Determinants of traffic injuries in drivers and motorcyclists involved in an accident

Basic information on the risk factors of road traffic injuries in Iran is scarce. This case-control study was conducted to determine the association of potential risk factors with the incidence of injury among motor vehicle drivers and motorcyclists on Qazvin-Loshan Road. The cases were 175 drivers and motorcyclists who had a road traffic accident (RTA) and sustained an injury. The controls were 175 motorists who had a RTA, on the same road and over the same time period, without suffering any injury. The analyses were separately performed by comparing the controls with mildly and severely injured cases, using New Injury Severity Score (NISS) 15 as a threshold. The results showed that fire following collision was significant in the crude analysis of all 175 cases and controls. The severity of collision, vehicle type (motorcycle versus other vehicle crashes), and gender were significant in the multivariable analyses of both mildly and severely injured cases. Safety equipment use is only significant (adjusted odds ratio, AOR=0.44, 95% confidence interval, 95%CI=0.23-0.84) among mild cases. The number of collisions (AOR=3.87, 95%CI=1.64-9.10) and weather conditions (AOR=4.32, 95%CI=1.13-16.5) only associate significantly with the occurrence of road traffic injury in severe cases, in comparison with the controls.     

Wireless Technologies in Healthcare: Selected Papers from IEEE PIMRC 2011

The use of wireless technologies for medical device communication, health monitoring (at hospitals or homes) and mobile healthcare information delivery (i.e. m-Health) is one of the most rapidly growing areas in health-IT research today. The papers which appear in this special issue have been carefully selected from the best IEEE PIMRC 2011 conference. They are highlighting various challenging issues in using wireless technology for healthcare applications such as PHY & MAC innovations for wearable and implantable medical sensors, optical communication and location systems in hospital environments and interference mitigation issues.     

Multidisciplinary wing design optimization considering global sensitivity and uncertainty of approximation models

In recent years, high-fidelity analysis tools, such as computational fluid dynamics and finite element method, have been widely used in multidisciplinary design optimization (MDO) to enhance the accuracy of design results. However, complex MDO problems have many design variables and require long computation times. Global sensitivity analysis (GSA) is proposed to assuage the complexity of design problems by reducing dimensionality where variables that have low impact on the objective function are neglected. This avoids wasting computational effort and time on low-priority variables. Additionally, uncertainty introduced by the fidelity of the analysis tools is considered in design optimization to increase the reliability of design results. Reliability-based design optimization (RBDO) and possibility-based design optimization (PBDO) methods are proposed to handle uncertainty in design optimization. In this paper, the extended Fourier amplitude sensitivity test was used for GSA, whereas a collaborative optimization-based framework with RBDO and PBDO was used to consider uncertainty introduced by approximation models. The proposed method was applied to an aero-structural design optimization of an aircraft wing to demonstrate the feasibility and efficiency of the developed method. The objective function was to maximize the lift-to-drag ratio. The proposed process reduced calculation efforts by reducing the number of design variables and achieved the target probability of failure when it considered uncertainty. Moreover, this work evaluated previous research in RBDO with MDO for the wing design by comparing it with the PBDO result.     

Modeling of particle deposition in a vertical turbulent pipe flow at a reduced probability of particle sticking to the wall

Particle deposition on the wall in a dilute turbulent vertical pipe flow is modeled. The different mechanisms of particle transport to the wall are considered, i.e., Brownian motion, turbulent diffusion and turbophoresis. The Saffman lift force, the electrostatic force, the virtual mass effect and wall surface roughness are taken into account in the model developed. A boundary condition that accounts for the probability of particle sticking to the wall is suggested. An analytical solution for deposition of small Brownian particles is obtained. A particle relaxation time range, where the model developed is reliably applicable, is evaluated. Computational results obtained at different particle-wall sticking probabilities in the wide particle relaxation time range are presented and discussed.     

Perceptions of the taste of colors in children and adults

Taste is an acquired phenomenon. The tastes of colors are related to people's perceptions and assumptions, as well as their personal experiences. In other words, there is a meaningful correlation between taste and color. However, this correlation requires extensive investigation before general patterns of taste perceptions can be determined. In addition, multiple studies of a range of different populations are necessary. This study investigated the responses of 56 male and 56 female Iranian participants aged 2 to 6 years to 11 colors commonly used in food and food packaging. Data analysis revealed significant correlations between perceptions of the taste of colors and the relationships between primary and secondary colors in Itten's color wheel. The data were also compared with data from an earlier and identical survey of the taste perceptions of adult Iranians. Participants in both groups perceived the taste of secondary colors as the taste common to their two constituent primary colors. In addition, the basic color rules set out in Itten's color wheel in relation to secondary and achromatic colors also affected how the taste of each color was perceived.     

Viscoelastic properties of architected foams based on the Schoen IWP triply periodic minimal surface

Abstract

In this article, we studied the viscoelastic properties of an architected foam based on the mathematically-known Schoen IWP triply periodic minimal surface (TPMS) under both time and frequency domains. IWP-based architectures possess unique multifunctional attributes when used as a three-dimensional (3D) reinforcement in composites. The 3?D representative volume elements (RVEs) of different relative densities (i.e., the ratio of the foam’s density to the density of its solid counterpart) were generated and studied using the finite element method in order to predict the effective uniaxial, shear, and bulk viscoelastic responses of IWP-foams as a function of relative density and/or frequency. The principle of time-temperature superposition principle was used to create the master curve of the observed relative-density dependent mechanical responses (loss tangent, storage and loss moduli) in frequency domains. Reduced uniaxial, bulk, and shear stiffness-loss map results suggested that the IWP-foam possesses strongest uniaxial viscoelastic response while highest damping can be achieved under shear responses. Relaxation behavior of IWP-foam was compared with other six different types of open-cell periodic foams. It was found that IWP-foam uniaxial response is similar to simple cubic foam, bulk relaxation response is similar to primitive-foam while shear response follows the behavior of body centered cubic foam. Among these foams, we found that IWP-foam is the best candidate to use as a damper under uniaxial and hydrostatic loading conditions.     

Production Lot-Sizing Under Learning Effects: An Efficient Solution Technique

In this paper, we consider a production-inventory model which assumes that learning occurs as a function of the number of units produced. We analyze two cases: the first case allows for no forgetting between production runs and the second case (a generalization of the first case) allows for some given degree of forgetting between production runs. In the first case, we show that learning only has an impact on initial lot-sizes for large order quantities and that steady state lot-sizes will approach the traditional EOQ amount. In addition, we show that succeeding lot-sizes are always nonincreasing. Applying these results to the second case when forgetting occurs, we develop efficient heuristic algorithms with complexity O(N logN) to determine order quantities. Results from our algorithms are compared to optimal solutions; these comparisons indicate that our algorithms usually provide solutions within one percent of the optimal cost.