How to determine the optimum location of in-pit movable crushers     

John R. Sturgul 《Geotechnical and Geological Engineering》1987,5(2):143-148

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支承压力显现的动态规律与来压预报方法   总被引：1，自引：0，他引：1  

蒋金泉  谭云亮 《工程地质学报》1994,2(3):72-80

本文以DKJ-1型矿压计算机监测系统在两个矿的顶板来压监测和预报实际资料为依据,深入分析了8个月,13次来压的支承压力显现规律,并将显现形式分为压缩反弹型和波动型两种类型,总结了显现的特征参数及与来压的时间差和位置差。文章介绍了计算机监测系统识别来压前兆的方法及准确预报13次来压的良好效果。  相似文献   

浅析计算机病毒对气象业务网络的危害与防范          下载免费PDF全文

龚贤创 《应用气象学报》2003,14(3):375-378

简要地介绍了对气象业务网络危害极大的计算机病毒，分析了计算机病毒发展的趋势。介绍了武汉气象中心防病毒系统的设计及实践。表明“分组、分级”管理模式的计算机病毒防御系统能有效地抵御病毒对网络的进攻，保证气象业务正常运行。  相似文献   

呼叫中心在气象系统中的应用研究   总被引：2，自引：0，他引：2  

张璞  任岗  李扬 《沙漠与绿洲气象(新疆气象)》2003,26(3):26-27,33

从呼叫中心的产生背景入手，分析了呼叫中心在气象服务中应用的必要性，并从应用的角度对系统结构及系统功能等进行了简单的介绍。  相似文献   

Computer vision applied to wave flume measurements     

G. Iglesias  O. Ibáñez  J.R. Rabuñal 《Ocean Engineering》2009,36(14):1073-1079

A new measurement system for laboratory wave flumes is presented, based on the analysis of digital images by means of computer vision techniques. Unlike conventional wave gauges, the system detects the motions of the free surface along the flume section of interest as opposed to a point. A further advantage lies in that no sensors are necessary within the flume. The system is particularly useful in the case of wave flume tests of floating bodies, such as an oil boom—the motions of the model boom are measured without any sensors in contact with it, which otherwise might place constraints on its displacements. The new method is validated based on free surface measurements carried out with a conventional wave gauge, with excellent results.  相似文献   

浅谈计算机机房布线与防雷   总被引：3，自引：2，他引：1  

孙国量 《内蒙古气象》2009,(1):47-48

文章主要讲述机房在设计和施工中需要考虑与布线的关系以及应当注意的一些事项,是作者在工程实践防雷中对机房布线和防雷工作的一些认识,仅供参考。  相似文献   

An equal-area map projection for irregular objects     

M.G. Berthoud 《Icarus》2005,175(2):382-389

An increasing number of objects discovered in the Solar System have irregular shapes which require unconventional mapping techniques. Here we present a technique that produces equivalent maps of such objects. As such maps preserve surface area they are especially useful for mapping the distribution of geological features on irregular objects. Maps of blocks and craters on the Asteroid 433 Eros are used to illustrate the potential use of the technique. Two equal-area maps are adequate to cover the entire asteroid and convincingly demonstrate variations in surface density of mapped features. Similar coverage by orthographic views requires 4 to 6 plots. The distortion of the maps are comparable to the distortions of maps created by other techniques.  相似文献   

长江中上游灾害性天气自动气象站网监测系统研究     

高贤来  鲁明响  黄克俭 《成都信息工程学院学报》1992,(3)

本文系统地介绍了我国研制的自动气象站网的组成、功能及其特点,论述了自动气象站网、无线传输网及计算机通信网的设计方法和联接技术。  相似文献   

Photometric modeling of Saturn's rings: I. Monte Carlo method and the effect of nonzero volume filling factor     

Heikki Salo  Raine Karjalainen 《Icarus》2003,164(2):428-460

The scattering properties of particulate rings with volume filling factors in the interval D=0.001-0.3 are studied, with photometric Monte Carlo ray tracing simulations combining the advantages of direct (photons followed from the source) and indirect methods (brightness as seen from the observing direction). Besides vertically homogeneous models, ranging from monolayers to classical many-particle thick rings, particle distributions obtained from dynamical simulations are studied, possessing a nonuniform vertical profile and a power law distribution of particle sizes. Self-gravity is not included to assure homogeneity in planar directions. Our main goal is to check whether the moderately flattened ring models predicted by dynamical simulations (with central plane D>0.1) are consistent with the basic photometric properties of Saturn's rings seen in ground-based observations, including the brightening near zero phase angle (opposition effect), and the brightening of the B-ring with increasing elevation angle (tilt effect). Our photometric simulations indicate that dense rings are typically brighter in reflected light than those with D→0, due to enhanced single scattering. For a vertically illuminated layer of identical particles this enhancement amounts at intermediate viewing elevations to roughly 1+2D. Increased single scattering is also obtained for low elevation illumination, further augmented at low phase angles α by the opposition brightening when D increases: the simulated opposition effect agrees very well with the Lumme and Bowell (1981, Astron. J. 86, 1694-1704) theoretical formula. For large α the total intensity may also decrease, due to reduced amount of multiple scattering. For the low (α=13°) and high (α=155°) phase angle geometries analyzed in Dones et al. (1993, Icarus 105, 184-215) the brightness change for D=0.1 amounts to 20% and −17%, respectively. In the case of an extended size distribution, dynamical simulations indicate that the smallest particles typically occupy a layer several times thicker than the largest particles. Even if the large particles form a dynamically dense system, a narrow opposition peak can arise due to mutual shadowing among the small particles: for example, a size distribution extending about two decades can account for the observed about 1° wide opposition peak, solely in terms of mutual shadowing. The reduced width of the opposition peak for extended size distribution is in accordance with Hapke's (1986, Icarus 67, 264-280) treatment for semi-infinite layers. Due to vertical profile and particle size distribution, the photometric behavior is sensitive to the viewing elevation: this can account for the tilt-effect of the B-ring, as dense and thus bright central parts of the ring become better visible for larger elevation, whereas in the case of smaller elevation, mainly low volume density upper layers are visible. Since multiple scattering is not involved, the explanation works also for albedo well below unity. Inclusion of nonzero volume density helps also to model some of the Voyager observations. For example, the discrepancy between predicted and observed brightness at large phase angles for much of the A-ring (Dones et al., 1993, Icarus 105, 184-215) is removed when the enhanced low α single scattering and reduced large α multiple scattering is allowed for. Also, a model with vertical thickness increasing with saturnocentric distance offers at least a qualitative explanation for the observed contrast reversal between the inner and outer A-ring in low and high phase Voyager images. Differences in local size distribution and thus on the effective D may also account for the contrast reversal in resonance sites.  相似文献   

地物杂波区内不同速度方差降雨回波信号损失比计算与分析     

阎邦华 《成都信息工程学院学报》1989,(2)

本文对地物杂波区内不同速度方差的降雨回波信号经非相干MTI对消系统(地物杂波抑制器)输出后的交流功率变化(降雨回波损失比),作了详尽的理论计算和分析,提出了对该降雨回波信号的损失进行相应的补偿即能获取误差较小的地物杂波区内降雨回波信息的观点。使有效抑制地物杂波的非相干MTI技术应用更加广泛,有助于最终实现地物杂波区内降雨回波定量化。  相似文献