01

    The spectra of the pressure, and other higher-order quantities including the dissipation, the enstrophy, and the square of the longitudinal velocity derivative are computed using data obtained from direct numerical simulation of homogeneous isotropic turbulence at Taylor-Reynolds numbers R(sub lambda) in the range 38 - 170. For the pressure spectra we find reasonable collapse in the dissipation range (of the velocity spectrum) when scaled in Kolmogorov variables and some evidence, which is not conclusive, for the existence of a k(exp -7/3) inertial range where k = absolute value of K, is the modulus of the wavenumber. The power spectra of the dissipation, the enstrophy, and the square of the longitudinal velocity derivative separate in the dissipation range, but appear to converge together in the short inertial range of the simulations. A least-squares curve-fit in the dissipation range for one value of R(sub lambda) = 96 gives a form for the spectrum of the dissipation as k(exp 0)exp(-Ck eta), for k(eta) greater than 0.2, where eta is the Kolmogorov length and C is approximately equal to 2.5.

  2. Higher order finite element analysis of thick composite laminates

    NASA Technical Reports Server (NTRS)

    Goering, J.; Kim, H. J.

    1992-01-01

    A higher order, sub-parametric, laminated, 3D solid finite element was used for the analysis of very thick laminated composite plates. The geometry of this element is defined by four nodes in the X-Y plane which define a prism of material through the thickness of the laminate. There are twenty-four degrees of freedom at each node; translations at the upper and lower surfaces of the laminate in each of the three coordinate directions, and the derivatives of these translations with respect to each coordinate. This choice of degrees of freedom leads to displacement and strain compatibility at the corners. Stacking sequence effects are accounted for by explicitly integrating the strain energy density through the thickness of the element. The laminated solid element was combined with a gap-contact element to analyze thick laminated composite lugs loaded through flexible pins. The resulting model accounts for pin bending effects that produce non-uniform bearing stresses through the thickness of the lug. A thick composite lug experimental test program was performed, and provided data that was used to validate the analytical model. Two lug geometries and three stacking sequences were tested.

  3. Image Segmentation Using Higher-Order Correlation Clustering.

    PubMed

    Kim, Sungwoong; Yoo, Chang D; Nowozin, Sebastian; Kohli, Pushmeet

    2014-09-01

    In this paper, a hypergraph-based image segmentation framework is formulated in a supervised manner for many high-level computer vision tasks. To consider short- and long-range dependency among various regions of an image and also to incorporate wider selection of features, a higher-order correlation clustering (HO-CC) is incorporated in the framework. Correlation clustering (CC), which is a graph-partitioning algorithm, was recently shown to be effective in a number of applications such as natural language processing, document clustering, and image segmentation. It derives its partitioning result from a pairwise graph by optimizing a global objective function such that it simultaneously maximizes both intra-cluster similarity and inter-cluster dissimilarity. In the HO-CC, the pairwise graph which is used in the CC is generalized to a hypergraph which can alleviate local boundary ambiguities that can occur in the CC. Fast inference is possible by linear programming relaxation, and effective parameter learning by structured support vector machine is also possible by incorporating a decomposable structured loss function. Experimental results on various data sets show that the proposed HO-CC outperforms other state-of-the-art image segmentation algorithms. The HO-CC framework is therefore an efficient and flexible image segmentation framework. PMID:26352230

  4. A general higher-order remap algorithm for ALE calculations

    SciTech Connect

    Chiravalle, Vincent P

    2011-01-05

    A numerical technique for solving the equations of fluid dynamics with arbitrary mesh motion is presented. The three phases of the Arbitrary Lagrangian Eulerian (ALE) methodology are outlined: the Lagrangian phase, grid relaxation phase and remap phase. The Lagrangian phase follows a well known approach from the HEMP code; in addition the strain rate andflow divergence are calculated in a consistent manner according to Margolin. A donor cell method from the SALE code forms the basis of the remap step, but unlike SALE a higher order correction based on monotone gradients is also added to the remap. Four test problems were explored to evaluate the fidelity of these numerical techniques, as implemented in a simple test code, written in the C programming language, called Cercion. Novel cell-centered data structures are used in Cercion to reduce the complexity of the programming and maximize the efficiency of memory usage. The locations of the shock and contact discontinuity in the Riemann shock tube problem are well captured. Cercion demonstrates a high degree of symmetry when calculating the Sedov blast wave solution, with a peak density at the shock front that is similar to the value determined by the RAGE code. For a flyer plate test problem both Cercion and FLAG give virtually the same velocity temporal profile at the target-vacuum interface. When calculating a cylindrical implosion of a steel shell, Cercion and FLAG agree well and the Cercion results are insensitive to the use of ALE.

  5. Higher order structure of proteins solubilized in AOT reverse micelles.

    PubMed

    Naoe, Kazumitsu; Noda, Kazuki; Kawagoe, Mikio; Imai, Masanao

    2004-11-15

    The higher order structure of proteins solubilized in an bis(2-ethylhexyl) sulfosuccinate sodium (AOT) reverse micellar system was investigated. From circular dichroic (CD) measurement, CD spectra of cytochrome c, which is solubilized at the interface of reverse micelles, markedly changed on going from buffer solution to the reverse micellar solution, and the ellipticity values in the far- and near-UV regions decreased with decreasing the water content (W0: molar ratio of water to AOT), indicating that the secondary and tertiary structures of cytochrome c changed with the water content. The ellipticity of ribonuclease A, which is solubilized in the center of micellar water pool, in the near-UV region was dependent on W0 and became minimum when W0 of ca. 8 while the ellipticity in the far-UV region was almost constant, indicating that the tertiary structure of ribonuclease A was affected by the water content, but the secondary structure was conserved. The degree of curvature of the micellar interface appears to influence the protein structure because the reverse micelle size is linearly proportional to the W0 value. As evidence of this, when the micelle size was comparable to the protein's dimensions, the structures were more affected by the water content. Judging from the dependence of the factor influencing the protein structure on the protein species, the location of solubilized protein in reverse micelles is significantly related to whether the protein structure in the system is affected by the micellar interface. In the cases of cytochrome c and lysozyme, the ellipticity against W0 was dependent on the AOT concentration. In contrast, ribonuclease A gave very similar ellipticity values whatever the AOT concentration. In the n-hexane micellar system, cytochrome c exhibited lower ellipticity values and ribonuclease A in the lower W0 range (W0higher ellipticity values. These results indicated that the interaction between the protein and the micellar

  6. Higher-order renormalization of graphene many-body theory

    NASA Astrophysics Data System (ADS)

    González, J.

