An electrodynamics model for Data Interpretation and Numerical Analysis of ionospheric Missions and Observations (DINAMO)

We introduce a new numerical model developed to assist with Data Interpretation and Numerical Analysis of ionospheric Missions and Observations (DINAMO). DINAMO derives the ionospheric electrostatic potential at low- and mid-latitudes from a two-dimensional dynamo equation and user-specified inputs for the state of the ionosphere and thermosphere (I–T) system. The potential is used to specify the electric fields and associated F-region E × B plasma drifts. Most of the model was written in Python to facilitate the setup of numerical experiments and to engage students in numerical modeling applied to space sciences. Here, we illustrate applications and results of DINAMO in two different analyses. First, DINAMO is used to assess the ability of widely used I–T climatological models (IRI-2016, NRLMSISE-00, and HWM14), when used as drivers, to produce a realistic representation of the low-latitude electrodynamics. In order to evaluate the results, model E × B drifts are compared with observed climatology of the drifts derived from long-term observations made by the Jicamarca incoherent scatter radar. We found that the climatological I–T models are able to drive many of the features of the plasma drifts including the diurnal, seasonal, altitudinal and solar cycle variability. We also identified discrepancies between modeled and observed drifts under certain conditions. This is, in particular, the case of vertical equatorial plasma drifts during low solar flux conditions, which were attributed to a poor specification of the E-region neutral wind dynamo. DINAMO is then used to quantify the impact of meridional currents on the morphology of F-region zonal plasma drifts. Analytic representations of the equatorial drifts are commonly used to interpret observations. These representations, however, commonly ignore contributions from meridional currents. Using DINAMO we show that that these currents can modify zonal plasma drifts by up to ~ 16 m/s in the bottom-side post-sunset F-region, and up to ~ 10 m/s between 0700 and 1000 LT for altitudes above 500 km. Finally, DINAMO results show the relationship between the pre-reversal enhancement (PRE) of the vertical drifts and the vertical shear in the zonal plasma drifts with implications for equatorial spread F.

Structural optimization of concrete plane frames considering the static and dynamic wind effect

abstract: This study has as its main purpose the structural optimization of plane frames in concrete, having as the objective function the minimum total weight of the structure. For this purpose, external actions, considered within the optimization process, are intended to represent accurately all effects observed in a real situation. In such manner, loads are dependent on the cross-section obtained in each optimization step, as well as the static and dynamic effects of the wind are considered for a more realistic representation. The optimization method adopted is the Teaching-Learning Based Optimization (TLBO). Thus, all proper design constraints were considered in accordance with Brazilian standards for concrete structures. From the results obtained in both situations (static and dynamic effects), it is possible to notice the difference regarding external actions, in which higher loads were obtained in higher floors, using the simplified dynamic model proposed in standards. Regarding the analysis of the structure optimization, the weight was higher when the applied forces were the result of the dynamic wind model, in which the larger cross-sections were found at the bottom of the structure. Even though this may be a well-known issue, the present work shows a quantitative study in which both effects are discussed in detail, as well as it features a methodology, based on a novel optimization method and with a straightforward implementation, that could be adapted for the analysis of more complex structures.

HUMAN BODY MODELING TECHNOLOGIES FOR E-COMMERCE SYSTEMS

Relevance of the research work is the analysis of the main features of 3D modeling for further implementation in e-commerce. Namely, the features ofcreating a human body 3D model with the ability to edit personal settings of individual parts of the body, as well as a basic set of clothes to provide amore realistic representation of the model. The features of the 3D model in general were considered in this article. The mathematical analysis of the 3Dgraphics rendering on the 2D monitor and the possibilities of control and editing of such models have been presented. The developed software productallows the user to create an anatomical three-dimensional model of the human body and then adjust it to his needs. The user can apply on createdmodel variety of settings, namely more than 15 different views, with a full package of changes. It is possible to change the size, color of hair,eyebrows, eyes, face, body, legs. Also, the user is able to select the levels of skeletal frame views and additionally can select different backgrounds toprovide a more realistic representation of the model in space. Additional functionality was implemented for more flexible configuration of the model’sface. The user can pre-determine points to select directions or sizes of different parts of the face using settings, displayed on the mouse or touchpadcontrol. After adjustments, the user is able to manage the clothes that he had saved in the shopping cart from the online store, from which he laterproceeded to the online fitting. After the fitting the user can test the creation of animations in 360 degrees of free movement. Finally, the user can go tothe store to pay for the items he left in the shopping cart. Developed software allows improving main metrics of the on-line stores, which has a positiveimpact on increasing the growth of earnings.

