Noise analysis in professional office chairs

The noise caused by the movement of users on their chairs in the work environment may indicate structural weaknesses and risk, and still significantly reduce productivity by increasing employees stress level. By understanding the activities to be developed in a work place one may understand what should be necessary to a good development, thereafter a search for improvement of labor activity with the aim of better use of resources in the operation of product use may be done. The analysis of the incremental variation of noise in professional chairs aims to identify its origin and the time the emission of noise starts during the period of use, its development and the major causative agents. Determining the characteristics of the sound of different materials and adjustments mechanisms of the chair can determine how different materials interact with each other. The measurement of these noises in an acoustic isolated room using directional microphones, if recorded and analyzed properly makes it possible to investigate and orientate to suspect elements in order to propose solutions and identify the quality of other similar chairs. Based on the results recommendations can be established for the orientation of users, managers and people responsible for the acquisition of the products, inducing them to review the employment of materials and the choice of the processes of production. These aspects are not covered in the Brazilian ergonomics norms and standards in the use of chairs.     

The reality of the women who make our lives easier: experience in a company that assemblies electric motors in Venezuela

Objective: intervene a workline throughout ergonomic approach to diminish incidence of Carpal Tunnel Syndrome (CTS). Methods and Materials: an ergonomic intervention study was developed in workstations with highest index of musculoskeletal disorder (MED) associated to cumulative trauma. The Deparis method, Reba and Ocra check list methods were used, also morbility reviewes. National and international ethics criteria were carried out. Results: workers identified 3 fundamental issues using the Deparis method: repetitive activities, postures adopted and uncomfortable furniture. The analysis of the workstation with Reba and Ocra methods before the changes, evidenciated that 56% of postures adopted were high risk postures, the 44% remaining were medium and low-risk. Following the active pause program (APP), furniture changes and work rhythm decrease, was noted that the risk of suffering MED decreased. The morbility review, drop in consults of musculoskeletal system (MES) related to CTS observed. The APP was well accepted by women, but not initially men. Discussion: the research show that when the work rhythm decreases, the symptom of MES related to CTS have a remarkable decrease, also that changes in the furniture, generate great ergonomic differences and changes in the work environment are not possible if workers don't empower the tools to make-it.     

A usability gap between older adults and younger adults on interface design of an Internet-based telemedicine system

Internet-based telemedicine is becoming an effective tool to deliver home-healthcare services and health information on demand, especially in rural areas, where there is often a large elderly population with greater rates of preventable chronic diseases. However, the designs of current interfaces for these internet-based telemedicine systems do not take elderly user characteristics into consideration. This study conducted usability testing on the interface of an internet-based telemedicine system using two different age groups, young adults and older adults. Differences in overall performance and satisfaction between the two groups were identified. Based on these results, a future direction is suggested for the interfaces of Internet-based telemedicine systems.     

The amount of ergonomics and user involvement in 151 design processes

Ergonomics, usability and user-centered design are terms that are well known among designers. Yet, products often seem to fail to meet the users' needs, resulting in a gap between expected and experienced usability. To understand the possible causes of this gap the actions taken by the designer during the design process are studied in this paper. This can show whether and how certain actions influence the user-friendliness of the design products. The aim of this research was to understand whether ergonomic principles and methods are included in the design process, whether users are involved in this process and whether the experience of the designer (in ergonomics/user involvement) has an effect on the end product usability. In this study the design processes of 151 tangible products of students in design were analyzed. It showed that in 75% of the cases some ergonomic principles were applied. User involvement was performed in only 1/3 of the design cases. Hardly any correlation was found between the designers' experience in ergonomic principles and the way they applied it and no correlations were found between the designers' experience in user involvement and the users' involvement in the design process.     

