Can accelerometry accurately predict the energy cost of uphill/downhill walking?

To evaluate whether an activity monitor based on body acceleration measurement can accurately assess the energy cost of the human locomotion, 12 subjects walked a combination of three diVerent speeds (preferred speed±1 km/h) and seven slopes (-15 to + 15% by steps of 5%) on a treadmill. Body accelerations were recorded using a triaxial accelerometer attached to the low back. The mean of the integral of the vector magnitude (norm) of the accelerations (mIAN) was calculated. [Vdot]O₂ was measured using continuous indirect calorimetry. When the results were separately analysed for each incline, mIAN was correlated to [Vdot]O₂ (average r = 0.87, p < 0.001, n = 36). [Vdot]O₂ was not significantly correlated to mIAN when data were globally analysed (n = 252). Large relative errors occurred when predicted [Vdot]O₂ (estimated from data of level walking) was compared with measured [Vdot]O₂ for different inclines (-53% at + 15% incline, to + 55% at -15% incline). It is concluded that without an external measurement of the slope, the standard method of analysis of body accelerations cannot accurately predict the energy cost of uphill or downhill walking.     

Can accelerometry accurately predict the energy cost of uphill/downhill walking?

To evaluate whether an activity monitor based on body acceleration measurement can accurately assess the energy cost of the human locomotion, 12 subjects walked a combination of three different speeds (preferred speed +/- 1 km/h) and seven slopes (-15 to +15% by steps of 5%) on a treadmill. Body accelerations were recorded using a triaxial accelerometer attached to the low back. The mean of the integral of the vector magnitude (norm) of the accelerations (mIAN) was calculated. VO2 was measured using continuous indirect calorimetry. When the results were separately analysed for each incline, mIAN was correlated to VO2 (average r = 0.87, p<0.001, n = 36). VO2 was not significantly correlated to mIAN when data were globally analysed (n = 252). Large relative errors occurred when predicted VO2 (estimated from data of level walking) was compared with measured VO2 for different inclines (-53% at +15% incline, to +55% at -15% incline). It is concluded that without an external measurement of the slope, the standard method of analysis of body accelerations cannot accurately predict the energy cost of uphill or downhill walking.     

The Ergonomic Evaluation of Two Jobs in an Iron Foundry∗

Abstract

An ergonomic study was made in an iron foundry on the working conditions of a group of men assigned to moulding operations, using an old, manual method and a new method with a speed ‘ sandslinger ’. With both methods of moulding the workers were subject to vibrations.

The heart rate, the energy cost and the vertical vibrations during work were determined while using the old and new moulding methods.

The results obtained showed that the use of the ‘ sandslinger ’ considerably reduced the muscular work required for moulding operations and eliminated the severe vibrations (frequency 10 Hz, amplitude 2-5 mm) in the upper limbs, transmitted by the pneumatic rammer used in the old type of hand ramming.

During the operation of the ‘ sandslinger ’ (in the seated, position), two types of whole-body vibrations were found: one type with rather low frequency (3 HZ) and moderate amplitude (0·8—1 mm), and another type with a much higher frequency (25 Hz) and moderate amplitude (0·05 mm)

The human tolerance to the vibrations transmitted from the scat of the ‘ sandslinger ’ was estimated from the literature. Several possibilities of eliminating unpleasant vibrations were also considered.     

Microclimate in ski boots – Temperature,relative humidity,and water absorption

Ski boot quality is determined by mechanical properties and comfort. Comfort is strongly affected by cold feet. The purpose of this study was to determine the microclimate in ski boots. Climate chamber tests with five male subjects and field tests with two male subjects were conducted. Temperature and relative humidity were measured using four sensors placed on the foot and one on the liner. Absorbed water in liners and socks was measured with a precision balance. The subjects gave subjective ratings for comfort. The toe sensor temperature dropped below 20 °C at an ambient temperature of 0 °C, −10 °C, and −20 °C. Relative humidity values at the foot were as high as 78% in the climate chamber and 93% in the field. Water absorption in socks and liners ranged from 4 to 10 g in the climate chamber and 19 to 45.5 g in the field. The results reveal the importance of keeping the feet and in particular the toes warm during skiing. One possible improvement may be to construct the liner so that sweat and melted snow are kept as far away as possible from the foot. Liner material with high water absorption capacity and hydrophobic socks were suggested to prevent wet feet.     

