煤尘爆炸性鉴定中瞬间火焰长度检测技术的研究

确定煤尘爆炸性质需要检测其燃烧瞬间的火焰长度,现有的大管状煤尘爆炸性鉴定系统以肉眼观察作为主要检测手段,存在测量精度差、重复性误差大以及人为干扰因素多等问题,提出将数字图像处理技术引入到煤尘爆炸性鉴定系统的方法即通过采用数字图像处理技术,对煤尘火焰图像进行预处理及图像分割与边缘检测后,得到最大火焰长度特征参数,并推导出煤尘爆炸的判断依据。     

基于彩色图像的林火图像火焰分割研究

结合实际林火图像的特点,提出了一种基于彩色图像分割策略的林火图像的火焰分割算法。该算法首先将图像转化为HSI彩色模型,然后根据各个分量的特点进行分割,并且进行了仿真实验,实验结果表明此算法能够很好地将火焰从复杂的背景中分割出来,克服了基于灰度图像分割不能准确分割烟雾和火焰的弊端,为今后对林火图像进一步分析提供了良好的基础。     

环境一号卫星CCD数据在生态环境监测和评价工作中的应用价值研究

基于环境一号卫星CCD传感器性能,从生态景观角度入手,针对江苏省地形地貌特征,开展了环境一号卫星CCD数据在生态环境监测和评价工作中的应用可行性研究,结果表明环境一号卫星CCD数据可以满足江苏省生态环境监测和评价工作需要,其时间分辨率和幅宽是开展生态监控和预警的重要优势。     

Comparing the Use of Indigenous Knowledge with Classification and Ordination Techniques for Assessing the Species Composition and Structure of Vegetation in a Tropical Forest

dentification of groups that are similar in their floristic composition and structure (habitat types) is essential for conservation and forest managers to allocate high priority areas and to designate areas for reserves, refuges, and other protected areas. In this study, the use of indigenous knowledge for the identification of habitat types in the field was compared against an ecological characterization of habitat types, including their species composition obtained by using classification and ordination techniques for a tropical landscape mosaic in a rural Mayan area of Quintana Roo, Mexico. Plant diversity data calculated from 141 sampled sites chosen randomly on a vegetation class’s thematic map obtained by multispectral satellite image classification were used for this propose. Results indicated high similarity in the categorization of vegetation types between the Mayan classification and those obtained by cluster and detrended correspondence analysis. This suggests that indigenous knowledge has a practical use and can be comparable to that obtained by using science-based methods. Finally, identification and mapping of vegetation classes (habitat types) using satellite image classification allowed us to discriminate significantly different species compositions, in such a way that they can provide a useful mechanism for interpolating diversity values over the entire landscape.     

Detecting Invasive Sericea Lespedeza (<Emphasis Type="Italic">Lespedeza cuneata</Emphasis>) in Mid-Missouri Pastureland Using Hyperspectral Imagery

Missouri ranks second in cow-calf numbers in the United States and its pastureland has experienced invasion of various plant species. As one of the invasive weeds, sericea lespedeza is becoming a serious threat to pasturelands in this state. The in-situ field survey in these vast pastures is time consuming and often impossible because of accessibility. Typical aerial survey is also difficult to detect sericea because the plant is of similar size and color as natural grass and, thus, cannot be effectively discriminated in broadband aerial color photos. This study used an airborne hyperspectral image to map sericea and its invasiveness in a public grass field in Mid-Missouri. The maximal 1st-order derivative in red-near infrared region (650–800nm) was derived to separate sericea from fescue, the dominant grass in pastures in Missouri. With a simple threshold approach, sericea of various sizes were identified in the study area. It was also found that the maximal 1st-order derivatives of sericea patches were log-linearly related to sericea “volume,” a quasi 3-dimensional biophysical variable as an approximate measure of sericea invasiveness. The squared correlation coefficient (r ²) of the regression was 0.65 and the estimation error of sericea “volume” estimation was 11% based on ground measurements at 27 sample sites. With this empirical regression model, the quantitative distribution of sericea volume was mapped, which could serve as a first step in alerting landowners and the general public about the seriousness of sericea invasion in Missouri pasturelands.     

