Evaluación de la utilidad diagnóstica de la versión española del cuestionario al informador «AD8»☆
Pardo, C. Carnero; de la Vega Cotarelo, R.; Alcalde, S. López; Aparicio, C. Martos; Carrillo, R. Vílchez; Gavilán, E. Mora; Galvin, J.E.
2012-01-01
Introducción El AD8 es un cuestionario al informador breve que puede ser autoaplicado y facilita la identificación de deterioro cognitivo (DC); nuestro objetivo es evaluar la utilidad diagnóstica (UD) de una versión española. Material y métodos Estudio transversal en una muestra clínica de díadas paciente/ informador, 330 sujetos con sospecha de DC o demencia (DEM) y 71 controles. Se ha evaluado la consistencia interna (α de Cronbach) y la validez (correlaciones parciales con estadio GDS, Fototest e índice funcional [IF]). La UD se ha evaluado para no DC vs DC (GDS 3–4) por medio del área bajo la curva ROC (aROC) y se ha considerado mejor punto de corte aquel que hacía máximo el índice de Youden. Resultados En la muestra, 105 no tenían DC, 99 tenían DC sin DEM y 203 DEM. La consistencia interna es alta (α 0,90, IC del 95%, 0,89–0,92), al igual que las correlaciones con GDS (r = 0,72, p < 0,001), Fototest (r = −0,61, p < 0,001) e IF (r = 0,59, p < 0,001). El aROC del AD8 es 0,90 (IC del 95%, 0,86–0,93), sin diferencia significativa con la del Fototest (aROC 0,93, IC del 95%, 0,89–0,96); el mejor punto de corte es 3/4 con sensibilidad de 0,93 (IC del 95%, 0,88–0,96), especificidad de 0,81 (IC del 95%, 0,72–0,88) y el 88,8% de las clasificaciones correctas. El uso conjunto de AD8 y Fototest mejora de forma significativa la UD de ambos (aROC 0,96, IC del 95%, 0,93–0,98, p < 0,05). Conclusiones La versión española del AD8 conserva las cualidades psicométricas y la UD de la versión original; su uso combinado con el Fototest mejora de forma significativa la UD de ambos. PMID:22652137
Cuestionarios | Smokefree Español
Los cuestionarios de Smokefree son una manera divertida de obtener información importante sobre temas relacionados con dejar de fumar, como los síntomas de abstinencia, el estrés y el humo de segunda mano. Responda un cuestionario y mejore su método para dejar de fumar.
Wu, Shuang-Qing
2008-03-28
I present the general exact solutions for nonextremal rotating charged black holes in the Gödel universe of five-dimensional minimal supergravity theory. They are uniquely characterized by four nontrivial parameters: namely, the mass m, the charge q, the Kerr equal rotation parameter a, and the Gödel parameter j. I calculate the conserved energy, angular momenta, and charge for the solutions and show that they completely satisfy the first law of black hole thermodynamics. I also study the symmetry and separability of the Hamilton-Jacobi and the massive Klein-Gordon equations in these Einstein-Maxwell-Chern-Simons-Gödel black hole backgrounds.
Black hole remnant and quantum tunnelling in three-dimensional Gödel spacetime
NASA Astrophysics Data System (ADS)
Li, Hui-Ling; Zu, Xiao-Tao
2015-05-01
Using the modified Dirac equation in a three-dimensional gravity background, we investigate the quantum correction to tunnelling radiation from a Gödel black hole, and discuss the black hole remnant employing fermion's tunnelling. The corrected tunnelling probability is derived, and the modified Hawking temperature is found as well. It is worth emphasizing that, only when the condition j> αω(3 r -- r +) is satisfied, emitting both a mass particle and a massless particle, the remnant of the Gödel black hole may arise.
Moraes, Manoel; Diaz, Marcos E-mail: marcos@astro.iag.usp.br
2009-12-15
The HR Del nova remnant was observed with the IFU-GMOS at Gemini North. The spatially resolved spectral data cube was used in the kinematic, morphological, and abundance analysis of the ejecta. The line maps show a very clumpy shell with two main symmetric structures. The first one is the outer part of the shell seen in H{alpha}, which forms two rings projected in the sky plane. These ring structures correspond to a closed hourglass shape, first proposed by Harman and O'Brien. The equatorial emission enhancement is caused by the superimposed hourglass structures in the line of sight. The second structure seen only in the [O III] and [N II] maps is located along the polar directions inside the hourglass structure. Abundance gradients between the polar caps and equatorial region were not found. However, the outer part of the shell seems to be less abundant in oxygen and nitrogen than the inner regions. Detailed 2.5-dimensional photoionization modeling of the three-dimensional shell was performed using the mass distribution inferred from the observations and the presence of mass clumps. The resulting model grids are used to constrain the physical properties of the shell as well as the central ionizing source. A sequence of three-dimensional clumpy models including a disk-shaped ionization source is able to reproduce the ionization gradients between polar and equatorial regions of the shell. Differences between shell axial ratios in different lines can also be explained by aspherical illumination. A total shell mass of 9 x 10{sup -4} M {sub sun} is derived from these models. We estimate that 50%-70% of the shell mass is contained in neutral clumps with density contrast up to a factor of 30.
Muñoz, Irene; Domínguez, Elena; Hernández, Marta S; Ruiz-Piñero, Marina; Isidro, Guillermo; Mayor-Toranzo, Eduardo; Sotelo, Eva M; Molina, Vicente; Uribe, Fernando; Guerrero-Peral, Ángel L
2015-07-16
Introduccion. El papel patogenico de la personalidad en la migraña no esta definido. Para su estudio se pueden utilizar instrumentos de medida dimensional o categorial, sin que haya tampoco acuerdo acerca del abordaje mas adecuado. Objetivo. Analizar la personalidad de pacientes con migraña cronica desde el punto de vista dimensional y categorial. Pacientes y metodos. Como test categorial utilizamos el cuestionario Salamanca, y, como dimensional, el Minnesota Multiphasic Personality Inventory-2 (MMPI-2). Evaluamos trastornos del animo con la escala de ansiedad y depresion hospitalaria y el impacto de la migraña mediante el Headache Impact Test-6 (HIT-6). Resultados. Incluimos 30 pacientes (26 mujeres), con una edad media de 40,7 ± 9,6 años. Un caso (3,3%) presentaba criterios de depresion, y 4 (13,3%), de ansiedad. En el test Salamanca, los rasgos de personalidad mas frecuentes fueron los integrados en el cluster C: anancastico (n = 28; 93,3%), ansioso (n = 18; 60%) y dependiente (n = 7; 23,3%). En el MMPI-2, 16 pacientes (53,3%) cumplian criterios de hipocondria; 7 (23,3%), de depresion, y 10 (33,3%), de histeria, rasgos integrados en la triada neurotica. Se objetivo una configuracion denominada 'conversiva V'. No hallamos correlacion entre los rasgos de personalidad y el tiempo de migraña cronica, la intensidad medida por el HIT-6 o el uso excesivo de medicacion sintomatica. Conclusiones. En el analisis de la personalidad en la migraña cronica destaca, desde el punto de vista dimensional, el neuroticismo, y respecto al categorial, el rasgo obsesivo-compulsivo o anancastico. Es necesario el estudio de series mas extensas y la comparacion con pacientes con migraña episodica y poblacion control.
López-Cepero, Javier; Fabelo, Humberto Eduardo; Rodríguez-Franco, Luis; Rodríguez-Díaz, F Javier
2016-01-01
This study provides psychometric information for the Dating Violence Questionnaire (DVQ), an instrument developed to assess intimate partner victimization among adolescents and youths. This instrument, an English version of Cuestionario de Violencia de Novios, assesses both frequency and discomfort associated with 8 types of abuse (detachment, humiliation, sexual, coercion, physical, gender-based, emotional punishment, and instrumental). Participant included 859 U.S. students enrolled in undergraduate psychology courses in a mid-Atlantic university (M = 19 years; SD = 1.5 years). One-third of the participants were males, and two-thirds were females. Regarding racial identity, around 55% of participants identified themselves as White, 22% as African American, 12% as Asian, whereas 11% selected other identities. Around 9% of participants identified themselves as Hispanic. Confirmatory factor analysis shows that the DVQ achieved adequate goodness-of-fit indexes for the original eight-factor model (X(2)/df <5; root mean square error of approximation [RMSEA] <.080), as well as higher parsimony when compared to simpler alternative models. The 8 scales demonstrated acceptable internal consistency indexes (α >.700), surpassing those found in the original Spanish validation. Descriptive analysis suggests higher victimization experience on subtle aggressions (detachment, coercion, and emotional punishment), with overt abuses (physical, instrumental) obtaining the smallest means; these findings were similar across gender, race identity, and ethnicity. Results of this validation study encourage the inclusion of DVQ in both research and applied contexts.
Soutello, Ana Lúcia Soares; Rodrigues, Roberta Cunha Matheus; Jannuzzi, Fernanda Freire; Spana, Thaís Moreira; Gallani, Maria Cecília Bueno Jayme; Nadruz Junior, Wilson
2011-01-01
This study aimed to evaluate the feasibility, acceptability, ceiling and floor effects, reliability, and convergent construct validity of the Brazilian version of the Mini Cuestionario de Calidad de Vida en la Hipertensión Arterial (MINICHAL). The study included 200 hypertensive outpatients in a university hospital and a primary healthcare unit. The MINICHAL was applied in 3.0 (± 1.0) minutes with 100% of the items answered. A "ceiling effect" was observed in both dimensions and in the total score, as well as evidence of measurement stability (ICC=0.74). The convergent validity was confirmed by significant positive correlations between similar dimensions of the MINICHAL and the SF-36, and significant negative correlations with the Minnesota Living with Heart Failure Questionnaire - MLHFQ, however, correlations between dissimilar constructs were also observed. It was concluded that the Brazilian version of the MINICHAL presents evidence of reliability and validity when applied to hypertensive outpatients.
Gödel universe from string theory
NASA Astrophysics Data System (ADS)
Li, Shou-Long; Feng, Xing-Hui; Wei, Hao; Lü, H.
2017-05-01
The Gödel universe is a direct product of a line and a three-dimensional spacetime we call G_α . In this paper, we show that the Gödel metrics can arise as exact solutions in Einstein-Maxwell-Axion, Einstein-Proca-Axion, or Freedman-Schwarz gauged supergravity theories. The last option allows us to embed the Gödel universe in string theory. The ten-dimensional spacetime is a direct product of a line and the nine-dimensional one of an S^3× S^3 bundle over G_α , and it can be interpreted as some decoupling limit of the rotating D1/D5/D5 intersection. For some appropriate parameter choice, the nine-dimensional metric becomes an AdS_3× S^3 bundle over squashed 3-sphere. We also study the properties of the Gödel black holes that are constructed from the double Wick rotations of the Gödel metrics.
Green, Daniel; Lawrence, Albion; McGreevy, John; Morrison, David R.; Silverstein, Eva; /SLAC /Stanford U., Phys. Dept.
2007-05-18
We show that string theory on a compact negatively curved manifold, preserving a U(1)b1 winding symmetry, grows at least b1 new effective dimensions as the space shrinks. The winding currents yield a ''D-dual'' description of a Riemann surface of genus h in terms of its 2h dimensional Jacobian torus, perturbed by a closed string tachyon arising as a potential energy term in the worldsheet sigma model. D-branes on such negatively curved manifolds also reveal this structure, with a classical moduli space consisting of a b{sub 1}-torus. In particular, we present an AdS/CFT system which offers a non-perturbative formulation of such supercritical backgrounds. Finally, we discuss generalizations of this new string duality.
[Sexual attraction: its dimensionality].
Fernández, Juan; Quiroga, María Angeles; Rodríguez, Antonio
2006-08-01
The purpose of this research was to develop a new Sexual Attraction Questionnaire (SAQ) [Cuestionario de Atracción Sexual, CAS]. The goal was to determine whether sexual attraction could be represented as two different clusters (Attraction to men and Attraction to women), which would imply two negatively correlated factors or a bipolar one. Three studies were carried out with 182, 118, and 425 participants, respectively. Cluster and exploratory factor analyses were performed. The results obtained show satisfactory psychometric properties for the SAQ, the two clusters, and the two predicted negatively related factors or the bipolar factor. Results are discussed in the context of the different conceptions of sexual attraction and the fourfold typology: attracted to both sexes, to men, to women, or to neither sex.
Three-dimensional magnetospheric equilibrium with isotropic pressure
Cheng, C.Z.
1995-05-01
In the absence of the toroidal flux, two coupled quasi two-dimensional elliptic equilibrium equations have been derived to describe self-consistent three-dimensional static magnetospheric equilibria with isotropic pressure in an optimal ({Psi},{alpha},{chi}) flux coordinate system, where {Psi} is the magnetic flux function, {chi} is a generalized poloidal angle, {alpha} is the toroidal angle, {alpha} = {phi} {minus} {delta}({Psi},{phi},{chi}) is the toroidal angle, {delta}({Psi},{phi},{chi}) is periodic in {phi}, and the magnetic field is represented as {rvec B} = {del}{Psi} {times} {del}{alpha}. A three-dimensional magnetospheric equilibrium code, the MAG-3D code, has been developed by employing an iterative metric method. The main difference between the three-dimensional and the two-dimensional axisymmetric solutions is that the field-aligned current and the toroidal magnetic field are finite for the three-dimensional case, but vanish for the two-dimensional axisymmetric case. With the same boundary flux surface shape, the two-dimensional axisymmetric results are similar to the three-dimensional magnetosphere at each local time cross section.
El moho forma parte del medio ambiente natural. Afuera del hogar, el moho juega un papel en la naturaleza al desintegrar materias organicas tales como las hojas que se han caido o los arboles muertos. El moho puede crecer adentro del hogar cuando las espor
Fernández-Prada, María; González-Cabrera, Joaquín; Iribar-Ibabe, Concepción; Peinado, José María
2017-01-01
Evaluar el estrés, los riesgos psicosociales asociados al puesto de trabajo y el burnout en un grupo de residentes en el servicio de urgencias; y analizar qué variables se relacionan y predicen mejor el burnout. Estudio analítico y transversal en el que han participado 42 médicos internos residentes que hacen guardias en el servicio de urgencias del Hospital Universitario San Cecilio, Granada. Se han utilizado la versión adaptada al español de la Perceived Stress Scale para evaluar el estrés, el Maslach Burnout Inventory (MBI) para valorar el desgaste profesional, y el cuestionario adaptado y baremado para la autoevaluación de riesgos psicosociales en el trabajo (CopSoQ-ISTAS21). El 78% de los residentes evaluados se encuentra en la categoría desfavorable o intermedia en todas las dimensiones del CopSoQ-ISTAS21, y destaca que el 90% presenta una puntuación desfavorable en exigencias psicológicas. Además, en el MBI el 45% presenta conjuntamente un alto agotamiento emocional y una elevada despersonalización. La dimensión de exigencias psicológicas del ISTAS21 (b = 0.393; p < 0.003) y las puntuaciones de estrés (b = 0.451; p < 0.001) predicen significativamente el agotamiento emocional (r(2) = 0.443). Por último, el 38% ha sufrido una amenaza/agresión en el servicio de urgencias. La situación de los residentes parece perjudicial para su desempeño profesional debido a los altos riesgos psicosociales asociados al puesto de trabajo. Las exigencias psicológicas se proponen como un importante predictor del burnout. Se recomiendan intervenciones psicológicas y estructurales con las que mejorar la situación de los residentes que realizan guardias en el servicio de urgencias. To study the stress, the psychosocial risks associated to the job and the burnout, in a group of junior doctors working at the emergency ward; and to analyze what of those variables could predict and are better related with burnout. Cross-sectional study, with a sample of 42 junior
Bayesian supervised dimensionality reduction.
Gönen, Mehmet
2013-12-01
Dimensionality reduction is commonly used as a preprocessing step before training a supervised learner. However, coupled training of dimensionality reduction and supervised learning steps may improve the prediction performance. In this paper, we introduce a simple and novel Bayesian supervised dimensionality reduction method that combines linear dimensionality reduction and linear supervised learning in a principled way. We present both Gibbs sampling and variational approximation approaches to learn the proposed probabilistic model for multiclass classification. We also extend our formulation toward model selection using automatic relevance determination in order to find the intrinsic dimensionality. Classification experiments on three benchmark data sets show that the new model significantly outperforms seven baseline linear dimensionality reduction algorithms on very low dimensions in terms of generalization performance on test data. The proposed model also obtains the best results on an image recognition task in terms of classification and retrieval performances.
Infinite dimensional matrix algebras
NASA Astrophysics Data System (ADS)
Bordemann, M.; Hoppe, J.; Schaller, P.
1989-11-01
To each (finite dimensional) Lie algebra g we associate a class L λ(g) of infinite dimensional Lie algebras, induced by representations D λ(g). We show that in the case of sl(2, C) one obtains a series of pairwise non-isomorphic infinite dimensional Lie algebras depending continuously on a complex parameter λ. We connect this method with previous results on the relation between Diff AS 2 and su( N), and comment on a recent conjecture concerning higher spin algebras, and (2 + 1)-dimensional gravity.
Three dimensional strained semiconductors
Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui
2016-11-08
In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.
Dimensional comparison theory.
Möller, Jens; Marsh, Herb W
2013-07-01
Although social comparison (Festinger, 1954) and temporal comparison (Albert, 1977) theories are well established, dimensional comparison is a largely neglected yet influential process in self-evaluation. Dimensional comparison entails a single individual comparing his or her ability in a (target) domain with his or her ability in a standard domain (e.g., "How good am I in math compared with English?"). This article reviews empirical findings from introspective, path-analytic, and experimental studies on dimensional comparisons, categorized into 3 groups according to whether they address the "why," "with what," or "with what effect" question. As the corresponding research shows, dimensional comparisons are made in everyday life situations. They impact on domain-specific self-evaluations of abilities in both domains: Dimensional comparisons reduce self-concept in the worse off domain and increase self-concept in the better off domain. The motivational basis for dimensional comparisons, their integration with recent social cognitive approaches, and the interdependence of dimensional, temporal, and social comparisons are discussed.
Kubota, Kazumi; Shimazu, Akihito; Kawakami, Norito; Takahashi, Masaya; Nakata, Akinori; Schaufeli, Wilmar B.
2016-01-01
Objetivo El objetivo de este estudio es demostrar la distinción entre engagement y trabajolismo, estudiando su relación con la calidad del sueño y el desempeño laboral. Método Un total de 447 enfermeras de 3 hospitales de Japón fueron entrevistadas mediante un cuestionario autoadministrado que incluía la escala Utrecht (UWES, Utrecht Work Engagement Scale), la Escala de Adicción al Trabajo Holandesa (DUWAS, Dutch Workaholism Scale), preguntas sobre la calidad del sueño (7 ítems) con respecto a (1) dificultad para conciliar el sueño, (2) dificultad para mantener el sueño, (3) despertar temprano por la mañana, (4) dormirse o tomar siestas durante el día, (5) somnolencia diurna excesiva en el trabajo, (6) dificultad para despertarse por la mañana, y (7) despertar cansado en la mañana, y el Cuestionario sobre Salud y Desempeño (CSD) de la Organización Mundial de la Salud. Resultados Los modelos de ecuaciones estructurales demostraron que el engagement se relaciona positivamente con la calidad del sueño y el rendimiento laboral, mientras que el trabajolismo tiene una relación negativa con la calidad del sueño y el desempeño laboral. Conclusión Los resultados indican que el engagement y el trabajolismo son conceptualmente diferentes. El primero tiene una connotación positiva, mientras que el segundo se asocia de manera negativa al bienestar (buena calidad del sueño y buen rendimiento en el trabajo). PMID:26752805
On some structure results for Gödel-type spacetimes
NASA Astrophysics Data System (ADS)
Plaue, Matthias; Scherfner, Mike
2016-12-01
In this paper, we prove structure results on Gödel-type spacetimes, which we understand as stationary charged perfect fluid solutions of the Einstein-Maxwell equations with geodesic flow. Given in a standard product form, we investigate relations between the vorticity and the geometry of the fiber. For the four dimensional case in particular, we classify the Gödel-type spacetimes with constant vorticity scalar. We give a complete list of the solutions, which provides a generalization of an observation by Gödel, proved later by Ozsváth: The Gödel spacetime and Einstein's static universe are the only stationary Λ-dust solutions of Einstein's equations with positive energy density that are spatially homogeneous.
Three-Dimensional Complex Variables
NASA Technical Reports Server (NTRS)
Martin, E. Dale
1988-01-01
Report presents new theory of analytic functions of three-dimensional complex variables. While three-dimensional system subject to more limitations and more difficult to use than the two-dimensional system, useful in analysis of three-dimensional fluid flows, electrostatic potentials, and other phenomena involving harmonic functions.
Ohm-Kirchhoff's law and screening in two-dimensional electron liquid
NASA Astrophysics Data System (ADS)
Mareš, J. J.; Krištofik, J.; Hubík, P.
2002-01-01
Analysing some experimental facts, a modification of Ohm-Kirchhoff's constitutive transport relation containing diffusion-related term was established. Simultaneous application of this formula and basic ideas of stochastic electrodynamics to a two-dimensional electron liquid (2DEL) enabled us to obtain relations coupling screening and transport properties of the 2DEL, which may be useful, e.g. for the interpretation of low-temperature magneto-capacitance experiments.
Higher dimensional massive bigravity
NASA Astrophysics Data System (ADS)
Do, Tuan Q.
2016-08-01
We study higher-dimensional scenarios of massive bigravity, which is a very interesting extension of nonlinear massive gravity since its reference metric is assumed to be fully dynamical. In particular, the Einstein field equations along with the following constraint equations for both physical and reference metrics of a five-dimensional massive bigravity will be addressed. Then, we study some well-known cosmological spacetimes such as the Friedmann-Lemaitre-Robertson-Walker, Bianchi type I, and Schwarzschild-Tangherlini metrics for the five-dimensional massive bigravity. As a result, we find that massive graviton terms will serve as effective cosmological constants in both physical and reference sectors if a special scenario, in which reference metrics are chosen to be proportional to physical ones, is considered for all mentioned metrics. Thanks to the constancy property of massive graviton terms, consistent cosmological solutions will be figured out accordingly.
NASA Astrophysics Data System (ADS)
D'Antona, F.
1995-03-01
Contents: 1. Introduzione. 2. La nucleosintesi del Big Bang. 3. Il litio nelle stelle di popolazione II. 4. I modelli stellari standard. 5. Il litio negli ammassi aperti. 6. Meccanismi di distruzione "non standard". 7. I modelli non-standard applicati alla popolazione II. 8. L'evoluzione Galattica del litio. 9. Quali stelle producono litio? 10. Il litio come elemento chiave per dare un nome agli oggetti stellari più minuscoli. 11. Conclusioni.
Three-dimensional nanomagnetism
Fernandez-Pacheco, Amalio; Streubel, Robert; Fruchart, Olivier; ...
2017-06-09
Magnetic nanostructures are being developed for use in many aspects of our daily life, spanning areas such as data storage, sensing and biomedicine. Whereas patterned nanomagnets are traditionally two-dimensional planar structures, recent work is expanding nanomagnetism into three dimensions; a move triggered by the advance of unconventional synthesis methods and the discovery of new magnetic effects. In three-dimensional nanomagnets more complex magnetic configurations become possible, many with unprecedented properties. Here we review the creation of these structures and their implications for the emergence of new physics, the development of instrumentation and computational methods, and exploitation in numerous applications.
Three dimensional quantum chromodynamics
NASA Astrophysics Data System (ADS)
Ferretti, G.; Rajeev, S. G.; Yang, Z.
1992-02-01
The subject of this talk is the study of the low energy behavior of three (2+1) dimensional Quantum Chromodynamics. We show the existence of a phase where parity is unbroken and the flavor group U(2n) is broken into a subgroup U(n)×U(n). We derive the low energy effective action for the theory and show that it has solitonic excitations with Fermi statistic, to be identified with the three dimensional ``baryon''. Finally, we study the current algebra for this effective action and we find a co-homologically nontrivial generalization of Kac-Moody algebras to three dimension.
Three-dimensional nanomagnetism
NASA Astrophysics Data System (ADS)
Fernández-Pacheco, Amalio; Streubel, Robert; Fruchart, Olivier; Hertel, Riccardo; Fischer, Peter; Cowburn, Russell P.
2017-06-01
Magnetic nanostructures are being developed for use in many aspects of our daily life, spanning areas such as data storage, sensing and biomedicine. Whereas patterned nanomagnets are traditionally two-dimensional planar structures, recent work is expanding nanomagnetism into three dimensions; a move triggered by the advance of unconventional synthesis methods and the discovery of new magnetic effects. In three-dimensional nanomagnets more complex magnetic configurations become possible, many with unprecedented properties. Here we review the creation of these structures and their implications for the emergence of new physics, the development of instrumentation and computational methods, and exploitation in numerous applications.
Espectroscopia del Cometa Halley
NASA Astrophysics Data System (ADS)
Naranjo, O.; Fuenmayor, F.; Ferrin, L.; Bulka, P.; Mendoza, C.
1987-05-01
Se reportan observaciones espectroscópicas del cometa Halley. Los espectros fueron tomados usando el espectrógrafo del telescopio reflector de 1 metro del Observatorio Nacional de Venezuela. Se utilizó óptica azul, con una red de difracción de 600 lineas/min, obteniéndose una dispersión de 74.2 A/mm y una resolución de 2.5 A, en el rango espectral de 3500 a 6500 A. Seis placas fueron tomadas con emulsión IIa-O y dos con IIa-D. Los tiempos de exposición fueron entre 10 y 150 minutos. El cometa se encontraba entre 0.70 y 1.04 UA del Sol, y entre 1.28 y 0.73 UA de la Tierra. Las emisiones más prominentes en el espectro, son las del CN, C2, y C3. Otras emisiones detectadas corresponden a CH, NH2 y Na. Los espectros muestran un fuerte continuo, indicando un contenido significativo de polvo. Se detectó mayor intensidad del contínuo, en la dirección anti solar, lo cual es evidencia de la cola de polvo.
Dimensional Regularization is Generic
NASA Astrophysics Data System (ADS)
Fujikawa, Kazuo
The absence of the quadratic divergence in the Higgs sector of the Standard Model in the dimensional regularization is usually regarded to be an exceptional property of a specific regularization. To understand what is going on in the dimensional regularization, we illustrate how to reproduce the results of the dimensional regularization for the λϕ4 theory in the more conventional regularization such as the higher derivative regularization; the basic postulate involved is that the quadratically divergent induced mass, which is independent of the scale change of the physical mass, is kinematical and unphysical. This is consistent with the derivation of the Callan-Symanzik equation, which is a comparison of two theories with slightly different masses, for the λϕ4 theory without encountering the quadratic divergence. In this sense the dimensional regularization may be said to be generic in a bottom-up approach starting with a successful low energy theory. We also define a modified version of the mass independent renormalization for a scalar field which leads to the homogeneous renormalization group equation. Implications of the present analysis on the Standard Model at high energies and the presence or absence of SUSY at LHC energies are briey discussed.
Prevalencia y tamizaje del Trastorno por Déficit de Atención con Hiperactividad en Costa Rica
Weiss, Nicholas T.; Schuler, Jovita; Monge, Silvia; McGough, James J.; Chavira, Denise; Bagnarello, Monica; Herrera, Luis Diego; Mathews, Carol A.
2015-01-01
Resumen La investigación tuvo como propósito estimar la prevalencia del Trastorno por Déficit de Atención con Hiperactividad (TDAH) en Costa Rica y determinar si la versión en español del cuestionario Swanson Nolan and Pelham Scale IV (SNAP-IV) es un instrumento de tamizaje útil en una población de niños y niñas escolares costarricenses. El instrumento fue entregado a padres y maestros de 425 niños entre 5 y 13 años de edad (promedio = 8.8). Todos fueron evaluados con el instrumento Swanson, Kotkin, Agler, M-Flynn and Pelham Scale (SKAMP). Su diagnóstico fue confirmado con una entrevista clínica. La sensibilidad y la especificidad del SNAP-IV fueron evaluadas como predictores de criterios de diagnóstico según el DSM-IV. La prevalencia puntual en la muestra del TDAH fue del 5%. El tamizaje más preciso lo hizo el SNAP-IV completado por el maestro en un corte de 20%, con una sensibilidad de 96% y una especificidad de un 82%. La sensibilidad de los instrumentos completados por los padres fue más baja que aquella de los maestros. El SNAP-IV completado por las maestras con un corte aislando el 20% de los mayores puntajes categorizó correctamente a un 87% de los sujetos. PMID:22432094
Methods of Two-Dimensional Spectroscopy
NASA Astrophysics Data System (ADS)
Kneer, F.
One of the main fields of solar research is the study of dynamic processes of small-scale structures. For this purpose, time sequences of spectroscopic and polarimetric information in two spatial dimensions with best achievable quality are needed. The present contribution deals with the ways to obtain images in small wavelength bands. Among these are image scanners and the MSDP (Multi-Channel Subtractive Double Pass Spectrograph). Further potential instruments are scanning Fabry-Perot interferometers (FPI). The principles of such instruments are discussed. The results obtained hitherto from the FPI in the Vacuum Tower Telescope at the Observatorio del Teide are promising. Small-band, two-dimensional spectroscopy with spatial resolution close to the telescopic diffraction limit seems possible in the near future.
Four-Dimensional Entropy from Three-Dimensional Gravity.
Carlip, S
2015-08-14
At the horizon of a black hole, the action of (3+1)-dimensional loop quantum gravity acquires a boundary term that is formally identical to an action for three-dimensional gravity. I show how to use this correspondence to obtain the entropy of the (3+1)-dimensional black hole from well-understood conformal field theory computations of the entropy in (2+1)-dimensional de Sitter space.
Dimensional characteristics of low-dimensional structures
NASA Astrophysics Data System (ADS)
Blood, Peter
2000-07-01
The purpose of this paper is to examine the dimensional aspects of the optical properties of quantum well and dot systems, without assuming that the carriers are localized to the geometrical extent of the confining potential. We show that optical absorption normal to the plane of a well cannot be expressed as an absorption coefficient but should be specified as a fraction of light transmitted or absorbed per well. The modal gain for light propagating along the plane of a well does not scale with well width and the variation of the material gain inversely proportional to the well width is a consequence of the definition of the confinement factor and has no independent physical significance. Optical absorption by quantum dots should be expressed as a cross section per dot. The radiative recombination rate is correctly expressed in terms of a 2D recombination coefficient and use of an equivalent 3D coefficient introduces an artificial dependence on well width which can lead to errors in the comparison of quantum well systems.
High three dimensional thermoelectric performance from low dimensional bands
Singh, David J; Chen, Xin; Parker, David S
2013-01-01
Reduced dimensionality has long been regarded as an important strategy for increasing thermoelectric performance, for example in superlattices and other engineered structures. Here we point out and illustrate by examples that three dimensional bulk materials can be made to behave as if they were two dimensional from the point of view of thermoelectric performance. Implications for the discovery of new practical thermoelectrics are discussed.
Kerstein, A.R.
1996-12-31
One-Dimensional Turbulence is a new turbulence modeling strategy involving an unsteady simulation implemented in one spatial dimension. In one dimension, fine scale viscous and molecular-diffusive processes can be resolved affordably in simulations at high turbulence intensity. The mechanistic distinction between advective and molecular processes is thereby preserved, in contrast to turbulence models presently employed. A stochastic process consisting of mapping {open_quote}events{close_quote} applied to a one-dimensional velocity profile represents turbulent advection. The local event rate for given eddy size is proportional to the velocity difference across the eddy. These properties cause an imposed shear to induce an eddy cascade analogous in many respects to the eddy cascade in turbulent flow. Many scaling and fluctuation properties of self-preserving flows, and of passive scalars introduced into these flows, are reproduced.
NASA Astrophysics Data System (ADS)
Feinsilver, Philip; Schott, René
2009-09-01
We discuss topics related to finite-dimensional calculus in the context of finite-dimensional quantum mechanics. The truncated Heisenberg-Weyl algebra is called a TAA algebra after Tekin, Aydin and Arik who formulated it in terms of orthofermions. It is shown how to use a matrix approach to implement analytic representations of the Heisenberg-Weyl algebra in univariate and multivariate settings. We provide examples for the univariate case. Krawtchouk polynomials are presented in detail, including a review of Krawtchouk polynomials that illustrates some curious properties of the Heisenberg-Weyl algebra, as well as presenting an approach to computing Krawtchouk expansions. From a mathematical perspective, we are providing indications as to how to implement infinite terms Rota's 'finite operator calculus'.
Five-dimensional crystallography
Schmidt, Marius; Graber, Tim; Henning, Robert; Srajer, Vukica
2010-01-01
A method for determining a comprehensive chemical kinetic mechanism in macromolecular reactions is presented. The method is based on five-dimensional crystallography, where, in addition to space and time, temperature is also taken into consideration and an analysis based on singular value decomposition is applied. First results of such a time-resolved crystallographic study are presented. Temperature-dependent time-resolved X-ray diffraction measurements were conducted on the newly upgraded BioCARS 14-ID-B beamline at the Advanced Photon Source and aimed at elucidating a comprehensive kinetic mechanism of the photoactive yellow protein photocycle. Extensive time series of crystallographic data were collected at two temperatures, 293 K and 303 K. Relaxation times of the reaction extracted from these time series exhibit measurable differences for the two temperatures, hence demonstrating that five-dimensional crystallography is feasible. PMID:20164643
The dimensionality of discourse
Doxas, Isidoros; Dennis, Simon; Oliver, William L.
2010-01-01
The paragraph spaces of five text corpora, of different genres and intended audiences, in four different languages, all show the same two-scale structure, with the dimension at short distances being lower than at long distances. In all five cases the short-distance dimension is approximately eight. Control simulations with randomly permuted word instances do not exhibit a low dimensional structure. The observed topology places important constraints on the way in which authors construct prose, which may be universal. PMID:20194761
2005-06-30
possible responses that were worded either positively or negatively for mistrust. Using confirmatory factor analysis , the authors extracted one general...validity of their measure. Lastly, Omodei and McLennan (2000) explored the dimensionality of their measure by using confirmatory factor analysis to...confirmatory factor analysis showed these items to fit the two construct solution. That is, the model depicting trust and suspicion as two distinct
The dimensionality of discourse.
Doxas, Isidoros; Dennis, Simon; Oliver, William L
2010-03-16
The paragraph spaces of five text corpora, of different genres and intended audiences, in four different languages, all show the same two-scale structure, with the dimension at short distances being lower than at long distances. In all five cases the short-distance dimension is approximately eight. Control simulations with randomly permuted word instances do not exhibit a low dimensional structure. The observed topology places important constraints on the way in which authors construct prose, which may be universal.
2014-09-26
linear electronic specific heat disappears in strong magnetic fields if Landau levels are not broadened. Thus, the amplitude of the magnetothermal...Molec. Crys. Liq. Crys. 121, 169 (1984). In consideration of mixing of low-lying Landau levels, the magneto- conductance of two-dimensional electrons...and narrowing can be explained when the Landau level filling factor v is larger than 1. Actually, we have shown that the resonance phenomena are
Three Dimensional Dirac Semimetals
NASA Astrophysics Data System (ADS)
Zaheer, Saad
2014-03-01
Dirac points on the Fermi surface of two dimensional graphene are responsible for its unique electronic behavior. One can ask whether any three dimensional materials support similar pseudorelativistic physics in their bulk electronic spectra. This possibility has been investigated theoretically and is now supported by two successful experimental demonstrations reported during the last year. In this talk, I will summarize the various ways in which Dirac semimetals can be realized in three dimensions with primary focus on a specific theory developed on the basis of representations of crystal spacegroups. A three dimensional Dirac (Weyl) semimetal can appear in the presence (absence) of inversion symmetry by tuning parameters to the phase boundary separating a bulk insulating and a topological insulating phase. More generally, we find that specific rules governing crystal symmetry representations of electrons with spin lead to robust Dirac points at high symmetry points in the Brillouin zone. Combining these rules with microscopic considerations identifies six candidate Dirac semimetals. Another method towards engineering Dirac semimetals involves combining crystal symmetry and band inversion. Several candidate materials have been proposed utilizing this mechanism and one of the candidates has been successfully demonstrated as a Dirac semimetal in two independent experiments. Work carried out in collaboration with: Julia A. Steinberg, Steve M. Young, J.C.Y. Teo, C.L. Kane, E.J. Mele and Andrew M. Rappe.
Procesamiento Digital de Imagenes del Cometa Halley
NASA Astrophysics Data System (ADS)
Ferrin, L.; Fuenmayor, F.; Naranjo, O.; Bulka, P.; Mendoza, C.
1987-05-01
Se reportan observaciones fotográficas del cometa Halley, obtenidas con los telescopios Schmidt de 1-m del CIDA, y de 35 cms de la ULA. Se hicieron exposiciones desde 2 segundos a 30 minutos y se utilizaron emulsiones IIa-O, 103a-F, y 103a-D, guladas manualmente 0 automaticámente. Las imágenes fueron digitalizadas con el microdensitómetro PDS, y procesadas con el sistema HACIENDA del CCIBM. Se experimentó con la Transformada de Fourier en dos dimensiones, y con la aplicación de filtros de paso alto y bajo. Se encontró que el metodo de "autocorrelación" es el mejor para separar "la vegetación" de "la montaña". Se aplicaron diversas técnicas a fin de cubrir ambos extremos: a) enfatizar detalles débiles en la cola, y b) penetrar en las regiones más intensas de la coma. Se lograron ambos objetivos. Detalles en la cola permitieron determinar velocidades de propagación de unos 50 a 90 kms/ seg. Se pudieron detectar no menos de tres perturbaciones en "Y", y una en 5? Co de Cisne). Se cree que las primeras están asociadas a eventos de desconexión. Se puede separar la cola de gas de la de polvo. Las fotos de color permiten enfatizar diferentes regiones espectrales con mayor claridad aún. El "balance" del color puede ser hecho con la computadora.
One-Dimensionality and Whiteness
ERIC Educational Resources Information Center
Calderon, Dolores
2006-01-01
This article is a theoretical discussion that links Marcuse's concept of one-dimensional society and the Great Refusal with critical race theory in order to achieve a more robust interrogation of whiteness. The author argues that in the context of the United States, the one-dimensionality that Marcuse condemns in "One-Dimensional Man" is best…
One-Dimensionality and Whiteness
ERIC Educational Resources Information Center
Calderon, Dolores
2006-01-01
This article is a theoretical discussion that links Marcuse's concept of one-dimensional society and the Great Refusal with critical race theory in order to achieve a more robust interrogation of whiteness. The author argues that in the context of the United States, the one-dimensionality that Marcuse condemns in "One-Dimensional Man" is best…
Multi-dimensional conversion to the ion-hybrid mode
Tracy, E.R.; Kaufman, A.N.; Brizard, A.J.; Morehead, J.J.
1996-12-31
We first demonstrate that the dispersion matrix for linear conversion of a magnetosonic wave to an ion-hybrid wave (as in a D-T plasma) can be congruently transformed to Friedland`s normal form. As a result, this conversion can be represented as a two-step process of successive linear conversions in phase space. We then proceed to study the multi-dimensional case of tokamak geometry. After fourier transforming the toroidal dependence, we deal with the two-dimensional poloidal xy-plane and the two-dimensional k{sub x}k{sub y}-plane, forming a four-dimensional phase space. The dispersion manifolds for the magnetosonic wave [D{sub M} (x, k) = 0] and the ion-hybrid wave [D{sub H} (x, k) = 0] are each three-dimensional. (Their intersection, on which mode conversion occurs, is two-dimensional.) The incident magnetosonic wave (radiated by an antenna) is a two-dimensional set of rays (a lagrangian manifold): k(x) = {del}{theta}(x), with {theta}(x) the phase of the magnetosonic wave. When these rays pierce the ion-hybrid dispersion manifold, they convert to a set of ion-hybrid rays. Then, when those rays intersect the magnetosonic dispersion manifold, they convert to a set of {open_quotes}reflected{close_quotes} magnetosonic rays. This set of rays is distinct from the set of incident rays that have been reflected by the inner surface of the tokamak plasma. As a result, the total destructive interference that can occur in the one-dimensional case may become only partial. We explore the implications of this startling phenomenon both analytically and geometrically.
Three-dimensional ultrasound scanning.
Fenster, Aaron; Parraga, Grace; Bax, Jeff
2011-08-06
The past two decades have witnessed developments of new imaging techniques that provide three-dimensional images about the interior of the human body in a manner never before available. Ultrasound (US) imaging is an important cost-effective technique used routinely in the management of a number of diseases. However, two-dimensional viewing of three-dimensional anatomy, using conventional two-dimensional US, limits our ability to quantify and visualize the anatomy and guide therapy, because multiple two-dimensional images must be integrated mentally. This practice is inefficient, and may lead to variability and incorrect diagnoses. Investigators and companies have addressed these limitations by developing three-dimensional US techniques. Thus, in this paper, we review the various techniques that are in current use in three-dimensional US imaging systems, with a particular emphasis placed on the geometric accuracy of the generation of three-dimensional images. The principles involved in three-dimensional US imaging are then illustrated with a diagnostic and an interventional application: (i) three-dimensional carotid US imaging for quantification and monitoring of carotid atherosclerosis and (ii) three-dimensional US-guided prostate biopsy.
Three-dimensional ultrasound scanning
Fenster, Aaron; Parraga, Grace; Bax, Jeff
2011-01-01
The past two decades have witnessed developments of new imaging techniques that provide three-dimensional images about the interior of the human body in a manner never before available. Ultrasound (US) imaging is an important cost-effective technique used routinely in the management of a number of diseases. However, two-dimensional viewing of three-dimensional anatomy, using conventional two-dimensional US, limits our ability to quantify and visualize the anatomy and guide therapy, because multiple two-dimensional images must be integrated mentally. This practice is inefficient, and may lead to variability and incorrect diagnoses. Investigators and companies have addressed these limitations by developing three-dimensional US techniques. Thus, in this paper, we review the various techniques that are in current use in three-dimensional US imaging systems, with a particular emphasis placed on the geometric accuracy of the generation of three-dimensional images. The principles involved in three-dimensional US imaging are then illustrated with a diagnostic and an interventional application: (i) three-dimensional carotid US imaging for quantification and monitoring of carotid atherosclerosis and (ii) three-dimensional US-guided prostate biopsy. PMID:22866228
RASTREO DEL CANCER COLORRECTAL CONOCIMIENTO Y ACTITUD DE LA POBLACION
CASAL, ENRIQUE R.; VELAZQUEZ, ELIZABETH N.; MEJIA, RAUL M.; CUNEO, ALDO; PEREZ-STABLE, ELISEO J.
2014-01-01
Resumen El rastreo de cáncer colorrectal (CCR) cuenta con fuertes evidencias en su favor. Datos preliminares indican que a pesar de ello no se lleva a cabo con la frecuencia adecuada. Se intenta aquí determinar, dentro de un Sistema de Salud que cuenta con los recursos necesarios, los elementos que facilitan o generan barreras para concretar esta práctica preventiva, cuántos individuos lo ponen en práctica y qué predice esta conducta. Se realizó una encuesta telefónica a los afiliados de una Obra Social de empleados de la Universidad de Buenos Aires, de los que 132 completaron el cuestionario (tasa de respuesta 70%). Los elementos considerados facilitadores del rastreo obtuvieron respuestas afirmativas en el 64 a 97%, mientras que los que definían barreras un 11 a 27%. En este último grupo, una categoría diferenciada la constituía el miedo a los efectos adversos: 39%, y el sentimiento de vergüenza relacionado con los procedimientos: 30%. Un 33% de los encuestados tenían hecho un método de rastreo, mayoritariamente de sangre oculta (27), sigmoideoscopía (11) y colonoscopía (20). Una mayoría afirmó que “se haría el procedimiento si el médico se lo recomendara” (95%), o “no se lo haría excepto que su médico se lo aconseje” (87%). Contestar afirmativamente que “los médicos hacen lo mejor para los pacientes” se asoció con haberse hecho un método de rastreo de CCR, OR 1.55 (IC 95%: 1.02-2.37) p: 0.04. El grupo de individuos estudiado parece bien predispuesto para el rastreo del CCR, la recomendación médica sería aquí un determinante prominente para ponerlo en práctica. PMID:19414294
NASA Astrophysics Data System (ADS)
Olano, C.; Lemarchand, G.; Sanz, A. J.; Bava, J. A.
El objetivo principal de este proyecto consiste en el estudio de la distribución y abundancia del CH en nubes interestelares a través de la observación de las líneas hiperfinas del CH en 3,3 GHz. El CH es una molécula de amplia distribución en el espacio interestelar y una de las pocas especies que han sido observadas tanto con técnicas de radio como ópticas. Desde el punto de vista tecnológico se ha desarrollado un cabezal de receptor que permitirá la realización de observaciones polarimétricas en la frecuencia de 3,3 GHz, con una temperatura del sistema de 60 K y un ancho de banda de 140 MHz, y que será instalado en el foco primario de la antena parabólica del IAR. El cabezal del receptor es capaz de detectar señales polarizadas, separando las componentes de polarización circular derecha e izquierda. Para tal fin el cabezal consta de dos ramas receptoras que amplificarán la señal y la trasladarán a una frecuencia más baja (frecuencia intermedia), permitiendo de esa forma un mejor transporte de la señal a la sala de control para su posterior procesamiento. El receptor además de tener características polarimétricas, podrá ser usado en el continuo y en la línea, utilizando las ventajas observacionales y de procesamiento de señal que actualmente posee el IAR.
Higher (odd) dimensional quantum Hall effect and extended dimensional hierarchy
NASA Astrophysics Data System (ADS)
Hasebe, Kazuki
2017-07-01
We demonstrate dimensional ladder of higher dimensional quantum Hall effects by exploiting quantum Hall effects on arbitrary odd dimensional spheres. Non-relativistic and relativistic Landau models are analyzed on S 2 k - 1 in the SO (2 k - 1) monopole background. The total sub-band degeneracy of the odd dimensional lowest Landau level is shown to be equal to the winding number from the base-manifold S 2 k - 1 to the one-dimension higher SO (2 k) gauge group. Based on the chiral Hopf maps, we clarify the underlying quantum Nambu geometry for odd dimensional quantum Hall effect and the resulting quantum geometry is naturally embedded also in one-dimension higher quantum geometry. An origin of such dimensional ladder connecting even and odd dimensional quantum Hall effects is illuminated from a viewpoint of the spectral flow of Atiyah-Patodi-Singer index theorem in differential topology. We also present a BF topological field theory as an effective field theory in which membranes with different dimensions undergo non-trivial linking in odd dimensional space. Finally, an extended version of the dimensional hierarchy for higher dimensional quantum Hall liquids is proposed, and its relationship to quantum anomaly and D-brane physics is discussed.
NASA Technical Reports Server (NTRS)
Juday, Richard D. (Inventor)
1992-01-01
A two-dimensional vernier scale is disclosed utilizing a cartesian grid on one plate member with a polar grid on an overlying transparent plate member. The polar grid has multiple concentric circles at a fractional spacing of the spacing of the cartesian grid lines. By locating the center of the polar grid on a location on the cartesian grid, interpolation can be made of both the X and Y fractional relationship to the cartesian grid by noting which circles coincide with a cartesian grid line for the X and Y direction.
Three-dimensional metamaterials
Burckel, David Bruce
2012-06-12
A fabrication method is capable of creating canonical metamaterial structures arrayed in a three-dimensional geometry. The method uses a membrane suspended over a cavity with predefined pattern as a directional evaporation mask. Metallic and/or dielectric material can be evaporated at high vacuum through the patterned membrane to deposit resonator structures on the interior walls of the cavity, thereby providing a unit cell of micron-scale dimension. The method can produce volumetric metamaterial structures comprising layers of such unit cells of resonator structures.
Uncertainty and Dimensional Calibrations.
Doiron, Ted; Stoup, John
1997-01-01
The calculation of uncertainty for a measurement is an effort to set reasonable bounds for the measurement result according to standardized rules. Since every measurement produces only an estimate of the answer, the primary requisite of an uncertainty statement is to inform the reader of how sure the writer is that the answer is in a certain range. This report explains how we have implemented these rules for dimensional calibrations of nine different types of gages: gage blocks, gage wires, ring gages, gage balls, roundness standards, optical flats indexing tables, angle blocks, and sieves.
