应急管理部多层级视频会议系统跨网段转发技术

介绍应急管理部视频会议系统接入地震系统的基本情况,结合地震应急视频会议系统应用现状,分析多层级跨网视频会议系统的架构特点,着重分析跨网段"背靠背"转发优化技术方案在视频会议系统融合中的实现与应用,以期为类似的应用场景提供参考。     

全国地震应急视频会议系统建设及应用

地震应急体系随着国家"十五"重大项目"中国数字地震观测网络"项目的验收初步确立,应急指挥系统建设逐步完善,视频会议系统在地震应急响应中发挥了日益重要的作用。本文简要介绍了视频会议系统的基本组成和关键技术,详细阐述了全国地震应急视频会议系统的网络拓扑结构、主要功能以及在地震应急中的实际应用情况。本文对将来地震应急视频会议应用模式的流程化、规范化有一定实际意义。     

山西省地震应急视频会议系统建设与应用

文章主要对山西省地震视频会议系统的建设、组网、运行维护做简要介绍,并对该系统在应急协同、政务会议、震情会商、远程培训等方面的具体应用进行阐述,进一步明确视频会议系统在地震应急中的作用。     

全国地震应急视频会议系统组会模式

介绍点点结构、网状结构和树结构视频会议组会模式技术特点,及在地震应急中存在的问题;结合地震应急视频会议系统发展需求及在不同应用状态(单点连接、多省连接、市县连接、现场连接及应急演练)下的实际应用效果,探讨星形结构和两级树结构在地震应急视频会议中的技术优势,指出现有地震应急视频会议系统平台技术瓶颈及可能解决途径.     

云南地震应急视频会议组网模式研究

本文在分析国内地震系统应急视频会议建设、组网和应用的基础上，根据云南地震应急视频会议部署现状，提出日常、演练和应急3种视频会议组网模式，并在2018年8月13日、14日2次通海5.0级地震和2018年9月8日墨江5.9级地震应急视频会议组网中进行检验，检验结果表明，该系统符合云南省实际情况。     

云视频会议在地震应急视频会议系统中的融合应用研究

地震应急视频会议系统是应急指挥技术系统的重要组成部分,是开展地震应急处置的重要支撑手段.北京地震应急视频会议系统由传统的硬件视频会议组成,经过多年的运转和使用,硬件设备问题和局限性凸显.云视频会议作为一种新兴视频会议技术,在调配灵活性、兼容性和资源利用率方面有明显优势.文章围绕云视频会议和硬件视频会议系统的融合应用展开研究,实现了远程培训、远程参会、地震应急现场通讯演练、会议监控等多功能应用场景.实践表明,该融合应用是提高地震应急视频会议系统能力的有效手段.     

视频会议系统在地震应急中的应用

目前视频会议成为网络应用的热点,本文通过论述其组成及工作原理,结合辽宁省地震应急指挥需求组建视频会议系统,并通过实际应用来阐述视频会议系统在辽宁省地震应急指挥中发挥的作用。     

视频会议系统在地震应急中的应用

为实现将地震现场的图像与声音实时地传输到四川省地震局地震应急指挥中心，采用了一套点对点的视频会议系统。地震现场配备一台卫星终端，并在电脑上加装了视频采集压缩卡和Picture Tel公司的视频会议系统卡，即组成一套简易便携可靠性高的现场图像传输系统。卫星终端提供64kbps的高速卫星通道，使用MPEG1压缩格式，配合数字摄像机将现场的震情、灾情与社情传输到地震应急指挥中心。为政府做出切实有效的应急决策提供了依据。     

基于ADC方法的云南地震现场指挥部视频会议集成系统应用效能评估

根据ADC方法的基本原理,从可用性、可信性、能力三个维度建立效能指标,构建了地震应急技术系统的应用效能评估模型。以云南地震现场指挥部视频会议集成系统为评估对象,对该系统进行了效能评估。评估结果表明,该系统的效能较好。对于地震应急技术系统包含的不同的软硬件平台,可根据评估对象的逻辑结构和功能,建立效能评估指标,并采用此方法进行评估。     

九寨沟7.0级、精河6.6级地震应急视频会议系统应用及问题探讨

总结了九寨沟7.0级、精河6.6级地震应急不同时期的指挥部视频会议应用特点,分析了出现的画面声音卡顿、控制失步等问题。结合测试实验结果,探讨了影响视频会议质量的原因。为进一步加强震后应急视频会议保障服务能力,提出了建立视频会议服务质量标准、规范视频会议系统建设标准和丰富震后通讯手段等建议。     

SCIENCE CHINA Earth Sciences SUBJECT INDEX TO VOLUME 57(2014)

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A Monte Carlo study of rainfall forecasting with a stochastic model

A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.     

Distribution of throughfall and stemflow in multi‐strata agroforestry,perennial monoculture,fallow and primary forest in central Amazonia,Brazil

The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi‐strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open‐area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for palmito, respectively, 0·5% in the cupuaçu monoculture and 3·1% in the fallow. With more than 20% of the open‐area rainfall, the highest stemflow contributions to the water input into the soil were measured in the palm monocultures and in the fallow. Copyright © 1999 John Wiley & Sons, Ltd.     

Anthropogenic Eutrophication and Red Tide Outbreak in Lacustrine Systems of the Kashmir Himalaya

Red tide, a recurrent phenomenon has become conspicuous in several Kashmir lake ecosystems since 1991. The responsible organism (Euglena pedunculata), a rare flagellate rediscovered in the Kashmir Himalaya (Khan 1993) caused first and unprecedented red tide outbreak, constituting a maximum of 96% of resident numerical phytoplankton density in Dal Lake. At present, conflicting hypotheses exist on the generation of causal assemblage(s) imparting redness to waters: Jeeji Bai (1991) linked its origin to acid precipitation – a fallout of burning oil‐fields during the Gulf War – whilst Khan (1993) holds local factor(s) responsible. Field/experimental studies support the latter contention that the influx of untreated sewage, in unison with warm temperatures, high levels of PhAR, iron and interruption to hydrological flow‐pattern together with absence/or reduction in grazing activity created conducive environmental milieu for red tide outbreak. Dal Lake “red tide” drifted the bloom‐inoculum to other waters, including Lake Wular, where additional ecological niches were carved out, threatening the aesthetic value and biological diversity of Kashmir lakes. Ecological monitoring indicates frequent seasonal red tide occurrence in Dal Lake (including summer‐autumn event of 1998) which testifies its unabated eutrophication status. Further studies are needed on ecological adaptability and biogeographic distribution of this rare and unique red tide‐causing flagellate.