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《Oceanic Engineering, IEEE Journal of》2009,34(4):586-602
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多传感器信息融合技术是对各个传感器的观测数据进行综合处理的过程,是多学科、多领域的高层次共性关键技术。以多源信息融合技术为基础,对 AIS、雷达与声呐多源探测信息融合算法进行了较为深入地研究,提出适应水下安防系统的多源信息融合与报警技术的工程化应用方案,对实际应用情况做了简要总结,经验证该技术能够较好应用于水下安防系统的数据分析和分级报警中。 相似文献
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闭合多边形的旋转方向判定是GIS空间分析和算法中较重要的内容之一,由于现在算法较多,其算法的效率和精确度参差不一。对比分析了基于凸包的闭合多边形旋转算法、基于多边形面积计算的闭合多边形旋转算法和基于凹凸顶点判定方法的闭合多边形旋转算法,从算法设计复杂程度、算法效率等方面进行了详细阐述,指出了基于凹凸顶点判定方法是最简单最有效的一种判定方法。 相似文献
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Conrad W. Curry Richard H. Bennett Matthew H. Hulbert Kenneth J. Curry Richard W. Faas 《Marine Georesources & Geotechnology》2004,22(4):231-252
Porosity is a fundamental property of marine sediment from which wet bulk density can be easily determined and used in a variety of geoacoustic, geotechnical, and sedimentological studies, analyses, and models. However, methods of sampling marine sands suffer from the common problem of core disturbance making the in situ porosity difficult to obtain. Embedding the sediment within an epoxy resin matrix will minimize the disturbance to the microfabric and preserve the in situ sedimentary structure for subsequent study. Image analysis can then be used on thin sections to study the microfabric and porometry. A comprehensive review and analysis of published data on the porosity of predominantly clean sands has been completed and a simple, accurate, and nondestructive technique is described for preparing and measuring the porosity of marine sediment (siliciclastic sand) that has been infiltrated aboard ship immediately upon sample collection and chemically fixed and infiltrated with epoxy shortly thereafter. The average porosity of 36 samples of marine sand collected offshore Fort Walton Beach, Florida, and embedded with resin was determined to be 41.30%. From the review of published data the average porosity of sand was determined to be 37.7%, 42.3%, and 46.3% for packed, natural (in situ), and loose packing conditions, respectively, for a range of sorting coefficients and grain sizes. 相似文献
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Conrad W. Curry Richard H. Bennett Matthew H. Hulbert Kenneth J. Curry Richard W. Faas 《Marine Georesources & Geotechnology》2013,31(4):231-252
Porosity is a fundamental property of marine sediment from which wet bulk density can be easily determined and used in a variety of geoacoustic, geotechnical, and sedimentological studies, analyses, and models. However, methods of sampling marine sands suffer from the common problem of core disturbance making the in situ porosity difficult to obtain. Embedding the sediment within an epoxy resin matrix will minimize the disturbance to the microfabric and preserve the in situ sedimentary structure for subsequent study. Image analysis can then be used on thin sections to study the microfabric and porometry. A comprehensive review and analysis of published data on the porosity of predominantly clean sands has been completed and a simple, accurate, and nondestructive technique is described for preparing and measuring the porosity of marine sediment (siliciclastic sand) that has been infiltrated aboard ship immediately upon sample collection and chemically fixed and infiltrated with epoxy shortly thereafter. The average porosity of 36 samples of marine sand collected offshore Fort Walton Beach, Florida, and embedded with resin was determined to be 41.30%. From the review of published data the average porosity of sand was determined to be 37.7%, 42.3%, and 46.3% for packed, natural (in situ), and loose packing conditions, respectively, for a range of sorting coefficients and grain sizes. 相似文献
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V. A. Dulov V. N. Kudryavtsev V. I. Shrira V. E. Smolov A. N. Bol’shakov 《Physical Oceanography》2007,17(1):29-40
We describe the procedure of field experiments aimed at measuring the vertical profiles of the vectors of a drift current
with the help of quasi-Lagrangian drifters. We present the data on the vertical shears of the current at depths of 0.5–5 m
obtained under the conditions of neutral stratification in the upper 5-m layer of the sea in the presence of weak and moderate
winds. The correspondence of the obtained data to the concept according to which the subsurface layer of the sea is regarded
as a near-wall turbulent layer with Ekman current located below is analyzed. A conclusion is made that the results of measurements
correspond, on the average, to the classical concepts demonstrating both the region of logarithmic sublayer and its transition
into the Ekman spiral.
