Multiple Workers Research Articles

Sampling Strategies for Occupational Exposure Assessment under Generalized Linear Model

Occupational exposure assessment is a major task in industrial hygiene studies. Although statistical analyses for magnitudes and variations of exposures to various types of working populations based on existing data sets are extensive, relatively few discussions on study designs appear in the literature, especially for sample size determination and number of repeated measurements. In this paper, we propose a general framework of sampling strategies on sample size requirement together with the number of repeated measurements using the mixed-effects generalized linear model (GLM). As illustrative examples, we discuss sampling strategies separately under the log-normal assumption for hypotheses testing on (i) mean exposure differences of multiple worker groups and (ii) presence of a long-term exposure trend. Given a specified alternative hypothesis, the desired significance level and statistical power, the number of repeated measurements, within-worker and between-worker variances, and a correlation structure, we have derived and tabulated an explicit sample size requirement of the two hypothetical cases under log-normal distribution assumption. On the basis of the tabulated outcomes, the sample size requirement is much more dominant than the number of repeated measurements for a group exposure comparison. Thus, in this case, recruiting more workers with fewer repeated measurements may be more economical than the opposite approach. For testing the presence of a long-term exposure trend, the sample size required decreases substantially with the number of repeated measurements. Also, equally spaced sampling times would be optimal because the effect of between-worker variance is algebraically cancelled out in sample size calculations.

Special Issue: Advanced Strategies in Grid Environments—Models and Techniques for Scheduling and Programming

Special Issue: Advanced Strategies in Grid Environments—Models and Techniques for Scheduling and Programming

Amphibole forensics: Using the composition of amphiboles to determine their source, the Libby, Montana, example

As part of a larger on-going research project, we found amphiboles in soils in Libby, Montana, that were derived from both the former vermiculite mine near Libby and other sources. SEM-EDS spectra of the soil amphiboles from these locations are used to ascertain if the amphiboles came from the vermiculite deposit near Libby, Montana, or some other source. This distinction is possible because amphiboles known to originate from the vermiculite deposit all contain Na and K that can be observed in the EDS spectra. We make this statement with confidence because multiple workers have performed EPMA characterization on over 40 amphiboles collected from the deposit and all are found to contain measureable amounts of Na and K. In this brief communication, we show examples from four locations that contain amphiboles consistent in composition and others that have inconsistent composition when compared to reference amphiboles collected from the vermiculite deposit. Also, we demonstrate the presence of amphiboles consistent in composition with amphiboles known to originate from the deposit in sediment that pre-date mining activity. A full-length publication is in preparation detailing the quantity, distribution, and composition of amphiboles in the Libby Valley, if they are consistent in composition with amphiboles known to originate from the deposit or not, and if they pre- or post-date mining operations.

Patient safety: A European Union priority

Every year in the 27 member states of the European Union, patients are harmed when receiving healthcare. Sometimes this is the fault of individual or multiple healthcare workers but more often than not organisational or system failures are to blame. The injuries and deaths from unsafe healthcare can never be completely eradicated. However, steps can be taken by policymakers and those responsible for the delivery of healthcare in all countries to reduce the human and economic burden of adverse events in all healthcare settings. Patient safety is an area of healthcare where economies of scales can be achieved through a European Community approach to tackling the problems. Share experiences, expertise, best practice and research findings can help member states to improve the safety of their health systems. This is why the European Commission put forward its patient safety proposal at the end of 2008.

Periodicity of Cycle Time in a U-Shaped Production Line with Heterogeneous Workers under Carousel Allocation

A U-shaped production line with multiple machines and multiple workers is considered under carousel allocation in which all workers take charge of all machines in the same order. Nakade and Ohno (2003) show that, when the processing, operation and walking times are constant, the overall cycle time, which is a time interval between successive outputs of finished goods, is the greatest value of the maximal sum of the processing and operation times among machines and the time required for a worker to operate and walk around the production line without waiting for processing divided by the number of workers. In this paper, it is considered that operation times at each machine may be different between workers. If processing time is short, it is expected that the overall cycle time will be equal to the time for a worker to operate and walk around the line divided by the number of workers. However, under some specified cases, the overall cycle time is longer than that of this time, and the overall cycle time changes periodically. From numerical examples, it is shown that the order of arrivals of workers at machine 1 affects the overall cycle time. We give some properties on the periodicity of cycle times and discuss about cycle times.

