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THE RELATION BETWEEN EVOLUTION OF SPATIAL WORKING MEMORY FUNCTION AND OF MORPHOLOGY OF THE DORSOLATERAL PREFRONTAL CORTEX AMONG THE RHESUS MONKEY, SLOW LORIS AND TREE SHREW 被引量:1
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作者 蔡景霞 徐林 +3 位作者 胡新天 马原野 苏卫 肖昆媛 《Zoological Research》 CAS CSCD 1993年第2期158-165,共8页
The relation between evolution of spatial working memory function and of morphology of the dorsolateral prefrontal cortex among the rhesus monkey (Macaca mulatta), the slow loris (Nycticebus coucang) and the tree shre... The relation between evolution of spatial working memory function and of morphology of the dorsolateral prefrontal cortex among the rhesus monkey (Macaca mulatta), the slow loris (Nycticebus coucang) and the tree shrew (Tupaia belangen chinensis) were reported in present paper. The results read as follows: In the DR performance with training, the rhesus monkeys and slow lorises could reach a criterion of 90% correct response at 1.1 ± 3.2 seconds, and 3.8±0.4 seconds delay interval, respectively, by 1000 training trails. The tree shrews failed to reach the criterion of 90% correct response even at 0 seconds delay interval by 1000 training trails. If a delay interval was tested in one session (30 trails) only, doing the DR performamce without training, the rhesus monkeys reached a correct of 80% or higher in each session at 0, 1, 2, 3, 4, and 5 seconds delay, respectively. The percent correct in each session of the slow lorises showed no differences from the rhesus monkeys at 0, 1, 2, 3, and 4 seconds delay. However, when the delay interval was increased to 5 seconds, the percent correct of the DR performance declined to 70% or lower in the slow lorises. In the tree shrews the percent correct in each session reached to 70% or lower at 0, 1, 2, 3, 4, and 5 seconds delay interval, respectively. The morphological studies revealed that the size of the prefrontal cortex increased, and the structure got complex in the course of the evolution in primates. It is suggested that the relation of evolution between the spatial working memory function and anatomy in the prefrontal cortex might be significant among the three species, both the development of morphology and that of the spatial working memory function in the dorsolateral prefrontal cortex are later than other regions of cerebral cortex in phylogenetic evolution course. 展开更多
关键词 Spatial working memory Prefrontal cortex MORPHOLOGY EVOLUTION relation Macaca mulatta Nycticebus coucang Tupaia belangeri chinensis
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On Answering the Question Related to the Legal Regulation of Working Hours in the New Era:Western Experience and Chinese Approach
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作者 曹燕 XU Chao 《The Journal of Human Rights》 2023年第1期157-181,共25页
The popularity of flexible working hours around the world has slowed down the historical trend of reducing working hours.It even shows signs of regression.Whether and how to guide the cur-rent society with flexible wo... The popularity of flexible working hours around the world has slowed down the historical trend of reducing working hours.It even shows signs of regression.Whether and how to guide the cur-rent society with flexible working hours to return to the historical track of reducing working hours,improve the quality of working hours,and promote a smooth transition from the era of traditional standard work-ing hours to the era of flexible working hours has become a question related to the legal regulation of working hours in the new era.In this regard,although Western countries have proposed new regulatory concepts and carried out legislative practices with distinctive charac-teristics,the limitations of legal regulation capabilities have prevented them from proposing a package of institutional solutions.The advan-tage of China in the ability of legal regulation of working hours has been gradually formed in the legislation on working hours unnder the leadership of the CPC in the past century.It enables China to break through the limitations of the West and propose a Chinese approach to answer the question of the legal regulation of working hours in the new era from three aspects:limiting the extension of working hours,improving the quality of flexible working hours,and optimizing the funnctions of the multi-funnctional regulatory system for working hours. 展开更多
