Search results for "Crash"

Evaluation of Roundabout Safety Performance through Surrogate Safety Measures from Microsimulation

2018

The paper presents a microsimulation-based approach for roundabout safety performance evaluation. Based on a sample of Slovenian roundabouts, the vehicle trajectories exported from AIMSUN and VISSIM were used to estimate traffic conflicts using the Surrogate Safety Assessment Model (SSAM). AIMSUN and VISSIM were calibrated for single-lane, double-lane and turbo roundabouts using the corresponding empirical capacity function which included critical and follow-up headways estimated through meta-analysis. Based on calibration of the microsimulation models, a crash prediction model from simulated peak hour conflicts for a sample of Slovenian roundabouts was developed. A generalized linear model…

Crash Response of a Repaired Vehicle - Influence of Welding UHSS Members

2020

Not all bull and bear markets are alike: insights from a five-state hidden semi-Markov model

2022

This paper employs the hidden semi-Markov model and a novel model selection procedure to detect different states in the US stock market. The empirical results suggest that the market is switching between five states that can be classified into three bull states and two bear states. The three bull states are categorized as a low volatility bull market, a high volatility bull market, and a stock market bubble. One of the bear states represents a regular bear market, while the other one corresponds to either a stock market crash or a market correction. The paper demonstrates that the five-state model is consistent with a number of stylized facts and provides many valuable insights into the dyn…

Behavioral Health at School: Do Three Competences in Road Safety Education Impact the Protective Road Behaviors of Spanish Children?

2019

Background: Education in road safety (also known as Road Safety Education&mdash

Advanced breast cancer at presentation (ABC-p) in octogenarian women (OW): Specific elderly-devoted risk tests(SEDRT) (CARG+CRASH) as new tools to pr…

2021

e12510 Background: Due to current lengthening of average lifespan and progressive increase of malignant tumors in mankind, more new strategies must be constantly sought especially for thirdage neoplasms. Nevertheless because severe toxicity developed in the majority of frail patients, administration of therapy may cause high risk of life-threatening AIM: We have considered in this paper ABC in frail patients like OW. Purpose of the study is preliminary detection of the overall toxicity (OTox) through the possible use of specifics tests adopted specially in frail patients such as OW, to ensure greater control in drugs administration with good effectiveness. AIM: We have considered in this p…

Multiresolution wavelet-based approach to identification of modal parameters of a vehicle full-scale crash test

2012

In this work estimation of vehicle modal parameters was achieved by application of a wavelet-based method. The time-frequency analysis, which comprises those techniques that study a signal in both the time and frequency domains simultaneously, using Morlet wavelet properties are applied to the measured acceleration pulse of the colliding vehicle. Determination of the ridge of the wavelet coefficients matrix makes it possible to identify the frequency components of the recorded crash pulse. Subsequently, by using the estimated natural frequency of the system, the values of damping factor for a given mode shape are assessed. In this work there are concerned both: the major frequencies of the …

Energy analysis of a non-linear dynamic impact using FEM

2014

In the car industry, the Finite Element Method (FEM) is being more and more used to analyze the crashworthiness performance of vehicles. In order to validate the results, these impact simulations are normally compared with real crash footage and acceleration data. This paper studies the deformation- and energy output of a simple dummy model during a non-linear dynamic impact. The dummy model is crashed into an obstacle at three different velocities to observe the energy dissipated through different damping mechanisms. Furthermore, in impact simulations, material damping plays an important role in energy dissipation. However, it can be difficult to determine realistic damping parameter value…

2014

In this paper mathematical modeling of a vehicle crash test based on a single-mass is studied. The model under consideration consists of a single-mass coupled with a spring and/or a damper. The parameters for the spring and damper are obtained by analyzing the measured acceleration in the center of gravity of the vehicle during a crash. A model with a nonlinear spring and damper is also proposed and the parameters will be optimized with different damper and spring characteristics and optimization algorithms. The optimization algorithms used are interior-point and firefly algorithm. The objective of this paper is to compare different methods used to establish a simple model of a car crash an…

Optimization of Vehicle-to-Vehicle Frontal Crash Model Based on Measured Data Using Genetic Algorithm

2017

In this paper, a mathematical model for vehicle-to-vehicle frontal crash is developed. The experimental data are taken from the National Highway Traffic Safety Administration. To model the crash scenario, the two vehicles are represented by two masses moving in opposite directions. The front structures of the vehicles are modeled by Kelvin elements, consisting of springs and dampers in parallel, and estimated as piecewise linear functions of displacements and velocities, respectively. To estimate and optimize the model parameters, a genetic algorithm approach is proposed. Finally, it is observed that the developed model can accurately reproduce the real kinematic results from the crash test…

Determinants of interest margins in Spanish credit institutions before and after the 2008 financial crash

2017

As interest margins of credit institutions affect economic performance of countries, finding out which are the main determinants of their evolution is a research task of great interest at current times. This is the purpose of the present paper as regards to the Spanish case over the period 2004-2012. Based on the econometric contributions by Ho and Saunders (1981) and some of its extensions, the authors develop a model that includes as explanatory variables the factors usually examined in the literature and other singular variables that might be relevant. Particularly, the rate of leverage, the quality of their assets measured according to their risk, and the profit obtained from the sellin…