Does a rolling floor reduce the physical work demands and workload, and increase the productivity of truck drivers handling packed goods?

A PCM rolling floor (RF) was developed to reduce the risk of musculoskeletal complaints among truck drivers. The RF can be used to move packed goods automatically in and out of the cargo space. The efficacy of this intervention on physical work demands, energetic and perceived workload and productivity was evaluated by comparing nine truck drivers working with a RF and a traditional, non-moving floor during a working day. Since the RF was not used during the loading process, no effects were found. The RF reduced the unloading process by 8 min, decreased the frequency of lifting and setting down goods by 24%, decreased the frequency of handling goods below knee level by 79%, and decreased the frequency of entering the cargo space by 45%. No effect was found on the energetic and perceived workload. The RF resulted in a small increase in productivity.     

When is the discretization of a spatially distributed system good enough for control?

This paper describes a new and straightforward method for controlling spatially distributed plants based on low-order models obtained from spatial discretization techniques. A suitable level of discretization is determined by computing the sequence of ν-gaps between weighted models of successively finer spatial resolution, and bounding this by another sequence with an analytic series. It is proved that such a series forms an upper bound on the ν-gap between a weighted model in the initial sequence and the spatially distributed weighted plant. This enables the synthesis, on low-order models, of robust controllers that are guaranteed to stabilize the actual plant, a feature not shared by most model reduction methods where the gap between the high-order model and plant is often not known, and where the gap between high-order and reduced models may be too expensive to compute. Since the calculation of the current bound is based on weighted models of small state-dimension, the new method avoids the numerical problems inherent in large-scale model reduction based approaches. The ideas presented in this paper are demonstrated on a disturbance rejection problem for a 1D heat equation.     

Investigating the validity of subjective workload rating (NASA TLX) and subjective situation awareness rating (SART) for cognitively complex human–machine work

Subjective workload and situation awareness measures, such as the NASA task load index (TLX) and the situational awareness rating technique (SART), are frequently used in human–system evaluation. However, the interpretation of these ratings is debated. In this study, empirical evidence for the measures' theoretical assumptions was investigated by comparing operators' ratings collected immediately after performing a scenario and ratings collected after operators' acquisition through a video review of the scenario, knowledge of actual system states. Eighteen licensed control room operators participated in the simulator study, running 12 relatively challenging scenarios. It was found that the interpretation of TLX items involving introspection remained stable after operators acquired factual scenario knowledge, while the interpretation of items involving the perception of external events, such as situation awareness and performance, depended on the operators' scenario knowledge. The result shows that operators’ ratings could discriminate between mental effort, performance, frustration, and situation awareness. No clear evidence for the SART index as a measure of situation awareness was found. Instead, a subjective situation awareness measure developed for this study was distinct from workload and related to operator performance, showing that this type of measure warrants future investigation of its validity. The study findings help in developing measurement procedures and interpreting subjective measures. Finally, the study reveals that informing operators about the scenario can provide useful subjective ratings of situation awareness and performance. Future research should include procedures for how to inform participants adequately and efficiently in subjective assessments.     

What is the evidence for less shift work tolerance in older workers?

This paper explores the suggestion that older people would be less tolerant to shift work. Field studies on age-shift work interaction effects on sleep, fatigue, performance, accidents and health were reviewed. Studies on age-shift (morning, afternoon, night) and age-shift system (roster) interactions were also reviewed. In nine studies, shift and day workers were compared and interactions with age were addressed. Two studies reported more problems in older people, four studies reported opposite results, while in five studies no significant age-shift work interaction was observed. From across-shift comparisons (six studies), it was deduced that older compared with younger workers have more sleep problems with night shifts, while the opposite is true for morning shifts. This review did find some differences between older and younger workers, but did not find evidence for the suggestion of more shift work problems in older workers. STATEMENT OF RELEVANCE: This systematic review reveals the limited evidence that exists concerning shift work tolerance in older workers, highlighting an area for future research. Some interactions between age and shift type and shift system have been found, however. In view of these, it is argued that age-specific aspects should be considered in shift work planning.     