关键词 question related to the legal regulation of working hours in the new era flexible working hours Chinese approach decent working hours quality of working hours working hours capability balanced working hours
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Epidemiological Patterns of Work-Related Musculoskeletal Disorders among Healthcare Workers in Five Reference Hospitals in the City of Douala, Cameroon
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作者 Basil Kum Meh Orélien Sylvain Mtopi Bopda +7 位作者 Jerson Mekoulou Ndongo Franklin Chu Buh Claude Elysée Bika Léle Clarisse Noël Ayina Ayina Peguy Brice Assomo Ndemba Emmanuel Haddison Sako Bienvenu Bongue Samuel Honoré Mandengue 《Open Journal of Preventive Medicine》 CAS 2023年第5期109-128,共20页
Introduction: Work-related musculoskeletal disorders (WRMSDs) are a public health problem and have forced many workers to quit their jobs prematurely. This study investigated the prevalence and risk factors of WRMSDs ... Introduction: Work-related musculoskeletal disorders (WRMSDs) are a public health problem and have forced many workers to quit their jobs prematurely. This study investigated the prevalence and risk factors of WRMSDs among Healthcare workers in five reference hospitals in the City of Douala-Cameroon. Methods: A cross-sectional study was conducted in 2022 among 561 healthcare workers working in five reference hospitals in the city of Douala, Cameroon. Participants were selected using a convenient sampling technique. Data were collected with structured questionnaires;data on the demographics and risk factors were collected using a well-designed questionnaire, while estimation of the prevalence of WRMSDs was done using the Modified Nordic questionnaire. Results: The overall prevalence rate of WRMSDs among healthcare workers in Douala hospitals was 83.4% (468/561). The prevalence per professional groups was as follows: 88.8% (71) for Medical Laboratory Scientists (MLS), 81.9% (289) for nurses, 21 (80.8%) for Physiotherapists (PTs) and 78.8% (41) for Medical Doctors (MDs). There was a significant difference (p = 0.001) in the prevalence of WRMSDs with respect to place of work where healthcare workers from HLD recorded the highest prevalence 89.9%, while Healthcare workers from NBDH were 2.91 times at risk (AOR = 2.91;95% CI: 1.32 - 6.41;p = 0.001) to develop WRMSDs than healthcare workers in the other hospitals. With respect to body region, the highest prevalence of WRMSDs was recorded on the lower back, 58.8% with the lowest at the elbows 11.2%. The age group 30 to 39 years was significantly associated with WRMSDs at level of the shoulder (p = 0.002), upper back (p = 0.019), elbows (p Conclusion: The overall prevalence rate of WRMSDs among healthcare workers in Douala hospitals was high. The prevalence of WRMSDs is highest among MLS and nurses and the most affected body parts are;lower back, neck and upper back. Working on the same posture, stressful job, and repetitive tasks were the major risk factors associated to WRMSDs among healthcare workers in Douala hospitals. 展开更多
关键词 work-Related Musculoskeletal Disorders Risk Factors PREVALENCE Healthcare workers Douala-Cameroon
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Prevalence of Work-Aggravated Asthma among Bakery Workers in Abidjan (Cote d’Ivoire)
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作者 Loukou Leandre Konan Esme Marie Laure Essis +5 位作者 Brou Michel Kouassi Marius Kedote Julius Fobil William Yavo Ossey Bernard Yapo Issaka Tiembre 《Health》 2024年第3期204-217,共14页
Introduction: Work-aggravated asthma is pre-existing or concomitant asthma whose symptoms are aggravated by the work environment. The aim of this study was to determine the prevalence of this pathology and its associa... Introduction: Work-aggravated asthma is pre-existing or concomitant asthma whose symptoms are aggravated by the work environment. The aim of this study was to determine the prevalence of this pathology and its associated factors among bakery workers in Abidjan. Materials and Methods: This descriptive and analytical cross-sectional study was conducted over a period of four (4) months from 18 December 2019 to 18 April 2020. Two questionnaires were used, one on employees and the other on the indoor environment of bakeries. In addition, a spirometry test was performed on all bakery workers. Statistical analysis was performed using stata 15.1 software. Results: A total of 599 bakery employees, including bakers (59.73%), sales assistants/ cashiers (23.52%), cleaners (6.34%) and administrative staff (10.18%), were investigated. The