INDUCING OVERCONFIDENCE

In this study, I present a theory which explains how the influence of others may generate overconfidence. The argument is built on the idea that the more help an agent receives when performing a task, the less informative the score on that task will be relative to the agent's ability to perform it. If an agent is confident, he tends to benefit from more cooperation opportunities simply because he is likely to be perceived as being more skilled. As a result, he remains confident because the future signals he will observe will contain very little information regarding his ability. On the contrary, if the agent is not confident, he will receive more informative scores, which will help him learn his true ability faster. (JEL D81, D83, D84)     

Ergonomic factors and production target evaluation in eucalyptus timber harvesting operations in mountainous terrains

There are several forest operations involved in Eucalyptus timber harvesting. This study was carried out during brush-cutting; tree felling, bucking, delimbing, piling and manual extraction operations, with the following objectives: a) analyzing, ergonomically, two systems of brush-cutting: one manual and the other semi-mechanized, using two different machines; b) ergonomically evaluating three different brands of pruner machines used in delimbing felled trees. c) determining the feasible target of productivity as a function of ergonomic factors relevant to establish the time of resting pauses for workers in manual and semi-mechanized timber harvesting systems in mountainous terrain. Brush-cutting, either manual or semimechanized, is an activity carried out prior to timber harvesting. It is usually a hard work, with low productivity when compared with mechanized systems. Pruner machines have been used by forest companies, due to the great possibilities to improve productivity, quality and the health of workers. Ergonomics is a discipline that promotes the adequacy of work to the physical and mental characteristics of human beings, seeking to design production systems and products considering relevant aspects, including social, organizational and environmental factors. Companies should consider the ergonomic factor in the determination of daily worker production targets.     

Analysis on the relationship between the school furniture and the work surface lighting and the body posture of public Middle School students from João Pessoa, Paraíba, Brazil

The main objective of this study is to evaluate the impact of school furniture and work surface lighting on the body posture of two public Middle School students from Paraíba (Brazil). The target population included 8th grade groups involving 31 students. Brazilian standards for lighting levels, the CEBRACE standards for furniture measurements and the Postural Assessment Software (SAPO) for the postural misalignment assay were adopted for the measurements comparison. The statistic analysis includes analyses of parametric and non-parametric correlations. The results show that the students' most affected parts of the body were the spine, the regions of the knees and head and neck and about 90% of the students presented postural misalignment. The lighting levels were usually found below 300 lux, below recommended levels. Such results indicate the need of investments in more suitable school furniture and structural reforms aimed at improving the lighting in the classrooms, which could fulfill the students' profile and reduce their complaints.     

Body postures versus production requirements - the case of a fiberglass parts factory

This study aimed to perform an ergonomic analysis in a fiberglass parts factory. For this purpose, was used the methodology of Ergonomic Work Analysis (EWA). At the end of the study it was possible to identify some ways to the development of improvements in order to contribute to the transformation of working conditions in the sector analyzed.     

The importance of ergonomics in the design conceptual process: Daciano da Costa - a case study on practicing and teaching

This paper, which stems from a developing research project, aims to disseminate among the international scientific community the thought of Daciano da Costa (1930-2005) given the importance he conferred to Ergonomics, throughout his teaching career and his professional practice as a reference figure in the Design of the twentieth century in Portugal. We focus on the important role played by Ergonomics within the conceptual Design process, through the case study Daciano da Costa.What Daciano brought to the practice and teaching was a modernization of processes, a new perspective on the emerging themes of design, like ergonomics. Daciano believed that designing was providing a service. This task was understood as the building of a relationship with users. One of his distinguished features was the particular attention he paid to the unique aspects of the scale of proximity: the scale of the hand, of the immediate gesture, of the body. As a professor he insisted not so much on the end product, but rather on the recognition of the research process and how it was conducted. When designing, developing and supervising the exercises he set, ergonomic factors were one of his main concerns.     