    2012-08-01

    We study the many-body theory of graphene Dirac quasiparticles interacting via the long-range Coulomb potential, taking as a starting point the ladder approximation to different vertex functions. We test in this way the low-energy behavior of the electron system beyond the simple logarithmic dependence of electronic correlators on the high-energy cutoff, which is characteristic of the large- N approximation. We show that the graphene many-body theory is perfectly renormalizable in the ladder approximation, as all higher powers in the cutoff dependence can be absorbed into the redefinition of a finite number of parameters (namely, the Fermi velocity and the weight of the fields) that remain free of infrared divergences even at the charge neutrality point. We illustrate this fact in the case of the vertex for the current density, where a complete cancellation between the cutoff dependences of vertex and electron self-energy corrections becomes crucial for the preservation of the gauge invariance of the theory. The other potentially divergent vertex corresponds to the staggered (sublattice odd) charge density, which is made cutoff independent by a redefinition in the scale of the density operator. This allows to compute a well-defined, scale invariant anomalous dimension to all orders in the ladder series, which becomes singular at a value of the interaction strength marking the onset of chiral symmetry breaking (and gap opening) in the Dirac field theory. The critical coupling we obtain in this way matches with great accuracy the value found with a quite different method, based on the resolution of the gap equation, thus reassuring the predictability of our renormalization approach.

  7. Divergence of Mammalian Higher Order Chromatin Structure Is Associated with Developmental Loci

    PubMed Central

    Chambers, Emily V.; Bickmore, Wendy A.; Semple, Colin A.

    2013-01-01

    Several recent studies have examined different aspects of mammalian higher order chromatin structure – replication timing, lamina association and Hi-C inter-locus interactions — and have suggested that most of these features of genome organisation are conserved over evolution. However, the extent of evolutionary divergence in higher order structure has not been rigorously measured across the mammalian genome, and until now little has been known about the characteristics of any divergent loci present. Here, we generate a dataset combining multiple measurements of chromatin structure and organisation over many embryonic cell types for both human and mouse that, for the first time, allows a comprehensive assessment of the extent of structural divergence between mammalian genomes. Comparison of orthologous regions confirms that all measurable facets of higher order structure are conserved between human and mouse, across the vast majority of the detectably orthologous genome. This broad similarity is observed in spite of many loci possessing cell type specific structures. However, we also identify hundreds of regions (from 100 Kb to 2.7 Mb in size) showing consistent evidence of divergence between these species, constituting at least 10% of the orthologous mammalian genome and encompassing many hundreds of human and mouse genes. These regions show unusual shifts in human GC content, are unevenly distributed across both genomes, and are enriched in human subtelomeric regions. Divergent regions are also relatively enriched for genes showing divergent expression patterns between human and mouse ES cells, implying these regions cause divergent regulation. Particular divergent loci are strikingly enriched in genes implicated in vertebrate development, suggesting important roles for structural divergence in the evolution of mammalian developmental programmes. These data suggest that, though relatively rare in the mammalian genome, divergence in higher order chromatin

  8. Dynamics and phenomenology of higher order gravity cosmological models

    NASA Astrophysics Data System (ADS)

    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

  9. Construction of higher order accurate vortex and particle methods

    NASA Technical Reports Server (NTRS)

    Nicolaides, R. A.

    1986-01-01

    The standard point vortex method has recently been shown to be of high order of accuracy for problems on the whole plane, when using a uniform initial subdivision for assigning the vorticity to the points. If obstacles are present in the flow, this high order deteriorates to first or second order. New vortex methods are introduced which are of arbitrary accuracy (under regularity assumptions) regardless of the presence of bodies and the uniformity of the initial subdivision.

  10. Correcting vortex splitting in higher order vortex beams.

    PubMed

    Neo, Richard; Tan, Shiaw Juen; Zambrana-Puyalto, Xavier; Leon-Saval, Sergio; Bland-Hawthorn, Joss; Molina-Terriza, Gabriel

    2014-04-21

    We demonstrate a general method for the first order compensation of singularity splitting in a vortex beam at a single plane. By superimposing multiple forked holograms on the SLM used to generate the vortex beam, we are able to compensate vortex splitting and generate beams with desired phase singularities of order ℓ = 0, 1, 2, and 3 in one plane. We then extend this method by application of a radial phase, in order to simultaneously compensate the observed vortex splitting at two planes (near and far field) for an ℓ = 2 beam. PMID:24787874

  11. Higher-order diagrammatic vibrational coupled-cluster theory

    NASA Astrophysics Data System (ADS)