Uncertainty and Dimensional Calibrations
Doiron, Ted; Stoup, John
1997-01-01
The calculation of uncertainty for a measurement is an effort to set reasonable bounds for the measurement result according to standardized rules. Since every measurement produces only an estimate of the answer, the primary requisite of an uncertainty statement is to inform the reader of how sure the writer is that the answer is in a certain range. This report explains how we have implemented these rules for dimensional calibrations of nine different types of gages: gage blocks, gage wires, ring gages, gage balls, roundness standards, optical flats indexing tables, angle blocks, and sieves. PMID:27805114
Dimensionality Reduction Particle Swarm Algorithm for High Dimensional Clustering
Cui, Xiaohui; ST Charles, Jesse Lee; Potok, Thomas E; Beaver, Justin M
2008-01-01
The Particle Swarm Optimization (PSO) clustering algorithm can generate more compact clustering results than the traditional K-means clustering algorithm. However, when clustering high dimensional datasets, the PSO clustering algorithm is notoriously slow because its computation cost increases exponentially with the size of the dataset dimension. Dimensionality reduction techniques offer solutions that both significantly improve the computation time, and yield reasonably accurate clustering results in high dimensional data analysis. In this paper, we introduce research that combines different dimensionality reduction techniques with the PSO clustering algorithm in order to reduce the complexity of high dimensional datasets and speed up the PSO clustering process. We report significant improvements in total runtime. Moreover, the clustering accuracy of the dimensionality reduction PSO clustering algorithm is comparable to the one that uses full dimension space.
Dimensionality reduction for registration of high-dimensional data sets.
Xu, Min; Chen, Hao; Varshney, Pramod K
2013-08-01
Registration of two high-dimensional data sets often involves dimensionality reduction to yield a single-band image from each data set followed by pairwise image registration. We develop a new application-specific algorithm for dimensionality reduction of high-dimensional data sets such that the weighted harmonic mean of Cramér-Rao lower bounds for the estimation of the transformation parameters for registration is minimized. The performance of the proposed dimensionality reduction algorithm is evaluated using three remotes sensing data sets. The experimental results using mutual information-based pairwise registration technique demonstrate that our proposed dimensionality reduction algorithm combines the original data sets to obtain the image pair with more texture, resulting in improved image registration.
Dimensional analysis revisited.
Günther, Bruno; Morgado, Enrique
2003-01-01
The applicability of dimensional analysis (DA) is discussed in relation to the metabolic scaling laws. The evolution of different theories of biological similarity has shown that the calculated reduced exponents (b) of Huxley's allometric equation are closely correlated with the numerical values obtained from the statistical analysis of empirical data. Body mass and body weight are not equivalent as biological reference systems, since in accordance to Newton's second law, the former has a dimension of a mass, while the latter should be dimensionally considered as a force (W = MLT-2). This distinction affects the coefficients of the mass exponent (alpha). This difference is of paramount importance in microgravity conditions (spaceflight) and of buoyancy during the fetal life in mammals. Furthermore, the coefficients (beta) of the length dimension, and (gamma) of the time dimension do not vary when mass or weight are utilized as reference systems. Consequently, the "specific metabolic time," that results from the ratio of basal oxygen consumption and body mass or body weight yields the "biological meaning" of the time dimension, which is of fractal nature.
Dimensional crossover in semiconductor nanostructures
NASA Astrophysics Data System (ADS)
McDonald, Matthew P.; Chatterjee, Rusha; Si, Jixin; Jankó, Boldizsár; Kuno, Masaru
2016-08-01
Recent advances in semiconductor nanostructure syntheses provide unprecedented control over electronic quantum confinement and have led to extensive investigations of their size- and shape-dependent optical/electrical properties. Notably, spectroscopic measurements show that optical bandgaps of one-dimensional CdSe nanowires are substantially (approximately 100 meV) lower than their zero-dimensional counterparts for equivalent diameters spanning 5-10 nm. But what, exactly, dictates the dimensional crossover of a semiconductor's electronic structure? Here we probe the one-dimensional to zero-dimensional transition of CdSe using single nanowire/nanorod absorption spectroscopy. We find that carrier electrostatic interactions play a fundamental role in establishing dimensional crossover. Moreover, the critical length at which this transition occurs is governed by the aspect ratio-dependent interplay between carrier confinement and dielectric contrast/confinement energies.
Dimensional crossover in semiconductor nanostructures
McDonald, Matthew P.; Chatterjee, Rusha; Si, Jixin; Jankó, Boldizsár; Kuno, Masaru
2016-01-01
Recent advances in semiconductor nanostructure syntheses provide unprecedented control over electronic quantum confinement and have led to extensive investigations of their size- and shape-dependent optical/electrical properties. Notably, spectroscopic measurements show that optical bandgaps of one-dimensional CdSe nanowires are substantially (approximately 100 meV) lower than their zero-dimensional counterparts for equivalent diameters spanning 5–10 nm. But what, exactly, dictates the dimensional crossover of a semiconductor's electronic structure? Here we probe the one-dimensional to zero-dimensional transition of CdSe using single nanowire/nanorod absorption spectroscopy. We find that carrier electrostatic interactions play a fundamental role in establishing dimensional crossover. Moreover, the critical length at which this transition occurs is governed by the aspect ratio-dependent interplay between carrier confinement and dielectric contrast/confinement energies. PMID:27577091
NASA Technical Reports Server (NTRS)
2007-01-01
Nevado del Huila Volcano in Colombia is actually a volcanic chain running north to south, capped by a glacier. With peaks ranging in height from 2,600 to 5,780 meters (8,530 to 18,960 feet), Nevado del Huila is a stratovolcano composed of alternating layers of hardened lava, solidified ash, and volcanic rocks. Its first recorded eruption occurred in the mid-sixteenth century. The long-dormant volcano erupted again in mid-April 2007. A few months before the eruption, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of Nevado del Huila, on February 23, 2007. In this image, the bright white area just east of the central summit is ice. Immediately west of the summit are bare rocks, appearing as blue-gray. West of those rocks, white reappears, but this patch of white results from clouds hovering in the nearby valley. In the east, the colors turn to brown (indicating bare rock) and bright green (indicating vegetation). ASTER photographed Nevado del Huila near the end of a long phase of quietude. On April 17, 2007, local authorities recorded seismic activity associated with rock fracturing on the volcano's central summit, according to the ReliefWeb Website. Activity intensified the following day with an eruption and mudflows, forcing thousands of nearby residents to evacuate. As the Associated Press reported, the eruption caused avalanches and floods that wiped away both houses and bridges. It marked the volcano's first recorded eruption since the Spanish colonized the area five centuries earlier. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.
Three dimensional interactive display
NASA Technical Reports Server (NTRS)
Vranish, John M. (Inventor)
2005-01-01
A three-dimensional (3-D) interactive display and method of forming the same, includes a transparent capaciflector (TC) camera formed on a transparent shield layer on the screen surface. A first dielectric layer is formed on the shield layer. A first wire layer is formed on the first dielectric layer. A second dielectric layer is formed on the first wire layer. A second wire layer is formed on the second dielectric layer. Wires on the first wire layer and second wire layer are grouped into groups of parallel wires with a turnaround at one end of each group and a sensor pad at the opposite end. An operational amplifier is connected to each of the sensor pads and the shield pad biases the pads and receives a signal from connected sensor pads in response to intrusion of a probe. The signal is proportional to probe location with respect to the monitor screen.
Two-Dimensional Chirality in Three-Dimensional Chemistry.
ERIC Educational Resources Information Center
Wintner, Claude E.
1983-01-01
The concept of two-dimensional chirality is used to enhance students' understanding of three-dimensional stereochemistry. This chirality is used as a key to teaching/understanding such concepts as enaniotropism, diastereotopism, pseudoasymmetry, retention/inversion of configuration, and stereochemical results of addition to double bonds. (JN)
Dimensional stabilization of southern pines
E.T. Choong; H.M. Barnes
1969-01-01
The effectiveness of five dimensional stabilizing agents and three impregnation methods on southern pine was determined. Four southern pine species were studies in order to determine the effect of wood factors. The best dimensional stability was obtained when the wood was preswollen and the chemical was impregnated by a diffusion process. In general, polyethylene...
Lenz's law and dimensional analysis
NASA Astrophysics Data System (ADS)
Pelesko, John A.; Cesky, Michael; Huertas, Sharon
2005-01-01
We show that the time it takes a magnet to fall through a nonmagnetic metallic tube may be found via dimensional analysis. The simple analysis makes this classic demonstration of Lenz's law accessible qualitatively and quantitatively to students with little knowledge of electromagnetism and only elementary knowledge of calculus. The analysis provides a new example of the power and limitations of dimensional analysis.
Three-dimensional echocardiographic technology.
Salgo, Ivan S
2007-05-01
This article addresses the current state of the art of technology in three-dimensional echocardiography as it applies to transducer design, beam forming, display, and quantification. Because three-dimensional echocardiography encompasses many technical and clinical areas, this article reviews its strengths and limitations and concludes with an analysis of what to use when.
Three-Dimensional Photo Structures
ERIC Educational Resources Information Center
Vieth, Ken
2006-01-01
People influence lives in many ways. Through the author's desire to encourage high school students to reflect on the influential people in their lives, he developed this three-dimensional project in which they create a celebratory three-dimensional structure that shares their impressions of themselves and those who have influenced them. This…
Three dimensional Dirac semimetals
NASA Astrophysics Data System (ADS)
Zaheer, Saad
We extend the physics of graphene to three dimensional systems by showing that Dirac points can exist on the Fermi surface of realistic materials in three dimensions. Many of the exotic electronic properties of graphene can be ascribed to the pseudorelativistic behavior of its charge carriers due to two dimensional Dirac points on the Fermi surface. We show that certain nonsymmorphic spacegroups exhibit Dirac points among the irreducible representations of the appropriate little group at high symmetry points on the surface of the Brillouin zone. We provide a list of all Brillouin zone momenta in the 230 spacegroups that can host Dirac points. We describe microscopic considerations necessary to design materials in one of the candidate spacegroups such that the Dirac point appears at the Fermi energy without any additional non-Dirac-like Fermi pockets. We use density functional theory based methods to propose six new Dirac semimetals: BiO 2 and SbO2 in the beta-cristobalite lattice (spacegroup 227), and BiCaSiO4, BiMgSiO4, BiAlInO 4, and BiZnSiO4 in the distorted spinels lattice (spacegroup 74). Additionally we derive effective Dirac Hamiltonians given group representative operators as well as tight binding models incorporating spin-orbit coupling. Finally we study the Fermi surface of zincblende (spacegroup 216) HgTe which is effectively point-like at Gamma in the Brillouin zone and exhibits accidental degeneracies along a threefold rotation axis. Whereas compressive strain gaps the band structure into a topological insulator, tensile strain shifts the accidental degeneracies away from Gamma and enlarges the Fermi surface. States on the Fermi surface exhibit nontrivial spin texture marked by winding of spins around the threefold rotation axis and by spin vortices indicating a change in the winding number. This is confirmed by microscopic calculations performed in tensile strained HgTe and Hg0.5Zn 0.5 Te as well as k.p theory. We conclude with a summary of recent
Two-dimensional NMR spectrometry
Farrar, T.C.
1987-06-01
This article is the second in a two-part series. In part one (ANALYTICAL CHEMISTRY, May 15) the authors discussed one-dimensional nuclear magnetic resonance (NMR) spectra and some relatively advanced nuclear spin gymnastics experiments that provide a capability for selective sensitivity enhancements. In this article and overview and some applications of two-dimensional NMR experiments are presented. These powerful experiments are important complements to the one-dimensional experiments. As in the more sophisticated one-dimensional experiments, the two-dimensional experiments involve three distinct time periods: a preparation period, t/sub 0/; an evolution period, t/sub 1/; and a detection period, t/sub 2/.
Higher dimensional loop quantum cosmology
NASA Astrophysics Data System (ADS)
Zhang, Xiangdong
2016-07-01
Loop quantum cosmology (LQC) is the symmetric sector of loop quantum gravity. In this paper, we generalize the structure of loop quantum cosmology to the theories with arbitrary spacetime dimensions. The isotropic and homogeneous cosmological model in n+1 dimensions is quantized by the loop quantization method. Interestingly, we find that the underlying quantum theories are divided into two qualitatively different sectors according to spacetime dimensions. The effective Hamiltonian and modified dynamical equations of n+1 dimensional LQC are obtained. Moreover, our results indicate that the classical big bang singularity is resolved in arbitrary spacetime dimensions by a quantum bounce. We also briefly discuss the similarities and differences between the n+1 dimensional model and the 3+1 dimensional one. Our model serves as a first example of higher dimensional loop quantum cosmology and offers the possibility to investigate quantum gravity effects in higher dimensional cosmology.
USDA-ARS?s Scientific Manuscript database
Los ácaros constituyen un grupo abundante y diverso que ocupa diferentes hábitats en árboles frutales y la estructura y disposición del follaje y ramas del mango, contribuyen significativamente a que se presente gran diversidad de ácaros benéficos y dañinos asociados a esta especie frutal. En Colomb...
Cloaking two-dimensional fermions
Lin, De-Hone
2011-09-15
A cloaking theory for a two-dimensional spin-(1/2) fermion is proposed. It is shown that the spinor of the two-dimensional fermion can be cloaked perfectly through controlling the fermion's energy and mass in a specific manner moving in an effective vector potential inside a cloaking shell. Different from the cloaking of three-dimensional fermions, the scaling function that determines the invisible region is uniquely determined by a nonlinear equation. It is also shown that the efficiency of the cloaking shell is unaltered under the Aharonov-Bohm effect.
Three-dimensional marginal separation
NASA Technical Reports Server (NTRS)
Duck, Peter W.
1988-01-01
The three dimensional marginal separation of a boundary layer along a line of symmetry is considered. The key equation governing the displacement function is derived, and found to be a nonlinear integral equation in two space variables. This is solved iteratively using a pseudo-spectral approach, based partly in double Fourier space, and partly in physical space. Qualitatively, the results are similar to previously reported two dimensional results (which are also computed to test the accuracy of the numerical scheme); however quantitatively the three dimensional results are much different.
Dimensional interpolation for nonlinear filters
NASA Astrophysics Data System (ADS)
Daum, Fred
2005-09-01
Dimensional interpolation has been used successfully by physicists and chemists to solve the Schroedinger equation for atoms and complex molecules. The same basic idea can be used to solve the Fokker-Planck equation for nonlinear filters. In particular, it is well known (by physicists) that two Schroedinger equations are equivalent to two Fokker-Planck equations. Moreover, we can avoid the Schroedinger equation altogether and use dimensional interpolation directly on the Fokker-Planck equation. Dimensional interpolation sounds like a crazy idea, but it works. We will attempt to make this paper accessible to normal engineers who do not have quantum mechanics for breakfast.
Physical model of dimensional regularization
NASA Astrophysics Data System (ADS)
Schonfeld, Jonathan F.
2016-12-01
We explicitly construct fractals of dimension 4{-}ɛ on which dimensional regularization approximates scalar-field-only quantum-field theory amplitudes. The construction does not require fractals to be Lorentz-invariant in any sense, and we argue that there probably is no Lorentz-invariant fractal of dimension greater than 2. We derive dimensional regularization's power-law screening first for fractals obtained by removing voids from 3-dimensional Euclidean space. The derivation applies techniques from elementary dielectric theory. Surprisingly, fractal geometry by itself does not guarantee the appropriate power-law behavior; boundary conditions at fractal voids also play an important role. We then extend the derivation to 4-dimensional Minkowski space. We comment on generalization to non-scalar fields, and speculate about implications for quantum gravity.
Mixed-dimensional Bose polaron
NASA Astrophysics Data System (ADS)
Loft, Niels Jakob Søe; Wu, Zhigang; Bruun, G. M.
2017-09-01
A new generation of cold atom experiments trapping atomic mixtures in species-selective optical potentials opens up the intriguing possibility to create systems in which different atoms live in different spatial dimensions. Inspired by this, we investigate a mixed-dimensional Bose polaron consisting of an impurity particle moving in a two-dimensional (2D) layer immersed in a 3D Bose-Einstein condensate (BEC), using a theory that includes the mixed-dimensional vacuum scattering between the impurity and the bosons exactly. We show that similarly to the pure 3D case, this system exhibits a well-defined polaron state for attractive boson-impurity interaction that evolves smoothly into a mixed-dimensional dimer for strong attraction, as well as a well-defined polaron state for weak repulsive interaction, which becomes overdamped for strong interaction. We furthermore find that the properties of the polaron depend only weakly on the gas parameter of the BEC as long as the Bogoliubov theory remains a valid description for the BEC. This indicates that higher-order correlations between the impurity and the bosons are suppressed by the mixed-dimensional geometry in comparison to a pure 3D system, which led us to speculate that the mixed-dimensional polaron has universal properties in the unitarity limit of the impurity-boson interaction.
Three Dimensional Modeling of Breaking
2005-09-30
R.A. Dalrymple, A.J.C. Crespo, and D. Cerquiero, "Uso de la Tecnica SPH para el Estudio de la Interaccion entre Olas y Estructuras," Ingenieria del...published] Rogers, B.D., R.A. Dalrymple, M. Gesteira, and O. Knio, ``Smoothed Particle Hydrodynamics for Naval Hydrodynamics,” Proc. Int. Workshop on
Three dimensional canonical singularity and five dimensional N = 1 SCFT
NASA Astrophysics Data System (ADS)
Xie, Dan; Yau, Shing-Tung
2017-06-01
We conjecture that every three dimensional canonical singularity defines a five dimensional N = 1 SCFT. Flavor symmetry can be found from singularity structure: non-abelian flavor symmetry is read from the singularity type over one dimensional singular locus. The dimension of Coulomb branch is given by the number of compact crepant divisors from a crepant resolution of singularity. The detailed structure of Coulomb branch is described as follows: a) a chamber of Coulomb branch is described by a crepant resolution, and this chamber is given by its Nef cone and the prepotential is computed from triple intersection numbers; b) Crepant resolution is not unique and different resolutions are related by flops; Nef cones from crepant resolutions form a fan which is claimed to be the full Coulomb branch.
Case Study: del Amo Bioventing
The attached presentation discusses the fundamentals of bioventing in the vadose zone. The basics of bioventing are presented. The experience to date with the del Amo Superfund Site is presented as a case study.
Case Study: del Amo Bioventing
The attached presentation discusses the fundamentals of bioventing in the vadose zone. The basics of bioventing are presented. The experience to date with the del Amo Superfund Site is presented as a case study.
Observational effects from dimensional compactification
NASA Astrophysics Data System (ADS)
Kontou, Eleni-Alexandra; Blanco-Pillado, Jose-Juan; Hertzberg, Mark; Masoumi, Ali
2017-01-01
Many of the extensions of the Standard Model involve theories that live on a higher dimensional spacetime. On the other hand, all our observational evidence points to a 4-dimensional description of the universe at low energies so one way to accommodate these higher dimensional theories is to allow for a compactifation mechanism. In this work we explore the possibility that we can obtain any observational signature that points towards the existence of this type of process in our past. Certain so-called anomalies in the CMB data might be giving us a hint that the amount of inflation was just the minimal required to solve the cosmological problems but not longer. In such case, we might hope to see the effects of a previous state of the universe in the power spectrum of perturbations. We assume the spacetime is divided in two parts, the 3+1 dimensional manifold and an internal space of n flat compact dimensions. Before the compactification, the extra dimensions can either be expanding or contracting and we compare the observable consequences obtained within these different higher dimensional cosmological scenarios.
The Effects of Dimensionality in Computer Graphics.
ERIC Educational Resources Information Center
Addo, Theophilus B. A.
1994-01-01
Investigates how the dimensionality of computer-generated graphs affects users' abilities to extract information from the graphs. Finds two-dimensional graphs more reliable in communicating information quickly and accurately than corresponding three-dimensional graphs. Notes that a commonly used, but technically incorrect, three-dimensional graph…
Conservacion de truchas del Pacifico
Brooke E. Penaluna
2016-01-01
La historia de las truchas del PacÃfico, pertenecientes al gÃ©nero Oncorhynchus, es una historia muy interesante que se basa en la persistencia y diversificaciÃ³n de sus especies debido, en gran parte, al dinamismo propio que existe en su medio ambiente. Desde el oeste de NorteamÃ©rica, extendiÃ©ndose hasta el este de Asia, las truchas del PacÃfico han experimentado la...
Three-dimensional perspective visualization
NASA Technical Reports Server (NTRS)
Hussey, Kevin
1991-01-01
It was demonstrated that image processing computer graphic techniques can provide an effective means of physiographic analysis of remotely sensed regions through the use of three-dimensional perspective rendering. THe methods used to simulate and animate three-dimensional surfaces from two-dimensional imagery and digital elevation models are explained. A brief historic look at JPL's efforts in this field and several examples of animations, illustrating the evolution of these techniques from 1985, are shown. JPL's current research in this area is discussed along with examples of technology transfer and potential commercial application. The software is part of the VICAR (Video Image Communication and Retrieval) image processing system which was developed at the Multimission Image Processing Laboratory of JPL.
Dimensionality of the human electroencephalogram
Mayer-Kress, G.; Layne, S.P.
1986-01-01
The goal was to evaluate anesthetic depth in patients by dimensional analysis. Although it was difficult to obtain clean EEG records from the operating room due to noise of electrocautery and movement of the patient's head by operating room personnel. The results are presented on one case of our calculations, followed by a discussion of problems associated with dimensional analysis of the EEG. We consider only two states: aware but quiet, and medium anesthesia. The EEG data we use comes from Hanley and Walts. It was selected because anesthesia was induced by a single agent, and because of its uninterrupted length and lack of artifacts. 26 refs., 27 figs., 1 tab.
Low-Dimensional Semiconductor Structures
NASA Astrophysics Data System (ADS)
Barnham, Keith; Vvedensky, Dimitri
2001-08-01
Low-Dimensional Semiconductor Structures offers a seamless, atoms-to-devices introduction to the latest quantum heterostructures. It covers their fabrication; electronic, optical, and transport properties; role in exploring new physical phenomena; and utilization in devices. The authors describe the epitaxial growth of semiconductors and the physical behavior of electrons and phonons in low-dimensional structures. They then go on to discuss nonlinear optics in quantum heterostructures. The final chapters deal with semiconductor lasers, mesoscopic devices, and high-speed heterostructure devices. The book contains many exercises and comprehensive references.
NASA Technical Reports Server (NTRS)
Jackman, Charles H.; Douglass, Anne R.; Stolarski, Richard S.; Guthrie, Paul D.; Thompson, A. M.
1990-01-01
A two dimensional (altitude and latitude) model of the atmosphere is used to investigate problems relating to the variability of the dynamics and temperature of the atmosphere on the ozone distribution, solar cycle variations of atmospheric constituents, the sensitivity of model results to tropospheric trace gas sources, and assessment computations of changes in ozone related to manmade influences. In a comparison between two dimensional model results in which the odd nitrogen family was transported together and model results in which the odd nitrogen species was transported separately, it was found that the family approximations are adequate for perturbation scenario calculations.
Conocimientos y autoeficacia asociados a la prevención del VIH y SIDA en mujeres chilenas
Villegas Rodríguez, Natalia; Ferrer Lagunas, Lilian Marcela; Cianelli Acosta, Rosina; Miner, Sarah; Lara Campos, Loreto; Peragallo, Nilda
2014-01-01
Resumen Objetivo Evaluar la relación existente entre conocimientos y autoeficacia asociados al VIH/SIDA en mujeres chilenas en desventaja social. Metodología Estudio correlacional, que utiliza la medición basal del estudio “Testeando una intervención en VIH y SIDA en mujeres chilenas”, realizada entre 2006 y 2008, que tiene una muestra de 496 mujeres entre 18 y 49 años residentes en dos comunas de Santiago de Chile. Las participantes respondieron un cuestionario estructurado aplicado por entrevistadoras entrenadas. Este cuestionario incluyó preguntas sobre datos sociodemográficos, escala de conocimientos de conductas de riesgo y autoeficacia, entre otros. Resultados Edad promedio de 32.3±9.1 años, 72.2% vive con su pareja y 42.7% poseen educación media completa. La puntuación media de los conocimientos de la infección por el VIH fue de 8.9±2.5, mientras que para las tres escalas empleadas para medir autoeficacia fueron: “Normas de los pares” =9.8±3.6, “Intención de reducir conductas de riesgo” =12.2±3.6 y “Self Efficacy Form”=20.2±4.7. Los conocimientos tuvieron una correlación positiva débil con la “intención de reducir conductas de riesgo” (r=0.19; p<0.0001) y con la escala “Self Efficacy Form” (r=0.34; p<0.0001), pero no se relacionaron con las “normas de los pares en cuanto a relaciones sexuales seguras” (r=0.13; p=0.78). Conclusión Existe una débil correlación positiva entre el nivel de conocimientos sobre el VIH/SIDA y la autoeficacia en mujeres chilenas en desventaja social. PMID:25284914
Dimensional Reduction and Hadronic Processes
Signer, Adrian; Stoeckinger, Dominik
2008-11-23
We consider the application of regularization by dimensional reduction to NLO corrections of hadronic processes. The general collinear singularity structure is discussed, the origin of the regularization-scheme dependence is identified and transition rules to other regularization schemes are derived.
Dimensionality and the sample unit
Francis A. Roesch
2009-01-01
The sample unit and its implications for the Forest Service, U.S. Department of Agriculture's Forest Inventory and Analysis program are discussed in light of a generalized three-dimensional concept of continuous forest inventories. The concept views the sampled population as a spatial-temporal cube and the sample as a finite partitioning of the cube. The sample...
Dimensional mutation and spacelike singularities
Silverstein, Eva
2006-04-15
I argue that string theory compactified on a Riemann surface crosses over at small volume to a higher dimensional background of supercritical string theory. Several concrete measures of the count of degrees of freedom of the theory yield the consistent result that at finite volume, the effective dimensionality is increased by an amount of order 2h/V for a surface of genus h and volume V in string units. This arises in part from an exponentially growing density of states of winding modes supported by the fundamental group, and passes an interesting test of modular invariance. Further evidence for a plethora of examples with the spacelike singularity replaced by a higher dimensional phase arises from the fact that the sigma model on a Riemann surface can be naturally completed by many gauged linear sigma models, whose RG flows approximate time evolution in the full string backgrounds arising from this in the limit of large dimensionality. In recent examples of spacelike singularity resolution by tachyon condensation, the singularity is ultimately replaced by a phase with all modes becoming heavy and decoupling. In the present case, the opposite behavior ensues: more light degrees of freedom arise in the small radius regime. We comment on the emerging zoology of cosmological singularities that results.
Three dimensional colorimetric assay assemblies
Charych, D.; Reichart, A.
2000-06-27
A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.
Three dimensional colorimetric assay assemblies
Charych, Deborah; Reichart, Anke
2000-01-01
A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.
The Dimensionality of Grammatical Variation
ERIC Educational Resources Information Center
Sankoff, David; Cedergren, Henrietta J.
1976-01-01
Computer-based multidimensional scaling techniques are used to determine the dimensionality of grammatical variation in three large sets of data: Ross' (1973) Noun Phrase and fake Noun Phrase data; Sankoff's (1974) complementizer "que"-deletion (Montreal French) data; and Cedergren's (1973) syllable-final S-reduction (Panamanian Spanish) data. (DB)
Three-Dimensional Lissajous Figures.
ERIC Educational Resources Information Center
D'Mura, John M.
1989-01-01
Described is a mechanically driven device for generating three-dimensional harmonic space figures with different frequencies and phase angles on the X, Y, and Z axes. Discussed are apparatus, viewing stereo pairs, equations of motion, and using space figures in classroom. (YP)
Three-dimensional stellarator codes
Garabedian, P. R.
2002-01-01
Three-dimensional computer codes have been used to develop quasisymmetric stellarators with modular coils that are promising candidates for a magnetic fusion reactor. The mathematics of plasma confinement raises serious questions about the numerical calculations. Convergence studies have been performed to assess the best configurations. Comparisons with recent data from large stellarator experiments serve to validate the theory. PMID:12140367
Compressione gravitazionale in una dimensione
NASA Astrophysics Data System (ADS)
Ruffini, Remo; Sigismondi, Costantino
2017-05-01
The mass to produce mini black holes should surpass the repulsive force due to Pauli exclusion principle. The compression energy on the one dimensional case is calculated. The extra-mass in the mass energy balance rises as the added mass approaches the Schwarzschild radius.
Creating Three-Dimensional Scenes
ERIC Educational Resources Information Center
Krumpe, Norm
2005-01-01
Persistence of Vision Raytracer (POV-Ray), a free computer program for creating photo-realistic, three-dimensional scenes and a link for Mathematica users interested in generating POV-Ray files from within Mathematica, is discussed. POV-Ray has great potential in secondary mathematics classrooms and helps in strengthening students' visualization…
Three-Dimensional Lissajous Figures.
ERIC Educational Resources Information Center
D'Mura, John M.
1989-01-01
Described is a mechanically driven device for generating three-dimensional harmonic space figures with different frequencies and phase angles on the X, Y, and Z axes. Discussed are apparatus, viewing stereo pairs, equations of motion, and using space figures in classroom. (YP)
Creating Three-Dimensional Scenes
ERIC Educational Resources Information Center
Krumpe, Norm
2005-01-01
Persistence of Vision Raytracer (POV-Ray), a free computer program for creating photo-realistic, three-dimensional scenes and a link for Mathematica users interested in generating POV-Ray files from within Mathematica, is discussed. POV-Ray has great potential in secondary mathematics classrooms and helps in strengthening students' visualization…
Multi Dimensional Phase Only Filter
Gudmundsson, K; Awwal, A
2004-07-13
Today's sensor networks provide a wide variety of application domain for high-speed pattern classification systems. Such high-speed systems can be achieved by the use of optical implementation of specialized POF correlator. In this research we discuss the modeling and simulation of the phase only filter (POF) in the task of pattern classification of multi-dimensional data.
El libro del Relogio del Palacio de las Horas
NASA Astrophysics Data System (ADS)
Morales, J. D.
2009-08-01
This paper resume the investigation entitled ``El libro del Relogio del Palacio de las Horas''. That consist in an edition of the original text of the book of the Clock of the Palace of the Hours from the Books of the knowledge of Astronomy of Alfonso X (Manuscript 156, Complutense University). And a description of the astronomical functionality of the Clock of the Palace of the Hours. It includes a geometric description of the positional astronomy on which the operation of the Palace is based.
4-dimensional spacetimes from 2-dimensional conformal null data
NASA Astrophysics Data System (ADS)
Goswami, Rituparno; Ellis, George F. R.
2017-03-01
In this paper we investigate whether the holographic principle proposed in string theory has a classical counterpart in general relativity theory. We show that there is a partial correspondence: at least in the case of vacuum Petrov type D spacetimes that admit a non-trivial Killing tensor, which encompass all the astrophysical black hole spacetimes, there exists a one-to-one correspondence between gravity in bulk and a 2-dimensional classical conformal scalar field on a null boundary.
Three-dimensional force-free looplike magnetohydrodynamic equilibria
NASA Technical Reports Server (NTRS)
Finn, John M.; Guzdar, Parvez N.; Usikov, Daniel
1994-01-01
Computations of three-dimensional force-free magnetohydrodynamic (MHD) equilibria, del x B = lambdaB with lambda = lambda(sub 0), a constant are presented. These equilibria are determined by boundary conditions on a surface corresponding to the solar photosphere. The specific boundary conditions used correspond to looplike magnetic fields in the corona. It is found that as lambda(sub 0) is increased, the loops of flux become kinked, and for sufficiently large lambda(sub 0), develop knots. The relationship between the kinking and knotting properties of these equilibria and the presence of a kink instability and related loss of equilibrium is explored. Clearly, magnetic reconnection must be involved for an unknotted loop equilibrium to become knotted, and speculations are made about the creation of a closed hyperbolic field line (X-line) about which this reconnection creating knotted field lines is centered.
Three-dimensional force-free looplike magnetohydrodynamic equilibria
NASA Technical Reports Server (NTRS)
Finn, John M.; Guzdar, Parvez N.; Usikov, Daniel
1994-01-01
Computations of three-dimensional force-free magnetohydrodynamic (MHD) equilibria, del x B = lambdaB with lambda = lambda(sub 0), a constant are presented. These equilibria are determined by boundary conditions on a surface corresponding to the solar photosphere. The specific boundary conditions used correspond to looplike magnetic fields in the corona. It is found that as lambda(sub 0) is increased, the loops of flux become kinked, and for sufficiently large lambda(sub 0), develop knots. The relationship between the kinking and knotting properties of these equilibria and the presence of a kink instability and related loss of equilibrium is explored. Clearly, magnetic reconnection must be involved for an unknotted loop equilibrium to become knotted, and speculations are made about the creation of a closed hyperbolic field line (X-line) about which this reconnection creating knotted field lines is centered.
Numerical solution of three-dimensional magnetic differential equations
Reiman, A.H.; Greenside, H.S.
1987-02-01
A computer code is described that solves differential equations of the form B . del f = h for a single-valued solution f, given a toroidal three-dimensional divergence-free field B and a single-valued function h. The code uses a new algorithm that Fourier decomposes a given function in a set of flux coordinates in which the field lines are straight. The algorithm automatically adjusts the required integration lengths to compensate for proximity to low order rational surfaces. Applying this algorithm to the Cartesian coordinates defines a transformation to magnetic coordinates, in which the magnetic differential equation can be accurately solved. Our method is illustrated by calculating the Pfirsch-Schlueter currents for a stellarator.
Discriminative Dimensionality Reduction for Multi-dimensional Sequences.
Su, Bing; Ding, Xiaoqing; Wang, Hao; Wu, Ying
2017-02-07
Since the observables at particular time instants in a temporal sequence exhibit dependencies, they are not independent samples. Thus, it is not plausible to apply i.i.d. assumption-based dimensionality reduction methods to sequence data. This paper presents a novel supervised dimensionality reduction approach for sequence data, called Linear Sequence Discriminant Analysis (LSDA). It learns a linear discriminative projection of the feature vectors in sequences to a lower-dimensional subspace by maximizing the separability of the sequence classes such that the entire sequences are holistically discriminated. The sequence class separability is constructed based on the sequence statistics, and the use of different statistics produces different LSDA methods. This paper presents and compares two novel LSDA methods, namely M-LSDA and D-LSDA. M-LSDA extracts model-based statistics by exploiting the dynamical structure of the sequence classes, and D-LSDA extracts the distance-based statistics by computing the pairwise similarity of samples from the same sequence class. Extensive experiments on several different tasks have demonstrated the effectiveness and the general applicability of the proposed methods.
Torres del Paine National Park
2017-09-27
Grinding glaciers and granite peaks mingle in Chile’s Torres del Paine National Park. The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this summertime image of the park on January 21, 2013. This image shows just a portion of the park, including Grey Glacier and the mountain range of Cordillera del Paine. The rivers of glacial ice in Torres del Paine National Park grind over bedrock, turning some of that rock to dust. Many of the glaciers terminate in freshwater lakes, which are rich with glacial flour that colors them brown to turquoise. Skinny rivers connect some of the lakes to each other (image upper and lower right). Cordillera del Paine rises between some of the wide glacial valleys. The compact mountain range is a combination of soaring peaks and small glaciers, most notably the Torres del Paine (Towers of Paine), three closely spaced peaks emblematic of the mountain range and the larger park. By human standards, the mountains of Cordillera del Paine are quite old. But compared to the Rocky Mountains (70 million years old), and the Appalachians (about 480 million years), the Cordillera del Paine are very young—only about 12 million years old. A study published in 2008 described how scientists used zircon crystals to estimate the age of Cordillera del Paine. The authors concluded that the mountain range was built in three pulses, creating a granite laccolith, or dome-shaped feature, more than 2,000 meters (7,000 feet) thick. NASA Earth Observatory image created by Jesse Allen and Robert Simmon, using Advanced Land Imager data from the NASA EO-1 team. Caption by Michon Scott. Instrument: EO-1 - ALI View more info: earthobservatory.nasa.gov/IOTD/view.php?id=80266 Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA
Determinación del perfil instrumental del EBASIM
NASA Astrophysics Data System (ADS)
Nieva, M. F.; Rodriguez, M. V.; Pintado, O. I.
Se calcula el perfil instrumental para el telescopio de 2,15m del CASLEO con EBASIM. Para ello se usaron flats de cielo y el espectro solar FTS de Kurucz. El método, que se puede utilizar para otras configuraciones instrumentales, es convolucionar ambos espectros para obtener los coeficientes de corrección.
A New Approach To Teaching Dimensional Analysis.
ERIC Educational Resources Information Center
Churchill, Stuart W.
1997-01-01
Explains an approach to teaching dimensional analysis that differs slightly from the traditional approach. The difference lies in the novelty of exposition in the presentation and interpretation of dimensional analysis as a speculative process. (DDR)
Two-dimensional cubic convolution.
Reichenbach, Stephen E; Geng, Frank
2003-01-01
The paper develops two-dimensional (2D), nonseparable, piecewise cubic convolution (PCC) for image interpolation. Traditionally, PCC has been implemented based on a one-dimensional (1D) derivation with a separable generalization to two dimensions. However, typical scenes and imaging systems are not separable, so the traditional approach is suboptimal. We develop a closed-form derivation for a two-parameter, 2D PCC kernel with support [-2,2] x [-2,2] that is constrained for continuity, smoothness, symmetry, and flat-field response. Our analyses, using several image models, including Markov random fields, demonstrate that the 2D PCC yields small improvements in interpolation fidelity over the traditional, separable approach. The constraints on the derivation can be relaxed to provide greater flexibility and performance.
Two-dimensional flexible nanoelectronics.
Akinwande, Deji; Petrone, Nicholas; Hone, James
2014-12-17
2014/2015 represents the tenth anniversary of modern graphene research. Over this decade, graphene has proven to be attractive for thin-film transistors owing to its remarkable electronic, optical, mechanical and thermal properties. Even its major drawback--zero bandgap--has resulted in something positive: a resurgence of interest in two-dimensional semiconductors, such as dichalcogenides and buckled nanomaterials with sizeable bandgaps. With the discovery of hexagonal boron nitride as an ideal dielectric, the materials are now in place to advance integrated flexible nanoelectronics, which uniquely take advantage of the unmatched portfolio of properties of two-dimensional crystals, beyond the capability of conventional thin films for ubiquitous flexible systems.
Three-dimensional display technologies.
Geng, Jason
2013-01-01
The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) information. This fundamental restriction greatly limits our ability to perceive and to understand the complexity of real-world objects. Nearly 50% of the capability of the human brain is devoted to processing visual information [Human Anatomy & Physiology (Pearson, 2012)]. Flat images and 2D displays do not harness the brain's power effectively. With rapid advances in the electronics, optics, laser, and photonics fields, true 3D display technologies are making their way into the marketplace. 3D movies, 3D TV, 3D mobile devices, and 3D games have increasingly demanded true 3D display with no eyeglasses (autostereoscopic). Therefore, it would be very beneficial to readers of this journal to have a systematic review of state-of-the-art 3D display technologies.
Two-dimensional thermofield bosonization
Amaral, R.L.P.G.
2005-12-15
The main objective of this paper was to obtain an operator realization for the bosonization of fermions in 1 + 1 dimensions, at finite, non-zero temperature T. This is achieved in the framework of the real-time formalism of Thermofield Dynamics. Formally, the results parallel those of the T = 0 case. The well-known two-dimensional Fermion-Boson correspondences at zero temperature are shown to hold also at finite temperature. To emphasize the usefulness of the operator realization for handling a large class of two-dimensional quantum field-theoretic problems, we contrast this global approach with the cumbersome calculation of the fermion-current two-point function in the imaginary-time formalism and real-time formalisms. The calculations also illustrate the very different ways in which the transmutation from Fermi-Dirac to Bose-Einstein statistics is realized.
Two dimensional unstable scar statistics.
Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Kotulski, Joseph Daniel; Lee, Kelvin S. H. (ITT Industries/AES Los Angeles, CA)
2006-12-01
This report examines the localization of time harmonic high frequency modal fields in two dimensional cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This paper examines the enhancements for these unstable orbits when the opposing mirrors are both convex and concave. In the latter case the construction includes the treatment of interior foci.
Two-Dimensional Potential Flows
NASA Technical Reports Server (NTRS)
Schaefer, Manfred; Tollmien, W.
1949-01-01
Contents include the following: Characteristic differential equations - initial and boundary conditions. Integration of the second characteristic differential equations. Direct application of Meyer's characteristic hodograph table for construction of two-dimensional potential flows. Prandtl-Busemann method. Development of the pressure variation for small deflection angles. Numerical table: relation between deflection, pressure, velocity, mach number and mach angle for isentropic changes of state according to Prandtl-Meyer for air (k = 1.405). References.
Classification, Clustering and Dimensionality Reduction
2008-07-08
and scale remains unsolved. New and emerging applications, such as data mining , web searching, retrieval of multimedia data, face recognition and...algorithms, and (4) dimensionality reduction. Solution to these problems will advance the state-of-the-art in pattern recognition, data mining and machine...learning. These advances will also be useful to a number of pattern recognition and data mining applications of interest to the Navy.
NASA Technical Reports Server (NTRS)
Juday, Richard D.
1992-01-01
Modified vernier scale gives accurate two-dimensional coordinates from maps, drawings, or cathode-ray-tube displays. Movable circular overlay rests on fixed rectangular-grid overlay. Pitch of circles nine-tenths that of grid and, for greatest accuracy, radii of circles large compared with pitch of grid. Scale enables user to interpolate between finest divisions of regularly spaced rule simply by observing which mark on auxiliary vernier rule aligns with mark on primary rule.
Cosmological string solutions by dimensional reduction
Behrndt, K.; Foerste, S.
1993-12-01
We obtain cosmological four dimensional solutions of the low energy effective string theory by reducing a five dimensional black hole, and black hole-de Sitter solution of the Einstein gravity down to four dimensions. The appearance of a cosmological constant in the five dimensional Einstein-Hilbert produces a special dilaton potential in the four dimensional effective string action. Cosmological scenarios implement by our solutions are discussed.
Dimensional stability of natural fibers
NASA Astrophysics Data System (ADS)
Driscoll, Mark S.; Smith, Jennifer L.; Woods, Sean; Tiss, Kenneth J.; Larsen, L. Scott
2013-04-01
One of the main problems associated with the use of natural fibers as reinforcing agents in composites is their uptake of moisture. Many natural fibers are lignocellulosic, which causes them to swell and shrink as the amount of available moisture changes. Swelling and shrinking can cause composites to prematurely fail. This paper presents the results of a preliminary study that considers the use of two different low molecular weight monomers, hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA), polymerized by electron beam ionizing radiation, to dimensionally stabilize natural fibers. Eight different treatments consisting of varying amounts of monomer, encapsulating agent, and cross-linkers, were evaluated for their ability to dimensionally stabilize sisal fiber. Results indicate that both polymerized HEA and HEMA can reduce the swelling of sisal fiber. The effectiveness of HEA and HEMA can be further enhanced with the use of a cross-linker (SR 454). The use of hydroxylated monomers to dimensionally stabilize natural fibers may play an important role in reducing delamination and improving fiber-resin adhesion in composites.
Dimensional psychopharmacology in somatising patients.
Biondi, Massimo; Pasquini, Massimo
2015-01-01
Despite the recent DSM-5 review of somatoform disorders, which are now called somatic symptom and related disorders, the categorical definitions of these syndromes have inherent limitations because their causal mechanism or presumed aetiologies are still unknown. These limitations may affect everyday clinical practice and decision-making abilities. As a result, physicians have limited information at their disposal to treat these patients. Furthermore, the clinical presentations of somatic disorders may vary a lot. The purpose of this chapter is to illustrate a psychopathological dimensional approach to the somatising patient. This approach is constantly unconsciously applied in clinical practice using continuous variables, such as rating scales. Moreover, treatment strategies might be improved by adding a dimensional approach, simply recognising the prominent components of the presenting psychopathology of a given patient and addressing them with drugs according to their different mechanisms, targeting circuits and neurotransmitters. Some authors have proposed a shift from the nosological to functional application of psychotropic drugs, in which functional psychopharmacology will be dysfunction oriented and therefore inevitably geared towards utilising drug combinations. Here, we present a summary of the advantages of functional/dimensional psychopharmacology for the treatment of somatic symptoms and related disorders.
Dimensional stability of natural fibers
Driscoll, Mark S.
2013-04-19
One of the main problems associated with the use of natural fibers as reinforcing agents in composites is their uptake of moisture. Many natural fibers are lignocellulosic, which causes them to swell and shrink as the amount of available moisture changes. Swelling and shrinking can cause composites to prematurely fail. This paper presents the results of a preliminary study that considers the use of two different low molecular weight monomers, hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA), polymerized by electron beam ionizing radiation, to dimensionally stabilize natural fibers. Eight different treatments consisting of varying amounts of monomer, encapsulating agent, and cross-linkers, were evaluated for their ability to dimensionally stabilize sisal fiber. Results indicate that both polymerized HEA and HEMA can reduce the swelling of sisal fiber. The effectiveness of HEA and HEMA can be further enhanced with the use of a cross-linker (SR 454). The use of hydroxylated monomers to dimensionally stabilize natural fibers may play an important role in reducing delamination and improving fiber-resin adhesion in composites.
Rotational Invariant Dimensionality Reduction Algorithms.
Lai, Zhihui; Xu, Yong; Yang, Jian; Shen, Linlin; Zhang, David
2016-06-30
A common intrinsic limitation of the traditional subspace learning methods is the sensitivity to the outliers and the image variations of the object since they use the L₂ norm as the metric. In this paper, a series of methods based on the L₂,₁-norm are proposed for linear dimensionality reduction. Since the L₂,₁-norm based objective function is robust to the image variations, the proposed algorithms can perform robust image feature extraction for classification. We use different ideas to design different algorithms and obtain a unified rotational invariant (RI) dimensionality reduction framework, which extends the well-known graph embedding algorithm framework to a more generalized form. We provide the comprehensive analyses to show the essential properties of the proposed algorithm framework. This paper indicates that the optimization problems have global optimal solutions when all the orthogonal projections of the data space are computed and used. Experimental results on popular image datasets indicate that the proposed RI dimensionality reduction algorithms can obtain competitive performance compared with the previous L₂ norm based subspace learning algorithms.
Facial three-dimensional morphometry.
Ferrario, V F; Sforza, C; Poggio, C E; Serrao, G
1996-01-01
Three-dimensional facial morphometry was investigated in a sample of 40 men and 40 women, with a new noninvasive computerized method. Subjects ranged in age between 19 and 32 years, had sound dentitions, and no craniocervical disorders. For each subject, 16 cutaneous facial landmarks were automatically collected by a system consisting of two infrared camera coupled device (CCD) cameras, real time hardware for the recognition of markers, and software for the three-dimensional reconstruction of landmarks' x, y, z coordinates. From these landmarks, 15 linear and 10 angular measurements, and four linear distance ratios were computed and averaged for sex. For all angular values, both samples showed a narrow variability and no significant gender differences were demonstrated. Conversely, all the linear measurements were significantly higher in men than in women. The highest intersample variability was observed for the measurements of facial height (prevalent vertical dimension), and the lowest for the measurements of facial depth (prevalent horizontal dimension). The proportions of upper and lower face height relative to the anterior face height showed a significant sex difference. Mean values were in good agreement with literature data collected with traditional methods. The described method allowed the direct and noninvasive calculation of three-dimensional linear and angular measurements that would be usefully applied in clinics as a supplement to the classic x-ray cephalometric analyses.
Teleportation of a 3-dimensional GHZ State
NASA Astrophysics Data System (ADS)
Cao, Hai-Jing; Wang, Huai-Sheng; Li, Peng-Fei; Song, He-Shan
2012-05-01
The process of teleportation of a completely unknown 3-dimensional GHZ state is considered. Three maximally entangled 3-dimensional Bell states function as quantum channel in the scheme. This teleportation scheme can be directly generalized to teleport an unknown d-dimensional GHZ state.
Assessment of Dimensionality in Social Science Subtest
ERIC Educational Resources Information Center
Ozbek Bastug, Ozlem Yesim
2012-01-01
Most of the literature on dimensionality focused on either comparison of parametric and nonparametric dimensionality detection procedures or showing the effectiveness of one type of procedure. There is no known study to shown how to do combined parametric and nonparametric dimensionality analysis on real data. The current study is aimed to fill…
Orthogonality preserving infinite dimensional quadratic stochastic operators
Akın, Hasan; Mukhamedov, Farrukh
2015-09-18
In the present paper, we consider a notion of orthogonal preserving nonlinear operators. We introduce π-Volterra quadratic operators finite and infinite dimensional settings. It is proved that any orthogonal preserving quadratic operator on finite dimensional simplex is π-Volterra quadratic operator. In infinite dimensional setting, we describe all π-Volterra operators in terms orthogonal preserving operators.