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Translated from Morskoi Gidrofizicheskii Zhurnal, No. 1, pp. 32–44, January–February, 2007. 相似文献
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定位定向技术是深海作业系统的主要关键技术之一。本文基于激光陀螺提出了一种用于深海作业的高精度定位定向系统研究方案,建立了一套相应的系统分析方法,对该方案的姿态、速度、位置误差进行了详细的仿真分析。进行了72 h静态定位定向实验,结果表明系统的俯仰角和横滚角误差小于0.006°,航向角误差小于0.035°,速度误差小于0.9m?s–1,定位误差小于29.9 km。实验结果与仿真分析结果基本一致,验证了该研究方案的可行性。和采用动力调谐陀螺的定位定向系统相比,本系统具有精度高和可靠性好等优点。 相似文献
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The use of ITQ management in multi-species fisheries has been the subject of much debate and the complexities and difficulties of managing multi-species fisheries are well known. A major problem is that the species mix in fishery catches may not necessarily match the mix in combined TACs or in quota holdings. While a number of solutions have been proposed or implemented to improve transferability of quota and other incentives to reduce over-quota fishing and discarding, it is surprising that there has been little focus on TAC-setting itself and coordinating this across multiple species/stocks as a means of dealing with some of these issues. In this paper, data were analysed from the trawl sector of the Australian Southern and Eastern Scalefish and Shark Fishery to determine the relationship between primary species and companion species and the implications this has for TAC setting. The primary species is the species being considered when setting an individual species TAC. The companion species are ones that should also be considered when setting the TAC of the primary species, because a considerable proportion of the primary species catch is taken as a companion species non-target catch. The target species in each fishing operation was determined and was used to characterize recent multi-species catch data into primary and companion components. This approach provides an empirical means to examine the impact of individual species TAC decisions across all of the quota species in a fishery. 相似文献
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南海海山非均匀磁性反演 总被引:3,自引:0,他引:3
利用虚源法对南海海盆 1 6座实测海山进行了磁性反演。结果表明 ,南海海山非均匀磁化反演效果明显优于均匀磁化反演 ;南海海盆东部和西南部的海山运动方向相反 ,前者向北 ,后者往南 ;海山运移中的旋转形式两地也存在明显差异。 相似文献
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QIU Xiaofang PENG Linhui WANG Ning ZHU Jianxiang 《中国海洋工程》2001,(4):589-596
The modal wave number tomography approach is used to obtain sound speed profile of water column in deep ocean. The approach consists of estimation of the local modal eigenvalues from complex pressure field and use of these data as input to modal perturbative inversion method for obtaining the local sound speed profile. The empirical orthonormal function (EOF) is applied to reduce the parameter search space. The ocean environment used for numerical simulations includes the Munk profile as the unperturbed background speed profile and a weak Gaussian eddy as the sound speed profile perturbation. The results of numerical simulations show the method is capable of monitoring the oceanic interior structure. 相似文献
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采用变分资料同化技术,结合最优控制思想,对一个海气耦合模型的模式参数和强迫项进行了反演,结果表明,采用该方法对模式进行优化,既可以补偿模式参数不准确性给预报带来的误差,又可以对模式参数本身进行修正和估计,为将来在实际应用中改善更复杂的预报模式、提高预报准确率提供了一个可借鉴的思路。 相似文献
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The need to estimate the resuspension and deposition of fine-grained sediments and their associated contaminant transport has, in shallow lakes and nearshore areas, called for the measurement of wave data as well as mean flows. Wave statistics recorded by a vector-average current meter over a two-week period are compared to independently measured wave data for a wave-dominated shallow lake at two depths. Wave orbital motions are within 3% of those determined by spectral analysis of frequently sampled currents. Wave propagation directions are within ±19° of spectrally determined directions and qualitatively similar to the fetch-weighted wind direction. Less satisfactory agreement was evident between the wave periods as determined by zero-crossings and the wave spectral peak periods. Reasonable wave periods could be inferred only when the r.m.s. orbital speed exceeded the mean speed. Another possible algorithm for evaluating wave period is tested and recommendations are made for improvements to the measurement system. 相似文献
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Estimation of Geoacoustic Properties of Marine Sediment Using a Hybrid Differential Evolution Inversion Method 总被引:1,自引:0,他引:1
《Oceanic Engineering, IEEE Journal of》2010,35(1):59-69
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以珠江口海域的Radarsatt-2全极化SAR数据和海域表层水面叶绿素a质量浓度实测数据为基础,利用微波散射原理及Cloude Pottier理论对SAR图像进行分解,得到平均散射角a、散射熵H及VH、VV、HH、HV等6个参数;采用BP人工神经网络模型建立上述6个参数与叶绿素a质量浓度的数学关系模型,并结合实测数据对叶绿素a质量浓度进行分类。结果表明:当隐含层节点数为9,输入层和隐含层传递函数分别为tansig和logsig,学习速率和动量系数均为0.2时的网络结构对叶绿素质量浓度反演取得了较好的效果,叶绿素a质量浓度实测值与预测值之间的决定系数(R~2)为0.826。将模型应用于不同时期的2幅图像进行验证,效果良好,与实际情况基本相符。 相似文献
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Zhuravskiy D. M. Prokhorova U. V. Ivanov B. V. Yanjura A. S. Kuprikov N. M. Kurapov M. V. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(9):927-935
Izvestiya, Atmospheric and Oceanic Physics - The results of using an original procedure for estimating albedo from the photogrammetric data and exposure parameters by an unmanned aerial vehicle... 相似文献