基于OpenLayers和MongoDB的船舶信息管理系统开发

船舶数据的管理和可视化对航道、船舶管理具有重要意义。大量快速更新的船舶位置信息和影像数据,对数据存储、检索以及可视化提出了较高的要求。本文结合实际应用需求,基于非关系型数据库MongoDB和开源地图API设计并开发船舶信息管理系统。该系统将船舶和热点区域数据存储在MongoDB中,可在浏览器中高效同步显示大量空间数据,提供属性查询、空间检索和统计制图等功能,并且可在线编辑数据库中的热点区域数据。本系统主要解决了MongoDB数据库中空间数据高效检索,BSON文档格式和Geo JSON地理要素格式的转换,数据库中空间数据在线编辑等问题,为船舶信息化管理提供了支持。     

Comparison and interpretation of graphitization in contact and regional metamorphic rocks

Abstract X-ray diffraction (XRD) analyses of carbonaceous materials were carried out in conjunction with petrological studies for selected metamorphic rocks in order to compare the structural state of carbonaceous materials between contact and regional metamorphic rocks. The most extensive study was done for the Daimonji contact aureole in the eastern part of Kyoto city, Japan. The Daimonji contact aureole can be divided into three mineral zones using mineral parageneses of pelitic rocks: chlorite, biotite and cordierite zones. The cordierite zone can be further subdivided into lower- and higher-grade subzones. Petrological considerations allow the two isograd reactions that define the lower- and higher-grade cordierite subzones to be determined and suggest these reactions occurred at 510–560°C and 560–590°C per 2.0-2.3 kbar, respectively. A combination of the petrological studies and the XRD data of carbonaceous materials suggest that fully ordered graphite (FG; defined by d(002) ≤ 3.360 Å following the convention used by many workers), appears around 560–590°C in the Daimonji contact aureole. This data and refinement of geothermometer for published data confirmed that the FG appears at 400–500°C in regional metamorphic rocks, but at higher than 530°C in contact aureoles. One possible explanation for such a temperature difference is the duration of heating. However, the width at half height (WH) of the graphite peak attains a similar value of 0.30° at around 500°C both in contact and regional metamorphic rocks, suggesting that WH value is a more reliable indicator of metamorphic grade than the change of d(002) value. Furthermore, the depressed d(002) data of graphite was observed locally in the higher grade part (≥ 500°C) of the Ryoke regional metamorphic belt, where granitic intrusions exist within a few km distance. These facts indicate that the duration of heating is not an important factor controlling the change of d(002) value. It is possible that interlayered impurities, such as chlorine, which was derived from igneous intrusions, may be an important factor in suppressing the reduction in d(002) at temperatures greater than 500°C.     

水上钻探作业平台的制作及应用

针对岳城水库库区水下煤炭资源勘探难题，介绍了水上勘探作业平台的制作运输、安装程序和方法，指出了钻探施工应注意的问题。该区共施工了5个地质钻孔和1个水文孔，特、甲级率达到100％，完成了库区水上勘探任务，为解决库区内勘探难题提供了例证。     

基于小波的被动声纳降噪研究

基于小波的降噪理论,研究了水下舰船辐射噪声的被动声纳降噪问题。通过对船辐射噪声的建模和仿真,分析对比了不同方法对舰船辐射噪声信号降噪的效果,并利用各种小波基和采用不同阈值条件下对信号进行降噪处理的效果。该研究在分析对比的基础上,进行小波包软阈值去噪并且取得了较好的效果,对被动声纳降噪提供了较好的应用前景。     

稳定井流直线图解法确定含水层参数

对于潜水井流,利用Dupuit公式计算的参数往往相差很大,难以直接选用。对Dupuit公式进行线性化,建立降深(s)与距离(r)的s-lnr直线关系,利用直线斜率、直线在x轴上的截距,可以直接求得唯一的渗透系数K和影响半径R。利用松花江河谷的承压水井抽水试验资料和洮儿河扇形地27个潜水抽水井及其观测孔的抽水试验资料,应用直线图解法分析计算,得到唯一的含水层参数T、K和R。将计算结果与直接利用Dupuit公式所计算的结果相比较,前者的求参效果较好。     