On timelike supersymmetric solutions of gauged minimal 5-dimensional supergravity
NASA Astrophysics Data System (ADS)
Chimento, Samuele; Ortín, Tomás
2017-04-01
We analyze the timelike supersymmetric solutions of minimal gauged 5-dimensional supergravity for the case in which the Kähler base manifold admits a holomorphic isometry and depends on two real functions satisfying a simple second-order differential equation. Using this general form of the base space, the equations satisfied by the building blocks of the solutions become of, at most, fourth degree and can be solved by simple polynomic ansatzs. In this way we construct two 3-parameter families of solutions that contain almost all the timelike supersymmetric solutions of this theory with one angular momentum known so far and a few more: the (singular) supersymmetric Reissner-Nordström-AdS solutions, the three exact supersymmetric solutions describing the three near-horizon geometries found by Gutowski and Reall, three 1-parameter asymptotically-AdS5 black-hole solutions with those three near-horizon geometries (Gutowski and Reall's black hole being one of them), three generalizations of the Gödel universe and a few potentially homogenous solutions. A key rôle in finding these solutions is played by our ability to write AdS5's Kähler base space ( {\\overline{CP}}^2 or SU(1, 2)/U(2)) is three different, yet simple, forms associated to three different isometries. Furthermore, our ansatz for the Kähler metric also allows us to study the dimensional compactification of the theory and its solutions in a systematic way.
Extra-dimensional models on the lattice
Knechtli, Francesco; Rinaldi, Enrico
2016-08-05
In this paper we summarize the ongoing effort to study extra-dimensional gauge theories with lattice simulations. In these models the Higgs field is identified with extra-dimensional components of the gauge field. The Higgs potential is generated by quantum corrections and is protected from divergences by the higher dimensional gauge symmetry. Dimensional reduction to four dimensions can occur through compactification or localization. Gauge-Higgs unification models are often studied using perturbation theory. Numerical lattice simulations are used to go beyond these perturbative expectations and to include nonperturbative effects. We describe the known perturbative predictions and their fate in the strongly-coupled regime for various extra-dimensional models.
Extra-dimensional models on the lattice
Knechtli, Francesco; Rinaldi, Enrico
2016-08-05
In this paper we summarize the ongoing effort to study extra-dimensional gauge theories with lattice simulations. In these models the Higgs field is identified with extra-dimensional components of the gauge field. The Higgs potential is generated by quantum corrections and is protected from divergences by the higher dimensional gauge symmetry. Dimensional reduction to four dimensions can occur through compactification or localization. Gauge-Higgs unification models are often studied using perturbation theory. Numerical lattice simulations are used to go beyond these perturbative expectations and to include nonperturbative effects. We describe the known perturbative predictions and their fate in the strongly-coupled regime for various extra-dimensional models.
Three dimensional identification card and applications
NASA Astrophysics Data System (ADS)
Zhou, Changhe; Wang, Shaoqing; Li, Chao; Li, Hao; Liu, Zhao
2016-10-01
Three dimensional Identification Card, with its three-dimensional personal image displayed and stored for personal identification, is supposed be the advanced version of the present two-dimensional identification card in the future [1]. Three dimensional Identification Card means that there are three-dimensional optical techniques are used, the personal image on ID card is displayed to be three-dimensional, so we can see three dimensional personal face. The ID card also stores the three-dimensional face information in its inside electronics chip, which might be recorded by using two-channel cameras, and it can be displayed in computer as three-dimensional images for personal identification. Three-dimensional ID card might be one interesting direction to update the present two-dimensional card in the future. Three-dimension ID card might be widely used in airport custom, entrance of hotel, school, university, as passport for on-line banking, registration of on-line game, etc...
Statistical Downscaling in Multi-dimensional Wave Climate Forecast
NASA Astrophysics Data System (ADS)
Camus, P.; Méndez, F. J.; Medina, R.; Losada, I. J.; Cofiño, A. S.; Gutiérrez, J. M.
2009-04-01
Wave climate at a particular site is defined by the statistical distribution of sea state parameters, such as significant wave height, mean wave period, mean wave direction, wind velocity, wind direction and storm surge. Nowadays, long-term time series of these parameters are available from reanalysis databases obtained by numerical models. The Self-Organizing Map (SOM) technique is applied to characterize multi-dimensional wave climate, obtaining the relevant "wave types" spanning the historical variability. This technique summarizes multi-dimension of wave climate in terms of a set of clusters projected in low-dimensional lattice with a spatial organization, providing Probability Density Functions (PDFs) on the lattice. On the other hand, wind and storm surge depend on instantaneous local large-scale sea level pressure (SLP) fields while waves depend on the recent history of these fields (say, 1 to 5 days). Thus, these variables are associated with large-scale atmospheric circulation patterns. In this work, a nearest-neighbors analog method is used to predict monthly multi-dimensional wave climate. This method establishes relationships between the large-scale atmospheric circulation patterns from numerical models (SLP fields as predictors) with local wave databases of observations (monthly wave climate SOM PDFs as predictand) to set up statistical models. A wave reanalysis database, developed by Puertos del Estado (Ministerio de Fomento), is considered as historical time series of local variables. The simultaneous SLP fields calculated by NCEP atmospheric reanalysis are used as predictors. Several applications with different size of sea level pressure grid and with different temporal domain resolution are compared to obtain the optimal statistical model that better represents the monthly wave climate at a particular site. In this work we examine the potential skill of this downscaling approach considering perfect-model conditions, but we will also analyze the
Two-Dimensional Colloidal Alloys
NASA Astrophysics Data System (ADS)
Law, Adam D.; Buzza, D. Martin A.; Horozov, Tommy S.
2011-03-01
We study the structure of mixed monolayers of large (3μm diameter) and small (1μm diameter) very hydrophobic silica particles at an octane-water interface as a function of the number fraction of small particles ξ. We find that a rich variety of two-dimensional hexagonal super-lattices of large (A) and small (B) particles can be obtained in this system due to strong and long-range electrostatic repulsions through the nonpolar octane phase. The structures obtained for the different compositions are in good agreement with zero temperature calculations and finite temperature computer simulations.
Two-dimensional colloidal alloys.
Law, Adam D; Buzza, D Martin A; Horozov, Tommy S
2011-03-25
We study the structure of mixed monolayers of large (3 μm diameter) and small (1 μm diameter) very hydrophobic silica particles at an octane-water interface as a function of the number fraction of small particles ξ. We find that a rich variety of two-dimensional hexagonal super-lattices of large (A) and small (B) particles can be obtained in this system due to strong and long-range electrostatic repulsions through the nonpolar octane phase. The structures obtained for the different compositions are in good agreement with zero temperature calculations and finite temperature computer simulations.
NASA Astrophysics Data System (ADS)
Samardzija, Nikola
1995-01-01
A simple three dimensional physical model is proposed to qualitatively address a particular type of dynamics evolving on toroidal structures. In the phase space this dynamics creates appearance of a worm-hole through which a chaotic, quasiperiodic and periodic behaviors are formed. An intriguing topological property of such a system is that it possesses no steady state solutions. As such, it opens some interesting questions in the bifurcation theory. The model also offers a novel qualitative tool for explaining some recently reported experimental and simulation results observed in physics, chemistry and biology.
Quasicrystalline three-dimensional foams
NASA Astrophysics Data System (ADS)
Cox, S. J.; Graner, F.; Mosseri, R.; Sadoc, J.-F.
2017-03-01
We present a numerical study of quasiperiodic foams, in which the bubbles are generated as duals of quasiperiodic Frank–Kasper phases. These foams are investigated as potential candidates to the celebrated Kelvin problem for the partition of three-dimensional space with equal volume bubbles and minimal surface area. Interestingly, one of the computed structures falls close to (but still slightly above) the best known Weaire–Phelan periodic candidate. In addition we find a correlation between the normalized bubble surface area and the root mean squared deviation of the number of faces, giving an additional clue to understanding the main geometrical ingredients driving the Kelvin problem.
Three-dimensional light bullets
NASA Astrophysics Data System (ADS)
Minardi, S.; Eilenberger, F.; Kartashov, Y. V.; Szameit, A.; Röpke, U.; Kobelke, J.; Schuster, K.; Bartelt, H.; Nolte, S.; Torner, L.; Lederer, F.; Tünnermann, A.; Pertsch, T.
2012-02-01
Three dimensional Light Bullets (3D-LBs) are the most symmetric solitary waves, being nonlinear optical wavepackets propagating without diffraction nor dispersion. Since their theoretical prediction, 3D-LB's have constituted a challenge in nonlinear science, due to the impossibility to avoid catastrophic collapse in conventional homogeneous nonlinear media. We have recently observed stable 3D-LBs in media with periodically modulated transverse refractive index profile. We found that higher order linear and nonlinear effects force the 3D-LBs to evolve along their propagation path and eventually decay. The evolution and decay mechanism entails spatiotemporal effects, which under certain conditions, leads to superluminally propagating wavepackets.
Dimensional regularization in configuration space
Bollini, C.G. |; Giambiagi, J.J.
1996-05-01
Dimensional regularization is introduced in configuration space by Fourier transforming in {nu} dimensions the perturbative momentum space Green functions. For this transformation, the Bochner theorem is used; no extra parameters, such as those of Feynman or Bogoliubov and Shirkov, are needed for convolutions. The regularized causal functions in {ital x} space have {nu}-dependent moderated singularities at the origin. They can be multiplied together and Fourier transformed (Bochner) without divergence problems. The usual ultraviolet divergences appear as poles of the resultant analytic functions of {nu}. Several examples are discussed. {copyright} {ital 1996 The American Physical Society.}
Vortices of Two Dimensional Guiding Center Plasmas.
NASA Astrophysics Data System (ADS)
Ting, Antonio Chofai
A system of two dimensional guiding center plasma in a square conducting boundary is used as a model to study the anomalous transport is magnetically confined plasma. An external gravitational force is introduced to simulate the curvature and gradient of the magnetic field. For finite boundaries, it is a Hamiltonian system with finite phase space and negative temperature states are allowed. The statistical equilibrium states of this system are described by the solutions of a Poisson's equation with self-consistently determined charge density. In the limit of zero gravity, it can be reduced to the sinh-Poisson equation (DEL)('2)u + (lamda)('2)sinh u = 0. Previous numerical efforts have found solutions with vortex structures. A novel method of generating general exact solutions to this nonlinear boundary value problem is presented. These solutions are given by. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI). where E(,i)'s are constants and the dependence of (gamma)(,j)'s on x and y are given by a set of coupled first order nonlinear ordinary differential equations. These equations can be linearized to give u(x,y) in terms of Riemann theta functions u(x,y) = 2ln (THETA)(l + 1/2)(THETA)(l) . The phases l evolve linearly in x and y while nonlinear superposition is displayed in the solution u(x,y). The self-consistent Poisson's equation with gravity is studied numerically. Different branches of solutions are obtained and their relations to the zero gravity solutions are discussed. The thermodynamically most favored structure of the system carries the feature of a heavy ion vortex on top of the light electron vortex. Branches of solutions are found to merge into each other as parameters in the equations were smoothly varied. A critical value of gravitational force exists such that below which there is a possibility of hysteresis between different equilibrium states. With the help of the nonzero gravity solutions, we also have a clearer picture of the transition from
Three-dimensional display technologies
Geng, Jason
2014-01-01
The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) information. This fundamental restriction greatly limits our ability to perceive and to understand the complexity of real-world objects. Nearly 50% of the capability of the human brain is devoted to processing visual information [Human Anatomy & Physiology (Pearson, 2012)]. Flat images and 2D displays do not harness the brain’s power effectively. With rapid advances in the electronics, optics, laser, and photonics fields, true 3D display technologies are making their way into the marketplace. 3D movies, 3D TV, 3D mobile devices, and 3D games have increasingly demanded true 3D display with no eyeglasses (autostereoscopic). Therefore, it would be very beneficial to readers of this journal to have a systematic review of state-of-the-art 3D display technologies. PMID:25530827
Dimensionality Reduction Through Classifier Ensembles
NASA Technical Reports Server (NTRS)
Oza, Nikunj C.; Tumer, Kagan; Norwig, Peter (Technical Monitor)
1999-01-01
In data mining, one often needs to analyze datasets with a very large number of attributes. Performing machine learning directly on such data sets is often impractical because of extensive run times, excessive complexity of the fitted model (often leading to overfitting), and the well-known "curse of dimensionality." In practice, to avoid such problems, feature selection and/or extraction are often used to reduce data dimensionality prior to the learning step. However, existing feature selection/extraction algorithms either evaluate features by their effectiveness across the entire data set or simply disregard class information altogether (e.g., principal component analysis). Furthermore, feature extraction algorithms such as principal components analysis create new features that are often meaningless to human users. In this article, we present input decimation, a method that provides "feature subsets" that are selected for their ability to discriminate among the classes. These features are subsequently used in ensembles of classifiers, yielding results superior to single classifiers, ensembles that use the full set of features, and ensembles based on principal component analysis on both real and synthetic datasets.
Dimensional measurement of sexual deviance.
Hanson, R Karl
2010-04-01
There are at least three approaches by which psychopathology can be described in terms of dimensions. Each approach involves counting the number and severity of symptoms, but these scores have distinct meanings based on whether the latent construct is considered to be categorical or dimensional. Given a categorical construct, dimensions can index either diagnostic certainty or symptom severity. For inherently dimensional constructs, the severity of the symptoms is essentially isomorphic with the underlying latent dimension. The optimal number of dimensions for describing paraphilias is not known, but would likely include features related to problems in sexual self-regulation, the diversity of paraphilic interests, and the overall intensity of sexual drive and expression. Complex measures of these (and related) dimensions currently exist, but simplified criteria are needed for routine communication among diverse mental health professionals. Establishing these criteria would requires professional consensus on the nature of the latent dimensions, as well as reliable assessment of the core constructs using non-arbitrary scales of measurement.
Three-dimensional vortex methods
Greengard, C.A.
1984-08-01
Three-dimensional vortex methods for the computation of incompressible fluid flow are presented from a unified point of view. Reformulations of the filament method and of the method of Beale and Majda show them to be very similar algorithms; in both of them, the vorticity is evaluated by a discretization of the spatial derivative of the flow map. The fact that the filament method, the one which is most often used in practice, can be formulated as a version of the Beale and Majda algorithm in a curved coordinate system is used to give a convergence theorem for the filament method. The method of Anderson is also discussed, in which vorticity is evaluated by the exact differentiation of the approximate velocity field. It is shown that, in the inviscid version of this algorithm, each approximate vector of vorticity remains tangent to a material curve moving with the computed flow, with magnitude proportional to the stretching of this vortex line. This remains true even when time discretization is taken into account. It is explained that the expanding core vortex method converges to a system of equations different from the Navier-Stokes equations. Computations with the filament method of the inviscid interaction of two vortex rings are reported, both with single filaments in each ring and with a fully three-dimensional discretization of vorticity. The dependence on parameters is discussed, and convergence of the computed solutions is observed. 36 references, 4 figures.
ERIC Educational Resources Information Center
Zoreda, Margaret Lee
This paper discusses Wilga Rivers' seven language teaching objectives. Particular focus is on the following three language teaching objectives: (1) giving students the experience of expressing themselves linguistically and culturally in a context different from that in which they grew up; (2) fostering students' understanding of other peoples'…
Marquez, Francisco; Rein, Charles R.; Arias, Oswaldo
1955-01-01
This report deals with the geographical distribution, prevalence, epidemiology, etiology, serological, clinical, and histopathological features, and treatment of mal del pinto, or pinta, in Mexico. Repository penicillin preparations (PAM and Panbiotic) have been found highly effective in the treatment of this endemic, non-venereal treponematosis. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 8 PMID:13260889
One-dimensional Quantum Fluids
NASA Astrophysics Data System (ADS)
Gervais, Guillaume
2015-03-01
Fifty year ago, Joachim Mazdak Luttinger generalized the Tomonaga theory of interactions in a one-dimensional metal and show that the prior restrictions imposed by Tomonaga were not necessary. This model is now known as the Tomonaga- Luttinger liquid model (TLL) and most remarkably it does have mathematically exact solutions. In the case of electrons, it predicts that the spin and charge sector should separate, with each of them propagating with their own velocities. While there has been many attempts (some with great success) to observe TLL behaviour in clean quantum wires designed on an ultra-clean semiconductor platform, overall the Luttinger physics is experimentally still in its infancy. For instance, little is known regarding the 1D physics in a strongly-interacting neutral system, whether from the point-of-view of TLL theory or even localization physics. Helium-4, the paradigm superfluid, and Helium-3, the paradigm Fermi liquid, should in principleboth become Luttinger liquids if taken to the one-dimensional limit. In the bosonic case, this is supported by large-scale Quantum Monte Carlo simulations which found that a lengthscale of ~ 2 nm is sufficient for the system to crossover to the 1D regime and display universal Luttinger scaling. At McGill University, an experiment has been constructed to measure the liquid helium mass flow through a single nanopore. The technique consists of drilling a single nanopore in a SiN membrane using a TEM, and then applying a pressure gradient across the membrane. Previously published data in 45nm diameter hole determined the superfluid critical velocity to be close to the limit set by the Feynman vortex rings model. More recent work performed on nanopores with radii as small as 3 nm (and a length of 30nm) show the critical exponent for superfluid velocity to significantly deviate from its bulk value, 2/3. This is an important hint for the crossing over to the one-dimensional state in a strongly-correlated bosonic liquid.
Dielectric response of metal/SrTiO{sub 3}/two-dimensional electron liquid heterostructures
Mikheev, Evgeny; Raghavan, Santosh; Stemmer, Susanne
2015-08-17
Maximizing the effective dielectric constant of the gate dielectric stack is important for electrostatically controlling high carrier densities inherent to strongly correlated materials. SrTiO{sub 3} is uniquely suited for this purpose, given its extremely high dielectric constant, which can reach 10{sup 4}. Here, we present a systematic study of the thickness dependence of the dielectric response and leakage of SrTiO{sub 3} that is incorporated into a vertical structure on a high-carrier-density two-dimensional electron liquid (2DEL). A simple model can be used to interpret the data. The results show a need for improved interface control in the design of metal/SrTiO{sub 3}/2DEL devices.
Dimensional Reduction for Generalized Continuum Polymers
NASA Astrophysics Data System (ADS)
Helmuth, Tyler
2016-10-01
The Brydges-Imbrie dimensional reduction formula relates the pressure of a d-dimensional gas of hard spheres to a model of (d+2)-dimensional branched polymers. Brydges and Imbrie's proof was non-constructive and relied on a supersymmetric localization lemma. The main result of this article is a constructive proof of a more general dimensional reduction formula that contains the Brydges-Imbrie formula as a special case. Central to the proof are invariance lemmas, which were first introduced by Kenyon and Winkler for branched polymers. The new dimensional reduction formulas rely on invariance lemmas for central hyperplane arrangements that are due to Mészáros and Postnikov. Several applications are presented, notably dimensional reduction formulas for (i) non-spherical bodies and (ii) for corrections to the pressure due to symmetry effects.
Length and Dimensional Measurements at NIST
Swyt, Dennis A.
2001-01-01
This paper discusses the past, present, and future of length and dimensional measurements at NIST. It covers the evolution of the SI unit of length through its three definitions and the evolution of NBS-NIST dimensional measurement from early linescales and gage blocks to a future of atom-based dimensional standards. Current capabilities include dimensional measurements over a range of fourteen orders of magnitude. Uncertainties of measurements on different types of material artifacts range down to 7×10−8 m at 1 m and 8 picometers (pm) at 300 pm. Current work deals with a broad range of areas of dimensional metrology. These include: large-scale coordinate systems; complex form; microform; surface finish; two-dimensional grids; optical, scanning-electron, atomic-force, and scanning-tunneling microscopies; atomic-scale displacement; and atom-based artifacts. PMID:27500015
Dynamic dimensionality reduction for hyperspectral imagery
NASA Astrophysics Data System (ADS)
Safavi, Haleh; Liu, Keng-Hao; Chang, Chein-I.
2011-06-01
Data dimensionality (DR) is generally performed by first fixing size of DR at a certain number, say p and then finding a technique to reduce an original data space to a low dimensional data space with dimensionality specified by p. This paper introduces a new concept of dynamic dimensionality reduction (DDR) which considers the parameter p as a variable by varying the value of p to make p adaptive compared to the commonly used DR, referred to as static dimensionality reduction (SDR) with the parameter p fixed at a constant value. In order to materialize the DDR another new concept, referred to as progressive DR (PDR) is also developed so that the DR can be performed progressively to adapt the variable size of data dimensionality determined by varying the value of p. The advantages of the DDR over SDR are demonstrated through experiments conducted for hyperspectral image classification.
Length and Dimensional Measurements at NIST.
Swyt, D A
2001-01-01
This paper discusses the past, present, and future of length and dimensional measurements at NIST. It covers the evolution of the SI unit of length through its three definitions and the evolution of NBS-NIST dimensional measurement from early linescales and gage blocks to a future of atom-based dimensional standards. Current capabilities include dimensional measurements over a range of fourteen orders of magnitude. Uncertainties of measurements on different types of material artifacts range down to 7×10(-8) m at 1 m and 8 picometers (pm) at 300 pm. Current work deals with a broad range of areas of dimensional metrology. These include: large-scale coordinate systems; complex form; microform; surface finish; two-dimensional grids; optical, scanning-electron, atomic-force, and scanning-tunneling microscopies; atomic-scale displacement; and atom-based artifacts.
Efficient Two-Dimensional-FFT Program
NASA Technical Reports Server (NTRS)
Miko, J.
1992-01-01
Program computes 64 X 64-point fast Fourier transform in less than 17 microseconds. Optimized 64 X 64 Point Two-Dimensional Fast Fourier Transform combines performance of real- and complex-valued one-dimensional fast Fourier transforms (FFT's) to execute two-dimensional FFT and coefficients of power spectrum. Coefficients used in many applications, including analyzing spectra, convolution, digital filtering, processing images, and compressing data. Source code written in C, 8086 Assembly, and Texas Instruments TMS320C30 Assembly languages.
Topics in low-dimensional field theory
Crescimanno, M.J.
1991-04-30
Conformal field theory is a natural tool for understanding two- dimensional critical systems. This work presents results in the lagrangian approach to conformal field theory. The first sections are chiefly about a particular class of field theories called coset constructions and the last part is an exposition of the connection between two-dimensional conformal theory and a three-dimensional gauge theory whose lagrangian is the Chern-Simons density.
Three-dimensional polarization algebra.
R Sheppard, Colin J; Castello, Marco; Diaspro, Alberto
2016-10-01
If light is focused or collected with a high numerical aperture lens, as may occur in imaging and optical encryption applications, polarization should be considered in three dimensions (3D). The matrix algebra of polarization behavior in 3D is discussed. It is useful to convert between the Mueller matrix and two different Hermitian matrices, representing an optical material or system, which are in the literature. Explicit transformation matrices for converting the column vector form of these different matrices are extended to the 3D case, where they are large (81×81) but can be generated using simple rules. It is found that there is some advantage in using a generalization of the Chandrasekhar phase matrix treatment, rather than that based on Gell-Mann matrices, as the resultant matrices are of simpler form and reduce to the two-dimensional case more easily. Explicit expressions are given for 3D complex field components in terms of Chandrasekhar-Stokes parameters.
English Voicing in Dimensional Theory*
Iverson, Gregory K.; Ahn, Sang-Cheol
2007-01-01
Assuming a framework of privative features, this paper interprets two apparently disparate phenomena in English phonology as structurally related: the lexically specific voicing of fricatives in plural nouns like wives or thieves and the prosodically governed “flapping” of medial /t/ (and /d/) in North American varieties, which we claim is itself not a rule per se, but rather a consequence of the laryngeal weakening of fortis /t/ in interaction with speech-rate determined segmental abbreviation. Taking as our point of departure the Dimensional Theory of laryngeal representation developed by Avery & Idsardi (2001), along with their assumption that English marks voiceless obstruents but not voiced ones (Iverson & Salmons 1995), we find that an unexpected connection between fricative voicing and coronal flapping emerges from the interplay of familiar phonemic and phonetic factors in the phonological system. PMID:18496590
Two-dimensional capillary origami
NASA Astrophysics Data System (ADS)
Brubaker, N. D.; Lega, J.
2016-01-01
We describe a global approach to the problem of capillary origami that captures all unfolded equilibrium configurations in the two-dimensional setting where the drop is not required to fully wet the flexible plate. We provide bifurcation diagrams showing the level of encapsulation of each equilibrium configuration as a function of the volume of liquid that it contains, as well as plots representing the energy of each equilibrium branch. These diagrams indicate at what volume level the liquid drop ceases to be attached to the endpoints of the plate, which depends on the value of the contact angle. As in the case of pinned contact points, three different parameter regimes are identified, one of which predicts instantaneous encapsulation for small initial volumes of liquid.
Three-dimensional aromatic networks.
Toyota, Shinji; Iwanaga, Tetsuo
2014-01-01
Three-dimensional (3D) networks consisting of aromatic units and linkers are reviewed from various aspects. To understand principles for the construction of such compounds, we generalize the roles of building units, the synthetic approaches, and the classification of networks. As fundamental compounds, cyclophanes with large aromatic units and aromatic macrocycles with linear acetylene linkers are highlighted in terms of transannular interactions between aromatic units, conformational preference, and resolution of chiral derivatives. Polycyclic cage compounds are constructed from building units by linkages via covalent bonds, metal-coordination bonds, or hydrogen bonds. Large cage networks often include a wide range of guest species in their cavity to afford novel inclusion compounds. Topological isomers consisting of two or more macrocycles are formed by cyclization of preorganized species. Some complicated topological networks are constructed by self-assembly of simple building units.
Three Dimensional Tropical Correspondence Formula
NASA Astrophysics Data System (ADS)
Parker, Brett
2017-07-01
A tropical curve in R3 contributes to Gromov-Witten invariants in all genus. Nevertheless, we present a simple formula for how a given tropical curve contributes to Gromov-Witten invariants when we encode these invariants in a generating function with exponents of {λ} recording Euler characteristic. Our main modification from the known tropical correspondence formula for rational curves is as follows: a trivalent vertex, which before contributed a factor of n to the count of zero-genus holomorphic curves, contributes a factor of {2sin(nλ/2)}. We explain how to calculate relative Gromov-Witten invariants using this tropical correspondence formula, and how to obtain the absolute Gromov-Witten and Donaldson-Thomas invariants of some 3-dimensional toric manifolds including {CP3}. The tropical correspondence formula counting Donaldson-Thomas invariants replaces n by {i^{-(1+n)}q^{n/2}+i^{1+n}q^{-n/2}}.
High-dimensional entanglement certification
Huang, Zixin; Maccone, Lorenzo; Karim, Akib; Macchiavello, Chiara; Chapman, Robert J.; Peruzzo, Alberto
2016-01-01
Quantum entanglement is the ability of joint quantum systems to possess global properties (correlation among systems) even when subsystems have no definite individual property. Whilst the 2-dimensional (qubit) case is well-understood, currently, tools to characterise entanglement in high dimensions are limited. We experimentally demonstrate a new procedure for entanglement certification that is suitable for large systems, based entirely on information-theoretics. It scales more efficiently than Bell’s inequality and entanglement witness. The method we developed works for arbitrarily large system dimension d and employs only two local measurements of complementary properties. This procedure can also certify whether the system is maximally entangled. We illustrate the protocol for families of bipartite states of qudits with dimension up to 32 composed of polarisation-entangled photon pairs. PMID:27311935
Two-dimensional quantum repeaters
NASA Astrophysics Data System (ADS)
Wallnöfer, J.; Zwerger, M.; Muschik, C.; Sangouard, N.; Dür, W.
2016-11-01
The endeavor to develop quantum networks gave rise to a rapidly developing field with far-reaching applications such as secure communication and the realization of distributed computing tasks. This ultimately calls for the creation of flexible multiuser structures that allow for quantum communication between arbitrary pairs of parties in the network and facilitate also multiuser applications. To address this challenge, we propose a two-dimensional quantum repeater architecture to establish long-distance entanglement shared between multiple communication partners in the presence of channel noise and imperfect local control operations. The scheme is based on the creation of self-similar multiqubit entanglement structures at growing scale, where variants of entanglement swapping and multiparty entanglement purification are combined to create high-fidelity entangled states. We show how such networks can be implemented using trapped ions in cavities.
Three-dimensional coil inductor
Bernhardt, Anthony F.; Malba, Vincent
2002-01-01
A three-dimensional coil inductor is disclosed. The inductor includes a substrate; a set of lower electrically conductive traces positioned on the substrate; a core placed over the lower traces; a set of side electrically conductive traces laid on the core and the lower traces; and a set of upper electrically conductive traces attached to the side traces so as to form the inductor. Fabrication of the inductor includes the steps of forming a set of lower traces on a substrate; positioning a core over the lower traces; forming a set of side traces on the core; connecting the side traces to the lower traces; forming a set of upper traces on the core; and connecting the upper traces to the side traces so as to form a coil structure.
Three-dimensional vortex methods
NASA Astrophysics Data System (ADS)
Greengard, C. A.
1984-08-01
Reformulations of the filament method and of the method of Beale and Majda show them to be very similar algorithms. The method of Anderson in which vorticity is evaluated by the exact differentiation of the approximate velocity field is discussed. It is shown that, in the inviscid version of this algorithm, each approximate vector of vorticity remains tangent to a material curve moving with the computed flow, with magnitude proportional to the stretching of this vortex line. It is explained that the expanding core vortex method converges to a system of equations different from the Navier-Stokes equations. Computations with the filament method of the inviscid interaction of two vortex rings are reported, both with single filaments in each ring and with a fully three-dimensional discretization of vorticity. The dependence on parameters is discussed, and convergence of the computed solutions is observed.
Four Dimensional Trace Space Measurement
Hernandez, M.
2005-02-10
Future high energy colliders and FELs (Free Electron Lasers) such as the proposed LCLS (Linac Coherent Light Source) at SLAC require high brightness electron beams. In general a high brightness electron beam will contain a large number of electrons that occupy a short longitudinal duration, can be focused to a small transverse area while having small transverse divergences. Therefore the beam must have a high peak current and occupy small areas in transverse phase space and so have small transverse emittances. Additionally the beam should propagate at high energy and have a low energy spread to reduce chromatic effects. The requirements of the LCLS for example are pulses which contain 10{sup 10} electrons in a temporal duration of 10 ps FWHM with projected normalized transverse emittances of 1{pi} mm mrad[1]. Currently the most promising method of producing such a beam is the RF photoinjector. The GTF (Gun Test Facility) at SLAC was constructed to produce and characterize laser and electron beams which fulfill the LCLS requirements. Emittance measurements of the electron beam at the GTF contain evidence of strong coupling between the transverse dimensions of the beam. This thesis explores the effects of this coupling on the determination of the projected emittances of the electron beam. In the presence of such a coupling the projected normalized emittance is no longer a conserved quantity. The conserved quantity is the normalized full four dimensional phase space occupied by the beam. A method to determine the presence and evaluate the strength of the coupling in emittance measurements made in the laboratory is developed. A method to calculate the four dimensional volume the beam occupies in phase space using quantities available in the laboratory environment is also developed. Results of measurements made of the electron beam at the GTF that demonstrate these concepts are presented and discussed.
Equivariant dimensional reduction and quiver gauge theories
NASA Astrophysics Data System (ADS)
Dolan, Brian P.; Szabo, Richard J.
2011-09-01
We review recent applications of equivariant dimensional reduction techniques to the construction of Yang-Mills-Higgs-Dirac theories with dynamical mass generation and exactly massless chiral fermions.
[Three-dimensional printing and oral medicine].
Hu, M
2017-04-09
After 30 years of development, three-dimensional printing technology has made great progress, and the model and surgical guide have been clinically applied. The three-dimensional printing of titanium and other metal prosthesis and dental crown after adequate research will be applied clinically, and three-dimensional bioprinting and related biological materials need further study. Three-dimensional printing provides opportunities for the development of oral medicine, which will change the way of clinical work, teaching and research. The dentists should integrate multi-disciplinary knowledge and understand the essence of new technology to meet the challenges of the era of digital medicine.
Sparse High Dimensional Models in Economics
Fan, Jianqing; Lv, Jinchi; Qi, Lei
2010-01-01
This paper reviews the literature on sparse high dimensional models and discusses some applications in economics and finance. Recent developments of theory, methods, and implementations in penalized least squares and penalized likelihood methods are highlighted. These variable selection methods are proved to be effective in high dimensional sparse modeling. The limits of dimensionality that regularization methods can handle, the role of penalty functions, and their statistical properties are detailed. Some recent advances in ultra-high dimensional sparse modeling are also briefly discussed. PMID:22022635
One- and two-dimensional hydrogen atoms
NASA Astrophysics Data System (ADS)
Hassoun, G. Q.
1981-02-01
Certain one- and two-dimensional reductions of the three-dimensional Schrödinger equation of the hydrogen atom are considered. These reductions are carried out from the point of view of the two common sets of space coordinates: Cartesian and spherical. The resulting systems have features that relate more readily to the old quantum theory models of Bohr and Sommerfeld than the general three-dimensional hydrogen atom. Furthermore, the considerations yield interesting insights into the quantum mechanics of the hydrogen atom and may serve as helpful intermediary preparation, in an introductory presentation of the subject, for the unreduced three-dimensional case.
Dimensional Hierarchy of Fermionic Interacting Topological Phases.
Queiroz, Raquel; Khalaf, Eslam; Stern, Ady
2016-11-11
We present a dimensional reduction argument to derive the classification reduction of fermionic symmetry protected topological phases in the presence of interactions. The dimensional reduction proceeds by relating the topological character of a d-dimensional system to the number of zero-energy bound states localized at zero-dimensional topological defects present at its surface. This correspondence leads to a general condition for symmetry preserving interactions that render the system topologically trivial, and allows us to explicitly write a quartic interaction to this end. Our reduction shows that all phases with topological invariant smaller than n are topologically distinct, thereby reducing the noninteracting Z classification to Z_{n}.
Dimensionality Reduction Library v 0.2
BROWN, WILLIAM; MARTIN, SHAWN; WATSON, JEAN-PAUL; & JIA, HAIXIA
2009-06-12
Dimensionality Reduction Library is a C++ library for dimensionality reduction. In the context of this library, dimensionality reduction is considered to consist of 1)estimation of the intrinsic dimensionality using sampled data, 2) Finding maps that reduce the diemsionality of data (forward map) or increase the dimensionality of data (reverse map) and 3) mapping arbitray coordiantes to high and low dimensionalities. The library is intended toprovide a consistent interface to multiple dimensionality reduction algorithms with an efficient C++ interface that runs efficiently on multicore architectures. A few routines have been optimized with an option for GPU acceleration or distributed computation. Currently the library offers intrinsic dimensionality estimation using point-PCA reconstruction error and/ residual variance. The following dimensionality reduction methods have been implemented: Principal Component Analysis Multidimensional Scaling Locally Linear Embedding IsoMap Autoencoder Neutral Networks An executable is also supplied that can be built to allow for command-line access to the library routines. A description for an applciation of the library for molecular structure analysis has been published.
Dimensional Hierarchy of Fermionic Interacting Topological Phases
NASA Astrophysics Data System (ADS)
Queiroz, Raquel; Khalaf, Eslam; Stern, Ady
2016-11-01
We present a dimensional reduction argument to derive the classification reduction of fermionic symmetry protected topological phases in the presence of interactions. The dimensional reduction proceeds by relating the topological character of a d -dimensional system to the number of zero-energy bound states localized at zero-dimensional topological defects present at its surface. This correspondence leads to a general condition for symmetry preserving interactions that render the system topologically trivial, and allows us to explicitly write a quartic interaction to this end. Our reduction shows that all phases with topological invariant smaller than n are topologically distinct, thereby reducing the noninteracting Z classification to Zn.
Tierra del Fuego, Argentina, South America
NASA Technical Reports Server (NTRS)
1991-01-01
The Mitre Peninsula is the easternmost tip of Tierra del Fuego, Argentina, (54.5S, 65.5W). Early winter snow can be seen on this south tip of the Andes Mountains. These same mountains continue underwater to Antarctica. The Strait of Magellan, separating the South American mainland from Tierra del Fuego is off the scene to the north and west, but the Strait of LeMaire, separating Tierra del Fuego from the Isla de los Estados can be seen.
Electromagnetically Inferred Structure of the Caja del Rio Plateau, New Mexico
NASA Astrophysics Data System (ADS)
Layton, M. E.; Speed, C.; Shukla, M.; Vila, A.; Chon, E.; Kitamikado, C.; Feucht, D. W.; Bedrosian, P.; Pellerin, L.
2016-12-01
Magnetotelluric (MT) and transient electromagnetic (TEM) data were acquired by students from the Summer of Applied Geophysical Experience (SAGE) to construct structural models in and around the Caja del Rio Plateau, New Mexico. The Caja del Rio is located on the La Bajada-Jemez constriction that separates the Española and Santa Domingo basins in the Rio Grande Rift. The Rio Grande Rift, the result of tectonic extensional forces, extends approximately north-south across northern New Mexico. MT data collected in 2016 were merged with that from previous years to make up an 11 km north line and a 16 km south line extending from the west side of the Caja Del Rio to the east off the plateau in the Old Buckman Road area. The resistivity distributions revealed in one-dimensional (1-D) and two-dimensional (2-D) inverse models show some robust features. Models of the north are interpreted as a top resistive layer (<500m) of Tertiary volcanoclastic rock, to a central conductive layer (600-200m) of Mesozoic and Paleozoic sediments of the Santa Fe group to crystalline basement rock. Models for the south line show low resistivity for the first 3 to 5 km and then transitions into higher resistivity values consistent with the models for the north line. At a period of 100 seconds induction arrows (Parkinson's convention) point in the northwest direction towards the conductive Valles Caldera. The MT models are consistent with geologic interpretations of the stratigraphic units. In addition, models disclose an additional conductive layer below the basement that we interpret as the mid-crustal conductor. Transient electromagnetic (TEM) data were collected in seven locations atop the Caja del Rio plateau in an attempt to identify the basal contact of the Cerros del Rio volcanic field, which, in turn, allow for the thickness of these basaltic and andesitic deposits to be mapped across the plateau. One-dimensional inverse models produced from the TEM data were aligned and interpreted
33 CFR 80.1118 - Marina Del Rey, CA.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Marina Del Rey, CA. 80.1118... NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1118 Marina Del Rey, CA. (a) A line drawn from Marina Del Rey Breakwater South Light 1 to Marina Del Rey Light 4. (b) A line drawn from Marina Del...
NASA Astrophysics Data System (ADS)
Reynolds, M. D.
1990-01-01
Student pairs were provided cards depicting two cycles of lunar phases; Pairs who used three-dimensional models to explain phases were more likely to have a scientifically accurate explanation than those who used two-dimensional models.
Chen, Leiming; Lee, Chiu Fan; Toner, John
2016-07-25
Active fluids and growing interfaces are two well-studied but very different non-equilibrium systems. Each exhibits non-equilibrium behaviour distinct from that of their equilibrium counterparts. Here we demonstrate a surprising connection between these two: the ordered phase of incompressible polar active fluids in two spatial dimensions without momentum conservation, and growing one-dimensional interfaces (that is, the 1+1-dimensional Kardar-Parisi-Zhang equation), in fact belong to the same universality class. This universality class also includes two equilibrium systems: two-dimensional smectic liquid crystals, and a peculiar kind of constrained two-dimensional ferromagnet. We use these connections to show that two-dimensional incompressible flocks are robust against fluctuations, and exhibit universal long-ranged, anisotropic spatio-temporal correlations of those fluctuations. We also thereby determine the exact values of the anisotropy exponent ζ and the roughness exponents χx,y that characterize these correlations.
Mapping two-dimensional polar active fluids to two-dimensional soap and one-dimensional sandblasting
NASA Astrophysics Data System (ADS)
Chen, Leiming; Lee, Chiu Fan; Toner, John
2016-07-01
Active fluids and growing interfaces are two well-studied but very different non-equilibrium systems. Each exhibits non-equilibrium behaviour distinct from that of their equilibrium counterparts. Here we demonstrate a surprising connection between these two: the ordered phase of incompressible polar active fluids in two spatial dimensions without momentum conservation, and growing one-dimensional interfaces (that is, the 1+1-dimensional Kardar-Parisi-Zhang equation), in fact belong to the same universality class. This universality class also includes two equilibrium systems: two-dimensional smectic liquid crystals, and a peculiar kind of constrained two-dimensional ferromagnet. We use these connections to show that two-dimensional incompressible flocks are robust against fluctuations, and exhibit universal long-ranged, anisotropic spatio-temporal correlations of those fluctuations. We also thereby determine the exact values of the anisotropy exponent ζ and the roughness exponents χx,y that characterize these correlations.
Mapping two-dimensional polar active fluids to two-dimensional soap and one-dimensional sandblasting
Chen, Leiming; Lee, Chiu Fan; Toner, John
2016-01-01
Active fluids and growing interfaces are two well-studied but very different non-equilibrium systems. Each exhibits non-equilibrium behaviour distinct from that of their equilibrium counterparts. Here we demonstrate a surprising connection between these two: the ordered phase of incompressible polar active fluids in two spatial dimensions without momentum conservation, and growing one-dimensional interfaces (that is, the 1+1-dimensional Kardar–Parisi–Zhang equation), in fact belong to the same universality class. This universality class also includes two equilibrium systems: two-dimensional smectic liquid crystals, and a peculiar kind of constrained two-dimensional ferromagnet. We use these connections to show that two-dimensional incompressible flocks are robust against fluctuations, and exhibit universal long-ranged, anisotropic spatio-temporal correlations of those fluctuations. We also thereby determine the exact values of the anisotropy exponent ζ and the roughness exponents χx,y that characterize these correlations. PMID:27452107
Three Dimensional Illustrating--Three-Dimensional Vision and Deception of Sensibility
ERIC Educational Resources Information Center
Szállassy, Noémi; Gánóczy, Anita; Kriska, György
2009-01-01
The wide-spread digital photography and computer use gave the opportunity for everyone to make three-dimensional pictures and to make them public. The new opportunities with three-dimensional techniques give chance for the birth of new artistic photographs. We present in detail the biological roots of three-dimensional visualization, the phenomena…
Three-dimensional gravity and string ghosts
Carlip, S. ); Kogan, I.I. )
1991-12-23
It is known that much of the structure of string theory can be derived from three-dimensional topological field theory and gravity. We show here that, at least for simple topologies, the string diffeomorphism ghosts can also be explained in terms of three-dimensional physics.
Teleportation schemes in infinite dimensional Hilbert spaces
Fichtner, Karl-Heinz; Freudenberg, Wolfgang; Ohya, Masanori
2005-10-01
The success of quantum mechanics is due to the discovery that nature is described in infinite dimension Hilbert spaces, so that it is desirable to demonstrate the quantum teleportation process in a certain infinite dimensional Hilbert space. We describe the teleportation process in an infinite dimensional Hilbert space by giving simple examples.
Dimensionality reduction in epidemic spreading models
NASA Astrophysics Data System (ADS)
Frasca, M.; Rizzo, A.; Gallo, L.; Fortuna, L.; Porfiri, M.
2015-09-01
Complex dynamical systems often exhibit collective dynamics that are well described by a reduced set of key variables in a low-dimensional space. Such a low-dimensional description offers a privileged perspective to understand the system behavior across temporal and spatial scales. In this work, we propose a data-driven approach to establish low-dimensional representations of large epidemic datasets by using a dimensionality reduction algorithm based on isometric features mapping (ISOMAP). We demonstrate our approach on synthetic data for epidemic spreading in a population of mobile individuals. We find that ISOMAP is successful in embedding high-dimensional data into a low-dimensional manifold, whose topological features are associated with the epidemic outbreak. Across a range of simulation parameters and model instances, we observe that epidemic outbreaks are embedded into a family of closed curves in a three-dimensional space, in which neighboring points pertain to instants that are close in time. The orientation of each curve is unique to a specific outbreak, and the coordinates correlate with the number of infected individuals. A low-dimensional description of epidemic spreading is expected to improve our understanding of the role of individual response on the outbreak dynamics, inform the selection of meaningful global observables, and, possibly, aid in the design of control and quarantine procedures.
Effects of phosphoramides on wood dimensional stability
Hong-Lin. Lee; George C. Chen; Roger M. Rowell
2000-01-01
To evaluate the dimensional stability of phosphoramide-reacted wood, wood was reacted with a mixture which was derived from compounding phosphorus pentoxide and each of 12 amines including alkyl, halophenyl, and phenyl amines in N,N-dimethylformamide. Dimensional stability of such reacted wood was analyzed by antishrink efficiency (ASE) using the water-soak method....
Three-Dimensional Co-Culture Process
NASA Technical Reports Server (NTRS)
Goodwin, Thomas J. (Inventor); Wolf, David A. (Inventor)
1997-01-01
By the process of the present invention a variety of cells may be co-cultured to produce tissue which has 3-dimensionality and had some of the characteristics of in vivo tissue. The process provides enhanced 3-dimensional tissue which creates a multicellular organoid differentiation model.
Microlaser-based three-dimensional display
NASA Astrophysics Data System (ADS)
Takeuchi, Eric B.; Bergstedt, Robert; Hargis, David E.; Higley, Paul D.
1999-08-01
Three dimensional (3D) displays are critical for viewing complex multi-dimensional information and for viewing representations of the three dimensional real world. A teaming arrangement between Laser Power Corporation (LPC) and Specialty Devices, Inc. (SDI) has led to the feasibility demonstration of a directly-viewed three dimensional volumetric display. LPC has developed red, green, and blue (RGB) diode pumped solid state microlaser display technology for use as a high resolution, high brightness display engine for the three dimensional display. Concurrently, SDI has developed a unique technology for viewing high resolution three dimensional volumetric images without external viewing aids (eye wear). When coupled to LPC's display engine, the resultant all solid state three dimensional display presets a true, physical three dimensionality which is directly viewable from all angles by multiple viewers without additional viewing equipment (eye wear). The resultant volumetric display will further enable applications such as the 'virtual sandbox,' visualization of radar and sonar data, air traffic control, remote surgery and diagnostics, and CAD workstations.
Algorithmic dimensionality reduction for molecular structure analysis.
Brown, W Michael; Martin, Shawn; Pollock, Sara N; Coutsias, Evangelos A; Watson, Jean-Paul
2008-08-14
Dimensionality reduction approaches have been used to exploit the redundancy in a Cartesian coordinate representation of molecular motion by producing low-dimensional representations of molecular motion. This has been used to help visualize complex energy landscapes, to extend the time scales of simulation, and to improve the efficiency of optimization. Until recently, linear approaches for dimensionality reduction have been employed. Here, we investigate the efficacy of several automated algorithms for nonlinear dimensionality reduction for representation of trans, trans-1,2,4-trifluorocyclo-octane conformation--a molecule whose structure can be described on a 2-manifold in a Cartesian coordinate phase space. We describe an efficient approach for a deterministic enumeration of ring conformations. We demonstrate a drastic improvement in dimensionality reduction with the use of nonlinear methods. We discuss the use of dimensionality reduction algorithms for estimating intrinsic dimensionality and the relationship to the Whitney embedding theorem. Additionally, we investigate the influence of the choice of high-dimensional encoding on the reduction. We show for the case studied that, in terms of reconstruction error root mean square deviation, Cartesian coordinate representations and encodings based on interatom distances provide better performance than encodings based on a dihedral angle representation.
Dimension and dimensional reduction in quantum gravity
NASA Astrophysics Data System (ADS)
Carlip, S.
2017-10-01
A number of very different approaches to quantum gravity contain a common thread, a hint that spacetime at very short distances becomes effectively two dimensional. I review this evidence, starting with a discussion of the physical meaning of ‘dimension’ and concluding with some speculative ideas of what dimensional reduction might mean for physics.
Measuring Monotony in Two-Dimensional Samples
ERIC Educational Resources Information Center
Kachapova, Farida; Kachapov, Ilias
2010-01-01
This note introduces a monotony coefficient as a new measure of the monotone dependence in a two-dimensional sample. Some properties of this measure are derived. In particular, it is shown that the absolute value of the monotony coefficient for a two-dimensional sample is between /"r"/ and 1, where "r" is the Pearson's…
Using Del-1 to Tip the Angiogenic Balance in Endothelial Cells in Modular Constructs
Ciucurel, Ema C.; Vlahos, Alexander E.
