Identifying subassemblies and understanding their functions during a design review in immersive and non-immersive virtual environments

Design review (DR) is a product development (PD) activity used to inspect the technical characteristics of a design solution. Immersive virtual reality (IVR) technology enables the presentation of spatial information and interaction with 3D CAD models inside an immersive virtual environment (IVE). Such capabilities have shown the potential to mitigate the cognitive load needed for the visual perception of spatial information and, consequently, enhance design understanding and DR performance. Thus, an increasing number of studies have explored the effect of IVR technology on DR activities in different domains. However, determining when the implementation of IVR technology rather than a conventional user interface for DRs in mechanical engineering PD projects will be beneficial remains unclear. Hence, a conceptual DR experimental study was conducted to investigate the differences in the ability of engineering students to identify mechanisms and understand their functions when a design solution for a technical system is presented in an IVE by IVR technology and in a non-immersive virtual environment (nIVE) by a conventional user interface (monitor display, keyboard, and mouse). Data were collected by performing DR tasks and having participants complete a prior experience questionnaire, presence questionnaire, and mental rotations test. Findings of the study indicate that IVR does not support an enhanced ability of engineering students to identify mechanisms and understand their functions compared with a conventional user interface.     

Reduction of the effect of aberrations in a joint-transform correlator

We report the study of the influence of optical aberrations in a joint-transform correlator: The wave aberration of the optical system is computed from data obtained by ray tracing. Three situations are explored: We consider the aberration only in the first diffraction stage (generation of power spectrum), then only in the second (transformation of the power spectrum into correlation), and finally in both stages simultaneously. The results show that the quality of the correlation is determined mostly by the aberrations of the first diffraction stage and that we can optimize the setup by moving the cameras along the optical axis to a suitable position. The good agreement between the predicted data and the experimental results shows that the method explains well the behavior of optical diffraction systems when aberrations are taken into account.     

Optimized Convolutional Neural Network Models for Skin Lesion Classification

Skin cancer is one of the most severe diseases, and medical imaging is among the main tools for cancer diagnosis. The images provide information on the evolutionary stage, size, and location of tumor lesions. This paper focuses on the classification of skin lesion images considering a framework of four experiments to analyze the classification performance of Convolutional Neural Networks (CNNs) in distinguishing different skin lesions. The CNNs are based on transfer learning, taking advantage of ImageNet weights. Accordingly, in each experiment, different workflow stages are tested, including data augmentation and fine-tuning optimization. Three CNN models based on DenseNet-201, Inception-ResNet-V2, and Inception-V3 are proposed and compared using the HAM10000 dataset. The results obtained by the three models demonstrate accuracies of 98%, 97%, and 96%, respectively. Finally, the best model is tested on the ISIC 2019 dataset showing an accuracy of 93%. The proposed methodology using CNN represents a helpful tool to accurately diagnose skin cancer disease.     

Phase-Change Characteristic Analysis of Partially Melted Sodium Acetate Trihydrate Using DSC

Sodium acetate trihydrate (SAT), which is a kind of phase-change material, offers high potential for application in thermal energy storage. However, SAT has a natural tendency to supercool during its solidification process. Adding nucleating agents has been suggested as a possible solution. In this paper, the phase-change characteristics of the partially melted SAT were analyzed using a differential scanning calorimeter (DSC). A phenomenon related to SAT undergoing phase change was discovered and analyzed. The results showed that if SAT were cooled when it was partially melted, it would release heat and quickly solidify without adding any nucleating agents. Therefore, if the temperature range of SAT was controlled properly, supercooling could be significantly prevented.     

Pedestrian preferences with respect to roundabouts—A video-based stated preference survey

Research on user behavior and preferences has been a helpful tool in improving road safety and accident prevention in recent years. At the same time, there remain some important areas of road safety and accident prevention for which user preferences, despite their importance, have not been explored. Most road safety research has not explicitly addressed vulnerable user (pedestrians and cyclists) preferences with respect to roundabouts, despite their increasing construction around the world. The present research stems from the fact that studies related to roundabout safety have generally focused on drivers, while overlooking the importance of safety as it relates to vulnerable users, especially pedestrians. Moreover, it handles this particular issue through an approach that has not been used so far in this context; the Stated Preference (SP) survey. As such, there are two main goals (and contributions) of this work. First, to show how SP surveys can be used to investigate the importance of different design and operational features to pedestrian perceptions of safety in roundabouts. This allows us, for example, to quantify how some features of roundabouts (e.g. high traffic volume) can be compensated for by design features such as pedestrian islands. This is useful in helping to design roundabouts that pedestrians prefer and will hopefully use, to help encourage active transport. Second, to demonstrate how traffic simulation software can be successfully used to include difficult-to-communicate attributes in SP surveys.     

Effectiveness of cable barriers,guardrails, and concrete barrier walls in reducing the risk of injury

Roadway departure crashes tend to be severe, especially when the roadside exposes the occupants of errant vehicles to excessive injury hazards. As a cost-effective method when the clear zone width is insufficient, road barriers are often installed to prevent errant vehicles from colliding with dangerous obstacles or traversing steep slopes. This paper focuses on the safety performance of road barriers in Indiana in reducing the risk of injury. The objective of the study presented here is to compare the risk of injury among different hazardous events faced by an occupant in a single-vehicle crash. The studied hazardous events include rolling over, striking three types of barriers (guardrails, concrete barrier walls, and cable barriers) with different barrier offsets to the edge of the travelled way, and striking various roadside objects.     

Exploring a cobot risk assessment approach combining FMEA and PRAT

Collaborative robots are an emerging technology falling within the scope of Industry 4.0 and based on the concept of Human-Robot Collaboration (HRC). Unlike traditional industrial robots, collaborative robots are used in shared workspaces with no safety fences. Hence, prospective hazardous contacts need to be avoided or mitigated through a risk assessment. The normative standards such as ISO TS 15066 suggest a list of common hazards, but do not guide the robot system user through the risk assessment process. To address this shortcoming, this paper proposes a practical eight steps risk assessment approach, resulting in a risk priority list. In order to provide an accurate, practical, quantitative and supportive tool for HRC environments, the Failure Mode and Effects Analysis (FMEA) and the Proportional Risk Assessment technique (PRAT) techniques are proposed for risk assessment. The two techniques mentioned above are combined in the suggested new methodology, highlighting both their benefits and disadvantages. The proposed methodology is applied with positive results to a collaborative brick-lifter case study.     

Parent, family, and disease factors as predictors of psychosocial functioning in children with cystic fibrosis.

Examined the relative contribution of disease, parental, and family factors on the psychological and social functioning of children with cystic fibrosis. 33 patients (7–16 yrs old) and 29 mothers completed a battery of tests, including a state-trait anxiety inventory, the Beck Depression Inventory, and a coping health inventory for parents developed by H. I. McCubbin et al (1983). Results show that Ss' self-esteem and occurrence of behavioral problems were associated with maternal trait anxiety, overprotection, and the impact of disease on family functioning. Social competence and athletic self-esteem were associated with nutritional status. Results reflect the need for clinicians to be sensitive to parental and family functioning when dealing with behavioral problems and to consider physical status when providing treatment of social problems. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)