    Faucheaux, Jacob A.; Hirata, So

    2015-10-01

    Diagrammatically size-consistent and basis-set-free vibrational coupled-cluster (XVCC) theory for both zero-point energies and transition frequencies of a molecule, the latter through the equation-of-motion (EOM) formalism, is defined for an nth-order Taylor-series potential energy surface (PES). Quantum-field-theoretical tools (the rules of normal-ordered second quantization and Feynman-Goldstone diagrams) for deriving their working equations are established. The equations of XVCC and EOM-XVCC including up to the mth-order excitation operators are derived and implemented with the aid of computer algebra in the range of 1 ≤ m ≤ 8. Algorithm optimizations known as strength reduction, intermediate reuse, and factorization are carried out before code generation, reducing the cost scaling of the mth-order XVCC and EOM-XVCC in an nth-order Taylor-series PES (m ≥ n) to the optimal value of O(Nm+⌊n/2⌋), where N is the number of modes. The calculated zero-point energies and frequencies of fundamentals, overtones, and combinations as well as Fermi-resonant modes display rapid and nearly monotonic convergence with m towards the exact values for the PES. The theory with the same excitation rank as the truncation order of the Taylor-series PES (m = n) seems to strike the best cost-accuracy balance, achieving the accuracy of a few tenths of cm-1 for transitions involving (m - 3) modes and of a few cm-1 for those involving (m - 2) modes. The relationships between XVCC and the vibrational coupled-cluster theories of Prasad and coworkers and of Christiansen and coworkers as well as the size-extensive vibrational self-consistent-field and many-body perturbation theories are also elucidated.

  12. Higher-order diagrammatic vibrational coupled-cluster theory.

    PubMed

    Faucheaux, Jacob A; Hirata, So

    2015-10-01

    Diagrammatically size-consistent and basis-set-free vibrational coupled-cluster (XVCC) theory for both zero-point energies and transition frequencies of a molecule, the latter through the equation-of-motion (EOM) formalism, is defined for an nth-order Taylor-series potential energy surface (PES). Quantum-field-theoretical tools (the rules of normal-ordered second quantization and Feynman-Goldstone diagrams) for deriving their working equations are established. The equations of XVCC and EOM-XVCC including up to the mth-order excitation operators are derived and implemented with the aid of computer algebra in the range of 1 ≤ m ≤ 8. Algorithm optimizations known as strength reduction, intermediate reuse, and factorization are carried out before code generation, reducing the cost scaling of the mth-order XVCC and EOM-XVCC in an nth-order Taylor-series PES (m ≥ n) to the optimal value of O(N(m+⌊n/2⌋)), where N is the number of modes. The calculated zero-point energies and frequencies of fundamentals, overtones, and combinations as well as Fermi-resonant modes display rapid and nearly monotonic convergence with m towards the exact values for the PES. The theory with the same excitation rank as the truncation order of the Taylor-series PES (m = n) seems to strike the best cost-accuracy balance, achieving the accuracy of a few tenths of cm(-1) for transitions involving (m - 3) modes and of a few cm(-1) for those involving (m - 2) modes. The relationships between XVCC and the vibrational coupled-cluster theories of Prasad and coworkers and of Christiansen and coworkers as well as the size-extensive vibrational self-consistent-field and many-body perturbation theories are also elucidated. PMID:26450290

  13. The Structure of Higher Education: Order in the Academy

    ERIC Educational Resources Information Center

    Smith, Clair A.

    2009-01-01

    Higher education in the U.S. is provided by an interesting mix of public, private non-profit, and for-profit institutions. The for-profit educational firm serves the residual claimant owners and has the greatest incentive for efficient operation. The public and private non-profit schools have less efficient incentives, but benefit from charitable…

  14. A Short Note on Rules and Higher Order Rules.

    ERIC Educational Resources Information Center

    Scandura, Joseph M.

    This brief paper argues that structural analysis--an extended form of cognitive task analysis--demonstrates that both domain dependent and domain independent knowledge can be derived from specific content domains. It is noted that the major difference between the two is that lower order rules (specific knowledge) are derived directly from specific…

  15. Higher-Order Semi-Implicit Projection Methods

    SciTech Connect

    Minion, M L

    2001-09-06

    A semi-implicit form of the method of spectral deferred corrections is applied to the solution of the incompressible Navier-Stokes equations. A methodology for constructing semi-implicit projection methods with arbitrarily high order of temporal accuracy in both the velocity and pressure is presented. Three variations of projection methods are discussed which differ in the manner in which the auxiliary velocity and the pressure are calculated. The presentation will make clear that project methods in general need not be viewed as fractional step methods as is often the practice. Two simple numerical examples re used to demonstrate fourth-order accuracy in time for an implementation of each variation of projection method.

  16. Higher order chromatin structure: bridging physics and biology

    PubMed Central

    Fudenberg, Geoffrey; Mirny, Leonid A.

    2012-01-01

    Recent advances in microscopy and genomic techniques have provided new insight into spatial chromatin organization inside of the nucleus. In particular, chromosome conformation capture data has highlighted the relevance of polymer physics for high-order chromatin organization. In this context, we review basic polymer states, discuss how an appropriate polymer model can be determined from experimental data, and examine the success and limitations of various polymer models of high-order interphase chromatin organization. By taking into account topological constraints acting on the chromatin fiber, recently-developed polymer models of interphase chromatin can reproduce the observed scaling of distances between genomic loci, chromosomal territories, and probabilities of contacts between loci measured by chromosome conformation capture methods. Polymer models provide a framework for the interpretation of experimental data as ensembles of conformations rather than collections of loops, and will be crucial for untangling functional implications of chromosomal organization. PMID:22360992

  17. Higher-order numerical solutions using cubic splines

    NASA Technical Reports Server (NTRS)

    Rubin, S. G.; Khosla, P. K.

    1976-01-01

    A cubic spline collocation procedure was developed for the numerical solution of partial differential equations. This spline procedure is reformulated so that the accuracy of the second-derivative approximation is improved and parallels that previously obtained for lower derivative terms. The final result is a numerical procedure having overall third-order accuracy of a nonuniform mesh. Solutions using both spline procedures, as well as three-point finite difference methods, are presented for several model problems.

  18. Machine learning using a higher order correlation network

    SciTech Connect

    Lee, Y.C.; Doolen, G.; Chen, H.H.; Sun, G.Z.; Maxwell, T.; Lee, H.Y.

