The BIA has now 15 years of experience with the certification of complex electronic systems for safety-related applications in the machinery sector. Using the example of machining centres, this presentation will show the systematic procedure for verifying and validating control systems using Application Specific Integrated Circuits (ASICs) and microcomputers for safety functions.One section will describe the control structure of machining centres with control systems using “ integrated safety.” A diverse redundant architecture combined with crossmonitoring and forced dynamisation is explained. In the main section the steps of the systematic certification procedure are explained showing some results of the certification of drilling machines. Specification reviews, design reviews with test case specification, statistical analysis, and walk-throughs are the analytical measures in the testing process. Systematic tests based on the test case specification, Electro Magnetic Interference (EMI) and environmental testing, and site acceptance tests on the machines are the testing measures for validation.A complex software driven system is always undergoing modification. Most of the changes are not safety-relevant but this has to be proven. A systematic procedure for certifying software modifications is presented in the last section of the paper. 相似文献
Abstract: Among the major agricultural crops in the southeastern United States, cotton ( Gossypium hirsutum L.) generally provides the least suitable habitat for most early successional songbirds. Newer cropping approaches, such as use of conservation tillage and stripcover cropping, offer hope for improving the ecological value of cotton fields. We examined the effects of clover stripcover cropping with conservation tillage versus conventionally grown cotton with either conventional or conservation tillage on avian and arthropod species composition and field use in east-central Georgia. Stripcover fields had higher bird densities and biomass and higher relative abundance of arthropods than both conservation tillage and conventional fields. During migration and breeding periods, total bird densities on stripcover fields were 2–6 times and 7–20 times greater than on conservation and conventional fields, respectively. Abundance and biomass for epigeal arthropods were also greatest on stripcover fields during much of the breeding season. Although the clover treatment attracted the highest avian and arthropod densities, conservation fields still provided more wildlife and agronomic benefits than conventional management. Our findings suggest that both conservation tillage and stripcropping systems will improve conditions for birds in cotton, with stripcropped fields providing superior habitat. The reduction of inputs possible with the clover system could allow farmers to lower costs associated with conventional cotton production by $282–317/ha. This reduction of input, coupled with similar or possibly increased yield over conventional systems makes stripcover cropping not only a good choice for reducing negative impacts on wildlife and surrounding ecosystems, but also an economically desirable one. 相似文献
ABSTRACT: The Pacific Northwest (PNW) regional assessment is an integrated examination of the consequences of natural climate variability and projected future climate change for the natural and human systems of the region. The assessment currently focuses on four sectors: hydrology/water resources, forests and forestry, aquatic ecosystems, and coastal activities. The assessment begins by identifying and elucidating the natural patterns of climate vanability in the PNW on interannual to decadal timescales. The pathways through which these climate variations are manifested and the resultant impacts on the natural and human systems of the region are investigated. Knowledge of these pathways allows an analysis of the potential impacts of future climate change, as defined by IPCC climate change scenarios. In this paper, we examine the sensitivity, adaptability and vulnerability of hydrology and water resources to climate variability and change. We focus on the Columbia River Basin, which covers approximately 75 percent of the PNW and is the basis for the dominant water resources system of the PNW. The water resources system of the Columbia River is sensitive to climate variability, especially with respect to drought. Management inertia and the lack of a centralized authority coordinating all uses of the resource impede adaptability to drought and optimization of water distribution. Climate change projections suggest exacerbated conditions of conflict between users as a result of low summertime streamfiow conditions. An understanding of the patterns and consequences of regional climate variability is crucial to developing an adequate response to future changes in climate. 相似文献
Objective: Traffic crashes are one of the leading causes of fatalities among Chinese children. Booster cushion usage in China is low, and there are no studies showing how a population with limited experience handles booster cushions during buckling up. The purpose of this study was to evaluate the handling of and explore the attitudes toward booster cushions among children, parents, and grandparents in Shanghai.
Methods: An observational study including a convenience sample of 254 children aged 4–12 years was conducted in 2 passenger cars at a shopping center in Shanghai. Parents, grandparents, or the children themselves buckled up the child on 2 types of booster cushions, a 2-stage integrated booster cushion (IBC) and an aftermarket booster cushion (BC). The test participants were observed during buckling up, first without and then with instructions. The test leaders conducted structured interviews.
Results: Ninety-eight percent of the uninstructed participants failed to buckle up without identified misuse on the aftermarket booster cushion and 31% of those uninstructed on the integrated booster cushion. The majority of misuse was severe, including placing the belt behind the arm and the lap belt routing above the guiding loops. Instruction reduced misuse to 58% (BC) and 12% (IBC), respectively, and, in particular, severe misuse. Some misuse was related to limited knowledge of how to buckle up on the booster cushion, and some misuse was intentional in order to reduce discomfort.
The participants, both children and adults, reported that they preferred the IBC due to good comfort and convenience. Safety was reported as the main reason for adults using booster cushions in general, whereas children reported comfort as the most important motivation.
Conclusions: Education is needed to ensure frequent and correct use of booster cushions in China and to raise safety awareness among children and adults. Furthermore, it is important that the booster cushions offer intuitively correct usage to a population with limited experience of booster cushions.
This is the first study published on the handling of and attitude toward booster cushions after child restraints laws were introduced in Shanghai 2014. 相似文献
Objective: The purpose of this article is to describe a public school–based educational intervention (EI) designed to increase knowledge, improve attitudes, and change practices related to road safety.
Methods: We used a mixed-methods evaluation of a road traffic safety baseline diagnosis conducted in 4 public schools, 2 primary and 2 secondary. Research was organized into 4 phases: (1) diagnosis, (2) EI design, (3) implementation, and (4) evaluation. We used convenience sampling (n = 219 students) across schools and applied a pre-/posttest design based on quantitative and qualitative data. The former related to surveys on road safety experiences, knowledge, attitudes, and practice and the latter to observation checklists, community mapping, ethnography, and focus groups. To compare pre–post scores, we used multilevel mixed-effect ordinal logistic regressions. We developed data matrices, field notes, and systematized community mapping. We also transcribed focus group discussions, generated categories, and carried out thematic analysis.
Results: Ethnography indicated poor sidewalk conditions, no helmet or seat belt use, overcrowded public transportation, and no traffic lights or proper signals. Pedestrians did not use sidewalks and crossed streets unsafely. Subsequent to the intervention, however, the study population showed significant changes in their knowledge, practices, and attitudes. They identified road traffic incidents (RTIs) as the first cause of death among children and youth, and most understood that the solution to the problem was incumbent upon each and every individual. They also displayed increased perceptions of danger in practices such as traveling on overcrowded public transportation, failing to wear seat belts in cars and helmets on motorcycles, crossing the street while using mobile phones or playing with friends, and riding with drunk drivers. Changes varied according to gender, and students reported being able to carry out safe practices only when they were in control of the situation; for instance, as pedestrians.
Conclusions: Because safe practices depend not only on children and youth but on the adults and social environment surrounding them, it is essential to engage parents, teachers, and decision makers in efforts to reduce RTIs. This will improve the establishment of commitments to impact social reality through consistent changes and mobilize greater resources for creating more secure communities in matters of road safety. 相似文献