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Online Learning Approaches in Maximizing Weighted Throughput in an Unreliable Channel

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Tsinghua Science and Technology 2012年第5期17卷 567-574页

作者： zhi zhang Fei li Department of Computer Science George Mason University Fairfax VA 22030 USA

We design online algorithms to schedule unit-length packets with values and deadlines through an unreliable communication channel. In this model, time is discrete. Packets arrive over time; each packet has a non-negative value and an integer deadline. In each time step, at most one packet can be sent. The ratio of successfully delivering a packet depends on the channel＇s quality of reliability. The objective is to maximize the total value gained by delivering packets no later than their respective deadlines. In this paper, we conduct theoretical and empirical studies of online learning approaches for this model and a few of its variants. These online learning algorithms are analyzed in terms of external regret. We conclude that no online learning algorithms have constant regrets. Our online learning algorithms outperform online competitive algorithms in terms of algorithmic simplicity and running complexity. In general, these online learning algorithms work no worse than the best known competitive online algorithm for maximizing weighted throughput in practice.

关键词： online learning algorithm unreliable communication channel competitive online algorithm

S1280 and S1284: Two Oscillating Blue Stragglers in the Open Cluster M67

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Chinese Journal of Astronomy and Astrophysics 2005年第6期5卷 579-586页

作者： Xiao-Bin zhang Rong-Xian zhang zhi-Ping li National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

We present results of a time-series CCD photometry of two blue stragglers in the open cluster M67 that are also oscillating variables, S1280 and S1284. The observations obtained on 11 nights confirmed the δ Scuti-like variability of the two stars. Four and five main pulsating frequencies are detected for S1280 and S1284, respectively, through a power spectral analysis. A preliminary mode identification indicates that the two stars are both in radial oscillation. Based on the nature of oscillation, the physical parameters of the two stars are determined, and their evolutionary status discussed.

关键词： blue straggler - open cluster individual (M67) - stars oscillation - stars individual (S1280, S1284)

Regioselective Deprotection of 1,3-Dibenzyl-5-(N,N-dimethylamino)-6-phenylethyluracil

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Chemical Research in Chinese Universities 2008年第6期24卷 735-738页

作者： li A-min WANG Xiao-wei zhang zhi-li CHENG zhi-jian liU Jun-yi Department of Chemical Biology State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical Sciences Peking University Beijing 100083 P R. China Department of Chemistry College of Jiujiang Jiujiang 33200 P R. China

The deprotection of 1,3-dibenzyl-5-（N,N-dimethylamino）-6-phenyl-ethyluracil I was investigated. A practical, regioselective N3 deprotection of compound I was performed with excellent yield using cyclohexene as a hyd... 详细信息

关键词： 1,3-Dibenzyl-5-(N,N-dimethylamino)-6-phenylethyluracil Benzylprotecting Deprotection

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高分子材料SH改性夯土水敏性试验

兰州大学学报(自然科学版) 2025年第1期61卷 118-124,128页

作者：孔祥超和法国周瑾陆腾飞张理智吕雪梦兰州大学土木工程与力学学院西部灾害与环境力学教育部重点实验室兰州730000 中水北方勘测设计研究有限责任公司天津300000

为研究SH材料对夯土水敏性的影响,对压实度为88%、93%、99%的夯土,选取w(SH)为0、0.2%、0.4%、0.6%、0.8%五个梯度进行龄期、声波、渗透、吸水及崩解试验;利用扫描电子显微镜观察不同压实度及w(SH)试样的微观结构,对试验结果进行辅助分... 详细信息

为研究SH材料对夯土水敏性的影响,对压实度为88%、93%、99%的夯土,选取w(SH)为0、0.2%、0.4%、0.6%、0.8%五个梯度进行龄期、声波、渗透、吸水及崩解试验;利用扫描电子显微镜观察不同压实度及w(SH)试样的微观结构,对试验结果进行辅助分析.结果表明,试样28 d内已基本结束水分蒸发并完成内部结构增强;SH材料对低压实度试样的抗渗能力提高效果更显著;不同压实度及w(SH)试样的渗透系数与纵波波速之间相关性良好;相比压实度,在抑制夯土水敏性方面SH材料表现出更优的效果;当w(SH)≥0.4%,压实度≥93%时,试样水敏性明显减弱;SH材料通过填塞内部孔隙、增强颗粒联结及疏水基团斥水作用有效改善了夯土水敏性.

关键词：夯土 SH材料压实度纵波波速水敏性扫描电子显微镜

Triterpene Acids from Cynoglossum amabile

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Chemical Research in Chinese Universities 2009年第3期25卷 404-406页

作者： XU Qing-jun zhang De-zhi DANG li-juan li Kun-ping College of Pharmacy Guangdong Pharmaceutical University Guangzhou 510006 P. R. China

Cynoglossum amabile Stapf et Drumm is widely distributed in southern China, which has been used as an anti-inflammatory, antihepatitis, anticystitis agent in Chinese folk medicine. However, only a few phytochemical researches have been performed . Therefore, a systematic chemical investigation of it was carried out. In this work, we further investigated the chemical constituents and ten compounds were obtained, three of which were triterpene acids.

