Application of the Verlet method for the simulation of a gravitational system of n bodies

En este trabajo se plantea una solución numérica (simulación por software) del “problema de n cuerpos” que interactúan gravitacionalmente basada en la formulación de Verlet. Adicionalmente se diseña un programa que gráficamente muestra los resultados de esta solución numérica, que detalla las diferentes trayectorias, para diferentes condiciones de masa, velocidad y distancia entre los n objetos que interactúan. La interacción del usuario con la interfaz gráfica, se realiza partícula a partículaIn this paper we propose a numerical solution (software simulation) of the "problem of n bodies" that interact gravitationally based on the formulation of Verlet. Additionally a program is designed that graphically shows the results of this numerical solution, which details the different trajectories, for different conditions of mass, speed and distance between the n objects that interact. The interaction of the user with the graphical interface, is performed particle by particle.Peer Reviewe

Synthesis of Spherical 4R Mechanism for Path Generation using Differential Evolution

The problem of path generation for the spherical 4R mechanism is solved using the Differential Evolution algorithm (DE). Formulas for the spherical geodesics are employed in order to obtain the parametric equation for the generated trajectory. Direct optimization of the objective function gives the solution to the path generation task without prescribed timing. Therefore, there is no need to separate this task into two stages to make the optimization. Moreover, the order defect problem can be solved without difficulty by means of manipulations of the individuals in the DE algorithm. Two examples of optimum synthesis showing the simplicity and effectiveness of this approach are included.Comment: Submitted to Mechanism and Machine Theor

Application of the Verlet method for the simulation of a gravitational system of n bodies

In this paper we propose a numerical solution (software simulation) of the "problem of n bodies" that interact gravitationally based on the formulation of Verlet. Additionally a program is designed that graphically shows the results of this numerical solution, which details the different trajectories, for different conditions of mass, speed and distance between the n objects that interact. The interaction of the user with the graphical interface, is performed particle by particle.&nbsp

Esbozo de la semiótica con perspectiva sistémica

La Comunicación humana esté compuesta por fenómenos sociales que no estén totalmente caracterizados, por lo tanto no hay un acuerdo que identifique su problema u objeto de estudio. Este trabajo presenta una revisión del concepto de Comunicación desde la Metodología de Sistemas Suaves, obteniendo una visión holística de los fenómenos comunicativos. Concluimos con la propuesta de una semiótica cuantitativa para caracterizar los eventos comunicativos plurales y sus cualidades. The human communication is integrated by social phenomena, not yet characterized at all, therefore there isn’t an agreement identifying its problem or aim of study. This work presents a review of the concept of communication from the Soft Systems Methodology obtaining an holistic vision of the communicative phenomena. We conclude suggesting a quantitative Semiotics proposal to characterize the plural communicative events and its qualitie

Use of Telemedicine for Post-discharge Assessment of the Surgical Wound: International Cohort Study, and Systematic Review with Meta-analysis

Objective: This study aimed to determine whether remote wound reviews using telemedicine can be safely upscaled, and if standardised assessment tools are needed. Summary background data: Surgical site infection is the most common complication of surgery worldwide, and frequently occurs after hospital discharge. Evidence to support implementation of telemedicine during postoperative recovery will be an essential component of pandemic recovery. Methods: The primary outcome of this study was surgical site infection reported up to 30-days after surgery (SSI), comparing rates reported using telemedicine (telephone and/or video assessment) to those with in-person review. The first part of this study analysed primary data from an international cohort study of adult patients undergoing abdominal surgery who were discharged from hospital before 30-days after surgery. The second part combined this data with the results of a systematic review to perform a meta-analysis of all available data conducted in accordance with PRIMSA guidelines (PROSPERO:192596). Results: The cohort study included 15,358 patients from 66 countries (8069 high, 4448 middle, 1744 low income). Of these, 6907 (45.0%) were followed up using telemedicine. The SSI rate reported using telemedicine was slightly lower than with in-person follow-up (13.4% vs. 11.1%, P<0.001), which persisted after risk adjustment in a mixed-effects model (adjusted odds ratio: 0.73, 95% confidence interval 0.63-0.84, P<0.001). This association was consistent across sensitivity and subgroup analyses, including a propensity-score matched model. In nine eligible non-randomised studies identified, a pooled mean of 64% of patients underwent telemedicine follow-up. Upon meta-analysis, the SSI rate reported was lower with telemedicine (odds ratio: 0.67, 0.47-0.94) than in-person (reference) follow-up (I2=0.45, P=0.12), although there a high risk of bias in included studies. Conclusions: Use of telemedicine to assess the surgical wound post-discharge is feasible, but risks underreporting of SSI. Standardised tools for remote assessment of SSI must be evaluated and adopted as telemedicine is upscaled globally