Gao J.,Peking University |
Lu J.,Remin University of China |
Wang T.,Peking University |
Yang D.,Peking University
Journal of Systems and Software | Year: 2010
The query rewriting plan generation over XML views has received wide attention recently. However, little work has been done on efficient evaluation of the query rewriting plans, which is not trivial since the plan may contain an exponential size of sub-plans. This paper investigates the reason for the potentially exponential number of sub-plans, and then proposes a new space-efficient form called ABCPlan (Plan with Automata Based Combinations) to equivalently represent the original query rewriting plan. ABCPlan contains a set of buckets containing suffix paths in the query tree and an automata to indicate the combination of the suffix paths from different buckets as valid query rewriting sub-plans. We also design an evaluation method called ABCScan, which constructs a unified evaluation tree for the ABCPlan and handles the evaluation tree in one scan of the XML view. In the evaluation, we introduce node existence automata to encode the structure of the sub-tree and convert the satisfaction of the ABCPlan into the intersection problem of deterministic finite automata. The experiments show that ABCPlan based method outperforms existing methods significantly in terms of scalability and efficiency. © 2009 Elsevier Inc. All rights reserved.
Liu Q.,Remin University of China |
Liu Q.,Peking University |
Zhou Y.,Remin University of China |
Chen L.,University of Alberta |
Zheng X.,Remin University of China
Desalination | Year: 2010
In China, the number of hospitals has increased to 19,712 in 2008, with the production of hospital wastewater reaching 1.29 × 106 m3/d. Membrane bioreactor (MBR) technology presents a more efficient system at removing pathological microorganism compared with existing wastewater treatment systems. In the past 8 yr, over 50 MBR plants have been successfully built for hospital wastewater treatments, with the capacity ranging from 20 to 2000 m3/d. MBR can effectively save disinfectant consumption (chlorine addition can decrease to 1.0 mg/L), shorten the reaction time (approximately 1.5 min, 2.5-5% of conventional wastewater treatment process), and attain a good effect of inactivation of microorganism. Higher disinfection efficacy is achieved in MBR effluents at lower dose of disinfectant with less disinfection by-products (DBPs). Moreover, when capacity of MBR plants increases from 20 to 1000 m3/d, their operating cost decreases sharply. Crown Copyright © 2009.
A systematic review and meta-analysis of the prevalence, trends, and geographical distribution of HIV among Chinese female sex workers (2000-2011): implications for preventing sexually transmitted HIV
PubMed | Tsinghua University, University of New South Wales, University of North Carolina at Chapel Hill, Remin University of China and London School of Hygiene and Tropical Medicine
Type: | Journal: International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases | Year: 2015
The aim of this meta-analysis was to investigate temporal and geographical trends in the HIV epidemic among female sex workers (FSWs) recruited from various venues in China.Chinese and English peer-reviewed articles published between January 2000 and February 2013 were systematically searched. Standard meta-analysis methods were used to calculate the pooled HIV prevalence, in accordance with the PRISMA guidelines.The national HIV prevalence among FSWs declined from 0.74% (95% confidence interval (CI) 0.37-1.49%) in 2000-2002 to 0.40% (95% CI 0.31-0.53%) in 2009-2011. All Chinese regions demonstrated significant declines in HIV prevalence, apart from the East and South Central regions, in which the epidemics stabilized at low/moderate levels. Despite a significant decline from 1.92% (95% CI 0.86-4.24%) to 0.87% (95% CI 0.65-1.18%) during 2000-2011, Southwest China still bore the greatest HIV disease burden. Nationwide, FSWs recruited from detention centres had the highest HIV prevalence (0.92%, 95% CI 0.46-1.88%), followed by voluntary counselling and testing sites (0.80%, 95% CI 0.46-1.67%) and entertainment venues (0.61%, 95% CI 0.47-0.79%). The prevalences among FSWs in high-, middle-, and low-tier entertainment venues were 0.59% (95% CI 0.32-1.45%), 0.92% (95% CI 0.50-1.77%), and 1.10% (95% CI 0.71-2.16%), respectively. High- and middle-tier FSWs had a significantly lower risk of HIV infection than lower-tier FSWs (high/low: odds ratio (OR) 0.48, 95% CI 0.40-0.59; middle/low: OR 0.49, 95% CI 0.37-0.66).The HIV epidemic has shown a gradual declining or stabilizing trend among Chinese FSWs. Intervention efforts should be diverted to high-risk subgroups of FSWs, such as drug-using and low-tier FSWs.
PubMed | Tsinghua University, University of New South Wales, University of North Carolina at Chapel Hill and Remin University of China
Type: Journal Article | Journal: PloS one | Year: 2015
Commercial sex is one of the major modes of HIV transmission in China. Understanding HIV risk behaviours in female sex workers (FSW) is of great importance for prevention. This study aims to assess the magnitude and temporal changes of risk behaviours in Chinese FSW.Five electronic databases were searched to identify peer-reviewed English and Chinese language articles published between January 2000 and December 2012 that reported risk behaviours among FSW in China, including condom use, HIV testing, and drug use. Linear regression and Spearmans rank correlation were used to examine temporal trends in these risk factors. The study followed PRISMA guidelines for meta-analyses and was registered in the PROSPERO database for systematic reviews.A total of 583 articles (44 English, 539 Chinese) investigating 594,583 Chinese FSW were included in this review. At last sex, condom use was highest with commercial partners (clients), increasing from 53.7% in 2000 to 84.9% in 2011. During this same time period, condom use increased with regular partners from 15.2% to 40.4% and with unspecified partners from 38.6% to 82.5%. Increasing trends were also found in the proportion of sampled FSW who reported testing for HIV in the past 12 months (from 3.2% in 2000 to 48.0% in 2011), while drug use behaviours decreased significantly from 10.9% to 2.6%.During the first decade of 2000, Chinese FSWs self-reported risk behaviours have decreased significantly while HIV testing has increased. Further outreach and intervention efforts are needed to encourage condom use with regular partners, continue promotion of HIV testing, and provide resources for the most vulnerable FSW, particularly low tier FSW, who may have limited access to sexual health and prevention programs.