1402（3）综采工作面压架原因分析

1402(3)回采工作面(缩小防水煤柱开采的首采面)在开采过程中，先后出现2次综采压架事故，通过对该面综采压架原因多角度的分析研究，认为在目前的装备条件和管理水平下，上提阶段工作面完全可以采用综采回采．为指导今后潘谢矿区上提阶段回采工作面的安全生产工作提供了依据。     

Identification-based simplified model of large container ships using support vector machines and artificial bee colony algorithm

The 6 degrees of freedom (DOF) model with a high degree of complexity for capturing ship dynamics is generally able to track the nonlinear and coupling dynamics of ships. However, the 6 DOF model makes challenges in estimating model coefficients and designing the model-based control. Therefore, simplified ship dynamic models within allowed accuracy are essential. This paper simplified the 6 DOF nonlinear dynamic model of ships into two decoupled models including the speed model and the steering model through reasonable assumptions. Those models were tested through maneuvering simulations of a container ship with a 4 DOF dynamic model. Support vector machines (SVM) optimized by the artificial bee colony algorithm (ABC) was used to identify parameters of speed and steering models by analyzing the rudder angle, propeller shaft speed, surge and sway velocities, and yaw rate from simulated data extracted from a series of maneuvers made by the container ship. Comparisons with the first order linear and nonlinear Nomoto models show that the simplified nonlinear steering model can capture more complicated dynamics and performs better. Additionally, comparisons among three different parameter identification methods demonstrate similar identification results but the different performance involving the applicability and effectiveness. SVM optimized by ABC is relatively convenient and effective for parameter identification of ship simplified dynamic models.     

容器固有频率对液体晃荡的影响

针对矩形容器内液体晃荡问题,采用了时域高阶边界元方法建立自由水面满足完全非线性边界条件的数学模型。求解中采用混合欧拉-拉格朗日方法追踪流体瞬时水面,运用四阶龙格库塔方法更新下一时间步的波面和速度势。通过将计算得到的波面结果与实验数据、解析解和已发表结果对比,吻合良好,验证了本方法的准确性。进而采用谱分析方法分析了波面时间历程,得到容器各阶固有频率对液体晃荡的影响。研究发现,基频对液体晃荡的影响最大,且非线性越强,更高阶容器固有频率的影响越大。     

纵向地震作用下通航渡槽碰撞特征研究

通航渡槽与升船机是过坝的快速通道。通航渡槽具有墩高由高到低连续变化、升船机与相邻高墩区渡槽基本周期差异大的结构特点,属于地震下激烈碰撞易发结构。基于有限元模型,对通航渡槽进行碰撞特征、控制因素以及地震响应影响研究。研究结果表明:渡槽与升船机周期差异大是造成剧烈碰撞的主要因素,且此碰撞有明显的传递效应;具有大位移的高墩在相邻渡槽跨周期差异不大时也会造成剧烈的碰撞,是碰撞的另一主要控制因素;有别于桥梁结构中碰撞通常限制墩的位移,通航渡槽中靠近升船机的剧烈碰撞区域,出现了明显的槽墩位移放大现象;碰撞对支座剪力影响程度远大于墩底剪力、弯矩。     

Dense RFB和LSTM遥感图像舰船目标检测

针对当前遥感图像舰船目标检测精度不佳问题,本文构建舰船目标数据集STAR,提出基于Dense RFB和LSTM多尺度舰船目标检测算法。该算法首先在SSD网络基础上设计了浅层特征增强模块,基于人眼视点图采用Dense RFB特征复用和膨胀卷积增大感受野的尺度和种类,增强浅层网络对细节特征的提取能力;其次设计了深层多尺度特征金字塔融合模块,采用FPN和LSTM思想,基于反卷积和残差网络对深层不同尺度特征进行融合,增强网络结构非线性和特征层的表征能力;最后加入聚焦分类损失函数进行联合训练,有效避免了正负样本失衡问题。在遥感图像舰船数据集上实验,本文所提舰船目标检测算法精度均值达到81.98%,检测速度达到29.6帧/s。此外,遥感图像中成像模糊、被遮挡、部分被裁剪等舰船目标的检测效果也优于原有经典算法,实验结果表明该算法对遥感图像舰船目标检测的泛化能力较强,有效地提高了遥感图像舰船目标检测的精度。