Everyday work investigations for safety

A key theme in safety is the investigation and improvement of work processes and conditions. This is built on a tradition of studying accidents, but there is growing interest in the investigation of everyday work. Researchers have started using terms such as success, normal and everyday work investigations, but behind these can be different activities. This paper makes explicit some considerations behind investigations of everyday work, how these considerations shape an investigation, and how they reflect different schools of thought. These considerations can be used as an aid for designing everyday work investigations for safety and serve as a first step towards critical reflection on investigating everyday work.     

Automated gaze-based mind wandering detection during computerized learning in classrooms

We investigate the use of commercial off-the-shelf (COTS) eye-trackers to automatically detect mind wandering—a phenomenon involving a shift in attention from task-related to task-unrelated thoughts—during computerized learning. Study 1 (N?=?135 high-school students) tested the feasibility of COTS eye tracking while students learn biology with an intelligent tutoring system called GuruTutor in their classroom. We could successfully track eye gaze in 75% (both eyes tracked) and 95% (one eye tracked) of the cases for 85% of the sessions where gaze was successfully recorded. In Study 2, we used this data to build automated student-independent detectors of mind wandering, obtaining accuracies (mind wandering F₁?=?0.59) substantially better than chance (F₁?=?0.24). Study 3 investigated context-generalizability of mind wandering detectors, finding that models trained on data collected in a controlled laboratory more successfully generalized to the classroom than the reverse. Study 4 investigated gaze- and video- based mind wandering detection, finding that gaze-based detection was superior and multimodal detection yielded an improvement in limited circumstances. We tested live mind wandering detection on a new sample of 39 students in Study 5 and found that detection accuracy (mind wandering F₁?=?0.40) was considerably above chance (F1?=?0.24), albeit lower than offline detection accuracy from Study 1 (F₁?=?0.59), a finding attributable to handling of missing data. We discuss our next steps towards developing gaze-based attention-aware learning technologies to increase engagement and learning by combating mind wandering in classroom contexts.

     

Text complexity of open educational resources in Portuguese: mixing written and spoken registers in a multi-task approach

Language Resources and Evaluation - This paper presents a study on text complexity of Open Educational Resources (OER) in Brazilian Portuguese. In a data analysis of the Brazilian Ministry of...     

Quantification of denitrification potential in carbonaceous trickling filters

Biofilm samples from a carbonaceous trickling filter (TF) were evaluated in bench scale reactors to determine their maximum potential denitrification rates. Intact, undisturbed biofilms were placed into 0.6 L bench-scale reactors filled with sterilized, primary clarifier effluent spiked with nitrate to a final concentration of 16-18 mg/L as N. Dissolved oxygen concentrations were maintained between 2 and 4 mg/L in the bulk aqueous phase. Nitrate loss from the reactors was monitored over a 5h period. Denitrification rates of 3.09-5.55 g-N/m(2)day were observed with no initial lag period. This suggests that the capacity for denitrification is inherent in the biofilm and that denitrification can take place even when oxygen is present in the bulk aqueous phase. There were no significant differences in denitrification rates per unit area of media (g-N/m(2)day) either between (a). experimental runs or (b). sampling locations over the trickling filter. This suggests that denitrification potentials are uniform over the entire volume of the full-scale TF. For wastewater treatment plants with TFs that currently nitrify downstream, this approach may be used to meet less stringent permitted discharge concentrations and may allow some facilities to postpone or eliminate construction of additional unit processes for denitrification.     

NIR luminescent Er/Yb co-doped SiO2–ZrO2 nanostructured planar and channel waveguides: Optical and structural properties

Optical and structural properties of planar and channel waveguides based on sol–gel Er³⁺ and Yb³⁺ co-doped SiO₂–ZrO₂ are reported. Microstructured channels with high homogeneous surface profile were written onto the surface of multilayered densified films deposited on SiO₂/Si substrates by a femtosecond laser etching technique. The densification of the planar waveguides was evaluated from changes in the refractive index and thickness, with full densification being achieved at 900 °C after annealing from 23 up to 500 min, depending on the ZrO₂ content. Crystal nucleation and growth took place together with densification, thereby producing transparent glass ceramic planar waveguides containing rare earth-doped ZrO₂ nanocrystals dispersed in a silica-based glassy host. Low roughness and crack-free surface as well as high confinement coefficient were achieved for all the compositions. Enhanced NIR luminescence of the Er³⁺ ions was observed for the Yb³⁺-codoped planar waveguides, denoting an efficient energy transfer from the Yb³⁺ to the Er³⁺ ion.     

全尺寸深井钻井模拟装置对钻井技术发展的影响

缩短钻井周期是降低深井钻井成本和钻井风险的关键,这需要钻井新技术、新工艺、新材料、新工具的研究与应用,这必然要很大程度上依赖于大量的室内试验。斯伦贝谢Terra Tek钻完井实验室有全球最先进的全尺寸钻井模拟试验装置,在30多年间做了大量的模拟试验,试验结果对钻井技术发展、钻头设计、钻井液体系优选及性能优化起到了积极的促进作用。在介绍Terra Tek全尺寸钻井模拟试验装置的组成及主要功能的基础上,分析了该实验室在美国岩石力学协会钻井论坛、冲击钻井及深井钻井模拟试验中取得的主要成果,并介绍了该实验室在页岩气地层特点、开发技术和井眼稳定等方面取得的研究进展。      

Situation awareness: some conditions of possibility

Situation awareness (SA) has become a ubiquitous object of knowledge in our discourses of human performance and accident explanation. Based on Michel Foucault's archaeological approach, in this paper, we examine SA by mapping the ‘conditions of possibility’ for this object to emerge. By highlighting the logic that SA builds upon, the political need that it intends to address, and the knowledges that delimitate it in its constitution, we aim to display the contingent nature of this object. Ultimately, we argue that as a discursive object, SA has effects.     

The psychology of accident investigation: epistemological,preventive, moral and existential meaning-making

This paper extends research on accident investigation as exercises in political sensemaking, by considering the possible psychological meaning-making purposes of accident investigation. Accident investigations and reports serve epistemological or preventive aims: finding out what went wrong and avoiding recurrence. These are not necessarily the same: the variables that explain a particular event might diverge from those that help forestall a larger family of events. In addition, accident investigation serves moral and existential purposes. Accident investigations are (often implicitly) expected to render people's suffering accountable to reason and open to solution, prevention and elimination. The Western world tends to locate both the meaning and cause of suffering in the realm of human moral choice, which typically condenses accounts of failure down to single acts and actors. This competes with increasingly complex epistemological narratives of accidents that have neither obvious causes nor clear, linear cause–effect relationships.