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排序方式: 共有2168条查询结果,搜索用时 218 毫秒
51.
Qin Liu Nancy R. Cook Anna Bergstrm Chung-Cheng Hsieh 《Computational statistics & data analysis》2009,53(12):4157-4167
To estimate a summarized dose–response relation across different exposure levels from epidemiologic data, meta-analysis often needs to take into account heterogeneity across studies beyond the variation associated with fixed effects. We extended a generalized-least-squares method and a multivariate maximum likelihood method to estimate the summarized nonlinear dose–response relation taking into account random effects. These methods are readily suited to fitting and testing models with covariates and curvilinear dose–response relations. 相似文献
52.
This article provides an analysis of the evolution of the division of labour in participatory ergonomics (PE) programmes in two worksites. The analysis is based on interviews and field observations in the worksites. In both settings there was meaningful participation by both worker and management members of ergonomic change teams (ECTs) in the hazard assessment and solution identification stages, but as the teams moved to the implementation stage, worker representatives were marginalised and the participatory nature of the programmes was severely curtailed. The removal of workers from the process was the outcome of the interplay among the type of activities pursued in the implementation stage, the skills and knowledge required to carry out those activities, and workers' limited influence in the organisational hierarchies. Findings highlight the salience of the social context in which participatory programmes are located and the importance of examining participatory programmes as they evolve over time. STATEMENT OF RELEVANCE: This article contributes to a growing literature on the process and implementation of PE programmes. The article's focus on social and organisational factors that affect the division of labour and attention to the evolution of involvement over time extend current understandings of participation in ergonomics programmes. 相似文献
53.
Effects of chemical protective equipment on team process performance in small unit rescue operations
In the event of a nuclear, biological, or chemical terrorist attack against civilians, both military and civilian emergency response teams must be able to respond and operate efficiently while wearing protective equipment. Chemical protective equipment protects the user by providing a barrier between the individual and hazardous environment. Unfortunately, the same equipment that is designed to support the user can potentially cause heat stress, reduced task efficiency, and reduced range-of-motion. Targeted Acceptable Responses to Generated Events of Tasks (TARGETS), an event-based team performance measurement methodology was used to investigate the effects of Mission Oriented Protective Posture (MOPP) on the behavioral processes underlying team performance during simulated rescue tasks. In addition, this study determined which team processes were related to team performance outcomes. Results of six primary analyses indicated that team process performance was not degraded by MOPP 4 on any rescue task and that the team processes critical for successful task performance are task-dependent. This article discusses the implications of these results with respect to the study design and the limitations of using an event-based team performance measurement methodology. 相似文献
54.
Unified use case statecharts: case studies 总被引:1,自引:0,他引:1
Davor Svetinovic Daniel M. Berry Nancy A. Day Michael W. Godfrey 《Requirements Engineering》2007,12(4):245-264
This paper presents the results of case studies evaluating a method of unifying use cases (UCs) to derive a unified statechart
model of the behavior of the domain of a proposed computer-based system. An evaluation of the unification method, the obtained
statechart model of the domain, the method’s and model’s feedback on the UCs themselves, and how the method is used in requirements
engineering practice was carried out by examining 58 software requirements specifications produced by 189 upper-year undergraduate
and graduate students. The results of these studies independently confirm some of the benefits of building a unified SC mentioned
in the works of Glinz; Whittle and Schumann; and Harel, Kugler, and Pnueli.
相似文献
Davor SvetinovicEmail: |
55.
Theberge N Granzow K Cole D Laing A;Ergonomic Intervention Evaluation Research Group 《Applied ergonomics》2006,37(2):239-248
In participatory ergonomic (PE) interventions, "how" effective participation by workplace parties can be achieved remains unclear. We conducted a case study of the dynamics of an ergonomic change team (ECT) process in a medium-sized (175 employees) automotive foam manufacturing plant. We present analyses of observer field notes and post-intervention interviews from which key elements on the dynamics of the "how" emerged: (1) impacts of facilitators' involvement and interests; (2) tensions in delimiting the scope of ECT activities; issues around (3) managing meetings and (4) realizing labour and management participation; and (5) workplace ECT members' difficulties in juggling other job commitments and facing production pressures. We highlight the ongoing negotiated nature of responses to these challenges by labour, management and ergonomic facilitator members of the ECT. We argue for greater examination of the social dynamics of PE processes to identify additional ways of fostering participation in ergonomic project implementation. 相似文献
56.