mean age was 30.8 ± 8 years, with a sex ratio (M/F) = 2.2. Asthma symptoms were found in 95 (15.86%) employees, of whom 74 (77.9%) had work-related asthma and 11 (14.9%) had asthma aggravated by work. The factors associated with work-aggravated asthma were personal or family history of allergy or atopy [ORa = 3.75;CI95%: 1.56 - 8.93;p = 0.003], exposure to dust [ORa = 5.01;CI95%: 1.43 - 7.50;p = 0.011] and humidity level (60% - 70%) [ORa = 1.80;CI 95%: 0.99 - 3.28;p = 0.05]. Conclusion: Work-aggravated asthma is a reality in bakeries in Abidjan, with an estimated prevalence of 14.9%. Two of the three factors associated with this condition suggest a link with indoor air pollution. Combating air pollution in these establishments must therefore be a priority for the relevant authorities, in order to provide employees with a working environment that protects their health. 展开更多
关键词 work-Aggravated Asthma Occupational Asthma work-Related Asthma BAKERIES ABIDJAN Ivory Coast
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On the 2002 U. S. Mid-Term Election Zhang Yanyu and Wang Wenfeng are both assistant research professors at the Division for American Studies in China Institute of Contemporary International Relations 被引量:3
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作者 Zhang Yanyu Wang Wenfeng 《Contemporary International Relations》 2002年第12期41-56,共16页
The first mid-term election of the U. S. in the new century took place on November 5, 2002. One third of the senators from the 107th Congress (34 out of 100), all representatives (435), 36 state governors, and numerou... The first mid-term election of the U. S. in the new century took place on November 5, 2002. One third of the senators from the 107th Congress (34 out of 100), all representatives (435), 36 state governors, and numerous local officials and legislators were to be elected or reelected. The resounding victory of the GOP in the congressional elections and the fact that the Democrats only got three more. 展开更多
关键词 Mid-Term Election Zhang Yanyu and Wang Wenfeng are both assistant research professors at the division for American Studies in China Institute of Contemporary International relations On the 2002 U ZHANG WANG
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ANNUAL WORKING REPORT OF CAS DIVISION OF MATHEMATICS & PHYSICS (Abridged) 被引量:1
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作者 Wang Shouguan CAS member and director of the CAS Division of Mathematics & Physics. 《Bulletin of the Chinese Academy of Sciences》 1997年第1期11-15,共5页
Ⅰ. ACADEMIC ASSIGNMENTS ACHIEVED 1. Hosted Key State-entrusted Consultancy Projects: (1) Completion of the advisory service which had been set for the national Eighth Five-year Plan entrusted by the national authorit... Ⅰ. ACADEMIC ASSIGNMENTS ACHIEVED 1. Hosted Key State-entrusted Consultancy Projects: (1) Completion of the advisory service which had been set for the national Eighth Five-year Plan entrusted by the national authorities. (2) Achievement of the consultancy work for key programs of basic research also entrusted by 展开更多
关键词 CAS ANNUAL workING REPORT of CAS division of MAtheMATICS Abridged PHYSICS
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Investigating the relationships between facets of work task and selection and query-related behavior 被引量:3
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作者 Yuelin LI 《Chinese Journal of Library and Information Science》 2012年第1期51-69,共19页
Purpose: This study aims to explore the relationships between different facets of work task and selection and query-related behavior.Design/methodology/approach:An experiment was conducted to explore the issue. The re... Purpose: This study aims to explore the relationships between different facets of work task and selection and query-related behavior.Design/methodology/approach:An experiment was conducted to explore the issue. The researcher recruited 24 participants and assigned six simulated work task situations to each of them. Each experiment lasted around 2 hours and was recorded by the software tool Morae.Findings: Time(frequency) and time(length) are more closely related to user’s selection and query-related behavior compared to the facet ‘process’ of work task. Knowledge level of work task topic, degree of work task difficulty, and subjective work task complexity are significantly correlated with selection and query-related behavior. Work task difficulty and work task complexity are different concepts. Subjective work task complexity, work