关键词： Cynoglossum amabile Triterpene acid Amabilic acid

Development of a monolithic polymer pipette for solid-phase extraction of liquiritigenin in rat plasma

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Chinese Chemical Letters 2012年第6期23卷 723-726页

作者： Hong Wu zhang Kang li zhi Xian liang Feng YangWang Qi Wen Lu School of Pharmacy Guangdong Pharmaceutical College Guangzhou 510006 China

A monolithic polymer column with mixed-mode interaction was prepared by in situ polymerization in a 1000μL pipette. Two kinds of monomers, butyl methacrylate （BMA） and 2-（dimethylamino）ethyl methacrylate （DMAM） were applied to constructing the mixed-mode interaction of monolithic polymer column. Its solid-phase extraction properties for liquiritigenin （LQG） were evaluated by high performance liquid chromatography （HPLC） with a gradient elution procedure. After the extraction procedure was optimized, the maximum binding capacity and extraction recovery following the optimal extraction procedure were investigated. Calibration curve was expressed as A = 65.9C ＋ 4.53 （r2 = 0.998） with a linear range of 0.151-1.80μg/mL. The experimental results indicate that the monolithic polymer pipette presents good extraction efficiency for LQG. It can be envisaged that the developed monolithic polymer pipette possesses the potential for its application to the enrichment of other flavonoids compounds being similar to the structure of LQG.

关键词： Monolithic polymer pipette Solid phase extraction High performance liquid chromatography liquiritigenin

Deep hybrid: Multi-graph neural network collaboration for hyperspectral image classification

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Defence Technology（防务技术） 2023年第5期23卷 164-176页

作者： Ding Yao zhang zhi-li Zhao Xiao-feng Cai Wei He Fang Cai Yao-ming Wei-Wei Cai Xi'an Research Institute of High Technology Xi'an710025China The School of Computer Science China University of GeosciencesWuhan430074China The School of Artificial Intelligence and Computer Science Jiangnan UniversityWuxi214122China

With limited number of labeled samples,hyperspectral image(HSI)classification is a difficult Problem in current *** graph neural network(GNN)has emerged as an approach to semi-supervised classification,and the application of GNN to hyperspectral images has attracted much ***,in the existing GNN-based methods a single graph neural network or graph filter is mainly used to extract HSI features,which does not take full advantage of various graph neural networks(graph filters).Moreover,the traditional GNNs have the problem of *** alleviate these shortcomings,we introduce a deep hybrid multi-graph neural network(DHMG),where two different graph filters,i.e.,the spectral filter and the autoregressive moving average(ARMA)filter,are utilized in two *** former can well extract the spectral features of the nodes,and the latter has a good suppression effect on graph *** network realizes information interaction between the two branches and takes good advantage of different graph *** addition,to address the problem of oversmoothing,a dense network is proposed,where the local graph features are *** dense structure satisfies the needs of different classification targets presenting different ***,we introduce a GraphSAGEbased network to refine the graph features produced by the deep hybrid *** experiments on three public HSI datasets strongly demonstrate that the DHMG dramatically outperforms the state-ofthe-art models.

关键词： Graph neural network Hyperspectral image classification Deep hybrid network

Fingerprinting Analysis of Rhizoma Chuanxiong of Commercial Types using ~1H Nuclear Magnetic Resonance Spectroscopy and High Performance liquid Chromatography Method

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Journal of Integrative Plant Biology 2009年第6期51卷 537-544页

作者： Hai-lin Qin An-Jun Deng Guan-Hua Du Peng Wang Jin-Lan zhang zhi-Hong li Institute of Materia Medica Chinese Academy of Medical Sciences Peking Union Medical College Key Laboratory of Bioactive Substances and Resources of Chinese Herbal Medicine Ministry of Education Beijing 100050 China

The ^1 H nuclear magnetic resonance （^1 H NMR） fingerprints of fractionated non-polar extracts （control substance for a plant drug （CSPD） A） from Rhizoma chuanxiong, the rhizomes of ligusticum chuanxiong Hort., of seven specimens from different sources were measured on Fourier Transform （FT）-NMR spectrometer and assigned by comparing them with the ^1 H NMR spectra of the isolated pure compounds. The ^1 H NMR fingerprints showed exclusively characteristic resonance signals of the major special constituents of the plant. Although the differences in the relative intensity of the ^1H NMR signals due to a discrepancy in the ratio of the major constituents among these samples could be confirmed by high performance liquid chromatography analysis, the general features of the ^1H NMR fingerprint established for an authentic sample of the rhizomes of L. chuanxiong e. hibited exclusive data from those special compounds and can be used for authenticating L. Chuanxiong species.

关键词： control substance for a plant drug A ^1 H nuclear magnetic resonance fingerprint high performance liquid chromatography ligusticumchuanxiong phenylpropenoid phthalides.

Image-based Virtual Exhibit and Its Extension to 3D

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International Journal of Automation and computing 2007年第1期4卷 18-24页

作者： Ming-Min zhang zhi-Geng Pan li-Feng Ren Peng Wang State Key Laboratory of CAD＆CG Zhejiang University Hangzhou 310027 PRC

In this paper we introduce an image-based virtual exhibition system especially for clothing product. It can provide a powerful material substitution function, which is very useful for customization clothing-built. A novel color substitution algorithm and two texture morphing methods are designed to ensure realistic substitution result. To extend it to 3D, we need to do the model reconstruction based on photos. Thus we present an improved method for modeling human body. It deforms a generic model with shape details extracted from pictures to generate a new model. Our method begins with model image generation followed by silhouette extraction and segmentation. Then it builds a mapping between pixels inside every pair of silhouette segments in the model image and in the picture. Our mapping algorithm is based on a slice space representation that conforms to the natural features of human body.

关键词： Virtual exhibition color substitution texture morphing reflection component decomposition virtual reality.