The effects of obesity on occupant injury risk in frontal impact: a computer modeling approach

Obesity is a condition that affects about 40% of US adults, and people with disabilities have a higher incidence of obesity than able-bodied individuals. Motor vehicle collisions (MVCs) are the number one cause of death in individuals under the age of 34 in the US, and people who ride in vehicles while seated in their wheelchairs are at increased risk of injury compared to people who ride in the automotive seat. Obese occupants appear to have a different risk of injury in MVCs than non-obese individuals. To reduce the risk of injury to obese occupants it is necessary to further understand the injury mechanisms to obese individuals in frontal MVCs. The purpose of this research was to investigate the mechanisms of injury and injury risk to obese occupants and obese wheelchair-seated occupants in frontal impact. Three full body occupant models were created to investigate the effects of increased mass, changes in obese torso mechanical response and geometry, and a combination of mass and torso changes on occupant injury risk. To investigate the effects of obesity on wheelchair-seated occupants a wheelchair/occupant model was created and validated. Parametric studies were used on all the models to investigate injury risk in frontal impact. The results show that increased mass is the most significant factor leading to injury for obese occupants. The differences in torso mechanical response and geometry as a result of increased adipose tissue in obese occupants, do not significantly affect the injury risk of obese occupants. Changes in the obese torso coupled with increased mass cause increased pelvis and chest excursion which results in increased risk of lower extremity injury. As BMI increases in wheelchair-seated occupants the risk of lower extremity injury increases, and obese wheelchair-seated occupants have a higher risk of injury to the lower extremities than obese non wheelchair-seated occupants. This research suggests that the reduction in injuries to certain body regions reported in the literature are not due to a "cushion effect," but are more likely due to altered occupant kinematics that transfer load from the upper body to the lower extremities

Factores que influyen en los métodos de inversión de China en Latinoamérica (2005- 2022)

La inversión china en Latinoamérica se ha incrementado de modo significativo en las últimas dos décadas, lo que ha dado origen a numerosos estudios e hipótesis sobre las motivaciones del gigante asiático y sus consecuencias en la región. Este estudio expande sobre dicha literatura y analiza con más detalle los métodos de la inversión de China en Latinoamérica durante el período de 2005 a 2022. Para el desarrollo metodológico, se utilizaron como variables el tamaño del mercado, la explotación de recursos naturales, la calidad institucional y la posición de cada país de la región con respecto a Taiwán. A su vez, se realizaron dos modelos de regresión POLS para analizar las distintas hipótesis. El primer modelo analizó la inversión total china en su conjunto como porcentaje del PBI anual del país receptor. En el segundo modelo se abordó la proporción de IED y préstamos de China al país receptor. Entre los resultados más relevantes, se encontró que entre los determinantes de las inversiones de China en Latinoamérica se cuentan las características de cada país y pesan cuestiones de naturaleza política y económica. También se encontró que China tiende a emplear el método de inversión de IED (Inversión Extranjera Directa) en aquellos países con instituciones robustas y mercados grandes. En el caso de países con instituciones débiles, las inversiones tienden a realizarse con financiamiento directo. Como conclusión, los factores que afectan el instrumento de inversión pueden ser de índole económica, política doméstica o política exterior

Advanced information processing system: Hosting of advanced guidance, navigation and control algorithms on AIPS using ASTER

This program demonstrated the integration of a number of technologies that can increase the availability and reliability of launch vehicles while lowering costs. Availability is increased with an advanced guidance algorithm that adapts trajectories in real-time. Reliability is increased with fault-tolerant computers and communication protocols. Costs are reduced by automatically generating code and documentation. This program was realized through the cooperative efforts of academia, industry, and government. The NASA-LaRC coordinated the effort, while Draper performed the integration. Georgia Institute of Technology supplied a weak Hamiltonian finite element method for optimal control problems. Martin Marietta used MATLAB to apply this method to a launch vehicle (FENOC). Draper supplied the fault-tolerant computing and software automation technology. The fault-tolerant technology includes sequential and parallel fault-tolerant processors (FTP & FTPP) and authentication protocols (AP) for communication. Fault-tolerant technology was incrementally incorporated. Development culminated with a heterogeneous network of workstations and fault-tolerant computers using AP. Draper's software automation system, ASTER, was used to specify a static guidance system based on FENOC, navigation, flight control (GN&C), models, and the interface to a user interface for mission control. ASTER generated Ada code for GN&C and C code for models. An algebraic transform engine (ATE) was developed to automatically translate MATLAB scripts into ASTER