task difficulty, and knowledge of work task topic are significantly correlated with user’s selection and query-related behavior.Research limitations/implications: The limitations of this study include a small sample size,limited work task situations, and possible spurious relationships. This study has implications in informing task-based information seeking/search/retrieval research and interactive information retrieval(IIR) systems design.Originality/values: Previous studies usually did not touch upon how different facets of work tasks affected interactive activities. Some studies examining task complexity and information behavior were concerned with how work tasks affect users’ behavior at information-seeking level, rather than at information search level. This study makes contribution to interactive information retrieval,task-based information search and retrieval, and personalization of IR. 展开更多
关键词 work tasks Facets of work tasks Selection behavior Query-related behavior Interactive information search behavior
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A Review of Academic Divisions'Work over the Past Two Years
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《Bulletin of the Chinese Academy of Sciences》 2000年第2期84-86,共3页
In line with the overall Objectives set out in the"Outline Scheme for the Academic Divisions of theChinese Academy of Sciences (CAS) during theNinth Five-year Plan (1996-2000)," CAS has donea good job of the... In line with the overall Objectives set out in the"Outline Scheme for the Academic Divisions of theChinese Academy of Sciences (CAS) during theNinth Five-year Plan (1996-2000)," CAS has donea good job of the supplementary election of CASmembers and the development of the virtues ofscience and fine style of research. In addihon, con-sultation and appraisal, academic exchanges, andthe popularization of science have progressivelybeen focuses of the academic divisions, and manyaccomplishments have been achieved in these areas. 展开更多
关键词 CAS A Review of Academic divisions’work over the Past Two Years work OVER
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Role of Rehabilitation Counseling and Psychology in Working with Individuals with Work-related Chronic Pain Injuries: An Interdisciplinary Approach-Chronic Pain and Work Injuries in the United States
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作者 Gloria K. Lee 《中国康复理论与实践》 CSCD 2006年第9期753-757,共5页
This paper addresses the topic of an interdisciplinary approach of chronic pain management from a biopsychosocial perspective. The first section provides an introduction to the definitions and theories of chronic pain... This paper addresses the topic of an interdisciplinary approach of chronic pain management from a biopsychosocial perspective. The first section provides an introduction to the definitions and theories of chronic pain and the various contributing factors (psychological, interpersonal/environmental and social support, and vocational). The second section presents the role of various health care professions (medical doctors, nurses, physical therapists, occupational therapists, psychologists and rehabilitation counselors) and the evidence of their treatment effectiveness. The third section discusses the concept of an interdisciplinary pain rehabilitation program (IPRP) and its evidence to support its effectiveness. Finally, the clinical implications of rehabilitation counseling and psychology as part of the inter-disciplinary program in treating individuals with chronic pain will be highlighted. 展开更多
关键词 chronic pain work-RELATED REHABILITATION PSYCHOLOGY COUNSELING interdisciplinary approach
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What Is the Role of Work-Related Factors in Self-Reported Health Inequalities among Employed Individuals? A Longitudinal Study in Luxembourg
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作者 Anastase Tchicaya Nathalie Lorentz Kristell Leduc 《Health》 2018年第9期1141-1158,共18页