Long term results of radial tunnel release — the effect of co-existing tennis elbow, multiple compression syndromes and workers' compensation

Long term results of radial tunnel release — the effect of co-existing tennis elbow, multiple compression syndromes and workers' compensation

Speeding Up FPGA Placement via Partitioning and Multithreading

One of the current main challenges of the FPGA design flow is the long processing time of the placement and routing algorithms. In this paper, we propose a hybrid parallelization technique of the simulated annealing‐based placement algorithm of VPR developed in the work of Betz and Rose (1997). The proposed technique uses balanced region‐based partitioning and multithreading. In the first step of this approach placement subproblems are created by partitioning and then processed concurrently by multiple worker threads that are run on multiple cores of the same processor. Our main goal is to investigate the speedup that can be achieved with this simple approach compared to previous approaches that were based on distributed computing. The new hybrid parallel placement algorithm achieves an average speedup of 2.5× using four worker threads, while the total wire length and circuit delay after routing are minimally degraded.

Population genetic structure, worker reproduction and thelytokous parthenogenesis in the desert ant Cataglyphis sabulosa

In social Hymenoptera, within-colony relatedness is usually high due to the haplodiploid sex-determining system. However, factors such as the presence of multiple reproductive queens (polygyny), multiple queen matings (polyandry) or worker reproduction result in decreased relatedness among workers and the brood they rear, and consequently dilute their inclusive fitness benefits from helping. Here, we investigated population genetic structure, mating system, worker reproduction and parthenogenesis in the desert ant Cataglyphis sabulosa. Analysis of worker genotypes showed that colonies are headed by a single queen, mated with 1-5 males. The inbreeding coefficient within colonies and the levels of relatedness between the queens and their mates were positive, indicating that mating occurs between related individuals. Moreover, the mates of a queen are on average related and contribute equally to worker production. Our analyses also indicate that colonies are genetically differentiated and form a population exhibiting no isolation-by-distance pattern, consistent with the independent foundation of new colonies (that is, without the help of workers). Finally, both ovarian dissections and genetic data on the parentage of males show that workers do not reproduce in queenright colonies; however, they lay both haploid (arrhenotokous males) and diploid (thelytokous females) eggs in queenless colonies. In contrast to the congeneric species C. cursor, where new queens are produced by thelytokous parthenogenesis, female sexuals of C. sabulosa result from classical sexual reproduction.

A quantitative approach for scheduling activities to reduce set-up in multiple machine lines

The importance of ensuring short set-up times in manufacturing has been well-documented in the literature over the past years. However, this body of work largely addresses situations involving a single machine with no specific worker-related issues. In practice, there exist multiple machines or workstations that form a machine line, and that need set-up operations to be performed by multiple workers. The existing literature does not provide adequate methodologies for set-up reduction in such cases. This paper describes a quantitative modeling and algorithmic approach for scheduling activities or tasks in order to minimize the set-up time in such situations, also taking into account relevant secondary objectives such as balancing the workload amongst the workers, concentrating slack toward the end of the set-up process, and minimizing the movement costs of the workers performing the different set-up tasks. Three real-life examples are used to demonstrate the efficacy of the proposed approach.

Games of status and discriminatory contracts

Following recent empirical evidence which indicates the importance of rank for the determination of workers' wellbeing, this paper introduces status seeking preferences in the form of rank-dependent utility functions into a moral-hazard framework with one firm and multiple workers, but no correlation in production. We show that workers' concern for the rank of their wage in the firm's wage distribution induces the firm to offer discriminatory wage contracts when its aim is to induce all workers to expend effort.

Leaving Gateway Metropolitan Areas in the United States: Immigrants and the Housing Market

Immigration is no longer a phenomenon that is simply affecting gateway metropolitan areas in the United States. This analysis demonstrates that large numbers of immigrants are moving to other metropolitan areas and analyses the housing outcomes of households who currently live in the 14 largest emerging gateways. The findings suggest that those households that move from most gateway metropolitan areas have lower homeownership rates than do households that move from within the metropolitan area. Meanwhile, there is little evidence that immigrants do worse than native-born households that migrate within the US. The study also demonstrates that immigrants living in crowded conditions or having multiple workers in the household have higher homeownership rates than similar native-born households, and that younger immigrants are relatively more successful in attaining homeownership than are similar native-born residents.

Long term results of radial tunnel release – the effect of co-existing tennis elbow, multiple compression syndromes and workers' compensation

Surgical decompression of radial tunnel syndrome (RTS) remains controversial because the results are unpredictable. This study is a retrospective analysis of the long term outcomes of RTS release and a comparison of our findings with previous studies. Thirty-three extremities in 31 patients underwent decompression for radial tunnel syndrome between 1994 and 2003, of which 27 extremities in 25 patients were available for long term follow up after an average of 57 months (range 16 to 106 months). Outcomes were evaluated using the criteria of Ritts et al. (1987). For 16 patients (18 of 27 extremities), the outcome was rated as good (67%), for four patients (four extremities) as fair (15%), and for five patients (five extremities) as poor (18%). The outcome was better in patients with simple RTS (86% good results) compared with patients with additional nerve compression syndromes (57% good results), or patients with coexisting lateral epicondylitis (70% vs 43% good results), or patients who were receiving workers' compensation (73% vs 58% good results). One-third of patients still had moderate or severe disability which affected their ability to work, but 82% had relief of their pain. Surgical decompression is therefore beneficial for simple RTS, but may be less successful if there are co-existing additional nerve compression syndromes or lateral epicondylitis or if the patient is receiving workers'compensation.

