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  • 基于MIN-MAX云重心推理的目标威胁评估方法

    将云推理技术引入信息融合领域,提出一种新的基于MIN-MAX云重心推理的威胁评估方法.按照实际应用背景下目标的特点,构建分层式威胁评估属性集合;定义云群、云族、云三层隶属关系,对各属性进行云模型转换,并根据各属性的云模型设计前件云发生器;依据专家经验,构建推理规则库,并设计MIN-MAX云重心推理算法,将归一化属性值输入相应的前件云发生器,生成属性云滴,通过由下而上地逐级推理,得到威胁度云滴;最后,将经过多次重复推理得到的威胁度云滴输入逆向云发生器,输出值作为最终的威胁程度.以联合防空作战为背景,仿真实现了空中目标的威胁评估,验证了该方法的有效性.
    张银燕,李弼程 - 系统仿真学报
    文章来源: 万方数据
  • 基于模糊综合评价的弹药效能评估方法

    本文结合模糊综合效能评估基本流程,对效能评估过程中的权重关系确定方法和评估模型确定方法进行了分析。并以某典型弹药为对象,并构建了其效能评价指标体系,运用模糊评估理论和层次分析方法对其进行了效能量化评估计算。研究结果表明,效能评估方法为弹药综合评价提供了一种有效的评价方法,对其他武器装备效能评价具有一定的借鉴意义。
    王保贵,战永红,王坚 - 测试技术学报
    文章来源: 万方数据
  • 濒危世界遗产威胁因素分析与中国世界遗产保护对策

    研究导致世界遗产"濒危"的威胁因素能够为我国世界遗产管理与保护提供重要借鉴.对全球濒危世界遗产威胁因素定量统计发现:武装冲突、管理不力、工程建设是世界文化遗产与世界自然遗产共同面临的三大威胁;世界文化遗产的主要濒危因素还包括城市发展压力、不合适的维修/重建等;世界自然遗产濒危因素则还包括非法偷猎、捕捞,以及林业采伐、农业种植、放牧等农林生产活动等.中国世界遗产面临的首要威胁因素是旅游发展压力,管理问题、城市发展压力、水利工程建设等也较为突出.提出中国世界遗产保护建议:明确遗产旅游价值取向,加强高峰期游客管理,控制旅游设施建设规模;提升管理水平与管理能力,探索世界遗产管理的新体系、新思路;妥善处理好城市发展对世界文化遗产的保护压力,积极预防极端自然灾害的破坏;严格控制世界自然遗产地内的道路建设、水利工程建设等.
    潘运伟,杨明,刘海龙 - 人文地理
    文章来源: 万方数据
  • 创新政策评估理论方法研究-基于公共政策评估逻辑框架的视角

    创新政策评估从本质上属于公共政策评估,文章从论述公共政策评估的要素出发,基于韦唐的“效果模式”下的“综合评估模式”,设计了公共政策评估的一般性理论方法框架.然后基于创新政策的理论基础,从创新政策概念、理念、创新过程、创新活动等方面总结了创新政策评估不同于一般公共政策评估的四个特点,在公共政策评估的理论方法框架的基础上建立了创新政策评估的理论框架.
    赵莉晓 - 科学学研究
    文章来源: 万方数据
  • Changes in Philornis infestation behavior threaten Darwin's finch survival

    The?conservation?behavior?framework?is?useful?to?identify?key?linkages?between?behavior?and?conservation?practice.?We?apply?this?framework?to?a?novel?host-parasite?system?on?the?Galapagos?Islands?and?ask?if?there?have?been?changes?in?parasite?oviposition?behavior?and?host?mortality?patterns?across?the?first?decade?(2004-2013)?of?its?known?association.?The?Dipteran?parasite?Philornis?downsi?was?first?discovered?in?Darwin's?finch?nests?in?1997?and?is?the?biggest?threat?to?the?survival?of?Galapagos?land?birds.?Host?mortality?has?increased?over?the?past?decade.?In?Dipterans,?pupation?and?pupae?size?are?determined?by?access?to?host?resources.?Here,?we?test?the?hypothesis?that?P?downsi?flies?are?laying?eggs?in?finch?nests?earlier?in?the?nestling?phase?to?maximize?larval?feeding?time?and?therefore?chance?of?pupation?success?before?host?death.?The?results?show?fewer?1st?instar?larvae?later?in?the?host?nesting?cycle?in?support?of?earlier?egg?laying?behavior?by?female?flies.?Between?2004?and?2013,?parasite?intensity?increased?from?-28?to?-48?parasites?per?nest,?host?mortality?increased?from?-50%?to?-90%,?and?host?age?at?death?decreased?from?-11?to?-5?days.?The?earlier?age?at?host?death?was?correlated?with?fewer?pupae?(from?-50%?to?-20%)?and?smaller?pupae?size?(-10%?decrease).?Changes?in?parasite?behavior?reveal?new?fitness?costs?to?both?the?parasite?and?Darwin's?finches.?These?findings?un-?derscore?the?need?for?urgent?conservation?action?to?save?Darwin's?finches?from?extinction?due?to?a?novel,?lethal?and?introduced?parasite?[Current?Zoology?60?(4):?542-550,?2014].
    Sonia KLEINDORFER,Katharina J. PETERS,Georgina CUSTANCE,Rachael Y. DUDANIEC,Jody A. O'CONNOR - 动物学报(英文版)
    文章来源: 万方数据
  • 目标威胁估计与传感器管理联合方法

