基于模拟退火算法的自动地图注记配置研究   总被引：2，自引：0，他引：2  

罗广祥  马智民  田永瑞 《测绘科学》1999,(2)

本文将求解大规模组合优化问题最优解的一种新型算法模拟退火算法应用于地图注记的自动配置。该算法将地图各要素注记的配置作为一个统一的整体来对待,从而避免了一般局部搜索法可能终止于一个局部最优解的缺点,这样可使自动注记配置的结果更趋合理化。用模拟退火算法进行注记自动配置,理论体系完整,机理简单,通用性强,编程容易,而且与一般局部搜索法相比,超常规注记配置出现的数目大大降低,其缺点在于配置速度较慢  相似文献   

Monitoring qualitative spatiotemporal change for geosensor networks     

Mike Worboys  Matt Duckham 《International journal of geographical information science》2013,27(10):1087-1108

Recent technological advances in geosensor networks demand new models of distributed computation with dynamic spatial information. This paper presents a computational model of spatial change in dynamic regions (such as may be derived from discretizations of continuous fields) founded on embeddings of graphs in orientable surfaces. Continuous change, connectedness and regularity of dynamic regions are defined and local transition rules are used to constrain region evolution and enable more efficient inference of a region's state. The model provides a framework for the detection of global high‐level events based on local low‐level ‘snapshot’ spatiotemporal data. The approach has particular relevance to environmental monitoring with geosensor networks, where technological constraints make the detection of global behaviour from local conditions highly advantageous.  相似文献   

Microseismic events enhancement and detection in sensor arrays using autocorrelation‐based filtering          下载免费PDF全文

Entao Liu  Lijun Zhu  Anupama Govinda Raj  James H. McClellan  Abdullatif Al‐Shuhail  SanLinn I. Kaka  Naveed Iqbal 《Geophysical Prospecting》2017,65(6):1496-1509

Passive microseismic data are commonly buried in noise, which presents a significant challenge for signal detection and recovery. For recordings from a surface sensor array where each trace contains a time‐delayed arrival from the event, we propose an autocorrelation‐based stacking method that designs a denoising filter from all the traces, as well as a multi‐channel detection scheme. This approach circumvents the issue of time aligning the traces prior to stacking because every trace's autocorrelation is centred at zero in the lag domain. The effect of white noise is concentrated near zero lag; thus, the filter design requires a predictable adjustment of the zero‐lag value. Truncation of the autocorrelation is employed to smooth the impulse response of the denoising filter. In order to extend the applicability of the algorithm, we also propose a noise prewhitening scheme that addresses cases with coloured noise. The simplicity and robustness of this method are validated with synthetic and real seismic traces.  相似文献   

后向散射系数测量仪实验室定标技术     

李刚  汪小勇 《海洋技术学报》2004,23(4):127-129

水体后向散射系数(bb)是水色遥感的重要参数之一,其现场准确测量的关键是测试仪器的严格定标。文章将针对我们从美国Hobilabs公司引进的HS-6后向散射测量仪的实验室定标和定标中的注意事项、数据结果分析以及自然光对实验室定标的影响进行阐述。  相似文献   

Experimental analysis of breakwater stability with antifer concrete block     

S. Hooman Mousavi  M. R. Kavianpour  O. Aminoroayaie Yamini 《Marine Georesources & Geotechnology》2017,35(3):426-434

Armor is a pavement made of erosion-resistant materials like a stone or concrete that is constructed to protect breakwater, coasts, and other coastal line features against erosion. These armors are a kind of protective layer made of stone or concrete, used in breakwater constructions or coastal lines, arrayed with specific regular or irregular pattern on the breakwater or the coast. The antifer concrete blocks have almost cubic form, often changed into frustum by adding inclined plates to their sides. One of the most important advantages of these armors is their diversified regular and irregular placement patterns. In this study, using the physical modeling and different tests, the stability level of antifer concrete blocks was evaluated considering the decrease of the armor weight. Results of this study show that by a 10% decrease in the block weight, the failure graph slope is increased and the damage is intensified.  相似文献   

Efficient Bayesian sensor placement algorithm for structural identification: a general approach for multi‐type sensory systems          下载免费PDF全文