Modeling a unit cell: crystallographic refinement procedure using the biomolecular MD simulation platform Amber

A procedure has been developed for the refinement of crystallographic protein structures based on the biomolecular simulation program Amber. The procedure constructs a model representing a crystal unit cell, which generally contains multiple protein molecules and is fully hydrated with TIP3P water. Periodic boundary conditions are applied to the cell in order to emulate the crystal lattice. The refinement is conducted in the form of a specially designed short molecular-dynamics run controlled by the Amber ff14SB force field and the maximum-likelihood potential that encodes the structure-factor-based restraints. The new Amber-based refinement procedure has been tested on a set of 84 protein structures. In most cases, the new procedure led to appreciably lower R free values compared with those reported in the original PDB depositions or obtained by means of the industry-standard phenix.refine program. In particular, the new method has the edge in refining low-accuracy scrambled models. It has also been successful in refining a number of molecular-replacement models, including one with an r.m.s.d. of 2.15 Å. In addition, Amber-refined structures consistently show superior MolProbity scores. The new approach offers a highly realistic representation of protein–protein interactions in the crystal, as well as of protein–water interactions. It also offers a realistic representation of protein crystal dynamics (akin to ensemble-refinement schemes). Importantly, the method fully utilizes the information from the available diffraction data, while relying on state-of-the-art molecular-dynamics modeling to assist with those elements of the structure that do not diffract well (for example mobile loops or side chains). Finally, it should be noted that the protocol employs no tunable parameters, and the calculations can be conducted in a matter of several hours on desktop computers equipped with graphical processing units or using a designated web service.

Modelling the volcanic ash plume from Eyjafjallajökull eruption (May 2010) over Europe: evaluation of the benefit of source term improvements and of the assimilation of aerosol measurements

Numerical dispersion models are used operationally worldwide to mitigate the effect of volcanic ash on aviation. In order to improve the representation of the horizontal dispersion of ash plumes and of the 3D concentration of ash, a study was conducted using the MOCAGE model during the European Natural Airborne Disaster Information and Coordination System for Aviation (EUNADICS-AV) project. Source term modelling and assimilation of different data were investigated. A sensitivity study of source term formulation showed that a resolved source term, using the FPLUME plume rise model in MOCAGE, instead of a parameterised source term, induces a more realistic representation of the horizontal dispersion of the ash plume. The FPLUME simulation provides more concentrated and focused ash concentrations in the horizontal and the vertical dimensions than the other source term. The assimilation of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth has an impact on the horizontal dispersion of the plume, but this effect is rather low and local compared to source term improvement. More promising results are obtained with the continuous assimilation of ground-based lidar profiles, which improves the vertical distribution of ash and helps in reaching realistic values of ash concentrations. Using this configuration, the effect of assimilation may last for several hours and it may propagate several hundred kilometres downstream of the lidar profiles.

Simulation of RSO Images for Space Situation Awareness (SSA) Using Parallel Processing

With the rapid increase in resident space objects (RSO), there is a growing demand for their identification and characterization to advance space simulation awareness (SSA) programs. Various AI-based technologies are proposed and demonstrated around the world to effectively and efficiently identify RSOs from ground and space-based observations; however, there remains a challenge in AI training due to the lack of labeled datasets for accurate RSO detection. In this paper, we present an overview of the starfield simulator to generate a realistic representation of images from space-borne imagers. In particular, we focus on low-resolution images such as those taken with a commercial-grade star tracker that contains various RSO in starfield images. The accuracy and computational efficiency of the simulator are compared to the commercial simulator, namely STK-EOIR to demonstrate the performance of the simulator. In comparing over 1000 images from the Fast Auroral Imager (FAI) onboard CASSIOPE satellite, the current simulator generates both stars and RSOs with approximately the same accuracy (compared to the real images) as STK-EOIR and, an order of magnitude faster in computational speed by leveraging parallel processing methodologies.

How Much Should We Spend to Fight against Climate Change? The Value of Backstop Technologies in a Simplified Model

The estimation of the social cost of climate change is typically carried out with complex, difficult to interpret, integrated assessment models (IAMs). Instead, this paper presents a simple, tractable model with which to estimate the willingness to pay of societies against climate change. The model is based on an already comprehensive and intuitive one developed by Besley and Dixit, which has been modified by including a backstop technology (e.g., a renewable energy technology). This improved formulation allows for a more realistic representation of the climate change problem in that it is able to include the decoupling of economic growth and GHG emissions. The model allows us to understand the implications of different assumptions, such as the rate of growth of the economy, or the damages expected from climate change, on the willingness to pay against it. Our results show that, for a baseline scenario, the willingness to pay (WTP) is 0.52% of annual GDP, lower than that obtained by Besley and Dixit, which shows the significant benefits of developing competitive mitigation technologies. Our results also show the benefits of international collaboration, or of devoting more resources to R&D, as efficient ways to fight against climate change.

