Objective: The focal length of available optical see-through (OST) head-mounted displays (HMDs) is at least 2 m; therefore, during manual tasks, the user eye cannot keep in focus both the virtual and ...real content at the same time. Another perceptual limitation is related to the vergence-accommodation conflict, the latter being present in binocular vision only. This paper investigates the effect of incorrect focus cues on the user performance, visual comfort, and workload during the execution of augmented reality (AR)-guided manual task with one of the most advanced OST HMD, the Microsoft HoloLens. Methods: An experimental study was designed to investigate the performance of 20 subjects in a connect-the-dots task, with and without the use of AR. The following tests were planned: AR-guided monocular and binocular, and naked-eye monocular and binocular. Each trial was analyzed to evaluate the accuracy in connecting dots. NASA Task Load Index and Likert questionnaires were used to assess the workload and the visual comfort. Results: No statistically significant differences were found in the workload, and in the perceived comfort between the AR-guided binocular and monocular test. User performances were significantly better during the naked eye tests. No statistically significant differences in performances were found in the monocular and binocular tests. The maximum error in AR tests was 5.9 mm. Conclusion: Even if there is a growing interest in using commercial OST HMD, for guiding high-precision manual tasks, attention should be paid to the limitations of the available technology not designed for the peripersonal space.
•The optimal band selection is applied to design a network module.•A method is proposed for evaluating and optimizing the convolutional kernel.•The optimal kernels and features show semantics and ...make the network robust.•The impulsiveness or cyclostationarity can be used as semantics.•An improvement of 4% and 3% is achieved under two scenarios, respectively.
Deep data-driven methods for fault diagnosis, as an engineering-oriented approach, rely heavily on target data. For engineering applications, the working conditions of rotating machinery fluctuate from time to time and a collection for any working conditions is impossible. To tackle this problem, a robust network with optimal kernels named EnvelopeNet is proposed for extracting solid information and eliminating the influence of fluctuations. In the EnvelopeNet, a feature evaluation building block named envelope module is constructed based on optimal band selection theory to optimize the kernels. Compared with the kurtogram, the learned optimal kernels and features show strong semantics which helps the network become robust. The EnvelopeNet is validated under the approximate speed and mixed speed scenarios. The results show that the EnvelopeNet could provide admirable generalization ability for fluctuating working conditions and an average improvement of about 4% and 3% over existing approaches under two scenarios respectively.
This study examines the role of negative work rumination and recovery experiences in explaining the association between workplace incivility and employee insomnia symptoms. Drawing on the ...perseverative cognition model of stress and the effort-recovery model, we hypothesize a moderated mediation model in which workplace incivility is associated with insomnia symptoms via negative work rumination. This indirect effect is proposed to be conditional on employees' reported level of recovery experiences (i.e., psychological detachment from work and relaxation during nonwork time). In examining this model, we further establish a link between workplace incivility and sleep and identify one pathway to explain this relationship, as well as resources that may be used to halt the negative spillover of workplace incivility on sleep. Based on a sample of 699 U.S. Forest Service employees, we find support for a moderated mediation model in which the association between workplace incivility and increased insomnia symptoms via increased negative work rumination was weakest for employees reporting high levels of recovery experiences during nonwork time. Findings from the current study contribute to our understanding of why workplace incivility is associated with nonwork outcomes, as well as point to implications for interventions aimed at promoting employees' recovery from work.
Two complementary studies were conducted to compare emotional support and instrumental support in the workplace. Study 1 included meta-analyses with 142 independent samples containing 68,354 ...participants and tested the moderation effects of source of support (supervisor vs. coworker) and support scale type (received vs. availability). Study 2 incorporated a two-wave survey design and objective ratings of participant job demands. Overall, emotional support and instrumental support were strongly correlated and demonstrated a similar pattern of effects with work criteria. However, the emotional support-instrumental support relationship is stronger within occupations higher in emotional labor demands. Moderation effects of support on stressor-criteria relationships were also reviewed among the primary studies in the meta-analysis. For both emotional support and instrumental support, buffering effects and reverse buffering effects were commonly found, which indicates that contextual factors need to be considered to determine when support mitigates or exacerbates the effect of stressors on work criteria. Moderation effects of source of support (supervisor vs. coworker) and support scale type (received vs. availability) were also tested. In general, support was more strongly correlated with criteria when the source of support was the supervisor and the scale included items about the availability of support. The findings from the two studies provide researchers and practitioners a guide for when emotional support and instrumental support converge or diverge.
What is sustainable fashion? Henninger, Claudia E; Alevizou, Panayiota J; Oates, Caroline J
Journal of fashion marketing and management,
01/2016, Volume:
20, Issue:
4
Journal Article
Peer reviewed
Open access
Purpose
The purpose of this paper is to examine what the term sustainable fashion means from the perspective of micro-organisations, experts, and consumers.
Design/methodology/approach
This research ...is qualitative in nature, utilising a multi-methods case study approach (semi-structured interviews, semiotics, questionnaires). Grounded analysis was applied to analyse the data.
Findings
Findings indicate that interpretation of sustainable fashion is context and person dependent. A matrix of key criteria provides the opportunity to find common elements.
Research limitations/implications
Due to the nature of this research the sample size is limited and may not be generalised. Data were collected in the UK and are limited to a geographical region.
Practical implications
An important implication is that defining sustainable fashion is vital in order to avoid challenges, such as greenwashing, which were faced in other industries that have a longer history in sustainable practices. Micro-organisations should take advantage of identifying key sustainable fashion criteria, which will enable them to promote their fashion collections more effectively.