Are cutout handles used when available in real occupational settings? Description of grips and upper extremities movements during industrial box handling

In order to achieve better postures and decrease musculoskeletal risks adequate design of hand/box couplings for manual materials handling (MMH) are still needed. No studies evaluating upper limb movement thorough direct measurements during box handling in workplace were identified in the literature. In this study we describe the types of grip and movements adopted by ten workers when handling redesigned boxes with cutout handles between different heights on industrial pallets. The new handles were used by 90% of the workers through different types of grip. Electrogoniometric measurements showed relatively safe forearm and wrist movements, although elbow inadequate range of movement was recorded. Despite the good acceptance of the cutout by workers, the new design requires extra internal space in the boxes reducing applications for this alternative of box.     

Proposal for training of workers and researchers as from the participatory return of research results in workers' health

This study streams from a perspective of Workers' Health as a field of intervention where worker's experience on the process of illness is essential to understand and generate changes in the work process, and to contribute to develop knowledge in this area. We intended to collaborate in the training of researchers and nursing workers as a means of contributing to amplify their knowledge related to work and health conditions. As a motto to promote dialogue between researchers and workers, we organized workshops to discuss the results of an epidemiological study on the work-health relationships in nursing. Ten workshops were conducted at two federal public hospitals, in the city of Rio de Janeiro, Brazil. The main aspects discussed during the workshops revealed (i) work nuances for which the questionnaire was not sufficiently sensitive, (ii) some associations between different aspects of the survey, dealt with in the questionnaires, and (iii) recognition that some aspects shown in the epidemiological results were experienced at work. One can appreciate that the proposal presented here contributed to the training of researchers and workers, amplifying their knowledge and contributing to the development of the activity.     

Ergonomics and design: traffic sign and street name sign

This work proposes a design methodology using ergonomics and anthropometry concepts applied to traffic sign and street name sign projects. Initially, a literature revision on cognitive ergonomics and anthropometry is performed. Several authors and their design methodologies are analyzed and the aspects to be considered in projects of traffic and street name signs are selected and other specific aspects are proposed for the design methodology. A case study of the signs of "Street of Antiques" in Porto Alegre city is presented. To do that, interviews with the population are made to evaluate the current situation of signs. After that, a new sign proposal with virtual prototyping is done using the developed methodology. The results obtained with new interviews about the proposal show the user satisfaction and the importance of cognitive ergonomics to development of this type of urban furniture.     

The use of thermal manikin to evaluate interface pressure distribution

The use of a thermal buttocks manikin was explored as a tool to standardize the evaluation of seat comfort. Thermal manikin buttocks were developed and calibrated thermally and anatomically to simulate the sensible heat transfer of a seated person and used to evaluate interface pressure distribution. In essence, the pressure maps of manikin buttocks with and without heating were compared to those of a seated person. The results of average pressure demonstrated that the thermal manikins have a better response in interface pressure measurement than manikins without heating.     

Comparing two types of navigational interfaces for Virtual Reality

Previous studies suggest significant differences between navigating virtual environments in a life-like walking manner (i.e., using treadmills or walk-in-place techniques) and virtual navigation (i.e., flying while really standing). The latter option, which usually involves hand-centric devices (e.g., joysticks), is the most common in Virtual Reality-based studies, mostly due to low costs, less space and technology demands. However, recently, new interaction devices, originally conceived for videogames have become available offering interesting potentialities for research. This study aimed to explore the potentialities of the Nintendo Wii Balance Board as a navigation interface in a Virtual Environment presented in an immersive Virtual Reality system. Comparing participants' performance while engaged in a simulated emergency egress allows determining the adequacy of such alternative navigation interface on the basis of empirical results. Forty university students participated in this study. Results show that participants were more efficient when performing navigation tasks using the Joystick than with the Balance Board. However there were no significantly differences in the behavioral compliance with exit signs. Therefore, this study suggests that, at least for tasks similar to the studied, the Balance Board have good potentiality to be used as a navigation interface for Virtual Reality systems.