2014-01-01
Modular tissue engineering is a method of building vascularized tissue-engineered constructs. Submillimeter-sized collagen pieces (modules) coated with a layer of endothelial cells (EC; vascular component), and with embedded functional cells, are self-assembled into a larger, three-dimensional tissue. In this study, we examined the use of developmental endothelial locus-1 (Del-1), an extracellular matrix protein with proangiogenic properties, as a means of tipping the angiogenic balance in human umbilical vein endothelial cells incorporated in modular tissue-engineered constructs. The motivation was to enhance the vascularization of these constructs upon transplantation in vivo, in this case, without the use of exogenous mesenchymal stromal cells. EC were transduced using a lentiviral construct to overexpress Del-1. The Del-1 EC formed more sprouts in a fibrin gel sprouting assay in vitro compared with eGFP (control) transduced EC, as expected. Del-1 EC had a distinct profile of gene expression (upregulation of matrix metalloproteinase-9 [MMP-9], urokinase-type plasminogen activator [uPA/PLAU], vascular endothelial growth factor [VEGF-A], and intercellular adhesion molecule-1 [ICAM-1]; downregulation of angiopoietin-2 [Ang2]), also supporting the notion of “tipping the angiogenic balance”. On the other hand, contrary to our expectations, when Del-1 EC-coated modules were implanted subcutaneously in a severe combined immunodeficient/beige animal model, the proangiogenic effect of Del-1 was less remarkable. There was only a small increase in the number of blood vessels formed in Del-1 implants compared with the eGFP implants, and only few blood vessels formed at the implant site in both cases. This was presumed due to limited EC survival after transplantation. We speculate that if we could improve EC survival in our study (for example, by adding other prosurvival factors or supporting cells), we would see a greater Del-1-induced angiogenic benefit in vivo as a
Extra-dimensional models on the lattice
Knechtli, Francesco; Rinaldi, Enrico
2016-08-05
In this paper we summarize the ongoing effort to study extra-dimensional gauge theories with lattice simulations. In these models the Higgs field is identified with extra-dimensional components of the gauge field. The Higgs potential is generated by quantum corrections and is protected from divergences by the higher dimensional gauge symmetry. Dimensional reduction to four dimensions can occur through compactification or localization. Gauge-Higgs unification models are often studied using perturbation theory. Numerical lattice simulations are used to go beyond these perturbative expectations and to include nonperturbative effects. We describe the known perturbative predictions and their fate in the strongly-coupled regime formore » various extra-dimensional models.« less
Three-dimensional stability of vortex arrays
NASA Astrophysics Data System (ADS)
Robinson, A. C.; Saffman, P. G.
1982-12-01
The stability to three-dimensional disturbances of three classical steady vortex configurations in an incompressible inviscid fluid is studied in the limit of small vortex cross-sectional area and long axial disturbance wavelength. The configurations examined are the single infinite vortex row, the Karman vortex street of staggered vortices and the symmetric vortex street. It is shown that the single row is most unstable to a two-dimensional disturbance, while the Karman vortex street is most unstable to a three-dimensional disturbance over a significant range of street spacing ratios. The symmetric vortex street is found to be most unstable to three-dimensional or two-dimensional symmetric disturbances depending on the spacing ratio of the street. Short remarks are made concerning the relevance of the calculations to the observed instabilities in free shear layer, wake and boundary-layer type flows.
Two Dimensional Plasmonic Cavities on Moire Surfaces
NASA Astrophysics Data System (ADS)
Balci, Sinan; Kocabas, Askin; Karabiyik, Mustafa; Kocabas, Coskun; Aydinli, Atilla
2010-03-01
We investigate surface plasmon polariton (SPP) cavitiy modes on two dimensional Moire surfaces in the visible spectrum. Two dimensional hexagonal Moire surface can be recorded on a photoresist layer using Interference lithography (IL). Two sequential exposures at slightly different angles in IL generate one dimensional Moire surfaces. Further sequential exposure for the same sample at slightly different angles after turning the sample 60 degrees around its own axis generates two dimensional hexagonal Moire cavity. Spectroscopic reflection measurements have shown plasmonic band gaps and cavity states at all the azimuthal angles (omnidirectional cavity and band gap formation) investigated. The plasmonic band gap edge and the cavity states energies show six fold symmetry on the two dimensional Moire surface as measured in reflection measurements.
The Physics of Low-dimensional Semiconductors
NASA Astrophysics Data System (ADS)
Davies, John H.
1997-12-01
Low-dimensional systems have revolutionized semiconductor physics and had a tremendous impact on technology. Using simple physical explanations, with reference to examples from actual devices, this book introduces the general principles essential to low-dimensional semiconductors. The author presents a formalism that describes low-dimensional semiconductor systems, studying two key systems in detail: the two-dimensional electron gas, employed in field-effect transistors, and the quantum well, whose optical properties have multiple applications in lasers and other opto-electronic devices. The book will be invaluable to undergraduate and first-year graduate physics or electrical engineering students taking courses in low-dimensional systems or heterostructure device physics.
Multi-dimensional edge detection operators
NASA Astrophysics Data System (ADS)
Youn, Sungwook; Lee, Chulhee
2014-05-01
In remote sensing, modern sensors produce multi-dimensional images. For example, hyperspectral images contain hundreds of spectral images. In many image processing applications, segmentation is an important step. Traditionally, most image segmentation and edge detection methods have been developed for one-dimensional images. For multidimensional images, the output images of spectral band images are typically combined under certain rules or using decision fusions. In this paper, we proposed a new edge detection algorithm for multi-dimensional images using secondorder statistics. First, we reduce the dimension of input images using the principal component analysis. Then we applied multi-dimensional edge detection operators that utilize second-order statistics. Experimental results show promising results compared to conventional one-dimensional edge detectors such as Sobel filter.
Three-dimensional metallic boron nitride.
Zhang, Shunhong; Wang, Qian; Kawazoe, Yoshiyuki; Jena, Puru
2013-12-04
Boron nitride (BN) and carbon are chemical analogues of each other and share similar structures such as one-dimensional nanotubes, two-dimensional nanosheets characterized by sp(2) bonding, and three-dimensional diamond structures characterized by sp(3) bonding. However, unlike carbon which can be metallic in one, two, and three dimensions, BN is an insulator, irrespective of its structure and dimensionality. On the basis of state-of-the-art theoretical calculations, we propose a tetragonal phase of BN which is both dynamically stable and metallic. Analysis of its band structure, density of states, and electron localization function confirms the origin of the metallic behavior to be due to the delocalized B 2p electrons. The metallicity exhibited in the studied three-dimensional BN structures can lead to materials beyond conventional ceramics as well as to materials with potential for applications in electronic devices.
Comparison of two-dimensional and three-dimensional echocardiographic strain in children with CHD.
Wisotzkey, Bethany L; Soriano, Brian D; Buddhe, Sujatha
2017-10-01
In CHD, three-dimensional strain analysis may overcome limitations of Doppler and two-dimensional strain of the left ventricle. The aims of this study were to evaluate feasibility and reproducibility of three-dimensional longitudinal, circumferential, and radial systolic strain by three-dimensional speckle-tracking echocardiography compared with two-dimensional echocardiography. Patients with CHD, biventricular circulation with a systemic left ventricle, and who had two- and three-dimensional imaging performed on the same day from 2010 to 2014 were included. Quantitative two- and three-dimensional strain analyses were performed (two-dimensional cardiac performance analysis version 1.2 and four-dimensional left ventricular analysis version 3.1). Intra- and inter-observer variabilities were calculated on 25 studies. A total of 30 patients, including 19 (61%) males, with a median age of 3.6 years (0.1-22 years) were included. The mean fractional shortening was 34.6±5.3%, and the mean ejection fraction was 62.0±6.4%. Measurement of two- and three-dimensional strain was feasible in >95% of segments. Good correlation was observed between longitudinal and circumferential strain (r=0.92, p⩽0.001 and r=0.87, p⩽0.001), but not radial strain (r=0.29, p=0.2). Intra- and inter-observer agreements were better for three-dimensional compared with two-dimensional strain, and better for both two- and three-dimensional longitudinal and circumferential strains compared with radial strain. Left ventricular three-dimensional strain analysis is feasible in children with CHD. The reproducibility of longitudinal and circumferential strain by three-dimensional analyses is better. Further longitudinal studies are warranted for the potential clinical application of this new technology.
Three-dimensional colloidal lithography.
Nagai, Hironori; Poteet, Austen; Zhang, Xu A; Chang, Chih-Hao
2017-03-24
Light interactions with colloidal particles can generate a variety of complex three-dimensional (3D) intensity patterns, which can be utilized for nanolithography. The study of particle-light interactions can add more types of intensity patterns by manipulating key factors. Here we investigate a novel 3D nanolithography technique using colloidal particles under two-beam coherent illuminations. The fabricated 3D nanostructures are hollow, nested within periodic structures, and possess multiple chamber geometry. The effects of incident angles and particle size on the fabricated nanostructures were examined. The relative phase shift between particle position and interference pattern is identified as another significant parameter influencing the resultant nanostructures. A numerical model has been developed to show the evolution of nanostructure geometry with phase shifts, and experimental studies confirm the simulation results. Through the introduction of single colloidal particles, the fabrication capability of Lloyd's mirror interference can now be extended to fabrication of 3D nanostructure with complex shell geometry. The fabricated hollow nanostructures with grating background could find potential applications in the area of photonics, drug delivery, and nanofluidics.
Three-dimensional colloidal lithography
NASA Astrophysics Data System (ADS)
Nagai, Hironori; Poteet, Austen; Zhang, Xu A.; Chang, Chih-Hao
2017-03-01
Light interactions with colloidal particles can generate a variety of complex three-dimensional (3D) intensity patterns, which can be utilized for nanolithography. The study of particle-light interactions can add more types of intensity patterns by manipulating key factors. Here we investigate a novel 3D nanolithography technique using colloidal particles under two-beam coherent illuminations. The fabricated 3D nanostructures are hollow, nested within periodic structures, and possess multiple chamber geometry. The effects of incident angles and particle size on the fabricated nanostructures were examined. The relative phase shift between particle position and interference pattern is identified as another significant parameter influencing the resultant nanostructures. A numerical model has been developed to show the evolution of nanostructure geometry with phase shifts, and experimental studies confirm the simulation results. Through the introduction of single colloidal particles, the fabrication capability of Lloyd’s mirror interference can now be extended to fabrication of 3D nanostructure with complex shell geometry. The fabricated hollow nanostructures with grating background could find potential applications in the area of photonics, drug delivery, and nanofluidics.
Four-dimensional electron microscopy.
Zewail, Ahmed H
2010-04-09
The discovery of the electron over a century ago and the realization of its dual character have given birth to one of the two most powerful imaging instruments: the electron microscope. The electron microscope's ability to resolve three-dimensional (3D) structures on the atomic scale is continuing to affect different fields, including materials science and biology. In this Review, we highlight recent developments and inventions made by introducing the fourth dimension of time in electron microscopy. Today, ultrafast electron microscopy (4D UEM) enables a resolution that is 10 orders of magnitude better than that of conventional microscopes, which are limited by the video-camera rate of recording. After presenting the central concept involved, that of single-electron stroboscopic imaging, we discuss prototypical applications, which include the visualization of complex structures when unfolding on different length and time scales. The developed UEM variant techniques are several, and here we illucidate convergent-beam and near-field imaging, as well as tomography and scanning-pulse microscopy. We conclude with current explorations in imaging of nanomaterials and biostructures and an outlook on possible future directions in space-time, 4D electron microscopy.
Three-dimensional laser microvision.
Shimotahira, H; Iizuka, K; Chu, S C; Wah, C; Costen, F; Yoshikuni, Y
2001-04-10
A three-dimensional (3-D) optical imaging system offering high resolution in all three dimensions, requiring minimum manipulation and capable of real-time operation, is presented. The system derives its capabilities from use of the superstructure grating laser source in the implementation of a laser step frequency radar for depth information acquisition. A synthetic aperture radar technique was also used to further enhance its lateral resolution as well as extend the depth of focus. High-speed operation was made possible by a dual computer system consisting of a host and a remote microcomputer supported by a dual-channel Small Computer System Interface parallel data transfer system. The system is capable of operating near real time. The 3-D display of a tunneling diode, a microwave integrated circuit, and a see-through image taken by the system operating near real time are included. The depth resolution is 40 mum; lateral resolution with a synthetic aperture approach is a fraction of a micrometer and that without it is approximately 10 mum.
Three-Dimensional Laser Microvision
NASA Astrophysics Data System (ADS)
Shimotahira, Hiroshi; Iizuka, Keigo; Chu, Sun-Chun; Wah, Christopher; Costen, Furnie; Yoshikuni, Yuzo
2001-04-01
A three-dimensional (3-D) optical imaging system offering high resolution in all three dimensions, requiring minimum manipulation and capable of real-time operation, is presented. The system derives its capabilities from use of the superstructure grating laser source in the implementation of a laser step frequency radar for depth information acquisition. A synthetic aperture radar technique was also used to further enhance its lateral resolution as well as extend the depth of focus. High-speed operation was made possible by a dual computer system consisting of a host and a remote microcomputer supported by a dual-channel Small Computer System Interface parallel data transfer system. The system is capable of operating near real time. The 3-D display of a tunneling diode, a microwave integrated circuit, and a see-through image taken by the system operating near real time are included. The depth resolution is 40 m; lateral resolution with a synthetic aperture approach is a fraction of a micrometer and that without it is approximately 10 m.
The addictive dimensionality of obesity.
Volkow, Nora D; Wang, Gene-Jack; Tomasi, Dardo; Baler, Ruben D
2013-05-01
Our brains are hardwired to respond and seek immediate rewards. Thus, it is not surprising that many people overeat, which in some can result in obesity, whereas others take drugs, which in some can result in addiction. Though food intake and body weight are under homeostatic regulation, when highly palatable food is available, the ability to resist the urge to eat hinges on self-control. There is no homeostatic regulator to check the intake of drugs (including alcohol); thus, regulation of drug consumption is mostly driven by self-control or unwanted effects (i.e., sedation for alcohol). Disruption in both the neurobiological processes that underlie sensitivity to reward and those that underlie inhibitory control can lead to compulsive food intake in some individuals and compulsive drug intake in others. There is increasing evidence that disruption of energy homeostasis can affect the reward circuitry and that overconsumption of rewarding food can lead to changes in the reward circuitry that result in compulsive food intake akin to the phenotype seen with addiction. Addiction research has produced new evidence that hints at significant commonalities between the neural substrates underlying the disease of addiction and at least some forms of obesity. This recognition has spurred a healthy debate to try and ascertain the extent to which these complex and dimensional disorders overlap and whether or not a deeper understanding of the crosstalk between the homeostatic and reward systems will usher in unique opportunities for prevention and treatment of both obesity and drug addiction.
Two-dimensional Quantum Gravity
NASA Astrophysics Data System (ADS)
Rolf, Juri
1998-10-01
This Ph.D. thesis pursues two goals: The study of the geometrical structure of two-dimensional quantum gravity and in particular its fractal nature. To address these questions we review the continuum formalism of quantum gravity with special focus on the scaling properties of the theory. We discuss several concepts of fractal dimensions which characterize the extrinsic and intrinsic geometry of quantum gravity. This work is partly based on work done in collaboration with Jan Ambjørn, Dimitrij Boulatov, Jakob L. Nielsen and Yoshiyuki Watabiki (1997). The other goal is the discussion of the discretization of quantum gravity and to address the so called quantum failure of Regge calculus. We review dynamical triangulations and show that it agrees with the continuum theory in two dimensions. Then we discuss Regge calculus and prove that a continuum limit cannot be taken in a sensible way and that it does not reproduce continuum results. This work is partly based on work done in collaboration with Jan Ambjørn, Jakob L. Nielsen and George Savvidy (1997).
Three dimensional magnetic abacus memory
Zhang, ShiLei; Zhang, JingYan; Baker, Alexander A.; Wang, ShouGuo; Yu, GuangHua; Hesjedal, Thorsten
2014-01-01
Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme. It is inspired by the idea of second quantisation, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered ‘quantised' Hall voltage, each representing a count of the spin-up and spin-down layers in the stack. This new memory system further allows for both flexible scaling of the system and fast communication among cells. The magnetic abacus provides a promising approach for future nonvolatile 3D magnetic random access memory. PMID:25146338
The Addictive Dimensionality of Obesity
Volkow, Nora D.; Wang, Gene-Jack; Tomasi, Dardo; Baler, Ruben D.
2016-01-01
Our brains are hardwired to respond and seek immediate rewards. Thus, it is not surprising that many people overeat, which in some can result in obesity, whereas others take drugs, which in some can result in addiction. Though food intake and body weight are under homeostatic regulation, when highly palatable food is available, the ability to resist the urge to eat hinges on self-control. There is no homeostatic regulator to check the intake of drugs (including alcohol); thus, regulation of drug consumption is mostly driven by self-control or unwanted effects (i.e., sedation for alcohol). Disruption in both the neurobiological processes that underlie sensitivity to reward and those that underlie inhibitory control can lead to compulsive food intake in some individuals and compulsive drug intake in others. There is increasing evidence that disruption of energy homeostasis can affect the reward circuitry and that overconsumption of rewarding food can lead to changes in the reward circuitry that result in compulsive food intake akin to the phenotype seen with addiction. Addiction research has produced new evidence that hints at significant commonalities between the neural substrates underlying the disease of addiction and at least some forms of obesity. This recognition has spurred a healthy debate to try and ascertain the extent to which these complex and dimensional disorders overlap and whether or not a deeper understanding of the crosstalk between the homeostatic and reward systems will usher in unique opportunities for prevention and treatment of both obesity and drug addiction. PMID:23374642
Schiek, Richard
2006-06-20
A method of generating two-dimensional masks from a three-dimensional model comprises providing a three-dimensional model representing a micro-electro-mechanical structure for manufacture and a description of process mask requirements, reducing the three-dimensional model to a topological description of unique cross sections, and selecting candidate masks from the unique cross sections and the cross section topology. The method further can comprise reconciling the candidate masks based on the process mask requirements description to produce two-dimensional process masks.
Calidad del aire interior en las escuelas
EPA ha desarrollado el Programa de Herramientas de Calidad del Aire Interior para las Escuelas para reducir la exposición a los contaminantes ambientales en las mismas a través de la adopción voluntaria de las prácticas para manejar la calidad del aire int
The eleven-dimensional uplift of four-dimensional supersymmetric RG flow
NASA Astrophysics Data System (ADS)
Ahn, Changhyun
2012-06-01
The squashed and stretched 7-dimensional internal metric preserving U(1)×U(1)×U(1)R symmetry possesses an Einstein-Kahler 2-fold which is a base manifold of 5-dimensional Sasaki-Einstein L space. The r(transverse to the domain wall)-dependence of the two 4-dimensional supergravity fields, that play the role of geometric parameters for squashing and stretching, makes the 11-dimensional Einstein-Maxwell equations consistent not only at the two critical points but also along the whole N=2 supersymmetric RG flow connecting them. The Ricci tensor of the solution has a common feature with the previous three 11-dimensional solutions. The 4-forms preserve only U(1)R symmetry for other generic parameters of the metric. We find an exact solution to the 11-dimensional Einstein-Maxwell equations corresponding to the lift of the 4-dimensional supersymmetric RG flow.
Dimensionality-Dependent Generalization Bounds for k-Dimensional Coding Schemes.
Liu, Tongliang; Tao, Dacheng; Xu, Dong
2016-10-01
The k-dimensional coding schemes refer to a collection of methods that attempt to represent data using a set of representative k-dimensional vectors and include nonnegative matrix factorization, dictionary learning, sparse coding, k-means clustering, and vector quantization as special cases. Previous generalization bounds for the reconstruction error of the k-dimensional coding schemes are mainly dimensionality-independent. A major advantage of these bounds is that they can be used to analyze the generalization error when data are mapped into an infinite- or high-dimensional feature space. However, many applications use finite-dimensional data features. Can we obtain dimensionality-dependent generalization bounds for k-dimensional coding schemes that are tighter than dimensionality-independent bounds when data are in a finite-dimensional feature space? Yes. In this letter, we address this problem and derive a dimensionality-dependent generalization bound for k-dimensional coding schemes by bounding the covering number of the loss function class induced by the reconstruction error. The bound is of order [Formula: see text], where m is the dimension of features, k is the number of the columns in the linear implementation of coding schemes, and n is the size of sample, [Formula: see text] when n is finite and [Formula: see text] when n is infinite. We show that our bound can be tighter than previous results because it avoids inducing the worst-case upper bound on k of the loss function. The proposed generalization bound is also applied to some specific coding schemes to demonstrate that the dimensionality-dependent bound is an indispensable complement to the dimensionality-independent generalization bounds.
Progress in multi-dimensional upwind differencing
NASA Technical Reports Server (NTRS)
Vanleer, Bram
1992-01-01
Multi-dimensional upwind-differencing schemes for the Euler equations are reviewed. On the basis of the first-order upwind scheme for a one-dimensional convection equation, the two approaches to upwind differencing are discussed: the fluctuation approach and the finite-volume approach. The usual extension of the finite-volume method to the multi-dimensional Euler equations is not entirely satisfactory, because the direction of wave propagation is always assumed to be normal to the cell faces. This leads to smearing of shock and shear waves when these are not grid-aligned. Multi-directional methods, in which upwind-biased fluxes are computed in a frame aligned with a dominant wave, overcome this problem, but at the expense of robustness. The same is true for the schemes incorporating a multi-dimensional wave model not based on multi-dimensional data but on an 'educated guess' of what they could be. The fluctuation approach offers the best possibilities for the development of genuinely multi-dimensional upwind schemes. Three building blocks are needed for such schemes: a wave model, a way to achieve conservation, and a compact convection scheme. Recent advances in each of these components are discussed; putting them all together is the present focus of a worldwide research effort. Some numerical results are presented, illustrating the potential of the new multi-dimensional schemes.
Three-dimensional head anthropometric analysis
NASA Astrophysics Data System (ADS)
Enciso, Reyes; Shaw, Alex M.; Neumann, Ulrich; Mah, James
2003-05-01
Currently, two-dimensional photographs are most commonly used to facilitate visualization, assessment and treatment of facial abnormalities in craniofacial care but are subject to errors because of perspective, projection, lack metric and 3-dimensional information. One can find in the literature a variety of methods to generate 3-dimensional facial images such as laser scans, stereo-photogrammetry, infrared imaging and even CT however each of these methods contain inherent limitations and as such no systems are in common clinical use. In this paper we will focus on development of indirect 3-dimensional landmark location and measurement of facial soft-tissue with light-based techniques. In this paper we will statistically evaluate and validate a current three-dimensional image-based face modeling technique using a plaster head model. We will also develop computer graphics tools for indirect anthropometric measurements in a three-dimensional head model (or polygonal mesh) including linear distances currently used in anthropometry. The measurements will be tested against a validated 3-dimensional digitizer (MicroScribe 3DX).
Four-Dimensional Graded Consciousness
Jonkisz, Jakub; Wierzchoń, Michał; Binder, Marek
2017-01-01
Both the multidimensional phenomenon and the polysemous notion of consciousness continue to prove resistant to consistent measurement and unambiguous definition. This is hardly surprising, given that there is no agreement even as regards the most fundamental issues they involve. One of the basic disagreements present in the continuing debate about consciousness pertains to its gradational nature. The general aim of this article is to show how consciousness might be graded and multidimensional at the same time. We therefore focus on the question of what it is, exactly, that is or could be graded in cases of consciousness, and how we can measure it. Ultimately, four different gradable aspects of consciousness will be described: quality, abstractness, complexity and usefulness, which belong to four different dimensions, these being understood, respectively, as phenomenal, semantic, physiological, and functional. Consequently, consciousness may be said to vary with respect to phenomenal quality, semantic abstraction, physiological complexity, and functional usefulness. It is hoped that such a four-dimensional approach will help to clarify and justify claims about the hierarchical nature of consciousness. The approach also proves explanatorily advantageous, as it enables us not only to draw attention to certain new and important differences in respect of subjective measures of awareness and to justify how a given creature may be ranked higher in one dimension of consciousness and lower in terms of another, but also allows for innovative explanations of a variety of well-known phenomena (amongst these, the interpretations of blindsight and locked-in syndrome will be briefly outlined here). Moreover, a 4D framework makes possible many predictions and hypotheses that may be experimentally tested (We point out a few such possibilities pertaining to interdimensional dependencies). PMID:28377738
Four-Dimensional Graded Consciousness.
Jonkisz, Jakub; Wierzchoń, Michał; Binder, Marek
2017-01-01
Both the multidimensional phenomenon and the polysemous notion of consciousness continue to prove resistant to consistent measurement and unambiguous definition. This is hardly surprising, given that there is no agreement even as regards the most fundamental issues they involve. One of the basic disagreements present in the continuing debate about consciousness pertains to its gradational nature. The general aim of this article is to show how consciousness might be graded and multidimensional at the same time. We therefore focus on the question of what it is, exactly, that is or could be graded in cases of consciousness, and how we can measure it. Ultimately, four different gradable aspects of consciousness will be described: quality, abstractness, complexity and usefulness, which belong to four different dimensions, these being understood, respectively, as phenomenal, semantic, physiological, and functional. Consequently, consciousness may be said to vary with respect to phenomenal quality, semantic abstraction, physiological complexity, and functional usefulness. It is hoped that such a four-dimensional approach will help to clarify and justify claims about the hierarchical nature of consciousness. The approach also proves explanatorily advantageous, as it enables us not only to draw attention to certain new and important differences in respect of subjective measures of awareness and to justify how a given creature may be ranked higher in one dimension of consciousness and lower in terms of another, but also allows for innovative explanations of a variety of well-known phenomena (amongst these, the interpretations of blindsight and locked-in syndrome will be briefly outlined here). Moreover, a 4D framework makes possible many predictions and hypotheses that may be experimentally tested (We point out a few such possibilities pertaining to interdimensional dependencies).
Three-dimensional co-culture process
NASA Technical Reports Server (NTRS)
Wolf, David A. (Inventor); Goodwin, Thomas J. (Inventor)
1992-01-01
The present invention relates to a 3-dimensional co-culture process, more particularly to methods or co-culturing at least two types of cells in a culture environment, either in space or in unit gravity, with minimum shear stress, freedom for 3-dimensional spatial orientation of the suspended particles and localization of particles with differing or similar sedimentation properties in a similar spatial region to form 3-dimensional tissue-like structures. Several examples of multicellular 3-dimensional experiences are included. The protocol and procedure are also set forth. The process allows simultaneous culture of multiple cell types and supporting substrates in a manner which does not disrupt the 3-dimensional spatial orientation of these components. The co-cultured cells cause a mutual induction effect which mimics the natural hormonal signals and cell interactions found in the intact organism. This causes the tissues to differentiate and form higher 3-dimensional structures such as glands, junctional complexes polypoid geometries, and microvilli which represent the corresponding in-vitro structures to a greater degree than when the cell types are cultured individually or by conventional processes. This process was clearly demonstrated for the case of two epithelial derived colon cancer lines, each co-cultured with normal human fibroblasts and with microcarrier bead substrates. The results clearly demonstrate increased 3-dimensional tissue-like structure and biochemical evidence of an increased differentiation state. With the present invention a variety of cells may be co-cultured to produce tissue which has 3-dimensionality and has some of the characteristics of in-vitro tissue. The process provides enhanced 3-dimensional tissue which create a multicellular organoid differentiation model.
Quantifying Photonic High-Dimensional Entanglement
NASA Astrophysics Data System (ADS)
Martin, Anthony; Guerreiro, Thiago; Tiranov, Alexey; Designolle, Sébastien; Fröwis, Florian; Brunner, Nicolas; Huber, Marcus; Gisin, Nicolas
2017-03-01
High-dimensional entanglement offers promising perspectives in quantum information science. In practice, however, the main challenge is to devise efficient methods to characterize high-dimensional entanglement, based on the available experimental data which is usually rather limited. Here we report the characterization and certification of high-dimensional entanglement in photon pairs, encoded in temporal modes. Building upon recently developed theoretical methods, we certify an entanglement of formation of 2.09(7) ebits in a time-bin implementation, and 4.1(1) ebits in an energy-time implementation. These results are based on very limited sets of local measurements, which illustrates the practical relevance of these methods.
Lyapunov exponents for infinite dimensional dynamical systems
NASA Technical Reports Server (NTRS)
Mhuiris, Nessan Mac Giolla
1987-01-01
Classically it was held that solutions to deterministic partial differential equations (i.e., ones with smooth coefficients and boundary data) could become random only through one mechanism, namely by the activation of more and more of the infinite number of degrees of freedom that are available to such a system. It is only recently that researchers have come to suspect that many infinite dimensional nonlinear systems may in fact possess finite dimensional chaotic attractors. Lyapunov exponents provide a tool for probing the nature of these attractors. This paper examines how these exponents might be measured for infinite dimensional systems.
On dimensional reduction of magical supergravity theories
NASA Astrophysics Data System (ADS)
Kan, Naoto; Mizoguchi, Shun'ya
2016-11-01
We prove, by a direct dimensional reduction and an explicit construction of the group manifold, that the nonlinear sigma model of the dimensionally reduced three-dimensional A = R magical supergravity is F 4 (+ 4) / (USp (6) × SU (2)). This serves as a basis for the solution generating technique in this supergravity as well as allows to give the Lie algebraic characterizations to some of the parameters and functions in the original D = 5 Lagrangian. Generalizations to other magical supergravities are also discussed.
Three-dimensional laser window formation
NASA Technical Reports Server (NTRS)
Verhoff, Vincent G.
1992-01-01
The NASA Lewis Research Center has developed and implemented a unique process for forming flawless three-dimensional laser windows. These windows represent a major part of specialized, nonintrusive laser data acquisition systems used in a variety of compressor and turbine research test facilities. This report discusses in detail the aspects of three-dimensional laser window formation. It focuses on the unique methodology and the peculiarities associated with the formation of these windows. Included in this discussion are the design criteria, bonding mediums, and evaluation testing for three-dimensional laser windows.
Three-dimensional stochastic vortex flows
NASA Astrophysics Data System (ADS)
Esposito, R.; Pulvirenti, M.
1989-08-01
It is well known that the dynamics of point vortices approximate, under suitable limits, the two-dimensional Euler flow for an ideal fluid. To find particle models for three-dimensional flows is a more intricate problem. A stochastic version of the algorithm introduced by Beale amd Maida (1982) for simulating the behavior of a three-dimensional Euler flow is introduced here, and convergence to the Navier-Stokes (NS) flow in R exp 3 is shown. The result is based on a stochastic Lagrangian picture of the NS equations.
Low-dimensional chaos in turbulence
NASA Technical Reports Server (NTRS)
Vastano, John A.
1989-01-01
Direct numerical simulations are being performed on two different fluid flows in an attempt to discover the mechanism underlying the transition to turbulence in each. The first system is Taylor-Couette flow; the second, two-dimensional flow over an airfoil. Both flows exhibit a gradual transition to high-dimensional turbulence through low-dimensional chaos. The hope is that the instabilities leading to chaos will be easier to relate to physical processes in this case, and that the understanding of these mechanisms can then be applied to a wider array of turbulent systems.
Two Dimensional Mechanism for Insect Hovering
Jane Wang, Z.
2000-09-04
Resolved computation of two dimensional insect hovering shows for the first time that a two dimensional hovering motion can generate enough lift to support a typical insect weight. The computation reveals a two dimensional mechanism of creating a downward dipole jet of counterrotating vortices, which are formed from leading and trailing edge vortices. The vortex dynamics further elucidates the role of the phase relation between the wing translation and rotation in lift generation and explains why the instantaneous forces can reach a periodic state after only a few strokes. The model predicts the lower limits in Reynolds number and amplitude above which the averaged forces are sufficient. (c) 2000 The American Physical Society.
Three-dimensional velocity measurements using LDA
NASA Astrophysics Data System (ADS)
Buchhave, Preben
The design requirements for and development of an LDA that measures the three components of the fluid velocity vector are described. The problems encountered in LDA measurements in highly turbulent flows, multivariate response, velocity bias, spatial resolution, temporal resolution, and dynamic range, are discussed. The use of the fringe and/or the reference beam methods to measure the three velocity components, and the use of color, frequency shift, and polarization to separate three velocity projections are examined. Consideration is given to the coordinate transformation, the presentation of three-dimensional LDA data, and the possibility of three-dimensional bias correction. Procedures for conducting three-dimensional LDA measurements are proposed.
Three-dimensional patterning methods and related devices
Putnam, Morgan C.; Kelzenberg, Michael D.; Atwater, Harry A.; Boettcher, Shannon W.; Lewis, Nathan S.; Spurgeon, Joshua M.; Turner-Evans, Daniel B.; Warren, Emily L.
2016-12-27
Three-dimensional patterning methods of a three-dimensional microstructure, such as a semiconductor wire array, are described, in conjunction with etching and/or deposition steps to pattern the three-dimensional microstructure.
Three Dimensional Optic Tissue Culture and Process
NASA Technical Reports Server (NTRS)
OConnor, Kim C. (Inventor); Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); Aten, Laurie A. (Inventor); Francis, Karen M. (Inventor); Caldwell, Delmar R. (Inventor); Prewett, Tacey L. (Inventor); Fitzgerald, Wendy S. (Inventor)
1999-01-01
A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioireactor at low shear conditions. The tissue forms as normal, functional tissue grows with tissue organization and extracellular matrix formation.
Two-dimensional function photonic crystals
NASA Astrophysics Data System (ADS)
Liu, Xiao-Jing; Liang, Yu; Ma, Ji; Zhang, Si-Qi; Li, Hong; Wu, Xiang-Yao; Wu, Yi-Heng
2017-01-01
In this paper, we have studied two-dimensional function photonic crystals, in which the dielectric constants of medium columns are the functions of space coordinates , that can become true easily by electro-optical effect and optical kerr effect. We calculated the band gap structures of TE and TM waves, and found the TE (TM) wave band gaps of function photonic crystals are wider (narrower) than the conventional photonic crystals. For the two-dimensional function photonic crystals, when the dielectric constant functions change, the band gaps numbers, width and position should be changed, and the band gap structures of two-dimensional function photonic crystals can be adjusted flexibly, the needed band gap structures can be designed by the two-dimensional function photonic crystals, and it can be of help to design optical devices.
Two-dimensional generalized Toda lattice
NASA Astrophysics Data System (ADS)
Mikhailov, A. V.; Olshanetsky, M. A.; Perelomov, A. M.
1981-12-01
The zero curvature representation is obtained for the two-dimensional generalized Toda lattices connected with semisimple Lie algebras. The reduction group and conservation laws are found and the mass spectrum is calculated.
Second virial coefficient of one dimensional gas
Mijatovic, M.
1982-08-01
The second virial coefficient of a one dimensional gas is calculated using the expressions for the scattering amplitude. The scattering amplitude is chosen in the form of rational function of wave vector.
One-Dimensional Czedli-Type Islands
ERIC Educational Resources Information Center
Horvath, Eszter K.; Mader, Attila; Tepavcevic, Andreja
2011-01-01
The notion of an island has surfaced in recent algebra and coding theory research. Discrete versions provide interesting combinatorial problems. This paper presents the one-dimensional case with finitely many heights, a topic convenient for student research.
One-Dimensional Czedli-Type Islands
ERIC Educational Resources Information Center
Horvath, Eszter K.; Mader, Attila; Tepavcevic, Andreja
2011-01-01
The notion of an island has surfaced in recent algebra and coding theory research. Discrete versions provide interesting combinatorial problems. This paper presents the one-dimensional case with finitely many heights, a topic convenient for student research.
Three-dimensional tori and Arnold tongues.
Sekikawa, Munehisa; Inaba, Naohiko; Kamiyama, Kyohei; Aihara, Kazuyuki
2014-03-01
This study analyzes an Arnold resonance web, which includes complicated quasi-periodic bifurcations, by conducting a Lyapunov analysis for a coupled delayed logistic map. The map can exhibit a two-dimensional invariant torus (IT), which corresponds to a three-dimensional torus in vector fields. Numerous one-dimensional invariant closed curves (ICCs), which correspond to two-dimensional tori in vector fields, exist in a very complicated but reasonable manner inside an IT-generating region. Periodic solutions emerge at the intersections of two different thin ICC-generating regions, which we call ICC-Arnold tongues, because all three independent-frequency components of the IT become rational at the intersections. Additionally, we observe a significant bifurcation structure where conventional Arnold tongues transit to ICC-Arnold tongues through a Neimark-Sacker bifurcation in the neighborhood of a quasi-periodic Hopf bifurcation (or a quasi-periodic Neimark-Sacker bifurcation) boundary.
High-Dimensional Profiling for Computational Diagnosis.
Lottaz, Claudio; Gronwald, Wolfram; Spang, Rainer; Engelmann, Julia C
2017-01-01
New technologies allow for high-dimensional profiling of patients. For instance, genome-wide gene expression analysis in tumors or in blood is feasible with microarrays, if all transcripts are known, or even without this restriction using high-throughput RNA sequencing. Other technologies like NMR finger printing allow for high-dimensional profiling of metabolites in blood or urine. Such technologies for high-dimensional patient profiling represent novel possibilities for molecular diagnostics. In clinical profiling studies, researchers aim to predict disease type, survival, or treatment response for new patients using high-dimensional profiles. In this process, they encounter a series of obstacles and pitfalls. We review fundamental issues from machine learning and recommend a procedure for the computational aspects of a clinical profiling study.
Three dimensional optic tissue culture and process
NASA Technical Reports Server (NTRS)
Spaulding, Glenn F. (Inventor); Prewett, Tacey L. (Inventor); Goodwin, Thomas J. (Inventor); Francis, Karen M. (Inventor); Cardwell, Delmar R. (Inventor); Oconnor, Kim (Inventor); Fitzgerald, Wendy S. (Inventor); Aten, Laurie A. (Inventor)
1994-01-01
A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioreactor at low shear conditions. The tissue forms normal, functional tissue organization and extracellular matrix.
Two-dimensional plasmonic nanosurface for photovoltaics
NASA Astrophysics Data System (ADS)
Polemi, Alessia; Shuford, Kevin L.
2011-12-01
In this paper, we investigate a two-dimensional corrugated plasmonic nanosurface for efficient light trapping in a photovoltaic cell. Inspired by a well-known one-dimensional grating nanosurface, the present configuration is composed of two perpendicular gratings in the metal film that intersect to yield cross-shaped nanoelements. The surface corrugation is then covered by a silicon film. An additional degree of freedom can be introduced into the design by interrupting the grid in both directions. We show that this extra spacing between the array elements can be used to tune the absorption properties of the nanosurface. By including the effect of the solar spectrum, we demonstrate how this two-dimensional configuration is more efficient than its one-dimensional counterpart in terms of the actual short circuit photocurrent density. Finally, we propose possible extensions of this structure design, which can further enhance the solar cell performance.
Device fabrication: Three-dimensional printed electronics
NASA Astrophysics Data System (ADS)
Lewis, Jennifer A.; Ahn, Bok Y.
2015-02-01
Can three-dimensional printing enable the mass customization of electronic devices? A study that exploits this method to create light-emitting diodes based on 'quantum dots' provides a step towards this goal.
Bayesian Methods for High Dimensional Linear Models
Mallick, Himel; Yi, Nengjun
2013-01-01
In this article, we present a selective overview of some recent developments in Bayesian model and variable selection methods for high dimensional linear models. While most of the reviews in literature are based on conventional methods, we focus on recently developed methods, which have proven to be successful in dealing with high dimensional variable selection. First, we give a brief overview of the traditional model selection methods (viz. Mallow’s Cp, AIC, BIC, DIC), followed by a discussion on some recently developed methods (viz. EBIC, regularization), which have occupied the minds of many statisticians. Then, we review high dimensional Bayesian methods with a particular emphasis on Bayesian regularization methods, which have been used extensively in recent years. We conclude by briefly addressing the asymptotic behaviors of Bayesian variable selection methods for high dimensional linear models under different regularity conditions. PMID:24511433
Realisation of 3-dimensional data sets.
NASA Astrophysics Data System (ADS)
Brown, D.; Galsgaard, K.; Ireland, J.; Verwichte, E.; Walsh, R.
The visualisation of three-dimensional objects on two dimensions is a very common problem, but is a tricky one to solve. Every discipline has its way of solving it. The artist uses light-shade interaction, perspective, special colour coding. The architect produces projections of the object. The cartographer uses both colour-coding and shading to represent height elevations. There have been many attempts in the last century by the entertainment industry to produce a three-dimensional illusion, in the fifties it was fashionable to have 3d movies which utilize the anaglyph method. Nowadays one can buy "Magic Eye" postcards which show a hidden three dimensional picture if you stare at it half cross-eyed. This poster attempts to demonstrate how some of these techniques can be applied to three-dimensional data sets that can occur in solar physics.
Three-dimensional tori and Arnold tongues
Sekikawa, Munehisa; Inaba, Naohiko; Kamiyama, Kyohei; Aihara, Kazuyuki
2014-03-15
This study analyzes an Arnold resonance web, which includes complicated quasi-periodic bifurcations, by conducting a Lyapunov analysis for a coupled delayed logistic map. The map can exhibit a two-dimensional invariant torus (IT), which corresponds to a three-dimensional torus in vector fields. Numerous one-dimensional invariant closed curves (ICCs), which correspond to two-dimensional tori in vector fields, exist in a very complicated but reasonable manner inside an IT-generating region. Periodic solutions emerge at the intersections of two different thin ICC-generating regions, which we call ICC-Arnold tongues, because all three independent-frequency components of the IT become rational at the intersections. Additionally, we observe a significant bifurcation structure where conventional Arnold tongues transit to ICC-Arnold tongues through a Neimark-Sacker bifurcation in the neighborhood of a quasi-periodic Hopf bifurcation (or a quasi-periodic Neimark-Sacker bifurcation) boundary.
Dynamic Dimensionality Identification for Quantum Control
NASA Astrophysics Data System (ADS)
Roslund, Jonathan; Rabitz, Herschel
2014-04-01
The control of quantum systems with shaped laser pulses presents a paradox since the relative ease with which solutions are discovered appears incompatible with the enormous variety of pulse shapes accessible with a standard pulse shaper. Quantum landscape theory indicates that the relevant search dimensionality is not dictated by the number of pulse shaper elements, but rather is related to the number of states participating in the controlled dynamics. The actual dimensionality is encoded within the sensitivity of the observed yield to all of the pulse shaper elements. To investigate this proposition, the Hessian matrix is measured for controlled transitions amongst states of atomic rubidium, and its eigendecomposition reveals a dimensionality consistent with that predicted by landscape theory. Additionally, this methodology furnishes a low-dimensional picture that captures the essence of the light-matter interaction and the ensuing system dynamics.
Analyzing High-Dimensional Multispectral Data
NASA Technical Reports Server (NTRS)
Lee, Chulhee; Landgrebe, David A.
1993-01-01
In this paper, through a series of specific examples, we illustrate some characteristics encountered in analyzing high- dimensional multispectral data. The increased importance of the second-order statistics in analyzing high-dimensional data is illustrated, as is the shortcoming of classifiers such as the minimum distance classifier which rely on first-order variations alone. We also illustrate how inaccurate estimation or first- and second-order statistics, e.g., from use of training sets which are too small, affects the performance of a classifier. Recognizing the importance of second-order statistics on the one hand, but the increased difficulty in perceiving and comprehending information present in statistics derived from high-dimensional data on the other, we propose a method to aid visualization of high-dimensional statistics using a color coding scheme.
Dispersionless (3+1)-dimensional integrable hierarchies.
Błaszak, Maciej; Sergyeyev, Artur
2017-05-01
In this paper, we introduce a multi-dimensional version of the R-matrix approach to the construction of integrable hierarchies. Applying this method to the case of the Lie algebra of functions with respect to the contact bracket, we construct integrable hierarchies of (3+1)-dimensional dispersionless systems of the type recently introduced in Sergyeyev (2014 (http://arxiv.org/abs/1401.2122)).
Factorizations of one-dimensional classical systems
Kuru, Senguel; Negro, Javier
2008-02-15
A class of one-dimensional classical systems is characterized from an algebraic point of view. The Hamiltonians of these systems are factorized in terms of two functions that together with the Hamiltonian itself close a Poisson algebra. These two functions lead directly to two time-dependent integrals of motion from which the phase motions are derived algebraically. The systems so obtained constitute the classical analogues of the well known factorizable one-dimensional quantum mechanical systems.
Three-dimensional magnetic field annihilation
NASA Astrophysics Data System (ADS)
Jardine, M.; Allen, H. R.; Grundy, R. E.
1993-11-01
We present a family of three-dimensional nonlinear solutions for magnetic field annihilation in a current sheet, including the effects of resistivity and viscosity. The different members of the family are characterized by the imposed vorticity of the flow that brings the field lines together. Since in a three- dimensional flow the vorticity can be increased by the stretching of vortex lines (an effect that is absent in two dimensions), we find some striking differences to our previous two-dimensional analysis. In both the two-dimensional and three-dimensional analyses, above a certain critical imposed vorticity omegacrit, the flow breaks up into cells with current sheet is completely altered. In the two-dimensional analysis, omegacrit is a steeply increasing function of the viscous Reynolds number R, whereas in the three-dimensional case, it quickly asymptotes to only omegacrit = 2v0/L where v0 and L are the characteristic velocity and length scale of the flow, respectively. The width of the current sheet, which depends on the speed at which field lines are carried into it, also responds differently to an increase in R. In two dimensions, the current sheet narrows for all vorticities, but three dimensions, it narrows when the imposed vorticity is negative and widens when it is positive. Also we find that the current density within the current sheet varies as the nature of the flow is changed, rather than being constant as in the the two-dimensional case. Finally, we find that there is a minimum value of the plasma beta betamin below which the plasma pressure is negative. For the nonsheared (neutral current sheet) case, betamin increases rapidly with the magnetic Reynolds number Rm such that this type of annihilation is only possible for a high-beta plasma. For a sheared magnetic field, however, betamin is much lower, making this type of annihilation more relevant to the sonar corona.
(2+1)-dimensional supersymmetric integrable equations
NASA Astrophysics Data System (ADS)
Yan, Zhao-Wen; Tala; Chen, Fang; Liu, Tao-Ran; Han, Jing-Min
2017-09-01
By means of two different approaches, we construct the (2+1)-dimensional supersymmetric integrable equations based on the super Lie algebra osp(3/2). We relax the constraint condition of homogenous space of super Lie algebra osp(3/2) in the first approach. In another one, the technique of extending the dimension of the systems is used. Furthermore for the (2 + 1)-dimensional supersymmetric integrable equations, we also derive their Bäcklund transformations.
Three-dimensional accelerating electromagnetic waves.
Bandres, Miguel A; Alonso, Miguel A; Kaminer, Ido; Segev, Mordechai
2013-06-17
We present a general theory of three-dimensional non-paraxial spatially-accelerating waves of the Maxwell equations. These waves constitute a two-dimensional structure exhibiting shape-invariant propagation along semicircular trajectories. We provide classification and characterization of possible shapes of such beams, expressed through the angular spectra of parabolic, oblate and prolate spheroidal fields. Our results facilitate the design of accelerating beams with novel structures, broadening scope and potential applications of accelerating beams.
One dimensional representations in quantum optics
NASA Technical Reports Server (NTRS)
Janszky, J.; Adam, P.; Foldesi, I.; Vinogradov, An. V.
1993-01-01
The possibility of representing the quantum states of a harmonic oscillator not on the whole alpha-plane but on its one dimensional manifolds is considered. It is shown that a simple Gaussian distribution along a straight line describes a quadrature squeezed state while a similar Gaussian distribution along a circle leads to the amplitude squeezed state. The connection between the one dimensional representations and the usual Glauber representation is discussed.
Three-dimensional motor schema based navigation
NASA Technical Reports Server (NTRS)
Arkin, Ronald C.
1989-01-01
Reactive schema-based navigation is possible in space domains by extending the methods developed for ground-based navigation found within the Autonomous Robot Architecture (AuRA). Reformulation of two dimensional motor schemas for three dimensional applications is a straightforward process. The manifold advantages of schema-based control persist, including modular development, amenability to distributed processing, and responsiveness to environmental sensing. Simulation results show the feasibility of this methodology for space docking operations in a cluttered work area.
Finite-dimensional collisionless kinetic theory
NASA Astrophysics Data System (ADS)
Burby, J. W.
2017-03-01
A collisionless kinetic plasma model may often be cast as an infinite-dimensional noncanonical Hamiltonian system. I show that, when this is the case, the model can be discretized in space and particles while preserving its Hamiltonian structure, thereby producing a finite-dimensional Hamiltonian system that approximates the original kinetic model. I apply the general theory to two example systems: the relativistic Vlasov-Maxwell system with spin and a gyrokinetic Vlasov-Maxwell system.
Fully localized two-dimensional embedded solitons
Yang Jianke
2010-11-15
We report the prediction of fully localized two-dimensional embedded solitons. These solitons are obtained in a quasi-one-dimensional waveguide array which is periodic along one spatial direction and localized along the orthogonal direction. Under appropriate nonlinearity, these solitons are found to exist inside the Bloch bands (continuous spectrum) of the waveguide and thus are embedded solitons. These embedded solitons are fully localized along both spatial directions. In addition, they are fully stable under perturbations.
