CMMSE: Study of a new symmetric anomaly in the elliptic, hyperbolic and parabolic Keplerian motion

In the present work, we define a new anomaly, $\Psi$, termed semifocal anomaly. It is determined by the mean between the true anomaly, $f$, and the antifocal anomaly, $f^{\prime}$; Fukushima defined $f^{\prime}$ as the angle between the periapsis and the secondary around the empty focus. In this first part of the paper, we take an approach to the study of the semifocal anomaly in the hyperbolic motion and in the limit case correspoding to the parabolic movement. From here we find a relation beetween the semifocal anomaly and the true anomaly that holds independently of the movement type. We focus on the study of the two-body problem when this new anomaly is used as the temporal variable.\\ In the second part, we show the use of this anomaly —combined with numerical integration methods— to improve integration errors in one revolution. Finally, we analyze the errors committed in the integration process —depending on several values of the eccentricity— for the elliptic, parabolic and hyperbolic cases in the apsidal region.

Effects of visual blur and contrast on spatial and temporal precision in manual interception

The visual system is said to be especially sensitive towards spatial but lesser so towards temporal information. To test this, in two experiments, we systematically reduced the acuity and contrast of a visual stimulus and examined the impact on spatial and temporal precision (and accuracy) in a manual interception task. In Experiment 1, we blurred a virtual, to-be-intercepted moving circle (ball). Participants were asked to indicate (i.e., finger tap) on a touchscreen where and when the virtual ball crossed a ground line. As a measure of spatial and temporal accuracy and precision, we analyzed the constant and variable errors, respectively. With increasing blur, the spatial and temporal variable error, as well as the spatial constant error increased, while the temporal constant error decreased. Because in the first experiment, blur was potentially confounded with contrast, in Experiment 2, we re-ran the experiment with one difference: instead of blur, we included five levels of contrast matched to the blur levels. We found no systematic effects of contrast. Our findings confirm that blurring vision decreases spatial precision and accuracy and that the effects were not mediated by concomitant changes in contrast. However, blurring vision also affected temporal precision and accuracy, thereby questioning the generalizability of the theoretical predictions to the applied interception task.

Meteorological property and temporal variable effect on spatial semivariance of infrared thermography of soil surfaces for detection of foreign objects

The environmental phenomenological properties responsible for the thermal variability evident in the use of thermal infrared (IR) sensor systems is not well understood. The research objective of this work is to understand the environmental and climatological properties contributing to the temporal and spatial thermal variance of soils. We recorded thermal images of surface temperature of soil as well as several meteorological properties such as weather condition and solar irradiance of loamy soil located at the Cold Regions Research and Engineering Lab (CRREL) facility. We assessed sensor performance by analyzing how recorded meteorological properties affected the spatial structure by observing statistical differences in spatial autocorrelation and dependence parameter estimates.

A Spectral Collocation Technique for Riesz Fractional Chen-Lee-Liu Equation

This paper discusses the study of optical solitons that are modeled by Riesz fractional Chen-Lee-Liu model, one of the versions of the famous nonlinear Schrödinger equation. This model is solved by the assistance of consecutive spectral collocation technique with two independent approaches. The first is the approach of the spatial variable, while the other is the approach of the temporal variable. It is concluded that the method of the current paper is far more efficient and credible for the proposed problem. Numerical results illustrate the performance efficiency of the algorithm. The results also point out that the scheme can lead to spectral accuracy of the studied model.

Análisis jurídico de la aplicación de las técnicas de reproducción humana asistida en Cuba

El artículo reúne reflexiones jurídicas respecto a la aplicación y desarrollo de las técnicas de reproducción humana asistida y su repercusión para las ciencias del Derecho. Las técnicas de reproducción humana asistida consisten en la manipulación de los gametos y embriones a través de diversos procedimientos, las más usuales son la inseminación artificial, la fecundación in vitro y la microinyecciónintracitoplasmática. Su aplicación despliega repercusiones éticas, morales, psicológicas y jurídicas, estableciéndose divergencias en cuanto a su tratamiento. El Derecho como ciencia y creación social no es inmutable ni amovible, sino temporal, variable y dinámico puesto que debe adecuarse a todos los cambios sociales, culturales, políticos, económicos y científicos. Sin embargo, a través del transcurso del tiempo se percibe que el Derecho no corre al mismo paso de la ciencia. Debido a los resultados implementados, ajustar el ordenamiento jurídico al desarrollo alcanzado por la aplicación de las técnicas de reproducción humana asistida, a través del estudio de los disímiles problemas jurídicos que origina, tales como la determinación de la filiación materna y/o paterna, constituye una necesidad apremiante en el sistema cubano de Derecho actual. En Cuba, al igual que varios países de América del Sur, no existe legislación al respecto por lo que la formulación de una ley especial destinada a regular la aplicación y desarrollo de las técnicas constituye una tarea pendiente en el perfeccionamiento legislativo del Derecho cubano. El objetivo es fundamentar la necesidad de regulación de las técnicas de reproducción humana asistida en el ordenamiento jurídico cubano.

The Fornberg-Whitham Equation Solved by the Differential Transform Method

The Differential Transform Method is a powerful analytical method that can solve nonlinear partial differential equations. Yet, the method cannot be used to solve time-dependent partial differential equations that involve more than one partial derivative with respect to the temporal variable t when they are of the same order, as in the case of the Fornberg-Whitham type equations. In this paper, a new theorem is devised to overcome the aforementioned problem ofthe method, and it has been successfully applied to solve the Fornberg-Whitham equation. The other equations belonging to this group of equations, such as the Camassa-Holm equation and the Degasperi-Procesi equation, may also be solved by this approach.

Modelo de pluma segmento com velocidades estocásticas para dispersão atmosférica em condições de vento fraco

This work presents an analytical solution for the transient three-dimensional advection-diffusion equation. This solution, obtained from a combination of the variable separation method and GILTT (Generalized Integral Laplace Transform Technique) is used to simulate the pollutant dispersion in the atmosphere. The new solution has the advantage of not requiring a numerical inversion performed in the temporal variable in works using only GILTT technique. The model was tested in low wind condition, with diffusion in transverse and longitudinal directions and stochastic speeds. Simulations were performed for the INEL experiment. The analytical character of the model makes it simple, which represents advantages in its development and implementation, as well as in the computational cost for execution.

Comprendiendo la Economía Venezolana: Petróleo y dependencia externa

El presente artículo examina la economía venezolana a través del análisis del producto agregado, por el lado de la demanda y por el lado de la oferta. En función de la disponibilidad de datos, se emplean distintas fuentes en un horizonte temporal variable, que oscila entre 1950 y 2017. Se evidencia que la crisis económica tiene causas estructurales, donde subyace un sector externo que impone límites al crecimiento económico. Durante la Revolución Bolivariana, la economía venezolana se ha caracteriza por crecer con base al consumo y las exportaciones. Por otro lado, su inversión mostró una fuerte dependencia de las importaciones que, a su vez, dependen de la mono-exportación de petróleo. Por tanto, el modelo basado en el consumo interno se agota, ante la ausencia de cambios en la estructura productiva que permitan sustituir la renta petrolera

Lump solutions to nonlinear PDEs involving Hirota derivative Dt2DxDy

This paper aims to study lump solutions to a class of (2[Formula: see text]+[Formula: see text]1)-dimensional nonlinear PDE systems, which involve the fourth-order Hirota derivative term: [Formula: see text]. This Hirota derivative term generates higher-order derivatives of the temporal variable. Lump solutions to the resulting new class of nonlinear PDE systems are studied in detail via the Hirota bilinear method.