Surface tension calculation of the Sn–Ga–In ternary alloy

Surface tensions of the Sn–Ga–In ternary alloy are calculated from the surface tensions of the Sn–Ga, Ga–In and In–Sn sub-binary systems by using geometric models (the Kohler model and the Toop model), and a general solution model (the Chou model). The calculated results are in excellent agreement with the experimental data (except for the Kohler model), assuming an experimental accuracy of ±2.5%. At the same time, the surface tensions of the Sn–Ga–In ternary alloy at 773 K and their sub-binary systems are predicted on the basis of Butler’s equation, in combination with thermodynamic data, and different model parameters β$\beta$ equal to the ratio of the coordination number in the surface phase to that in the bulk phase. Different values of β$\beta$ have almost no influence on the surface tensions. The predicted results agree with the experimental data. Therefore, the resulting iso-surface tension curves for the Sn–Ga–In ternary alloy at 773 K, especially those calculated by using the Toop model, are reasonable.     

An Algorithm for Timing Verification of Systems Constrained by Min–max Inequalities

To determine the maximum separation between events for nonrepetitive systems with max and linear constraints, there are the “iterative tightening from above” (ITA) approach and the “iterative tightening from below” (ITB) approach. Since such systems can be formulated as systems constrained by min–max inequalities, this paper gives an algorithm named MMIMaxSep for solving min–max inequalities. The algorithm is a generalization and a mathematically elegant reformulation of Yen et al.’s MaxSeparation algorithm which uses the ITB approach. Our numerical experiments indicate that MMIMaxSep is very efficient. Moreover, MMIMaxSep has a unique advantage of being able to directly handle tree-represented min–max functions, and its complexity is closely related to the complexity of computing cycle time of min–max functions.

An image rectification scheme and its applications in RST invariant digital image watermarking

This paper presents an image rectification scheme that can be used by any image watermarking algorithm to provide robustness against rotation, scaling and translation (RST) transformations. Rotation and scaling transformations in the spatial domain result in cyclically translational shifts in the log-polar mapping (LPM) of the magnitude of the Fourier transform spectrum of an image. We cut a small block from the LPM domain as a matching template. A new filtering method is proposed to compute the cross-correlation between this template and the magnitude of the LPM of the image having undergone RST transformations to detect the rotation and scaling parameters. We employ the same strategy in the spatial domain to detect the translational parameters in the spatial domain. The scheme can also be used to detect image flipping. The cost of the templates is low and the templates can even be compressed. The detection accuracy for rotation, scaling and translation is also presented. We compare the matching results for the different filters and their performance by the three criteria: signal-to-noise ratio (SNR), peak-to-correlation energy (PCE), and Horner efficiency. We demonstrate that our phase-only filtering method is the only one that can be used in the LPM domain. We also introduce three applications for this rectification scheme and give their experimental results.

Restoring warped document images through 3D shape modeling

Scanning a document page from a thick bound volume often results in two kinds of distortions in the scanned image, i.e., shade along the "spine" of the book and warping in the shade area. In this paper, we propose an efficient restoration method based on the discovery of the 3D shape of a book surface from the shading information in a scanned document image. From a technical point of view, this shape from shading (SFS) problem in real-world environments is characterized by 1) a proximal and moving light source, 2) Lambertian reflection, 3) nonuniform albedo distribution, and 4) document skew. Taking all these factors into account, we first build practical models (consisting of a 3D geometric model and a 3D optical model) for the practical scanning conditions to reconstruct the 3D shape of the book surface. We next restore the scanned document image using this shape based on deshading and dewarping models. Finally, we evaluate the restoration results by comparing our estimated surface shape with the real shape as well as the OCR performance on original and restored document images. The results show that the geometric and photometric distortions are mostly removed and the OCR results are improved markedly.     

