EPR制度下废弃电子产品回收的低碳研发激励机制研究

在由生产者与研发方组成的两阶段闭环供应链体系中,考察生产者延伸责任制(EPR)对产品低碳研发设计的激励作用以及对废弃电子产品回收的减排效果.以生产商为Stackelberg博弈领导者,设计预先承诺收益分配比例的S-S模型和延迟承诺S-N模型,并给出两种模型的最优契约决策.研究发现,研发方的低碳研发技术水平、碳税税率、双方在回收减排中的重要度都会对契约决策和回收减排产生影响,在系数满足一定条件下,两种模型的回收减排效果各有优势.     

Self-administered questionnaire and direct observation by checklist: comparing two methods for physical exposure surveillance in a highly repetitive tasks plant

Background

We evaluated the agreement between a questionnaire and an observational checklist for exposure assessment in the setting of an upper-limb work-related musculoskeletal disorders (UWMSD) surveillance program in a population with a high level of physical exposures.

Methods

A surveillance program was implemented in a large shoe factory. Physical exposures were assessed in 1996 by a self-administered questionnaire and by the direct observation of work tasks assessed using a checklist filled out by trained assessors. Items were summed into a “questionnaire” score and an “observational” score. These scores were compared by Pearson's correlation. The association between exposure assessment by each method and UWMSD incidence between 1996 and 1997, defined by a standardized examination, was also studied.

Results

Correlation between the “questionnaire” score and the “observational” score was low among the 196 workers (77%) who received both evaluations (rho=0.06, p>0.05). Only exposure assessed by the questionnaire method was significantly associated with high incidence of UWMSD between 1996 and 1997, with good sensitivity (97%) and poor specificity (27%).

Conclusion

In this surveillance program, self-reported physical exposures assessed by questionnaire and by direct observation did not evaluate same dimensions of high physical exposures. In this sample, exposures assessed by questionnaire identified workers at high risk of incident UWMSD more precisely than exposures identified by direct observation.     

Sir Frederic Bartlett: 1886—1969 A PERSONAL HOMAGE

Abstract

Fatigue was measured on 68 air traffic controllers using the following methods: critical fusion frequency (CFF), tapping test, grid tapping test, self-rating. The measurements were taken 9 times within 24 hours over 3 weeks. Stress was measured on the basis of a questionnaire and of catecholamine excretion in urine. The four fatigue tests showed significant agreement. There was a marked decrease in the values after the 6th hour of work. During the night hours, the test values were lower, and the subjects stated they were more tired. For the first work hour and for the 9th to 11th work hour Spearman's correlation coefficients between the two sets of data were calculated. A significant correlation was found (a) between CFF and grid tapping (p<0·02); (b) between CFF and self-rating ‘ refreshed-tired ’ (p<0·05); (c) between grid tapping and self-rating ‘ refreshed-tired ’ (p<0·02). This means that subjects with a marked decrease in CFF or in grid tapping performance have a greater tendency to ‘ tired ’ in the self-rating test. On the basis of this finding it might therefore be hypothesized that all measures are indicative of a common state of fatigue.

Results of the questionnaire (62 subjects): in difficult situations 60 subjects felt nervous, tense, irritated, 13 were anxious and trembling, 19 had increased perspiration, 14 had increased pulse rate and heart ache, 25 suffered from insomnia and chronic fatigue.

Urine samples front 6 subjects were taken after normal office work, easy ground control work, and radar air traffic control. There was a significant increase in the catecholamines in the last condition.     

Effects of a standing and three dynamic workstations on computer task performance and cognitive function tests

Sedentary work entails health risks. Dynamic (or active) workstations, at which computer tasks can be combined with physical activity, may reduce the risks of sedentary behaviour. The aim of this study was to evaluate short term task performance while working on three dynamic workstations: a treadmill, an elliptical trainer, a bicycle ergometer and a conventional standing workstation. A standard sitting workstation served as control condition. Fifteen Dutch adults performed five standardised but common office tasks in an office-like laboratory setting. Both objective and perceived work performance were measured. With the exception of high precision mouse tasks, short term work performance was not affected by working on a dynamic or a standing workstation. The participant's perception of decreased performance might complicate the acceptance of dynamic workstations, although most participants indicate that they would use a dynamic workstation if available at the workplace.     