Vangelis Gazis Nancy Alonistioti Nikos Houssos Maria Koutsopoulou Stefan Gessler Juergen Quittek 《Journal of Network and Systems Management》2006,14(2):221-241
Mobile communications beyond 3G will integrate different (but complementary) access technologies into a common platform to deliver value-added services and multimedia content in an optimum way. However, the numerous possible configurations of mobile networks complicated the dynamic deployment of mobile applications. Therefore, research is intensely seeking a service provisioning framework that is technology-independent, supports multiple wireless network technologies, and can interwork high-level service management tasks to network management operations. This paper presents an open value chain paradigm, a model for downloadable applications and a mediating platform for service provisioning in beyond 3G mobile settings. Furthermore, we introduce mechanisms that support a coupled interaction between service deployment and network configuration operations, focusing on the dynamic provisioning of QoS state to data path devices according to the requirements of dynamically downloadable mobile value-added services (VAS).
相似文献
Vangelis GazisEmail: |
57.
This paper studies the problem of detecting multiplechanges at unknown times in the mean level of elision in thetrimeter sequences of the Orestes, a play written by theAncient Greek dramatist Euripides (485–406 B.C.). Change-detection statistics proposed by MacNeill (1978) and Jandhayala and MacNeill(1991) are adopted for this purpose. Analysis of the trimetersequences yields several points of change. A general explanation fortheir occurrence appears to be that Euripides varies his use ofelision according to the emotional content of his text, i.e., heseems to change the form to support the content and, thus, seems touse elision frequency as a dramatic instrument. 相似文献
58.
Buc NL 《Food and drug law journal》1993,48(2):223-226
59.
As the fish community changed in the Beaver Archipelago (northern Lake Michigan), so has the diet of breeding Double-crested Cormorants (Phalacrocorax auritus). In 2000, the energetically dense alewife (Alosa pseudoharengus) dominated the diet, but more recently, the relatively low quality round goby (Neogobius melanostomus) has become the most common prey item. Additionally, cormorant control measures have been underway in the archipelago. This study investigated decreases in cormorant chick numbers and changes in chick bioenergetics in response to this change in diet, as well as the influence of control efforts, and compared these results to an earlier study. Two colonies, one actively controlled the other only controlled following completion of this study, were investigated to determine changes in colony size throughout the breeding season, document chick diet, measure chick growth, and determine chick survivorship to fledging. The bioenergetics model estimated that in 2010, chicks consumed a greater biomass of prey to reach fledging due to the change in diet, but lower biomass overall due to fewer chicks in the system. Control efforts in combination with the change in diet reduced chick numbers. Overall, the impact of cormorant chicks on available fish biomass has declined in recent years due to control efforts. However, the birds have the potential to consume a greater biomass of round goby in the absence of control. The impact of cormorants on fisheries resources is complicated by the abundance and effects of non-native species. 相似文献
60.
Diporeia, formerly the dominant benthic macroinvertebrate in the Great Lakes, remains a keystone species in Lake Superior. Little is known, however, about fine scale amphipod distributions, especially as influenced by the production, transport and transformation of energy resources. Here, we document the distribution and abundance of Diporeia along 19 transects around the lake's perimeter. Regions of elevated density, averaging 958 ± 408 Diporeia/m2 (mean ± S.D.) were observed along all transects, typically within slope habitat (depth of 30–125 m). Waters shoreward (shelf habitat, < 30 m) and lakeward (profundal habitat, > 125 m) of these regions supported significantly lower densities, averaging 239 ± 178/m2 and 106 ± 59/m2, respectively. Amphipods within regions of elevated density, termed here the Ring of Fire, account for two-thirds of the lakewide population while occupying only one-quarter of the benthic habitat. The Ring of Fire, observed lakewide as a band averaging 14.2 ± 9.4 km in width, is characterized as a region of transitional sediment deposition with gentle slope, proximate to nearshore locations of elevated primary production. Within the Ring of Fire exceptionally high densities are found in the south central region, where the Keweenaw Current and slope bathymetries serve to funnel production from adjoining regions of high production. Density measurements for the 173 stations sampled here are used to estimate lakewide Diporeia standing stock (22.5–37.7 trillion individuals, 4.4–7.4 Gg dry weight, 2.1–3.5 Gg C), individual and biomass density (274–460/m2, 0.05–0.09 g DW/m2, 0.03–0.04 gC/m2) and areal (0.02–0.03 g C/m2/yr) and total (1.6–2.6 Gg C/yr) production. 相似文献