Invasive species detection in Hawaiian rainforests using airborne imaging spectroscopy and LiDAR

Remote sensing of invasive species is a critical component of conservation and management efforts, but reliable methods for the detection of invaders have not been widely established. In Hawaiian forests, we recently found that invasive trees often have hyperspectral signatures unique from that of native trees, but mapping based on spectral reflectance properties alone is confounded by issues of canopy senescence and mortality, intra- and inter-canopy gaps and shadowing, and terrain variability. We deployed a new hybrid airborne system combining the Carnegie Airborne Observatory (CAO) small-footprint light detection and ranging (LiDAR) system with the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) to map the three-dimensional spectral and structural properties of Hawaiian forests. The CAO-AVIRIS systems and data were fully integrated using in-flight and post-flight fusion techniques, facilitating an analysis of forest canopy properties to determine the presence and abundance of three highly invasive tree species in Hawaiian rainforests.

The LiDAR sub-system was used to model forest canopy height and top-of-canopy surfaces; these structural data allowed for automated masking of forest gaps, intra- and inter-canopy shadows, and minimum vegetation height in the AVIRIS images. The remaining sunlit canopy spectra were analyzed using spatially-constrained spectral mixture analysis. The results of the combined LiDAR-spectroscopic analysis highlighted the location and fractional abundance of each invasive tree species throughout the rainforest sites. Field validation studies demonstrated < 6.8% and < 18.6% error rates in the detection of invasive tree species at  7 m² and  2 m² minimum canopy cover thresholds. Our results show that full integration of imaging spectroscopy and LiDAR measurements provides enormous flexibility and analytical potential for studies of terrestrial ecosystems and the species contained within them.     

基于区间箱粒子多伯努利滤波器的传感器控制策略

多目标跟踪中的传感器控制本质上是一个最优非线性控制问题, 其在理论分析和计算上极具挑战性. 本文基于区间不确定性推理, 利用箱粒子多伯努利滤波器提出了一种基于信息测度的传感器控制策略. 首先, 本文利用箱粒子实现多伯努利滤波器, 并通过一组带有权值的箱粒子来表征多目标后验概率密度函数. 其次, 利用箱粒子的高斯分布假设, 将多伯努利密度近似为高斯混合. 随后, 选择柯西施瓦兹(Cauchy-Schwarz, CS) 散度作为评价函数, 并详细推导了两个高斯混合之间的CS散度的求解公式, 以此为基础提出相应的传感器控制策略. 此外, 作为一种对比方案, 利用蒙特卡罗方法, 本文还给出了通过对箱粒子进行混合均匀采样, 进而通过点粒子求解CS散度的递推公式, 并提出了相应的控制策略. 最后, 仿真实验验证了所提算法的有效性.     

常州大剧院主体结构施工新技术应用

现代化、多功能的常州大剧院工程因其独特的设计、复杂的结构形式、新材料多、施工难度大、工期紧,通过严密的施工组织,合理的分区分块,精心的施工管理,应用多变复杂的测量控制,深基坑支护及降水,清水混凝土模板,特大型现浇钢筋桁架支撑技术,大型不规则形空间网架等,做到了技术先进,安全可靠。     

Removal mechanisms for endocrine disrupting compounds (EDCs) in wastewater treatment - physical means, biodegradation, and chemical advanced oxidation: a review

Endocrine disrupting compounds (EDCs) are pollutants with estrogenic or androgenic activity at very low concentrations and are emerging as a major concern for water quality. Within the past few decades, more and more target chemicals were monitored as the source of estrogenic or androgenic activity in wastewater, and great endeavors have been done on the removal of EDCs in wastewater. This article reviewed removal of EDCs from three aspects, that is, physical means, biodegradation, and chemical advanced oxidation (CAO).     

论曹魏前期文士创作的民歌化特征

建安文学风貌的形成,曹丕和围绕在他周围的文士起了异常重要的作用.在诗歌技术上,曹丕和这些文士都受到汉乐府的影响,形成了通俗白话的创作倾向,描述视角、语言运用等方面都形成了较为独特的风格.     

在AutoCAD中利用数据库技术建立基础地理信息库

介绍了在AutoCAD中如何利用连接自动化对象(CAO)技术和ADO数据库访问技术在城市数字地图上进行加工处理，实现属性数据与图形数据的无缝结合，进而建立满足GIS应用需求的城市道路网络基础地理信息库的过程。     

Design and measurements of a RF front-end for Bi-band simultaneous reception

In this paper, we explore spectrum field band simultaneous receivers, with a special emphasis on only one aspect of these systems – the radio front-end. We propose, to validate in the lab, a receiver scheme for the simultaneous down-conversion of two signals in different bands. Obviously, the dedicated scheme is intended for practical use in an integrated circuit. In this work, the chosen receiver is implemented with discrete components. A test set is evaluated and compared to simulations; it contains mostly standard lab equipment, processing signals, according to the receiver scheme; this receiver presents merits and it is worth demonstrating in an integrated circuit.In order to give credit to the use of this type of receiver, the EDA model and results have to be validated by measurement. Therefore, based on the receiver architecture dedicated to an 802.11/UMTS simultaneous dual-channel processing, we design and fabricate a prototype. Firstly, we measure the intrinsic metrics of this prototype in terms of noise figure, gain, linearity, phase and gain mismatch between the two branches of the quadrature mounted mixers. In the present work, we demonstrate that, for instance, as NF and IIP3 change with the RF front-end gain with the improvement of the RF front-end performance, the linearity and the noise requirements are well handled. Afterwards, these metrics are injected in the EDA receiver model and simulations are done in order to evaluate the BER evolution.     

CAO法处理化工废水技术的探讨

分析化工废水治理技术现状 ,介绍CAO法工艺流程 ,相关技术参数的选择试验及本技术处理废水的效果 ,得出该法处理化工废水技术各项指标优于国内现有技术 ,有推广潜力。     

CAO垃圾焚烧系统热力模型研究

将CAO垃圾焚烧系统的两个燃烧室划分为：加热干燥区（A）、热解气化区（B）、残碳燃烧区（C）、可燃气燃烧区（D）。用多孔介质有效导热系数法,建立了A、B区中垃圾升温的传热模型;用不规则孔隙网络法,建立了B、C区中碳的气化和燃烧反应模型;用均相动力控制反应模型,分析了D区中多种化合物燃烬规律。最后讨论了CAO系统稳定燃烧的规律。     

CAO技术在环氧乙烷装置中的应用

介绍了环氧乙烷装置中计算机辅助操作（CAO）技术的主要控制原理;概括了CAO技术的组成部分,包括质谱仪采样及计算、反应性能参数计算、闭环控制等;阐述了CAO对整个环氧乙烷装置的效益核算,包括提高乙烯的效率、延长装置在线时间、增强装置安全性等。通过CAO技术在环氧乙烷装置中的成功应用阐明了CAO技术的优点及可用性,对于同类装置有一定的借鉴。