The Filmic Literary Works of Gabriel García Márquez

Cinema is a very important area of GGM literary activity, which the author conceived as another way to tell stories, in parallel and connected to the ways novels/stories and journalism tell stories of their own. This article addresses the work of García Márquez as a filmic writer. After briefly explaining the influence of cinema on his literary education, the article focuses on some problems in the writing of subjects and screenplays in relation to film production, which also concerned García Márquez. His film work is discussed in chronological order, while also highlighting the more relevant thematic and aesthetic elements. The theme of destiny opens and closes the discourse, given that it is present both in the first and last important screenplays by the author, Tiempo de morir and Edipo Alcalde, linked to the influence of Sophocles’s Oedipus Rex. Another relevant theme is that of the tension between realistic representation and the different forms of transfiguration of reality, via fantastic elements, absurd situations, and hyperbolic intensifications. Such aspects may be found in the screenplays of many films written by GGM between the 1970s and 1980s: Presagio, El año de la peste, María de mi corazón, Eréndira, Un señor muy viejo con unas alas enormes, and the series Amores difíciles. Finally, the article focuses on some unexecuted projects: unpublished screenplays or film stories, such as “Dios y yo”, “Para Elisa”, and “Blacamán”, which show the richness of the filmic imagination of García Márquez.

STACKED DELTA DESIGN OF THREE-PHASE PERMANENT-MAGNET FAULT CURRENT LIMITERS

This paper proposes an improvement for the dynamic performance of presaturated stacked permanent magnet biased three-phase fault current limiter (PMFCL) through COMSOL finite element simulation. The nonlinear demagnetization behavior of the permanent magnet, especially in the upper part of the B-H curve with negative magnetic field intensity, has been modelled through the Jiles-Atherton method. This enables a realistic representation of the PMFCL dynamic behavior throughout its entire operations of pre-fault, fault and fault removal, respectively. The experimental measurements have been considered to validate the trends of the simulation outcomes during the entire operation of PMFCL. Extensive finite element simulation shows that the stacked design of PMFCL can increase the capability of fault current limiting with proper selection of the number and arrangement of the AC coils around the iron core (soft magnet). Results reveal that the division of AC coils into series differential connected subcoils, with an even number, can increase the limiting capability with increasing the AC coil number of turns, without exceeding the permissible tolerances of voltage drop and power losses. Moreover, this stacked design is subjected to parametric investigation for different fault types, either symmetrical or unsymmetrical, or even when changing the fault current peak value.

Development of a new militarily-relevant whole-body low-intensity blast model for mild and subconcussive traumatic brain injury: Examination of acute neurological and multi-organ pathological outcomes

This work describes a newly developed experimental mouse model reproducing features of blast-induced neurotrauma (BINT), induced in operationally relevant manner using a compressed air-driven shock tube. Mild BINT (smBINT) was induced by one exposure to a low-intensity blast (LIB), whereas subconcussive BINT (rscBINT) was caused by repeated exposures to LIB. To mimic an operational scenario when a soldier is standing when exposed to blast using a quadruped experimental animal (mouse), a whole-body holder was developed to position mice in a bipedal stance, face-on toward the pressure wave generated in a shock tube. This restraint avoids bobble head movement, thus prevents tertiary blast effects, and allows administration of fast-acting inhaled anesthetics via nose cone. Using this model, we established and validated paradigms for primary blast-induced mild and repetitive traumatic brain injuries Our results showed that a single exposure to 69 kPa (10 psi) was capable of inducing smBINT, whereas three-rounds of exposure to 41 kPa (6 psi) caused rscBINT. Mice recovered rapidly from both types of BINT without prolonged neurological dysfunction. Mild superficial pathology was found predominantly in the lungs 24h after injury, with equivalent pathology after smBINT or repetitive rscBINT. The Purkinje layer of the cerebellum exhibited neuronal damage persisting up to 7d. Similar to some other models as well as clinical findings, this model reproduces blast-induced cerebellar pathology. In conclusion, this model positioning mice in a bipedal stance and facing front-on toward the shockwave provides realistic representation of operational scenarios and reproduces militarily-relevant smBINT and rscBINT in the laboratory.