    1986-01-01

    A high-order correlation tensor formalism for neural networks is described. The model can simulate auto associative, heteroassociative, as well as multiassociative memory. For the autoassociative model, simulation results show a drastic increase in the memory capacity and speed over that of the standard Hopfield-like correlation matrix methods. The possibility of using multiassociative memory for a learning universal inference network is also discussed. 9 refs., 5 figs.

  19. Wavelet steerability and the higher-order Riesz transform.

    PubMed

    Unser, Michael; Van De Ville, Dimitri

    2010-03-01

    Our main goal in this paper is to set the foundations of a general continuous-domain framework for designing steerable, reversible signal transformations (a.k.a. frames) in multiple dimensions ( d >or= 2). To that end, we introduce a self-reversible, Nth-order extension of the Riesz transform. We prove that this generalized transform has the following remarkable properties: shift-invariance, scale-invariance, inner-product preservation, and steerability. The pleasing consequence is that the transform maps any primary wavelet frame (or basis) of [Formula: see text] into another "steerable" wavelet frame, while preserving the frame bounds. The concept provides a functional counterpart to Simoncelli's steerable pyramid whose construction was primarily based on filterbank design. The proposed mechanism allows for the specification of wavelets with any order of steerability in any number of dimensions; it also yields a perfect reconstruction filterbank algorithm. We illustrate the method with the design of a novel family of multidimensional Riesz-Laplace wavelets that essentially behave like the N th-order partial derivatives of an isotropic Gaussian kernel. PMID:20031498

  20. Higher-order symplectic Born-Oppenheimer molecular dynamics

    SciTech Connect

    Niklasson, Anders; Bock, Nicolas; Challacombe, Matt; Odell, Anders; Delin, Anna; Johansson, Borje

    2009-01-01

    The extended Lagrangian formulation of time-reversible Born-Oppenheimer molecular dynamics (TR-BOMD) enables the use of geometric integrators in the propagation of both the nuclear and the electronic degrees of freedom on the Born-Oppenheimer potential energy surface. Different symplectic integrators up to the 6th order have been adapted and optimized to TR-BOMD in the framework of ab initio self-consistent-field theory. It is shown how the accuracy can be significantly improved compared to a conventional Verlet integration at the same level of computational cost, in particular for the case of very high accuracy requirements.

  1. Higher-order gravitational lensing reconstruction using Feynman diagrams

    SciTech Connect

    Jenkins, Elizabeth E.; Manohar, Aneesh V.; Yadav, Amit P.S.; Waalewijn, Wouter J. E-mail: amanohar@ucsd.edu E-mail: ayadav@physics.ucsd.edu

    2014-09-01

    We develop a method for calculating the correlation structure of the Cosmic Microwave Background (CMB) using Feynman diagrams, when the CMB has been modified by gravitational lensing, Faraday rotation, patchy reionization, or other distorting effects. This method is used to calculate the bias of the Hu-Okamoto quadratic estimator in reconstructing the lensing power spectrum up to  O (φ{sup 4}) in the lensing potential φ. We consider both the diagonal noise TT TT, EB EB, etc. and, for the first time, the off-diagonal noise TT TE, TB EB, etc. The previously noted large  O (φ{sup 4}) term in the second order noise is identified to come from a particular class of diagrams. It can be significantly reduced by a reorganization of the φ expansion. These improved estimators have almost no bias for the off-diagonal case involving only one B component of the CMB, such as EE EB.

  2. Higher-order Boltzmann machines and entropy bounds

    NASA Astrophysics Data System (ADS)

    Apolloni, Bruno; Battistini, Egidio; de Falco, Diego

    1999-07-01

    We examine some aspects of the interface area between mathematical statistics and statistical physics relevant to the study of Boltzmann machines. The Boltzmann machine learning algorithm is based on a variational principle (Gibbs' lemma for relative entropy). This fact suggests the possibility of a scheme of successive approximations: here we consider successive approximations parametrized by the order of many-body interactions among individual units. We prove bounds on the gain in relative entropy in the crucial step of adding, and estimating by Hebb's rule, a new parameter. We address the problem of providing, on the basis of local observations, upper and lower bounds on the entropy. While upper bounds are easily obtained by subadditivity, lower bounds involve localization of Hirschman bounds on a dual quantum system.

  3. A probabilistic model of visual working memory: Incorporating higher order regularities into working memory capacity estimates.

    PubMed

    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 structure and treats items independently from one another. We present a probabilistic model of change detection that attempts to bridge this gap by formalizing the role of perceptual organization and allowing for richer, more structured memory representations. Using either standard visual working memory displays or displays in which the items are purposefully arranged in patterns, we find that models that take into account perceptual grouping between items and the encoding of higher order summary information are necessary to account for human change detection performance. Considering the higher order structure of items in visual working memory will be critical for models to make useful predictions about observers' memory capacity and change detection abilities in simple displays as well as in more natural scenes. PMID:23230888

  4. Higher order vortex gyrotropic modes in circular ferromagnetic nanodots.

    PubMed

    Ding, Junjia; Kakazei, Gleb N; Liu, Xinming; Guslienko, Konstantin Y; Adeyeye, Adekunle O

    2014-01-01

    Magnetic vortex that consists of an in-plane curling magnetization configuration and a needle-like core region with out-of-plane magnetization is known to be the ground state of geometrically confined submicron soft magnetic elements. Here magnetodynamics of relatively thick (50-100 nm) circular Ni80Fe20 dots were probed by broadband ferromagnetic resonance in the absence of external magnetic field. Spin excitation modes related to the thickness dependent vortex core gyrotropic dynamics were detected experimentally in the gigahertz frequency range. Both analytical theory and micromagnetic simulations revealed that these exchange dominated modes are flexure oscillations of the vortex core string with n = 0,1,2 nodes along the dot thickness. The intensity of the mode with n = 1 depends significantly on both dot thickness and diameter and in some cases is higher than the one of the uniform mode with n = 0. This opens promising perspectives in the area of spin transfer torque oscillators. PMID:24762659

  5. Superintegrability and higher order integrals for quantum systems

    NASA Astrophysics Data System (ADS)

    Kalnins, E. G.; Kress, J. M.; Miller, W., Jr.