Do we want to keep working in 12-h shifts? The follow-up of the work schedule change in a Portuguese industrial company

BackgroundIn Europe, atypical work schedules assume an increasing position, framed by the so-called “adaptability regime”. Despite being seen as a “temporary” option, this regime supports the extension of the working hours up to 12 h per shift.ObjectiveThe purpose of this study was to analyse how the workers from a Portuguese industrial company perceive the impacts of a 12-h schedule, after replacing the former 8-h shift schedule.MethodsThe sample included a total of 87 shiftworkers of an industrial company. A mixed method research was followed based on the ergonomic work analysis, using observations; a self-report instrument describing a week working on 2 × 12 h; and a questionnaire.ResultsField study findings are consistent in showing that, in 2 × 12 h, the workers perceive the risks as resized, both physical risk factors (e.g., noise) and factors related to the work organization (e.g., work pace). The results also reveal a perceived aggravation of the main health outcomes: “sleep debt”, feeling of chronic fatigue, and muscles pains. Despite this, most workers prefer the new 12-h schedule, but not until their retirement age.ConclusionAt present, it is noticed that the new schedule receives collective acceptance and is considered the least-worst option; the advantages outside work seem to compensate the higher costs imposed by this schedule.Relevance to industryOur findings highlight ergonomics' contribution to the sustainability of the work in 12-h shifts, establishing the conditions that enable a technical-scientific opinion supporting the company's decision on the exposure length of the workers to these work schedules.     

When is it reasonable to implement the discontinuous sliding‐mode controllers instead of the continuous ones? Frequency domain criteria

Professor Utkin proposed an example showing that the amplitude of chattering caused by the presence of parasitic dynamics (stable actuators) in some systems governed by the First‐Order Sliding‐Mode Controller is lower than that produced by the Super‐Twisting Algorithm. This example served to motivate this paper reconsidering the problem of comparison of chattering in systems with stable actuators, and driven by Discontinuous Sliding‐Mode Controllers (DSMCs) and Continuous Sliding‐Mode Controllers (CSMCs). Comparison of chattering produced by DSMC and CSMC taking into account their amplitudes, frequencies, and average power (AP) needed to maintain the system into real‐sliding modes, allowing to conclude the following: (i) for systems with slow actuators, the amplitude of oscillations and AP produced by DSMC be smaller than those caused by CSMC; (ii) for bounded disturbances with fixed Lipschitz constant, there exist sufficiently fast actuators for which the amplitude of oscillations and AP produced by CSMC be smaller than those caused by DSMC.     

“… or is the question of being at once the most basic and the most concrete?” On the ambitions and responsibilities of contemporary American philosophy

At its centennial in 2001, the American Philosophical Association bravely proclaimed: “Philosophy Matters.” But does it? It won’t unless it reaches the concreteness of everyday life. To do so was Martin Heidegger’s ambition, and one can read Saul Kripke’s books as an attempt to get mainstream American philosophy beyond its abstractions. At length, Kripke’s efforts, on one reading, failed while Heidegger’s remained incomplete. A theory of commodification can get us closer to the things that matter to us in everyday life.     

On the dynamics of judgment: does the butterfly effect take place in human working memory?

Why do people hesitate—to do something, or not to do something—even when the data available to them remain constant? The neural model of human working memory (WM) we present in this paper explains hesitation as an emergent property of a complex dynamic structure of stored/processed information. WM is considered as a geometric space inhabited by a “society” of memes, i.e., complex informational structures. A large population of identical memes can cause a feeling, judgment, or intention in an individual. The memes navigate all over WM and interact with one another in a way resembling genetic cross-over; hence, new memes are born at several places in WM. Since the birth of contradictory memes is possible, populations of memes contributing to contradictory feelings, judgments, and plans grow in WM and fight for domination. A computer simulation of the process showed that WM's state sometimes goes to a two-focal “strange” attractor. Hence, sudden mental shifts, as, say, from love to hate and back from hate to love, may be caused by minute fluctuations in the densities of meme streams entering WM. The complex system theory calls this phenomenon the “butterfly effect”. We argue that this effect takes place in the human mind and also can take place in an advanced robot.     

Does peer assessment in on-line learning environments work? A systematic review of the literature

There is an increase use of Peer Assessment (PA) approaches in On-line Learning Environments to support students and teachers on educational process. However, the community still lacks a comprehensive understanding of how Peer Assessment behaves within these educational environments, since there are no studies that make an analysis of the researches which has been conducted in this context, analysing the benefits and disadvantages of the use of Peer Assessment. Thus, the main goal of this work is to investigate and better understand how PA contributes in student learning as well as can bring benefits to the teachers involved. In order to meet our goal, we conducted a systematic literature review (SLR). In summary, the main findings are: (1) there are empirical evidences of the benefits of using PA in both industry and academy, and in several educational levels; (2) PA is most addressed to the correction of written activities on on-line courses; (3) About 60% of the articles showed PA improvement in student performance; (4) About 1/3 of the studies showed PA brings some benefits to teachers; (5) In some studies the use of the PA had difficulties, especially issues related to student motivation, which impairs the peer review process.     

Advancing digital libraries in Germany and creating distributed scientific resources – the telos working group at Darmstadt University of Technology

This text gives an overview of the work of the author and his working group telos over the past 20years and sketches the main focus of this work, i.e., creating technologies for distributed scientific resources and their intelligent retrieval.     

