Patterns of species composition of beach seine fisheries off North-Western coast of Sri Lanka,fishers’ perceptions and implications for co-management

As in many developing countries, small-scale fisheries including beach seining contribute significantly livelihoods and food security of coastal communities. Beach seining in Sri Lanka is seasonal mainly during calm season deprived of strong monsoonal winds, and essentially a multi-species fishery. Knowledge about the seasonal occurrence of pelagic species is important to be known for proper planning of the fishing activity, especially due to the reason that beach seine fishers in many parts of Sri Lanka make decisions to attach the cod-end of correct type depending on the target species. The possibility of identifying pattern of seasonal occurrence of target fish species in beach seine fishing sites off the southern region of north-western coast of Sri Lanka was therefore investigated using Self Organizing Maps (SOM). The analysis indicated that beach seine fishers’ local knowledge to predict the occurrence of certain species in the fishing sites to adjust their fishing strategies to target desirable species was consistent with the findings of SOM approach. Consequently, it was concluded that as beach seine fishers use indirect indicators such as colour of sea water and behaviour sea birds predict the species occurrence fairly accurately, their local knowledge can be incorporated in the management planning of beach seine fisheries in the North Western coastal area of Sri Lanka.     

DEM精细化处理方法及工艺流程研究

随着社会和经济的快速发展,地理信息产业显现了巨大的发展潜力和无限广阔的前景。DEM作为地信产业非常重要的基础数据,不仅可用于制作数字正射影像、数字三维模型等衍生数据产品,还可以满足不同行业终端用户的应用需求。笔者在DtmExpert软件的基础上,通过对DEM精细化处理方法及工艺流程的深入研究,对传统方法进行了大量改进并应用于地理国情普查等实际生产项目中,取得了良好的效果。采用新的方法及工艺流程后,不仅提升了DEM成果的精细化程度,而且使处理效率提高了5~10倍,形成了具有一定推广价值的研究成果,产生了不错的社会效益和经济效益。     

An averaging method to study the motion of lunar artificial satellites II: Averaging and Applications

On this, the second part of a two part study (Steichen, 1998) we further develop a semi-analytical theory for a lunar artificial satellite. This theory is obtained by averaging analytically the Hamiltonian function over period up to a month. The averaged equations are then numerically integrated. The solution is free from singularities at e = 0 and I = 0 and is not expanded in powers of these variables. In the last section, the analytic work is applied to characteristic examples to validate the method used. This revised version was published online in July 2006 with corrections to the Cover Date.     

城市旅游开发规划进展评述

在总结国内旅游开发规划工作经验的基础上,从理论和实践两方面探讨了综合与整体规划,配套建设,滚动开发的操作模式以及当前旅游开发重点等,强调要突出旅游文化背景和旅游形象策划,并归纳了旅游开发规划需要研究的一系列问题。     

浅谈工程建设监理

首先简要介绍了我国工程建设监理制的建立、运行及发展概况;然后就工程建设监理及监理单位性质、监理模式以及我国实施工程建设监理的有关法律、法规、具体内容等进行了详细阐述;最后指出了工程建设监理与政府工程质量监督的区别。     

人工智能GIS软件技术体系初探

作为人工智能的代表性技术,深度学习已经成为大数据等各个领域中最具有突破性发展的新技术。深度学习的成功主要得益于其新颖的数据驱动的特征表示学习能力,这种能力成功地替代了传统建模中基于领域知识人为设计特征的方式。在这些技术推动下,人工智能技术在新一代GIS基础软件技术的研究与应用中发挥着极为重要的作用,而现有人工智能GIS（AI GIS）技术研究整体仍处于初步探索阶段,距离成熟阶段尚有较大距离。作为新一代GIS基础软件的方法和技术,AI GIS已经广泛应用在遥感数据分析、水资源研究、空间流行病学和环境健康等地学领域,与传统GIS模型相比大大提高了对非结构化的遥感或街景影像和文本的地理信息提取和特征理解能力,显示出巨大的价值和发展潜力,但现有研究对AI GIS软件技术体系的梳理和总结尚不够全面。大部分研究只关注地理空间人工智能算法的研究及其特定场景下的应用研究,而对相关的AI GIS软件技术体系关注较少。本文分析了地理智慧的几个层次,并讨论了其与AI GIS的关系,总体介绍了国内外现有人工智能技术与GIS软件相结合的发展现状,进而提出了AI GIS软件技术体系。根据AI与GIS的结合关系提出了AI GIS由地理空间智能算法、AI赋能GIS和GIS赋能AI三部分组成。此外,为深入介绍AI GIS各部分组成,本文以SuperMap为例,探讨了AI GIS软件的设计与实现。最后,探讨了AI GIS的未来发展中亟需解决的问题。本文基于AI GIS软件技术的初步探索,尝试为地理智能的基础GIS软件技术体系的构建提供理论基础,以促进人工智能技术与GIS技术的进一步融合和发展,为实现地理智能提供一个可行的研究方向。     

人造地震动合成中的位移误差分析

三角函数级数法是合成人工地震动常用算法之一,但是通过对加速度积分求取位移时,却存在与零线漂移相类似的位移漂移现象。     

一种园林火灾智能检测与定位系统的基本方案研究

介绍了红外检测传感器的检测原理；基于模糊理论，研究了传感器检测信息的处理方法；提出了用系流气球平台代替园林火灾观测嘹望台，应用GPS与红外检测器结合来实现园林火灾的自动监测和定位；建立了园林火灾智能监测系统设计框架。     

Experimental and theoretical investigations of drainage in horizontal rough-walled fractures with different correlation structures

Experiments on the immiscible displacement of water by air were performed in two horizontal artificial open rough-walled fractures with different correlation structures. The aperture field of the first fracture has a Gaussian variogram with a finite correlation length, while that of the second one has a power-law variogram, for which no finite correlation length can be assigned. We simulated the displacement process using an invasion percolation model, which takes the in-plane curvature of the interface between water and air into account. The correlation structure of the aperture field has no effect on the irregularity of the shape of the air clusters. However, the correlation structure in combination with the in-plane curvature influences the density of the air clusters and thus has an impact on characteristic properties of the flow. We analyze the model parameters and properties with respect to the fracture properties. The stochastic average of the air clusters for models with different curvature numbers and fields with different correlation lengths is then calculated in order to analyze their influence on continuum approach models.     

遗传神经网络测井解释技术在宝北区块的应用初探

将遗传算法与人工神经网络(BP网络)的原理结合,对BP网络进行了改进,提高了收敛速度,并防止陷入局部极小。应用改进后的BP算法,建立了针对测井解释的神经网络模型,并应用此模型定量计算了宝北区块的多口井的渗透率值,其解释结果及精度均令人满意。