基于机器学习的格点气温预报订正方法

使用2017年9月至2021年3月国家级业务化运行的智能网格实况分析产品和欧洲中期天气预报中心全球模式(EC)产品,根据湖北省的地理分布特征构建6个分区,采用基于LightGBM机器学习算法建立的气温预报方法,生成湖北省0.05°×0.05°格点气温预报产品。利用2021年4—9月的预报产品和格点实况资料进行检验,结果表明:基于机器学习的气温预报方法(MLT)取得了较好的预报效果,其在0～72 h时效内优于中央气象台下发的气温精细化指导预报(SCMOC)和EC产品;MLT在山区的误差较平原大,但山区的订正幅度大于平原,日最高气温的订正幅度大于日最低气温的订正幅度;4—9月MLT、SCMOC、EC产品的平均绝对误差(MAE)日变化都呈现了白天偏高、夜间偏低、午后凸起的单峰特征,MLT的MAE值较SCMOC和EC产品的更低,并且在转折性天气中仍具有优势;站点检验与格点检验结论一致,基于格点建模的气温预报产品对站点预报同样得到了订正。机器学习在格点气温的模式订正方面可以作为一个行之有效的手段。     

离心式泥浆机械净化设备的研制与应用

本文介绍了两种离心式泥浆净化设备——NL-227型离心除泥器和WL-230型连续除泥离心机的结构、特点和应用效果,讨论了几种净化设备的分离物的粒度分布.     

A Diagnostic Study of Explosive Development of Extratropical Cyclone over East Asia and West Pacific Ocean

ＡＤｉａｇｎｏｓｔｉｃＳｔｕｄｙｏｆＥｘｐｌｏｓｉｖｅＤｅｖｅｌｏｐｍｅｎｔｏｆＥｘｔｒａｔｒｏｐｉｃａｌＣｙｃｌｏｎｅｏｖｅｒＥａｓｔＡｓｉａａｎｄＷｅｓｔＰａｃｉｆｉｃＯｃｅａｎ￥ＪｉａＹｉｑｉｎ（贾逸勤）ａｎｄＺｈａｏＳｉｘｉｏｎｇ（赵思雄）（...     

地下管线探测的基本原理及解释方法研究

本文较详细地讨论了电磁直接探测法探测地下管线的基本原理和解释方法;提出了一种新的求解管线位置和深度、并给出探测结果可信度的向量交绘法。现场提供高可信度的结果;对管线探测仪器设备及应用效果作了介绍。     

云南耿马7.2级地震地表破裂带研究

根据野外考察的实际资料,本文介绍了耿马7.2级地震地表破裂带的展布,结构要素及组合、位移分布等情况。同时依据位错资料对破裂带的应力活动及断裂两盘的运动状态进行了初步分析。认为本次地震发震构造以右旋走滑为主兼具张性,主压应力优势方位为N5°—10°E。断层两盘相对运动的总体方向为N55°W左右,断层运动的滑移角在30°—40°之间     

栅格图形数据叠置分析方法及其在城镇规划中应用

本文介绍用栅格数据进行图形叠置分析的方法,提出矢量数据转换为栅格数据的链拓扑法、减少栅格数据存储量的编码方法、根据模糊综合评判原理建立多因素综合评价数学模型以及叠置评价结果的类型格网合并的边界跟踪算法,最后给出一个实例说明栅格图形数据叠置分析方法在城镇规划中的应用。     

硬玉位错滑移系及流变学特征的研究

本文所研究的硬玉采自Ｓｅｓｉａ－Ｌａｎｚｏ带（阿尔卑斯意大利段）。该带经历了高压低温榴辉岩相变质，其变质温压为５５０℃～６００℃，１．５～１．６ＧＰａ。应用透射电子镜精细研究硬玉单晶的位错特征尚属首次，研究结果表明经天然变形的硬玉单晶中，发育有大量自由位错、位错壁、亚晶粒。自由位错密度大约为１×１０８／ｃｍ２，以刃型位错为主，也发育有少量螺位错。刃位错的伯氏矢量ｂ为［００１］和［１１０］（ｂ＝７．１６Ａ；１／２（ａ＋ｂ）＝６．６Ａ）。     

人工心肺机流量计的研制

本文介绍了如何应用单片微型计算机和光电传感器组成人工心肺机(或称体外循环机)流量计。该仪器对人工心肺机的泵的各种转速能够准确地采集,对不同的患者能够精确地计算出所需血液流量,从而定量地控制输送给病人的血液流量,以保证心脏手术顺利进行,改变了临床手术时手工计算的落后情况。流量计是一台新型的智能化仪表。     

An equal area conversion model for rasterization of vector polygons

Vector-raster conversion is one of the classic research topics in the field of Geographical Information Systems (GIS). The algorithms commonly used in GIS are devoted to maintaining the vector polygons' shape characteristics, but neglect the gain and loss of a polygon's area, which is another important attribute. This paper proposes an equal-area conversion model based on an area compensation optimization principle. According to the topological relationship among polygons and boundary grids, a neighborhood compensation principle was adopted to assign the attributes of boundary grids and a global optimization algorithm was developed to minimize area distortion in the whole data set. Two experiments were designed and the results indicated that this algorithm not only guaranteed the area error is as small as possible, but also has the advantage as being adaptive to polygon shape and spatial structure.     

Non‐linear system identification of the versatile‐typed structures by a novel signal processing technique

Non‐linear structural identification problems have raised considerable research efforts since decades, in which the Bouc–Wen model is generally utilized to simulate non‐linear structural constitutive characteristic. Support vector regression (SVR), a promising data processing method, is studied for versatile‐typed structural identification. First, a model selection strategy is utilized to determine the unknown power parameter of the Bouc–Wen model. Meanwhile, optimum SVR parameters are selected automatically, instead of tuning manually. Consequently, the non‐linear structural equation is rewritten in linear form, and is solved by the SVR technique. A five‐floor versatile‐type structure is studied to show the effectiveness of the proposed method, in which both power parameter known and unknown cases are investigated. Copyright © 2007 John Wiley & Sons, Ltd.