Objectives: We measured health inequalities among employed Luxembourg residents over time and the socio-economic and work-related determinants. Design and Setting: Longitudinal data were obtained from the Socio-econom... Objectives: We measured health inequalities among employed Luxembourg residents over time and the socio-economic and work-related determinants. Design and Setting: Longitudinal data were obtained from the Socio-economic Liewen zu L&#235;tzebuerg/European Union Survey on Income and Living Conditions, which has been conducted each year since 2003 in Luxembourg. Participants: Participants comprised 727 Luxembourg residents (58% men), aged between 21 and 55 years in 2003, who were employed between 2003 and 2012. Primary and Secondary Outcomes Measured: The variable of interest was self-reported health. We used transition indicators on work-related factors to consider changes that individuals may have experienced in their job over this period. Results: People who moved from a part-time to a full-time contract (odds ratio (OR): 5.52, confidence interval (CI): 1.55 - 19.73), and those who moved from the 3rd or 4th quartile of earnings to the 1st or 2nd quartile (OR: 2.48, CI: 1.02 - 6.05) between 2003 and 2012, had a higher risk of being in poor health in 2012. The risk of deterioration in self-reported health in 2012 among people who were healthy in 2003 was associated with the type of contract, economic activity, and occupation. Conclusion: Health inequalities occur among employed people in Luxembourg. Their importance varies according to work-related characteristics and economic activity. Our findings showed that declined health status was associated with contract type, profession, and economic activity. This suggests that measures should be taken to maintain good health for people working in these specific occupations or economic sectors (e.g. preventive action, reduction of risk exposure, change of occupation in the same company, and so on). 展开更多
关键词 Employment HEALTH Inequalities working Conditions EU-SILC work-RELATED Factors SELF-REPORTED HEALTH
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Long-Term Electrophysiological and Behavioral Analysis on the Improvement of Visual Working Memory Load, Training Gains, and Transfer Benefits
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作者 Ching-Chang Kuo Cheng Zhang +1 位作者 Robert A. Rissman Alan W. L. Chiu 《Journal of Behavioral and Brain Science》 2014年第5期234-246,共13页
Recent evidence demonstrates that with training, one can enhance visual working memory (VWM) capacity and attention over time in the near transfer tasks. Not only do these studies reveal the characteristics of VWM loa... Recent evidence demonstrates that with training, one can enhance visual working memory (VWM) capacity and attention over time in the near transfer tasks. Not only do these studies reveal the characteristics of VWM load and the influences of training, they may also provide insights into developing effective rehabilitation for patients with VWM deficiencies. However, few studies have investigated VWM over extended periods of time and evaluated transfer benefits on non-trained tasks. Here, we combined behavioral and electroencephalographical approaches to investigate VWM load, training gains, and transfer benefits. Our results reveal that VWM capacity is directly correlated to the difference of event-related potential waveforms. In particular, the “magic number 4” can be observed through the contralateral delay amplitude and the average capacity is 3.25-item over 15 participants. Furthermore, our findings indicate that VWM capacity can be improved through training;and after training exercises, participants from the training group are able to dramatically improve their performance. Likewise, the training effects on non-trained tasks can also be observed at the 12th week after training. Therefore, we conclude that participants can benefit from training gains, and augmented VWM capacity sustained over long periods of time on specific variety of tasks. 展开更多
关键词 VISUAL working Memory EVENT-RELATED Potential COGNITIVE TRAINING
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The Naples-Questionnaire of Work Distress (nQ-WD): Bullying at workplace, organizational dysfunctions and bio-psycho-social effects
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作者 Giovanni Nolfe Maria Triassi +2 位作者 Antonella Cappuccio Umberto Carbone Giuseppe Nolfe 《Open Journal of Psychiatry》 2012年第1期77-81,共5页
