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Efficient Processing of Distributed Twig Queries Based on Node Distribution

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Journal of Computer Science & Technology 2017年第1期32卷 78-92页

作者： xin Bi Xiang-Guo Zhao Guo-ren Wang College of Computer Science and Engineering Northeastern University Shenyang 110815 China

Massive XML data are increasingly generated for the representation, storage and exchange of web information. Twig query processing over massive XML data has become a research focus. However, most traditional algorithms cannot be directly implemented in a distributed manner. Some of the existing distributed algorithms generate a lot of useless intermediate results and execute many join operations of partial results in most cases; others require the priori knowledge of query pattern before XML partition, storage and query processing, which is impractical in the cases of large-scale data or frequent incoming new queries. To improve efficiency and scalability, in this paper, we propose a 3-phase distributed algorithm DisT3 based on node distribution mechanism to avoid unnecessary intermediate results. Furthermore, we propose a lightweight local index ReP with an enhanced XML partitioning approach using arbitrary partitioning strategy, and based on ReP we propose an improved 2-phase distributed algorithm DisT2ReP to further reduce the communication cost. After the performance guarantees are analyzed, extensive experiments are conducted to verify the efficiency and scalability of our proposed algorithms in distributed twig query applications.

关键词： XML twig query distributed computing node distribution

The optimal information rate for graph access structures of nine participants

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Frontiers of Computer Science 2015年第5期9卷 778-787页

作者： Yun SONG Zhihui LI Yongming LI ren xin College of Mathematics and Information Science Shaanxi Normal University Xi'an 710062 China College of Computer Science Shaanxi Normal University Xi'an 710062 China School of Civil Engineering Xi'an University of Architecture and Technology Xi'an 710055 China

The information rate is an important metric of the performance of a secret-sharing scheme. In this paper we consider 272 non-isomorphic connected graph access structures with nine vertices and eight or nine edges, and either determine or bound the optimal information rate in each case. We obtain exact values for the optimal information rate for 231 cases and present a method that is able to derive information-theoretical upper bounds on the optimal information rate. Moreover, we apply some of the constructions to determine lower bounds on the information rate. Regarding information rate, we conclude with a full listing of the known optimal information rate （or bounds on the optimal information rate） for all 272 graphs access structures of nine participants.

关键词： optimal information rate perfect secret-sharingscheme entropy method graph access structure splittingconstruction L-decomposition weighted decomposition

Irradiance regression for efficient final gathering in global illumination

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Frontiers of Computer Science 2015年第3期9卷 456-465页

作者： Xuezhen HUANG xin SUN Zhong ren xin TONG Baining GUO Kun ZHOU State Key Laboratory of Computer Aided Design and Computer Graphics Zhejiang University Hangzhou 310058 China Microsoft Research Asia Beijing 100029 China

Photon mapping is widely used for global illumi- nation rendering because of its high computational efficiency. But its efficiency is still limited, mainly by the intensive sam- piing required in final gathering, a process that is critical for removing low frequency artifacts of density estimation. In this paper, we propose a method to predict the final gather- ing estimation with direct density estimation, thereby achiev- ing high quality global illumination by photon mapping with high efficiency. We first sample the irradiance of a subset of shading points by both final gathering and direct radiance es- timation. Then we use the samples as a training set to predict the final gathered irradiance of other shading points through regression. Consequently, we are able to achieve about three times overall speedup compared with straightforward final gathering in global illumination computation with the same rendering quality.

关键词： global illumination photon mapping final gath-ering radiance estimation regression

Graph Attention Residual Network Based Routing and Fault-Tolerant Scheduling Mechanism for Data Flow in Power Communication Network

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Computers, Materials & Continua 2024年第10期81卷 1641-1665页

作者： Zhihong Lin zeng zeng Yituan Yu Yinlin ren Xuesong Qiu Jinqian Chen State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing100876China State Grid Jiangsu Electric Power Co. Ltd.Nanjing210008China

For permanent faults(PF)in the power communication network(PCN),such as link interruptions,the timesensitive networking(TSN)relied on by PCN,typically employs spatial redundancy fault-tolerance methods to keep service stability and reliability,which often limits TSN scheduling performance in fault-free ideal *** this paper proposes a graph attention residual network-based routing and fault-tolerant scheduling mechanism(GRFS)for data flow in PCN,which specifically includes a communication system architecture for integrated terminals based on a cyclic queuing and forwarding(CQF)model and fault recovery method,which reduces the impact of faults by simplified scheduling configurations of CQF and fault-tolerance of prioritizing the rerouting of faulty time-sensitive(TS)flows;considering that PF leading to changes in network topology is more appropriately solved by doing routing and time slot injection decisions hop-by-hop,and that reasonable network load can reduce the damage caused by PF and reserve resources for the rerouting of faulty TS flows,an optimization model for joint routing and scheduling is constructed with scheduling success rate as the objective,and with traffic latency and network load as constraints;to catch changes in TSN topology and traffic load,a D3QN algorithm based on a multi-head graph attention residual network(MGAR)is designed to solve the problem model,where the MGAR based encoder reconstructs the TSN status into feature embedding vectors,and a dueling network decoder performs decoding tasks on the reconstructed feature embedding *** results show that GRFS outperforms heuristic fault-tolerance algorithms and other benchmark schemes by approximately 10%in routing and scheduling success rate in ideal states and 5%in rerouting and rescheduling success rate in fault states.

