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391.
基于云类样本的红外-可见光二维灰度空间投影,采用模糊聚类方法调整优化云类样本特征区域,消除采样误差。针对常规模糊C均值聚类(FCM)方法在处理上述问题时表现出的局限性,提出用样本特征均值替代FCM中随机初始中心的改进办法,既避免了常规FCM方法对初始中心敏感的缺陷,又可纠正其聚类结果对云类样本特征结构的歪曲。改进后的聚类结果既消除了采样误差,又保持了云类样本的基本特征属性,基于该判据的分类结果可较为准确地分辨出陆地、水体、低云、中云、卷云和积雨云,分割判别效果符合客观实际。  相似文献   
392.
针对防空导弹武器系统的暴露特征,采用层次分析法,建立了防空导弹武器系统伪装能力多层次综合评价指标体系和综合评价模型,采用模糊聚类分析法对数据进行处理,得出各评价对象的综合评价结果。最后通过算例,验证了该模型的有效性。  相似文献   
393.
As environmental problems and pressures on natural resources escalate, awareness building and efforts to protect natural areas have also became a major goal to ensure sustainability. Ecotourism is one of the major activities to protect natural and cultural resources, while also providing economic benefits to both local people and government. Successful ecotourism planning is a function of establishing sound goals and criteria. In this paper, we have presented the example of Igneada, Turkey, as a case to elaborate this point. Igneada a coastal town, located on the north-west Black Sea region of Turkey, was declared a national park in 2007. The park is well known for its longos forests (flooded), lagoons, endemic and endangered species, and wildlife. However, currently, unsustainable economic activities, overgrazing, and urbanization cause threats to its sensitive ecosystems. Promoting ecotourism is a sustainable approach to balance economic, social, and environmental aspects in the development of Igneada.

The aim of this study is to define a set of ecotourism criteria and propose an ecotourism vision for Igneada. The methodology in this research involves field observations and a strengths, weaknesses, opportunities and threats analysis with an Analytical Hierarchy Process. A survey study is conducted with both local people and experts to define a framework to generate a priority ranking for ecotourism-planning decision. The research generated 5 main criteria and 14 subcriteria, among which ‘Proposal of Igneada in Turkey’s 2023 Tourism Strategy Plan’ was the highest ranked opportunity for ecotourism planning and development in the town.  相似文献   

394.
A novel water control technology that combines the features of a reticular blind drainage system and a vertical hierarchical drainage system is developed and applied in the Yanziyan Sanitary Landfill, which is located at an area (Loudi City, Hunan Province, China) with high rainfall and high groundwater level. The reticular blind drain system, which was installed on the bottom and side walls of the landfill site, can conveniently guide the flow of groundwater out of the site while preventing a disorganized flow of groundwater. The vertical hierarchical drainage system was installed to separate rainfall water and leachate in the landfill site, thus efficiently reducing the pressure of leachate treatment. The whole drainage system plays a key role in foundation stabilization by seepage control and separation and in the instant drainage of rainfall water. The leachate reduction efficiency of the drainage technology was calculated in terms of leachate production before (336519 m3) and after (29664 m3) technology application. Over 90% of leachate derived from rainfall water and groundwater inflow was avoided upon installation of the vertical hierarchical drainage and reticular blind drainage systems. The technology can thus be popularized and applied for water control in landfills located in areas with high rainfall and high groundwater level. The proposed technology can be used to alleviate the pressure of leachate treatment and to reduce the risk of instability.  相似文献   
395.
保持和提高森林土壤肥力质量是实现森林健康的基础。研究不同林型下土壤肥力质量对森林可持续经营具有重要意义。以东北过伐林区金仓林场中的落叶松Lartx gmelinii人工纯林、云杉Picea asperatax紫椴Tilia amurensis天然混交林、紫椴×白桦Betula platyphylla天然混交林、五角槭Acer monox白桦×落叶松天然混交林、五角槭×白桦×紫椴天然混交林、白桦×落叶松天然混交林和五角械×紫椴×青杨Populus pseudo-simonii天然混交林为研究对象,分析和比较了不同林分下的土壤物理和化学性质,并采用主成分分析与聚类分析相结合的方法评价了其土壤肥力质量。结果表明:①林分类型对土壤理化性质影响显著;随土壤深度增加,土壤密度和土壤pH值增大,而土壤含水量、物理性粘粒含量和养分质量分数减少,但其在不同林分下的变化程度不同;②土壤因子之间关系密切,物理性粘粒含量与含水量、全氮、速效钾质量分数呈极显著正相关,而与土壤密度和pH值呈显著负相关;土壤养分质量分数之间具有不同程度的显著正相关关系;③采用主成分分析法对不同林分下0~60cm的土壤肥力质量进行了评价,土壤肥力质量表现为天然混交林高于落叶松人工纯林;采伐降低了土壤的肥力质量;在落叶松人工纯林中,随着林龄的增加,土壤的肥力质量下降。通过对土壤肥力质量综合指标值的聚类分析,将研究区土壤肥力质量分为优、良、中、差4个等级,肥力质量属于中等以上(优、良、中等)的林地所占研究样地的比例为66.7%,研究区森林土壤肥力质量属于中等水平。建议在经营过伐林时,注意调整林分结构和树种组成,控制采伐强度,同时进行长期定位观测和比较,以改善林分整体的肥力状况。本研究结果为该地区林业可持续经营提供直接依据,也为东北地区森林土壤肥力质量评价提供参考。  相似文献   
396.