Social implications
The criteria identified provide assurance for consumers that sustainable fashion is produced with social aspects in mind (fair wages, good working conditions).
Originality/value
The paper proposes a matrix that allows micro-organisations to clearly identify their collections as sustainable.
The performance of fixed ejector is limited by working conditions, so it is difficult to meet the operating requirements of electric vehicle heat pump system under varying conditions and wide ...temperature range. In this paper, a transcritical CO2 refrigeration cycle with dual ejectors in parallel (DEP) for electric vehicle heat pump system is established and its operation condition weight statistics method in all climate is proposed. On this basis, a fixed ejector optimization method based on the genetic algorithm is proposed, which takes the increment of integrated part load value (ΔIPLV) compared to the conventional transcritical CO2 refrigeration cycle (CON) system as the evaluation index. The performance analysis results show that under the cooling conditions, the coefficient of performance (COP) of DEP system with the optimized ejector for cooling is increased by 17.32%–23.42% compared to the CON system, and the COP of the transcritical CO2 refrigeration cycle with a single ejector (SEJ) system is increased by 7.31%–9.47%. In the heating mode, the COP of DEP system with the optimized ejector for heating is increased by 18%–19.79%, while the COP of SEJ system with the unoptimized ejector is decreased by 0.07%–2.43%.
•An electric vehicle CO2 heat pump system with dual ejectors in parallel is investigated.•The system operation condition weight statistics method in all climate is proposed.•A fixed ejector optimization method based on the genetic algorithm is proposed.•The performance of the system with optimized ejector is effectively improved.
The future of work and health The Lancet
The Lancet (British edition),
10/2023, Volume:
402, Issue:
10410
Journal Article
Peer reviewed
Open access
The first paper in the Series aims to correct this situation and identifies six emerging challenges, including the influence of technology on the nature of work and the looming threat of the effect ...of climate change on work. An umbrella review undertaken in the second paper of the Series explores work-related causes of mental health conditions and has some striking findings. Marjorie Kelly describes a new “manifest destiny” in her book Wealth Supremacy: How the Extractive Economy and the Biased Rules of Capitalism Drive Today's Crises, in which a decades-long war against workers has been waged, defined by the destruction of unions, the transfer of 40% of all workers in the USA to a contingent workforce with precarious and less healthy conditions, and culminating in the disappearance of jobs altogether through automation.
The development of synthetic methods for micro/nano materials with precisely controlled structures, morphologies, and local compositions is of great importance for the advancement of modern ...nanotechnology. The electrospray method is a "platform" approach for the preparation of a broad range of micro-/nanostructures; electrospray is simple and scalable. This review summarizes recent research on the micro-/nanostructures prepared via the electrospray route. These include spherical structures (e.g. simple, porous, Janus, and core-shell particles), non-spherical structures (e.g. red blood cell-like and spindle-like particles, multi-compartment microrods, 2D holey nanosheets, and nanopyramids), and assembled structures. The experimental details, underlying physical/chemical principles, and key benefits of these structures are comprehensively discussed. The effects and importance of nozzle design, properties of feeding solutions (e.g. concentration of solute, polymer additives, solvent/nonsolvent combinations), working environment (e.g. temperature and humidity), and types of collection media are highlighted.
The purpose of this study is to provide industry practitioners with a better understanding of the impacts of high-temperature conditions on construction labor productivity. Such information could ...assist in the establishment of plans to prevent heat-stress injuries and help improve the safety and comfort of construction labor working environments. On-site WBGT (Wet Bulb Globe Temperature) data and labor productivity data related to direct work time, indirect work time and idle time were measured for two construction projects involving 16 rebar workers in the summer of 2014 in Beijing, China. The period from 14:00 to 15:00 was identified as the most hazardous for workers throughout the day, and the period from 07:00 to 09:00 was identified as the least hazardous time. Productivity models were further used to analyze the collected data. The model results demonstrated that high-temperature environments decrease labor productivity, with the percentage of direct work time decreasing by 0.57% and the percentage of idle time increasing by 0.74% when the WBGT increased by 1 °C. Moreover, the percentage of direct work time increased by 0.33% when the workers' experience increased by 1 year and decreased by 0.72% when the workers' age increased by 1 year. Overall, the results demonstrated that high-temperature environments impose heat stress on the human body and decreases labor productivity in the construction industry.
•Impact of high-temperature on construction labor productivity was evaluated.•On-site WBGT and labor productivity data in two projects were collected.•14:00 to 15:00 time period was the most hazardous time for the laborers.•Direct work time decreased by 0.57% when WBGT increased by 1 °C.•Idle time increased by 0.74% when WBGT increased by 1 °C.
Disclosing ‘masked employees’ in Europe Millán, Ana; Millán, José María; Caçador-Rodrigues, Leonel
Small business economics,
08/2020, Volume:
55, Issue:
2
Journal Article
Peer reviewed
Open access
In this study, we examine whether job control, job demands and job outcomes of ‘dependent self-employed workers’, i.e. the workers in this particular grey zone between employment and self-employment, ...are more similar to those of the self-employed or paid employed. To this end, we use microdata drawn from the 2010 wave of the European Working Conditions Survey for 34 European countries. First, we develop and validate a psychometrically sound multidimensional scale for these 3 key constructs by conducting both exploratory and confirmatory factor analysis. Then, multilevel (hierarchical) linear regressions are used to test the validity of our hypotheses. Our results suggest that these hybrid work relationships are endowed with the least favourable attributes of both groups: lower job control than self-employed workers, higher job demands than paid employees and, overall, worse job outcomes than both.
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