融合多模态深度游走与偏差校准因子的推荐模型

曝光偏差严重影响协同过滤模型的推荐精度,导致预测结果偏离用户的真实兴趣,而现有模型对曝光偏差的建模能力有限,甚至放大偏差。为此,提出融合多模态深度游走与偏差校准因子（MmDW-BC）的推荐模型。首先,引入项目多模态属性特征作为项目图的连接边,从而缓解低曝光项目交互数据稀疏的问题;在此基础上,构建图嵌入模块——多模态深度游走（MmDW）将项目多模态信息融入嵌入向量,以获取丰富的节点表示;最后,基于校准策略设计新的偏差校准推荐算法进行用户偏好预测。将提出的模型应用于Amazon和ML-1M数据集上,实验结果验证所提模型明确考虑曝光偏差来提升推荐精度的必要性和有效性。     

Daily living activities in older adults: Part II—effect of age on physical activity patterns in older Mexican American adults

This paper, the second of a two-part paper, reports results from an experimental study conducted to understand physical activity patterns, and determine the effect of age on physical activity patterns in older Mexican American adults. The Yale Physical Activity Survey was administered to 49 older Mexican American adults (42 females and seven males), aged 68–80 years, recruited from senior recreation centers in the city of El Paso. Based on participant responses to questions about the type and duration of different types of physical activities, overall physical activity indices including the total time (h/week), the total energy expenditure (kcal/week), a summary index score, a vigorous activity score (units/month), a leisurely walking score (units/month), a moving score (units/month), and a standing and sitting score (both in units/month) were computed. These responses were then regressed with age (as the predictor variable). Since the number of older males in the study was small, data from men and women were combined. Results indicate that the standing score index (p<0.1) and the sitting score index (p<0.05) are linearly related to age. None of the other Yale Physical Activity Survey indices including the total time index and the weekly energy expenditure index are linearly related to age. Fitted line plots for Yale indices that do not show a linear relationship with age indicate that total time, energy expenditure, leisurely walking index score, and summary index score, all have a quadratic fit with age. A cubic fit is indicated for the vigorous activity score and the moving index score.

Relevance to industry

Understanding physical activity patterns (both work and leisure activities in daily living) in older adults is important for estimation of activity metabolism for among older adults.     

Daily living activities in older adults: Part I—a review of physical activity and dietary intake assessment methods

The aging process is expected to change advanced activities of daily living (such as employment and work activities), to basic activities of daily living (BADL; such as self-care activities, which is also considered work among older adults). In effect, older adults spend more energy on physical activities related to BADL, compared to heavy physical activity in any industrial work. Hence, accurate assessment of the type and extent of physical activity becomes critical for estimation of the activity metabolism, especially in older adults. Once an assessment of activity metabolism is made, energy balance can be quantified by comparing energy expenditure (including resting activity, and digestive metabolism) with caloric intake. Instruments and techniques available to quantify physical activity in older adults, and caloric intake in older adults are reviewed in this paper. The emphasis in this review is on questionnaire-based instruments that minimize burden on the investigator and the participant. Validity and reliability of the assessment instruments are also discussed.

Relevance to industry

Since most work activities requiring energy expenditure among older adults, especially retirees, consist of BADL, accurate assessment of activity metabolism and dietary intake is necessary for designing these work activities for older adults.     

A systematic review – physical activity in dementia: The influence of the nursing home environment

Most older persons with dementia living in nursing homes spend their days without engaging in much physical activity. This study therefore looked at the influence that the environment has on their level of physical activity, by reviewing empirical studies that measured the effects of environmental stimuli on the physical activity of nursing home residents suffering from dementia. The electronic databases PubMed, PsycINFO, EMBASE, CINAHL and the Cochrane Library were used for the search. The search covered studies published between January 1993 and December 2012, and revealed 3187 abstracts. 326 studies were selected as potentially relevant; of these, 24 met all the inclusion criteria. Positive results on the residents' levels of physical activity were found for music, a homelike environment and functional modifications. Predominantly positive results were also found for the small-scale group living concepts. Mixed results were found for bright or timed light, the multisensory environment and differences in the building footprint.     