Developments in two-dimensional regenerator modeling
NASA Astrophysics Data System (ADS)
Gedeon, David
The development status of the manifold-estimate, or 'MANIFEST', computer code for two-dimensional modeling of Stirling cycle engines' regenerator-element flow. MANIFEST can model oscillating compressible fluid internal flows in arbitrarily shaped two-dimensional regions, irrespective of whether these are filled with porous materials or empty. An interactive examination of the solution output can be conducted graphically, for ease of boundary condition specification and viewing of flow velocity, temperature, and pressure plots at various locations.
Two-dimensional order and disorder thermofields
Belvedere, L. V.
2006-11-15
The main objective of this paper was to obtain the two-dimensional order and disorder thermal operators using the Thermofield Bosonization formalism. We show that the general property of the two-dimensional world according with the bosonized Fermi field at zero temperature can be constructed as a product of an order and a disorder variables which satisfy a dual field algebra holds at finite temperature. The general correlation functions of the order and disorder thermofields are obtained.
Interpolation by two-dimensional cubic convolution
NASA Astrophysics Data System (ADS)
Shi, Jiazheng; Reichenbach, Stephen E.
2003-08-01
This paper presents results of image interpolation with an improved method for two-dimensional cubic convolution. Convolution with a piecewise cubic is one of the most popular methods for image reconstruction, but the traditional approach uses a separable two-dimensional convolution kernel that is based on a one-dimensional derivation. The traditional, separable method is sub-optimal for the usual case of non-separable images. The improved method in this paper implements the most general non-separable, two-dimensional, piecewise-cubic interpolator with constraints for symmetry, continuity, and smoothness. The improved method of two-dimensional cubic convolution has three parameters that can be tuned to yield maximal fidelity for specific scene ensembles characterized by autocorrelation or power-spectrum. This paper illustrates examples for several scene models (a circular disk of parametric size, a square pulse with parametric rotation, and a Markov random field with parametric spatial detail) and actual images -- presenting the optimal parameters and the resulting fidelity for each model. In these examples, improved two-dimensional cubic convolution is superior to several other popular small-kernel interpolation methods.
Three-dimensional printing of surgical anatomy.
Powers, Mary K; Lee, Benjamin R; Silberstein, Jonathan
2016-05-01
Over the past decade, three-dimensional printing for the medical field has been expanding rapidly throughout all of medicine. This manuscript reviews the current and potential applications for three-dimensional printing, including education, presurgical planning, surgical simulation, bioprinting, and printed surgical equipment. Three-dimensional printing has proved most relevant in the fields of craniofacial, plastic, orthopedics, and especially, urologic surgery. This review focuses on several examples of how three-dimensional printing can be utilized, with emphasis on renal models for renal cell carcinoma, ureteral stents, and staghorn calculus. From an education standpoint, both patients and residents can benefit from the use of three-dimensional printed models, and even skilled surgeons report better understanding of complex procedures by using printed models. Three-dimensional printing in the field of medicine is growing quickly, and will soon be incorporated into the way residents are taught and patients are educated. For surgical simulation in a variety of disease processes, this will be particularly useful for urologic surgery.
Central subspace dimensionality reduction using covariance operators.
Kim, Minyoung; Pavlovic, Vladimir
2011-04-01
We consider the task of dimensionality reduction informed by real-valued multivariate labels. The problem is often treated as Dimensionality Reduction for Regression (DRR), whose goal is to find a low-dimensional representation, the central subspace, of the input data that preserves the statistical correlation with the targets. A class of DRR methods exploits the notion of inverse regression (IR) to discover central subspaces. Whereas most existing IR techniques rely on explicit output space slicing, we propose a novel method called the Covariance Operator Inverse Regression (COIR) that generalizes IR to nonlinear input/output spaces without explicit target slicing. COIR's unique properties make DRR applicable to problem domains with high-dimensional output data corrupted by potentially significant amounts of noise. Unlike recent kernel dimensionality reduction methods that employ iterative nonconvex optimization, COIR yields a closed-form solution. We also establish the link between COIR, other DRR techniques, and popular supervised dimensionality reduction methods, including canonical correlation analysis and linear discriminant analysis. We then extend COIR to semi-supervised settings where many of the input points lack their labels. We demonstrate the benefits of COIR on several important regression problems in both fully supervised and semi-supervised settings.
Three-Dimensional Field Theories from Infinite-Dimensional Lie Algebras
NASA Astrophysics Data System (ADS)
Perret, R. E. C.
A procedure for constructing topological actions from centrally extended Lie algebras is introduced. For a Kac-Moody algebra, this produces the three-dimensional Chern-Simons theory, while for the Virasoro algebra, the result is a new three-dimensional topological field theory whose physical states satisfy the Virasoro Ward identity. This topological field theory is shown to be a first order formulation of two-dimensional induced gravity in the chiral gauge. The extension to W3 gravity is discussed.
Transition from a Two-Dimensional Superfluid to a One-Dimensional Mott Insulator
Bergkvist, Sara; Rosengren, Anders; Saers, Robert; Lundh, Emil; Rehn, Magnus; Kastberg, Anders
2007-09-14
A two-dimensional system of atoms in an anisotropic optical lattice is studied theoretically. If the system is finite in one direction, it is shown to exhibit a transition between a two-dimensional superfluid and a one-dimensional Mott insulating chain of superfluid tubes. Monte Carlo simulations are consistent with the expectation that the phase transition is of Kosterlitz-Thouless type. The effect of the transition on experimental time-of-flight images is discussed.
Produccion Gaseosa del Cometa Halley: Erupciones Y Fotodisociacion del Radical OH
NASA Astrophysics Data System (ADS)
Silva, A. M.; Mirabel, I. F.
1990-11-01
RESUMEN:En este trabajo informamos la detecci6n de 20 erupciones en la li'nea de =18cm (1667MHz) del radical OH en el Cometa Halley.Las observaciones incluyen todos los monitoreos existentes y se extienden desde 120 dias antes del perihelio hasta 90 dias despues.Se detectan bruscos crecimientos en el flujo medido,hasta un factor 1O,seguidos por decaimientos lentos asociados con la fotodisociaci6n del OH. Se obtuvieron valores para el tiempo de vida fotoquimico del OH y del H2O basandose en el modelo desarrollado previamente por Silva(1988). Esos tiempos de vida estan de acuerdo con predicciones teoricas y con las observaciones en el Ultravioleta, y los resultados, los que son fuertemente dependientes de la velocidad heliocentrica del Coineta (variando hasta un factor 6), han sido calculados para varios rangos de velocidad entre +28 y -28 km/seg. Key wo'L :
NASA Astrophysics Data System (ADS)
Hashim, Mohammad Firdaus Abu; Ramakrishnan, Sivakumar; Mohamad, Ahmad Azmin
2014-06-01
Due to low environmental impact and rechargeable capability, the Nickel Metal Hydride battery has been considered to be one of the most promising candidate battery for electrical vehicle nowadays. The energy delivered by the Nickel Metal Hydride battery depends heavily on its discharge profile and generally it is intangible to tract the trend of the energydissipation that is stored in the battery for informative analysis. The thermal models were developed in 1-dimensional and 2-dimensional using Matlab and these models are capable of predicting the temperature distributions inside a cell. The simulated results were validated and verified with referred exact sources of experimental data using Minitab software. The result for 1-Dimensional showed that the correlations between experimental and predicted results for the time intervals 60 minutes, 90 minutes, and 114 minutes frompositive to negative electrode thermal dissipationdirection are34%, 83%, and 94% accordingly while for the 2-Dimensional the correlational results for the same above time intervals are44%, 93% and 95%. These correlationalresults between experimental and predicted clearly indicating the thermal behavior under natural convention can be well fitted after around 90 minutes durational time and 2-Dimensional model can predict the results more accurately compared to 1-Dimensional model. Based on the results obtained from simulations, it can be concluded that both 1-Dimensional and 2-Dimensional models can predict nearly similar thermal behavior under natural convention while 2-Dimensional model was used to predict thermal behavior under forced convention for better accuracy.
[Two-dimensional and three-dimensional CT diagnosis of alimentary tract].
Shiraga, N
2001-10-01
The recent development of multidetector-row CT(MDCT) has made it possible to obtain three-dimensional images of the alimentary tract that offer new diagnostic potential. In its two-dimensional diagnosis of the alimentary tract, MDCT has also changed the concept of the oral contrast agent. Before MDCT, we routinely used a positive contrast agent to distinguish the stomach and intestine from other organs and masses. The excellent slice profile acquired by MDCT can distinguish the alimentary tract and depict abnormal findings without the use of a positive contrast agent. With the use of an intravenous contrast medium, the alimentary tract itself, alimentary tumors, and inflammatory disease are well demarcated with water and air. Moreover, the combination of two-dimensional and three-dimensional diagnostic images makes it possible to detect and assess early gastric and colonic cancers as conventional gastroscopy and colonoscopy. Although the lack of texture information is one of the disadvantages of three-dimensional CT, three-dimensional CT diagnosis of the alimentary tract is less invasive and more objective than conventional studies. Advances in three-dimensional imaging with isotropic data sets will lead to the use of two-dimensional and three-dimensional CT diagnosis as one of the standard examinations of the alimentary tract.
Three-dimensional map construction.
Jenks, G F; Brown, D A
1966-11-18
Three-dimensional maps are useful tools which have been neglected for some time. They shouldbe more commonly used, and familiarity with the techniques discussed in this article should dispel any qualms anyone might ve about needing artistic talent to nstruct them. The saving in time esulting from the use of an anamorphoser provides a further incentive. The anamorphoser transformations discussed above were all prepared by using straight slits, oriented at right angles to each other and placed so that all planes of the elements were parallel to each other. It is possible to vary these conditions in an infinite number of ways and thereby produce nonparallel tranceformations. Some of these variations are illustrated in Fig. 10. All the illustrations in Fig. 10 are transformations of the planimetric weather map shown in Fig. 8A. The variations used for the maps of Fig. 10 are as follows. (A) All planes parallel, with a curved rear slit; (B) all planes parallel, with curved slits front and rear; ( C) all planes parallel, with S-shaped rear slit; (D) all planes parallel, with an undulating rear slit; (E) all planes parallel, with curved front and undulating rear slit; (F) plane of the original rotated on the horizontal axis-both slits curved; (G) plane of the original rotated on thevertical axis- both slits curved; (H) plane of the original rotated on the horizontal axis -both slits straight. These are only a few of the many transformations which can be made with an anamorphoser, butthey do point toward some interesting possibilities. For example, it appears that maps based onone projection might be altered to satisfy the coordinates of a completely different projection. Note, for example, the change of parallels from concave to convex curves (Figs. 8A and 10A) and the change from converging meridians to diverging meridians (Figs. 8A and l0G). Similarly, the grids of maps B, F, and H of Fig. 10 approximate projections which are quite different from the original. Other
Inter-dimensional effects in nano-structures.
Dick, Rainer
2012-10-23
: We report on two extensions of the traditional analysis of low-dimensional structures in terms of low-dimensional quantum mechanics. On one hand, we discuss the impact of thermodynamics in one or two dimensions on the behavior of fermions in low-dimensional systems. On the other hand, we use both quantum wells and interfaces with different effective electron or hole mass to study the question when charge carriers in interfaces or layers exhibit two-dimensional or three-dimensional behavior. We find in particular that systems with different effective masses in the bulk and in the interface exhibit separation of two-dimensional and three-dimensional behavior on different length scales, whereas quantum wells exhibit linear combination of two-dimensional and three-dimensional behavior on short length scales while the behavior on large length scales cannot be associated with either two-dimensional or three-dimensional behavior.
Dust formation in Nova Del 2013
NASA Astrophysics Data System (ADS)
Shenavrin, V. I.; Taranova, O. G.; Tatarnikov, A. M.
2013-09-01
We present the result of the IR photometry of Nova Del 2013 obtained at the Crimean Station (Nauchny, Ukraine) of the Sternberg Astronomical Institute. JHKLM photometry was carried out with 125-cm telescope using a InSb-photometer on:
Gonadal dysgenesis in del (18p) syndrome
Telvi, L.; Ion, A.; Fouquet, F.
1995-07-17
We report on a girl with syndromal gonadal dysgenesis and a de novo del (18p). Genetic factors controlling gonadal development are located not only on the X chromosome, but also on autosomes. The present case suggests that one of these genes is situated on 18p. We conclude that patients with del (18p) syndrome should be evaluated for gonadal dysgenesis. 16 refs., 3 figs.
Tannenbaum, Eric P; Burns, Geoffrey T; Oak, Nikhil R; Lawton, Jeffrey N
2017-03-01
Metacarpal fractures are commonly treated by a variety of means including casting or open reduction internal fixation when unacceptable alignment is present following attempted closed reduction. Dorsal plating with either single-row 2-dimensional or double-row 3-dimensional plates has been proposed. This study's purpose was to determine if there are any differences in fixation construct stability under cyclic loading and subsequent load to failure between the lower profile 3-dimensional and the larger 2-dimensional plates in a metacarpal fracture gap sawbone model. Thirty metacarpal cortico-cancellous synthetic bones were cut with a 1.75-mm gap between the 2 fragments simulating mid-diaphyseal fracture comminution. Half of the metacarpals were plated with 2.0-mm locking 2-dimensional plates and half with 1.5-mm locking 3-dimensional plates. The plated metacarpals were mounted into a materials testing apparatus and cyclically loaded under cantilever bending for 2,000 cycles at 70 N, then 2,000 cycles at 120 N, and finally monotonically loaded to failure. Throughout testing, fracture gap sizes were measured, failure modes were recorded, and construct strength and stiffness values were calculated. All 3-dimensional constructs survived both cyclic loading conditions. Ten (67%) 2-dimensional constructs survived both loading conditions, whereas 5 (33%) failed the 120-N loading at 1377 ± 363 cycles. When loaded to failure, the 3-dimensional constructs failed at 265 N ± 21 N, whereas the 2-dimensional constructs surviving cyclic loading failed at 190 N ± 17 N. The shorter, thinner 3-dimensional metacarpal plates demonstrated increased resistance to failure in a cyclic loading model and increased load to failure compared with the relatively longer, thicker 2-dimensional metacarpal plates. The lower-profile 3-dimensional metacarpal plate fixation demonstrated greater stability for early postoperative resistance than the thicker 2-dimensional fixation, whereas the smaller
Educación sobre sexualidad y prevención del VIH: un diagnóstico para América Latina y el Caribe
DeMaria, Lisa M.; Galárraga, Omar; Campero, Lourdes; Walker, Dilys M.
2016-01-01
RESUMEN Objetivo Mostrar, a través de un diagnóstico en América Latina y el Caribe, el panorama legislativo y curricular sobre sexualidad y prevención contra el virus de inmunodeficiencia humana (VIH) en el ámbito escolar, contrastándolo con los comportamientos sexuales reportados en encuestas demográficas y de salud. Métodos En mayo de 2008 se realizó, con el apoyo del Fondo de Población de las Naciones Unidas (UNFPA), una encuesta a informantes clave en 34 países de la Región. El cuestionario autoaplicado solicitó información sustantiva de agentes de las diferentes partes interesadas, como ministerios de educación y de salud, sobre los programas de prevención contra el VIH/Sida que se están aplicando en las escuelas. Resultados Respondieron a la encuesta 27 países que representan 95,5% de la población objetivo (6 a 18 años de edad). La mayoría de los países informó tener al menos un libro de texto o un capítulo específico para enseñar los temas de educación sobre sexualidad y prevención del VIH. En la escuela secundaria se cubren la mayor parte de los temas pertinentes relevantes para la educación sobre sexualidad, pero no todos. Por ejemplo, el problema de la discriminación por orientación o preferencia sexual no se incluye en los programas escolares. Conclusiones El material educativo sobre sexualidad debe ser revisado y actualizado periódicamente de modo que refleje los avances en los temas y en la forma de tratar los contenidos. En cada país el currículo debe abordar el tema del respeto a la diversidad sobre orientación, preferencia e identidad sexuales, y en particular el manejo apropiado de la educación para prevenir infecciones de transmisión sexual (ITS) en hombres que tienen sexo con hombres. Los esfuerzos de evaluación de la efectividad de los programas deben contemplar desenlaces tales como marcadores biológicos (incidencia y prevalencia de ITS y embarazo) y no únicamente indicadores de conocimiento y
Dingenen, Bart; Staes, Filip F; Santermans, Lieselot; Steurs, Lien; Eerdekens, Maarten; Geentjens, Jurre; Peers, Koen H E; Thysen, Maarten; Deschamps, Kevin
2017-03-04
To investigate the temporal relationship between two-dimensional measured frontal plane joint angles and three-dimensional measured kinematic profiles during the stance phase of running, and to assess the intra- and intertester reliability of the two-dimensional angles. Observational study. Research laboratory. Fifteen injury-free elite athletes. Contralateral pelvic drop (CPD), femoral adduction (FA), hip adduction (HA) and knee valgus (KV) were measured at the deepest landing position during midstance with two-dimensional video analysis during running. CPD, HA and knee abduction were measured continuously during the entire stance phase through three-dimensional motion analysis. One-dimensional statistical parametric mapping was used to examine the temporal relationships between the two-dimensional angles and three-dimensional kinematic profiles. In addition, intra-class correlation coefficients (ICC) were calculated to assess the intra- and intertester reliability of the two-dimensional angles. Two-dimensional CPD, FA and HA were significantly related to the three-dimensional HA kinematic profile. Two-dimensional CPD was significantly related to the three-dimensional CPD kinematic profile. No significant relationship was found between two-dimensional KV and three-dimensional knee abduction. Excellent intra- and intertester reliability was found for the two-dimensional angles (ICC 0.90-0.99). These findings support implementing two-dimensional video analysis to evaluate CPD and HA during running. Copyright © 2017 Elsevier Ltd. All rights reserved.
High dimensional feature reduction via projection pursuit
NASA Technical Reports Server (NTRS)
Jimenez, Luis; Landgrebe, David
1994-01-01
The recent development of more sophisticated remote sensing systems enables the measurement of radiation in many more spectral intervals than previously possible. An example of that technology is the AVIRIS system, which collects image data in 220 bands. As a result of this, new algorithms must be developed in order to analyze the more complex data effectively. Data in a high dimensional space presents a substantial challenge, since intuitive concepts valid in a 2-3 dimensional space to not necessarily apply in higher dimensional spaces. For example, high dimensional space is mostly empty. This results from the concentration of data in the corners of hypercubes. Other examples may be cited. Such observations suggest the need to project data to a subspace of a much lower dimension on a problem specific basis in such a manner that information is not lost. Projection Pursuit is a technique that will accomplish such a goal. Since it processes data in lower dimensions, it should avoid many of the difficulties of high dimensional spaces. In this paper, we begin the investigation of some of the properties of Projection Pursuit for this purpose.
Prior Knowledge Enhances the Category Dimensionality Effect
Hoffman, Aaron B.; Harris, Harlan D.; Murphy, Gregory L.
2008-01-01
A study of the combined influence of prior knowledge and stimulus dimensionality on category learning was conducted. Subjects learned category structures with the same number of necessary dimensions but more or fewer additional redundant dimensions, and with either knowledge-related or knowledge-unrelated features. Minimal-learning models predict that all subjects, regardless of condition, should learn either the same number of dimensions, or else should respond more slowly to each dimension. Despite similar learning rates and response times, subjects learned more features in the high-dimensional than in the low-dimensional condition. Furthermore, prior knowledge interacted with dimensionality, increasing what was learned especially in the high-dimensional case. A second experiment confirmed that the participants did in fact learn more features during the training phase, rather than simply inferring them at test. These effects can be explained by direct associations among features (representing prior knowledge) combined with feedback between features and the category label, as shown by simulations of the knowledge-resonance, or KRES, model of category learning. PMID:18426059
Six dimensional QCD at two loops
NASA Astrophysics Data System (ADS)
Gracey, J. A.
2016-01-01
We construct the six-dimensional quantum chromodynamics (QCD) Lagrangian in a linear covariant gauge and subsequently renormalize it at two loops in the modified minimal subtraction (MS ¯ ) scheme. The coupling constant corresponding to the gauge interaction is asymptotically free for all numbers of quark fields, Nf. Analyzing the β functions yields a rich spectrum of fixed points. For instance, the conformal window in the six-dimensional theory is at Nf=16 for the S U (3 ) color group. The critical theory structure is similar to that of an O (N ) scalar theory in eight dimensions. Using the large-N expansion the latter is shown to be in the same universality class as the Heisenberg ferromagnet. Similarly using the large-Nf expansion, six-dimensional QCD is shown to be in the same class as the two-dimensional non-Abelian Thirring model and four-dimensional QCD. Abelian gauge theories are also renormalized at high loops in six and eight dimensions. It is shown that the gauge parameter only appears in the electron anomalous dimension at one loop, similar to four dimensions.
Dimensional measurements and operators in mathematical morphology
NASA Astrophysics Data System (ADS)
Soille, Pierre; Serra, Jean C.; Rivest, Jean-Francois
1992-04-01
In mathematical morphology, grey tone images are often considered as 3D Euclidean sets through their umbra or subgraph. This model allows one to extend measurements for sets to grey tone images. It has been shown that any valid measurement on Euclidean sets should satisfy some basic constraints such as invariance to displacements and to magnifications. However, when applied to subgraphs, these measurements may be meaningless as the image plane is not homogeneous with the grey tone axis. An additional constraint is introduced called dimensionality. This property holds for the inhomogeneity of image dimensions. A measurement on a grey tone image will be dimensional if the same measurement applied to this image after a magnification of its image plane and an affine transform of its grey tone axis can be related to the initial measure. The authors first recall valid measurements on sets and their properties. Then it is shown how to generalize to grey tone images and the dimensionality constraint is introduced. Set measurements are then reviewed to determine those satisfying the dimensionality criterion and consideration is given to the measure of the fractal dimension in the light of this new criterion. Eventually, dimensionality must also be considered when processing images. This is illustrated by a segmentation experiment.
Low-dimensional analysis of geomagnetic reversals
NASA Astrophysics Data System (ADS)
Morzfeld, M.; Fournier, A.; Hulot, G.
2015-12-01
Low-dimensional models for Earth's magnetic dipole have attracted attention recently because they may be a powerful tool to study the dominant dynamics over geological time-scales, where direct numerical simulation remains challenging. We investigate the extent to which several low-dimensional models can explain the Earth's dipole dynamics by comparing them to the signed relative paleointensity over the past 2 million years. Our comparisons of models and data are done by Bayesian statistics, which allows us to incorporate nonlinearity and uncertainty into the computations. The comparison, or data assimilation, reveals the strengths and weaknesses of each low-dimensional model and suggests improvements to the low-dimensional models. We also investigate if low-dimensional models can predict dipole reversals by performing extensive numerical experiments, and by hind-casting the Laschamp event, the Bruhnes-Matuyama reversal, as well as four other reversals documented over the past two million years. Our analysis stresses the need for models of geomagnetic reversals to faithfully account for the full spectrum of variability of paleomagnetic intensity.
New two dimensional compounds: beyond graphene
NASA Astrophysics Data System (ADS)
Lebegue, Sebastien
2015-03-01
In the field of nanosciences, the quest for materials with reduced dimensionality is only at its beginning. While a lot of effort has been put initially on graphene, the focus has been extended in the last past years to functionalized graphene, boron nitride, silicene, and transition metal dichalcogenides in the form of single layers. Although these two-dimensional compounds offer a larger range of properties than graphene, there is a constant need for new materials presenting equivalent or superior performances to the ones already known. Here I will present an approach that we have used to discover potential new two-dimensional materials. This approach corresponds to perform datamining in the Inorganic Crystal Structure Database using simple geometrical criterias, and allowed us to identify nearly 40 new materials that could be exfoliated into two-dimensional sheets. Then, their electronic structure (density of states and bandstructure) was obtained with density functional theory to predict whether the two-dimensional material is metallic or insulating, as well as if it undergoes magnetic ordering at low temperatures. If time allows, I will also present some of our recent results concerning the electronic structure of transition metal dichalcogenides bilayers.
NASA Astrophysics Data System (ADS)
Miao, Qian; Hu, Xiao-Rui; Chen, Yong
2014-02-01
We present a Maple computer algebra package, ONEOptimal, which can calculate one-dimensional optimal system of finite dimensional Lie algebra for nonlinear equations automatically based on Olver's theory. The core of this theory is viewing the Killing form of the Lie algebra as an invariant for the adjoint representation. Some examples are given to demonstrate the validity and efficiency of the program.
Simple Two-Dimensional Corrections for One-Dimensional Pulse Tube Models
NASA Technical Reports Server (NTRS)
Lee, J. M.; Kittel, P.; Timmerhaus, K. D.; Radebaugh, R.
2004-01-01
One-dimensional oscillating flow models are very useful for designing pulse tubes. They are simple to use, not computationally intensive, and the physical relationship between temperature, pressure and mass flow are easy to understand when used in conjunction with phasor diagrams. They do not possess, however, the ability to directly calculate thermal and momentum diffusion in the direction transverse to the oscillating flow. To account for transverse effects, lumped parameter corrections, which are obtained though experiment, must be used. Or two-dimensional solutions of the differential fluid equations must be obtained. A linear two-dimensional solution to the fluid equations has been obtained. The solution provides lumped parameter corrections for one-dimensional models. The model accounts for heat transfer and shear flow between the gas and the tube. The complex Nusselt number and complex shear wall are useful in describing these corrections, with phase relations and amplitudes scaled with the Prandtl and Valensi numbers. The calculated ratio, a, between a two-dimensional solution of the oscillating temperature and velocity and a one-dimensional solution for the same shows a scales linearly with Va for Va less than 30. In this region alpha less than 0.5, that is, the enthalpy flow calculated with a two-dimensional model is 50% of a calculation using a one-dimensional model. For Va greater than 250, alpha = 0.8, showing that diffusion is still important even when it is confined to a thing layer near the tube wall.
The Art of Extracting One-Dimensional Flow Properties from Multi-Dimensional Data Sets
NASA Technical Reports Server (NTRS)
Baurle, R. A.; Gaffney, R. L.
2007-01-01
The engineering design and analysis of air-breathing propulsion systems relies heavily on zero- or one-dimensional properties (e:g: thrust, total pressure recovery, mixing and combustion efficiency, etc.) for figures of merit. The extraction of these parameters from experimental data sets and/or multi-dimensional computational data sets is therefore an important aspect of the design process. A variety of methods exist for extracting performance measures from multi-dimensional data sets. Some of the information contained in the multi-dimensional flow is inevitably lost when any one-dimensionalization technique is applied. Hence, the unique assumptions associated with a given approach may result in one-dimensional properties that are significantly different than those extracted using alternative approaches. The purpose of this effort is to examine some of the more popular methods used for the extraction of performance measures from multi-dimensional data sets, reveal the strengths and weaknesses of each approach, and highlight various numerical issues that result when mapping data from a multi-dimensional space to a space of one dimension.
Picture Perception in Infants: Generalization from Two-Dimensional to Three-Dimensional Displays
ERIC Educational Resources Information Center
Jowkar-Baniani, Gelareh; Schmuckler, Mark A.
2011-01-01
Two experiments investigated 9-month-old infants' abilities to recognize the correspondence between an actual three-dimensional (3D) object and its two-dimensional (2D) representation, looking specifically at representations that did not literally depict the actual object: schematic line drawings. In Experiment 1, infants habituated to a line…
Dimensionality Reduction on Multi-Dimensional Transfer Functions for Multi-Channel Volume Data Sets
Kim, Han Suk; Schulze, Jürgen P.; Cone, Angela C.; Sosinsky, Gina E.; Martone, Maryann E.
2011-01-01
The design of transfer functions for volume rendering is a non-trivial task. This is particularly true for multi-channel data sets, where multiple data values exist for each voxel, which requires multi-dimensional transfer functions. In this paper, we propose a new method for multi-dimensional transfer function design. Our new method provides a framework to combine multiple computational approaches and pushes the boundary of gradient-based multi-dimensional transfer functions to multiple channels, while keeping the dimensionality of transfer functions at a manageable level, i.e., a maximum of three dimensions, which can be displayed visually in a straightforward way. Our approach utilizes channel intensity, gradient, curvature and texture properties of each voxel. Applying recently developed nonlinear dimensionality reduction algorithms reduces the high-dimensional data of the domain. In this paper, we use Isomap and Locally Linear Embedding as well as a traditional algorithm, Principle Component Analysis. Our results show that these dimensionality reduction algorithms significantly improve the transfer function design process without compromising visualization accuracy. We demonstrate the effectiveness of our new dimensionality reduction algorithms with two volumetric confocal microscopy data sets. PMID:21841914
Dimensionality Reduction on Multi-Dimensional Transfer Functions for Multi-Channel Volume Data Sets.
Kim, Han Suk; Schulze, Jürgen P; Cone, Angela C; Sosinsky, Gina E; Martone, Maryann E
2010-09-21
The design of transfer functions for volume rendering is a non-trivial task. This is particularly true for multi-channel data sets, where multiple data values exist for each voxel, which requires multi-dimensional transfer functions. In this paper, we propose a new method for multi-dimensional transfer function design. Our new method provides a framework to combine multiple computational approaches and pushes the boundary of gradient-based multi-dimensional transfer functions to multiple channels, while keeping the dimensionality of transfer functions at a manageable level, i.e., a maximum of three dimensions, which can be displayed visually in a straightforward way. Our approach utilizes channel intensity, gradient, curvature and texture properties of each voxel. Applying recently developed nonlinear dimensionality reduction algorithms reduces the high-dimensional data of the domain. In this paper, we use Isomap and Locally Linear Embedding as well as a traditional algorithm, Principle Component Analysis. Our results show that these dimensionality reduction algorithms significantly improve the transfer function design process without compromising visualization accuracy. We demonstrate the effectiveness of our new dimensionality reduction algorithms with two volumetric confocal microscopy data sets.
Creating Two-Dimensional Nets of Three-Dimensional Shapes Using "Geometer's Sketchpad"
ERIC Educational Resources Information Center
Maida, Paula
2005-01-01
This article is about a computer lab project in which prospective teachers used Geometer's Sketchpad software to create two-dimensional nets for three-dimensional shapes. Since this software package does not contain ready-made tools for creating non-regular or regular polygons, the students used prior knowledge and geometric facts to create their…
Application of Two-Dimensional AWE Algorithm in Training Multi-Dimensional Neural Network Model
2003-07-01
with the optimization one. Various well-known two-dimensional AWE is applied to accelerate the optimization techniques, such as genetic process of...1 output ayer Relue ay Reitv e Frequtency Dmnino Position of’ee Lene lfine fixed fixed Two-Dimensional AWE Algorith ~m tcrllnwf cei Output Vriables
Picture Perception in Infants: Generalization from Two-Dimensional to Three-Dimensional Displays
ERIC Educational Resources Information Center
Jowkar-Baniani, Gelareh; Schmuckler, Mark A.
2011-01-01
Two experiments investigated 9-month-old infants' abilities to recognize the correspondence between an actual three-dimensional (3D) object and its two-dimensional (2D) representation, looking specifically at representations that did not literally depict the actual object: schematic line drawings. In Experiment 1, infants habituated to a line…
The Extraction of One-Dimensional Flow Properties from Multi-Dimensional Data Sets
NASA Technical Reports Server (NTRS)
Baurle, Robert A.; Gaffney, Richard L., Jr.
2007-01-01
The engineering design and analysis of air-breathing propulsion systems relies heavily on zero- or one-dimensional properties (e.g. thrust, total pressure recovery, mixing and combustion efficiency, etc.) for figures of merit. The extraction of these parameters from experimental data sets and/or multi-dimensional computational data sets is therefore an important aspect of the design process. A variety of methods exist for extracting performance measures from multi-dimensional data sets. Some of the information contained in the multi-dimensional flow is inevitably lost when any one-dimensionalization technique is applied. Hence, the unique assumptions associated with a given approach may result in one-dimensional properties that are significantly different than those extracted using alternative approaches. The purpose of this effort is to examine some of the more popular methods used for the extraction of performance measures from multi-dimensional data sets, reveal the strengths and weaknesses of each approach, and highlight various numerical issues that result when mapping data from a multi-dimensional space to a space of one dimension.
Simulating higher-dimensional geometries in GADRAS using approximate one-dimensional solutions.
Thoreson, Gregory G.; Mitchell, Dean J; Harding, Lee T.
2013-02-01
The Gamma Detector Response and Analysis Software (GADRAS) software package is capable of simulating the radiation transport physics for one-dimensional models. Spherical shells are naturally one-dimensional, and have been the focus of development and benchmarking. However, some objects are not spherical in shape, such as cylinders and boxes. These are not one-dimensional. Simulating the radiation transport in two or three dimensions is unattractive because of the extra computation time required. To maintain computational efficiency, higher-dimensional geometries require approximations to simulate them in one-dimension. This report summarizes the theory behind these approximations, tests the theory against other simulations, and compares the results to experimental data. Based on the results, it is recommended that GADRAS users always attempt to approximate reality using spherical shells. However, if fissile material is present, it is imperative that the shape of the one-dimensional model matches the fissile material, including the use of slab and cylinder geometry.
Multi/infinite dimensional neural networks, multi/infinite dimensional logic theory.
Murthy, Garimella Rama
2005-06-01
A mathematical model of an arbitrary multi-dimensional neural network is developed and a convergence theorem for an arbitrary multi-dimensional neural network represented by a fully symmetric tensor is stated and proved. The input and output signal states of a multi-dimensional neural network/logic gate are related through an energy function, defined over the fully symmetric tensor (representing the connection structure of a multi-dimensional neural network). The inputs and outputs are related such that the minimum/maximum energy states correspond to the output states of the logic gate/neural network realizing a logic function. Similarly, a logic circuit consisting of the interconnection of logic gates, represented by a block symmetric tensor, is associated with a quadratic/higher degree energy function. Infinite dimensional logic theory is discussed through the utilization of infinite dimension/order tensors.
Chung, W. Joon; Goeckeler-Fried, Jennifer L.; Havasi, Viktoria; Chiang, Annette; Rowe, Steven M.; Plyler, Zackery E.; Hong, Jeong S.; Mazur, Marina; Piazza, Gary A.; Keeton, Adam B.; White, E. Lucile; Rasmussen, Lynn; Weissman, Allan M.; Denny, R. Aldrin; Brodsky, Jeffrey L.; Sorscher, Eric J.
2016-01-01
Small molecules that correct the folding defects and enhance surface localization of the F508del mutation in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) comprise an important therapeutic strategy for cystic fibrosis lung disease. However, compounds that rescue the F508del mutant protein to wild type (WT) levels have not been identified. In this report, we consider obstacles to obtaining robust and therapeutically relevant levels of F508del CFTR. For example, markedly diminished steady state amounts of F508del CFTR compared to WT CFTR are present in recombinant bronchial epithelial cell lines, even when much higher levels of mutant transcript are present. In human primary airway cells, the paucity of Band B F508del is even more pronounced, although F508del and WT mRNA concentrations are comparable. Therefore, to augment levels of “repairable” F508del CFTR and identify small molecules that then correct this pool, we developed compound library screening protocols based on automated protein detection. First, cell-based imaging measurements were used to semi-quantitatively estimate distribution of F508del CFTR by high content analysis of two-dimensional images. We evaluated ~2,000 known bioactive compounds from the NIH Roadmap Molecular Libraries Small Molecule Repository in a pilot screen and identified agents that increase the F508del protein pool. Second, we analyzed ~10,000 compounds representing diverse chemical scaffolds for effects on total CFTR expression using a multi-plate fluorescence protocol and describe compounds that promote F508del maturation. Together, our findings demonstrate proof of principle that agents identified in this fashion can augment the level of endoplasmic reticulum (ER) resident “Band B” F508del CFTR suitable for pharmacologic correction. As further evidence in support of this strategy, PYR-41—a compound that inhibits the E1 ubiquitin activating enzyme—was shown to synergistically enhance F508del rescue by C
Chung, W Joon; Goeckeler-Fried, Jennifer L; Havasi, Viktoria; Chiang, Annette; Rowe, Steven M; Plyler, Zackery E; Hong, Jeong S; Mazur, Marina; Piazza, Gary A; Keeton, Adam B; White, E Lucile; Rasmussen, Lynn; Weissman, Allan M; Denny, R Aldrin; Brodsky, Jeffrey L; Sorscher, Eric J
2016-01-01
Small molecules that correct the folding defects and enhance surface localization of the F508del mutation in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) comprise an important therapeutic strategy for cystic fibrosis lung disease. However, compounds that rescue the F508del mutant protein to wild type (WT) levels have not been identified. In this report, we consider obstacles to obtaining robust and therapeutically relevant levels of F508del CFTR. For example, markedly diminished steady state amounts of F508del CFTR compared to WT CFTR are present in recombinant bronchial epithelial cell lines, even when much higher levels of mutant transcript are present. In human primary airway cells, the paucity of Band B F508del is even more pronounced, although F508del and WT mRNA concentrations are comparable. Therefore, to augment levels of "repairable" F508del CFTR and identify small molecules that then correct this pool, we developed compound library screening protocols based on automated protein detection. First, cell-based imaging measurements were used to semi-quantitatively estimate distribution of F508del CFTR by high content analysis of two-dimensional images. We evaluated ~2,000 known bioactive compounds from the NIH Roadmap Molecular Libraries Small Molecule Repository in a pilot screen and identified agents that increase the F508del protein pool. Second, we analyzed ~10,000 compounds representing diverse chemical scaffolds for effects on total CFTR expression using a multi-plate fluorescence protocol and describe compounds that promote F508del maturation. Together, our findings demonstrate proof of principle that agents identified in this fashion can augment the level of endoplasmic reticulum (ER) resident "Band B" F508del CFTR suitable for pharmacologic correction. As further evidence in support of this strategy, PYR-41-a compound that inhibits the E1 ubiquitin activating enzyme-was shown to synergistically enhance F508del rescue by C18, a small
Three-dimensional separation and reattachment
NASA Technical Reports Server (NTRS)
Peake, D. J.; Tobak, M.
1982-01-01
The separation of three dimensional turbulent boundary layers from the lee of flight vehicles at high angles of attack is investigated. The separation results in dominant, large scale, coiled vortex motions that pass along the body in the general direction of the free stream. In all cases of three dimensional flow separation and reattachment, the assumption of continuous vector fields of skin friction lines and external flow streamlines, coupled with simple laws of topology, provides a flow grammar whose elemental constituents are the singular points: the nodes, spiral nodes (foci), and saddles. The phenomenon of three dimensional separation may be construed as either a local or a global event, depending on whether the skin friction line that becomes a line of separation originates at a node or a saddle point.
Topology of three-dimensional separated flows
NASA Technical Reports Server (NTRS)
Tobak, M.; Peake, D. J.
1981-01-01
Based on the hypothesis that patterns of skin-friction lines and external streamlines reflect the properties of continuous vector fields, topology rules define a small number of singular points (nodes, saddle points, and foci) that characterize the patterns on the surface and on particular projections of the flow (e.g., the crossflow plane). The restricted number of singular points and the rules that they obey are considered as an organizing principle whose finite number of elements can be combined in various ways to connect together the properties common to all steady three dimensional viscous flows. Introduction of a distinction between local and global properties of the flow resolves an ambiguity in the proper definition of a three dimensional separated flow. Adoption of the notions of topological structure, structural stability, and bifurcation provides a framework to describe how three dimensional separated flows originate and succeed each other as the relevant parameters of the problem are varied.
Three-dimensional separation and reattachment
NASA Technical Reports Server (NTRS)
Peake, D. J.; Tobak, M.
1982-01-01
The separation of three dimensional turbulent boundary layers from the lee of flight vehicles at high angles of attack is investigated. The separation results in dominant, large scale, coiled vortex motions that pass along the body in the general direction of the free stream. In all cases of three dimensional flow separation and reattachment, the assumption of continuous vector fields of skin friction lines and external flow streamlines, coupled with simple laws of topology, provides a flow grammar whose elemental constituents are the singular points: the nodes, spiral nodes (foci), and saddles. The phenomenon of three dimensional separation may be constrained as either a local or a global event, depending on whether the skin friction line that becomes a line of separation originates at a node or a saddle point.
3-Dimensional Topographic Models for the Classroom
NASA Technical Reports Server (NTRS)
Keller, J. W.; Roark, J. H.; Sakimoto, S. E. H.; Stockman, S.; Frey, H. V.
2003-01-01
We have recently undertaken a program to develop educational tools using 3-dimensional solid models of digital elevation data acquired by the Mars Orbital Laser Altimeter (MOLA) for Mars as well as a variety of sources for elevation data of the Earth. This work is made possible by the use of rapid prototyping technology to construct solid 3-Dimensional models of science data. We recently acquired rapid prototyping machine that builds 3-dimensional models in extruded plastic. While the machine was acquired to assist in the design and development of scientific instruments and hardware, it is also fully capable of producing models of spacecraft remote sensing data. We have demonstrated this by using Mars Orbiter Laser Altimeter (MOLA) topographic data and Earth based topographic data to produce extruded plastic topographic models which are visually appealing and instantly engage those who handle them.
Vision in our three-dimensional world.
Parker, Andrew J
2016-06-19
Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices.This article is part of the themed issue 'Vision in our three-dimensional world'. © 2016 The Author(s).
Vision in our three-dimensional world
2016-01-01
Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269595
Ligand-Stabilized Reduced-Dimensionality Perovskites.
Quan, Li Na; Yuan, Mingjian; Comin, Riccardo; Voznyy, Oleksandr; Beauregard, Eric M; Hoogland, Sjoerd; Buin, Andrei; Kirmani, Ahmad R; Zhao, Kui; Amassian, Aram; Kim, Dong Ha; Sargent, Edward H
2016-03-02
Metal halide perovskites have rapidly advanced thin-film photovoltaic performance; as a result, the materials' observed instabilities urgently require a solution. Using density functional theory (DFT), we show that a low energy of formation, exacerbated in the presence of humidity, explains the propensity of perovskites to decompose back into their precursors. We find, also using DFT, that intercalation of phenylethylammonium between perovskite layers introduces quantitatively appreciable van der Waals interactions. These drive an increased formation energy and should therefore improve material stability. Here we report reduced-dimensionality (quasi-2D) perovskite films that exhibit improved stability while retaining the high performance of conventional three-dimensional perovskites. Continuous tuning of the dimensionality, as assessed using photophysical studies, is achieved by the choice of stoichiometry in materials synthesis. We achieve the first certified hysteresis-free solar power conversion in a planar perovskite solar cell, obtaining a 15.3% certified PCE, and observe greatly improved performance longevity.
TWO-DIMENSIONAL TOPOLOGY OF COSMOLOGICAL REIONIZATION
Wang, Yougang; Xu, Yidong; Chen, Xuelei; Park, Changbom; Kim, Juhan E-mail: cbp@kias.re.kr
2015-11-20
We study the two-dimensional topology of the 21-cm differential brightness temperature for two hydrodynamic radiative transfer simulations and two semi-numerical models. In each model, we calculate the two-dimensional genus curve for the early, middle, and late epochs of reionization. It is found that the genus curve depends strongly on the ionized fraction of hydrogen in each model. The genus curves are significantly different for different reionization scenarios even when the ionized faction is the same. We find that the two-dimensional topology analysis method is a useful tool to constrain the reionization models. Our method can be applied to the future observations such as those of the Square Kilometre Array.
Three dimensional fabrication at small size scales
Leong, Timothy G.; Zarafshar, Aasiyeh M.; Gracias, David H.
2010-01-01
Despite the fact that we live in a three-dimensional (3D) world and macroscale engineering is 3D, conventional sub-mm scale engineering is inherently two-dimensional (2D). New fabrication and patterning strategies are needed to enable truly three-dimensionally-engineered structures at small size scales. Here, we review strategies that have been developed over the last two decades that seek to enable such millimeter to nanoscale 3D fabrication and patterning. A focus of this review is the strategy of self-assembly, specifically in a biologically inspired, more deterministic form known as self-folding. Self-folding methods can leverage the strengths of lithography to enable the construction of precisely patterned 3D structures and “smart” components. This self-assembling approach is compared with other 3D fabrication paradigms, and its advantages and disadvantages are discussed. PMID:20349446
Two-Dimensional NMR Lineshape Analysis
NASA Astrophysics Data System (ADS)
Waudby, Christopher A.; Ramos, Andres; Cabrita, Lisa D.; Christodoulou, John
2016-04-01
NMR titration experiments are a rich source of structural, mechanistic, thermodynamic and kinetic information on biomolecular interactions, which can be extracted through the quantitative analysis of resonance lineshapes. However, applications of such analyses are frequently limited by peak overlap inherent to complex biomolecular systems. Moreover, systematic errors may arise due to the analysis of two-dimensional data using theoretical frameworks developed for one-dimensional experiments. Here we introduce a more accurate and convenient method for the analysis of such data, based on the direct quantum mechanical simulation and fitting of entire two-dimensional experiments, which we implement in a new software tool, TITAN (TITration ANalysis). We expect the approach, which we demonstrate for a variety of protein-protein and protein-ligand interactions, to be particularly useful in providing information on multi-step or multi-component interactions.
Plasmonics with two-dimensional conductors.
Yoon, Hosang; Yeung, Kitty Y M; Kim, Philip; Ham, Donhee
2014-03-28
A wealth of effort in photonics has been dedicated to the study and engineering of surface plasmonic waves in the skin of three-dimensional bulk metals, owing largely to their trait of subwavelength confinement. Plasmonic waves in two-dimensional conductors, such as semiconductor heterojunction and graphene, contrast the surface plasmonic waves on bulk metals, as the former emerge at gigahertz to terahertz and infrared frequencies well below the photonics regime and can exhibit far stronger subwavelength confinement. This review elucidates the machinery behind the unique behaviours of the two-dimensional plasmonic waves and discusses how they can be engineered to create ultra-subwavelength plasmonic circuits and metamaterials for infrared and gigahertz to terahertz integrated electronics.
The dimensional design of machining technologies
NASA Astrophysics Data System (ADS)
Toca, A.; Stingaci, I.; Rusica, I.
2016-11-01
In the paper we analyze the mutual influence of constructive and technological dimensional links on conditions of formation of the machining accuracy sizes. It is shown, that the formation the sizes from technological locating datum surface demands higher accuracy of the technological sizes, but in this case, the machining allowances are more stable. At the formation the sizes by the means of transitions from technological locating datum surface to adjustment surface, the accuracy sizes is achieved without necessity of increase of an accuracy of the technological sizes, but thus, it is observed a growth of tolerances of the machining allowances and decreasing of the accuracy if some surface will not be machined. The dimensional optimality is not characterized only by the number of technological sizes, but it is necessary to take into account the growth (sometimes complicated) of the technological sizes accuracy (a case of formation of the sizes as closing link of dimensional chains).
Three-dimensional imaging modalities in endodontics.
Mao, Teresa; Neelakantan, Prasanna
2014-09-01
Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.
Three-dimensional imaging modalities in endodontics
Mao, Teresa
2014-01-01
Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome. PMID:25279337
Arching in three-dimensional clogging
NASA Astrophysics Data System (ADS)
Török, János; Lévay, Sára; Szabó, Balázs; Somfai, Ellák; Wegner, Sandra; Stannarius, Ralf; Börzsönyi, Tamás
2017-06-01
Arching in dry granular material is a long established concept, however it remains still an open question how three-dimensional orifices clog. We investigate by means of numerical simulations and experimental data how the outflow creates a blocked configuration of particles. We define the concave surface of the clogged dome by two independent methods (geometric and density based). The average shape of the cupola for spheres is almost a hemisphere but individual samples have large holes in the structure indicating a blocked state composed of two-dimensional force chains rather than three-dimensional objects. The force chain structure justifies this assumption. For long particles the clogged configurations display large variations, and in certain cases the empty region reaches a height of 5 hole diameters. These structures involve vertical walls consisting of horizontally placed stable stacking of particles.
Dimensional crossover in dipolar magnetic layers
NASA Astrophysics Data System (ADS)
Bulenda, M.; Täuber, U. C.; Schwabl, F.
2000-01-01
We investigate the static critical behaviour of a uniaxial magnetic layer, with finite thickness L in one direction, yet infinitely extended in the remaining d dimensions. The magnetic dipole-dipole interaction is taken into account. We apply a variant of Wilson's momentum shell renormalization group approach to describe the crossover between the critical behaviour of the 3D Ising, 2D Ising, 3D uniaxial dipolar, and the 2D uniaxial dipolar universality classes. The corresponding renormalization group fixed points are in addition to different effective dimensionalities characterized by distinct analytic structures of the propagator, and are consequently associated with varying upper critical dimensions. While the limiting cases can be discussed by means of dimensional icons/Journals/Common/epsilon" ALT="epsilon" ALIGN="TOP"/> expansions with respect to the appropriate upper critical dimensions, respectively, the crossover features must be addressed in terms of the renormalization group flow trajectories at fixed dimensionality d .