What is the Right R&D Strategy for Overcoming the Difficulties of the South Korean IT Industry?

This study proposes new strategies for the information technology (IT) industry in South Korea, provides objectives for the South Korean IT industry and articulates the roles of the Korean government agencies, companies and users. Specifically, it covers South Korean IT strategies employed during several periods, including a stagnant period and a more recent period reflecting new successful IT environments of developed countries. South Korean IT companies should recognize the importance of user interface and user experience technologies as a next key global IT industry trend. Raising this awareness is critical in increasing the global competitiveness of the Korean IT industry. Furthermore, South Korean government agencies should take more active role in constructing and improving interactive environments that would benefit both companies and users. For future research, it is imperative to investigate the specific roles of companies, users and government agencies with respect to IT usage.     

How many cores do we need to run a parallel workload: A test drive of the Intel SCC platform?

As semiconductor manufacturing technology continues to improve, it is possible to integrate more and more transistors onto a single processor. Many-core processor design has resulted in part from the search to utilize this enormous transistor real estate. The Single-Chip Cloud Computer (SCC) is an experimental many-core processor created by Intel Labs. In this paper we present a study in which we analyze this innovative many-core system by running several workloads with distinctive parallelism characteristics. We investigate the effect on system performance by monitoring specific hardware performance counters. Then, we experiment on varying different hardware configuration parameters such as number of cores, clock frequency and voltage levels. We execute the chosen workloads and collect the timing, power consumption and energy consumption information on such a many-core research platform. Thus, we can comprehensively analyze the behavior and scalability of the Intel SCC system with the introduced workload in terms of performance and energy consumption. Our results show that the profiled parallel workload execution has a communication bottleneck on the Intel SCC system. Moreover, our results indicate that we should carefully choose the number of cores to execute different workloads in order to yield a balance between execution performance and energy efficiency for different applications.     

Who is sleepier on the night shift? The influence of bio-psycho-social factors on subjective sleepiness of female nurses during the night shift

Sleepiness is a common complaint during the night shift and may impair performance. The current study aims to identify bio-psycho-social factors associated with subjective sleepiness during the night shift. Ninety-two female nurses working rotating shifts completed a sociodemographic questionnaire, the Munich ChronoType Questionaire for shift workers, the Pittsburg Sleep Quality Index, and the Pre-sleep Arousal Scale. Subjective sleepiness was measured hourly during two night shifts using the Karolinska Sleepiness Scale, and activity monitors assessed sleep duration 24-h before each shift. Findings showed that increased sleepiness was associated with increased age in nurses with early chronotypes and with more children. High cognitive pre-sleep arousal, but not sleep, was associated with increased sleepiness, especially in late chronotypes. The impact of bio-psycho-social factors on night shift sleepiness is complex, and depends on mutual interactions between these factors. Nurses most prone to increased sleepiness must develop personal strategies for maintaining vigilance on the night shift.

Practitioner Summary: This study aims to identify bio-psycho-social factors associated with subjective sleepiness of female nurses during the night shift. Increasing sleepiness was associated with increased age in nurses with early chronotypes and with more children. Increased cognitive pre-sleep arousal, but not sleep, was associated with increased sleepiness, especially in late chronotypes.     

To Facebook or to Face Book? An investigation of how academic performance of different personalities is affected through the intervention of Facebook usage

This paper investigates how students’ personality types influence their academic performance and how Facebook usage intervenes these associations. A survey questionnaire method was adopted to collect data from students in five public universities in Malaysia. An analysis of 1165 questionnaires shows that all five dimensions of personality from big five model predict academic performance. In addition, shyness also predicted academic performance positively while a negative relationship was found between loneliness and students’ academic performance. The mediating role of Facebook usage was established only in the relationships of academic performance with extraversion, agreeableness and loneliness. A discussion of these findings, limitations of the study and future research directions are provided.     

Mapping urban areas on a global scale: which of the eight maps now available is more accurate?

Eight groups from government and academia have created 10 global maps that offer a ca 2000 portrait of land in urban use. Our initial investigation found that their estimates of the total amount of urban land differ by as much as an order of magnitude (0.27–3.52 ×10⁶ km²). Since it is not possible for these heterogeneous maps to all represent urban areas accurately, we undertake the first global accuracy assessment of these maps using a two-tiered approach that draws on a stratified random sample of 10 000 high-resolution Google Earth validation sites and 140 medium-resolution Landsat-based city maps. Employing a wide range of accuracy measures at different spatial scales, we conclude that the new MODIS 500 m resolution global urban map has the highest accuracy, followed by a thresholded version of the Global Impervious Surface Area map based on the Night-time Lights and LandScan datasets.