Mixed linear regression with equi-cross-correlated errors

Received: August 12, 1999; revised version: April 3, 2000     

Interaction between employees' physical load factors and early support at the workplace

Physical workload is a continuous problem, even in modern workplaces. The purpose of the survey was to determine the effect of support on employees' physical load factors at workplaces. Training, guidance and support were the main focus areas of the early support intervention, which aimed to enable supervisors to find weak signals of impaired ergonomics.The survey was carried out in the form of a controlled longitudinal study, and the material was gathered via a questionnaire in both 2008 and 2010 from two co-operative trade groups. The final sample was 301 intervention subjects and 235 control subjects, and the response rate was 45% in both groups. We applied factor analysis to reduce the number of items. The physical load factors' sum score consisted of six items. We used logistic regression in the statistical analysis.Encouragement to improve processes at the workplace increased the probability of positive change (i.e. decrease) in physical load factors. The same applied to working pace, if individuals could control it themselves. In contrast, workload and the support of supervisors had a reversed impact on workers' physical load factors. Focusing on promoting workers' ergonomics is still important in workplaces when aiming to decrease physical load factors.     

Physical workload and thoughts of retirement

The aim of this paper is to present Finnish employees' opinions on continuing work until retirement pension and after the age of 63, and to find out if physical workload is related to these opinions. Altogether 39% of men and 40% of women had never had thoughts of early retirement, and 59% claimed (both men and women) that they would consider working beyond the age of 63. Own health (20%); financial gain such as salary and better pension (19%); meaningful, interesting and challenging work (15%); flexible working hours or part-time work (13%); lighter work load (13%); good work community (8%); and good work environment (6%) were stated as factors affecting the decision to continue working after the age of 63. Employees whose work involved low physical workload had less thoughts of early retirement and had considered continuing work after the age of 63 more often than those whose work involved high physical loads. Own health in particular was stated as a reason to consider continuing work by employees whose work was physically demanding.     

Finding disturbances in on-farm biogas production

When implementing innovations, disturbances are very likely to take place. Disturbances are undesirable because they can lead to unwanted outcomes, such as economic losses and work overload to workers. However, they can be powerful opportunities for learning and re-designing innovations. Here, we will present activity theoretical tools for analyzing disturbances in a way that they could be used as learning opportunities. We illustrate the proposed tools by analyzing a disturbance that took place during the implementation of a project of biogas production. By interpreting the disturbance process with a network of activity systems, we found that on-farm disturbances were formed as ruptures, innovations and asynchronies originated in other activity systems. This finding suggests that disturbances are outcomes of the functioning of networks, rather than simple results of failure of individuals or technical devices. The proposed tools could be used in interventions to help practitioners and ergonomists to recognize the systemic and networked nature of problems, and therefore, realize that they may require the collaboration of actors from different activities. In this sense, disturbances may be turned into opportunities for learning and developing innovations. We conclude by discussing how the method could be used in ergonomic design and intervention.     

Digital test assembly of truck parts with the IMMA-tool--an illustrative case

Several digital human modelling (DHM) tools have been developed for simulation and visualisation of human postures and motions. In 2010 the DHM tool IMMA (Intelligently Moving Manikins) was introduced as a DHM tool that uses advanced path planning techniques to generate collision free and biomechanically acceptable motions for digital human models (as well as parts) in complex assembly situations. The aim of the paper is to illustrate how the IPS/IMMA tool is used at Scania CV AB in a digital test assembly process, and to compare the tool with other DHM tools on the market. The illustrated case of using the IMMA tool, here combined with the path planner tool IPS, indicates that the tool is promising. The major strengths of the tool are its user friendly interface, the motion generation algorithms, the batch simulation of manikins and the ergonomics assessment methods that consider time.     

Care workers, care drain, and care chains: reflections on care, migration, and citizenship

In this article, we discuss a case study that deals with the care chain phenomenon and focuses on the question of how Poland and the Ukraine as sending countries and Poland as a receiving country are affected and deal with female migrant domestic workers. We look at the ways in which these women organize care replacement for their families left behind and at those families’ care strategies. As public discourse in both countries is reacting to the feminization of migration in a form that specifically questions the social citizenship obligations of these women, we also look at the media portrayal of the situation of nonmigrating children. Finally, we explore how different aspects of citizenship matter in transnational care work migration movements.     

Jokes and routines make everyday life a good life—on ‘doing family’ for young people in foster care in Sweden

The aim of this article is to identify inclusion practices in foster families by studying the everyday life of young people entering various types of foster family. Structure and warmth in the family stand out as important dimensions of everyday life. What is not so evident in previous research is the way emotional ‘warmth’ is created. In particular, joking, gentle teasing and laughing, which in this paper stand out as important inclusion practices, seem to be rather unknown aspects in foster care, as is the importance of doing things together in everyday life. The young people's contributions in creating a good family atmosphere are visible in the study, as is their capacity to adapt to a new family. Daily routines normalise the adolescents' everyday life. Negotiations make them part of important decisions, and may strengthen them as social agents. Foster parents' positive attitude towards birth family facilitates birth parents' support to their children. In this case study, mixed qualitative methods are used: interviews, network maps, ‘beepers’ and video recordings in the foster home.