Efficient Nonnegative Matrix Factorization via projected Newton method

Nonnegative Matrix Factorization (NMF) is a popular decomposition technique in pattern analysis, document clustering, image processing and related fields. In this paper, we propose a fast NMF algorithm via Projected Newton Method (PNM). First, we propose PNM to efficiently solve a nonnegative least squares problem, which achieves a quadratic convergence rate under appropriate assumptions. Second, in the framework of an alternating optimization method, we adopt PNM as an essential subroutine to efficiently solve the NMF problem. Moreover, by exploiting the low rank assumption of NMF, we make PNM very suitable for solving NMF efficiently. Empirical studies on both synthetic and real-world (text and image) data demonstrate that PNM is quite efficient to solve NMF compared with several state of the art algorithms.     

Automatic Real-Time Video Matting Using Time-of-Flight Camera and Multichannel Poisson Equations

This paper presents an automatic real-time video matting system. The proposed system consists of two novel components. In order to automatically generate trimaps for live videos, we advocate a Time-of-Flight (TOF) camera-based approach to video bilayer segmentation. Our algorithm combines color and depth cues in a probabilistic fusion framework. The scene depth information returned by the TOF camera is less sensitive to environment changes, which makes our method robust to illumination variation, dynamic background and camera motion. For the second step, we perform alpha matting based on the segmentation result. Our matting algorithm uses a set of novel Poisson equations that are derived for handling multichannel color vectors, as well as the depth information captured. Real-time processing speed is achieved through optimizing the algorithm for parallel processing on graphics hardware. We demonstrate the effectiveness of our matting system on an extensive set of experimental results.     

Service-oriented architecture for ontologies supporting multi-agent system negotiations in virtual enterprise

This paper offers a service-oriented architecture (SOA) for ontology-based multi-agent system (MAS) negotiations in the context of virtual enterprises (VEs). The objective of this paper is fourfold. First, it is to design a SOA which utilizes ontology and MAS to provide a distributed and interoperable environment for automated negotiations in VE. In this architecture, individual ontologies for both the VE initiator and its potential partners are constructed to describe and store resources and service knowledge. Second, a series of semantic ontology matching methods are developed to reach agents’ interoperability during the negotiation process. Third, correspondence-based extended contract net protocol is presented, which provides basic guidelines for agents’ reaching mutual understandings and service negotiation. Last, a fuzzy set theory based knowledge reuse approach is proposed to evaluate the current negotiation behaviors of the VE partners. A walkthrough example is presented to illustrate the methodologies and system architecture proposed in this paper.     

砂土的剪胀方程及其塑性势(Ⅰ):发展现状

以能量守恒原理为主线,在各向同性前提下,对Taylor剪胀方程、Cam-clay剪胀方程、修正Cam-clay剪胀方程、Rowe剪胀方程和扩展的Rowe剪胀方程等进行了较全面的综述.论证了剪胀方程和塑性势函数之间的相互转化关系.指出了Lade-Kim塑性势函数和Nova塑性势函数的缺陷之处,即这两个塑性势函数均没有合理耦合临界状态这一概念.     

结合结构下文及词汇信息的汉语句法分析方法

针对句法分析中上下文无关语法模型对句子信息利用的不足,通过融入结构下文和部分词汇信息,提出两种基于概率上下文无关语法模型的短语结构消歧方法,以达到消解结构歧义的目的;引入分层分析的算法,通过损失一定的时间效率使得在提高分析准确率的同时保证分析结果的全面性。实验结果表明,融入结构下文及词汇信息的汉语句法分析方法,利用了更多的句子信息,与上下文无关语法相比有着更强的消歧能力。     

聚合物在离子选择电极上的应用

本文概述了聚合物膜离子选择电极的发展,制备、应用等方面的研究情况;将聚合物膜离子选择电极分为固态膜类和液态膜类,分别对其优缺点和发展前景加以分析;并讨论了聚合物在敏感膜中的作用,以及聚合物结构对敏感膜性能的可能影响。     

工业建设项目可研报告中市场预测的定性分析

众所周知，市场预测是投资项目可行性研究报告中一项非常重要的内容，是科学决策的主要依据。市场预测是对项目的产出品和所需的主要投入品的市场容量、价格、竞争力、营销策略以及市场风险进行分析预测。     

Effects of modified hyperbranched polyester as a curing agent on the morphology and properties of dynamically cured polypropylene/polyurethane blends

The dynamic vulcanization process, usually used for the preparation of thermoplastic elastomers, has been applied to prepare polypropylene (PP)/polyurethane (PU) blends. Boltorn^TM H20 (H20) hyperbranched polyester containing 16 hydroxyl end gropus and pentaerythritol are used as curing agents, respectively, for curing PU oligomer during blending with molten PP. To improve the compatibility of cured PU particles with PP matrix, H20 is partly functionalized with stearic acid. The morphology, mechanical properties, thermal properties and melt flow index (MFI) of the PP/PU blends with different curing agent are investigated. Compared with pentaerythritol, SEM photographs show that H20 partly functionalized with stearic acid effectively reduces the size and size distribution of cured PU particles in PP/PU blends which also is proved by MFI measurement. Consequently, the dynamically cured PP/PU blends with modified H20 have better mechanical properties than those cured with pentaerythritol. The shifts of crystallization peaks to higher temperatures for all PP/PU blends indicate that PU particles in the blends can act as effective nucleating agents. Moreover, due to the smaller size of PU particles PP/PU blends cured with modified H20 have higher crystallization temperatures than those blends cured with pentaerythritol at the same PU content.     

Wear behavior of low-pressure plasma-sprayed AlCuFe quasicrystalline coating on titanium alloy

The wear-resistant AlCuFe quasicrystalline coating was fabricated on substrate of titanium alloy by low-pressure plasma-spraying (LPPS) method. The LPPS AlCuFe quasicrystalline coating has a rapidly solidified lamellar microstructure consisting of mainly icosahedral phase and small amount of cubic phase peaks. The results showed that AlCuFe quasicrystalline coating improved the wear resistance of titanium-based alloys under dry sliding wear test conditions. The excellent wear resistance may be attributed to the high hardness of AlCuFe quasicrystal and the formation of the tribofilm.