Polar-Cartesian Hybrid Transforms: A novel 2D range scan registration algorithm

Registration of range scans is commonly required in many localization and mapping algorithms. In this paper, we introduce a novel approach called Polar-Cartesian Hybrid Transforms for pair-wise registration of range scans. The proposed algorithm iteratively establishes correspondences by searching the points with closest polar angles in the polar coordinate frame. An angular look-up table is constructed based on the properties of the laser range finder to accelerate the searching procedure. In order to speed up the convergence, we compute the difference of polar range of every matched point pair to select the most contributing correspondences. After the correspondences are determined, the transformation is computed in Cartesian coordinate frame using a point-to-line metric. Combining the advantages of the polar and Cartesian coordinate frames, both robustness and efficiency are greatly improved compared with an up-to-date ICP algorithm.     

Direct microscale imprinting of Al at room temperature with Si inserts

For direct imprinting of metals, hard materials such as diamond and SiC have been used to construct mold inserts in preference to Si, despite the ease in fabricating Si-based micro-/nano- scale structures. In this communication, we demonstrate that micron scale Al structures can be replicated with good fidelity at room temperature by compression molding with Si inserts without incurring insert damage. We further report on results of a finite element analysis of the mechanics of the molding process. The finite element results provide some understanding of the observed lack of damage to the Si inserts.     

遗传算法与文本特征选择方法相结合的研究

对文本特征选择的传统方法进行了深入分析并对各自的优缺点进行了详细的对比;其次,通过利用遗传算法自身的寻优特点,把它与传统特征选择方法相结合,并得出了算法。最后,在对各自算法进行了分析,表明了在性能上有了明显的提高。     

Ubiquitous Personal Study: a framework for supporting information access and sharing

The information resources on the Web are diversified, the amount of which is increasing rapidly. Demands for selecting useful information from the Internet, managing personal contents, and sharing contents under control have risen. In this study, we propose the Ubiquitous Personal Study, a framework of personalized virtual study to support accessing, managing, organizing, sharing and recommending information. In this paper, we focus on discussing the framework, and design and implementation issues on how to implement it with Web 2.0 mash-up technology and Open Source Software.     

禅之韵——试谈卫浴空间的意境营造

禅是一种心灵体验,禅意的营造需要主人积极的情感投入。卫浴间是现代居室的重要组成部分,也是现代人放松身体的重要场所.本文试从卫浴产品的选择、空间的布局以及装饰三个方面展开讨论,对禅风的现实意义进行了反思。     

AutoCAD的尺寸驱动技术的探讨

AutoCAD是一种人机交互的绘图软件,本身并不具备参数化绘图功能,更不具备尺寸驱动功能,但用户可以利用其所提供的强大的二次开发语言AutoLISP、VisualLISP、VBA开发完全个性化的、性能更为优越的、具有尺寸驱动功能的参数化绘图软件。     

Pitchfork bifurcation and flip-flop operation with a coupled nonlinear system

A ring cavity system consisting of two hybrid Michelson interferometers coupled together with feedback is constructed. This system shows spatial bifurcation and can be utilized as an all-optical flip-flop device. We demonstrate experimentally a flip-flop operation by use of only a positive pulse in this system.     

Preparation of PbTiO3 thin films using an alkoxide-alkanolamine sol-gel system

The stable range of PbTiO₃ sol and the processing conditions of uniform thin films were investigated using a solution of titanium isopropoxide, three kinds of alkanolamines (monoethanolamine, diethanolamine, triethanolamine), lead acetate trihydrate and isopropanol. Depending on the sol state with various alkanolamine/alkoxide molar ratios, diethanolamine (DEA) was very effective in preparing uniform and dense oxide films through room-temperature reaction, owing to its superior stability during the hydrolysis and condensation reaction. Perovskite PbTiO₃ thin films were obtained on oxidized silicon wafer above 550 °C and completely pure films were obtained at 650 °C using DEA as a complexing agent. The dielectric constant and loss tangent of these thin films fired at 650 °C for 30 min were found to be 240 and 0.01 at 1 kHz, respectively.     

Siamese transformer network-based similarity metric learning for cross-source remote sensing image retrieval

Neural Computing and Applications - As a fundamental technique for mining and analysis of remote sensing (RS) big data, content-based remote sensing image retrieval (CBRSIR) has received a lot of...