| 1. |
- Arvidsson, Inger, et al.
(författare)
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Changes in physical workload with implementation of mouse-based information technology in air traffic control
- 2006
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 36:7, s. 613-622
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Tidskriftsartikel (refereegranskat)abstract
- Effects on physical workload were quantified when introducing new information technology in air traffic control. Seven female and 7 male air traffic controllers were studied in an old control system, and during simulated-but similar-work in a new, mouse-based system. Postures, movements and muscular load were recorded (inclinometry for head, neck, back and upper arms; goniometry for wrists; elect romyography for the trapezius and forearm extensor muscles). The new system was associated with lower movement velocities than the old one (examples: [50th percentiles] head flexion: 2 vs. 5 degrees/s, P < 0.01; right arm elevation: 3 vs. 6 degrees/s; P < 0.01; [90th percentile] wrist flexion: 19 vs. 50 degrees/s, P < 0.01), less varying postures (head: 95th-5th percentile range 17 degrees vs. 34 degrees; P < 0.01), and less muscular rest in the right forearm extensors (3.5% vs. 9% of time; P < 0.05). The old/new system differences were amplified at high work intensities. The new air traffic control system caused a major change of physical exposures, probably associated with an increased risk of musculoskeletal disorders in arms and hands. Relevance to industry While this study concerned the specific changes in the introduction of a new air traffic control system, we believe that the findings are applicable to similar technological developments in other settings. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Arvidsson, Inger, et al.
(författare)
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Neck postures in air traffic controllers with and without neck/shoulder disorders.
- 2008
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Ingår i: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 39:2, s. 255-260
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Tidskriftsartikel (refereegranskat)abstract
- Prolonged computer work with an extended neck is commonly believed to be associated with an increased risk of neck–shoulder disorders. The aim of this study was to compare neck postures during computer work between female cases with neck–shoulder disorders, and healthy referents. Based on physical examinations, 13 cases and 11 referents were selected among 70 female air traffic controllers with the same computer-based work tasks and identical workstations. Postures and movements were measured by inclinometers, placed on the forehead and upper back (C7/Th1) during authentic air traffic control. A recently developed method was applied to assess flexion/extension in the neck, calculated as the difference between head and upper back flexion/extension. Results: cases and referents did not differ significantly in neck posture (median neck flexion/extension: −10° vs. −9°; p=0.9). Hence, the belief that neck extension posture is associated with neck–shoulder disorders in computer work is not supported by the present data.
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| 3. |
- Bergkvist, Bo, et al.
(författare)
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Pools and fluxes of carbon in three Norway spruce ecosystems along a climatic gradient in Sweden
- 2008
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Ingår i: Biogeochemistry. - : Springer Science and Business Media LLC. - 0168-2563 .- 1573-515X. ; 89:1, s. 7-25
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents an integrated analysis of organic carbon (C) pools in soils and vegetation, within-ecosystem fluxes and net ecosystem exchange (NEE) in three 40-year old Norway spruce stands along a north-south climatic gradient in Sweden, measured 2001-2004. A process-orientated ecosystem model (CoupModel), previously parameterised on a regional dataset, was used for the analysis. Pools of soil organic carbon (SOC) and tree growth rates were highest at the southernmost site (1.6 and 2.0-fold, respectively). Tree litter production (litterfall and root litter) was also highest in the south, with about half coming from fine roots (< 1 mm) at all sites. However, when the litter input from the forest floor vegetation was included, the difference in total litter input rate between the sites almost disappeared (190-233 g C m(-2) year(-1)). We propose that a higher N deposition and N availability in the south result in a slower turnover of soil organic matter than in the north. This effect seems to overshadow the effect of temperature. At the southern site, 19% of the total litter input to the O horizon was leached to the mineral soil as dissolved organic carbon, while at the two northern sites the corresponding figure was approx. 9%. The CoupModel accurately described general C cycling behaviour in these ecosystems, reproducing the differences between north and south. The simulated changes in SOC pools during the measurement period were small, ranging from -8 g C m(-2) year(-1) in the north to +9 g C m(-2) year(-1) in the south. In contrast, NEE and tree growth measurements at the northernmost site suggest that the soil lost about 90 g C m(-2) year(-1).
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| 4. |
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| 5. |
- Dahlgren, Anders, et al.
(författare)
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Planning Rescue Services with Non-Stationary Rescue Units
- 2009
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Ingår i: Fire Technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 45:3, s. 239-255
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Tidskriftsartikel (refereegranskat)abstract
- Geographical accessibility is fundamental when planning rescue services. At present there are several programs for computing the accessibility of stationary rescue units. This study suggests a method for evaluating geographic accessibility in scenarios containing also non-stationary units. The method supports the planning process by matching the risk of an incident occurring with the rescue units’ capabilities and accessibility. The method is implemented in the computer program Rescue Unit Planner. The result of the analysis is presented in thematic maps and graphs as level of coverage, mean response time and concentration. The method and the computer program have been evaluated in two case studies: one urban area in southern Sweden and one rural area in northern Sweden. The case studies show that that this method can be useful in the rescue service planning process.
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| 6. |
- Dominic, Chris
(författare)
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Integrating Packaging Suppliers into the Supply/Demand Chain
- 2005
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Ingår i: Packaging Technology and Science. - : Wiley. - 0894-3214 .- 1099-1522. ; 18, s. 151-160
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the results from qualitative studies done on leading edge companies in Supply/Demand Chain Management in Sweden. The aim of the study is to create a knowledge base, identify the Network Integrators, and with reference to previous studies conducted in the packaging industry, analyse the development for packaging suppliers.
