Basin stability of single machine infinite bus power systems with Levy type load fluctuations

10th International Conference on Electrical and Electronics Engineering, ELECO 2017; Bursa; Turkey; 29 November 2017 through 2 December 2017In this paper, the basin stability of single machine infinite bus power systems with alpha-stable Levy type load fluctuations are investigated over the parameter space of mechanical power and damping parameter. The probabilities of returning to the stable equilibrium point are calculated for different characteristic exponent and skewness parameters of alpha-stable Levy noise to see the effect of impulsive and asymmetric load fluctuations

Bayesian stable mixture model of state densities of generalized Chua's circuit

In this paper, the probability density functions (PDFs) of the states of Generalized Chua's Circuit (GCC) have been modeled by Finite Mixture α-Stable (FMαS) distributions which is a Bayesian mixture model of α-stable distributions and it provides semiparametric characterization for the distributions of multiscroll chaotic attractors. Fully Bayesian approach has been applied to estimate the mixture parameters of multimodal distributions corresponding to the multiscroll chaotic attractors

The effect of including a fetus in the uterus model on the risk of fetus mortality through drop test and frontal crash simulations

© 2016 Informa UK Limited, trading as Taylor & Francis Group Computational modelling is an effective way of estimating the risk of injuries and fatalities in road traffic accidents. Computational pregnant occupant modelling has an additional important role in the investigation of the risk of fetus mortality in crash test simulations. In this paper, the effect of including the fetus in the uterus of the pregnant occupant model is investigated. First, isolated drop test simulations with the uterus of the computational pregnant occupant model, ‘Expecting’, with and without a fetus are used to show the effect of the presence of fetus in the uterus model. Then ‘Expecting’ with and without the fetus is used with varying levels of restraint system use, such as fully restrained, ‘seatbelt only’, ‘airbag only’ and ‘no restraint’, in frontal crash simulations, representing five levels of impacts. Maximum strains developed in the uteroplacental interface with and without a fetus are compared in every case. Both simulations predict higher risks of placental abruption when the fetus is included in the model. Simulations with and without a fetus model show that inclusion of a 38-week fetus model causes higher strains in the placental region of uterus

Pregnant driver injury investigations through modelling and simulation of full-frontal crashes with and without airbags

Road traffic accidents have become increasingly important element in maternal deaths. It is important to investigate the injury mechanisms and injury levels that pregnant women may be subjected to in order to improve transport safety. The three dimensional computational model ‘Expecting’, which embodies a detailed multi-body model of a fetus in a finite element model of a uterus with a placenta, is developed at Loughborough University. The model is designed to simulate dynamic loading conditions that pregnant occupant may experience. In this study, ‘Expecting’ is used to study the kinematics of pregnant occupants to predict the injury levels to the pregnant driver in frontal crashes. The implications of ‘No restraint’, ‘Seat Belt Only’ and ‘Seat Belt & Airbag’ cases are investigated for various crash severities, from 15 to 45 kph. Crash analysis injury criteria such as Head Injury Criterion (HIC), 3ms maximum, Combined Thoracic Index (CTI) and Viscous Criterion (Max VC) are used. The results suggest that the frontal airbag together with the correctly worn seatbelt provide better protection for the pregnant drivers

Pregnant driver injury investigations in oblique crashes

Kinetics and kinematics of an oblique impact are different when compared to frontal collisions. The objective of this research is to simulate various oblique crash scenarios that pregnant drivers may experience by using the computational pregnant occupant model, ‘Expecting’ and investigate potential injuries that pregnant drivers may suffer. Half-sine acceleration pulses representing crash speeds 15kph to 45kph are used in the simulations. Oblique impact simulations are conducted both from the nearside and the farside (offside) of the vehicle. The placental abruption and hence fetus mortality risks during oblique crashes are compared with the full-frontal impact cases

Vehicle internal design improvement guidelines by using the computational pregnant occupant model 'expecting'