The aim of this study is to elaborate a tool, the “Naples-Questionnaire of Work Distress” (nQ-WD), in order to evaluate the conditions of discomfort perceived in the working field. It tries to differentiate the dysf... The aim of this study is to elaborate a tool, the “Naples-Questionnaire of Work Distress” (nQ-WD), in order to evaluate the conditions of discomfort perceived in the working field. It tries to differentiate the dysfunctional phenomena more tied to the anomalies of the interpersonal relationships (bullying at work-place) from the phenomena more clearly related to organizational dysfunctions. The inventory measures the overall effects of these two areas on the subject and the spin-off in term of bio-psycho-social functioning. The questionnaire has been administered to a group of 178 workers who showed a work-related psychopathological disturbance and to a control group of 178 subjects without exposure to bullying at workplace or to organizational distress. The statistical analysis demonstrated degree of significant validity and reliability. The degree of internal coherence of the answers proposed is satisfactory. The ROC curves allow the determination of a threshold value which allows separating the workers subjected to mobbing and/or organizational stress from control-workers with an optimal reliability degree. The values of the area under the ROC curves show that the inventory has a high discriminating capacity. 展开更多
关键词 BULLYING At workPLACE ORGANIZATIONAL Stress work-RELATED Psychiatric Disturbances work Psychosocial Environment Risk Assessment
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Tapping Advantages and Expanding International and Domestic Networks for Further Integrating Jiangxi with the Rest of the World——Thriving Foreign Related Work in Jiangxi Province
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作者 Zhang Xuejun Ai Hong 《International Understanding》 2013年第3期54-58,共5页
"…enable Jiangxi to become the example of ecological civilization and pacesetter of building beautiful China,and realize the dream of a prosperous,harmonious and beautiful Jiangxi through our earnest efforts.&qu... "…enable Jiangxi to become the example of ecological civilization and pacesetter of building beautiful China,and realize the dream of a prosperous,harmonious and beautiful Jiangxi through our earnest efforts."Recent years have witnessed vigorous efforts made by the Provincial Foreign Affairs and Overseas Chinese 展开更多
关键词 Thriving Foreign Related work in Jiangxi Province Tapping Advantages and Expanding International and Domestic Networks for Further Integrating Jiangxi with the Rest of the World
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Beyond Stitches: Analysis of Disease Burden in a Bangladeshi RMG Factory
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作者 Mariam Zaman Tayeb Ahmmed +3 位作者 Nabila Binte Hossain S. M. Raysul Haque Ariful Islam Joarder Kamran ul Baset 《Health》 2024年第7期688-702,共15页
Introduction: Bangladesh has experienced remarkable growth in RMG over the past 25 years. With the knitwear industry providing more than 4 million direct jobs, providing better occupational health and safety of worker... Introduction: Bangladesh has experienced remarkable growth in RMG over the past 25 years. With the knitwear industry providing more than 4 million direct jobs, providing better occupational health and safety of workers remains a challenge. Aim of the study: The aim of the study was to analyze the disease burden of a RMG factory, and to highlight occupational health risks. Methods: A cross-sectional study design was employed for this analysis. A 17-month data entry (January 2020 - May 2021) was gathered from the factory in-house clinic. The socio-demographic and clinical diagnosis entries of 8421 entries were analyzed. Result: The population of the factory workers is 5370, where 40% (2148) are female workers and 60% (3222) are male workers. The mean age of respondents is 30 years, with a SD of ±7 years. Among the chief complaints, the most common was vomiting (14%;2262) fever (14%;2247), runny nose (11%;1842), cough (9%;1465), and loose motion (8%;1364). In the diagnosis categories, gastrointestinal diseases were more predominantly diagnosed (35%;2978), followed by viral fever (21%;1772), neurological diseases (16.5%;1389) and musculoskeletal disorders (9%;768). The average cost of medicine for each respondent is BDT 36. The factory covered costs of all medication for 99% (8380) of respondents. Only 0.5% (37) was referred to a tertiary hospital for further evaluation. Conclusion: Garments workers suffer mostly from long-term occupational health hazards. Factory owners and policy makers can contribute in various ways to improving primary healthcare options for workers. 展开更多
关键词 RMG Disease Burden work Related Disease Communicable Disease Occupational Safety
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Implementation of a Return to Work Strategy in Germany—Are There Changes in Work-Related Rehabilitation Measures and Employment Status in Chronic Conditions?
