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1.

There is increasing concern regarding the impacts of recreational four-wheel driving (4WDing) on sandy beach environments. The ghost crab Ocypode cordimanus is a widely distributed Australian species that utilizes beaches and dunes for constructing burrows and for foraging. Comparisons of ghost crab abundances (using burrow counts) in areas “open” and “closed” to recreational 4WDing were conducted on exposed sandy beaches on North Stradbroke Island, off the coast of southeast Queensland. Beaches where recreational 4WD activity is present had significantly lower ghost crab abundances than beaches where it is absent. The most plausible reason for this difference in abundance is that ghost crabs are highly vulnerable to being crushed by beach traffic when feeding on the beach at night. To mitigate the impacts of recreational 4WDing on ghost crab population management intervention is needed. Possible changes to the management of recreational 4WD activity include the setting aside of areas free of recreational 4WD activity for the conservation of biodiversity, or a prohibition on driving on the beaches between dusk and dawn. There is also a need for a consistent and transparent approach in Queensland for quantifying and monitoring 4WD activity in sandy beach environments.  相似文献   

2.
针对贝叶斯网络方法在处理大规模复杂系统上的优点,结合当前船用锅炉的安全性定量分析特点,提出将贝叶斯网络方法应用于船用锅炉的安全性分析。通过探讨贝叶斯网络及故障树分析方法原理,尝试将贝叶斯网络与故障树分析方法结合起来,主要突出贝叶斯网络方法可以实现数据的自动更新及由后验信息到先验信息的反向推理能力。最后将该方法应用于船用锅炉的安全性定量分析中,通过更新观测部件故障状态实现了整个系统的自动更新,并自动查找出最大概率事件,证实该方法提高了安全性分析效率,使实际操作更加准确、快捷,极大地的降低了事故带来的风险。  相似文献   

3.
为模拟海洋温跃层环境,检验所设计的水下热滑翔机在温跃层中的水动力性能,根据相似理论分析了温度梯度为0.2 ℃/m及水深10 m以下的海洋温跃层模拟水池的各项特征:缩尺比、水池主尺度、温度场和动力相似数。采用数值计算和理论计算方法,预测了设计水池中的待试模型与实体水下热滑翔机的阻力,并对二者进行比较,验证了所设计的水池模拟的水动力效果。以传感器阵列测量水池的温度梯度,验证了温度场相似的设计目标。通过研究和试验,验证了海洋温跃层模拟水池的可行性和可靠性。研究表明:用于水下热滑翔机水动力及相变性能研究的海洋温跃层模拟水池,其水流温度梯度需为实际温跃层温度梯度的缩尺比的平方倍;模拟海洋温跃层的室内水池通过选取合理的几何尺寸,可以抑制阻塞效应、浅水效应及池壁效应的不良影响。  相似文献   

4.
The Gulf of California hosts astounding biodiversity that supports numerous economic activities in the region. These activities, and emerging threats, are placing pressure on the region's ecosystems. Government and civil society are working to address threats through several conservation and management mechanisms. Nevertheless, the use and incorporation of scientific information—a key component for creating effective and durable management—is still deficient. This article presents the concept of science integration and discusses the findings of a study that assesses the regional landscape, existing institutional arrangements, and capacity for using science to inform policy and management decisions. It also explores the current use of science within fisheries policy and management and the capacity of the National Network of Information and Research of Fisheries and Aquaculture (RENIIPA) and the State Fisheries and Aquaculture Councils, two mechanisms in the region. Finally, it shares lessons learned and offers recommendations on how the region can strengthen science-based decision-making. Results indicate that while there are some actors in the Gulf of California producing relevant science, there is varying capacity of intermediary groups connecting producers with users of science, or mechanisms in place to ensure that science is being utilized in decision-making processes. Moreover, despite having a well-developed landscape of producers and intermediaries and mechanisms in place for fisheries management in the region, effective science integration is not occurring.  相似文献   

5.
本文首先指出我国旅客运输系统结构的变化趋势和沿海客运系统内部的变化趋势,并把岛屿和陆岛客运作为整个沿海客运的一个子系统来考虑。通过对客运量生成和运输方式选择的分析,建立了沿海客运系统客运量发展模型,提出客运量主要决定于人均社会总产值、区域人口数和系统的综合服务水平,并预测了我国2000年沿海客运系统客运量和周转量。据此对发展沿海客运系统的资金作了估算。同时,论述了车/客渡船将是未来我国客船的发展方向,并初步研究了海峡两岸直接通航后两岸客运的发展规模和我国沿海旅游业的发展前景。  相似文献   

6.
孟凡亮  周徐昌  刘洪  谢勇 《舰船电子工程》2012,32(9):116-117,120
该文讨论了混合验前分布时水中兵器的鉴定方案问题。在可靠性鉴定试验中,Bayes方法可以大量节省试验次数,但是过度依赖验前信息,当新产品有改进时会造成鉴定结果的冒进,而且对于双方风险的判断往往出现分歧。该文通过引入继承因子,在验前信息中加入均匀分布,减弱了对验前信息的过度依赖,更合理的考虑了产品的变化对评定结果的影响。再次基础上该文重点分析了混合验前分布时的使用方和生产方风险。计算结果表明此方法可以在节约试验样本的条件下兼顾了评定方案的稳健性。  相似文献   

7.
Site selection is a key factor in any aquaculture operation, affecting both success and sustainability. Moreover, it can solve conflicts between different coastal activities, making a rational use of the coastal space. Geographical information systems (GIS) have become of increased significance for environmental planning and assessment mainly because of the need to compare a great number of spatially related data, and because it can be used to couple these spatial data with their attributes and overlay them. This study used GIS and related technology to build a spatial database using those criteria which were considered to have any influence in integrating marine fish-cage culture within the tourism industry in Tenerife. Criteria were grouped in three submodels (distance to beaches, nautical sports, and viewshed), which were combined to generate a final output showing the most suitable areas for cage culture development in coexistence with tourism. Most areas of the coastline of Tenerife were identified as being suitable (56%) or very suitable (46%), suggesting that marine cage aquaculture could be developed on the island in coexistence with the well-established tourism industry.  相似文献   

8.
为了解决战场环境下的声呐系统损伤评估及修复(SSBDAR)问题,本文研究了战场损伤评估及修复模型。针对舰艇声呐系统战场损伤评估的因果推理特性,建立了基于贝叶斯网络的战场损伤评估模型,提出了基于贝叶斯网络的评估流程,给出了基于贝叶斯网络的评估决断算法。该模型利用贝叶斯网络对各评估修复节点进行分析,能够解决损伤信息不确定性,而且充分利用舰艇声呐系统各节点的损伤信息,提高了模型评估及修复效率,是解决舰艇声呐系统战场损伤评估及修复问题的一个有效途径。  相似文献   

9.
提出一种基于负荷停电信息的舰船电力系统故障定位方法,该方法结合目前船用电力系统的技术状态,通过显控台提供的电气设备间的拓扑关系,利用舰员或用电设备终端上报的停电信息判断故障发生的区域。针对实际操作中可能出现的"停电拒报"、"误报"等情况,将树形辐射供电特点与贝叶斯公式相结合,提出"4个有关集合"的概念,并基于此概念计算各候选区域发生故障的概率,最后选择概率最大者作为最终的故障判定区域。  相似文献   

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