Assessing the landscape context and conversion risk of protected areas using satellite data products

Since the establishment of the first national park (Yellowstone National Park in 1872) and the first wildlife refuge (Pelican Island in 1903), dramatic changes have occurred in both ecological and cultural landscapes across the U.S. The ability of these protected areas to maintain current levels of biodiversity depend, at least in part, on the integrity of the surrounding landscape. Our objective was to quantify and compare the extent and pattern of natural land cover, risk of conversion, and relationships with demographic and economic variables in counties near National Park Service units and U.S. Fish and Wildlife Service refuges with those counties distant from either type of protected area in the coterminous United States. Our results indicate that landscapes in counties within 10 km of both parks and refuges and those within 10 km of just parks were more natural, more intact, and more protected than those in counties within 10 km of just refuges and counties greater than 10 km from either protected area system. However, they also had greater human population density and change in population, indicating potential conversion risk since the percent of landscape protected averaged < 5% in both groups and human population dynamics are primary drivers of change in many landscapes. Conversion outweighed protection by at least two times (Conservation Risk Index > 2) in 76% of counties near both parks and refuges, 81% of counties near just parks, 91% of counties near just refuges, and 93% of distant counties. Thirteen percent of counties in the coterminous U.S. had moderate to high amounts of natural land cover (> 60%), low protection (< 20%), and the greatest change in population (> 20%). Although these areas are not the most critically endangered, they represent the greatest conservation opportunity, need, and urgency. Our approach is based on national level metrics that are simple, general, informative, and can be understood by broad audiences and by policy makers and managers to assess the health of lands surrounding parks and refuges. Regular monitoring of these metrics with satellite data products in counties surrounding protected areas provides a consistent, national level assessment of management opportunities and potentially adverse changes on adjacent lands.     

一种融合社交信任的矩阵分解推荐算法

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将网络管理系统(NMS)与入侵检测系统(IDS)结合,提出了一种分布式入侵检测系统:简单入侵检测系统(Sim-pleIntrusionDetectionSystem简称SIDS),它引入分层过滤、分布处理、自治代理的思想。系统由收集器、分析器等多级实体组成,实体之间采用SNMPV3进行通信。文章还详细讨论了如何用SNMPV3实现SNMP代理与管理者之间高效、安全、可靠的通信问题。     

基于AT90S8515和USB接口数据采集系统

USB总线具有高速传输、热拔插、即插即用等特点,已经得到越来越广泛的应用。文中以AT90S8515单片机为核心,采用TLC08388位串行A/D转换器,基于USB100模块设计了一个串行数据采集系统。文中给出了该系统的硬件原理图及主要源程序。     

车-地通信场景的一种混合建模方法研究

为了更好地建立高速列控系统分布式整体形式化描述,采用Agent理论和层次着色Petri网混合建模方法对中国列车控制系统车-地通信场景进行了研究。将车-地通信场景抽象为MAS,给出了场景中车-地主体Agent的内部推理过程和形式化定义,采用CPN Tools工具建立了层次化结构HCPN模型,使车-地通信过程、MAS整体行为以及车-地主体内部推理流程可视化。通过对模型状态空间报告的分析确保了模型的正确性,通过对模型进行多次模拟仿真,分析了该场景中不同通信故障率情况下非周期消息的重发间隔对控车实时性能的影响,验证了模型的可行性。     

安徽省立医院信息系统设计与实现

介绍安徽省立医院信息系统的设计与实现,提出一种关于开发信息系统的设计方法和步骤,为开发复杂的信息系统提供新的思路。     

企业海量数据库的优化

当前大多数企业应用软件都需要数据库支持, 而且数据库的规模在不断扩大, 尤其用到数据仓库技术的商业智能化支持系统。面对大数据量, 企业级应用的性能愈来愈依赖数据库的性能。对数据库性能要素进行全面的描述和分析, 以便对数据库的选择、应用和基于数据库的二次开发提供工程参考。