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作者 Cornelia Gerdau-Heitmann Monika Schwarze 《Open Journal of Therapy and Rehabilitation》 2016年第1期55-66,共12页
Objectives: Aging workforces with increasing numbers of chronic conditions require health initiatives with greater workplace focus. A regional pension insurance introduced a Return To Work (RTW) strategy for insurants... Objectives: Aging workforces with increasing numbers of chronic conditions require health initiatives with greater workplace focus. A regional pension insurance introduced a Return To Work (RTW) strategy for insurants with chronic conditions. The objective was to identify the degree of implementation of work related measures in medical rehabilitation and the extent of RTW outcomes. Methods: 5883 insurants were considered. Severe Restriction of Work Ability (SRWA), Work-related Medical Rehabilitation (WMR), and Case Management (CM) were examined for 2008 and 2012. An Index of Employment status (IoE) was used in a logistic regression. Results: Utilization of WMR raised from 12.3% in 2008 to 66.1% in 2012. The proportion of insurants with SRWA and WMR grew from 8% up to 40.1%. In 2008, 14.7% of insurants with SRWA received WMR;in 2012, it grew to 76.6%. On the other hand, in 2012 26% got WMR without SRWA and 12.2% had SRWA and got no WMR. CM was not conducted in 2008 but reached 20.2% in 2012. Across all indications, WMR resulted in positive RTW as measured by IoE: OR = 0.75 (KI-95%: 0.67 - 0.86). Conclusion: WMR was successfully implemented according to the German guideline. There is a need to optimize the linkage between SRWA and WMR and CM to provide need-based care. 展开更多
关键词 Chronic Conditions Return to work (RTW) work-Related Medical Rehabilitation (WMR) Case Management (CM) Severe Restrictions of work Ability (SRWA)
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Experimental Study on Entropy Features in Machining Vibrations of A Thin-Walled Tubular Workpiece
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作者 Kaibo Lu Xin Wang +2 位作者 Xun Chen Xinyu Pang Fengshou Gu 《Journal of Dynamics, Monitoring and Diagnostics》 2023年第1期61-68,共8页
In machining processes,chatter vibrations are always regarded as one of the major limitations for production quality and efficiency.Accurate and timely monitoring of chatter is helpful to maintain stable machining ope... In machining processes,chatter vibrations are always regarded as one of the major limitations for production quality and efficiency.Accurate and timely monitoring of chatter is helpful to maintain stable machining operations.At present,most chatter monitoring methods are based on the energy level at specified chatter frequencies or frequency bands.However,the spectral features of chatter could change during machining operations due to complexity and time-varying dynamics of the physical machining process.The purpose of this paper is to investigate the time-varying chatter features in turning of thin-walled tubular workpieces from the perspective of entropy.The airborne acoustics was selected as the source of information for machining condition monitoring.First,corresponding to the distinguishing surface topographies relevant to machining conditions,the features of the sound signal emitted during turning of the thin-walled cylindrical workpieces were extracted using the spectral analysis and wavelet packet transform,respectively.It was shown that the dominant vibration frequency as well as the energy distribution could shift with the transition of the machining status.After that,two relative entropy indicators based on the spectrum and the wavelet packet energy were constructed to identify chattering events in turning of the thin-walled tubes.The experimental results demonstrate that the proposed indicators could accurately reflect the transition of machining conditions with high sensitivity and robustness in comparison with the traditional FFT-based methods.The achievement of this study lays the foundations of the online chatter monitoring and control technique for turning of the thin-walled tubular workpieces. 展开更多
关键词 MACHINING chatter relative entropy thin-walled work pieces
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Localization Algorithm of Indoor Wi-Fi Access Points Based on Signal Strength Relative Relationship and Region Division 被引量:4
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作者 Wenyan Liu Xiangyang Luo +3 位作者 Yimin Liu Jianqiang Liu Minghao Liu Yun Q.Shi 《Computers, Materials & Continua》 SCIE EI 2018年第4期71-93,共23页
Precise localization techniques for indoor Wi-Fi access points(APs)have important application in the security inspection.However,due to the interference of environment factors such as multipath propagation and NLOS(No... Precise localization techniques for indoor Wi-Fi access points(APs)have important application in the security inspection.However,due to the interference of environment factors such as multipath propagation and NLOS(Non-Line-of-Sight),the existing methods for localization indoor Wi-Fi access points based on RSS ranging tend to have lower accuracy as the RSS(Received Signal Strength)is difficult to accurately measure.Therefore,the localization algorithm of indoor Wi-Fi access points based on the signal strength relative relationship and region division is proposed in this paper.The algorithm hierarchically divide the room where the target Wi-Fi AP is located,on the region division line,a modified signal collection device is used to measure RSS in two directions of each reference point.All RSS values are compared and the region where the RSS value has the relative largest signal strength is located as next candidate region.The location coordinate of the target Wi-Fi AP is obtained when the localization region of the target Wi-Fi AP is successively approximated until the candidate region is smaller than the accuracy threshold.There are 360 experiments carried out in this paper with 8 types of Wi-Fi APs including fixed APs and portable APs.The experimental results show that the average localization error of the proposed localization algorithm is 0.30 meters,and the minimum localization error is 0.16 meters,which is significantly higher than the localization accuracy of the existing typical indoor Wi-Fi access point localization methods. 展开更多
关键词 Wi-Fi access points indoor localization RSS signal strength relative relationship region division.
