Catálogo de publicaciones - libros

The relationship between the properties of flexible polyurethane foam composing seat cushions for standard cars and the riding discomfort evaluated by subjects who sat on the seat were investigated. The properties of five kinds of polyurethane foam were measured using the DMA to define dynamical properties. Riding discomfort was subjectively evaluated by 17 subjects at four frequencies, and the correlation coefficients between the material properties and riding discomfort were analyzed. The results suggested that there were two relationships between material properties and riding discomfort, and that these relationships strongly relied on frequency. Furthermore, a digital human model was created to confirm the influence of frequency on these relationships, which suggested that the relationships affected sensitivity by the change in the vibration mode of the human body-seat vibration system.

This paper discusses the impact of human interaction with biometric devices and its relationship to biometric performance. The authors propose a model outlining the Human-Biometric Sensor Interaction and discuss its necessity through case studies in fingerprint recognition, hand geometry, and dynamic signature verification to further understand the human-sensor interaction issues and underlying problems that they present to the biometric system. Human factors, human-computer interaction and digital human modeling are considered in the context of current and future biometric research and development.

This paper emphasized on how to construct one kind of assessment system based on the standards and specifications for cockpit ergonomic synthesis assessment, and the knowledge of the aviation experts and the experienced pilots. It analyzed the necessity of developing the assessment system, and then presented the basic principal and the function demand of the assessment system. In addition, the key technologies for developing this assessment system were discussed in detail utilizing Visual FoxPro 6.0. This assessment system transforms the assessment model and process into the computer program by the mathematical model, enables the assessment process truly to be operational, and also can reduce the assessment cycle.

The study of pilot perception has evolved from examining simple tasks executed in reduced laboratory conditions to the examination of complex, real-world behaviors. A test-bed for evaluating models of pilot behavior in which a set of infrared video-based eyetrackers to monitor subjects’ eye movements while they perform a range of complex tasks such as driving, and manual tasks requiring careful eye-hand coordination was developed. The real cockpit platform is provided to subjects as they pilot in a virtual scene; a dual-haptic interface consisting of two touch-screen display devices and a shift allows free control within the cockpit.

The EVA spacesuit glove is one of the key components which can assure astronauts to achieve EVA tasks in security. Astronauts are subjected to the influence of low temperature when they are performing tasks outside the spaceship. To establish the standard of the ergonomics of the temperature of the glove work is very important. This paper studies the influence of low temperature on the ergonomics of the glove work when the skin surface temperature of the middle fingertip is at normal temperature, 15.6C and 10C respectively, in which the strength, fatigue, sensibility and flexibility are made as evaluation targets. The experiment indicates: the influence on the ergonomics of glove is not obvious when the temperature is controlled at 15.6C. Therefore the temperature of the middle fingertip skin should be controlled above 15.6C in glove design; the influence to the ergonomics of glove is relatively obvious when the temperature is about 10C. The influence on sensibility is the most obvious, and then the influence on fatigue, strength and flexibility is in descending order. The temperature standards of EVA spacesuit glove have practical meaning to design EVA spacesuit.

This paper studies the use of Virtual Reality and Human Simulation for the ergonomic evaluation of manual assembly processes. A virtual environment has been developed to represent the actual workspace where the assembly task took place. Into the virtual workspace, a digital human /mannequin was imported and programmed to simulate the task, in the same manner as it would be done by the actual worker. Based on the posture-based ergonomics analysis, each posture of the digital human has been “translated” into comfort scores, resulting in conclusions, related to the ergonomic efficiency of the process and in the design of the workstation. The conclusions that have been reached identify the critical points, during the assembly task, and lead to the necessary re-design actions in order for the worker’s fatigue as well as the task’s execution time to be reduced. A real-life assembly task of a commercial refrigerator has been implemented in order for the capabilities of the proposed process design evaluation method to be demonstrated.

The aim of the present work was to gather data concerning the measurements and the shape of individuals’ feet of Italians, to design more ergonomic shoe lasts. The unloaded feet of a sample of 316 participants of Italian ethnicity of 20 different towns located in northern, central, and southern Italy and the Italian islands were digitalized. Results showed significant differences by gender, age, and geographical area. The sample’s degree of awareness concerning some of their own foot characteristics and interaction with footwear were also investigated. These findings will be used to design footwear that can provide a good fit for the feet of Italians and, consequently, a greater degree of comfort.

Inspection quality is dependent on the ability of inspectors to weed out defective items. When inspection is visual in nature, humans play a critical role in ensuring inspection quality with training identified as the primary intervention strategy for improving inspection performance. However, for this strategy to be successful, inspectors must be provided with the needed tools to enhance their inspection skills. In this article we outline efforts pursued at Clemson University, focusing on the development of computer-based training systems for inspection training and discuss the results of some of the research briefly.

As the foundation of user-system interaction in virtual environments, collision detection is a time-consuming process and few real-time interactive algorithms for general objects developed. Most of the existing methods aim for reducing the computation time for some special cases. Collision detection algorithms developed are either not fast enough for practical applications or restricted to a class of specific model. In fact, a general analysis of the performance of collision detection algorithms is extremely difficult because performance is situation specific. The motivation of this work is to satisfy the real-time interaction and high precision requirements of a Virtual Environment (VE) for applications such as virtual design, virtual assembly, virtual training for manufacturing operations and maintenance.

Human-populated VR models have been employed by many researchers to evaluate workspace occupational health and safety (OHS) problems. Previous researches in VR-based ergonomic evaluation have taken a model-based, quantitative approach where human posture data are extracted from virtual space and sent to ergonomic models to calculate numeric results. Such model-based approach requires the VR model to be integrated with complex human models and ergonomic evaluation models. Construction of the virtual workspace thus becomes complicated and difficult, which often stops industrial adoption of the VR technology in ergonomic evaluation. To address this problem, this paper presents an easy-to-construct human-populated VR model to support visualization-based, qualitative workspace OHS evaluation. Details of the workspace layout design and the operation procedure design, and the dynamic VRML modeling to support the workspace design are discussed. Based on the proposed method, a human-populated virtual workspace is implemented to evaluate OHS problem associated with the design of a ship operation room.