    2010-07-01

    We refine a method for finding a canonical form of symmetry operators of arbitrary order for the Schrödinger eigenvalue equation HΨ ≡ (Δ2 + V)Ψ = EΨ on any 2D Riemannian manifold, real or complex, that admits a separation of variables in some orthogonal coordinate system. The flat space equations with potentials V = α(x + iy)k - 1/(x - iy)k + 1 in Cartesian coordinates, and V = αr2 + β/r2cos 2kθ + γ/r2sin 2kθ (the Tremblay, Turbiner and Winternitz system) in polar coordinates, have each been shown to be classically superintegrable for all rational numbers k. We apply the canonical operator method to give a constructive proof that each of these systems is also quantum superintegrable for all rational k. We develop the classical analog of the quantum canonical form for a symmetry. It is clear that our methods will generalize to other Hamiltonian systems.

  6. Higher order Peregrine breathers solutions to the NLS equation

    NASA Astrophysics Data System (ADS)

    Gaillard, Pierre

    2015-09-01

    The solutions to the one dimensional focusing nonlinear Schrodinger equation (NLS) can be written as a product of an exponential depending on t by a quotient of two polynomials of degree N(N + 1) in x and t. These solutions depend on 2N - 2 parameters : when all these parameters are equal to 0, we obtain the famous Peregrine breathers which we call PN breathers. Between all quasi-rational solutions of rank N fixed by the condition that its absolute value tends to 1 at infinity and its highest maximum is located at point (x = 0,t = 0), the PN breather is distinguished by the fact that PN (0, 0) = 2N + 1. We construct Peregrine breathers of the rank N explicitly for N ≤ 11. We give figures of these PN breathers in the (x; t) plane; plots of the solutions PN (0; t), PN (x;0), never given for 6 < N < 11 are constructed in this work. It is the first time that the Peregrine breather of order 11 is explicitly constructed.

  7. Binary higher order neural networks for realizing Boolean functions.

    PubMed

    Zhang, Chao; Yang, Jie; Wu, Wei

    2011-05-01

    In order to more efficiently realize Boolean functions by using neural networks, we propose a binary product-unit neural network (BPUNN) and a binary π-ς neural network (BPSNN). The network weights can be determined by one-step training. It is shown that the addition " σ," the multiplication " π," and two kinds of special weighting operations in BPUNN and BPSNN can implement the logical operators " ∨," " ∧," and " ¬" on Boolean algebra 〈Z(2),∨,∧,¬,0,1〉 (Z(2)={0,1}), respectively. The proposed two neural networks enjoy the following advantages over the existing networks: 1) for a complete truth table of N variables with both truth and false assignments, the corresponding Boolean function can be realized by accordingly choosing a BPUNN or a BPSNN such that at most 2(N-1) hidden nodes are needed, while O(2(N)), precisely 2(N) or at most 2(N), hidden nodes are needed by existing networks; 2) a new network BPUPS based on a collaboration of BPUNN and BPSNN can be defined to deal with incomplete truth tables, while the existing networks can only deal with complete truth tables; and 3) the values of the weights are all simply -1 or 1, while the weights of all the existing networks are real numbers. Supporting numerical experiments are provided as well. Finally, we present the risk bounds of BPUNN, BPSNN, and BPUPS, and then analyze their probably approximately correct learnability. PMID:21427020

  8. The Meaning of Higher-Order Factors in Reflective-Measurement Models

    ERIC Educational Resources Information Center

    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…

  9. MJO structure associated with the higher-order CEOF modes

    NASA Astrophysics Data System (ADS)

    Liu, Ping

    2014-10-01

    the total 432 CEOF modes retain all variance of the baseline MJO, while those higher than 10 contain less information and more noise and can be discarded. Furthermore, this study indicated that the longitudinal STD of the reconstructed anomalies detects the MJO phases and magnitudes in the western Pacific with more physical meaning and in better agreement with the Hovmöller diagrams than the RMM-like amplitude. The results provide an integral figure of the MJO structure from the CEOF analysis and a more robust RMM framework for monitoring the MJO's evolution in real time and for validating its numerical forecast and simulations.

  10. Higher-order multipole amplitudes in charmonium radiative transitions

    NASA Astrophysics Data System (ADS)

    Artuso, M.; Blusk, S.; Khalil, S.; Mountain, R.; Randrianarivony, K.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Zhang, L. M.; Bonvicini, G.; Cinabro, D.; Lincoln, A.; Smith, M. J.; Zhou, P.; Zhu, J.; Naik, P.; Rademacker, J.; Asner, D. M.; Edwards, K. W.; Reed, J.; Robichaud, A. N.; Tatishvili, G.; White, E. J.; Briere, R. A.; Vogel, H.; Onyisi, P. U. E.; Rosner, J. L.; Alexander, J. P.; Cassel, D. G.; Ehrlich, R.; Fields, L.; Galik, R. S.; Gibbons, L.; Gray, S. W.; Hartill, D. L.; Heltsley, B. K.; Hunt, J. M.; Kreinick, D. L.; Kuznetsov, V. E.; Ledoux, J.; Mahlke-Krüger, H.; Patterson, J. R.; Peterson, D.; Riley, D.; Ryd, A.; Sadoff, A. J.; Shi, X.; Stroiney, S.; Sun, W. M.; Yelton, J.; Rubin, P.; Lowrey, N.; Mehrabyan, S.; Selen, M.; Wiss, J.; Kornicer, M.; Mitchell, R. E.; Shepherd, M. R.; Tarbert, C. M.; Besson, D.; Pedlar, T. K.; Xavier, J.; Cronin-Hennessy, D.; Gao, K. Y.; Hietala, J.; Poling, R.; Zweber, P.; Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tan, B. J. Y.; Tomaradze, A.; Brisbane, S.; Libby, J.; Martin, L.; Powell, A.; Spradlin, P.; Thomas, C.; Wilkinson, G.; Mendez, H.; Ge, J. Y.; Miller, D. H.; Shipsey, I. P. J.; Xin, B.; Adams, G. S.; Hu, D.; Moziak, B.; Napolitano, J.; Ecklund, K. M.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H.; Yang, F.

