经济系统的演化与政策作用

该文根据耗散结构的基本原理 ,将经济系统划分为平衡态、过渡态和自组织状态。并将政策因素看成是一种外部调控手段 ,分析了在经济系统的不同状态下 ,政策因素对改变系统的结构及变化趋势所起的不同作用     

BATHTUB-TYPE CURVES IN RELIABILITY AND BEYOND

Finding optimal, or at least good, maintenance and repair policies is crucial in reliability engineering. Likewise, describing life phases of human mortality is important when determining social policy or insurance premiums. In these tasks, one searches for distributions to fit data and then makes inferences about the population(s). In the present paper, we focus on bathtub‐type distributions and provide a view of certain problems, methods and solutions, and a few challenges, that can be encountered in reliability engineering, survival analysis, demography and actuarial science.     

Stochastic Modelling of Times to Temperature for Furnaces Supplying Titanium Blooms to a Rolling Mill at TIMET

In conjunction with TIMET at Waunarlwydd (Swansea, UK) a model has been developed that will optimise the scheduling of various blooms to their eight furnaces so as to minimise the time taken to roll these blooms into the finished mill products. This production scheduling model requires reliable data on times taken for the various furnaces that heat the slabs and blooms to reach the temperatures required for rolling. These times to temperature are stochastic in nature and this paper identifies the distributional form for these times using the generalised F distribution as a modelling framework. The times to temperature were found to be similarly distributed over all furnaces. The identified distributional forms were incorporated into the scheduling model to optimise a particular campaign that was run at TIMET Swansea. Amongst other conclusion it was found that, compared to the actual campaign, the model produced a schedule that reduced the makespan by some 35%.     

Imagined Memories

Most discussions of popular music on the Internet focus on the utopian potential of new file-sharing technologies, yet applications that reproduce existing inequalities also deserve attention. Webcasting is the streaming (transmission) of digital video to multiple recipients in cyberspace. Paul McCartney's Webcast from the Cavern was a landmark case. It was a digital package staged for reproduction, and yet it felt live; in this article I explore why and offer a two-part explanation. The first part is that "live'-ness is based on an increasingly false opposition to recording, but, because that opposition still remains, Little Big Gig could seem live by adopting some trappings associated with it. The second part is that Internet use is mediated by daily life and computer users brought their own desire to the Webcast, in particular desires to see a Beatle play in the Cavern. Webcasting is an unanticipated use of the Internet that is being used to support corporate interests. With its widespread publicity, Little Big Gig helped naturalize that process.     

A simulation study of a discrete-time multiserver retrial queue with finite population

In this paper, we deal with a discrete-time multiserver retrial queue with finite population. Firstly, we study the Markov chain at the epochs immediately after slot boundaries making emphasis on the computation of its steady-state distribution. Then, the main performance measures are investigated. Besides, we simulate the waiting time of a customer in the retrial group under three different queueing policies. Some numerical examples are given to illustrate the analysis.     

Asthma Patients' Activities and Air Pollution: A Semiparametric Censored Regression Analysis

Asthma patients' health status may be especially sensitive to some types of air pollution, but the evidence on this is mixed. We explore the effects of ground-level ozone on asthma patient's activities, breaking apart the usual aggregated category of leisure into indoor and outdoor activities, and differentiating those by whether the activities were active or inactive. Applying the semiparametric censored estimation method we demonstrate that even though the period over which activities were observed was relatively low in ozone levels, there is a significant impact of ozone on a few activities. The (non-ozone) economic and demographic variables in the model play significant roles in explaining the allocation of time among seven activities, suggesting the suitability of the approach for other household decision-making contexts.     

Disabled people's attitudes toward other impairment groups: a hierarchy of impairments

This article seeks to explore, through the literature, the notion that a hierarchy of impairment exists from the perspectives of both disabled and non-disabled people. The literature suggests that disabled people, like non-disabled people, do not always wish to be associated with other impairment groups for a variety of complex reasons, including competing for scarce allocations of funding/resources, sexual attraction, stigma, etc. The article concludes that further research is required in relation to disabled people's attitudes toward other disabled people, in general, and other impairment groups. Such research would expand our knowledge with respect to the degree to which disabled people view themselves as a homogenous in-group, as a set of separate impairment groups, or viewing impairment as only one facet of identity. These findings would help the disability movement to achieve greater inclusiveness amongst different impairments.     

Communication of risk: health hazards from mobile phones

Summary. Possible health hazards from mobile phones arise from the use of the phones themselves and via the base stations that relay signals. Except for an increase in traffic accidents induced by the use of mobile phones in cars the evidence for a health hazard is at most indirect, but it cannot be entirely dismissed; the phones have not been widely used for sufficiently long for direct epidemiological studies to have high sensitivity for detecting any induced incidence of cancer, for example. The background and evidence are briefly reviewed and the steps taken in the UK to make information widely available described.