Gui B.,Remin University of China |
Yang X.,Huaiyin Normal University
Lecture Notes in Electrical Engineering | Year: 2014
The affinity propagation clustering is a new clustering algorithm. The volatility is introduced to measure the degree of the numerical oscillations. The research focuses on two main parameters of affinity propagation: preference and damping factor, and considers their relation with the numerical oscillating and volatility, and we find that the volatility can be reduced by increasing the damping factor or preference, which provides the basis for eliminating the numerical oscillating. © Springer Science+Business Media Dordrecht 2014.
Zhu Q.M.,University of the West of England |
Zhang L.F.,Remin University of China |
Longden A.,University of the West of England
International Journal of Systems Science | Year: 2010
In the present study, a new correlation test-based nonlinear adaptive noise cancellation (ANC) validity monitoring procedure is proposed by following the insight and formulations which were developed by the authors for validating identified nonlinear dynamic models. The new method is based on the concept that if an ANC is valid, the recovered signal should be uncorrelated to the noise source. Then, a new correlation test between recovered signal and noise source is periodically computed to online check the validity of noise cancellers when ANCs are in operation. Simulation demonstrations on validity monitoring for recursive least squares-based ANC are conducted to illustrate the effectiveness and efficiency of the new procedure. © 2010 Taylor & Francis.
Liang X.,Remin University of China |
Liang X.,Stanford University
Neural Computing and Applications | Year: 2010
In machine-learning technologies, the support vector machine (SV machine, SVM) is a brilliant invention with many merits, such as freedom from local minima, the widest possible margins separating different clusters, and a solid theoretical foundation. In this paper, we first explore the linear separability relationships between the high-dimensional feature space H and the empirical kernel map U as well as between H and the space of kernel outputs K. Second, we investigate the relations of the distances between separating hyperplanes and SVs in H and U, and derive an upper bound for the margin width in K. Third, as an application, we show experimentally that the separating hyperplane in H can be slightly adjusted through U. The experiments reveal that existing SVM training can linearly separate the data in H with considerable success. The results in this paper allow us to visualize the geometry of H by studying U and K. © 2010 Springer-Verlag London Limited.
Gui B.,Remin University of China |
Yang X.,Remin University of China
Proceedings - 9th International Conference on Computational Intelligence and Security, CIS 2013 | Year: 2013
With the development of internet in China, Mic-croblogging provides a new platform for communicating and sharing information among Web users. Users can express opinions and record daily life using microblogs. Microblogs that are posted by users indicate their interests to some extent. But it seems very hard to analyze the sentiment hided in Chinese Micro text because of its complexity. This paper proposes a new way to determine the sentiment tendency of Chinese micro text based on the partitioned Sense Group(STDSG).When to judge the sentiment tendency of Micro text, we first partition it into separate sense group, and then determine it's sentiment tendency based on Emotional Dictionary. And We aslo consider various factors which contain negations, degree adverbs and punctuations. The effectiveness of STDSG is strongly supported by the results of our experiments. © 2013 IEEE.
Liang X.,Remin University of China |
Ni Z.,Remin University of China
IEEE Transactions on Neural Networks | Year: 2011
Standard support vector machines (SVMs) have kernels based on the Euclidean distance. This brief extends standard SVMs to SVMs with kernels based on the Mahalanobis distance. The extended SVMs become a special case of the Euclidean distance when the covariance matrix in a reproducing kernel Hilbert space is degenerated to an identity. The Mahalanobis distance leads to hyperellipsoidal kernels and the Euclidean distance results in hyperspherical ones. In this brief, the Mahalanobis distance-based kernel in a reproducing kernel Hilbert space is developed systematically. Extensive experiments demonstrate that the hyperellipsoidal kernels slightly outperform the hyperspherical ones, with fewer SVs. © 2011 IEEE.
Liang X.,Remin University of China
2010 International Conference on Computational Intelligence and Software Engineering, CiSE 2010 | Year: 2010
Support vector machine (SV machine, SVM) is a genius invention with many merits, such as the non-existence of local minima, the largest separating margins of different clusters, as well as the solid theoretical foundation. However, it is also well-noted that SVMs are frequently with a large number of SVs. In this paper, we investigate the number of SVs in a benchmark problem, the parity problem experimentally. With a large variety of kernel functions, the exhaustive experiments using LibSVM discover that for the N-bit parity problems all 2 N points are created as SVs. The study in this paper indicates that the SMO-based LibSVM training candidly incorporate every point in the parity problem. Since any two neighbored points in the N-bit parity problem are with the opposite signs, the SMO creates an SV each time in iterations for fast satisfying the Lagrangian conditions. As a corollary, the SMO-based SVM training is pretty much entangled into the local information and is therefore a greedy algorithm. ©2010 IEEE.