Multi-scale object-based measurement of arid plant community structure

The measurement of plant community structure provides an extensive understanding of its function, succession and ecological process. The detection of plant community boundary is rather a challenge despite in situ work. Recent advances in object-based image analysis (OBIA) and machine learning algorithms offer new opportunities to address this challenge. This study presents a multi-scale segmentation approach to accurately identify the boundaries of each vegetation and plant community for mapping plant community structure. Initially, a very high resolution (VHR) Worldview-2 image of a desert area is hierarchically segmented from scale parameter 2 to 500. Afterward, the peak values of the standard deviation of brightness and normalized difference vegetation index (NDVI) across the segmentation scales are detected to determine the optimal segmentation scales of homogeneous single plant and plant community boundaries. A multi-scale classification of vegetation characterization with features of multiple bands, NDVI, grey-level co-occurrence matrix (GLCM) entropy and shape index is performed to identify dryland vegetation types. Finally, the four vegetation structural features on the type, diversity, object size and shape are calculated within the plant community boundaries and composed to plant community structure categories. Comparing the results with the object fitting index (FI) of the reference data, the validation indicates that the optimal segmentations of tree, shrub and plant communities are consistent with the identified peak values.     

Externalizing cognitive maps via map reconstruction and verbal description

Universal Access in the Information Society - Helping blind people to build cognitive maps of an environment is one of the aims of several assistive systems. In order to evaluate such assistive...     

Evolutionary level set method for structural topology optimization

This paper proposes an evolutionary accelerated computational level set algorithm for structure topology optimization. It integrates the merits of evolutionary structure optimization (ESO) and level set method (LSM). Traditional LSM algorithm is largely dependent on the initial guess topology. The proposed method combines the merits of ESO techniques with those of LSM algorithm, while allowing new holes to be automatically generated in low strain energy within the nodal neighboring region during optimization. The validity and robustness of the new algorithm are supported by some widely used benchmark examples in topology optimization. Numerical computations show that optimization convergence is accelerated effectively.     

略论盐城“水利梦”

认真学习领会习近平总书记提出的"中国梦",结合实际,论述了如何转化为干好盐城水利工作的动力,见诸行动,出实策、鼓实劲、办实事,力争实现盐城的"水安全梦"、"水资源梦"、"水环境梦"、"水生态梦"、"水经济梦"和"水文化梦",同心践行和助力"中国梦",真正实现人水相依、和谐共生、良性循环、全面繁荣。     

中型山区河流水电站下游的鱼类生态需水量计算

为更好地对河流水电开发后的鱼类进行保护,探讨中型山区河流水电站下游的鱼类生态需水量计算.参照大型河流鱼类水力生境参数标准,根据中型山区河流的特点,得到中型山区河流鱼类水力生境参数的参考标准.选取有代表性的四川中型山区河流杂谷脑河进行鱼类生境原型观测,原型观测结果证实了该参考标准能够满足杂谷脑河鱼类对生境的实际需求.基于所得到的参考标准,应用生态水力学法对杂谷脑河红叶二级、理县以及甘堡3座电站减水河段的鱼类生态需水量进行计算分析,得到3座电站的生态需水量推荐值.通过分析可知,所得到的生态需水量推荐值占年均天然流量以及设计引用流量的比例都不高,在3座电站的运行实践中,具有可操作性.     

Node trust evaluation in mobile ad hoc networks based on multi-dimensional fuzzy and Markov SCGM(1, 1) model

Due to the nature of distribution and self-organization, mobile ad hoc networks rely on cooperation between nodes to transfer information. One of the key factors to ensure high communication quality is an efficient assessment scheme for risks and trust of choosing next potential cooperative nodes. Trust model, an abstract psychological cognitive process, is one of the most complex concepts in social relationships, involving factors such as assumptions, expectations and behaviors. All of the above make it difficult to quantify and forecast trust accurately. In this paper, based on the theories of fuzzy recognition with feedback, SCGM(1, 1) model and Markov chain, we present a pattern of prediction making. The analysis and experimental computation show that this scheme is efficient in trust prediction for ad hoc networks.     

Buckling of carbon fiber composite pyramidal truss core sandwich columns

This paper deals with the theoretical prediction of global buckling loads for carbon fiber composite pyramidal truss core sandwich columns. Different from thin plate structures, transverse shear effect can not be neglected for sandwich structures. In addition, the attributes of the laminated face sheets are considered in the present paper. A zig-zag displacement approximation is made. Based on the principle of minimum potential energy, equilibrium equations and boundary conditions are derived via the variational method. The critical buckling loads under various boundary conditions are presented. In order to validate the reasonableness of the equivalent-core method, the strain energies stored in the actual discrete truss members and the equivalent continuous homogenous core layer are calculated respectively and compared, and a good agreement is obtained. The proposed analytical method is verified by comparing with the published theoretical predictions and experimental results.     

基于消除地方高校成长上限基模的实证研究——以江西M学校为例

本文基于系统动力学反馈基模分析方法,在分析江西地方高校发展的成长上限基模和对策基模的基础上进行实证研究,引入相关数据,构建消除成长上限基模的顶点赋权模型,并提出综合对策思考。     

对应用投资项目财务评价指标的探讨

投资项目财务效果评价指标，按决策目的可分为绝对效果评价指标和相对效果评价指标两大类；按是否考虑资金时间价值可分为静态评价指标和动态评价指标两大类。本文将按后一种分类对项目评价中使用的各种指标的应用作以下的探讨。