    2009-12-01

    Using 24×106 ψ'≡ψ(2S) decays in CLEO-c, we have searched for higher multipole admixtures in electric-dipole-dominated radiative transitions in charmonia. We find good agreement between our data and theoretical predictions for magnetic quadrupole (M2) amplitudes in the transitions ψ'→γχc1,c2 and χc1,c2→γJ/ψ, in striking contrast to some previous measurements. Let b2J and a2J denote the normalized M2 amplitudes in the respective aforementioned decays, where the superscript J refers to the angular momentum of the χcJ. By performing unbinned maximum likelihood fits to full five-parameter angular distributions, we found the following values of M2 admixtures for Jχ=1: a2J=1=(-6.26±0.63±0.24)×10-2 and b2J=1=(2.76±0.73±0.23)×10-2, which agree well with theoretical expectations for a vanishing anomalous magnetic moment of the charm quark. For Jχ=2, if we fix the electric octupole (E3) amplitudes to zero as theory predicts for transitions between charmonium S states and P states, we find a2J=2=(-9.3±1.6±0.3)×10-2 and b2J=2=(1.0±1.3±0.3)×10-2. If we allow for E3 amplitudes we find, with a four-parameter fit, a2J=2=(-7.9±1.9±0.3)×10-2, b2J=2=(0.2±1.4±0.4)×10-2, a3J=2=(1.7±1.4±0.3)×10-2, and b3J=2=(-0.8±1.2±0.2)×10-2. We determine the ratios a2J=1/a2J=2=0.67-0.13+0.19 and a2J=1/b2J=1=-2.27-0.99+0.57, where the theoretical predictions are independent of the charmed quark magnetic moment and are a2J=1/a2J=2=0.676±0.071 and a2J=1/b2J=1=-2.27±0.16.

  11. Landscape of Higher Education: Human Capital

    ERIC Educational Resources Information Center

    Edwards, Kelcey; Perfetto, Greg; Hossler, Don; Kelly, Patrick J.

    2012-01-01

    There are many changes occurring in higher education, and often it is difficult to see trends nationally. In this presentation, experts working with national data present trends in higher education from a forward-looking perspective. Senior researchers from the College Board provide trends using College Board SAT and AP data, as well as new…

  12. Higher order accurate partial implicitization: An unconditionally stable fourth-order-accurate explicit numerical technique

    NASA Technical Reports Server (NTRS)

    Graves, R. A., Jr.

    1975-01-01

    The previously obtained second-order-accurate partial implicitization numerical technique used in the solution of fluid dynamic problems was modified with little complication to achieve fourth-order accuracy. The Von Neumann stability analysis demonstrated the unconditional linear stability of the technique. The order of the truncation error was deduced from the Taylor series expansions of the linearized difference equations and was verified by numerical solutions to Burger's equation. For comparison, results were also obtained for Burger's equation using a second-order-accurate partial-implicitization scheme, as well as the fourth-order scheme of Kreiss.

  13. Cross-phase modulational instability in an elliptical birefringent fiber with higher order nonlinearity and dispersion

    NASA Astrophysics Data System (ADS)

    Ganapathy, R.; Kuriakose, V. C.

    2002-04-01

    We obtain conditions for the occurrence of cross-phase modulational instability in the normal dispersion regime for the coupled higher order nonlinear Schrödinger equation with higher order dispersion and nonlinear terms.

  14. Landscape of Higher Education: Human Capital

    ERIC Educational Resources Information Center

    Edwards, Kelcey; Sawtell, Ellen; Perfetto, Greg; Shapiro, Douglas T.; Kelly, Patrick J.

    2013-01-01

    In this session presented at the Middle States Regional Forum (February 2013), experts working with national data presented trends in higher education from a forward-looking perspective. Senior researchers from the College Board provided trends using SAT, AP, and Net Price Calculator data. The research director of the National Student…

  15. An expansion formula with higher-order derivatives for fractional operators of variable order.

    PubMed

    Almeida, Ricardo; Torres, Delfim F M

    2013-01-01

    We obtain approximation formulas for fractional integrals and derivatives of Riemann-Liouville and Marchaud types with a variable fractional order. The approximations involve integer-order derivatives only. An estimation for the error is given. The efficiency of the approximation method is illustrated with examples. As applications, we show how the obtained results are useful to solve differential equations, and problems of the calculus of variations that depend on fractional derivatives of Marchaud type. PMID:24319382

  16. The use of higher-order statistics in rapid object categorization in natural scenes.

    PubMed

    Banno, Hayaki; Saiki, Jun

    2015-01-01

    We can rapidly and efficiently recognize many types of objects embedded in complex scenes. What information supports this object recognition is a fundamental question for understanding our visual processing. We investigated the eccentricity-dependent role of shape and statistical information for ultrarapid object categorization, using the higher-order statistics proposed by Portilla and Simoncelli (2000). Synthesized textures computed by their algorithms have the same higher-order statistics as the originals, while the global shapes were destroyed. We used the synthesized textures to manipulate the availability of shape information separately from the statistics. We hypothesized that shape makes a greater contribution to central vision than to peripheral vision and that statistics show the opposite pattern. Results did not show contributions clearly biased by eccentricity. Statistical information demonstrated a robust contribution not only in peripheral but also in central vision. For shape, the results supported the contribution in both central and peripheral vision. Further experiments revealed some interesting properties of the statistics. They are available for a limited time, attributable to the presence or absence of animals without shape, and predict how easily humans detect animals in original images. Our data suggest that when facing the time constraint of categorical processing, higher-order statistics underlie our significant performance for rapid categorization, irrespective of eccentricity. PMID:25761343

