A variability taxonomy to support automation decision-making for manufacturing processes

Abstract

Although many manual operations have been replaced by automation in the manufacturing domain in various industries, skilled operators still carry out critical manual tasks such as final assembly. The business case for automation in these areas is difficult to justify due to increased complexity and costs arising out of process variabilities associated with those tasks. The lack of understanding of process variability in automation design means that industrial automation often does not realize the full benefits at the first attempt, resulting in the need to spend additional resource and time, to fully realize the potential. This article describes a taxonomy of variability when considering the automation of manufacturing processes. Three industrial case studies were analyzed to develop the proposed taxonomy. The results obtained from the taxonomy are discussed with a further case study to demonstrate its value in supporting automation decision-making.     

Correcting the practice styles of errant physicians

In spite of their reluctance, physicians cannot continue to avoid judgments on the practice styles of their professional colleagues. Both tort law and an increasingly aggressive buyer and consumer community demand attention to problem physicians. Physician executives can play a leadership role in helping physicians understand their role in the peer review process.     

Recognition of Emotions in Gait Patterns by Means of Artificial Neural Nets

This paper describes an application of emotion recognition in human gait by means of kinetic and kinematic data using artificial neural nets. Two experiments were undertaken, one attempting to identify participants’ emotional states from gait patterns, and the second analyzing effects on gait patterns of listening to music while walking. In the first experiment gait was analyzed as participants attempted to simulate four distinct emotional states (normal, happy, sad, angry). In the second experiment, participants were asked to listen to different types of music (excitatory, calming, no music) before and during gait analysis. Derived data were fed into different types of artificial neural nets. Results showed not only a clear distinction between individuals, but also revealed clear indications of emotion recognition in nets.     

Resource Tangibility and Patterns of Interaction in a Publicly Funded Health and Human Services Network

This article examines a publicly funded mental health servicesnetwork, focusing on the patterns of interaction in five resource-basedsubnetworks. We argue that the structure of network relationshipscan be explained by the nature of the resources that are atthe source of the interaction. Depending on whether a particularresource is tangible or tacit, subnetwork structures will differin predictable ways. We found that the pattern of interactionsamong network organizations in resource-based subnetworks appearsto be dependent on the organizations controlling these resources(the Network Administrative Organization versus network members)as well as the nature of the resource (tangible versus knowledgebased). Our research extends theory on network interactionsas well as having implications for network practice.     

再造乐高

表面看来，乐高似乎并没有遇到任何麻烦。作为全球第四大玩具制造商，乐高在2004年的玩具销售总额高达1315亿美元，产品线几乎涵盖了所有领域，包括从小孩子们玩的积木到大孩子们玩的组装机器人。新产品源源不绝，在乐高每年的销售总额当中，有四分之三是由新产品所创造的。     

Child and family social work: organizational context and identity

In the years since 1948, child and family social work has, to differing degrees at different times, sought to identify itself with a national centrally directed service, with the local service organization, with its clientele and with an independent source of professional regulation. Changes in the organizational context in which the work has been carried out over this period have affected the prospects for the development of a secure identity. The effects of the following are considered: national structures, particularly in relation to children's departments between 1948 and 1971; the corporate local authority; the managerial function in social services departments; social care; specialization; the detailed scrutiny of practice; care management and the Children Act 1989.     

A Deliberative Method for Ranking Risks (II): Evaluation of Validity and Agreement among Risk Managers

A deliberative method for ranking risks was evaluated in a study involving 218 risk managers. Both holistic and multiattribute procedures were used to assess individual and group rankings of health and safety risks facing students at a fictitious middle school. Consistency between the rankings that emerged from these two procedures was reasonably high for individuals and for groups, suggesting that these procedures capture an underlying construct of riskiness. Participants reported high levels of satisfaction with their groups' decision-making processes and the resulting rankings, and these reports were corroborated by regression analyses. Risk rankings were similar across individuals and groups, even though individuals and groups did not always agree on the relative importance of risk attributes. Lower consistency between the risk rankings from the holistic and multiattribute procedures and lower agreement among individuals and groups regarding these rankings were observed for a set of high-variance risks. Nonetheless, the generally high levels of consistency, satisfaction, and agreement suggest that this deliberative method is capable of producing risk rankings that can serve as informative inputs to public risk-management decision making.     

Adaptive independence samplers

Markov chain Monte Carlo (MCMC) is an important computational technique for generating samples from non-standard probability distributions. A major challenge in the design of practical MCMC samplers is to achieve efficient convergence and mixing properties. One way to accelerate convergence and mixing is to adapt the proposal distribution in light of previously sampled points, thus increasing the probability of acceptance. In this paper, we propose two new adaptive MCMC algorithms based on the Independent Metropolis–Hastings algorithm. In the first, we adjust the proposal to minimize an estimate of the cross-entropy between the target and proposal distributions, using the experience of pre-runs. This approach provides a general technique for deriving natural adaptive formulae. The second approach uses multiple parallel chains, and involves updating chains individually, then updating a proposal density by fitting a Bayesian model to the population. An important feature of this approach is that adapting the proposal does not change the limiting distributions of the chains. Consequently, the adaptive phase of the sampler can be continued indefinitely. We include results of numerical experiments indicating that the new algorithms compete well with traditional Metropolis–Hastings algorithms. We also demonstrate the method for a realistic problem arising in Comparative Genomics.     

Ecological Risks of Diazinon from Agricultural Use in the Sacramento – San Joaquin River Basins, California

A probabilistic risk assessment was conducted to evaluate the likelihood and ecological significance of potential toxic effects of diazinon in the Sacramento-San Joaquin system. Diazinon, an organophosphorus insecticide, is used in the Sacramento-San Joaquin River Basin as a dormant spray on almonds and other tree crops, as well as for other agricultural and urban applications. Diazinon and other pesticides have been detected in the Sacramento and San Joaquin Rivers and their tributaries. Diazinon exposure was characterized based on monitoring programs conducted in 1991-94. Diazinon effects were characterized using laboratory toxicity data for 63 species, supplemented by results from field mesocosm and microcosm studies. The assessment addressed the possibility that reductions in invertebrate populations could lead to impacts on species of fish that feed on those invertebrates. The risk assessment concluded that fish in these rivers are not at risk from the direct effects of diazinon in the water. Invertebrates are at greater risk, especially in agriculturally dominated streams and drainage channels during January and February. Cladocerans--including Daphnia magna and Ceriodaphnia dubia, two common bioassay species--are especially sensitive to diazinon and other organophosphates and are likely to be subject to acute toxic effects in some locations at some times. Any ecological damage that may occur, however, is brief and limited to cladocerans. None of the fish species of concern depend on cladocerans as critical components of their diet. Invertebrates that are not affected by observed concentrations of diazinon (copepods, mysids, amphipods, rotifers, and insects) are preferred foods for fish in the Sacramento-San Joaquin system.