The accuracy of self-report and trained observer methods for obtaining estimates of peak load information during industrial work

The purpose of this study was to determine how well self-report (questionnaire=QR) and trained observer (checklist=OBS) data recording methods compared with more expensive video analysis (VID) for estimating various peak physical loading exposure variables on the low backs of 99 employees during work in an automobile assembly plant. The variables studied were L4/L5 spine compression and shear forces, L4/L5 moment, trunk angle, and hand load. Peak low back loads associated with the working postures of, and the applied loads on, each worker were estimated using a 2D biomechanical model that could accommodate inertial forces acting in various directions on the hands independently. Correlations between the VID and OBS methods were greater for each variable than between VID and QR methods, with ranges in coefficients from 0.6 to 0.8, and 0.1 to 0.4, respectively, giving a discouraging impression of the QR, and the OBS method to a lesser degree, for peak low back exposure assessment. Despite the better performance of OBS method for individuals, it was still only able to account for between 36% and 64% of the variance relative to the VID method. When all workers were considered as a single group, compression and shear forces, moment and hand load estimates were the same regardless of method used to collect the data. Self-reported trunk flexion was significantly greater than that reported by trained observers or on video (p<0.0001).Relevance to industryConsiderable time and expense could be saved in large scale studies if it were possible to rely on worker's reports or observation of the physical demands of their jobs instead of traditional video and biomechanical analyses. Assessments of peak exposure of individuals using the self-report and observation methods were discouraging. Analysis of a single group proved more promising, but other groups need to be studied. Interview assisted self-reports may help to improve assessments of individuals and also need to be investigated in the future.     

Rationalization in meat cutting - consequences on physical workload

Meat cutting is associated with several ergonomic risk factors and a high risk of musculoskeletal disorders. The development of new production systems points to an increased degree of mechanization; instead of subdividing split carcasses of pigs with a knife, the halves are trisected by an electrical saw into 'sixth-parts', resulting in shorter work cycles for the workers. Recently, machine-directed line-production systems have been implemented. This study evaluates differences in the physical workload between the production systems. The postures and movements (inclinometry and goniometry) and muscular load (electromyography) of workers in the split-carcass- (five subjects), sixth-part- (ten) and line-production systems (five) were recorded. Most measures showed a statistically significant trend of declining physical exposure with increasing degrees of mechanization. For example, movement velocities of the upper arm were higher in the split-carcass system (50th percentile: mean 209°/s) than in the sixth-part (103°/s) and line production (81°/s). However, the latter two were not statistically significantly different. A novel method for quantifying posture variation, based on inclinometry, showed that the split-carcass system implied the highest variation of the upper arm postures "within-minute" (i.e., a high range of motion each minute), but the lowest "between-minute" (i.e., a low variation during the course of the workday). In conclusion, the physical workload in the line-production system was significantly lower than in the split-carcass one, and tended also to be lower than in the sixth-part system. However, there may be disadvantages in line production, such as machine-directed work pace and shorter work cycles.     

Musculoskeletal disorder prevalence and psychosocial risk exposures by age and gender in a cohort of office based employees in two academic institutions

This study presents data on self-reported prevalence of Musculo-Skeletal Disorder (MSD) symptoms and psychosocial risk exposures by age and gender among a group of office based University workers who use their computers for at least 25% of their workday. Employees in two academic organisations received an invitation to participate in an on-line questionnaire. A total of n = 852 office workers participated in this study; yet respondents who were employed for greater than 12 months were only included in the study cohort. Furthermore, participants were only considered for further analysis if they spent 50% or more of their workday in their office, and of this time at least 50% was spent on computer work (n = 569). The study indicates that self-reported symptoms of MSDs for these workers were highest in the neck, shoulder and lower back. Neck, shoulder and back MSDs were higher for females than males, yet age differences within genders were not evident for these symptoms. For neck disorders, symptomatic individuals reported significantly higher levels of office work (p < 0.05) and PC usage (p < 0.005), and significantly lower levels of job content (p < 0.01), job demands (p < 0.05), and work environment (p < 0.05) compared to asymptomatic participants. For the shoulder, symptomatic individuals exposure levels were significantly higher for office work (p < 0.05) and PC usage (p < 0.05) and significantly lower for job content (p < 0.05) compared to asymptomatic individuals. There was evidence of important differences in the psychosocial exposures between age and genders, but associations between these differences and MSD symptoms were not present.Relevance to industryThis study presents prevalence data on age and gender differences in self-reported symptoms of MSDs and psychosocial risk exposures in a group of sedentary workers.     