  17. SMARCA4 regulates gene expression and higher-order chromatin structure in proliferating mammary epithelial cells.

    PubMed

    Barutcu, A Rasim; Lajoie, Bryan R; Fritz, Andrew J; McCord, Rachel P; Nickerson, Jeffrey A; van Wijnen, Andre J; Lian, Jane B; Stein, Janet L; Dekker, Job; Stein, Gary S; Imbalzano, Anthony N

    2016-09-01

    The packaging of DNA into chromatin plays an important role in transcriptional regulation and nuclear processes. Brahma-related gene-1 SMARCA4 (also known as BRG1), the essential ATPase subunit of the mammalian SWI/SNF chromatin remodeling complex, uses the energy from ATP hydrolysis to disrupt nucleosomes at target regions. Although the transcriptional role of SMARCA4 at gene promoters is well-studied, less is known about its role in higher-order genome organization. SMARCA4 knockdown in human mammary epithelial MCF-10A cells resulted in 176 up-regulated genes, including many related to lipid and calcium metabolism, and 1292 down-regulated genes, some of which encode extracellular matrix (ECM) components that can exert mechanical forces and affect nuclear structure. ChIP-seq analysis of SMARCA4 localization and SMARCA4-bound super-enhancers demonstrated extensive binding at intergenic regions. Furthermore, Hi-C analysis showed extensive SMARCA4-mediated alterations in higher-order genome organization at multiple resolutions. First, SMARCA4 knockdown resulted in clustering of intra- and inter-subtelomeric regions, demonstrating a novel role for SMARCA4 in telomere organization. SMARCA4 binding was enriched at topologically associating domain (TAD) boundaries, and SMARCA4 knockdown resulted in weakening of TAD boundary strength. Taken together, these findings provide a dynamic view of SMARCA4-dependent changes in higher-order chromatin organization and gene expression, identifying SMARCA4 as a novel component of chromatin organization. PMID:27435934

  18. Assessing School Work Culture: A Higher-Order Analysis and Strategy.

    ERIC Educational Resources Information Center

    Johnson, William L.; Johnson, Annabel M.; Zimmerman, Kurt J.

    This paper reviews a work culture productivity model and reports the development of a work culture instrument based on the culture productivity model. Higher order principal components analysis was used to assess work culture, and a third-order factor analysis shows how the first-order factors group into higher-order factors. The school work…

  19. Evidence for the distortion product frequency place as a source of distortion product otoacoustic emission (DPOAE) fine structure in humans. I. Fine structure and higher-order DPOAE as a function of the frequency ratio f2/f1.

    PubMed

    Mauermann, M; Uppenkamp, S; van Hengel, P W; Kollmeier, B

    1999-12-01

    Critical experiments were performed in order to validate the two-source hypothesis of distortion product otoacoustic emissions (DPOAE) generation. Measurements of the spectral fine structure of DPOAE in response to stimulation with two sinusoids have been performed with normal-hearing subjects. The dependence of fine-structure patterns on the frequency ratio f2/f1 was investigated by changing f1 or f2 only (fixed f2 or fixed f1 paradigm, respectively), and by changing both primaries at a fixed ratio and looking at different order DPOAE. When f2/f1 is varied in the fixed ratio paradigm, the patterns of 2 f1-f2 fine structure vary considerably more if plotted as a function of f2 than as a function of fDP. Different order distortion products located at the same characteristic place on the basilar membrane (BM) show similar patterns for both, the fixed-f2 and fDP paradigms. Fluctuations in DPOAE level up to 20 dB can be observed. In contrast, the results from a fixed-fDP paradigm do not show any fine structure but only an overall dependence of DP level on the frequency ratio, with a maximum for 2f1-f2 at f2/f1 close to 1.2. Similar stimulus configurations used in the experiments have also been used for computer simulations of DPOAE in a nonlinear and active model of the cochlea. Experimental results and model simulations give strong evidence for a two-source model of DPOAE generation: The first source is the initial nonlinear interaction of the primaries close to the f2 place. The second source is caused by coherent reflection from a re-emission site at the characteristic place of the distortion product frequency. The spectral fine structure of DPOAE observed in the ear canal reflects the interaction of both these sources. PMID:10615687

  20. [Second-order retrospective revaluation in human contingency learning].

    PubMed

    Numata, Keitaro; Shimazaki, Tsuneo

    2009-04-01

    We demonstrated second-order retrospective revaluation with three cues (T1, T2, and C) and an outcome, in human contingency learning. Experimental task, PC-controlled video game in which participants were required to observe about the relations between firing missiles and the tank destruction, consisted of three training phases and two rating phases. Groups C+ and C- consisted of same first two training phases, CT+ (cues C and T with an outcome) and T1T2+ followed by C+, or C- training for Groups C+, C-, respectively. In rating phases, it is clearly demonstrated that the judgment of predictive value for the outcome of the T2 were higher by C+ training (second-order unovershadowing) and lowered by C- training (second-order backward blocking). The results for Groups RC+ and RC-, in which the orders of the first two training phase for Groups C+ and C- were interchanged, also showed second-order unovershadowing and second-order backward blocking. These results, the robustness of second-order retrospective revaluation against the order of the first training phases, can be explained by the extended comparator hypothesis and probabilistic contrast model. However, these results cannot be explained by traditional associative learning models. PMID:19489431