Meta-heuristic algorithms for parameter estimation of semi-parametric linear regression models

Consider the semi-parametric linear regression model Y=β^′X+ε, where ε has an unknown distribution F₀. The semi-parametric MLE of β under this set-up is called the generalized semi-parametric MLE(GSMLE). Although the GSML estimation of the linear regression model is statistically appealing, it has never been attempted due to difficulties with obtaining the GSML estimates of β and F until recent work on linear regression for complete data and for right-censored data by Yu and Wong [2003a. Asymptotic properties of the generalized semi-parametric MLE in linear regression. Statistica Sinica 13, 311-326; 2003b. Semi-parametric MLE in simple linear regression analysis with interval-censored data. Commun. Statist.—Simulation Comput. 32, 147-164; 2003c. The semi-parametric MLE in linear regression with right censored data. J. Statist. Comput. Simul. 73, 833-848]. However, after obtaining all candidates, their algorithm simply does an exhaustive search to find the GSML estimators. In this paper, it is shown that Yu and Wong's algorithm leads to the so-called dimension disaster. Based on their idea, a simulated annealing algorithm for finding semi-parametric MLE is proposed along with techniques to reduce computations. Experimental results show that the new algorithm runs much faster for multiple linear regression models while keeping the nice features of Yu and Wong's original one.     

基于阶跃响应的非自衡对象预测控制

针对现有非自衡对象DMC算法预测模型不易建立的局限性,提出一种基于非自衡对象阶跃响应的DMC算法。分析与仿真结果表明,该算法对于设定值变化和输入扰动均无控制余差,且预测模型易于建立。     

稳健二进神经网络的几何训练

在二进神经网络的规划划分训练方法基础上,针对稳键二进神经网络稳健神经元的特点,讨论了稳健分类超平面的几何构造方法,并提出了相应的训练算法,包括隐层神经元的几何训练和输出神经无的进化训练。实验表明,该算法对复杂Boole函数的稳健二进神经网络的实现是有效且可行的。     

（RbCl）108离子簇均相成核的分子动力学研究

分子动力学模拟测得熔融（RbCl)108离子簇在300K至600K温度时凝固的成核速率大于10^35m^-3s^-1,用均相成核的经典理论加以分析,估算得氯化铷离子簇的固液界面自由能σalT^1.4,用Grunasy提出的扩散界面理论加以分析,估算得扩展界面厚度约为0．195nm,σalT^0.97,2个理论在实验温度范围内没有明显判别,且均能较好地分子动力学模型的结果,但预测的较高温度下的成核速率有比较显著区别,因此进一步地研究将有助于鉴别它们。     

智能化仪表实现微小量检测的两个软件措施

提出了多点平均和展宽频带的算法。利用计算机的数据存储器作为数字式多点平均器的存储器,用于检测完全被噪声遮蔽的信号。当模拟-数字转换（ADC）器件采样频率一定时,采用展宽频带的方法可以实现对高频和很低频率信号的实时处理,从而提高了仪表的精度,增加了它的动态工作范围。     

Kosha: A Peer-to-Peer Enhancement for the Network File System

The storage needs of modern scientific applications are growing exponentially, and designing economical storage solutions for such applications – especially in Grid environments – is an important research topic. This work presents Kosha, a system that aims to harvest redundant storage space on cluster nodes and user desktops to provide a reliable, shared file system that acts as a large distributed storage. Kosha utilizes peer-to-peer (p2p) mechanisms to enhance the widely-used Network File System (NFS). P2P storage systems provide location transparency, mobility transparency, load balancing, and file replication – features that are not available in NFS. On the other hand, NFS provides hierarchical file organization, directory listings, and file permissions, which are missing from p2p storage systems. By blending the strengths of NFS and p2p storage systems, Kosha provides a low overhead storage solution. Our experiments show that compared to unmodified NFS, Kosha introduces a 3.3% fixed overhead and 4.5% additional overhead as nodes are increased from two to sixteen. For larger number of nodes, the additional overhead increases slowly. Kosha achieves load balancing in distributed directories, and guarantees or better file availability.*This work was supported in part by an NSF CAREER award (ACI-0238379).Troy A. Johnson was supported by a U.S. Department of Education GAANN doctoral fellowship.