Health,wartime stress,and unit cohesion: Evidence from Union Army veterans

We find that Union Army veterans of the American Civil War who faced greater wartime stress (as measured by higher battlefield mortality rates) experienced higher mortality rates at older ages, but that men who were from more cohesive companies were statistically significantly less likely to be affected by wartime stress. Our results hold for overall mortality, mortality from ischemic heart disease and stroke, and new diagnoses of arteriosclerosis. Our findings represent one of the first long-run health follow-ups of the interaction between stress and social networks in a human population in which both stress and social networks are arguably exogenous.     

Knox meets Cox: Adapting epidemiological space-time statistics to demographic studies

Many important questions and theories in demography focus on changes over time, and on how those changes differ over geographic and social space. Space-time analysis has always been important in studying fertility transitions, for example. However, demographers have seldom used formal statistical methods to describe and analyze time series of maps. One formal method, used widely in epidemiology, criminology, and public health, is Knox’s space-time interaction test. In this article, we discuss the potential of the Knox test in demographic research and note some possible pitfalls. We demonstrate how to use familiar proportional hazards models to adapt the Knox test for demographic applications. These adaptations allow for nonrepeatable events and for the incorporation of structural variables that change in space and time. We apply the modified test to data on the onset of fertility decline in Brazil over 1960–2000 and show how the modified method can produce maps indicating where and when diffusion effects seem strongest, net of covariate effects.     

Population and pavement: population growth and land development in Israel

This research examines land use change in Israel––an intriguing but understudied setting with regard to population–environment dynamics. While Israel is fairly unique with regard to its combined high levels of economic prosperity and high population growth, this case study has relevance for developed countries and regions (like the south and southwest regions of the USA) which must balance population growth and urban development with open space conservation for ecosystem services and biological diversity. The population–land development relationship is investigated during the period from 1961 to 1995 at three spatial scales: national, regional (six districts), and local (40 localities). There is a positive correlation between population growth and land development rates at the national scale, and while remaining positive, the strength of the relationship varies greatly at regional and local scales. The variation in population–land use dynamics across scales is used to garner insight as to the importance of geography, policy and historical settlement patterns.     

Environmental Influences on Well-Being: A Dyadic Latent Panel Analysis of Spousal Similarity

This article uses dyadic latent panel analysis (DLPA) to examine environmental influences on well-being. DLPA requires longitudinal dyadic data. It decomposes the observed variance of both members of a dyad into a trait, state, and an error component. Furthermore, state variance is decomposed into initial and new state variance. Total observed similarity between members of a dyad is decomposed into trait similarity, initial state similarity, new state similarity, and error similarity. Dyadic similarity in new state variance reveals that both members of a dyad change in the same direction, which is a strong indication of environmental effects. DLPA is used to examine environmental influences on life satisfaction and domain satisfaction based on 22 annual assessments of married couples in the German Socio-Economic Panel Study (N’s = 607–740). The results show high similarity in new state variance for life satisfaction and objectively identical domains (household income, housing), and less similarity for objectively less similar domains (recreation, health). This finding provides strong evidence for environmental influences on well-being. In addition, the results show high trait similarity. The implications of the latter finding for interpretation of behavioral genetics studies of well-being are discussed.     

Binge drinking and labor market success: a longitudinal study on young people

This paper presents a two-equation model of joint outcomes on an individual’s decision to binge drink and on his/her annual labor market earnings. The primary data source is the 1979 cohort of the National Longitudinal Survey of Youth (NLSY79), 1979–1994. We show that binge drinking behavior is quite alcohol-price responsive and is a rational addiction. A new result is that an individual’s decision to binge drink has a statistically significant negative effect on his/her earnings. Furthermore, we conducted simulations of the short-run and long-run impacts of increasing the alcohol price. They showed that the tendency for an individual to binge drink heavily is reduced significantly, and the reduction is greater in the long-run than short-run simulation. Also, an individual's annual earnings were increased. However, in the structural model, an individual’s earnings have no significant effect on his/her tendency to engage in binge drinking. Our results contradict earlier findings from cross-section evidence that showed increased alcohol consumption raised an individual’s earnings or wages.