  1. Higher Order Thinking Skills among Secondary School Students in Science Learning

    ERIC Educational Resources Information Center

    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…

  2. Even and Odd Charge Coherent States: Higher-Order Nonclassical Properties and Generation Scheme

    NASA Astrophysics Data System (ADS)

    Duc, Truong Minh; Dinh, Dang Huu; Dat, Tran Quang

    2016-06-01

    We examine the higher-order nonclassical properties of the even and odd charge coherent states as well as proposing a scheme to generate these states whose modes can freely travel in open space. We show that the even and odd charge coherent states exhibit both higher-order antibunching and higher-order squeezing. While the two-mode higher-order antibunching occurs in any order and essentially depends on the charge number, the two-mode higher-order squeezing appears only in the even orders. We also prove that these states are genuinely entangled, and they can be generated by means of cross-Kerr media, beam splitters, phase shifts and threshold detectors. We find that the fidelity and the corresponding success probability to generate these states are dependent on the correlative parameters.

  3. Human Rights and Private Ordering in Virtual Worlds

    NASA Astrophysics Data System (ADS)

    Oosterbaan, Olivier

    This paper explores the application of human rights in (persistent) virtual world environments. The paper begins with describing a number of elements that most virtual environments share and that are relevant for the application of human rights in such a setting; and by describing in a general nature the application of human rights between private individuals. The paper then continues by discussing the application in virtual environments of two universally recognized human rights, namely freedom of expression, and freedom from discrimination. As these specific rights are discussed, a number of more general conclusions on the application of human rights in virtual environments are drawn. The first general conclusion being that, because virtual worlds are private environments, participants are subject to private ordering. The second general conclusion being that participants and non-participants alike have to accept at times that in-world expressions are to an extent private speech. The third general conclusion is that, where participants represent themselves in-world, other participants cannot assume that such in-world representation share the characteristics of the human player; and that where virtual environments contain game elements, participants and non-participants alike should not take everything that happens in the virtual environment at face value or literally, which does however not amount to having to accept a higher level of infringement on their rights for things that happen in such an environment.

  4. Restyling the Humanities Curriculum of Higher Education for Posthuman Times

    ERIC Educational Resources Information Center

    Siddiqui, Jamila R.

    2016-01-01

    The future viability of the humanities in higher education has been broadly debated. Yet, most of these debates are missing an important consideration. The humanities' object of study is the human, an object that some would argue has been replaced in our onto-epistemological systems by the posthuman. In her 2013 book, "The Posthuman,"…

  5. Lagrangian-Hamiltonian unified formalism for autonomous higher order dynamical systems

    NASA Astrophysics Data System (ADS)

    Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso

    2011-09-01

    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.

  6. RNA Duplex Map in Living Cells Reveals Higher-Order Transcriptome Structure.

    PubMed

    Lu, Zhipeng; Zhang, Qiangfeng Cliff; Lee, Byron; Flynn, Ryan A; Smith, Martin A; Robinson, James T; Davidovich, Chen; Gooding, Anne R; Goodrich, Karen J; Mattick, John S; Mesirov, Jill P; Cech, Thomas R; Chang, Howard Y

    2016-05-19

    RNA has the intrinsic property to base pair, forming complex structures fundamental to its diverse functions. Here, we develop PARIS, a method based on reversible psoralen crosslinking for global mapping of RNA duplexes with near base-pair resolution in living cells. PARIS analysis in three human and mouse cell types reveals frequent long-range structures, higher-order architectures, and RNA-RNA interactions in trans across the transcriptome. PARIS determines base-pairing interactions on an individual-molecule level, revealing pervasive alternative conformations. We used PARIS-determined helices to guide phylogenetic analysis of RNA structures and discovered conserved long-range and alternative structures. XIST, a long noncoding RNA (lncRNA) essential for X chromosome inactivation, folds into evolutionarily conserved RNA structural domains that span many kilobases. XIST A-repeat forms complex inter-repeat duplexes that nucleate higher-order assembly of the key epigenetic silencing protein SPEN. PARIS is a generally applicable and versatile method that provides novel insights into the RNA structurome and interactome. VIDEO ABSTRACT. PMID:27180905

  7. Assessment of Higher Order Thinking Skills. Current Perspectives on Cognition, Learning and Instruction

    ERIC Educational Resources Information Center

    Schraw, Gregory, Ed.; Robinson, Daniel H., Ed.

    2011-01-01

    This volume examines the assessment of higher order thinking skills from the perspectives of applied cognitive psychology and measurement theory. The volume considers a variety of higher order thinking skills, including problem solving, critical thinking, argumentation, decision making, creativity, metacognition, and self-regulation. Fourteen…

  8. Family Consumer Sciences Teachers' Use of Technology to Teach Higher Order Thinking Skills

    ERIC Educational Resources Information Center

    Hirose, Beth Erica

    2009-01-01

    Family and consumer sciences (FACS) high school teachers were surveyed on their use of technology to teach higher order thinking skills (HOTS). This study determined if teachers had enough support and training to use technology. Lesson plans were accumulated that required both technology and higher order thinking skills. These lessons were then…

  9. A Lagrangian description of the higher-order Painlevé equations

    NASA Astrophysics Data System (ADS)

    Ghose Choudhury, A.; Guha, Partha; Kudryashov, N. A.

    2012-05-01

    We derive the Lagrangians of the higher-order Painlevé equations using Jacobi's last multiplier technique. Some of these higher-order differential equations display certain remarkable properties like passing the Painlevé test and satisfy the conditions stated by Juráš, thus allowing for a Lagrangian description.

  10. Teaching Higher Order Thinking in the Introductory MIS Course: A Model-Directed Approach

    ERIC Educational Resources Information Center

    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…