Optimal allocation of heterogeneous workers in a U-shaped production line

In this paper, we deal with a U-shaped production line with multiple heterogeneous multi-function workers. Skills of workers are assumed to be different. We consider an optimization problem for finding an allocation of workers to the line that minimizes the overall cycle time under the minimum number of workers satisfying the demand. All of processing, operation and walking times are deterministic. We propose an algorithm for computing an optimal allocation of workers to machines.

The health centre as a location for care management

This paper examines the case for locating care management in health centres. Two related arguments are advanced. It is argued, firstly, that the close association between the health and social needs of dependent groups makes a multidisciplinary approach to community care essential. Secondly, it is suggested that the coordination of health and social care provision and the achievement of a seamless service would be achieved most readily in a setting which combined all of the main health and social care providers in one location. Other advantages include the potential contribution of general practitioners as case finders under the terms of the new GP contract and the fact that the introduction of care management to health centres would facilitate the mounting of experiments with different models of care management, particularly those involving a multiple worker approach.

Analysing the job characteristics model: new support from a cross-section of establishments

We evaluate the empirical relevance of the Job Characteristics Model of Hackman and Oldham in the modern organizational environment using unique, nationally representative data from a survey of British establishments. The data contain information on a large number of establishments and multiple workers within each establishment. The results generally support the Job Characteristics Model's predictions that task variety and worker autonomy are positively associated with labour productivity and product quality and that autonomy is positively associated with worker satisfaction. In contrast to previous studies, we find the results for task variety are stronger for the performance-related outcomes than for worker satisfaction. The theoretically predicted moderating effect of context satisfaction is largely unsupported in the data.

Management: Engineering Workflows Herald a New Era for Upstream Production

Over the last decade, a number of industries have improved their operations through workflow management—the management and improvement of data and activities through specific business, scientific, or engineering processes. Workflow management most commonly has been associated with business or back-office processes, where workflow-management systems have enabled improvements to productivity in tasks such as invoice processing, authority-for-expenditure management, and technical help-desk operations. In recent years, several industries have begun focusing on scientific and engineering workflows that differ in many ways from business workflows. A new generation of software tools is emerging to manage engineering work-flows in the upstream production domain. These tools will enable many of the promises of the "digital oil field" and are part of the answer to industry challenges such as the "graying" of the workforce, the increasing complexity of assets, and the need to optimize production operations. Types of Workflows Business workflows are the most common type employed by companies. The management of business workflows dates back to the 1970s, when workflows were purely paper based. As workflow management evolved to modern information technology systems, many industries re-engineered their business processes for increased efficiencies and lowered transaction costs for optimal performance. Workflow-management software became commonly used to implement improved workflows and integrate business processes that spanned multiple workers and multiple information technology systems. Scientific workflows gained wide acceptance in the field of bioinformatics in the early 2000s. Scientific and engineering workflows differ from business workflows. For example, where business workflows tend to deal with discrete transactions, engineering and scientific work-flows tend to deal with large data quantities, multiple data sources in multiple formats, and multiple interconnected tools. New software tools can be used to standardize engineering workflows by bringing together data from disparate systems and consolidating separate engineering capabilities within a single platform. New workflows are needed for production operations. The aging of the oilfield workforce means experience will be lost when older workers retire, and new workers will need to accomplish the same work with less learned knowledge. The automation of engineering processes allows fewer workers to manage the same assets and allows knowledge to be transferred in the form of documented workflows. The increasing complexity of operations requires the management of larger data sets for ongoing operations, more precise decision making, and the opportunity for optimization through controls. New engineering workflows are needed to meet all these challenges, and they must be implemented predictably across multiple assets. That will change engineering and operations in the upstream production arena. Engineering workflow systems can enable new capabilities for production surveillance through the use of automation and integration of modeling tools with multiple data sources, such as Merrick Systems' workflows.

Sham nepotism as a result of intrinsic differences in brood viability in ants

In animal societies, cooperation for the common wealth and latent conflicts due to the selfish interests of individuals are in delicate balance. In many ant species, colonies contain multiple breeders and workers interact with nestmates of varying degrees of relatedness. Therefore, workers could increase their inclusive fitness by preferentially caring for their closest relatives, yet evidence for nepotism in insect societies remains scarce and controversial. We experimentally demonstrate that workers of the ant Formica exsecta do not discriminate between highly related and unrelated brood, but that brood viability differs between queens. We further show that differences in brood viability are sufficient to explain a relatedness pattern that has previously been interpreted as evidence for nepotism. Hence, our findings support the view that nepotism remains elusive in social insects and emphasize the need for further controlled experiments.