Ka‐Veng Yuen  Sin‐Chi Kuok 《地震工程与结构动力学》2015,44(5):757-774

In this paper, a Bayesian sequential sensor placement algorithm, based on the robust information entropy, is proposed for multi‐type of sensors. The presented methodology has two salient features. It is a holistic approach such that the overall performance of various types of sensors at different locations is assessed. Therefore, it provides a rational and effective strategy to design the sensor configuration, which optimizes the use of various available resources. This sequential algorithm is very efficient due to its Bayesian nature, in which prior distribution can be incorporated. Therefore, it avoids the possible unidentifiability problem encountered in a sequential process, which starts with small number of sensors. The proposed algorithm is demonstrated using a shear building and a lattice tower with consideration of up to four types of sensors. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

地磁房湿度对地磁观测的影响及解决方案     

郅红魁  郭慧  耿淑芬  阴宏业  程楠  宋建锁 《中国地震》2015,31(2):409-414

地磁房湿度变化较快或过大都易引起地磁数据的异常变化,且室内湿度不易控制,地磁房、磁通门磁力仪探头湿度智能在线分析监控系统可以实时显示监控地磁房、磁通门磁力仪探头湿度的变化,超过湿度阈值则发出报警信号,进而可以采用科学的方法控制探头观测环境的湿度,提高观测数据的稳定性、可靠性。本文介绍了该系统的设计思路和主要功能。  相似文献   

瞬变电磁传感器阻尼特性的标定研究   总被引：3，自引：2，他引：1       下载免费PDF全文

张爽  刘紫秀  陈曙东 《地球物理学报》2014,57(2):662-670

传统瞬变电磁法（TEM）认为临界阻尼匹配时传感器响应快、无振荡,为最佳匹配方式.本文通过建立基于标定环的TEM系统标定模型,理论证明当略欠阻尼匹配时传感器响应最快、时域畸变最小,为最佳匹配方式.本文采用基于实测数据的背景场剔除方法将一次场和大地响应剔除,通过对不同阻尼状态下标定环早期响应畸变的定量评价,实验证明传感器在略欠阻尼匹配状态下二次场响应畸变最小.本文理论和标定实验均证明,在纯二次场观测方式下,采用略欠阻尼匹配方式能够显著降低早期响应畸变、提高系统浅层探测能力,是浅层探测时传感器最佳匹配方式.  相似文献   

典型滑坡监测点优化布置   总被引：1，自引：0，他引：1  

王洪德  高幼龙  薛星桥  金枭豪  王刚 《吉林大学学报(地球科学版)》2013,43(3):858-866

利用数值模拟技术与模糊模式识别算法提出了滑坡监测点优化布置的基本方法。以链子崖危岩体为例,以Ⅳ-Ⅳ′剖面作为滑坡监测点优化布置的典型剖面,根据监测变量（位移）对外界干扰因素作用下的灵敏度大小与监测信息量获取大小之间的关系,对该危岩体的监测变量（位移）进行了灵敏度分区研究,进而对该典型剖面的监测点进行了优化设计。研究结果表明,链子崖危岩体地表位移监测点宜布置在位移量明显和状态变化灵敏度较高的部位,深部位移监测钻孔宜穿越所有水平位移变化的灵敏区域。  相似文献   

碎石桩处理软土地基临界填筑高度的研究     

陈继彬  赵其华  彭社琴 《岩土力学》2015,36(2):470-476

目前计算碎石桩处理软土地基临界填筑高度的方法并不完善,没有考虑软基经碎石桩处理后复合地基强度的增加和地基排水固结能力的提高,基于此,依据固结理论,引入碎石桩复合地基固结计算的简化方法,修正按变形控制的临界填筑高度计算公式;并结合四川省遂-资高速公路软基变形监测数据,得出软基厚度在6.5～11.0 m范围内,观测所得的临界填筑高度为4.5～6.5 m,该观测值与修正公式计算值差异性不显著,证实所推导的解析式是切实可行的;在此基础上,初步探讨影响路堤临界填筑高度变化的因素,得出软基厚度、桩间距对其影响较为明显。  相似文献