Disaster management and mitigation: the telecommunications infrastructure

Among the most typical consequences of disasters is the near or complete collapse of terrestrial telecommunications infrastructures (especially the distribution network–the 'last mile') and their concomitant unavailability to the rescuers and the higher echelons of mitigation teams. Even when such damage does not take place, the communications overload/congestion resulting from significantly elevated traffic generated by affected residents can be highly disturbing. The paper proposes innovative remedies to the telecommunications difficulties in disaster struck regions. The offered solutions are network-centric operations-cap able, and can be employed in management of disasters of any magnitude (local to national or international). Their implementation provide ground rescue teams (such as law enforcement, firemen, healthcare personnel, civilian authorities) with tactical connectivity among themselves, and, through the Next Generation Network backbone, ensure the essential bidirectional free flow of information and distribution of Actionable Knowledge among ground units, command/control centres, and civilian and military agencies participating in the rescue effort.     

旅游目的地映象的对应分析--以江西庐山、龙虎山、三清山、井冈山为例

应用对应分析方法对江西省庐山、龙虎山、三清山、井冈山的16个旅游映象属性进行了分析。结果表明：庐山、龙虎山、三清山游客对江西旅游地映象最深的是名山风光、自然生态、名胜古迹，井冈山游客对江西旅游地映象最深的是革命胜地、名山风光、自然生态。从综合来看，四山游客对江西省旅游地映象的共性是名山风光、自然生态、革命胜地、名胜古迹位于前列，对宗教、其他、特色旅游、人造映象不深。四山旅游资源映象与其旅游资源特色及其产品密切相关，但不完全一致。与传统的调查数据的一般分析相比，对应分析方法研究旅游地映象具有优良的特性。在本研究中以图示方式简明直观地揭示了旅游目的地映象的总体特征、不同旅游目的地映象的差异性与相似性，对于旅游竞争市场开发规划有实际应用意义。     

卫星浮标天线技术及其在潜艇通信中的应用

结合目前卫星浮标天线的发展情况，重点介绍了可回收光纤系留浮标系统。简要阐述了该系统的概念，并对该系统的结构、工作原理、数据传输能力以及布放和回收过程进行分析，最后对该系统的未来载荷和最新进展进行了论述。     

利用遥感监测青藏高原上空臭氧总量30 a的变化

利用多源卫星遥感数据,分析了自1979年以来青藏高原上空臭氧总量的时空动态特征.结果表明,青藏高原上空的臭氧总量还在持续下降,而且下降速度高于全球和北半球平均水平,青藏高原、全球和北半球每年大约平均减少0.23%、0.19%、0.12%.但是自2000年后,下降的速度有所减缓,1979～1989、1990～1999和2000～2008年3个时期每年减少大约分别为0.51%、0.49%、0.31%.30a来青藏高原上空臭氧总量低于240DU的天数有34d.在2005年后,没有出现大面积的臭氧总量低值区(低于240DU);臭氧总量的季节变化呈正弦曲线变化,最大和最小值分别出现在3和10月,平均值分别大约为304.59和265.45DU.但是每年的极小值常出现在11月或12月.臭氧总量波动最大和最小分别出现在2月和9月,标准差为17.28和5.88DU;臭氧总量与海拔高度呈反相关,低值区出现在高海拔的上空,特别是在青藏高原区,与同纬度圈的平均值相比,青藏高原臭氧总量大约低了19DU,形成臭氧低谷.     

Estimation of Southeast Asian rice paddy areas with different ecosystems from moderate-resolution satellite imagery

Multi-temporal satellite imagery from the Moderate Resolution Imaging Spectrometer (MODIS) was used to map the different ecosystems of Southeast Asian (SEA) rice paddies. The algorithm was based on temporal profiles of vegetation strength and/or water content, using MODIS surface reflectance in visible to near-IR range. The results obtained from the analysis were compared to national statistics. Estimated SEA regional rice area was 42 × 10⁶ ha, which agrees with published values. The model performance was dependent on rice ecosystems. Good linear relationships between the model results and the national statistics were observed for rainfed rice. High linear coefficients of determination, R², were also found for irrigated rice and upland rice, but the model tended to underestimate irrigated rice and overestimate upland rice. However, these high R² values indicated that the model effectively simulated spatial distribution of these rice areas. These R² values were either of similar magnitude or larger than those reported in literature, regardless of the rice ecosystem. Poor correlation was observed for deepwater rice.