Rotation invariant analysis and orientation estimation method for texture classification based on Radon transform and correlation analysis

Some recent rotation invariant texture analysis approaches such as multiresolution approaches yield high correct classification percentages, but present insufficient noise tolerance. This paper describes a new method for rotation invariant texture analysis. In the proposed method, Radon transform is utilized to project a texture image onto projection space to convert a rotation of the original texture image to a translation of the projection in the angle variable, and then Radon projection correlation distance is introduced. A k-nearest neighbors’ classifier with Radon projection correlation distances is employed to implement texture classification and orientation estimation. Theoretical and experimental results show the high classification accuracy of this approach as a result of using the Radon projection correlation distance instead of repetitious usage of discrete transforms. It is also shown that the proposed method presents high noise tolerance and yields high accuracy in orientation estimation in comparison with Khouzani’s method.     

HSDPA与R99/R4混合组网容量规划

对WCDMAR99/R4网络与HSDPA网络可提供的容量分别进行分析;根据HSDPA的技术特点,对HSPDA与R99/R4混合组网后提供的各类语音、数据业务做出容量规划。     

TOA-based robust location algorithms for wireless cellular networks

Caused by Non-Line-Of-Sight (NLOS) propagation effect, the non-symmetric contamination of measured Time Of Arrival (TOA) data leads to high inaccuracies of the conventional TOA based mobile location techniques. Robust position estimation method based on bootstrapping M-estimation and Huber estimator are proposed to mitigate the effects of NLOS propagation on the location error. Simulation results show the improvement over traditional Least-Square (LS) algorithm on location accuracy under different channel environments.     

基于两片TMS320F206芯片在遥测数据采集中的应用

为了适应再入遥测采集系统的要求,本文中主要采用两片高速DSP芯片TMS320F260和乒乓缓存技术设计的嵌入式高速采集系统,实现了对多数量、多种类被测参数的采集、存储、传输和处理,模块化设计以及大规模可编程逻辑器件的采用使系统具有较强的可编程性和可维护性。     

氟镓酸盐红外玻璃窗口多波段增透保护膜研制

氟镓酸盐玻璃是一种性能良好的红外光窗材料。为了提升窗口观测、探测及防护性能,在氟镓酸盐基底上设计和制备了0.4~0.9 μm、1.064 μm、3.7~4.8 μm三波段复合增透保护膜。根据光学性能及环境稳定性要求选择薄膜材料并对膜系进行了设计,然后利用电子束蒸发方法对多层膜进行了制备。测量结果表明,2.9 μm处的水吸收峰拉低了中红外波段的透过率。通过改进工艺及后处理等途径提高了膜层致密度,有效抑制了膜层的水吸收。利用沸水浸泡法对镀膜元件的环境稳定性进行了实验验证。结果表明,经过离子束辅助沉积及退火处理的薄膜样品具有较好的光学性能和环境适应性。     

基于PLC污水检测系统的设计与应用

提出一种基于PLC的远程污水智能监控系统的设计方法.通过传感器采集设备长时间监控污水的变化情况,运用无线网络技术实时传递污水现场的情况,针对传递中的信号存在大量噪声,提出信号去噪方案,结合污水监控系统的要求,给出了基于可编程控制器的污水监控控制系统的硬件结构设计以及各个部分的软件设计.该方案设计的系统能够有效的监控污水泄露并反馈信息,取得了令人满意的效果.     

卡塞格伦镜头的猫眼效应激光反射特性

卡塞格伦(Cassegrain)及类卡塞格伦式光学镜头在光电装备中应用广泛.为了研究具备卡塞格伦式光学镜头的光电装备所特有的猫眼效应特性,采用ZEMAX光学设计分析软件建立了卡塞格伦镜头反射模型,利用物理光学传输方法仿真分析了其猫眼效应反射特性,并得出了猫眼效应可探测入射角范围.对一特定卡塞格伦镜头进行了激光辐照实验,得到了猫眼效应反射光斑图像,测试了猫眼效应绝对反射率以及反射光发散角.结果表明,当发射系统位于该卡塞格伦镜头的视场内时,可以探测到猫眼效应反射光,中心遮挡造成原路返回处光强分布中心能量降低,猫眼效应绝对反射率为11.48%,反射光发散角为3.3 mrad,按照假设条件可以满足30 km内激光主动探测的需要.     

A 3D Hybrid of Chemically Coupled Nickel Sulfide and Hollow Carbon Spheres for High Performance Lithium–Sulfur Batteries

Lithium–sulfur batteries are a promising next‐generation energy storage device owing to their high theoretical capacity and the low cost and abundance of sulfur. However, the low conductivity and loss of active sulfur material during operation greatly limit the rating capabilities and cycling stability of lithium–sulfur batteries. In this work, a unique sulfur host hybrid material comprising nanosized nickel sulfide (NiS) uniformly distributed on 3D carbon hollow spheres (C‐HS) is fabricated using an in situ thermal reduction and sulfidation method. In the hybrid material, the nanosized NiS provides a high adsorption capability for polysulfides and the C‐HS serves as a physical confinement for polysulfides and also a 3D electron transfer pathway. Moreover, NiS has strong chemical coupling with the C‐HS, favoring fast charge transfer and redox kinetics of the sulfur electrode. With a sulfur loading of up to 2.3 mg cm^?2, the hybrid material‐based lithium–sulfur batteries offer a capacity decay as low as 0.013% per cycle and a capacity of 695 mA h g^?1 at 0.5 C after 300 cycles. This unique 3D hybrid material with strong chemical coupling provides a promising sulfur host for high performance lithium–sulfur batteries.     

A Novel Color Image Segmentation Approach Based on Neutrosophic Set and Modified Fuzzy c-Means

Color image segmentation is an important technique in image processing, pattern recognition and computer vision. Many segmentation algorithms have been proposed. However, it is still a complex task especially when there are noises in the images, which have not been studied in much detail. Neutrosophic set (NS) studies the origin, nature, and scope of neutralities. In this paper, we apply NS in the color image and define some new concepts. A directional α-mean operation is proposed to reduce the set indeterminacy. The fuzzy c-means clustering method is improved by integrating with NS and employed for the color image segmentation. The computation of membership and the clustering termination criterion are redefined accordingly. Moreover, a validity criterion is employed to determine the optimal clustering number. Numerical experiments serve to illustrate the effectiveness and reliability of the proposed approach. Experimental results demonstrate that our approach can segment color images automatically and effectively, produce good results as favorably compared to some existing algorithms. The optimal clustering number is determined automatically and no prior knowledge is required. Especially, it can segment both images with the simple and distinct objects and the images with complex and noisy objects, which is the most difficult task for color image segmentation.