Utility of the RT3 triaxial accelerometer in free living: An investigation of adherence and data loss

There is strong evidence for the protective effects of physical activity on chronic health problems. Activity monitors can objectively measure free living occupational and leisure time physical activity. Utility is an important consideration when determining the most appropriate monitor for specific populations and environments. Hours of activity data collected, the reasons for activity hours not being recorded, and how these two factors might change over time when using an activity monitor in free living are rarely reported. This study investigated user perceptions, adherence to minimal wear time and loss of data when using the RT3 activity monitor in 21 healthy adults, in a variety of occupations, over three (7 day) repeated weeks of measurement in free living. An activity diary verified each day of monitoring and a utility questionnaire explored participant perceptions on the usability of the RT3. The RT3 was worn for an average of 14 h daily with 90% of participants having complete data sets. In total 6535.8 and 6092.5 h of activity data were collected from the activity diary and the RT3 respectively. An estimated 443.3 h (6.7%) of activity data were not recorded by the RT3. Data loss was primarily due to battery malfunction (45.2%). Non-adherence to wear time accounted for 169.5 h (38.2%) of data loss, of which 14 h were due to occupational factors. The RT3 demonstrates good utility for free living activity measurement, however, technical issues and strategies to manage participant adherence require consideration with longitudinal and repeated measures studies.     

Physical activity levels among adult computer users

As computer use becomes prevalent at work and in leisure pursuits it presents a potential barrier to regular physical activity. However an individual’s confidence in overcoming such barriers may moderate the relationship between computer use and physical activity levels. This study examined the associations among computer use, self-efficacy in overcoming barriers to exercise, and physical activity levels among adult computer users. Participants (N = 615) were recruited through national email and newsletters announcements, and completed standardized self-report questionnaires online. Computer use was not associated with meeting physical activity guidelines (adjusted odds ratio, AOR = 0.63-1.00, n.s.). Among leisure computer users, the moderate efficacy group (AOR = 3.72, 95% CI = 1.59-8.69) and the high efficacy group (AOR = 5.31, 95% CI = 2.37-11.91) had higher odds of meeting physical activity guidelines compared to the low efficacy group. Among the work related computer users, the high efficacy group (AOR = 2.83, 95% CI = 1.18-6.77) had higher odds of meeting physical activity guidelines than the low efficacy group. These results suggest that barriers posed by high levels of computer use are surmountable. Efforts to increase efficacy in overcoming barriers to exercise may be more practical and have a greater impact on physical activity levels than trying to decrease computer use among adults.     

The Pikachu effect: Social and health gaming motivations lead to greater benefits of Pokémon GO use

Several studies provided evidence for the effectiveness of gamification of health behaviors (e.g., exercising or walking) via video games. However, little is known about whether individuals who endorse specific gaming motivations are more likely to derive health benefits from gaming. Building upon previous studies on gamification of health behaviors, we examined whether specific gaming motives (e.g., potential health benefits) influenced Pokémon GO gaming time and gaming health outcomes, a phenomenon we termed The Pikachu Effect. We introduced health motivation as a novel component among previously established gaming motives, which reflects the ongoing gameplay transformation and increased health potential of modern games. Volunteers (N = 444) completed two measurements of Pokémon GO motivations, gaming time, physical activity, and time spent outdoors within a 6 week interval. The results supported the Pikachu effect hypothesis as health motivation and social motivation were related to health outcomes. Furthermore, we replicated previous findings indicating that individuals who spent more time playing Pokémon GO were more physical active. We also evidenced a new Pokémon GO playing behavioral benefit, i.e., increased time spent outdoors among more active players. We explored meaningful individual differences; for example, men played more and derived more benefits from Pokémon GO. These findings suggest that health motivation operates in parallel with previously identified main motives for gaming. Accounting for motivation is essential for a more accurate prediction of gaming time and gaming-related health behaviors.