Three-dimensional effects on airfoils
NASA Technical Reports Server (NTRS)
Chevallier, J. P.
1983-01-01
The effects of boundary layer flows along the walls of wind tunnels were studied to validate the transfer of two dimensional calculations to three dimensional transonic flowfield calculations. Results from trials in various wind tunnels were examind to determine the effects of the wall boundary flow on the control surfaces of an airfoil. Models sliding along a groove in the wall of a channel at sub- and transonic speeds were examined, with the finding that with either nonuniformities in the groove, or even if the channel walls are uniform, the lateral boundary layer can cause variations in the central flow region or alter the onset of shock at the transition point. Models for the effects in both turbulence and in the absence of turbulence are formulated, and it is noted that the characteristics of individual wind tunnels must be studied to quantify any existing three dimensional effects.
Two-Dimensional NMR Lineshape Analysis
Waudby, Christopher A.; Ramos, Andres; Cabrita, Lisa D.; Christodoulou, John
2016-01-01
NMR titration experiments are a rich source of structural, mechanistic, thermodynamic and kinetic information on biomolecular interactions, which can be extracted through the quantitative analysis of resonance lineshapes. However, applications of such analyses are frequently limited by peak overlap inherent to complex biomolecular systems. Moreover, systematic errors may arise due to the analysis of two-dimensional data using theoretical frameworks developed for one-dimensional experiments. Here we introduce a more accurate and convenient method for the analysis of such data, based on the direct quantum mechanical simulation and fitting of entire two-dimensional experiments, which we implement in a new software tool, TITAN (TITration ANalysis). We expect the approach, which we demonstrate for a variety of protein-protein and protein-ligand interactions, to be particularly useful in providing information on multi-step or multi-component interactions. PMID:27109776
Three dimensional boundary conditions in supersonic flow
NASA Technical Reports Server (NTRS)
Rudman, S.; Marconi, F.
1981-01-01
A theoretical analysis of the flow pattern at a solid surface in three dimensional supersonic flow is presented. The additional information necessary to overcome the nonuniqueness associated with the body tangency condition in three dimensions was developed. The analysis is based on the fact that three dimensional waves propagate locally exactly as they do in axisymmetric flow when viewed in the osculating plane to the streamline. The supersonic flow over an infinite swept corner is examined by both the classical solution and the three dimensional solution in the osculating plane and the results are shown to be identical. A simple numerical algorithm is proposed which accounts for the three wave surfaces that interact at a solid boundary.
Low-dimensional Te-based nanostructures.
Wang, Qisheng; Safdar, Muhammad; Wang, Zhenxing; He, Jun
2013-07-26
Low-dimensional Te-based nanomaterials have attracted intense attention in recent years due to their novel physical properties including surface-state effects, photoelectricity, phase changes, and thermoelectricity. The recent development of synthesis methods of low-dimensional Te-based nanostructures is reviewed, such as van der Waals expitaxial growth and template-assisted solution-phase deposition. In addition, the unique properties of these materials, such as tunable surface states, high photoresponsivity, fast phase change, and high thermoelectricity figure of merit, are reviewed. The potential applications of low-dimensional Te-based nanostructures are broad but particularly promising for nanoscale electronic and photoelectronic devices. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Plasmonics with two-dimensional conductors
Yoon, Hosang; Yeung, Kitty Y. M.; Kim, Philip; Ham, Donhee
2014-01-01
A wealth of effort in photonics has been dedicated to the study and engineering of surface plasmonic waves in the skin of three-dimensional bulk metals, owing largely to their trait of subwavelength confinement. Plasmonic waves in two-dimensional conductors, such as semiconductor heterojunction and graphene, contrast the surface plasmonic waves on bulk metals, as the former emerge at gigahertz to terahertz and infrared frequencies well below the photonics regime and can exhibit far stronger subwavelength confinement. This review elucidates the machinery behind the unique behaviours of the two-dimensional plasmonic waves and discusses how they can be engineered to create ultra-subwavelength plasmonic circuits and metamaterials for infrared and gigahertz to terahertz integrated electronics. PMID:24567472
One-dimensional Gromov minimal filling problem
NASA Astrophysics Data System (ADS)
Ivanov, Alexandr O.; Tuzhilin, Alexey A.
2012-05-01
The paper is devoted to a new branch in the theory of one-dimensional variational problems with branching extremals, the investigation of one-dimensional minimal fillings introduced by the authors. On the one hand, this problem is a one-dimensional version of a generalization of Gromov's minimal fillings problem to the case of stratified manifolds. On the other hand, this problem is interesting in itself and also can be considered as a generalization of another classical problem, the Steiner problem on the construction of a shortest network connecting a given set of terminals. Besides the statement of the problem, we discuss several properties of the minimal fillings and state several conjectures. Bibliography: 38 titles.
3-Dimensional Topographic Models for the Classroom
NASA Technical Reports Server (NTRS)
Keller, J. W.; Roark, J. H.; Sakimoto, S. E. H.; Stockman, S.; Frey, H. V.
2003-01-01
We have recently undertaken a program to develop educational tools using 3-dimensional solid models of digital elevation data acquired by the Mars Orbital Laser Altimeter (MOLA) for Mars as well as a variety of sources for elevation data of the Earth. This work is made possible by the use of rapid prototyping technology to construct solid 3-Dimensional models of science data. We recently acquired rapid prototyping machine that builds 3-dimensional models in extruded plastic. While the machine was acquired to assist in the design and development of scientific instruments and hardware, it is also fully capable of producing models of spacecraft remote sensing data. We have demonstrated this by using Mars Orbiter Laser Altimeter (MOLA) topographic data and Earth based topographic data to produce extruded plastic topographic models which are visually appealing and instantly engage those who handle them.
Localized shear generates three-dimensional transport
NASA Astrophysics Data System (ADS)
Smith, Lachlan D.; Rudman, Murray; Lester, Daniel R.; Metcalfe, Guy
2017-04-01
Understanding the mechanisms that control three-dimensional (3D) fluid transport is central to many processes, including mixing, chemical reaction, and biological activity. Here a novel mechanism for 3D transport is uncovered where fluid particles are kicked between streamlines near a localized shear, which occurs in many flows and materials. This results in 3D transport similar to Resonance Induced Dispersion (RID); however, this new mechanism is more rapid and mutually incompatible with RID. We explore its governing impact with both an abstract 2-action flow and a model fluid flow. We show that transitions from one-dimensional (1D) to two-dimensional (2D) and 2D to 3D transport occur based on the relative magnitudes of streamline jumps in two transverse directions.
Clustering high dimensional data using RIA
NASA Astrophysics Data System (ADS)
Aziz, Nazrina
2015-05-01
Clustering may simply represent a convenient method for organizing a large data set so that it can easily be understood and information can efficiently be retrieved. However, identifying cluster in high dimensionality data sets is a difficult task because of the curse of dimensionality. Another challenge in clustering is some traditional functions cannot capture the pattern dissimilarity among objects. In this article, we used an alternative dissimilarity measurement called Robust Influence Angle (RIA) in the partitioning method. RIA is developed using eigenstructure of the covariance matrix and robust principal component score. We notice that, it can obtain cluster easily and hence avoid the curse of dimensionality. It is also manage to cluster large data sets with mixed numeric and categorical value.
Clustering high dimensional data using RIA
Aziz, Nazrina
2015-05-15
Clustering may simply represent a convenient method for organizing a large data set so that it can easily be understood and information can efficiently be retrieved. However, identifying cluster in high dimensionality data sets is a difficult task because of the curse of dimensionality. Another challenge in clustering is some traditional functions cannot capture the pattern dissimilarity among objects. In this article, we used an alternative dissimilarity measurement called Robust Influence Angle (RIA) in the partitioning method. RIA is developed using eigenstructure of the covariance matrix and robust principal component score. We notice that, it can obtain cluster easily and hence avoid the curse of dimensionality. It is also manage to cluster large data sets with mixed numeric and categorical value.
Higher dimensional numerical relativity: Code comparison
NASA Astrophysics Data System (ADS)
Witek, Helvi; Okawa, Hirotada; Cardoso, Vitor; Gualtieri, Leonardo; Herdeiro, Carlos; Shibata, Masaru; Sperhake, Ulrich; Zilhão, Miguel
2014-10-01
The nonlinear behavior of higher dimensional black hole spacetimes is of interest in several contexts, ranging from an understanding of cosmic censorship to black hole production in high-energy collisions. However, nonlinear numerical evolutions of higher dimensional black hole spacetimes are tremendously complex, involving different diagnostic tools and "dimensional reduction methods." In this work we compare two different successful codes to evolve Einstein's equations in higher dimensions, and show that the results of such different procedures agree to numerical precision, when applied to the collision from rest of two equal-mass black holes. We calculate the total radiated energy to be Erad/M =(9.0±0.5)×10-4 in five dimensions and Erad/M=(8.1±0.4)×10-4 in six dimensions.
Unidades del paisaje de Puerto Rico: la influencia del clima, el substrato y la topografia
William Gould; Michael E. Jimenez; Gary Potts; Maya Quinones; Sebastian Martinuzzi
2008-01-01
El mapa de unidades del paisaje de Puerto Rico representa variaciones climaticas, topograficas y del substrato mediante la integracion de seis zonas climaticas (Ewel y Whitmore, 1973), seis substratos (Bawiec, 2001; USGS, 2005), cinco posiciones topograficas, o topoformas (Martinuzzi et al. 2007), y cuerpos de agua (USGS 2005). Los substratos representan el conjunto...
Spectral Dimensionality and Scale of Urban Radiance
NASA Technical Reports Server (NTRS)
Small, Christopher
2001-01-01
Characterization of urban radiance and reflectance is important for understanding the effects of solar energy flux on the urban environment as well as for satellite mapping of urban settlement patterns. Spectral mixture analyses of Landsat and Ikonos imagery suggest that the urban radiance field can very often be described with combinations of three or four spectral endmembers. Dimensionality estimates of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) radiance measurements of urban areas reveal the existence of 30 to 60 spectral dimensions. The extent to which broadband imagery collected by operational satellites can represent the higher dimensional mixing space is a function of both the spatial and spectral resolution of the sensor. AVIRIS imagery offers the spatial and spectral resolution necessary to investigate the scale dependence of the spectral dimensionality. Dimensionality estimates derived from Minimum Noise Fraction (MNF) eigenvalue distributions show a distinct scale dependence for AVIRIS radiance measurements of Milpitas, California. Apparent dimensionality diminishes from almost 40 to less than 10 spectral dimensions between scales of 8000 m and 300 m. The 10 to 30 m scale of most features in urban mosaics results in substantial spectral mixing at the 20 m scale of high altitude AVIRIS pixels. Much of the variance at pixel scales is therefore likely to result from actual differences in surface reflectance at pixel scales. Spatial smoothing and spectral subsampling of AVIRIS spectra both result in substantial loss of information and reduction of apparent dimensionality, but the primary spectral endmembers in all cases are analogous to those found in global analyses of Landsat and Ikonos imagery of other urban areas.
Spectral Dimensionality and Scale of Urban Radiance
NASA Technical Reports Server (NTRS)
Small, Christopher
2001-01-01
Characterization of urban radiance and reflectance is important for understanding the effects of solar energy flux on the urban environment as well as for satellite mapping of urban settlement patterns. Spectral mixture analyses of Landsat and Ikonos imagery suggest that the urban radiance field can very often be described with combinations of three or four spectral endmembers. Dimensionality estimates of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) radiance measurements of urban areas reveal the existence of 30 to 60 spectral dimensions. The extent to which broadband imagery collected by operational satellites can represent the higher dimensional mixing space is a function of both the spatial and spectral resolution of the sensor. AVIRIS imagery offers the spatial and spectral resolution necessary to investigate the scale dependence of the spectral dimensionality. Dimensionality estimates derived from Minimum Noise Fraction (MNF) eigenvalue distributions show a distinct scale dependence for AVIRIS radiance measurements of Milpitas, California. Apparent dimensionality diminishes from almost 40 to less than 10 spectral dimensions between scales of 8000 m and 300 m. The 10 to 30 m scale of most features in urban mosaics results in substantial spectral mixing at the 20 m scale of high altitude AVIRIS pixels. Much of the variance at pixel scales is therefore likely to result from actual differences in surface reflectance at pixel scales. Spatial smoothing and spectral subsampling of AVIRIS spectra both result in substantial loss of information and reduction of apparent dimensionality, but the primary spectral endmembers in all cases are analogous to those found in global analyses of Landsat and Ikonos imagery of other urban areas.
Four-dimensional CDT with toroidal topology
NASA Astrophysics Data System (ADS)
Ambjørn, J.; Gizbert-Studnicki, J.; Görlich, A.; Grosvenor, K.; Jurkiewicz, J.
2017-09-01
3 + 1 dimensional Causal Dynamical Triangulations (CDT) describe a quantum theory of fluctuating geometries without the introduction of a background geometry. If the topology of space is constrained to be that of a three-dimensional torus we show that the system will fluctuate around a dynamically formed background geometry which can be understood from a simple minisuperspace action which contains both a classical part and a quantum part. We determine this action by integrating out degrees of freedom in the full model, as well as by transfer matrix methods.
A Psychophysical Approach to Dimensional Integrality
1980-03-01
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Dimensionality switching in molecule-based magnets.
Goddard, P. A.; Manson, J. L.; Singleton, J.; Franke, I.; Lancaster, T.; Steele, A. J.; Blundell, S. J.; Baines, C.; Pratt, F.; McDonald, R. D.; Valenzuela, O. A.; Sengupta, P.; Corbeyl, J. F.; Southerland, H. I.; Schlueter, J. A.
2012-01-01
Gaining control of the building blocks of magnetic materials and thereby achieving particular characteristics will make possible the design and growth of bespoke magnetic devices. While progress in the synthesis of molecular materials, and especially coordination polymers, represents a significant step towards this goal, the ability to tune the magnetic interactions within a particular framework remains in its infancy. Here we demonstrate a chemical method which achieves dimensionality selection via preferential inhibition of the magnetic exchange in an S=1/2 antiferromagnet along one crystal direction, switching the system from being quasi-two- to quasi-one-dimensional while effectively maintaining the nearest-neighbor coupling strength.
Mobility anisotropy of two-dimensional semiconductors
NASA Astrophysics Data System (ADS)
Lang, Haifeng; Zhang, Shuqing; Liu, Zhirong
2016-12-01
The carrier mobility of anisotropic two-dimensional semiconductors under longitudinal acoustic phonon scattering was theoretically studied using deformation potential theory. Based on the Boltzmann equation with the relaxation time approximation, an analytic formula of intrinsic anisotropic mobility was derived, showing that the influence of effective mass on mobility anisotropy is larger than those of deformation potential constant or elastic modulus. Parameters were collected for various anisotropic two-dimensional materials (black phosphorus, Hittorf's phosphorus, BC2N , MXene, TiS3, and GeCH3) to calculate their mobility anisotropy. It was revealed that the anisotropic ratio is overestimated by the previously described method.
Higher dimensional charged gravastar admitting conformal motion
NASA Astrophysics Data System (ADS)
Bhar, Piyali
2014-12-01
In the present paper we have discussed about the higher dimensional charged gravastar admitting conformal motion. The gravastar, gravitationally vacuum condense star is generally considered as the alternative to black hole which has three regions with three different equation of state. (i) In interior region p=- ρ, (ii) in shell p= ρ, (iii) in exterior region p= ρ=0. p=- ρ is generally called the `false vacuum' or `degenerate vacuum' or ρ vacuum. We match our interior spacetime to the R-N higher dimensional spacetime in presence of thin shell.
Small firm subsistence and market dimensionality
NASA Astrophysics Data System (ADS)
Bruggeman, Jeroen; Péli, Gábor
2014-04-01
In many markets, large and small firms coexist. As large firms can in principle out-compete small ones, the actual presence of the latter asks for an explanation. In ours, we focus on the dimensionality of markets, which can change as a consequence of product innovations, preference elaboration or institutions. We show that increasing market dimensionality substantially enlarges the market periphery relative to the market center, which creates new potential niches for small firms. We thereby provide a parsimonious explanation for small firm subsistence.
Dimensionality of high temperature superconductivity in oxides
NASA Technical Reports Server (NTRS)
Chu, C. W.
1989-01-01
Many models have been proposed to account for the high temperature superconductivity observed in oxide systems. Almost all of these models proposed are based on the uncoupled low dimensional carrier Cu-O layers of the oxides. Results of several experiments are presented and discussed. They suggest that the high temperature superconductivity observed cannot be strictly two- or one-dimensional, and that the environment between the Cu-O layers and the interlayer coupling play an important role in the occurrence of such high temperature superconductivity. A comment on the very short coherence length reported is also made.
Fabrication of three dimensional microstructure fiber
NASA Astrophysics Data System (ADS)
Luo, Ying; Ma, Jie; Chen, Zhe; Lu, Huihui; Zhong, Yongchun
2015-05-01
A method of fabricating three dimensional (3D) microstructured fiber is presented. Polystyrene (PS) microspheres were coated around the surface of a micro-fiber through isothermal heating evaporation induced self-assembly method. Scanning electron microscopy (SEM) image shows that the colloidal crystal has continuous, uniform, and well-ordered face-centered cubic (FCC) structure, with [111] crystallographic direction normal to the surface of micro-fiber. This micro-fiber with three-dimensional photonic crystals structure is very useful in the applications of micro-fiber sensors or filters.
Three-dimensional topological insulators and bosonization
NASA Astrophysics Data System (ADS)
Cappelli, Andrea; Randellini, Enrico; Sisti, Jacopo
2017-05-01
Massless excitations at the surface of three-dimensional time-reversal invariant topological insulators possess both fermionic and bosonic descriptions, originating from band theory and hydrodynamic BF theory, respectively. We analyze the corresponding field theories of the Dirac fermion and compactified boson and compute their partition functions on the three-dimensional torus geometry. We then find some non-dynamic exact properties of bosonization in (2+1) dimensions, regarding fermion parity and spin sectors. Using these results, we extend the Fu-Kane-Mele stability argument to fractional topological insulators in three dimensions.
One-dimensional circular diffraction patterns
NASA Astrophysics Data System (ADS)
Daimon, Hiroshi; Ino, Shozo
1989-11-01
Circular diffraction patterns from a bulk crystal have been found in MEED patterns by using a newly developed two-dimensional spherical mirror analyzer. From the analysis of the energy dependence of their radii and from the fact that they are not associated with the tangential Kikuchi lines, the circles were interpreted by the concept of one-dimensional diffraction along the crystallographic axes. The hemi-circular patterns, which have been observed in RHEED patterns near superstructural spots from a surface structure, were also explained by this concept.
A dimensionality reducing model for distributed filtering.
NASA Technical Reports Server (NTRS)
Angel, E.; Jain, A. K.
1973-01-01
An approach is made to filtering of two-dimensional steady-state problems based on the notion of nearest neighbor interaction, i.e., at a given point in the spatial grid, the value at the variable of interest can be assumed to depend only on the values at adjacent grid points. It is shown that for linear steady-state problems significant dimensionality reductions can be accomplished. It was possible to achieve the desired results using a small amount of computer time and without getting into stability difficulties.
Three-dimensional displays and stereo vision.
Westheimer, Gerald
2011-08-07
Procedures for three-dimensional image reconstruction that are based on the optical and neural apparatus of human stereoscopic vision have to be designed to work in conjunction with it. The principal methods of implementing stereo displays are described. Properties of the human visual system are outlined as they relate to depth discrimination capabilities and achieving optimal performance in stereo tasks. The concept of depth rendition is introduced to define the change in the parameters of three-dimensional configurations for cases in which the physical disposition of the stereo camera with respect to the viewed object differs from that of the observer's eyes.
Three-dimensional crack closure behavior
NASA Technical Reports Server (NTRS)
Dawicke, D. S.; Grandt, A. F., Jr.; Newman, J. C., Jr.
1990-01-01
A crack closure measurement technique involving fatigue striations was used to produce a three-dimensional crack opening load profile for 2024-T351 aluminum alloy. The crack opening load profile, determined through the specimen thickness, was compared with crack opening load measurements made with strain gages and displacement gages. The results of this study indicate that a significant three-dimensional variation in crack closure behavior occurs in the alloy examined. An understanding of this phehomenon is important in understanding crack growth behavior, predicting crack shape changes, and interpreting 'standard' crack closure measurement techniques.
Entropy exchange for infinite-dimensional systems
Duan, Zhoubo; Hou, Jinchuan
2017-01-01
In this paper the entropy exchange for channels and states in infinite-dimensional systems are defined and studied. It is shown that, this entropy exchange depends only on the given channel and the state. An explicit expression of the entropy exchange in terms of the state and the channel is proposed. The generalized Klein’s inequality, the subadditivity and the triangle inequality about the entropy including infinite entropy for the infinite-dimensional systems are established, and then, applied to compare the entropy exchange with the entropy change. PMID:28164995
Three-dimensional magnetic bubble memory system
NASA Technical Reports Server (NTRS)
Stadler, Henry L. (Inventor); Katti, Romney R. (Inventor); Wu, Jiin-Chuan (Inventor)
1994-01-01
A compact memory uses magnetic bubble technology for providing data storage. A three-dimensional arrangement, in the form of stacks of magnetic bubble layers, is used to achieve high volumetric storage density. Output tracks are used within each layer to allow data to be accessed uniquely and unambiguously. Storage can be achieved using either current access or field access magnetic bubble technology. Optical sensing via the Faraday effect is used to detect data. Optical sensing facilitates the accessing of data from within the three-dimensional package and lends itself to parallel operation for supporting high data rates and vector and parallel processing.
ERIC Educational Resources Information Center
LaGreca, Nancy
2012-01-01
This study explores the intertextuality between Aurora Caceres's "La rosa muerta" (1914) and the novel "Del amor, del dolor y del vicio" (1898) by her ex-husband, Enrique Gomez Carrillo. Caceres strategically mentions Gomez Carrillo's novel in "La rosa muerta" to invite a reading of her work in dialogue with his. Both narratives follow the sexual…
ERIC Educational Resources Information Center
LaGreca, Nancy
2012-01-01
This study explores the intertextuality between Aurora Caceres's "La rosa muerta" (1914) and the novel "Del amor, del dolor y del vicio" (1898) by her ex-husband, Enrique Gomez Carrillo. Caceres strategically mentions Gomez Carrillo's novel in "La rosa muerta" to invite a reading of her work in dialogue with his. Both narratives follow the sexual…
Cánovas-Conesa, A.; Gomariz-Peñalver, V.; Sánchez-Sauco, M.F.; Vega, D.C. Jaimes; Ortega-García, J.A.; García, M.J. Aranda; Marín, J.L. Delgado; Ascanio, A. Trujillo; Hernández, F. López; Jimenez, J.I. Ruiz; de Paco Matallana, C.; Soldin, O.P.; Solís, M. Sánchez
2016-01-01
Resumen Objetivos El objetivo de este estudio fue estudiar la asociación de la adherencia a la dieta mediterránea materna al inicio del embarazo y el riesgo de gastrosquisis en la descendencia. Métodos Estudio de casos-control. 11 casos incidentes de gastrosquisis en la Región de Murcia de 2007 a 2012 y 34 controles concurrentes. Cuestionario validado de Frecuencia Alimentaria (CFA) sobre la dieta periconcepcional de 98 ítems realizado ‘cara a cara’ en el momento del diagnóstico. Factores confundidores: tabaquismo, expositión a cannabis/marihuana, edad materna y paterna, índice de masa corporal, ingresos económicos y nivel de estudios. Estudio descriptivo y regresión logística multivariable. Resultados Las madres de niños con gastrosquisis son más jóvenes (20,8 años; IC 95% 17,3–24,2) y su dieta tiene un menor aporte calórico, de grasas saturadas y monoinsaturadas y de proteínas que los controles. Odds Ratio (OR) en el modelo multivariable controlado por los factores confundidores: edad materna (años) 0,70 (IC95% 0,51–0,96); ácidos grasos monoinsaturados (oleico, g) 0,79 (IC95% 0,65–0,97) y consumo de vegetales (raciones/semana) 0,70 (IC95% 0,48–1,00). Conclusiones Una dieta materna rica en ácido oleico y productos vegetales podría contribuir a prevenir el riesgo de oclusión vascular de las arterias onfalomesentéricas, disminuyendo el riesgo de gastrosquisis. PMID:23833926
NASA Astrophysics Data System (ADS)
Bayuelo, Ezequiel
Este estudio examino y comparo las actitudes de los candidatos a maestros de ciencias y los maestros de ciencias en servicio acerca de la utilizacion de las herramientas computadorizadas en las clases de ciencias. Tambien identifico y diferencio el uso que ellos dan a estas herramientas en las clases de ciencias. Este estudio presenta un diseno descriptivo exploratorio. Constituyeron la muestra trescientos diez sujetos que fueron candidatos a maestros de ciencias o maestros de ciencias en servicio. Para recoger los datos se construyo y valido un cuestionario de treinta y un itemes. Se utilizaron las pruebas estadisticas no parametricas Kruskal Wallis y Chi-cuadrado (test de homogeneidad) para establecer las diferencias entre las actitudes de los sujetos con relacion al uso de las herramientas computadorizadas en las clases de ciencias. Los hallazgos evidenciaron que son positivas y muy parecidas las actitudes de los candidatos a maestros y maestros en servicio hacia el uso de las herramientas computadorizadas. No hubo diferencias entre los candidatos y maestros en servicio en terminos de las actitudes de confianza y empatia hacia el uso de las herramientas computadorizadas en las clases de ciencias. En aspectos como el uso del banco de datos bibliografico Eric y el uso de las herramientas computadorizadas en actividades educativas como explorar conceptos, conceptuar, aplicar lo aprendido y hacer asignaciones hubo diferencias estadisticamente significativas entre los candidatos y los maestros en servicio. Al comparar las frecuencias observadas con las esperadas hubo mas maestros en servicio y menos candidatos que indicaron usar el anterior banco de datos y las herramientas computadorizadas en las mencionadas actividades educativas.
Three-dimensional structure of a sunspot light bridge
NASA Astrophysics Data System (ADS)
Felipe, T.; Collados, M.; Khomenko, E.; Kuckein, C.; Asensio Ramos, A.; Balthasar, H.; Berkefeld, T.; Denker, C.; Feller, A.; Franz, M.; Hofmann, A.; Joshi, J.; Kiess, C.; Lagg, A.; Nicklas, H.; Orozco Suárez, D.; Pastor Yabar, A.; Rezaei, R.; Schlichenmaier, R.; Schmidt, D.; Schmidt, W.; Sigwarth, M.; Sobotka, M.; Solanki, S. K.; Soltau, D.; Staude, J.; Strassmeier, K. G.; Volkmer, R.; von der Lühe, O.; Waldmann, T.
2016-11-01
Context. Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar physics. Light bridges are commonly present during sunspot decay, but a comprehensive picture of their role in the removal of the photospheric magnetic field is still lacking. Aims: We study the three-dimensional configuration of a sunspot, and in particular, its light bridge, during one of the last stages of its decay. Methods: We present the magnetic and thermodynamical stratification inferred from full Stokes inversions of the photospheric Si i 10 827 Å and Ca i 10 839 Å lines obtained with the GREGOR Infrared Spectrograph of the GREGOR telescope at the Observatorio del Teide, Tenerife, Spain. The analysis is complemented by a study of continuum images covering the disk passage of the active region, which are provided by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Results: The sunspot shows a light bridge with penumbral continuum intensity that separates the central umbra from a smaller umbra. We find that in this region the magnetic field lines form a canopy with lower magnetic field strength in the inner part. The photospheric light bridge is dominated by gas pressure (high-β), as opposed to the surrounding umbra, where the magnetic pressure is higher. A convective flow is observed in the light bridge. This flow is able to bend the magnetic field lines and to produce field reversals. The field lines merge above the light bridge and become as vertical and strong as in the surrounding umbra. We conclude that this occurs because two highly magnetized regions approach each other during the sunspot evolution. Movies associated to Figs. 2 and 13 are available at http://www.aanda.org
Three-dimensional chiral photonic superlattices.
Thiel, M; Fischer, H; von Freymann, G; Wegener, M
2010-01-15
We investigate three-dimensional photonic superlattices composed of polymeric helices in various spatial checkerboard-like arrangements. Depending on the relative phase shift and handedness of the chiral building blocks, different circular-dichroism resonances appear or are suppressed. Samples corresponding to four different configurations are fabricated by direct laser writing. The measured optical transmittance spectra are in good agreement with numerical calculations.
Electronic structure of one-dimensional cuprates
NASA Astrophysics Data System (ADS)
Maiti, K.; Sarma, D. D.; Mizokawa, T.; Fujimori, A.
1998-01-01
We have investigated the electronic structures of one-dimensional antiferromagnetic insulators Ca2CuO3 and Sr2CuO3 combining electron spectroscopic measurements and various calculations. While calculations based on a local-spin-density approach for the real magnetic structures fail to yield an insulating state, from our experiments we estimate the intrinsic band gaps in these materials to be about 1.7 eV (Ca2CuO3) and 1.5 eV (Sr2CuO3). Analysis of the core-level and the valence-band spectra in terms of model many-body Hamiltonians show that the charge-transfer energy Δ for these one-dimensional systems is significantly smaller than other cuprates, such as the high-Tc oxides (two-dimensional) and CuO (three-dimensional). Such a small Δ suggests the presence of the bare upper Hubbard band within the oxygen p bandwidth and thus provides an example of a correlated covalent insulator.
Two and three dimensional magnetotelluric inversion
Booker, J.
1993-01-01
Electrical conductivity depends on properties such as the presence of ionic fluids in interconnected pores that are difficult to sense with other remote sensing techniques. Thus improved imaging of underground electrical structure has wide practical importance in exploring for groundwater, mineral and geothermal resources, and in assessing the diffusion of fluids in oil fields and waste sites. Because the electromagnetic inverse problem is fundamentally multi-dimensional, most imaging algorithms saturate available computer power long before they can deal with the complete data set. We have developed an algorithm to directly invert large multi-dimensional data sets that is orders of magnitude faster than competing methods. We have proven that a two-dimensional (2D) version of the algorithm is highly effective for real data and have made substantial progress towards a three-dimensional (3D) version. We are proposing to cure identified shortcomings and substantially expand the utility of the existing 2D program, overcome identified difficulties with extending our method to three-dimensions (3D) and embark on an investigation of related EM imaging techniques which may have the potential for even further increasing resolution.
Three-dimensional RF structure calculations
NASA Astrophysics Data System (ADS)
Cooper, R. K.; Browman, M. J.; Weiland, T.
1989-04-01
The calculation of three-dimensional rf structures is rapidly approaching adolescence, after having been in its infancy for the last four years. This paper will show the kinds of calculations that are currently being performed in the frequency domain and is a companion paper to one in which time-domain calculations are described.
Three-dimensional rf structure calculations
Cooper, R.K.; Browman, M.J.; Weiland, T.
1988-01-01
The calculation of three-dimensional rf structures is rapidly approaching adolescence, after having been in its infancy for the last four years. This paper will show the kinds of calculations that are currently being performed in the frequency domain and is a companion paper to one in which time-domain calculations are described. 13 refs., 14 figs.
Two-Dimensional Motions of Rockets
ERIC Educational Resources Information Center
Kang, Yoonhwan; Bae, Saebyok
2007-01-01
We analyse the two-dimensional motions of the rockets for various types of rocket thrusts, the air friction and the gravitation by using a suitable representation of the rocket equation and the numerical calculation. The slope shapes of the rocket trajectories are discussed for the three types of rocket engines. Unlike the projectile motions, the…
High-resolution two dimensional advective transport
Smith, P.E.; Larock, B.E.
1989-01-01
The paper describes a two-dimensional high-resolution scheme for advective transport that is based on a Eulerian-Lagrangian method with a flux limiter. The scheme is applied to the problem of pure-advection of a rotated Gaussian hill and shown to preserve the monotonicity property of the governing conservation law.
Growing Three-Dimensional Cocultures Of Cells
NASA Technical Reports Server (NTRS)
Wolf, David A.; Goodwin, Thomas J.
1995-01-01
Laboratory process provides environmental conditions favoring simultaneous growth of cocultures of mammalian cells of more than one type. Cultures become three-dimensional tissuelike assemblies serving as organoid models of differentiation of cells. Process used, for example, to study growth of human colon cancers, starting from mixtures of normal colonic fibroblasts and partially differentiated colon adenocarcinoma cells.
Spectral tomography of three-dimensional objects
Bulygin, F.V.; Levin, G.G.
1995-12-01
Spectral tomography is a new field in optical tomography concerned with studies of the internal space-spectral structure of polychromatic objects. In this paper, methods for obtaining projections spectral structure of three-dimensional objects and algorithms for its reconstruction are proposed and described. The results of the spectral-tomography reconstruction of the object structure are presented. 6 refs., 4 figs.
Dimensionally Stable Graphite-Fiber/Glass Composites
NASA Technical Reports Server (NTRS)
Harris, Robert; Bergen, George J.; Studer, Philip A.
1992-01-01
Method of making composites of glass matrices reinforced by graphite fibers provides for control of proportions, orientations, and distributions of fibers in matrices and for fused bonds between fibers and matrices. Enables fabrication of composites of high specific strength and dimensional stability. Method particularly suitable for making low-thermal-expansion platforms for optical instruments.
Three-Dimensional Printing Surgical Applications.
AlAli, Ahmad B; Griffin, Michelle F; Butler, Peter E
2015-01-01
Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice.
Three dimensional reconnection in astrophysical plasmas
NASA Technical Reports Server (NTRS)
Spicer, D. S.
1990-01-01
Theoretical issues related to three-dimensional reconnection and its application to the space and astrophysical environment are reviewed. Consideration is given to the meaning of reconnection in three dimensions, the way in which periodic and nonperiodic magnetic topologies alter the physics of reconnections, and the effects of chaotic magnetic fields on the reconnection process.
[Three Dimensional Display in Nuclear Medicine].
Teraoka, Satomi; Souma, Tsutomu
2015-01-01
Imaging techniques to obtain a tomographic image in nuclear medicine such as PET and SPECT are widely used. It is necessary to interpreting all of the tomographic images obtained in order to accurately evaluate the individual lesion, whereas three dimensional display is often useful in order to overview and evaluate the feature of the entire lesion or disease such as the position, size and abnormal pattern. In Japan, the use of three dimensional image analysis workstation with an application of the co-registration and image fusion between the functional images such as PET or SPECT and anatomical images such as CT or MRI has been generalized. In addition, multimodality imaging system such as a PET/CT and SPECT/CT has been widespread. Therefore, it is expected to improve the diagnostic accuracy using three dimensionally image fusion to functional images with poor anatomical information. In this commentary, as an example of a three dimensional display that are commonly used in nuclear medicine examination in Japan, brain regions, cardiac region and bone and tumor region will be introduced separately.
Four-Dimensional Spatial Reasoning in Humans
ERIC Educational Resources Information Center
Aflalo, T. N.; Graziano, M. S. A.
2008-01-01
Human subjects practiced navigation in a virtual, computer-generated maze that contained 4 spatial dimensions rather than the usual 3. The subjects were able to learn the spatial geometry of the 4-dimensional maze as measured by their ability to perform path integration, a standard test of spatial ability. They were able to travel down a winding…
One-Dimensional Wavefront Sensor Analysis
Neal, Daniel R.
1996-04-25
This software analyzes one-dimensional wavefront sensor data acquired with any of several data acquisition systems. It analyzes the data to determine centroids, wavefront slopes and overall wavefront error. The data can be displayed in many formats, with plots of various parameters vs time and position, including computer generated movies. Data can also be exported for use by other programs.
Dimensional Tolerances: Back to the Basics
ERIC Educational Resources Information Center
Devine, K. L.
2012-01-01
Students often have difficulty grasping the principles of dimensional tolerances and frequently fail to recognize that dimensioning practice has a significant impact on the tolerance of part features. This observation may be attributed to several factors, not the least of which are changes in prior student education and life experiences and…
Valley excitons in two-dimensional semiconductors
Yu, Hongyi; Cui, Xiaodong; Xu, Xiaodong; ...
2014-12-30
Monolayer group-VIB transition metal dichalcogenides have recently emerged as a new class of semiconductors in the two-dimensional limit. The attractive properties include: the visible range direct band gap ideal for exploring optoelectronic applications; the intriguing physics associated with spin and valley pseudospin of carriers which implies potentials for novel electronics based on these internal degrees of freedom; the exceptionally strong Coulomb interaction due to the two-dimensional geometry and the large effective masses. The physics of excitons, the bound states of electrons and holes, has been one of the most actively studied topics on these two-dimensional semiconductors, where the excitons exhibitmore » remarkably new features due to the strong Coulomb binding, the valley degeneracy of the band edges, and the valley dependent optical selection rules for interband transitions. Here we give a brief overview of the experimental and theoretical findings on excitons in two-dimensional transition metal dichalcogenides, with focus on the novel properties associated with their valley degrees of freedom.« less
Two-Dimensional Turbulence in Magnetized Plasmas
ERIC Educational Resources Information Center
Kendl, A.
2008-01-01
In an inhomogeneous magnetized plasma the transport of energy and particles perpendicular to the magnetic field is in general mainly caused by quasi two-dimensional turbulent fluid mixing. The physics of turbulence and structure formation is of ubiquitous importance to every magnetically confined laboratory plasma for experimental or industrial…
Improving Perceptual Skills with 3-Dimensional Animations.
ERIC Educational Resources Information Center
Johns, Janet Faye; Brander, Julianne Marie
1998-01-01
Describes three-dimensional computer aided design (CAD) models for every component in a representative mechanical system; the CAD models made it easy to generate 3-D animations that are ideal for teaching perceptual skills in multimedia computer-based technical training. Fifteen illustrations are provided. (AEF)
Assessing Essential Dimensionality of Real Data
1992-08-05
The first ASSESSING ESSENTIAL DIMENSIONALITY-1O passage came from Of the Farm by John Updike . The second passage came from Light and Color in Nature...ff 2520 North Vernon Street 3..r.NJ 07102.1895 WasWsIngwt DC 203735000 Arlinglo. VA Z=27 r. Isaac I. Brjar Dr. John ML Coewell Dr. Leonard Feldt
Three Dimensional Display Of Meteorological Scientific Data
NASA Astrophysics Data System (ADS)
Grotch, Stanley L.
1988-01-01
Even a cursory reading of any daily newspaper shows that we are in the midst of a dramatic revolution in computer graphics. Virtually every day some new piece of hardware or software is announced, adding to the tools available to the working scientist. Three dimensional graphics form a significant part of this revolution having become virtually commonplace in advertising and on television.
Exploring the Dimensionality of Digit Span
ERIC Educational Resources Information Center
Bowden, Stephen C.; Petrauskas, Vilija M.; Bardenhagen, Fiona J.; Meade, Catherine E.; Simpson, Leonie C.
2013-01-01
The Digit Span subtest from the Wechsler Scales is used to measure Freedom from Distractibility or Working Memory. Some published research suggests that Digit Span forward should be interpreted differently from Digit Span backward. The present study explored the dimensionality of the Wechsler Memory Scale-III Digit Span (forward and backward)…
Valley excitons in two-dimensional semiconductors
Yu, Hongyi; Cui, Xiaodong; Xu, Xiaodong; Yao, Wang
2014-12-30
Monolayer group-VIB transition metal dichalcogenides have recently emerged as a new class of semiconductors in the two-dimensional limit. The attractive properties include: the visible range direct band gap ideal for exploring optoelectronic applications; the intriguing physics associated with spin and valley pseudospin of carriers which implies potentials for novel electronics based on these internal degrees of freedom; the exceptionally strong Coulomb interaction due to the two-dimensional geometry and the large effective masses. The physics of excitons, the bound states of electrons and holes, has been one of the most actively studied topics on these two-dimensional semiconductors, where the excitons exhibit remarkably new features due to the strong Coulomb binding, the valley degeneracy of the band edges, and the valley dependent optical selection rules for interband transitions. Here we give a brief overview of the experimental and theoretical findings on excitons in two-dimensional transition metal dichalcogenides, with focus on the novel properties associated with their valley degrees of freedom.
One-Dimensional Oscillator in a Box
ERIC Educational Resources Information Center
Amore, Paolo; Fernandez, Francisco M.
2010-01-01
We discuss a quantum-mechanical model of two particles that interact by means of a harmonic potential and are confined to a one-dimensional box with impenetrable walls. We apply perturbation theory to the cases of different and equal masses and analyse the symmetry of the states in the latter case. We compare the approximate perturbation results…
Three-dimensional colorimetric assay assemblies
Charych, Deborah; Reichert, Anke
2001-01-01
A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flue virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.
Three-Dimensional Pointers for Stereoscopic Projection.
ERIC Educational Resources Information Center
Hayman, H. J. G.
1984-01-01
Because class size often limits student opportunity to handle individual models, teachers use stereoscopic projections to demonstrate structural features. Describes three-dimensional pointers for use with different projection systems so teachers can indicate a particular atom or bond to entire classes, avoiding the perspective problems inherent in…
Two-Dimensional Turbulence in Magnetized Plasmas
ERIC Educational Resources Information Center
Kendl, A.
2008-01-01
In an inhomogeneous magnetized plasma the transport of energy and particles perpendicular to the magnetic field is in general mainly caused by quasi two-dimensional turbulent fluid mixing. The physics of turbulence and structure formation is of ubiquitous importance to every magnetically confined laboratory plasma for experimental or industrial…
Dimensionalism: The Missing Element in American Schooling.
ERIC Educational Resources Information Center
Rogers, Joseph A.
1986-01-01
Ascribes the basic flaw in American education to lack of dimensionalism, the sense of at-homeness in an ordered world and universe. Praises the Hellenic educators who inspired youth to self-confidence and suprahuman effort, in contrast to Salinger's hero Holden Caufield's feelings of alienation and self-doubt. Cites four references. (MLH)
[Dimensional modeling analysis for outpatient payments].
Guo, Yi-zhong; Guo, Yi-min
2008-09-01
This paper introduces a data warehouse model for outpatient payments, which is designed according to the requirements of the hospital financial management while dimensional modeling technique is combined with the analysis on the requirements. This data warehouse model can not only improve the accuracy of financial management requirements, but also greatly increase the efficiency and quality of the hospital management.
Splitting Enables Overcoming the Curse of Dimensionality
2015-12-01
repeat the entire iteration. Numerical experiments on an Intel Laptop Core i5-5300U running at 2.3 GHz are now presented. We consider diagonal...The convergence is remarkably rapid: 10−6 to 10−8 seconds on a standard laptop , per function evaluation. Figure 1 depicts 2-dimensional slices at
One-Dimensional Oscillator in a Box
ERIC Educational Resources Information Center
Amore, Paolo; Fernandez, Francisco M.
2010-01-01
We discuss a quantum-mechanical model of two particles that interact by means of a harmonic potential and are confined to a one-dimensional box with impenetrable walls. We apply perturbation theory to the cases of different and equal masses and analyse the symmetry of the states in the latter case. We compare the approximate perturbation results…
Vibroacoustics of three-dimensional drum silencer
NASA Astrophysics Data System (ADS)
Huang, Lixi; Choy, Y. S.
2005-10-01
When a segment of a rigid duct wall is replaced by a membrane and is backed by a cavity, incident noise induces membrane vibrations and causes noise reflection. The reflection is effective over a broad band in the low-frequency region when a certain high tension is applied on the membrane in the axial direction of the duct. The device is thus called a drumlike silencer. The existing vibroacoustic theory is based on a two-dimensional duct model and the membrane is reduced to a one-dimensional string. This study extends the theory to three dimensions for the duct and two dimensions for the membrane which has all four edges fixed. It is shown, analytically, that the lateral tension is always detrimental to the silencing performance. However, the optimal performance of the one-dimensional string is recovered exactly when the lateral tension on the two-dimensional membrane vanishes despite the very different boundary conditions. The conclusion is validated experimentally, paving the way for the application of the drum silencer in which the cavity is completely separated from the gas flow in the duct.
Dimensionally Stable Ether-Containing Polyimide Copolymers
NASA Technical Reports Server (NTRS)
Fay, Catharine C. (Inventor); St.Clair, Anne K. (Inventor)
1999-01-01
Novel polyimide copolymers containing ether linkages were prepared by the reaction of an equimolar amount of dianhydride and a combination of diamines. The polyimide copolymers described herein possess the unique features of low moisture uptake, dimensional stability, good mechanical properties, and moderate glass transition temperatures. These materials have potential application as encapsulants and interlayer dielectrics.
A Sim(2) invariant dimensional regularization
NASA Astrophysics Data System (ADS)
Alfaro, J.
2017-09-01
We introduce a Sim (2) invariant dimensional regularization of loop integrals. Then we can compute the one loop quantum corrections to the photon self energy, electron self energy and vertex in the Electrodynamics sector of the Very Special Relativity Standard Model (VSRSM).
One-dimensional differential Hardy inequality.
Kalybay, Aigerim
2017-01-01
We establish necessary and sufficient conditions for the one-dimensional differential Hardy inequality to hold, including the overdetermined case. The solution is given in terms different from those of the known results. Moreover, the least constant for this inequality is estimated.
Two-Dimensional Motions of Rockets
ERIC Educational Resources Information Center
Kang, Yoonhwan; Bae, Saebyok
2007-01-01
We analyse the two-dimensional motions of the rockets for various types of rocket thrusts, the air friction and the gravitation by using a suitable representation of the rocket equation and the numerical calculation. The slope shapes of the rocket trajectories are discussed for the three types of rocket engines. Unlike the projectile motions, the…
Growing Three-Dimensional Cocultures Of Cells
NASA Technical Reports Server (NTRS)
Wolf, David A.; Goodwin, Thomas J.
1995-01-01
Laboratory process provides environmental conditions favoring simultaneous growth of cocultures of mammalian cells of more than one type. Cultures become three-dimensional tissuelike assemblies serving as organoid models of differentiation of cells. Process used, for example, to study growth of human colon cancers, starting from mixtures of normal colonic fibroblasts and partially differentiated colon adenocarcinoma cells.
Three-dimensional implicit lambda methods
NASA Technical Reports Server (NTRS)
Napolitano, M.; Dadone, A.
1983-01-01
This paper derives the three dimensional lambda-formulation equations for a general orthogonal curvilinear coordinate system and provides various block-explicit and block-implicit methods for solving them, numerically. Three model problems, characterized by subsonic, supersonic and transonic flow conditions, are used to assess the reliability and compare the efficiency of the proposed methods.
Hypercontractivity in finite-dimensional matrix algebras
Junge, Marius; Palazuelos, Carlos
2015-02-15
We obtain hypercontractivity estimates for a large class of semigroups defined on finite-dimensional matrix algebras M{sub n}. These semigroups arise from Poisson-like length functions ψ on ℤ{sub n} × ℤ{sub n} and provide new hypercontractive families of quantum channels when ψ is conditionally negative. We also study the optimality of our estimates.
Water repellency and dimensional stability of wood
Roger M. Rowell; W. Bart Banks
1985-01-01
A discussion of the interaction between wood and water makes clear the distinction between water repellency of wood (a rate of change) and dimensional stability (a level of equilibrium). A review of methods of treating wood follows, leading to comparison of their effectiveness, description of test procedures to evaluate treatments, and discussion of deficiencies of the...
Three-Dimensional Visualization of Particle Tracks.
ERIC Educational Resources Information Center
Julian, Glenn M.
1993-01-01
Suggests ways to bring home to the introductory physics student some of the excitement of recent discoveries in particle physics. Describes particle detectors and encourages the use of the Standard Model along with real images of particle tracks to determine three-dimensional views of tracks. (MVL)
One-Dimensional Fluids with Positive Potentials
NASA Astrophysics Data System (ADS)
Fantoni, Riccardo
2017-03-01
We study a class of one-dimensional classical fluids with penetrable particles interacting through positive, purely repulsive, pair-potentials. Starting from some lower bounds to the total potential energy, we draw results on the thermodynamic limit of the given model.
Dimensional phase transition in small Yukawa clusters
Sheridan, T. E.; Wells, K. D.
2010-01-15
We investigate the one- to two-dimensional zigzag transition in clusters consisting of a small number of particles interacting through a Yukawa (Debye) potential and confined in a two-dimensional biharmonic potential well. Dusty (complex) plasma clusters with n<=19 monodisperse particles are characterized experimentally for two different confining wells. The well anisotropy is accurately measured, and the Debye shielding parameter is determined from the longitudinal breathing frequency. Debye shielding is shown to be important. A model for this system is used to predict equilibrium particle configurations. The experiment and model exhibit excellent agreement. The critical value of n for the zigzag transition is found to be less than that predicted for an unshielded Coulomb interaction. The zigzag transition is shown to behave as a continuous phase transition from a one-dimensional to a two-dimensional state, where the state variables are the number of particles, the well anisotropy and the Debye shielding parameter. A universal critical exponent for the zigzag transition is identified for transitions caused by varying the Debye shielding parameter.