The Applications of Wavelets in Hierarchical Representations and Smoothing of Curves and Surfaces

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The effects of deprivation of cigarette smoking on psychomotor performance∗

Increased restrictive action has been taken to limit tobacco smoking in a variety of public and occupational settings without regard to the behavioural effects of these actions on smokers. Two studies were undertaken; one examining the performance of 16 college female cigarette smokers under conditions of smoking or deprivation, and the second study investigating 16 males from the same population. Performance scores, taken from an instrumented complex psychomotor device, were adjusted for ability as determined from a training period on the device and then compared between smoking conditions. In both studies, deprived smokers performed significantly less well on the pursuit tracking task while reaction time, vigilance and mental arithmetic tasks were not affected. Results are discussed in terms of the negative effects on performance and the possible implications for work situations.     

The Processing and Improvement of Multi-Statement Queries in Chiql

Chiql is a novel Chinese relational database query language for Chinese users.It supports procedural query style in which users can specify a complex database request in multiple simple statements.This facility renders Chiql simple-to-use and easy-to-remember.However,direct execution of multi-statemen Chiql rueries(i.e.statement by statement)is often inefficient as potential index-based operations(e.g.join) are by-passed.Furthermore,it often incurs additional database operations,such as scan and projection.To improve this situation,the SMA(Statement Merging Algorithm)is proposed.The goal of SMA is to merge as many dependent statments within Chiql query as possible to form a more efficient Chiql query.The ability in achieving improved effciency without sacrificing the simplicity of the language is the major advantage of this algorithm.     

Naturality of the conditional and the recursion ∗

In a class of categories, including E. Manes's assertional ones, the control structures if-then-else and repeat-until are modeled as natural transformations of suitable functors. This context show how the three basic pieces of any structured programming language (concatenation, conditional and recursion) share naturality.     

Perceived Causes of Difficulty in Work Situations∗

Examples of difficult work situations were collected from five different types of jobs by interviewing panels of employees a number of times. The situational causes of difficulty, as perceived by the employees, were classified into a number of ' difficulty factors'. The importance of a factor for the difficulty of a certain job was measured in terms of its frequency in the interview records. Among three broad classes of factors—decision-making, interpersonal contacts, and time-and-energy resources—the decision-making factors had the highest frequency in all five jobs, but the pattern of individual factors differed among jobs. Correlation measures were also obtained, between the intensity of each factor and perceived difficulty, and between the sum of factor scores and perceived difficulty.     

Minimization of transmission cost in decentralized control systems†

This paper considers the problem of stabilizing a linear time-invariant multivariable system by using local feedback controllers and some limited information exchange among local stations. The problem of achieving a given degree of stability with minimum transmission cost is solved.     

The cost structure of influencers’ posts: the risk of losing followers

Personal and Ubiquitous Computing - This paper presents an exploratory study of the posting behavior of digital influencers in social participation platforms. As there are different platforms of...     

Effects of heel cushioning elements in safety shoes on muscle–physiological parameters

Safety shoe designs are primarily based on safety requirements. But all-day comfort should not be luxury: Heel strike associated impact loads on joints need to be compensated by active muscular effort and safety shoes should support this protective function of muscle activation. In 10 healthy men, 12 trunk and leg muscles were analyzed with surface electromyography. Subjects walked on a walkway while wearing different safety shoes with the test shoes being equipped with exchangeable cushioning heel inserts according to individuals' body weight. While wearing the optimally cushioned shoes the cumulative muscle activity per distance travelled dropped clearly compared to the regular safety shoes, demonstrating reduced muscular effort. Also, the heel strike associated amplitude peak of back muscles occurred earlier within the stride while wearing the test shoes. Thus weight-balanced cushioning heel inserts in safety shoes proved able to reduce muscle strain, logically delaying muscular fatigue and extending muscular joint protection.Relevance to industryAdjustable heel inserts in safety shoes are suited to improve the health status of employees by reducing muscular effort so that active joint protection can be prolonged.     

The development of ergonomics data for health-building design guidance∗

Abstract

Changes in policy and resources result in health-care systems which are constantly evolving. The evolution is reflected in physical and functional changes in health-building designs.

Building design guidance must be capable of accommodating these changes without losing its validity or usefulness. This paper discusses the development of an ergonomics (i.e. user oriented) data bank, linked to a checklist of component parts (i.e. items of furniture and equipment), whose effective and efficient use and interrelationship determines the form and planning of an effective and efficient health building.

The developed data system is seen as an effective tool for quality control, which can be applied at the drawing-board stage in health-building design, and which has previously not been available.     