Communicative and strategic action in interpreted consultations in primary health care: A Habermasian perspective

We report a qualitative study of accounts of interpreted consultations in UK primary care. The study sought to explore how three Habermasian tensions between (a) system and lifeworld, (b) communicative and strategic action, and (c) interpersonal and macropolitical spheres played out in the triadic consultation between clinician, interpreter and patient. In a total of 69 individual interviews and two focus groups, we collected narratives from service users (through interpreters or bilingual researchers), interpreters and doctors and other staff in general practice. We recorded, transcribed and analysed these, taking the story as the main unit of analysis. Our data suggest that the preconditions for communicative action are rarely met in the interpreted consultation. The interpreter's presence makes a dyadic interaction into a triad, adding considerable complexity to the social situation and generating operational and technical challenges. Lack of trust, intense pressure of time, mismatch of agendas (biomedical versus lifeworld), firm expectations of a specific outcome (e.g. referral, prescription) and profound power imbalances all promote strategic action (i.e. speech that seeks consciously or unconsciously to manipulate an outcome) rather than communicative action (i.e. sincere efforts to achieve understanding, and reach consensus) by all parties. In consultations interpreted by family members (an option traditionally seen as ‘second best’ by policy makers), the social situation is very different. Family members are generally trusted, share the lifeworld agenda, and shift the power balance in the patient's favour. The interpreter occupies multiple social roles, including translator, interpersonal mediator, system mediator, educator, advocate, and link worker. The essence of professionalism in interpreting is shifting judiciously between these potentially conflicting roles. We discuss the implications of our findings for communication with limited English speakers in healthcare consultations and for realizing contemporary policy goals such as concordance, shared decision-making, empowerment, and choice.

Chubb Corp.

Mergent's Dividend AchieversVolume 3, Issue 4 p. 57-57 U.S. Company Reports Chubb Corp.† First published: 10 October 2006 https://doi.org/10.1002/div.4700 † Contact: : John D. Finnegan — Chmn., Pres., C.E.O. Address: : 15 Mountain View Road, P.O. Box 1615, Warren, NJ 07061-1615 Web Site: : www.chubb.com AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Insurance (MIC: 8.2 SIC: 6331 NAIC: 524126) Chubb is a holding company with subsidiaries principally engaged in the property and casualty insurance business. Chubb Commercial Insurance offers a range of commercial customer insurance products, including coverage for multiple peril, casualty, worker,' compensation and property and marine. Chubb Specialty Insurance offers a variety of specialized professional liability products for privately and publicly owned companies, financial institutions, professional firms and healthcare organizations. Chubb Personal Insurance offers products for individuals with fine homes and possessions who require more coverage choices and higher limits than standard insurance policies. Volume3, Issue4Autumn (Fall) 2006Pages 57-57 RelatedInformation

Use of multiple opportunities for improving feeding practices in under-twos within child health programmes

In a community randomized trial, we aimed to promote exclusive breastfeeding and appropriate complementary feeding practices in under-twos to ascertain the feasibility of using available channels for nutrition counselling, their relative performance and the relationship between intensity of counselling and behaviour change. We also assessed whether using multiple opportunities to impart nutrition education adversely affected routine activities. We conducted a community randomized, controlled effectiveness trial in rural Haryana, India, with four intervention and four control communities. We trained health and nutrition workers in the intervention communities to counsel mothers at multiple contacts on breastfeeding exclusively for 6 months and on appropriate complementary feeding practices thereafter. The intervention was not just training health and nutrition workers in counselling but included community and health worker mobilization. In the intervention group, about 32% of caregivers were counselled by traditional birth attendants at birth. The most frequent sources of counselling from birth to 3 months were immunization sessions (45.1%) and home visits (32.1%), followed closely by weighing sessions (25.5%); from 7 to 12 months, home visits (42.6%) became more important than the other two. An increase in the number of channels through which caregivers were counselled was positively associated with exclusive breastfeeding prevalence at 3 months (p = 0.002), consumption of milk/cereal gruel or mix use at 9 months (p = 0.004) and 18 months (p = 0.003), undiluted milk at 9 months (p<0.0001) and 24 hour non-breast-milk energy intakes at 18 months (p = 0.023), after controlling for potential confounding factors. Intervention areas, compared with the control, had higher coverage for vitamin A (45% vs. 11.5%) and iron folic acid (45% vs. 0.4%) supplementation. Using multiple available opportunities and workers for counselling caregivers was feasible, resulted in high coverage and impact, and instead of disrupting ongoing services, resulted in their improvement.