Dimensional Tolerances: Back to the Basics
ERIC Educational Resources Information Center
Devine, K. L.
2012-01-01
Students often have difficulty grasping the principles of dimensional tolerances and frequently fail to recognize that dimensioning practice has a significant impact on the tolerance of part features. This observation may be attributed to several factors, not the least of which are changes in prior student education and life experiences and…
3-dimensional imaging at nanometer resolutions
Werner, James H.; Goodwin, Peter M.; Shreve, Andrew P.
2010-03-09
An apparatus and method for enabling precise, 3-dimensional, photoactivation localization microscopy (PALM) using selective, two-photon activation of fluorophores in a single z-slice of a sample in cooperation with time-gated imaging for reducing the background radiation from other image planes to levels suitable for single-molecule detection and spatial location, are described.
VLSI Unit for Two-Dimensional Convolutions
NASA Technical Reports Server (NTRS)
Liu, K. Y.
1983-01-01
Universal logic structure allows same VLSI chip to be used for variety of computational functions required for two dimensional convolutions. Fast polynomial transform technique is extended into tree computational structure composed of two units: fast polynomial transform (FPT) unit and Chinese remainder theorem (CRT) computational unit.
Three-Dimensional Printing Surgical Applications
Griffin, Michelle F.; Butler, Peter E.
2015-01-01
Introduction: Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. Objective: To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Methods: Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Discussion: Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Conclusion: Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice. PMID:26301002
Low-Dimensional Topological Crystalline Insulators.
Wang, Qisheng; Wang, Feng; Li, Jie; Wang, Zhenxing; Zhan, Xueying; He, Jun
2015-09-01
Topological crystalline insulators (TCIs) are recently discovered topological phase with robust surface states residing on high-symmetry crystal surfaces. Different from conventional topological insulators (TIs), protection of surface states on TCIs comes from point-group symmetry instead of time-reversal symmetry in TIs. The distinct properties of TCIs make them promising candidates for the use in novel spintronics, low-dissipation quantum computation, tunable pressure sensor, mid-infrared detector, and thermoelectric conversion. However, similar to the situation in TIs, the surface states are always suppressed by bulk carriers, impeding the exploitation of topology-induced quantum phenomenon. One effective way to solve this problem is to grow low-dimensional TCIs which possess large surface-to-volume ratio, and thus profoundly increase the carrier contribution from topological surface states. Indeed, through persistent effort, researchers have obtained unique quantum transport phenomenon, originating from topological surface states, based on controllable growth of low-dimensional TCIs. This article gives a comprehensive review on the recent progress of controllable synthesis and topological surface transport of low-dimensional TCIs. The possible future direction about low-dimensional TCIs is also briefly discussed at the end of this paper. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Orlita, M.; Faugeras, C.; Barra, A.-L.; Martinez, G.; Potemski, M.; Basko, D. M.; Teppe, F.; Knap, W.; Gavrilenko, V. I.; Mikhailov, N. N.; Dvoretskii, S. A.; Neugebauer, P.; Berger, C.
2015-03-21
Here, we report on a magneto-optical study of two distinct systems hosting massless fermions—two-dimensional graphene and three-dimensional HgCdTe tuned to the zero band gap condition at the point of the semiconductor-to-semimetal topological transition. Both materials exhibit, in the quantum regime, a fairly rich magneto-optical response, which is composed from a series of intra- and interband inter-Landau level resonances with for massless fermions typical √(B) dependence. The impact of the system's dimensionality and of the strength of the spin-orbit interaction on the optical response is also discussed.
The transition from three-dimensional to two-dimensional foam structures.
Jones, S A; Cox, S J
2011-08-01
A two-dimensional foam consists of a monolayer of bubbles. It can be created by squeezing the more familiar three-dimensional foam between two parallel glass plates. We describe and explain the minimum plate separation H which must be reached to fully effect the transition from three- to two- dimensional foam. We find that H/V(1/3) is close to one, where V is the average bubble volume, and increases slightly when the side-walls of the container are taken into account.
Wang, Zhen
2016-05-01
The purpose of this study was to evaluate two types of impression materials which were frequently used for casting three-dimensional tool marks in China, namely (i) dental impression material and (ii) special elastomeric impression material for tool mark casting. The two different elastomeric impression materials were compared under equal conditions. The parameters measured were dimensional accuracies, the number of air bubbles, the ease of use, and the sharpness and quality of the individual characteristics present on casts. The results showed that dental impression material had the advantage of special elastomeric impression material in casting tool marks in crime scenes; hence, it combined ease of use, dimensional accuracy, sharpness and high quality.
Trading spaces: building three-dimensional nets from two-dimensional tilings
Castle, Toen; Evans, Myfanwy E.; Hyde, Stephen T.; Ramsden, Stuart; Robins, Vanessa
2012-01-01
We construct some examples of finite and infinite crystalline three-dimensional nets derived from symmetric reticulations of homogeneous two-dimensional spaces: elliptic (S2), Euclidean (E2) and hyperbolic (H2) space. Those reticulations are edges and vertices of simple spherical, planar and hyperbolic tilings. We show that various projections of the simplest symmetric tilings of those spaces into three-dimensional Euclidean space lead to topologically and geometrically complex patterns, including multiple interwoven nets and tangled nets that are otherwise difficult to generate ab initio in three dimensions. PMID:24098839
NASA Astrophysics Data System (ADS)
Gu, Yingfei; Lee, Ching Hua; Wen, Xueda; Cho, Gil Young; Ryu, Shinsei; Qi, Xiao-Liang
2016-09-01
In this paper, we study (2 +1 ) -dimensional quantum anomalous Hall states, i.e., band insulators with quantized Hall conductance, using exact holographic mapping. Exact holographic mapping is an approach to holographic duality which maps the quantum anomalous Hall state to a different state living in (3 +1 ) -dimensional hyperbolic space. By studying topological response properties and the entanglement spectrum, we demonstrate that the holographic dual theory of a quantum anomalous Hall state is a (3 +1 ) -dimensional topological insulator. The dual description enables a characterization of topological properties of a system by the quantum entanglement between degrees of freedom at different length scales.
Metal Contacts on Low-Dimensional Materials
NASA Astrophysics Data System (ADS)
Yuan, Hui
As the scaling of the microelectronics is reaching nano regime, low-dimensional materials have been of increasing interest for future electronics applications. The low-dimensional materials, such as Si nanowires (SiNWs), carbon nanotubes (CNTs), graphene and transition metal dichalcogenides (TMDs), not only provide small body for further-scaled devices but also bring about new intrinsic properties for application in future optoelectronics, spintronics and so on. However, the small dimensions add significant difficulty for reducing contact resistance in the nanoelectronic devices. This dissertation presents a study of the metal contacts on low-dimensional materials. The focus of this work is on SiNWs and monolayer or few-layer MoS2. First, the metal contact on SiNW field effect transistors (FETs) was studied with a gate assisted Kelvin structure. In this work, I fabricated ambipolar SiNW FETs with Al contacts. The ambipolar characteristics and the gate assisted Kelvin structure enabled the measurement of the contact properties of both electron and hole flows at the same contact. In this work I found that the contact performance is affected by the carrier type that flows in the channel as well as the current direction. In addition, an inverter was designed and realized on a single SiNW leveraged by the ambipolar FET characteristics. Then, I have studied metal contacts on MoS2, which is one of typical two-dimensional semiconductors. In the first part of this work, Ag and Ti contacts on exfoliated MoS2 monolayers and few-layers are fabricated, characterized and analyzed. Based on the current-voltage (I-V) measurement, surface morphology and Raman spectroscopic measurement, I found that interface morphology plays an important role on the contact performance in MoS2 FETs. In the second part of this work, gate-assisted contact measurement was carried out on chemical vapor deposited low-dimensional MoS 2 layers. The contact resistance and current crowding have been
Thermodynamics of ultracold Bose gases at a dimensional crossover
NASA Astrophysics Data System (ADS)
Labouvie, Ralf; Vogler, Andreas; Guarrera, Vera; Ott, Herwig
2013-05-01
We have studied the thermodynamics of ultracold Bose gases in the crossover from a three-dimensional to a one-dimensional regime. In our experiment, we use a focused electron-beam to probe in situ atomic density distributions with high temporal and spatial resolution. Starting with a Bose-Einstein-Condensate in a single beam optical dipole trap we can create one-dimensional systems by loading the atoms in a two-dimensional blue-detuned optical lattice. With increasing strength of the lattices we go from a three-dimensional into a one-dimensional system. Furthermore we tune the interaction strengths of the one-dimensional quantum-gases from weak (quasi-condensate) to strong (Tonks-Girardeau). By measuring the density profiles and applying an inverse Abel-Transformation we extract the equation of states of these systems and characterize the crossover from the three-dimensional to the one-dimensional regime.
Mokbel, Nancy; Ilkovski, Biljana; Kreissl, Michaela; Memo, Massimiliano; Jeffries, Cy M; Marttila, Minttu; Lehtokari, Vilma-Lotta; Lemola, Elina; Grönholm, Mikaela; Yang, Nan; Menard, Dominique; Marcorelles, Pascale; Echaniz-Laguna, Andoni; Reimann, Jens; Vainzof, Mariz; Monnier, Nicole; Ravenscroft, Gianina; McNamara, Elyshia; Nowak, Kristen J; Laing, Nigel G; Wallgren-Pettersson, Carina; Trewhella, Jill; Marston, Steve; Ottenheijm, Coen; North, Kathryn N; Clarke, Nigel F
2013-02-01
Mutations in the TPM2 gene, which encodes β-tropomyosin, are an established cause of several congenital skeletal myopathies and distal arthrogryposis. We have identified a TPM2 mutation, p.K7del, in five unrelated families with nemaline myopathy and a consistent distinctive clinical phenotype. Patients develop large joint contractures during childhood, followed by slowly progressive skeletal muscle weakness during adulthood. The TPM2 p.K7del mutation results in the loss of a highly conserved lysine residue near the N-terminus of β-tropomyosin, which is predicted to disrupt head-to-tail polymerization of tropomyosin. Recombinant K7del-β-tropomyosin incorporates poorly into sarcomeres in C2C12 myotubes and has a reduced affinity for actin. Two-dimensional gel electrophoresis of patient muscle and primary patient cultured myotubes showed that mutant protein is expressed but incorporates poorly into sarcomeres and likely accumulates in nemaline rods. In vitro studies using recombinant K7del-β-tropomyosin and force measurements from single dissected patient myofibres showed increased myofilament calcium sensitivity. Together these data indicate that p.K7del is a common recurrent TPM2 mutation associated with mild nemaline myopathy. The p.K7del mutation likely disrupts head-to-tail polymerization of tropomyosin, which impairs incorporation into sarcomeres and also affects the equilibrium of the troponin/tropomyosin-dependent calcium switch of muscle. Joint contractures may stem from chronic muscle hypercontraction due to increased myofibrillar calcium sensitivity while declining strength in adulthood likely arises from other mechanisms, such as myofibre decompensation and fatty infiltration. These results suggest that patients may benefit from therapies that reduce skeletal muscle calcium sensitivity, and we highlight late muscle decompensation as an important cause of morbidity.
Numerical investigations in three-dimensional internal flows
NASA Technical Reports Server (NTRS)
Rose, William C.
1991-01-01
The present study is a preliminary investigation into the behavior of the flow within a 28 degree total geometric turning angle hypothetical Mach 10 inlet as calculated with the full three-dimensional Navier-Stokes equations. Comparison between the two-dimensional and three-dimensional solutions have been made. The overall compression is not significantly different between the two-dimensional and center plane three dimensional solutions. Approximately one-half to two-thirds of the inlet flow at the exit of the inlet behave nominally two-dimensionally. On the other hand, flow field non-uniformities in the three-dimensional solution indicate the potential significance of the sidewall boundary layer flows ingested into the inlet. The tailoring of the geometry at the inlet shoulder and on the cowl obtained in the two-dimensional parametric design study have also proved to be effective at controlling the boundary layer behavior in the three-dimensional code. The three-dimensional inlet solution remained started indicating that the two-dimensional design had a sufficient margin to allow for three-dimensional flow field effects. Although confidence is being gained in the use of SCRAM3D (three-dimensional full Navier-Stokes code) as applied to similar flow fields, the actual effects of the three-dimensional flow fields associated with sidewalls and wind tunnel installations can require verification with ground-based experiments.
Stimuli Reduce the Dimensionality of Cortical Activity.
Mazzucato, Luca; Fontanini, Alfredo; La Camera, Giancarlo
2016-01-01
The activity of ensembles of simultaneously recorded neurons can be represented as a set of points in the space of firing rates. Even though the dimension of this space is equal to the ensemble size, neural activity can be effectively localized on smaller subspaces. The dimensionality of the neural space is an important determinant of the computational tasks supported by the neural activity. Here, we investigate the dimensionality of neural ensembles from the sensory cortex of alert rats during periods of ongoing (inter-trial) and stimulus-evoked activity. We find that dimensionality grows linearly with ensemble size, and grows significantly faster during ongoing activity compared to evoked activity. We explain these results using a spiking network model based on a clustered architecture. The model captures the difference in growth rate between ongoing and evoked activity and predicts a characteristic scaling with ensemble size that could be tested in high-density multi-electrode recordings. Moreover, we present a simple theory that predicts the existence of an upper bound on dimensionality. This upper bound is inversely proportional to the amount of pair-wise correlations and, compared to a homogeneous network without clusters, it is larger by a factor equal to the number of clusters. The empirical estimation of such bounds depends on the number and duration of trials and is well predicted by the theory. Together, these results provide a framework to analyze neural dimensionality in alert animals, its behavior under stimulus presentation, and its theoretical dependence on ensemble size, number of clusters, and correlations in spiking network models.
Sonic morphology: Aesthetic dimensional auditory spatial awareness
NASA Astrophysics Data System (ADS)
Whitehouse, Martha M.
The sound and ceramic sculpture installation, " Skirting the Edge: Experiences in Sound & Form," is an integration of art and science demonstrating the concept of sonic morphology. "Sonic morphology" is herein defined as aesthetic three-dimensional auditory spatial awareness. The exhibition explicates my empirical phenomenal observations that sound has a three-dimensional form. Composed of ceramic sculptures that allude to different social and physical situations, coupled with sound compositions that enhance and create a three-dimensional auditory and visual aesthetic experience (see accompanying DVD), the exhibition supports the research question, "What is the relationship between sound and form?" Precisely how people aurally experience three-dimensional space involves an integration of spatial properties, auditory perception, individual history, and cultural mores. People also utilize environmental sound events as a guide in social situations and in remembering their personal history, as well as a guide in moving through space. Aesthetically, sound affects the fascination, meaning, and attention one has within a particular space. Sonic morphology brings art forms such as a movie, video, sound composition, and musical performance into the cognitive scope by generating meaning from the link between the visual and auditory senses. This research examined sonic morphology as an extension of musique concrete, sound as object, originating in Pierre Schaeffer's work in the 1940s. Pointing, as John Cage did, to the corporeal three-dimensional experience of "all sound," I composed works that took their total form only through the perceiver-participant's participation in the exhibition. While contemporary artist Alvin Lucier creates artworks that draw attention to making sound visible, "Skirting the Edge" engages the perceiver-participant visually and aurally, leading to recognition of sonic morphology.
Stimuli Reduce the Dimensionality of Cortical Activity
Mazzucato, Luca; Fontanini, Alfredo; La Camera, Giancarlo
2016-01-01
The activity of ensembles of simultaneously recorded neurons can be represented as a set of points in the space of firing rates. Even though the dimension of this space is equal to the ensemble size, neural activity can be effectively localized on smaller subspaces. The dimensionality of the neural space is an important determinant of the computational tasks supported by the neural activity. Here, we investigate the dimensionality of neural ensembles from the sensory cortex of alert rats during periods of ongoing (inter-trial) and stimulus-evoked activity. We find that dimensionality grows linearly with ensemble size, and grows significantly faster during ongoing activity compared to evoked activity. We explain these results using a spiking network model based on a clustered architecture. The model captures the difference in growth rate between ongoing and evoked activity and predicts a characteristic scaling with ensemble size that could be tested in high-density multi-electrode recordings. Moreover, we present a simple theory that predicts the existence of an upper bound on dimensionality. This upper bound is inversely proportional to the amount of pair-wise correlations and, compared to a homogeneous network without clusters, it is larger by a factor equal to the number of clusters. The empirical estimation of such bounds depends on the number and duration of trials and is well predicted by the theory. Together, these results provide a framework to analyze neural dimensionality in alert animals, its behavior under stimulus presentation, and its theoretical dependence on ensemble size, number of clusters, and correlations in spiking network models. PMID:26924968
Robust Nonnegative Patch Alignment for Dimensionality Reduction.
You, Xinge; Ou, Weihua; Chen, Chun Lung Philip; Li, Qiang; Zhu, Ziqi; Tang, Yuanyan
2015-11-01
Dimensionality reduction is an important method to analyze high-dimensional data and has many applications in pattern recognition and computer vision. In this paper, we propose a robust nonnegative patch alignment for dimensionality reduction, which includes a reconstruction error term and a whole alignment term. We use correntropy-induced metric to measure the reconstruction error, in which the weight is learned adaptively for each entry. For the whole alignment, we propose locality-preserving robust nonnegative patch alignment (LP-RNA) and sparsity-preserviing robust nonnegative patch alignment (SP-RNA), which are unsupervised and supervised, respectively. In the LP-RNA, we propose a locally sparse graph to encode the local geometric structure of the manifold embedded in high-dimensional space. In particular, we select large p -nearest neighbors for each sample, then obtain the sparse representation with respect to these neighbors. The sparse representation is used to build a graph, which simultaneously enjoys locality, sparseness, and robustness. In the SP-RNA, we simultaneously use local geometric structure and discriminative information, in which the sparse reconstruction coefficient is used to characterize the local geometric structure and weighted distance is used to measure the separability of different classes. For the induced nonconvex objective function, we formulate it into a weighted nonnegative matrix factorization based on half-quadratic optimization. We propose a multiplicative update rule to solve this function and show that the objective function converges to a local optimum. Several experimental results on synthetic and real data sets demonstrate that the learned representation is more discriminative and robust than most existing dimensionality reduction methods.
Grave, Frank; Buser, Michael
2008-01-01
Visualization of general relativity illustrates aspects of Einstein's insights into the curved nature of space and time to the expert as well as the layperson. One of the most interesting models which came up with Einstein's theory was developed by Kurt Gödel in 1949. The Gödel universe is a valid solution of Einstein's field equations, making it a possible physical description of our universe. It offers remarkable features like the existence of an optical horizon beyond which time travel is possible. Although we know that our universe is not a Gödel universe, it is interesting to visualize physical aspects of a world model resulting from a theory which is highly confirmed in scientific history. Standard techniques to adopt an egocentric point of view in a relativistic world model have shortcomings with respect to the time needed to render an image as well as difficulties in applying a direct illumination model. In this paper we want to face both issues to reduce the gap between common visualization standards and relativistic visualization. We will introduce two techniques to speed up recalculation of images by means of preprocessing and lookup tables and to increase image quality through a special optimization applicable to the Gödel universe. The first technique allows the physicist to understand the different effects of general relativity faster and better by generating images from existing datasets interactively. By using the intrinsic symmetries of Gödel's spacetime which are expressed by the Killing vector field, we are able to reduce the necessary calculations to simple cases using the second technique. This even makes it feasible to account for a direct illumination model during the rendering process. Although the presented methods are applied to Gödel's universe, they can also be extended to other manifolds, for example light propagation in moving dielectric media. Therefore, other areas of research can benefit from these generic improvements.
Calidad de Imagen del Telescopio UNAM212
NASA Astrophysics Data System (ADS)
Cobos, F. J.; Teiada de Vargas, C.
1987-05-01
El telescopio UNAM2l2, del Observatorio Astronómico Nacional, situado en la Sierra de San Pedro Mártir (Baja California, México), cumplira en un futuro muy cercano siete años de uso para fines de investigación astronómica. Aunque en este tiempo no se ha efectuado un estudio sistemático acerca de su comportamiento óptico y de los factores que influyen en la calidad de las imágenes, se han realizado pruebas diversas, estudios parciales y reuniones especificas, cuyos resultados no siempre se han difundido ampliamente y generalmente no se han presentado por escrito. Es por ello que hemos creido necesario intentar una recopilación de la información existente para poder con ella establecer un diagnóstjco que, aunque no sea definitivo, sirva de base para futuros trabajos tendientes a optimizar el comportamiento óptico del telescopio. Es evidente que un buen número de las conclusiones que se presentan son resultado del trabajo de muchas personas ó de esfuerzos colectivos. Asimismo, hemos tratado de localizar información bibliográfica que pueda ser de utilidad. Nuestro objetivo primordial ha consistido en centrarnos en la óptica del telescopio y su calidad, pero también se han considerado otros aspectos que puedan afectar las imágenes obtenidas tales como: celda del primario, `seeing' local y externo, flexiones posibles en la estructura mecánica del telescopio, etc.
Radio-Observaciones del OH EN la Coma del Cometa Halley Desde EL Hemisferio Sur
NASA Astrophysics Data System (ADS)
Silva, A. M.; Bajaja, E.; Morras, R.; Cersosimo, J. C.; Martin, M. C.; Arnal, E. M.; Poppel, W. G. L.; Colomb, F. R.; Mazzaro, J.; Olalde, J. C.; Boriakoff, V.; Mirabel, I. F.
1987-05-01
Se utilizó una antena de 30 metros del Instituto Argentino de Radioastronomía para observaciones diarias Cf ebrero a abril de 1986) de la transición en 1667 MHz ( λ = 18 cm) del OH en la coma del cometa Halley. De las observaciones realizadas se concluye: 1) El número promedio de moléculas de OH en la coma durante 37 días de observación fue de (8.9±3.5)x1034 moléculas, lo que implica una tasa de producción promedio de OH de 1.8x1029 moléculas seg-1 y consecuentemente una pérdida de masa promedio de 17±6 toneladas seg-1 . Este valor está de acuerdo con las mediciones realizadas por las sondas Vega y Giotto. 2) El monitoreo desde el lAR revela la existencia de variaciones bruscas en los flujos de absorción del OH. Estas variaciones son consistentes con los modelos que representan la producción gaseosa a partir de ejecciones y/o desprendimientos discretos de materia congelada del núcleo. 3) Las variaciones en la densidad de flujo son consistentes con las estimaciones de los tiem- pos de vida medios del H2O y del OH en presencia del campo de radiación solar. 4) Se encuentra una correlación entre la intensidad del flujo absorbido y anisotropías en Ia dinamica de la coma.
[Revista de Gastroenterologia del Peru: 25 years].
Celestino Fernández, Alvaro
2005-01-01
In this article is described in a very summarized form the history of the Revista de Gastroenterología del Perú (RGP) that dates from the same origins of the Sociedad de Gastroenterología del Perú, when based in October 30 of 1952 already glimpse the presence of the RGP as the official organ for the publication for studies of doctors of the society or foreign guests. We spent 29 years, and this idea becomes reality; and today the RGP turns to their XXV anniversary. The RGP, to locate itself as the Peruvian medical publication best reputation.
McChesney, P.J.
1999-01-01
El McVCO es un generador de frecuencias basado en un microcontrolador que reemplaza al oscilador controlado por voltaje (VCO) utilizado en telemetría analógica de datos sísmicas. Acepta señales de baja potencia desde un sismómetro y produce una señal subportadora modulada en frecuencia adecuada para enlaces telefónicos o vía radio a un lugar remoto de recolección de datos. La frecuencia de la subportadora y la ganancia pueden ser seleccionadas mediante un interruptor. Tiene la opción de poder operar con dos canales para la observación con ganancia alta y baja. El McVCO fue diseñado con el propósito de mejorar la telemetría analógica de las señales dentro de la Pacific Northwest Seismograph Network (PNSN) (Red Sismográfica del Noroeste del Pacífico). Su desarrollo recibió el respaldo del Programa de Geofísica de la Universidad de Washington y del "Volcano Hazards and Earthquake Hazards programs of the United States Geological Survey (USGS) (Programa de Investigaciones de Riesgos Volcánicos y Programa de Investigaciones de Riesgos Sísmicos de los EEUU). Cientos de instrumentos se han construido e instalado. Además de utilizarlo el PNSN, el McVCO es usado por el Observatorio Vulcanológico de Alaska para monitorear los volcanes aleutianos y por el USGS Volcano Disaster Assistance Program (Programa de Ayuda en las Catástrofes Volcánicas del USGS) para responder a crisis volcánicas en otros países. Este manual cubre el funcionamiento del McVCO, es una referencia técnica para aquellos que necesitan saber con más detalle cómo funciona el McVCO, y cubre una serie de temas que requieren un trato explícito o que derivan del despliegue del instrumento.
A Shell Multi-dimensional Hierarchical Cubing Approach for High-Dimensional Cube
NASA Astrophysics Data System (ADS)
Zou, Shuzhi; Zhao, Li; Hu, Kongfa
The pre-computation of data cubes is critical for improving the response time of OLAP systems and accelerating data mining tasks in large data warehouses. However, as the sizes of data warehouses grow, the time it takes to perform this pre-computation becomes a significant performance bottleneck. In a high dimensional data warehouse, it might not be practical to build all these cuboids and their indices. In this paper, we propose a shell multi-dimensional hierarchical cubing algorithm, based on an extension of the previous minimal cubing approach. This method partitions the high dimensional data cube into low multi-dimensional hierarchical cube. Experimental results show that the proposed method is significantly more efficient than other existing cubing methods.
Filling of three-dimensional space by two-dimensional sheet growth
NASA Astrophysics Data System (ADS)
Etzold, Merlin A.; McDonald, Peter J.; Faux, David A.; Routh, Alexander F.
2015-10-01
Models of three-dimensional space filling based on growth of two-dimensional sheets are proposed. Beginning from planar Eden-style growth of sheets, additional growth modes are introduced. These enable the sheets to form layered or disordered structures. The growth modes can also be combined. An off-lattice kinetic Monte Carlo-based computer algorithm is presented and used to study the kinetics of the new models and the resulting structures. It is possible to study space filling by two-dimensional growth in a three-dimensional domain with arbitrarily oriented sheets; the results agree with previously published models where the sheets are only able to grow in a limited set of directions. The introduction of a bifurcation mechanism gives rise to complex disordered structures that are of interest as model structures for the mesostructure of calcium silicate hydrate in hardened cement paste.
Three-Dimensional Frame Buffers For Interactive Analysis Of Three-Dimensional Data
NASA Astrophysics Data System (ADS)
Hunter, Gregory M.
1986-02-01
Two-dimensional data such as photos, x-rays, various types of satellite images, sonar, radar, seismic plots, etc., in many cases must be analyzed using frame buffers for purposes of medical diagnoses, crop estimates, mineral exploration, and so forth. In many cases the same types of sensors used to gather such samples in two dimensions can gather 3D data for even more effective analysis. Just as 2D arrays of data can be analyzed using frame buffers, three-dimensional data can be analyzed using SOLIDS-BUFFER memories. Image processors deal with samples from two-dimensional arrays and are based on frame buffers. The SOLIDS PROCESSOR system deals with samples from a three-dimensional volume, or solid, and is based on a 3D frame buffer. This paper focuses upon the SOLIDS-BUFFER system as used in the INSIGHT SOLIDS-PROCESSOR system from Phoenix Data Systems.
Two-Dimensional Versus Three-Dimensional Conceptualization in Astronomy Education
NASA Astrophysics Data System (ADS)
Reynolds, Michael David
Numerous science conceptual issues are naturally three-dimensional. Classroom presentations are often two -dimensional or at best multidimensional. Several astronomy topics are of this nature, e. g. mechanics of the phases of the moon. Textbooks present this three-dimensional topic in two-dimensions; such is often the case in the classroom. This study was conducted to examine conceptions exhibited by pairs of like-sex 11th grade standard physics students as they modeled the lunar phases. Student pairs, 13 male and 13 female, were randomly selected and assigned. Pairing comes closer to classroom emulation, minimizes needs for direct probes, and pair discussion is more likely to display variety and depth. Four hypotheses were addressed: (1) Participants who model three-dimensionally will more likely achieve a higher explanation score. (2) Students who experienced more earth or physical science exposure will more likely model three-dimensionally. (3) Pairs that exhibit a strong science or mathematics preference will more likely model three-dimensionally. (4) Males will model in three dimensions more than females. Students provided background information, including science course exposure and subject preference. Each pair laid out a 16-card set representing two complete lunar phase changes. The pair was asked to explain why the phases occur. Materials were provided for use, including disks, spheres, paper and pen, and flashlight. Activities were videotaped for later evaluation. Statistics of choice was a correlation determination between course preference and model type and ANOVA for the other hypotheses. It was determined that pairs who modeled three -dimensionally achieved a higher score on their phases mechanics explanation at p <.05 level. Pairs with earth science or physical science exposure, those who prefer science or mathematics, and male participants were not more likely to model three-dimensionally. Possible reasons for lack of significance was small sample
Baño Piñero, Isabel; Canteras Jordana, Manuel; Carrillo García, Cesar; López Araez, Alicia; Martínez Roche, María Emilia
2015-04-01
Antecedentes: partimos de la hipótesis de que no existen suficientes cuestionarios validados que midan el impacto de las redes de apoyo a la lactancia materna para población hispano hablante. Objetivo: Por ese motivo, nos planteamos como objetivo general de este trabajo, elaborar y validar (a nivel de contenido y constructo) un instrumento de medida cuantitativa. Método: Se evaluó la validez de contenido sometiendo el cuestionario a un juicio de expertos en lactancia materna de la Región de Murcia. La prueba piloto se llevó a cabo entre los meses de marzo y abril de 2014. Las encuestas fueron realizadas directamente por las usuarias que acudían al grupo de apoyo a la lactancia “Lactando”. Para la validez de constructo se realizó un análisis factorial con el que se determinaron las distintas dimensiones que el cuestionario podría medir. Se realizó una estadística descriptiva de cada uno de los ítems. A través del análisis de componentes principales, se obtuvo la varianza total explicada, determinando así, los factores con los elementos que los definían. Resultados: A través del análisis factorial, el cuestionario obtuvo una alta consistencia interna para sus cinco componentes (satisfacción, consultas, experiencia, problemas y apoyo), consiguiendo valores de 0,942 a 0,632. Y un porcentaje de varianza total explicada elevado (11,157% - 5,093%). Conclusión: Este estudio ha servido para crear un instrumento pertinente y válido a nivel de contenido y de constructo, capaz de medir el impacto de las redes de apoyo a la lactancia a través de 5 dimensiones.
NASA Technical Reports Server (NTRS)
Misiakos, K.; Lindholm, F. A.
1986-01-01
Several parameters of certain three-dimensional semiconductor devices including diodes, transistors, and solar cells can be determined without solving the actual boundary-value problem. The recombination current, transit time, and open-circuit voltage of planar diodes are emphasized here. The resulting analytical expressions enable determination of the surface recombination velocity of shallow planar diodes. The method involves introducing corresponding one-dimensional models having the same values of these parameters.
NASA Astrophysics Data System (ADS)
Chen, L. X.; Wu, Q. P.
2012-10-01
Recently, Dada et al. reported on the experimental entanglement concentration and violation of generalized Bell inequalities with orbital angular momentum (OAM) [Nat. Phys. 7, 677 (2011)]. Here we demonstrate that the high-dimensional entanglement concentration can be performed in arbitrary OAM subspaces with selectivity. Instead of violating the generalized Bell inequalities, the working principle of present entanglement concentration is visualized by the biphoton OAM Klyshko picture, and its good performance is confirmed and quantified through the experimental Shannon dimensionalities after concentration.
Hirata, Yoshito; Aihara, Kazuyuki
2012-06-01
We introduce a low-dimensional description for a high-dimensional system, which is a piecewise affine model whose state space is divided by permutations. We show that the proposed model tends to predict wind speeds and photovoltaic outputs for the time scales from seconds to 100 s better than by global affine models. In addition, computations using the piecewise affine model are much faster than those of usual nonlinear models such as radial basis function models.
Validating two-dimensional leadership models on three-dimensionally structured fish schools.
Watts, Isobel; Nagy, Máté; Holbrook, Robert I; Biro, Dora; Burt de Perera, Theresa
2017-01-01
Identifying leader-follower interactions is crucial for understanding how a group decides where or when to move, and how this information is transferred between members. Although many animal groups have a three-dimensional structure, previous studies investigating leader-follower interactions have often ignored vertical information. This raises the question of whether commonly used two-dimensional leader-follower analyses can be used justifiably on groups that interact in three dimensions. To address this, we quantified the individual movements of banded tetra fish (Astyanax mexicanus) within shoals by computing the three-dimensional trajectories of all individuals using a stereo-camera technique. We used these data firstly to identify and compare leader-follower interactions in two and three dimensions, and secondly to analyse leadership with respect to an individual's spatial position in three dimensions. We show that for 95% of all pairwise interactions leadership identified through two-dimensional analysis matches that identified through three-dimensional analysis, and we reveal that fish attend to the same shoalmates for vertical information as they do for horizontal information. Our results therefore highlight that three-dimensional analyses are not always required to identify leader-follower relationships in species that move freely in three dimensions. We discuss our results in terms of the importance of taking species' sensory capacities into account when studying interaction networks within groups.
Laser one-dimensional range profile and the laser two-dimensional range profile of cylinders
NASA Astrophysics Data System (ADS)
Gong, Yanjun; Wang, Mingjun; Gong, Lei
2015-10-01
Laser one-dimensional range profile, that is scattering power from pulse laser scattering of target, is a radar imaging technology. The laser two-dimensional range profile is two-dimensional scattering imaging of pulse laser of target. Laser one-dimensional range profile and laser two-dimensional range profile are called laser range profile(LRP). The laser range profile can reflect the characteristics of the target shape and surface material. These techniques were motivated by applications of laser radar to target discrimination in ballistic missile defense. The radar equation of pulse laser is given in this paper. This paper demonstrates the analytical model of laser range profile of cylinder based on the radar equation of the pulse laser. Simulations results of laser one-dimensional range profiles of some cylinders are given. Laser range profiles of cylinder, whose surface material with diffuse lambertian reflectance, is given in this paper. Laser range profiles of different pulse width of cylinder are given in this paper. The influences of geometric parameters, pulse width, attitude on the range profiles are analyzed.
A sparse grid based method for generative dimensionality reduction of high-dimensional data
NASA Astrophysics Data System (ADS)
Bohn, Bastian; Garcke, Jochen; Griebel, Michael
2016-03-01
Generative dimensionality reduction methods play an important role in machine learning applications because they construct an explicit mapping from a low-dimensional space to the high-dimensional data space. We discuss a general framework to describe generative dimensionality reduction methods, where the main focus lies on a regularized principal manifold learning variant. Since most generative dimensionality reduction algorithms exploit the representer theorem for reproducing kernel Hilbert spaces, their computational costs grow at least quadratically in the number n of data. Instead, we introduce a grid-based discretization approach which automatically scales just linearly in n. To circumvent the curse of dimensionality of full tensor product grids, we use the concept of sparse grids. Furthermore, in real-world applications, some embedding directions are usually more important than others and it is reasonable to refine the underlying discretization space only in these directions. To this end, we employ a dimension-adaptive algorithm which is based on the ANOVA (analysis of variance) decomposition of a function. In particular, the reconstruction error is used to measure the quality of an embedding. As an application, the study of large simulation data from an engineering application in the automotive industry (car crash simulation) is performed.
Validating two-dimensional leadership models on three-dimensionally structured fish schools
Nagy, Máté; Holbrook, Robert I.; Biro, Dora; Burt de Perera, Theresa
2017-01-01
Identifying leader–follower interactions is crucial for understanding how a group decides where or when to move, and how this information is transferred between members. Although many animal groups have a three-dimensional structure, previous studies investigating leader–follower interactions have often ignored vertical information. This raises the question of whether commonly used two-dimensional leader–follower analyses can be used justifiably on groups that interact in three dimensions. To address this, we quantified the individual movements of banded tetra fish (Astyanax mexicanus) within shoals by computing the three-dimensional trajectories of all individuals using a stereo-camera technique. We used these data firstly to identify and compare leader–follower interactions in two and three dimensions, and secondly to analyse leadership with respect to an individual's spatial position in three dimensions. We show that for 95% of all pairwise interactions leadership identified through two-dimensional analysis matches that identified through three-dimensional analysis, and we reveal that fish attend to the same shoalmates for vertical information as they do for horizontal information. Our results therefore highlight that three-dimensional analyses are not always required to identify leader–follower relationships in species that move freely in three dimensions. We discuss our results in terms of the importance of taking species' sensory capacities into account when studying interaction networks within groups. PMID:28280582
The usefulness of 3-dimensional endoscope systems in endoscopic surgery.
Egi, Hiroyuki; Hattori, Minoru; Suzuki, Takahisa; Sawada, Hiroyuki; Kurita, Yuichi; Ohdan, Hideki
2016-10-01
The image quality and performance of 3-dimensional video image systems has improved along with improvements in technology. However, objective evaluation on the usefulness of 3-dimensional video image systems is insufficient. Therefore, we decided to investigate the usefulness of 3-dimensional video image systems using the objective endoscopic surgery technology evaluating apparatus that we have developed, the Hiroshima University Endoscopic Surgical Assessment Device (HUESAD). The participants were 28 student volunteers enrolled in Hiroshima University (17 men and 11 women, age: median 22.5, range 20-25), with no one having experienced endoscopic surgery training. Testing was carried out by dividing the subjects into two groups to initially carry out HUESAD with 2-dimensional video imaging (N = 14) and with 3-dimensional video imaging (N = 14). Questionnaires were carried out along with the investigation regarding both 2-dimensional and 3-dimensional video imaging. The task was carried out for approximately 15 min regarding both 2-dimensional and 3-dimensional video imaging. Lastly, the Mental Rotation Test, which is a standard space perception ability test, was used to evaluate the space perception ability. No difference was observed in the nauseous and uncomfortable feeling of practitioners between the two groups. Regarding smoothness, no difference was observed between 2-dimensional and 3-dimensional video imaging (p = 0.8665). Deviation (space perception ability) and approaching time (accuracy) were significantly lower with 3-dimensional video imaging compared to 2-dimensional video imaging. Moreover, the approaching time (accuracy) significantly improved in 3-dimensional video imaging compared to 2-dimensional video imaging in the group with low space perception ability (p = 0.0085). Objective evaluation using HUESAD and subjective evaluation by questionnaire revealed that endoscopic surgery techniques significantly improved in 3-dimensional video
Magnetization study of two dimensional helium three
NASA Astrophysics Data System (ADS)
Guo, Lei
This dissertation discusses a magnetization study of a two dimensional Fermi system. Our group developed a SQUID NMR system to study the magnetization of two dimensional 3He on both GTA grafoil and ZYX Graphite substrates. Benefiting from SQUID technology, our NMR experiments were performed at very low applied magnetic field thus avoid the masking of ordering by strong external field. Monolayer 3He films adsorbed on crystalline graphite are considered a nearly ideal example of a two dimensional system of highly correlated fermions. By controlling the 3He areal density, adsorbed films exhibit a wide range of structures with different temperature- dependent magnetic properties and heat capacities. Our recent experiments on two dimensional 3He adsorbed on ZYX graphite focused on the anti-ferromagnetic 4/7 phase and the ferromagnetic incommensurate solid state of a second 3He monolayer. Ferromagnetic order was observed in two dimensional 3He films on both Grafoil and highly oriented ZYX grade exfoliated graphite. The dipolar field plays an important role in magnetic ordering in two dimensional spin systems. The dipole-dipole interaction leads to a frequency shift of the NMR absorption line. The resulting 3He NMR lineshape on Grafoil was a broad peak shifted towards lower frequency with a background from the randomly oriented regions extending to positive frequencies. Compared to Grafoil, ZYX graphite has a much greater structural coherence and is more highly oriented. When studying magnetism of 3He films on ZYX substrate we found that the features we observed in our original Grafoil experiment were much more pronounced on ZYX graphite. In addition, we observed some multi-peak structure on the 3He NMR lineshape, which suggest a series of spin wave resonances. We also studied the magnetic properties of the second layer of 3He films on ZYX substrate at density around 4/7 phase. To eliminate the paramagnetic signal of the first layer solid, we pre-plated a 4He layer on the
33 CFR 80.1118 - Marina Del Rey, CA.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Marina Del Rey, CA. 80.1118 Section 80.1118 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1118 Marina Del Rey, CA. (a) A line drawn from Marina Del Rey Breakwater South Light...
Comunidades de la Cuenca Baja del Río Merrimack
Lista de todas las comunidades que se incluyen en los límites 8, 10 y 12 del código de unidades hidrológicas (HUC) para la cuenca del río Merrimack y las ubicaciones de la ciudad de las estaciones de control de calidad del agua de la EPA.
Dimensionality of object representations in monkey inferotemporal cortex.
Lehky, Sidney R; Kiani, Roozbeh; Esteky, Hossein; Tanaka, Keiji
2014-10-01
We have calculated the intrinsic dimensionality of visual object representations in anterior inferotemporal (AIT) cortex, based on responses of a large sample of cells stimulated with photographs of diverse objects. Because dimensionality was dependent on data set size, we determined asymptotic dimensionality as both the number of neurons and number of stimulus image approached infinity. Our final dimensionality estimate was 93 (SD: ± 11), indicating that there is basis set of approximately 100 independent features that characterize the dimensions of neural object space. We believe this is the first estimate of the dimensionality of neural visual representations based on single-cell neurophysiological data. The dimensionality of AIT object representations was much lower than the dimensionality of the stimuli. We suggest that there may be a gradual reduction in the dimensionality of object representations in neural populations going from retina to inferotemporal cortex as receptive fields become increasingly complex.
Dimensionality of object representations in monkey inferotemporal cortex
Lehky, Sidney R.; Kiani, Roozbeh; Esteky, Hossein; Tanaka, Keiji
2014-01-01
We have calculated the intrinsic dimensionality of visual object representations in anterior inferotemporal (AIT) cortex, based on responses of a large sample of cells stimulated with photographs of diverse objects. As dimensionality was dependent on data set size, we determined asymptotic dimensionality as both the number of neurons and number of stimulus image approached infinity. Our final dimensionality estimate was 93 (SD: ± 11), indicating that there is basis set of approximately a hundred independent features that characterize the dimensions of neural object space. We believe this is the first estimate of the dimensionality of neural visual representations based on single-cell neurophysiological data. The dimensionality of AIT object representations was much lower than the dimensionality of the stimuli. We suggest that there may be a gradual reduction in the dimensionality of object representations in neural populations going from retina to inferotemporal cortex, as receptive fields become increasingly complex. PMID:25058707
FPT Algorithm for Two-Dimensional Cyclic Convolutions
NASA Technical Reports Server (NTRS)
Truong, Trieu-Kie; Shao, Howard M.; Pei, D. Y.; Reed, Irving S.
1987-01-01
Fast-polynomial-transform (FPT) algorithm computes two-dimensional cyclic convolution of two-dimensional arrays of complex numbers. New algorithm uses cyclic polynomial convolutions of same length. Algorithm regular, modular, and expandable.
Thermodynamics of higher dimensional black holes
Accetta, F.S.; Gleiser, M.
1986-05-01
We discuss the thermodynamics of higher dimensional black holes with particular emphasis on a new class of spinning black holes which, due to the increased number of Casimir invariants, have additional spin degrees of freedom. In suitable limits, analytic solutions in arbitrary dimensions are presented for their temperature, entropy, and specific heat. In 5 + 1 and 9 + 1 dimensions, more general forms for these quantities are given. It is shown that the specific heat for a higher dimensional black hole is negative definite if it has only one non-zero spin parameter, regardless of the value of this parameter. We also consider equilibrium configurations with both massless particles and massive string modes. 16 refs., 3 figs.
Kirigami for Two-Dimensional Electronic Membranes
NASA Astrophysics Data System (ADS)
Qi, Zenan; Bahamon, Dario; Campbell, David; Park, Harold
2015-03-01
Two-dimensional materials have recently drawn tremendous attention because of their unique properties. In this work, we introduce the notion of two-dimensional kirigami, where concepts that have been used almost exclusively for macroscale structures are applied to dramatically enhance their stretchability. Specifically, we show using classical molecular dynamics simulations that the yield and fracture strains of graphene and MoS2 can be enhanced by about a factor of three using kirigami as compared to standard monolayers. Finally, using graphene as an example, we demonstrate that the kirigami structure may open up interesting opportunities in coupling to the electronic behavior of 2D materials. Authors acknowledge Mechanical Engineering and Physics departments at Boston University, and Mackgrafe at Mackenzie Presbyterian University.
Two-dimensional ranking of Wikipedia articles
NASA Astrophysics Data System (ADS)
Zhirov, A. O.; Zhirov, O. V.; Shepelyansky, D. L.
2010-10-01
The Library of Babel, described by Jorge Luis Borges, stores an enormous amount of information. The Library exists ab aeterno. Wikipedia, a free online encyclopaedia, becomes a modern analogue of such a Library. Information retrieval and ranking of Wikipedia articles become the challenge of modern society. While PageRank highlights very well known nodes with many ingoing links, CheiRank highlights very communicative nodes with many outgoing links. In this way the ranking becomes two-dimensional. Using CheiRank and PageRank we analyze the properties of two-dimensional ranking of all Wikipedia English articles and show that it gives their reliable classification with rich and nontrivial features. Detailed studies are done for countries, universities, personalities, physicists, chess players, Dow-Jones companies and other categories.
Vortices in Low-Dimensional Magnetic Systems
NASA Astrophysics Data System (ADS)
Costa, B. V.
2011-05-01
Vortices are objects that are important to describe several physical phenomena. There are many examples of such objects in nature as in a large variety of physical situations like in fluid dynamics, superconductivity, magnetism, and biology. Historically, the interest in magnetic vortex-like excitations begun in the 1960s. That interest was mainly associated with an unusual phase-transition phenomenon in two-dimensional magnetic systems. More recently, direct experimental evidence for the existence of magnetic vortex states in nano-disks was found. The interest in such model was renewed due to the possibility of the use of magnetic nano-disks as bit elements in nano-scale memory devices. The goal of this study is to review some key points for the understanding of the vortex behavior and the progress that have been done in the study of vortices in low-dimensional magnetic systems.
Three Dimensional Particle Tracking in Superfluid Helium
NASA Astrophysics Data System (ADS)
Megson, Peter
2016-11-01
Superfluid helium is a macroscopic quantum state which exhibits exotic physical properties, such as flow without friction and ballistic heat transport. Superfluid flow is irrotational except about line-like topological phase defects with quantized circulation, known as quatized vortices. The presence of these vortices and their dynamics is the dominating factor of turbulence in superfluid flows. One commonly studied regime of superfluid turbulence is thermal counterflow, where a local heat flux drives the formation and growth of a tangle of vortices. This talk will present experimental studies of counterflow turbulence performed using a multi-camera three-dimensional imaging apparatus with micron-sized ice tracer particles as well as fluorescent nanoparticles. In particular, we will discuss the measurement of three-dimensional velocties and their autocorrelations. Additionally, we are developing new techniques for optical studies of bulk superfluid helium, with particular focus on characterizing tracer particles and particle dispersal mechanisms. Funding from NSF DMR-1407472.
Three-dimensional trabecular alignment model.
Bono, Eric S; Smolinski, Patrick; Casagranda, Al; Xu, Junde
2003-04-01
Trabecular alignment theory has been used to quantify Wolff's Law of bone remodeling. A three-dimensional finite element scheme was developed to analyze the bone remodeling phenomenon. The mathematical model proposed by Mullender et al. and later modified by Smith et al. was adopted to simulate the surface-based trabecular resorption and formation processes. Enhancements incorporated into the previous model include: mapping into three-dimensions, controlling the remodeling signal's passage through marrow, controlling the finite distance the signal may pass through the bone matrix, and including non-bone material in the finite element model. After the model is explained and thoroughly studied, three-dimensional implant surface geometries are simulated.