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ON SOME BASIC PRINCIPLES IN DYNAMIC THEORY OF ELASTIC MATERIALS WITH VOIDS 被引量:2
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作者 罗恩 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1993年第2期142-148,共7页
According to the basic idea of dual-complementarity,in a simple and unified way proposed by the author,some basic principles in dynamic theory of elastic materials with voids can be established sys- tematically.In thi... According to the basic idea of dual-complementarity,in a simple and unified way proposed by the author,some basic principles in dynamic theory of elastic materials with voids can be established sys- tematically.In this paper, an important integral relation in terms of convolutions is given,which can be con- sidered as the generalized principle of virtual work in mechanics.Based on this relation,it is possible not on- ly to obtain the principle of virtual work and the reciprocal theorem in dynamic theory of elastic materials with voids,but also to derive systematically the complementary functionals for the eight-field,six-field, four-field and two-field simplified Gurtin-type variational principles.Furthermore,with this approach,the in- trinsic relationship among various principles can be explained clearly. 展开更多
关键词 dynamic theory of elastic materials with voids principle of virtual work reciprocal theorem variational principle complementary relation
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ELASTIC-PLASTIC CONSTITUTIVE MODELS BASED ON THE MULTIPLICATION PROCESSES OF DEFORMED GRAINS
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作者 何宗彦 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1996年第3期257-268,共12页
According to the characteristics of micro-deformation of polycrystalline metal,the author divides grains intothree kinds and proposes a new conceplion of deformed grains.multiplication,from which some explicit elastic... According to the characteristics of micro-deformation of polycrystalline metal,the author divides grains intothree kinds and proposes a new conceplion of deformed grains.multiplication,from which some explicit elastic-Plastic constitutive equations can be deduced and some experimental results can be explained quantitativelv,It shows that the macro-yield,rate-correlativity work hardening and other phenomena are all closely related to the kinetic process of grains deformation. 展开更多
关键词 POLYCRYSTAL elastic-plastic deformation constitutive relation yield work hardening DISLOCATION
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ANNUAL WORKING REPORT OF CAS DIVISION OF BIOLOGY (Abridged) 被引量:1
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作者 Zou Chenglu CAS member and director of the CAS Division of Biology. 《Bulletin of the Chinese Academy of Sciences》 1997年第1期20-24,共5页
Ⅰ. A REVIEW OF OUR WORK FROM 1994 TO 1996 1. Entrusted by the CPC central committee and the State Council, our Division completed its counseling assignments to the "Decision on Speeding up China’s S&T Progr... Ⅰ. A REVIEW OF OUR WORK FROM 1994 TO 1996 1. Entrusted by the CPC central committee and the State Council, our Division completed its counseling assignments to the "Decision on Speeding up China’s S&T Progress Jointly Decreed by the Party’s Central Committee and the State Council," "An Outlined Report on the Train of Thought for Devising S&T Development in the National Ninth Five-year Plan & the Long-term Scheme for National S&T Development up to 2010," "The Ninth Five-year Plan and Long-term Scheme for National S&T(?) 展开更多
关键词 CAS ANNUAL workING REPORT of CAS division of BIOLOGY Abridged
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