Ergonomic work analysis of airbus pilots job in Brazil

This article is the result of a case study of ergonomic work analysis carried out in a Brazilian airline company, focused on the safety of the activity of Airbus pilots from the company's national lines. The study was divided in three parts, each one with different approach. First step is how critical situations such as accidents and incidents are dealt with during flight. Then it comes to discuss about adversities found in the working place, the airbus cockpit, and the development of risk map. Last but not least, the study focused in how the irregular working journey compromises the biological clock of the pilots end may cause social issues.     

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.     

Invisible computer for collaborative design: evaluation of a multimodal sketch-based environment

In the areas of design, especially in architectural design, collaboration has become an important challenge. The specialization of skills increase, work teams are more and more extensive and the geographic distance between them increases too. The economic and ecological stakes related to remote collaboration are an evidence. This context involves the need to support most efficiently possible remote working meetings. We present the Distributed Collaborative Digital Studio (DSDC), a tool designed to recreate, in distant situations, the context of copresence meetings. This shared environment is created in the "invisible computer" approach [11]. The idea is that the tool should disappear from user's consciousness. Indeed, creative design activities require some fluidity in their process. Therefore, any involuntary interruption created by the system can potentially brake creativity. In this perspective, we investigate specifically the "invisibility" of our environment. To do this, we propose a framework for the operationalization of the concept and a methodology to test the system invisibility. This methodology was applied through a case study consisting of a corpus of 12 hours of remote collaborative design sessions with the DSDC. We highlight the learning effects while using our system, conclude on its effectiveness and discuss our methodology.     

Operative strategies of HLB's scouts of a citrus property within the State of Sao Paulo, Brazil

This research aimed to study the activity of the HLB's scouts, workers whose function is to identify symptomatic plants, in order to understand the physical constraints, cognitive and organizational involved in accomplishing the task, characterizing the operative approach used to identify diseased plants, and to elucidate what aspects hinder the identification of symptoms. The method adopted for the research was the Ergonomic Analysis of Work--EAW [6]. The results, after validation with the operators and management, allowed understanding the complex relationships between the physical, cognitive and organizational aspects present on activity. Major difficulties were observed mainly in relation to the disposal of the scouts on the platforms and in relation to working hours, at the beginning and end of the journey. Important findings have highlighted strategies, unknown by the organization, used by scouts to locate candidates' trees to the fine analysis of investigation of symptoms. In conclusion, the analysis enable to understand the constraints and find technical and organizational solutions to the survey work on citrus groves as well as it showed signs and symptoms not investigated yet or rarely considered by researchers involved on searches aimed at increasing the ability to diagnose the disease in the field.     

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.     

From needs to requirements for computer systems: the added value of ergonomics in needs analysis

It is widely recognised that ergonomists must contribute during needs analysis. However, few studies have investigated the specific contributions of ergonomists at this stage of the design process. In this study, this contribution is studied through the requirement document produced by the design team. For each requirement, the source (i.e. who formulated the requirement), justification (why the requirement is needed), type (functional, interaction, operational, physical, organizational), and scope (entire system or part thereof) were analysed. Results indicate that the various actors are complementary and work collectively to define the various dimensions of the system. With end-users, the ergonomist worked on the global aspects of the system: function, conditions of use and organizational dimension. Alone, he defined the global interaction of the system. The various functions derived from the global function were defined in collaboration with engineers. However, while engineers contributed to defining how these functions would work, as well as their technical conditions of use, the ergonomist focused on their purpose, and, with end-users, on their organizational aspects. Finally, results suggest that neither the ergonomist's specific knowledge in ergonomics, nor work analysis were sufficient to derive his requirements; both are mandatory.     

Collaboration, (Dis)trust and Control in Brazilian Manufactured Public/Non-profit Partnerships

This study seeks to evaluate whether interorganizational trust and interpersonal trust influence the nature of state control in Brazilian public/non-profit partnerships (PNPs) by considering the social organization model with a non-profit partner that did not evolve organically from civil society as an equal and interdependent partner but instead was engineered by the state. We conducted qualitative research on two PNPs and analysed their historical trajectories through participant observation, documentary analysis and semi-structured interviews with the state and non-profit partners as well as other actors involved indirectly in the PNPs. Our findings call into question the assumption of current studies that trust tends to be built over time and reveal that PNPs embedded in state-dominant and low-social-capital contexts are more vulnerable to the effects of interpersonal trust. This vulnerability influences the volatile patterns of the PNPs’ trajectories and leads to strong informal state-partner control as reflected by PNP disruptions and lower levels of interorganizational trust.

     

Non-linear regression models for Approximate Bayesian Computation

Approximate Bayesian inference on the basis of summary statistics is well-suited to complex problems for which the likelihood is either mathematically or computationally intractable. However the methods that use rejection suffer from the curse of dimensionality when the number of summary statistics is increased. Here we propose a machine-learning approach to the estimation of the posterior density by introducing two innovations. The new method fits a nonlinear conditional heteroscedastic regression of the parameter on the summary statistics, and then adaptively improves estimation using importance sampling. The new algorithm is compared to the state-of-the-art approximate Bayesian methods, and achieves considerable reduction of the computational burden in two examples of inference in statistical genetics and in a queueing model.     

Low wages and high unemployment rates: The role of social interactions in hiring discrimination

The purpose of this paper is to explain why low-wage workers with identical qualifications to higher-wage workers are more exposed to unemployment. Each worker is considered to belong to a social group (defined according to his/her gender, age, and nationality). We assume that workers experience both productive interdependencies and social interactions within the firm. Also inter- and intra-group interactions determine worker productivity, and frictions on the labor market limit the hiring of the most productive workers. Consequently, externalities acting both within the firm and in the labor market can lead to a higher rate of unemployment for low-wage workers.