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| 7. |
- Hansson, Gert-Åke, et al.
(författare)
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Precision of measurements of physical workload during standardised manual handling. Part II: Inclinometry of head, upper back, neck and upper arms
- 2006
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Ingår i: Journal of Electromyography & Kinesiology. - : Elsevier BV. - 1050-6411 .- 1873-5711. ; 16:2, s. 125-136
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Tidskriftsartikel (refereegranskat)abstract
- For measuring the physical exposure/workload in studies of work-related musculoskeletal disorders, direct measurements are valuable. However, the between-days and between-subjects variability, as well as the precision of the method per se, are not well known. In a laboratory, six women performed three standardised assembly tasks, all of them repeated on three different days. Triaxial inclinometers were applied to the head, upper back and upper arms. Between-days (within subjects) and between-subjects (within tasks) variance components were derived for the 10th, 50th and 90th percentiles of the angular and the angular velocity distributions, and for the proportion of time spent in predefined angular sectors. For percentiles of the angular distributions, the average between-days variability was 3.4 degrees , and the between-subjects variability 4.0 degrees . For proportion of time spent in angular sectors, the variability depended on the percentage of time spent in the sector; the relative variability was scattered and large, on average 103% between days and 56% between subjects. For the angular velocity percentiles, the average between-days variability was 7.9%, and the average between-subjects variability was 22%. The contribution of the measurement procedure per se to the between-days variability, i.e., the imprecision of the method, was small: less than 2 degrees for angles and 3% for angular velocity.
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| 8. |
- Jonsson, Oskar, et al.
(författare)
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CONSUMER PERCEPTIONS AND PREFERENCES ON SOLID WOOD, WOOD-BASED PANELS, AND COMPOSITES : A REPERTORY GRID STUDY
- 2008
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Ingår i: Wood and Fiber Science. - 0735-6161. ; 40:4, s. 663-678
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge about consumer perception and preferences on solid wood, wood-based panels, and wood-based composites is important for product development and marketing. The aim of this study was to identify attributes and associations that people use to describe different types of wood materials and to explore how they relate to preferences. The study involved nine samples that were evaluated with the Kelly's repertory grid technique and content analysis. Based on respondents' answers. 19 core categories reflecting sample attributes were extracted. General preferences for each sample were also recorded. Principal component analysis generated two factors describing 1) naturalness, wood-likeness, softness, unprocessed origin, living, pleasant, and high value; and 2) solid and homogeneous impression. A third, preliminary factor included categories describing irregular pattern,sleekness, and smoothness. The wood samples were most liked, whereas composites and panels were not appreciated. Preferred core categories were naturalness, wood-likeness, smoothness, living impression, and value. The least liked core categories were processed, hard, and high weigh. The implications of the results for product development and marketing are discussed.
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| 9. |
- Kazmierczak, Karolina, et al.
(författare)
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An integrated analysis of ergonomics and time consumption in Swedish 'craft-type' car disassembly.
- 2005
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Ingår i: Applied Ergonomics. - : Elsevier BV. - 0003-6870 .- 1872-9126. ; 36:3, s. 263-73
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Tidskriftsartikel (refereegranskat)abstract
- Car disassembly is at the edge of extensive rationalisations due to increased legislative demands for recycling. This study focused on (1) assessing current mechanical exposures (physical work loads) for comparison with future rationalised systems, with particular emphasis on time aspects, (2) analysing disassembly work in terms of time consumption and exposures in constituent tasks as defined by a loss analysis technique, and (3) predicting the consequences of car disassembly rationalisation for mechanical exposures. The study showed that disassembly implied pronounced circulatory loads, and that more walking and higher lumbar peak loads were found than in studies of assembly work. Value-adding tasks comprised 30% of the total working time, and implied higher postural exposures for the head, arm, trunk and wrist, as well as less opportunities to recover, as compared to non-value-adding tasks. Organisational-type rationalisations can be expected to increase the time spent in value-adding work, thus increasing local exposures for the average worker, while a concurrent increase in mechanisation level might reduce circulatory exposures, the amount of walking, and peak lumbar loads.
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| 10. |
- Kazmierczak, Karolina, et al.
(författare)
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Observer reliability of industrial activity analysis based on video recordings
- 2006
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 36:3, s. 275-282
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to assess the agreement between observers analyzing activity patterns during truck engine assembly work based on video recordings. Two observers observed the recordings of nine workers, on the average 2.2 h long, assigning activities to four activity categories. For each activity category data were obtained on the mean duration of uninterrupted sequences of activities and their relative time proportion in the job. This data was analyzed with 2-way crossed ANOVA algorithms to derive the components of variance attributed to disagreement between observers, to differences between filmed subjects, and to residual "unexplained" variance. The latter was interpreted as an estimate of within-observer variability and possible interactions between subject and observer. While the observers disagreed about the overall time proportions for the four activity categories by no more than 3.7% of time, their second-to-second classification disagreed for 13% of the total analysis time. The between-observer variance was small as compared to within-observer variance and the variance between Subjects performing the same job. Simulations based oil the variance components showed that a group mean of the proportion of direct work could be determined with a standard deviation within 5% of the mean by having two observers analyzing one 2-h video recording once, each. Relevance to industry The results of this study may support decision making when designing a reliable video-based analysis of industrial work. Thus, the study helps production engineers, ergonomics practitioners and researchers allocate resources between data collection and data analysis, based on their preferences for precision and power of a particular study. (c) 2006 Elsevier B.V. All rights reserved.
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