Sharks and other large predators are scarce on most coral reefs, but studies of their historical ecology provide qualitative evidence that predators were once numerous in these ecosystems. Quantifying density of sharks in the absence of humans (baseline) is, however, hindered by a paucity of pertinent time-series data. Recently researchers have used underwater visual surveys, primarily of limited spatial extent or nonstandard design, to infer negative associations between reef shark abundance and human populations. We analyzed data from 1607 towed-diver surveys (>1 ha transects surveyed by observers towed behind a boat) conducted at 46 reefs in the central-western Pacific Ocean, reefs that included some of the world's most pristine coral reefs. Estimates of shark density from towed-diver surveys were substantially lower (<10%) than published estimates from surveys along small transects (<0.02 ha), which is not consistent with inverted biomass pyramids (predator biomass greater than prey biomass) reported by other researchers for pristine reefs. We examined the relation between the density of reef sharks observed in towed-diver surveys and human population in models that accounted for the influence of oceanic primary productivity, sea surface temperature, reef area, and reef physical complexity. We used these models to estimate the density of sharks in the absence of humans. Densities of gray reef sharks (Carcharhinus amblyrhynchos), whitetip reef sharks (Triaenodon obesus), and the group "all reef sharks" increased substantially as human population decreased and as primary productivity and minimum sea surface temperature (or reef area, which was highly correlated with temperature) increased. Simulated baseline densities of reef sharks under the absence of humans were 1.1-2.4/ha for the main Hawaiian Islands, 1.2-2.4/ha for inhabited islands of American Samoa, and 0.9-2.1/ha for inhabited islands in the Mariana Archipelago, which suggests that density of reef sharks has declined to 3-10% of baseline levels in these areas.  相似文献   
397.
利用2017年10月~2018年8月的PM10、PM2.5、PM1质量浓度数据以及NCEP全球再分析气象资料,分析乌鲁木齐市区和南郊山区颗粒物浓度变化特征,结合HYSPLIT后向轨迹模型、潜在源贡献因子分析(PSCF)以及浓度权重轨迹分析(CWT)分析市区颗粒物潜在源区.研究结果表明:①市区PM2.5的超标天数为26d,南郊山区无PM2.5超标,市区PM10的超标天数是南郊山区的3.5倍,市区日均值及月均值质量浓度是南郊山区的2~7倍,市区呈现冬高夏低的季节特征,南郊山区春季最高;②乌鲁木齐市区PM10日变化存在3个峰值,PM2.5、PM1为双峰型分布,南郊山区均呈双峰分布;并存在季节性周末效应;③长短两支聚类气流轨迹对乌鲁木齐市区颗粒物浓度影响较大,春夏气流来自中亚,秋冬来源于北疆周边地区;④颗粒物潜在源区分布季节特征显著,高值区主要为昌吉、巴州、吐鲁番等周边地区,西北部中亚地区也是颗粒物重要来源区域之一.  相似文献   
398.
以降低公路隧道火灾风险为目的,结合国内外公路隧道火灾特点及危害,分析研究了公路隧道火灾事故的致因。采用解释结构模型(ISM)分析各原因之间的层次关系,建立了4级递阶结构关系。结果显示:第一层致因为隧道中运行车辆的起火和隧道自身结构火灾起火;第二层为隧道中司乘人员引起的不同车辆火灾和隧道运营管理存在危险性;第三层为隧道中车辆的危险性预防和对隧道的安全检查;最深层原因集中于管理因素,安全教育、安全意识的形成和对安全监管的投入力度上,隧道运营管理者的行为措施。交通管理部门可以通过对公路隧道火灾起火原因分析出发,找出增强隧道安全性的有效途径。  相似文献   
399.
运用ISM法建立了矿工安全心理影响因素的三层递阶结构模型,分析矿工安全心理影响因素,明晰各因素之间的层次递阶关系。结果显示,表层直接影响因素为个体心态、生理疲劳和工作应激;中层间接影响因素主要涉及个性气质、作业环境、组织公平等因素;深层根本影响因素为安全教育培训、生产组织管理及生产工艺技术这三项因素。煤矿企业可从影响矿工安全心理的根本因素出发,寻找增强矿工安全心理的有效途径。研究结果为煤矿安全管理、矿工不安全心理预防提供了一定的参考。  相似文献   
400.
绿色建筑是指在建筑的全寿命周期内,最大限度地节约资源,保护环境和减少污染,为人们提供健康、适用和高效的使用空间,与自然和谐共生。根据绿色建筑的特点,确立绿色建筑评价指标体系,并运用管理理论中的层次分析法(AHP)和模糊综合评价方法(Fuzzy),提出了人工神经网络(ANN)评价模型。评估结果表明,该评价体系用于绿色建筑等级综合评价是快速、有效的。  相似文献   
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