New interior designs for vehicles may improve the safety of pregnant occupants without compromising the safety of non-pregnant occupants. The objective of this study is to investigate the implications of the steering wheel unit orientation by using ‘Expecting’, the Computational Pregnant Occupant Model developed at Loughborough University. Three steering column angles and three steering wheel angles are modelled in a subcompact mini-car interior in MADYMO. A standard 3-point seat belt and an airbag are used as restraint systems. The strain values at the placental location of the uterus of ‘Expecting’ for frontal impacts with 15, 30, 45 kph are predicted for various steering wheel unit configurations and the resulting distance between the steering wheel unit and the abdomen and sternum of ‘Expecting’. Recommendations are made to improve safety

The effect of placenta location on the safety of pregnant driver and her fetus

Placental abruption accounts for more than half of fetal mortality in automobile collisions. In most of the pregnancies, placenta is located at the fundus position of the uterus. However, in real life, placenta can also be found at different locations in the uterus. The goal of this study is to investigate whether the location of the placenta in the uterus of pregnant driver has a role on the risk of placental abruption in motor vehicle accidents. In addition to the most common fundus position, four other placental locations, namely anterior, posterior, lateral left and lateral right, are considered within the computational pregnant driver model ‘Expecting’, and used in collision simulations with impact severities from 15 to 30 kph with 5-kph increments. Scenarios also include four cases where the pregnant driver is fully restrained with three-point seatbelt and airbag, three-point seatbelt only, airbag only and no restraint at all. The maximum strains developed in the utero-placental interface of the model in this set of 64 simulations together with the fundus-location simulations are determined and compared in order to investigate the effect of placental location on the placental abruption prediction. Placenta located at anterior position is found to be at higher risk than other placental positions considered in this investigation. The results demonstrate that being fully restrained is the safest option and the three-point seatbelt is the most effective restraint system whilst the airbag makes a small contribution to the protection of pregnant driver and her fetus

Effects of table design in railway carriages on pregnant occupant safety

This paper focuses on safety investigations for pregnant occupants, in particular, on their interactions with an interior feature, fixed bay tables, in railway vehicles. The computational pregnant occupant model Expecting has represented pregnant travellers in railway vehicle environments. Expecting is a computational pregnant occupant model developed at Loughborough University, in order to investigate the dynamic response of pregnant women to impacts. It has been successfully utilised by the authors in earlier studies, in various automobile crash investigations, such as frontal impacts with real and simplified crash pulses. In this study, a model of a network train carriage is generated and used together with Expecting to assess the suitability of fixed bay table designs for pregnant occupants. Investigations of potential injuries in this paper are believed to contribute to the design of more suitable interior features and hence improve safety and quality of life for pregnant women as travellers in railway vehicles

Seat belt designs to protect pregnant vehicle occupants

Various restraint systems to protect vehicle occupants in case of an accident have been specifically designed for pregnant women and the ideas are filed for patents. The concepts cover a wide range of designs; from ‘add-on’ to standard 3-point seat belt solutions to relatively complex mechatronics applications. Auxiliary tools and equipments to offer lap belt solutions constitute the majority of the reviewed patents. Designs also vary according to their working principles. Some designs exclusively focus on the lap belt part of the seat belt, whereas some others attempt to resolve the problem from a broader perspective, offering overall seat belt solutions with or without the use of standard seat belt. In this article around forty patented ideas on seat belt designs for pregnant women are reviewed, classified and presented, highlighting the working principles and inventors’ claims

Measurements for pregnant drivers' comfort and safety

Pregnant women experience many different problems and difficulties with comfort and safety during car travel, which can be alleviated by accommodating pregnant women's anthropometry. There has been a dearth of information about pregnant anthropometry and subsequently women's needs have been neglected. This paper addresses the problem by presenting a detailed analysis of the anthropometric changes occurring throughout the body. The measurements have been selected for use in the vehicle design process, in order to best meet the needs of the automotive industry. The paper investigates the size and shape changes in pregnant women to calculate the possible exclusion rates for designs based on male and non-pregnant female data in order to help improving pregnant drivers' safety and comfort. The paper points out the importance of changes not only in the abdomen but also the chest and hip regions