A two-dimensional Dirac fermion microscope
NASA Astrophysics Data System (ADS)
Bøggild, Peter; Caridad, José M.; Stampfer, Christoph; Calogero, Gaetano; Papior, Nick Rübner; Brandbyge, Mads
2017-06-01
The electron microscope has been a powerful, highly versatile workhorse in the fields of material and surface science, micro and nanotechnology, biology and geology, for nearly 80 years. The advent of two-dimensional materials opens new possibilities for realizing an analogy to electron microscopy in the solid state. Here we provide a perspective view on how a two-dimensional (2D) Dirac fermion-based microscope can be realistically implemented and operated, using graphene as a vacuum chamber for ballistic electrons. We use semiclassical simulations to propose concrete architectures and design rules of 2D electron guns, deflectors, tunable lenses and various detectors. The simulations show how simple objects can be imaged with well-controlled and collimated in-plane beams consisting of relativistic charge carriers. Finally, we discuss the potential of such microscopes for investigating edges, terminations and defects, as well as interfaces, including external nanoscale structures such as adsorbed molecules, nanoparticles or quantum dots.
Extended inflation from higher dimensional theories
NASA Technical Reports Server (NTRS)
Holman, Richard; Kolb, Edward W.; Vadas, Sharon L.; Wang, Yun
1990-01-01
The possibility is considered that higher dimensional theories may, upon reduction to four dimensions, allow extended inflation to occur. Two separate models are analayzed. One is a very simple toy model consisting of higher dimensional gravity coupled to a scalar field whose potential allows for a first-order phase transition. The other is a more sophisticated model incorporating the effects of non-trivial field configurations (monopole, Casimir, and fermion bilinear condensate effects) that yield a non-trivial potential for the radius of the internal space. It was found that extended inflation does not occur in these models. It was also found that the bubble nucleation rate in these theories is time dependent unlike the case in the original version of extended inflation.
Quantum transport in d-dimensional lattices
Manzano, Daniel; Chuang, Chern; Cao, Jianshu
2016-04-28
We show that both fermionic and bosonic uniform d-dimensional lattices can be reduced to a set of independent one-dimensional chains. This reduction leads to the expression for ballistic energy fluxes in uniform fermionic and bosonic lattices. By the use of the Jordan–Wigner transformation we can extend our analysis to spin lattices, proving the coexistence of both ballistic and non-ballistic subspaces in any dimension and for any system size. Lastly, we then relate the nature of transport to the number of excitations in the homogeneous spin lattice, indicating that a single excitation always propagates ballistically and that the non-ballistic behaviour ofmore » uniform spin lattices is a consequence of the interaction between different excitations.« less
Analysis of three-dimensional transonic compressors
NASA Technical Reports Server (NTRS)
Bourgeade, A.
1984-01-01
A method for computing the three-dimensional transonic flow around the blades of a compressor or of a propeller is given. The method is based on the use of the velocity potential, on the hypothesis that the flow is inviscid, irrotational and isentropic. The equation of the potential is solved in a transformed space such that the surface of the blade is mapped into a plane where the periodicity is implicit. This equation is in a nonconservative form and is solved with the help of a finite difference method using artificial time. A computer code is provided and some sample results are given in order to demonstrate the influence of three-dimensional effects and the blade's rotation.
Two-dimensional optimal sensor placement
Zhang, H.
1995-05-01
A method for determining the optimal two-dimensional spatial placement of multiple sensors participating in a robot perception task is introduced in this paper. This work is motivated by the fact that sensor data fusion is an effective means of reducing uncertainties in sensor observations, and that the combined uncertainty varies with the relative placement of the sensors with respect to each other. The problem of optimal sensor placement is formulated and a solution is presented in the two dimensional space. The algebraic structure of the combined sensor uncertainty with respect to the placement of sensor is studied. A necessary condition for optimal placement is derived and this necessary condition is used to obtain an efficient closed-form solution for the global optimal placement. Numerical examples are provided to illustrate the effectiveness and efficiency of the solution. 11 refs.
Rainich conditions in (2 + 1)-dimensional gravity
NASA Astrophysics Data System (ADS)
Krongos, D. S.; Torre, C. G.
2017-01-01
In (3 + 1) spacetime dimensions, the Rainich conditions are a set of equations expressed solely in terms of the metric tensor which are equivalent to the Einstein-Maxwell equations for non-null electromagnetic fields. Here we provide the analogous conditions for (2 + 1)-dimensional gravity coupled to electromagnetism. Both the non-null and null cases are treated. The construction of these conditions is based upon reducing the problem to that of gravity coupled to a scalar field, which we have treated elsewhere. These conditions can be easily extended to other theories of (2 + 1)-dimensional gravity. For example, we apply the geometrization conditions to topologically massive gravity coupled to the electromagnetic field and obtain a family of plane-fronted wave solutions.
Electronics based on two-dimensional materials.
Fiori, Gianluca; Bonaccorso, Francesco; Iannaccone, Giuseppe; Palacios, Tomás; Neumaier, Daniel; Seabaugh, Alan; Banerjee, Sanjay K; Colombo, Luigi
2014-10-01
The compelling demand for higher performance and lower power consumption in electronic systems is the main driving force of the electronics industry's quest for devices and/or architectures based on new materials. Here, we provide a review of electronic devices based on two-dimensional materials, outlining their potential as a technological option beyond scaled complementary metal-oxide-semiconductor switches. We focus on the performance limits and advantages of these materials and associated technologies, when exploited for both digital and analog applications, focusing on the main figures of merit needed to meet industry requirements. We also discuss the use of two-dimensional materials as an enabling factor for flexible electronics and provide our perspectives on future developments.
A two-dimensional Dirac fermion microscope
Bøggild, Peter; Caridad, José M.; Stampfer, Christoph; Calogero, Gaetano; Papior, Nick Rübner; Brandbyge, Mads
2017-01-01
The electron microscope has been a powerful, highly versatile workhorse in the fields of material and surface science, micro and nanotechnology, biology and geology, for nearly 80 years. The advent of two-dimensional materials opens new possibilities for realizing an analogy to electron microscopy in the solid state. Here we provide a perspective view on how a two-dimensional (2D) Dirac fermion-based microscope can be realistically implemented and operated, using graphene as a vacuum chamber for ballistic electrons. We use semiclassical simulations to propose concrete architectures and design rules of 2D electron guns, deflectors, tunable lenses and various detectors. The simulations show how simple objects can be imaged with well-controlled and collimated in-plane beams consisting of relativistic charge carriers. Finally, we discuss the potential of such microscopes for investigating edges, terminations and defects, as well as interfaces, including external nanoscale structures such as adsorbed molecules, nanoparticles or quantum dots. PMID:28598421
A two-dimensional Dirac fermion microscope.
Bøggild, Peter; Caridad, José M; Stampfer, Christoph; Calogero, Gaetano; Papior, Nick Rübner; Brandbyge, Mads
2017-06-09
The electron microscope has been a powerful, highly versatile workhorse in the fields of material and surface science, micro and nanotechnology, biology and geology, for nearly 80 years. The advent of two-dimensional materials opens new possibilities for realizing an analogy to electron microscopy in the solid state. Here we provide a perspective view on how a two-dimensional (2D) Dirac fermion-based microscope can be realistically implemented and operated, using graphene as a vacuum chamber for ballistic electrons. We use semiclassical simulations to propose concrete architectures and design rules of 2D electron guns, deflectors, tunable lenses and various detectors. The simulations show how simple objects can be imaged with well-controlled and collimated in-plane beams consisting of relativistic charge carriers. Finally, we discuss the potential of such microscopes for investigating edges, terminations and defects, as well as interfaces, including external nanoscale structures such as adsorbed molecules, nanoparticles or quantum dots.
Toward two-dimensional search engines
NASA Astrophysics Data System (ADS)
Ermann, L.; Chepelianskii, A. D.; Shepelyansky, D. L.
2012-07-01
We study the statistical properties of various directed networks using ranking of their nodes based on the dominant vectors of the Google matrix known as PageRank and CheiRank. On average PageRank orders nodes proportionally to a number of ingoing links, while CheiRank orders nodes proportionally to a number of outgoing links. In this way, the ranking of nodes becomes two dimensional which paves the way for the development of two-dimensional search engines of a new type. Statistical properties of information flow on the PageRank-CheiRank plane are analyzed for networks of British, French and Italian universities, Wikipedia, Linux Kernel, gene regulation and other networks. A special emphasis is done for British universities networks using the large database publicly available in the UK. Methods of spam links control are also analyzed.
Two-dimensional lattice liquid models
NASA Astrophysics Data System (ADS)
Ishimoto, Yukitaka; Murashima, Takahiro; Taniguchi, Takashi; Yamamoto, Ryoichi
2012-09-01
A family of models of liquid on a two-dimensional lattice (2D lattice liquid models) have been proposed as primitive models of soft-material membrane. As a first step, we have formulated them as single-component, single-layered, classical particle systems on a two-dimensional surface with no explicit viscosity. Among the family of the models, we have shown and constructed two stochastic models, a vicious walk model and a flow model, on an isotropic regular lattice and on some honeycomb lattices of various sizes. In both cases, the dynamics is governed by the nature of the frustration of the particle movements. By simulations, we have found the approximate functional form of the frustration probability and peculiar anomalous diffusions in their time-averaged mean-square displacements in the flow model. The relations to other existing statistical models and possible extensions of the models are also discussed.
Two-dimensional fourier transform spectrometer
DeFlores, Lauren; Tokmakoff, Andrei
2016-10-25
The present invention relates to a system and methods for acquiring two-dimensional Fourier transform (2D FT) spectra. Overlap of a collinear pulse pair and probe induce a molecular response which is collected by spectral dispersion of the signal modulated probe beam. Simultaneous collection of the molecular response, pulse timing and characteristics permit real time phasing and rapid acquisition of spectra. Full spectra are acquired as a function of pulse pair timings and numerically transformed to achieve the full frequency-frequency spectrum. This method demonstrates the ability to acquire information on molecular dynamics, couplings and structure in a simple apparatus. Multi-dimensional methods can be used for diagnostic and analytical measurements in the biological, biomedical, and chemical fields.
Two-dimensional fourier transform spectrometer
DeFlores, Lauren; Tokmakoff, Andrei
2013-09-03
The present invention relates to a system and methods for acquiring two-dimensional Fourier transform (2D FT) spectra. Overlap of a collinear pulse pair and probe induce a molecular response which is collected by spectral dispersion of the signal modulated probe beam. Simultaneous collection of the molecular response, pulse timing and characteristics permit real time phasing and rapid acquisition of spectra. Full spectra are acquired as a function of pulse pair timings and numerically transformed to achieve the full frequency-frequency spectrum. This method demonstrates the ability to acquire information on molecular dynamics, couplings and structure in a simple apparatus. Multi-dimensional methods can be used for diagnostic and analytical measurements in the biological, biomedical, and chemical fields.
One-dimensional spinon spin currents
NASA Astrophysics Data System (ADS)
Hirobe, Daichi; Sato, Masahiro; Kawamata, Takayuki; Shiomi, Yuki; Uchida, Ken-Ichi; Iguchi, Ryo; Koike, Yoji; Maekawa, Sadamichi; Saitoh, Eiji
2017-01-01
Quantum spin fluctuation in a low-dimensional or frustrated magnet breaks magnetic ordering while keeping spin correlation. Such fluctuation has been a central topic in magnetism because of its relevance to high-Tc superconductivity and topological states. However, utilizing such spin states has been quite difficult. In a one-dimensional spin-1/2 chain, a particle-like excitation called a spinon is known to be responsible for spin fluctuation in a paramagnetic state. Spinons behave as a Tomonaga-Luttinger liquid at low energy, and the spin system is often called a quantum spin chain. Here we show that a quantum spin chain generates and carries spin current, which is attributed to spinon spin current. This is demonstrated by observing an anisotropic negative spin Seebeck effect along the spin chains in Sr2CuO3. The results show that spin current can flow even in an atomic channel owing to long-range spin fluctuation.
Cooperative two-dimensional directed transport
NASA Astrophysics Data System (ADS)
Zheng, Zhigang; Chen, Hongbin
2010-11-01
A mechanism for the cooperative directed transport in two-dimensional ratchet potentials is proposed. With the aid of mutual couplings among particles, coordinated unidirectional motion along the ratchet direction can be achieved by transforming the energy from the transversal rocking force (periodic or stochastic) to the work in the longitude direction. Analytical predictions on the relation between the current and other parameters for the ac-driven cases are given, which are in good agreement with numerical simulations. Stochastic driving forces can give rise to the resonant directional transport. The effect of the free length, which has been explored in experiments on the motility of bipedal molecular motors, is investigated for both the single- and double-channel cases. The mechanism and results proposed in this letter may both shed light on the collective locomotion of molecular motors and open ways on studies in two-dimensional collaborative ratchet dynamics.
Three dimensional digital imaging of environmental data
Nichols, R.L.; Eddy, C.A.
1991-06-14
The Environmental Sciences Section (ESS) of the Savannah River Laboratory has recently acquired the computer hardware (Silicon Graphics Personal Iris Workstations) and software (Dynamic Graphics, Interactive Surface and Volume Modeling) to perform three dimensional analysis of hydrogeologic data. Three dimensional digital imaging of environmental data is a powerful technique that can be used to incorporate field, analytical, and modeling results from geologic, hydrologic, ecologic, and chemical studies into a comprehensive model for visualization and interpretation. This report covers the contamination of four different sites of the Savannah River Plant. Each section of this report has a computer graphic display of the concentration of contamination in the groundwater and/or sediments of each site.
Energy dependent 4-dimensional multiple scattering distributions
NASA Astrophysics Data System (ADS)
Tschalär, C.
1984-12-01
A complete analytic solution in Fourier space is presented of the four dimensional small angle, multiple scattering distribution MSD in angle and space, produced by an energy dependent single scattering cross section from an initial pencil beam of heavy particles. Independently, simple integrals are derived for the central moments of the energy dependent MSD in the continuous-slowing-down approximation. The distributions of the projections t and x of the scattering angle and displacement into a plane through the axis of propagation are evaluated numerically for a truncated Rutherford scattering cross section using a fast Fourier transform. The resulting MSDs for a wide range of particles, initial and final momenta, and scattering materials are found to be approximately represented by one-dimensional set of standard distributions symmetrized by a linear transformation in t- x-space.
Three-Dimensional Reconstruction Of Ultrasound Images
NASA Astrophysics Data System (ADS)
Lalouche, Robert C.; Bickmore, Dan; Tessler, Franklin N.; Mankovich, Nicholas J.; Huang, H. K.; Kangarloo, Hooshang
1989-05-01
We have established a three-dimensional (3-D) imaging facility for reconstruction of serial two-dimensional (2-D) ultrasound images. In the facility, contiguous 2-D images are captured directly at the clinical site from the real-time video signals of a Labsonics serial ultrasound imager. The images are digitized and stored on an IBM PC. They are then transferred over an Ethernet communication network to the Image Processing Laboratory. Finally, the serial images are reformatted and the 3-D images are reconstructed on a Pixar image computer. The reconstruction method involves grey level remapping, slice interpolation, tissue classification, surface enhancement, illumination, projection, and display. We have demonstrated that 3-D ultra-sound images can be created which bring out features difficult to discern in 2-D ultrasound images.
Reflection and transmission at dimensional boundaries
De Leon, Nelson; Morris, John R.
2006-08-15
An inhomogeneous Kaluza-Klein compactification of a higher dimensional spacetime may give rise to an effective 4D spacetime with distinct domains having different sizes of the extra dimensions. The domains are separated by domain walls generated by the extra dimensional scale factor. The scattering of electromagnetic and massive particle waves at such boundaries is examined here for models without warping or branes. We consider the limits corresponding to thin (thick) domain walls, i.e., limits where wavelengths are large (small) in comparison to wall thickness. We also obtain numerical solutions for a wall of arbitrary thickness and extract the reflection and transmission coefficients as functions of frequency. Results are obtained which qualitatively resemble those for electroweak domain walls and other ordinary domain walls for 4D theories.
Real time three dimensional sensing system
Gordon, Steven J.
1996-01-01
The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane.
Real time three dimensional sensing system
Gordon, S.J.
1996-12-31
The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane. 7 figs.
Intrinsic two-dimensional features as textons
NASA Technical Reports Server (NTRS)
Barth, E.; Zetzsche, C.; Rentschler, I.
1998-01-01
We suggest that intrinsic two-dimensional (i2D) features, computationally defined as the outputs of nonlinear operators that model the activity of end-stopped neurons, play a role in preattentive texture discrimination. We first show that for discriminable textures with identical power spectra the predictions of traditional models depend on the type of nonlinearity and fail for energy measures. We then argue that the concept of intrinsic dimensionality, and the existence of end-stopped neurons, can help us to understand the role of the nonlinearities. Furthermore, we show examples in which models without strong i2D selectivity fail to predict the correct ranking order of perceptual segregation. Our arguments regarding the importance of i2D features resemble the arguments of Julesz and co-workers regarding textons such as terminators and crossings. However, we provide a computational framework that identifies textons with the outputs of nonlinear operators that are selective to i2D features.
Tunneling in two-dimensional QCD
NASA Astrophysics Data System (ADS)
Olesen, Poul
2006-09-01
The spectral density for two-dimensional continuum QCD has a non-analytic behavior for a critical area. Apparently this is not reflected in the Wilson loops. However, we show that the existence of a critical area is encoded in the winding Wilson loops: Although there is no non-analyticity or phase transition in these Wilson loops, the dynamics of these loops consists of two smoothly connected domains separated by the critical area, one domain with a confining behavior for large winding Wilson loops, and one (below the critical size) where the string tension disappears. We show that this can be interpreted in terms of a simple tunneling process between an ordered and a disordered state. In view of recent results by Narayanan and Neuberger this tunneling may also be relevant for four-dimensional QCD.
One-Dimensional Photonic Crystal Superprisms
NASA Technical Reports Server (NTRS)
Ting, David
2005-01-01
Theoretical calculations indicate that it should be possible for one-dimensional (1D) photonic crystals (see figure) to exhibit giant dispersions known as the superprism effect. Previously, three-dimensional (3D) photonic crystal superprisms have demonstrated strong wavelength dispersion - about 500 times that of conventional prisms and diffraction gratings. Unlike diffraction gratings, superprisms do not exhibit zero-order transmission or higher-order diffraction, thereby eliminating cross-talk problems. However, the fabrication of these 3D photonic crystals requires complex electron-beam substrate patterning and multilayer thin-film sputtering processes. The proposed 1D superprism is much simpler in structural complexity and, therefore, easier to design and fabricate. Like their 3D counterparts, the 1D superprisms can exhibit giant dispersions over small spectral bands that can be tailored by judicious structure design and tuned by varying incident beam direction. Potential applications include miniature gas-sensing devices.
Bootstrapping the Three Dimensional Supersymmetric Ising Model.
Bobev, Nikolay; El-Showk, Sheer; Mazáč, Dalimil; Paulos, Miguel F
2015-07-31
We implement the conformal bootstrap program for three dimensional conformal field theories with N=2 supersymmetry and find universal constraints on the spectrum of operator dimensions in these theories. By studying the bounds on the dimension of the first scalar appearing in the operator product expansion of a chiral and an antichiral primary, we find a kink at the expected location of the critical three dimensional N=2 Wess-Zumino model, which can be thought of as a supersymmetric analog of the critical Ising model. Focusing on this kink, we determine, to high accuracy, the low-lying spectrum of operator dimensions of the theory, as well as the stress-tensor two-point function. We find that the latter is in an excellent agreement with an exact computation.
Phonon hydrodynamics in two-dimensional materials.
Cepellotti, Andrea; Fugallo, Giorgia; Paulatto, Lorenzo; Lazzeri, Michele; Mauri, Francesco; Marzari, Nicola
2015-03-06
The conduction of heat in two dimensions displays a wealth of fascinating phenomena of key relevance to the scientific understanding and technological applications of graphene and related materials. Here, we use density-functional perturbation theory and an exact, variational solution of the Boltzmann transport equation to study fully from first-principles phonon transport and heat conductivity in graphene, boron nitride, molybdenum disulphide and the functionalized derivatives graphane and fluorographene. In all these materials, and at variance with typical three-dimensional solids, normal processes keep dominating over Umklapp scattering well-above cryogenic conditions, extending to room temperature and more. As a result, novel regimes emerge, with Poiseuille and Ziman hydrodynamics, hitherto typically confined to ultra-low temperatures, characterizing transport at ordinary conditions. Most remarkably, several of these two-dimensional materials admit wave-like heat diffusion, with second sound present at room temperature and above in graphene, boron nitride and graphane.
Social phobia: further evidence of dimensional structure.
Crome, Erica; Baillie, Andrew; Slade, Tim; Ruscio, Ayelet Meron
2010-11-01
Social phobia is a common mental disorder associated with significant impairment. Current research and treatment models of social phobia rely on categorical diagnostic conceptualizations lacking empirical support. This study aims to further research exploring whether social phobia is best conceptualized as a dimension or a discrete categorical disorder. This study used three distinct taxometric techniques (mean above minus below a cut, maximum Eigen value and latent mode) to explore the latent structure of social phobia in two large epidemiological samples, using indicators derived from diagnostic criteria and associated avoidant personality traits. Overall, outcomes from multiple taxometric analyses supported dimensional structure. This is consistent with conceptualizations of social phobia as lying on a continuum with avoidant personality traits. Support for the dimensionality of social phobia has important implications for future research, assessment, treatment, and public policy.
Enhancing genomics information retrieval through dimensional analysis.
Hu, Qinmin; Huang, Jimmy Xiangji
2013-06-01
We propose a novel dimensional analysis approach to employing meta information in order to find the relationships within the unstructured or semi-structured document/passages for improving genomics information retrieval performance. First, we make use of the auxiliary information as three basic dimensions, namely "temporal", "journal", and "author". The reference section is treated as a commensurable quantity of the three basic dimensions. Then, the sample space and subspaces are built up and a set of events are defined to meet the basic requirement of dimensional homogeneity to be commensurable quantities. After that, the classic graph analysis algorithm in the Web environments is applied on each dimension respectively to calculate the importance of each dimension. Finally, we integrate all the dimension networks and re-rank the outputs for evaluation. Our experimental results show the proposed approach is superior and promising.
Phonon hydrodynamics in two-dimensional materials
NASA Astrophysics Data System (ADS)
Cepellotti, Andrea; Fugallo, Giorgia; Paulatto, Lorenzo; Lazzeri, Michele; Mauri, Francesco; Marzari, Nicola
2015-03-01
The conduction of heat in two dimensions displays a wealth of fascinating phenomena of key relevance to the scientific understanding and technological applications of graphene and related materials. Here, we use density-functional perturbation theory and an exact, variational solution of the Boltzmann transport equation to study fully from first-principles phonon transport and heat conductivity in graphene, boron nitride, molybdenum disulphide and the functionalized derivatives graphane and fluorographene. In all these materials, and at variance with typical three-dimensional solids, normal processes keep dominating over Umklapp scattering well-above cryogenic conditions, extending to room temperature and more. As a result, novel regimes emerge, with Poiseuille and Ziman hydrodynamics, hitherto typically confined to ultra-low temperatures, characterizing transport at ordinary conditions. Most remarkably, several of these two-dimensional materials admit wave-like heat diffusion, with second sound present at room temperature and above in graphene, boron nitride and graphane.
Four-dimensional spatial reasoning in humans.
Aflalo, T N; Graziano, M S A
2008-10-01
Human subjects practiced navigation in a virtual, computer-generated maze that contained 4 spatial dimensions rather than the usual 3. The subjects were able to learn the spatial geometry of the 4-dimensional maze as measured by their ability to perform path integration, a standard test of spatial ability. They were able to travel down a winding corridor to its end and then point back accurately toward the occluded origin. One interpretation is that the brain substrate for spatial navigation is not a built-in map of the 3-dimensional world. Instead it may be better described as a set of general rules for manipulating spatial information that can be applied with practice to a diversity of spatial frameworks.
Simulation of complex three-dimensional flows
NASA Technical Reports Server (NTRS)
Diewert, G. S.; Rothmund, H. J.; Nakahashi, K.
1985-01-01
The concept of splitting is used extensively to simulate complex three dimensional flows on modern computer architectures. Used in all aspects, from initial grid generation to the determination of the final converged solution, splitting is used to enhance code vectorization, to permit solution driven grid adaption and grid enrichment, to permit the use of concurrent processing, and to enhance data flow through hierarchal memory systems. Three examples are used to illustrate these concepts to complex three dimensional flow fields: (1) interactive flow over a bump; (2) supersonic flow past a blunt based conical afterbody at incidence to a free stream and containing a centered propulsive jet; and (3) supersonic flow past a sharp leading edge delta wing at incidence to the free stream.
Transient One-dimensional Pipe Flow Analyzer
1986-04-08
TOPAZ-SNLL, the Transient One- dimensional Pipe flow AnalyZer code, is a user-friendly computer program for modeling the heat transfer, fluid mechanics, and thermodynamics of multi-species gas transfer in arbitrary arrangements of pipes, valves, vessels, and flow branches. Although the flow conservation equations are assumed to be one-dimensional and transient, multidimensional features of internal fluid flow and heat transfer may be accounted for using the available quasi-steady flow correlations (e.g., Moody friction factor correlation and various form loss and heat transfer correlations). Users may also model the effects of moving system boundaries such as pistons, diaphragms, and bladders. The features of fully compressible flow are modeled, including the propagation of shocks and rarefaction waves, as well as the establishment of multiple choke points along the flow path.
Three dimensional contact/impact methodology
Kulak, R.F.
1987-01-01
The simulation of three-dimensional interface mechanics between reactor components and structures during static contact or dynamic impact is necessary to realistically evaluate their structural integrity to off-normal loads. In our studies of postulated core energy release events, we have found that significant structure-structure interactions occur in some reactor vessel head closure designs and that fluid-structure interactions occur within the reactor vessel. Other examples in which three-dimensional interface mechanics play an important role are: (1) impact response of shipping casks containing spent fuel, (2) whipping pipe impact on reinforced concrete panels or pipe-to-pipe impact after a pipe break, (3) aircraft crash on secondary containment structures, (4) missiles generated by turbine failures or tornados, and (5) drops of heavy components due to lifting accidents. The above is a partial list of reactor safety problems that require adequate treatment of interface mechanics and are discussed in this paper.
Three-dimensional bio-printing.
Gu, Qi; Hao, Jie; Lu, YangJie; Wang, Liu; Wallace, Gordon G; Zhou, Qi
2015-05-01
Three-dimensional (3D) printing technology has been widely used in various manufacturing operations including automotive, defence and space industries. 3D printing has the advantages of personalization, flexibility and high resolution, and is therefore becoming increasingly visible in the high-tech fields. Three-dimensional bio-printing technology also holds promise for future use in medical applications. At present 3D bio-printing is mainly used for simulating and reconstructing some hard tissues or for preparing drug-delivery systems in the medical area. The fabrication of 3D structures with living cells and bioactive moieties spatially distributed throughout will be realisable. Fabrication of complex tissues and organs is still at the exploratory stage. This review summarize the development of 3D bio-printing and its potential in medical applications, as well as discussing the current challenges faced by 3D bio-printing.
Three-Dimensional Reflectance Traction Microscopy
Jones, Christopher A. R.; Groves, Nicholas Scott; Sun, Bo
2016-01-01
Cells in three-dimensional (3D) environments exhibit very different biochemical and biophysical phenotypes compared to the behavior of cells in two-dimensional (2D) environments. As an important biomechanical measurement, 2D traction force microscopy can not be directly extended into 3D cases. In order to quantitatively characterize the contraction field, we have developed 3D reflectance traction microscopy which combines confocal reflection imaging and partial volume correlation postprocessing. We have measured the deformation field of collagen gel under controlled mechanical stress. We have also characterized the deformation field generated by invasive breast cancer cells of different morphologies in 3D collagen matrix. In contrast to employ dispersed tracing particles or fluorescently-tagged matrix proteins, our methods provide a label-free, computationally effective strategy to study the cell mechanics in native 3D extracellular matrix. PMID:27304456
Intrinsic two-dimensional features as textons
NASA Technical Reports Server (NTRS)
Barth, E.; Zetzsche, C.; Rentschler, I.
1998-01-01
We suggest that intrinsic two-dimensional (i2D) features, computationally defined as the outputs of nonlinear operators that model the activity of end-stopped neurons, play a role in preattentive texture discrimination. We first show that for discriminable textures with identical power spectra the predictions of traditional models depend on the type of nonlinearity and fail for energy measures. We then argue that the concept of intrinsic dimensionality, and the existence of end-stopped neurons, can help us to understand the role of the nonlinearities. Furthermore, we show examples in which models without strong i2D selectivity fail to predict the correct ranking order of perceptual segregation. Our arguments regarding the importance of i2D features resemble the arguments of Julesz and co-workers regarding textons such as terminators and crossings. However, we provide a computational framework that identifies textons with the outputs of nonlinear operators that are selective to i2D features.
Lurry, Dee L.; Reutter, David C.; Wells, Frank C.; Rivera, M.C.; Munoz, A.
1998-01-01
La Oficina del Estudio Geologico de los Estados Unidos (U.S. Geological Survey, 0 USGS) ha monitoreado la calidad del agua de la cuenca del Rio Grande (Rio Bravo del Norte) desde 1995 como parte de la rediseiiada Red Nacional para Contabilizar la Calidad del Agua de los Rios (National Stream Quality Accounting Network, o NASOAN) (Hooper and others, 1997). EI programa NASOAN fue diseiiado para caracterizar las concentraciones y el transporte de sedimento y constituyentes quimicos seleccionados, encontrados en los grandes rios de los Estados Unidos - incluyendo el Misisipi, el Colorado y el Columbia, ademas del Rio Grande. En estas cuatro cuencas, el USGS opera actualmente (1998) una red de 40 puntos de muestreo pertenecientes a NASOAN, con un enfasis en cuantificar el flujo en masa (la cantidad de material que pasa por la estacion, expresado en toneladas por dial para cada constituyente. Aplicacando un enfoque consistente, basado en la cuantificacion de flujos en la cuenca del Rio Grande, el programa NASOAN esta generando la informacion necesaria para identificar fuentes regionales de diversos contaminantes, incluyendo sustancias qui micas agricolas y trazas elementos en la cuenca. EI efecto de las grandes reservas en el Rio Grande se puede observar segun los flujos de constituyentes discurren a 10 largo del rio. EI analisis de los flujos de constituyentes a escala de la cuenca proveera los medios para evaluar la influencia de la actividad humana sobre las condiciones de calidad del agua del Rio Grande.
Del Mod System. 1972 Annual Report.
ERIC Educational Resources Information Center
Purnell, Charlotte H.
The overall aim of the Del Mod System is the improvement of science programs taught in Delaware schools; it is a working agreement among the University of Delaware, Delaware Technical and Community College, Delaware State College, State Department of Public Instruction, industry, and the schools. It was formed to bring about changes in science…
Hopeful (protein InDel) monsters?
Tóth-Petróczy, Agnes; Tawfik, Dan S
2014-06-10
In this issue of Structure, Arpino and colleagues describe in atomic detail how a protein stomachs a deletion within a helix, an event that rarely occurs in nature or in the lab. Can insertions and deletions (InDels) trigger dramatic structural transitions? Copyright © 2014 Elsevier Ltd. All rights reserved.
Clustering, Dimensionality Reduction, and Side Information
2006-01-01
Tom, Timothy, Anthony, Twinsen, Dennis , Josie, Mitzi, Melody, Karen, Esther, Janni, Bean, Lok, Christal, Janice, and many more, has helped me to...types of outdoor images: brickface, sky, foliage, cement, window, path, and grass. The texture data set (texture) consists of 4000 19-dimensional Gabor ...different types of textures. The 19 features are based on Gabor filter responses. The four classes are of sizes 987, 999, 1027, and 987. The online
DIMENSIONALLY STABLE, CORROSION RESISTANT NUCLEAR FUEL
Kittel, J.H.
1963-10-31
A method of making a uranium alloy of improved corrosion resistance and dimensional stability is described. The alloy contains from 0-9 weight per cent of an additive of zirconium and niobium in the proportions by weight of 5 to 1 1/ 2. The alloy is cold rolled, heated to two different temperatures, air-cooled, heated to a third temperature, and quenched in water. (AEC)
Visual Exploration of High Dimensional Scalar Functions
Gerber, Samuel; Bremer, Peer-Timo; Pascucci, Valerio; Whitaker, Ross
2011-01-01
An important goal of scientific data analysis is to understand the behavior of a system or process based on a sample of the system. In many instances it is possible to observe both input parameters and system outputs, and characterize the system as a high-dimensional function. Such data sets arise, for instance, in large numerical simulations, as energy landscapes in optimization problems, or in the analysis of image data relating to biological or medical parameters. This paper proposes an approach to analyze and visualizing such data sets. The proposed method combines topological and geometric techniques to provide interactive visualizations of discretely sampled high-dimensional scalar fields. The method relies on a segmentation of the parameter space using an approximate Morse-Smale complex on the cloud of point samples. For each crystal of the Morse-Smale complex, a regression of the system parameters with respect to the output yields a curve in the parameter space. The result is a simplified geometric representation of the Morse-Smale complex in the high dimensional input domain. Finally, the geometric representation is embedded in 2D, using dimension reduction, to provide a visualization platform. The geometric properties of the regression curves enable the visualization of additional information about each crystal such as local and global shape, width, length, and sampling densities. The method is illustrated on several synthetic examples of two dimensional functions. Two use cases, using data sets from the UCI machine learning repository, demonstrate the utility of the proposed approach on real data. Finally, in collaboration with domain experts the proposed method is applied to two scientific challenges. The analysis of parameters of climate simulations and their relationship to predicted global energy flux and the concentrations of chemical species in a combustion simulation and their integration with temperature. PMID:20975167
One-dimensional opal photonic crystals
NASA Astrophysics Data System (ADS)
Kapitonov, A. M.
2008-12-01
One-dimensional opals are 1D self-assembled close packed colloidal crystals consisting of monodisperse colloidal globules. Polystyrene globules with sizes in the 1.9-10 μm range sit on a flat substrate and touch two neighbors in diametrally opposite contact points. These opals are quasi-1D photonic crystals. Optical modes, including whispering gallery modes of individual globules, coupled collective modes, and nanojet-induced modes, are visualized in 1D opals.
Three-dimensional display of document set
Lantrip, David B [Oxnard, CA; Pennock, Kelly A [Richland, WA; Pottier, Marc C [Richland, WA; Schur, Anne [Richland, WA; Thomas, James J [Richland, WA; Wise, James A [Richland, WA; York, Jeremy [Bothell, WA
2009-06-30
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Three-dimensional display of document set
Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.
2006-09-26
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may e transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Three-Dimensional Dispaly Of Document Set
Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.
2003-06-24
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Three-dimensional display of document set
Lantrip, David B [Oxnard, CA; Pennock, Kelly A [Richland, WA; Pottier, Marc C [Richland, WA; Schur, Anne [Richland, WA; Thomas, James J [Richland, WA; Wise, James A [Richland, WA
2001-10-02
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Method and apparatus for three dimensional braiding
NASA Technical Reports Server (NTRS)
Farley, Gary L. (Inventor)
1997-01-01
A machine for three-dimensional braiding of fibers is provided in which carrier members travel on a curved, segmented and movable braiding surface. The carrier members are capable of independent, self-propelled motion along the braiding surface. Carrier member position on the braiding surface is controlled and monitored by computer. Also disclosed is a yarn take-up device capable of maintaining tension in the braiding fiber.
Method and apparatus for three dimensional braiding
NASA Technical Reports Server (NTRS)
Farley, Gary L. (Inventor)
1995-01-01
A machine for three-dimensional braiding of fibers is provided in which carrier members travel on a curved, segmented and movable braiding surface. The carrier members are capable of independent, self-propelled motion along the braiding surface. Carrier member position on the braiding surface is controlled and monitored by computer. Also disclosed is a yarn take-up device capable of maintaining tension in the braiding fiber.
Three dimensional boundary layers in internal flows
NASA Technical Reports Server (NTRS)
Bodonyi, R. J.
1987-01-01
A numerical study of the effects of viscous-inviscid interactions in three-dimensional duct flows is presented. In particular interacting flows for which the oncoming flow is not fully-developed were considered. In this case there is a thin boundary layer still present upstream of the surface distortion, as opposed to the fully-developed pipe flow situation wherein the flow is viscous across the cross section.
On classification of m-dimensional algebras
NASA Astrophysics Data System (ADS)
Bekbaev, U.
2017-03-01
A constructive approach to the classification and invariance problems, with respect to basis changes, of the finite dimensional algebras is offered. A construction of an invariant open, dense (in the Zariski topology) subset of the space of structure constants of algebras is given. A classification of all algebras with structure constants from this dense set is given by providing canonical representatives of their orbits. A finite system of generators for the corresponding field of invariant rational functions of structure constants is shown.
Three Dimensional Inverse Synthetic Aperture Radar Imaging
1995-12-01
to upsample the projection data in order to get sufficient image quality. Working within these memory constraints, three-dimensional images were... metallic film on the windscreen in order to block reflections from the cockpit. Photographs and scale drawings of the model are shown in Figures 11 and...as well as spurious responses in the final image. Theoretically, sufficient resolution should have been available without upsampling the original data
Three-dimensional simulation of vortex breakdown
NASA Technical Reports Server (NTRS)
Kuruvila, G.; Salas, M. D.
1990-01-01
The integral form of the complete, unsteady, compressible, three-dimensional Navier-Stokes equations in the conservation form, cast in generalized coordinate system, are solved, numerically, to simulate the vortex breakdown phenomenon. The inviscid fluxes are discretized using Roe's upwind-biased flux-difference splitting scheme and the viscous fluxes are discretized using central differencing. Time integration is performed using a backward Euler ADI (alternating direction implicit) scheme. A full approximation multigrid is used to accelerate the convergence to steady state.
Three-Dimensional Shallow Water Acoustics
2014-09-30
sound can occur and produce significant three-dimensional (3-D) sound propagation effects. The long-term goals of this project are targeted on...efficient and accurate 3D acoustics models for studying underwater sound propagation in complex ocean environments. The ultimate scientific...objective is to study the underlying physics of the 3-D sound propagation effects caused jointly by physical oceanographic processes and geological features
Lossless compression for three-dimensional images
NASA Astrophysics Data System (ADS)
Tang, Xiaoli; Pearlman, William A.
2004-01-01
We investigate and compare the performance of several three-dimensional (3D) embedded wavelet algorithms on lossless 3D image compression. The algorithms are Asymmetric Tree Three-Dimensional Set Partitioning In Hierarchical Trees (AT-3DSPIHT), Three-Dimensional Set Partitioned Embedded bloCK (3D-SPECK), Three-Dimensional Context-Based Embedded Zerotrees of Wavelet coefficients (3D-CB-EZW), and JPEG2000 Part II for multi-component images. Two kinds of images are investigated in our study -- 8-bit CT and MR medical images and 16-bit AVIRIS hyperspectral images. First, the performances by using different size of coding units are compared. It shows that increasing the size of coding unit improves the performance somewhat. Second, the performances by using different integer wavelet transforms are compared for AT-3DSPIHT, 3D-SPECK and 3D-CB-EZW. None of the considered filters always performs the best for all data sets and algorithms. At last, we compare the different lossless compression algorithms by applying integer wavelet transform on the entire image volumes. For 8-bit medical image volumes, AT-3DSPIHT performs the best almost all the time, achieving average of 12% decreases in file size compared with JPEG2000 multi-component, the second performer. For 16-bit hyperspectral images, AT-3DSPIHT always performs the best, yielding average 5.8% and 8.9% decreases in file size compared with 3D-SPECK and JPEG2000 multi-component, respectively. Two 2D compression algorithms, JPEG2000 and UNIX zip, are also included for reference, and all 3D algorithms perform much better than 2D algorithms.
Mineralized Three-Dimensional Bone Constructs
NASA Technical Reports Server (NTRS)
Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)
2013-01-01
The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.
Three-Dimensional Ocean Noise Modeling
2015-03-01
particular attention paid to the case of Gaussian canyon . The solution to the three-dimensional wave equation in Cartesian co-ordinates can be written...in terms of a modal decomposition, carried out in the vertical and across- canyon horizontal directions. Work Completed 1. Nx2D and 3D Noise PE...azimuth in the Hudson Canyon [Figure 2). Additionally, the PE-reciprocity noise model was used to estimate the size, speed and distance from the
Three-dimensional ballistocardiography in weightlessness
NASA Technical Reports Server (NTRS)
Scano, A.
1981-01-01
An experiment is described the aim of which is to record a three dimensional ballistocardiogram under the condition of weightlessness and to compare it with tracings recorded on the same subject on the ground as a means of clarifying the meaning of ballistocardiogram waves in different physiological and perphaps pathological conditions. Another purpose is to investigate cardiovascular and possibly fluid adaptations to weightlessness from data collected almost simultaneously on the same subjects during the other cardiovascular during the other cardiovascular and metabolic experiments.
Three-dimensional adjustment of trilateration data
NASA Technical Reports Server (NTRS)
Sung, L.-Y.; Jackson, D. D.
1985-01-01
The three-dimensional locations of the monuments in the USGS Hollister trilateration network were adjusted to fit line length observations observed in 1977, using a Bayesian approach, and incorporating prior elevation estimates as data in the adjustment procedure. No significant discrepancies in the measured line lengths were found, but significant elevation adjustments (up to 1.85 m) were needed to fit the length data.
Analytical calculation of two-dimensional spectra.
Bell, Joshua D; Conrad, Rebecca; Siemens, Mark E
2015-04-01
We demonstrate an analytical calculation of two-dimensional (2D) coherent spectra of electronic or vibrational resonances. Starting with the solution to the optical Bloch equations for a two-level system in the 2D time domain, we show that a fully analytical 2D Fourier transform can be performed if the projection-slice and Fourier-shift theorems of Fourier transforms are applied. Results can be fit to experimental 2D coherent spectra of resonances with arbitrary inhomogeneity.
Three-Dimensional (3D) Distribution
2009-03-11
witnessed by ongoing efforts in both Afghanistan and Iraq , must turn distribution challenges into opportunities by mastering Three-Dimensional (3D...sustainment. 5 Joint Logistics Functions •Supply •Services •Maintenance •Transportation • Health Service Support •General Engineering Joint Personnel...Maintenance •Transportation • Health Service Support •Explosive Ordinance Disposal •Human Resource Support •Legal Support •Religious Support •Financial
Two-dimensional supramolecular electron spin arrays.
Wäckerlin, Christian; Nowakowski, Jan; Liu, Shi-Xia; Jaggi, Michael; Siewert, Dorota; Girovsky, Jan; Shchyrba, Aneliia; Hählen, Tatjana; Kleibert, Armin; Oppeneer, Peter M; Nolting, Frithjof; Decurtins, Silvio; Jung, Thomas A; Ballav, Nirmalya
2013-05-07
A bottom-up approach is introduced to fabricate two-dimensional self-assembled layers of molecular spin-systems containing Mn and Fe ions arranged in a chessboard lattice. We demonstrate that the Mn and Fe spin states can be reversibly operated by their selective response to coordination/decoordination of volatile ligands like ammonia (NH3). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Two-Dimensional Processing for Radar Systems
2001-11-01
residuals. This OP algorithm is distinct from the least-squares predictive- transform (LSPT) algorithm of Guerci and Feria (1996) in three important...algorithm (Guerci and Feria , 1996) ; however, in the OP and MC algorithms high levels of dimensionality reduction are attained with P + Q << N. The data-based...results in the minimum number of computations for a block processing method (Guerci and Feria , 1996). 35 5.0 MAXIMUM CORRELATION (MC) The MC algorithm
Progress in Multi-Dimensional Upwind Differencing
1992-09-01
advances in each of these components are discussed; putting them all together is the present focus of a worldwide research effort. Some numerical results ...as 1983 by Phil Roe [1]. A study of discrete multi-dimensional wave models by Roe followed in 1985 (ICASE Report 85-18, also [21), but it took until...consider the numerical results shown in Figure :3 and 4, taken from [:34] and [35], respectively. In Figure 3a the exact and discrete Mach-number
One Dimensional Analysis of Inertially Confined Plasmas.
1982-03-01
Sedov, L.I. Similarity and Dimensional Methods in Mechanics. New York: Academic Press, 1959. 26. Spitzer , Lyman , Jr . Physics of Fully Ionized Gases...Based on Maxwellian velocity distributions for both ions and electrons and defining t from the relation given by Spitzer (Ref 26:135), dt T...this coeffi- cient is given by Spitzer (Ttef 26:144), T (18) Heat flow caused by a temperature gradient results in a current, however, and this
Margin Based Dimensionality Reduction and Generalization
2010-01-01
S w , for the facial recognition tasks. On the other hand, S-LDA does not perform well at lower dimensional subspaces. But it 62 The Open...generalized optimal set of dis- criminant vectors,” Pattern Recognition , vol. 25, no. 7, pp. 731- 739, 1992. [27] P. Phillips, “The facial recognition ...USA Abstract: Linear discriminant analysis (LDA) for dimension reduction has been applied to a wide variety of problems such as face recognition
Three-Dimensional Printing in Orthopedic Surgery.
Eltorai, Adam E M; Nguyen, Eric; Daniels, Alan H
2015-11-01
Three-dimensional (3D) printing is emerging as a clinically promising technology for rapid prototyping of surgically implantable products. With this commercially available technology, computed tomography or magnetic resonance images can be used to create graspable objects from 3D reconstructed images. Models can enhance patients' understanding of their pathology and surgeon preoperative planning. Customized implants and casts can be made to match an individual's anatomy. This review outlines 3D printing, its current applications in orthopedics, and promising future directions.
Epistasis analysis using multifactor dimensionality reduction.
Moore, Jason H; Andrews, Peter C
2015-01-01
Here we introduce the multifactor dimensionality reduction (MDR) methodology and software package for detecting and characterizing epistasis in genetic association studies. We provide a general overview of the method and then highlight some of the key functions of the open-source MDR software package that is freely distributed. We end with a few examples of published studies of complex human diseases that have used MDR.
Real Imagery as a Three Dimensional Display
1991-12-01
under two categories--stereoscopic and autostereoscopic displays. The difference between these two displays is that autostereoscopic displays do not...require the use of special viewing glasses whereas stereoscopic displays do. In order to place a minimum incumbrance on the viewer, the autostereoscopic ...fooled into believing that the scene is three dimensional. This is accomplished even though the second view that normally comes with an autostereoscopic
Mineralized three-dimensional bone constructs
NASA Technical Reports Server (NTRS)
Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)
2011-01-01
The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.
Deeply subrecoil two-dimensional Raman cooling
Boyer, V.; Phillips, W.D.; Lising, L.J.; Rolston, S.L.
2004-10-01
We report the implementation of a two-dimensional Raman cooling scheme using sequential excitations along the orthogonal axes. Using square pulses, we have cooled a cloud of ultracold cesium atoms down to an rms velocity spread of 0.39(5) recoil velocities, corresponding to an effective transverse temperature of 30 nK (0.15T{sub rec}). This technique can be useful to improve cold-atom atomic clocks and is particularly relevant for clocks in microgravity.
A four dimensional variational analysis experiment
NASA Technical Reports Server (NTRS)
Hoffman, R.
1981-01-01
A demonstration that the four dimensional variational analysis method using the governing equations as exact constraints can be successfully employed for a perfect model and for a simple, but nonlinear, system is presented. The method is stable in an assimilation cycle. The method reconstructs the unobservable variables; in the case demonstrated, no velocity data was observed. The analysis errors are much smaller than the observing system errors.
One and Two Dimensional Discrete Wavelet Transforms
1992-09-01
dimensional case in Chapter IV. Chapter V proposes another method for decomposing the data at the expense of physical memory , the so-called multiple-phase...more efficient. Practically, this savings in memory is very insignificant, since the number of practical resolution levels is approximately [log2( I...filters, N, and the current resolution level, m: Ie.1 = Ic0I + (N-1)(2`-1) (43) So enough memory must be allocated if we desire lower and lower
Discovering Structure in High-Dimensional Data Through Correlation Explanation
2014-12-08
YOUR FORM TO THE ABOVE ADDRESS. University of Southern California Dept of Contracts and Grants University of Southern California Marina del Rey, CA 90292...California Marina del Rey, CA 90292 gregv@isi.edu Aram Galstyan Information Sciences Institute University of Southern California Marina del Rey, CA...am the life of the party”, on a five point scale: (1) disagree, (2) slightly disagree, (3) neutral, (4) slightly agree, and (5) agree.5 The data
Fault-tolerant computation with higher-dimensional systems
NASA Technical Reports Server (NTRS)
Gottesman, D.
1998-01-01
Instead of a quantum computer where the fundamental units are 2-dimensional qubits, the author considers a quantum computer made up of d-dimensional systems. There is a straightforward generalization of the class of stabilizer codes to d-dimensional systems, and he discusses the theory of fault-tolerant computation using such codes. He proves that universal fault-tolerant computation is possible with any higher-dimensional stabilizer code for prime d.