The Design and Realization of Intelligent Loop-coil Detector in Traffic

1IntroductionWiththedevelopmentoftheeconomy,ITS(intelligentcommu-nicationsystem)wasbeingresearchedandattachedmoreimpor-tanceinChina.Asaimportantpartoftrafficinformationcollection,detectorswerepaidmoreandmoreattentionbyexperts.Vehicledetectorsaimattraffic-flowanddetectthepassingorexistenceofvehicles.itcanprovidesufficientinformationsothatthewholetraf-ficcontrolsystemcanobtaintheoptimalperformance.therearemanykindsoftrafficdetectorssuchasloop-coildetectors,videodetectors,microwavedetectorsands…     

The effects of running fewer subjects on time‐on‐task measures

There is a desire to streamline the development design process by conducting usability evaluations with fewer subjects. This study examined the impact of using fewer subjects on the accuracy and stability of the mean and median. Monte Carlo simulations were conducted to model the skewed task‐completion times typically found in usability studies. The results showed that the mean was a more accurate estimate of its respective population parameter than the median and should be the preferred metric in usability evaluations. However, the mean cannot always be used because it will underestimate the population mean when there are missing data as a result of subjects exceeding time limits. Alternatively, it was found that the median tended to consistently overestimate the population median by as much as 10% in one examined case. The average 95% confidence limits of both estimates were quite broad, particularly for the smaller sample sizes. Based on these results, it was concluded that with reduced sample sizes (e.g., 5), we are not able to measure population parameters with either a high degree of confidence or, in the case of medians, with any accuracy. It was recommended that usability measurements take a back seat to usability testing when conducting tests with small sample sizes.     

Solvers’ participation in crowdsourcing platforms: Examining the impacts of trust,and benefit and cost factors

Organizations are increasingly crowdsourcing their tasks to unknown individual workers, i.e., solvers. Solvers' participation is critical to the success of crowdsourcing activities. However, challenges exist in attracting solvers to participate in crowdsourcing. In this regard, prior research has mainly investigated the influences of benefit factors on solvers’ intention to participate in crowdsourcing. Thus, there is a lack of understanding of the cost factors that influence actual participation behavior, in conjunction with the benefits. Additionally, the role of trust in the cost-benefit analysis remains to be explored. Motivated thus, based on social exchange theory and context-related literature, we develop a model to explain the impacts of benefit and cost factors as well as trust on solver participation behavior in crowdsourcing. The model was tested using survey and archival data from 156 solvers on a large crowdsourcing platform. As hypothesized, monetary reward, skill enhancement, work autonomy, enjoyment, and trust were found to positively affect solvers’ participation in crowdsourcing, while cognitive effort negatively affects their participation. In addition, it was found that monetary reward positively affects trust (trust partially mediates its effect on participation behavior), while loss of knowledge power negatively affects trust. The theoretical contributions and practical implications of the study are discussed.     

The “problem” in and of management information systems

Management Information Systems uncritically draws upon a number of disciplines for its theoretical framework. In doing so it has imported a host of ontological, epistemological and behavioral assumptions which have shaped the theories, technologies and practices of information system analysis, design and implementation. This has taken place without careful reflection upon the historical emergence of these assumptions or upon the context within which attempts are made to operationalize them. This paper argues that the Management Information Systems field is in need of researching itself. It proposes that through a combination of genealogical and ethnographic research methodologies, the historical emergence of theoretical constructs and the organizational context within which information systems operate should be critically examined. In the following analysis, the historical emergence of the “problem” as a generic construct in the Management Information System literature is examined and contrasted to the manner in which a group of manufacturing managers defined problems within their organizational context. A critical tension is revealed which suggests that information systems researchers, analysts and designers need to at least broaden their assumption about the nature of organizational reality, human behavior, information processing and problem solving.     

Representations of lesbian and bisexual women’s sexual and relational health in online video and text-based sources

The Internet is the preferred source of health information followed by healthcare providers, friends and family, print media, and television (Baxter & Egbert, 2008). Yet, previous research about online sexual health resources for LGBTQ (lesbian, gay, bisexual, transgendered, queer) groups, especially lesbian and bisexual (LB) women, primarily consists of introductions and reviews of related websites rather than critique of the quality of the information present (e.g. Clark, 2003; Finlon, 2002; McKay, 2011). Thus, the goals of this study were to examine the LB women’s sexual and relational health content in online sources and identify the degree to which the online sources considered LB women’s identity and standpoint when presenting sexual and relational health messages. The analysis includes a comparison of text-based and video-based online messages related to LB women’s sexual and relational health. We argue that there is an overall lack of quality in the online sexual and relational health messages for LB women, and that websites are not comprehensive enough in their coverage of LB women’s sexual and relational health.