    在面向目标跟踪的传感器管理问题中,以信息增量作为优化指标的方法未考虑到不同类型目标的影响程度.实际应用中,不同威胁程度的目标应给予不同程度的关注,从而分配不同的传感器资源,因此提出一种目标威胁估计与传感器管理联合方法.利用人工势场法计算各目标的威胁指数,根据目标的威胁指数及其信息增量来构造新的传感器管理目标函数,在概率假设密度滤波(PHDF)算法框架下,通过使得目标函数最大来实现传感器资源的优化分配.仿真结果表明,与仅考虑信息增量最大化的方法相比,该方法能更合理地分配传感器资源.
    岑明,孙敏,田甄 - 系统仿真学报
    文章来源: 万方数据
  • Compensatory foraging in Trinidadian guppies: Effects of acute and chronic predation threats

    Chris K. ELVIDGE,Indar RAMNARINE,Grant E. BROWN - 动物学报(英文版)
    文章来源: 万方数据
  • 鹰潭市结核病防治规划(2001-2010年)终期评估报告

    江西省鹰潭市面积3 554km2,辖2县(市)1区,共42个乡镇(街道),总人口111.57万,农村人口占49.5%,农村居民年人均收入5 508元.我市制订了《鹰潭市结核病防治规划(2001-2010年)》,自2003年起相继启动了现代结核病控制策略(DOTS
    应潜,聂志学,王坚 - 医学动物防制
    文章来源: 万方数据
  • 山西资源型地区循环经济指标体系评估研究

    评价山西资源型地区循环经济运行效率,建立具有代表性、可比性和动态性的循环经济指标体系评估机制,准确把握工作方向.通过评估,认为循环经济对节能减排做出了积极贡献,下一步工作重点是:加大资源综合利用力度,重点关注煤层气及瓦斯抽采回收率、城市污水再生利用率两项指标,进一步规模化纵深发展循环经济.
    陈新风,赵平利 - 经济问题
    文章来源: 万方数据
  • To forage or hide? Threat-sensitive foraging behaviour in wild, non-reproductive passerine birds

    Because antipredator behaviours are costly, the threat-sensitive predator avoidance hypothesis predicts that individual animals should express predator-avoidance behaviour proportionally to the perceived threat posed by the predator. Here, we experimentally tested this hypothesis by providing wild passerine birds supplemental food (on a raised feeding platform) at either 1 or 4 m from the edge of forest cover (potential refuge), in either the presence or absence of a nearby simulated predation threat (a sharp-shinned hawk Accipiter striatus model). Compared with the control treatment, we observed proportionally fewer bird visits to the food patch, and the birds took longer to re-emerge from forest refuge and return to feed at the food patch, after the hawk presentation than before it. The observed threat-sensitive latency-to-return response was stronger when the food patch was further away from the nearest refuge. Overall, our results are consistent with the predictions of the threat-sensitive predator avoidance hypothesis in that wild passerine birds (primarily black-capped chickadees Poecile atricapillus) exhibited more intense antipre- dator behavioural responses with increasing level of apparent threat. The birds were thus sensitive to their local perceived threat of predation and traded-off safety from predation (by refuging) and foraging gains in open habitat in a graded, threat-sensitive manner [Current Zoology 60 (6): 719-728, 2014].
    Shaun TURNEY,Jean-Guy J. GODIN - 动物学报(英文版)
    文章来源: 万方数据
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