关键词： Time-sensitive network deep reinforcement learning graph attention network fault tolerance

Investigation on Effects of Mooring Line Fractures and Connector Failures for A Hybrid Modular Floating Structure System

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China Ocean Engineering 2022年第6期36卷 880-893页

作者： LIU Ya-qiong ren Nian-xin OU Jin-ping School of Civil and Environmental Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China College of Civil Engineering and Architecture Hainan UniversityHaikou 570228China

The present work reports a Hybrid Modular Floating Structure(HMFS)system with typical malfunction *** effects of both fractured mooring lines and failed connectors on main hydrodynamic responses(mooring line tensions,module motions,connector loads and wave power production)of the HMFS system under typical sea con-ditions are comparatively *** results indicate that the mooring tension distribution,certain module motions(surge,sway and yaw)and connector loads(Mz)are significantly influenced by mooring line *** adjacent mooring line of the fractured line on the upstream side suffers the largest tension among the remaining mooring lines,and the case with two fractured mooring lines in the same group on the upstream side is the most dangerous among all cases of two-line failures in view of mooring line tensions,module motions and connector ***-fore,one emergency strategy with appropriate relaxation of a proper mooring line has been proposed and proved effective to reduce the risk of more progressive mooring line *** addition,connector failures substantially affect certain module motions(heave and pitch),certain connector loads(Fz and My)and wave power *** present work can be helpful and instructive for studies on malfunction conditions of modular floating structure(MFS)systems.

关键词： Hybrid Modular Floating Structure(HMFS)system mooring line fractures connector failures hydrodynamic responses emergency strategy

P-μc-Si_(1-x)Ge_x:H thin film by VHF-PECVD

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Optoelectronics Letters 2008年第2期4卷 130-132页

作者： SHANG Ze-ren ZHANG Jian-jun ZHANG Li-ping HU zeng-xin XUE Jun-ming ZHAO Ying GENG xin-hua Key Laboratory of Photo-Electronics Thin Film Devices and Technique of Tianjin Key Laboratory of OPtoelectronic Information Science and Technology of Education Ministry Institute of Photo-Electronics Thin Film Devices and Technology Nankai University Tianjin 300071 China

In this paper, a series of boron doped microcrystalline hydrogenated silicon-germanium （p-μc-Si1-xGex：H） was deposited by very high frequency plasma-enhanced chemical vapor deposition （VHF-PECVD） from SiH4 and GeF4 mixtures. The effect of GeF4 concentration on films＇ composition, structure and electrical properties was studied. The results show that with the increase of GeF4 concentration, the Ge fraction x increases. The dark conductivity and crystalline volume fraction increase first, and then decrease. When the GC is 4%, p-μc-Si1-xGex：H material with high conductivity, low activation energy （σ= 1.68 S/cm, E8=0.047 eV）, high crystalline volume fraction （60%） and with an average transmission coefficient over the long wave region reaching 0.9 at the thickness of 72 nm was achieved. The experimental results were discussed in detail.

关键词： VHF-PECVD 薄膜化学纤维光半导体

Environmental evolution recorded by multi-proxy evidence in Lake Chenghai sediments, Yunnan Province during recent 100 years

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Chinese Journal Of Geochemistry 2013年第1期32卷 47-55页

作者： ZHU Zhengjie CHEN Jing'an ren Shicong zeng Yan The State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Chongqing Key Laboratory of Exogenic Mineralization and Mine Environment Chongqing Institute of Geology and Mineral Resources Chongqing Research Center of State Key Laboratory of Coal Resources and Safe Mining

Lacustrine sediments can provide potential information about environmental changes in the past. On the basis of high-resolution multi-proxy analysis including carbon and nitrogen contents of organic matter, C/N ratios, inorganic carbon contents, and carbon and oxygen isotopic composition of carbonate, together with precise 137Cs dating, the environmental evolution of Lake Chenghai, Yunnan Province, during the past 100 years has been investigated. It is shown that the carbonate in Lake Chenghai is authigenic, and the organic matter is mainly derived from aquatic plants and algae, instead of terrestrial-source materials. The environmental evolution of Lake Chenghai can be diverged into three periods with the contrasting characteristics during the past 100 years. Before 1940, the stable carbon and oxygen isotope values, the poor correlation between them and the lower carbon and nitrogen contents of organic matter suggested that Lake Chenghai was open, and the lake water was oligotrophic during that period. During 1940-1993, the negative δ13C values and the gradual increase of carbon and nitrogen contents of organic matter and C/N ratios indicated that the eutrophication was aggravated. The closeness of Lake Chenghai and human activities may be responsible for this eutrophication. After 1993, notable increases in carbon and oxygen isotopic values of carbonate, carbon and nitrogen contents of organic matter, C/N ratios and inorganic carbon contents demonstrated that the increase of lacustrine productivity and the serious eutrophication were resulted from strong human activities. Therefore, the multi-proxy in Lake Chenghai sediments has reliably recorded the natural environmental evolution and the impacts from human activities.

关键词：湖泊沉积物环境演变多代理云南省程海氧同位素组成水体富营养化人类活动影响

Identification of late-onset hypogonadism in middle-aged and elderly men from a community of China

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Asian Journal of Andrology 2016年第5期18卷 747-753页

作者： Zhi-Yong Liu ren-Yuan Zhou xin Lu Qin-Song zeng Hui-Qing Wang Zheng Li Ying-Hao Sun Department of Urology Changhai Hospital Second Military Medical University Shanghai China Department of Urology Fifth People's Hospital of ShanghaiFudan University Shanghai China Department of Urology Renji Hospital Jiao Tong University Shanghai China

In this study, we investigated the essential criteria for late-onset hypogonadism （LOH） syndrome based on the presence of symptoms associated with low testosterone levels in Han Chinese men. Blood tests for total testosterone （TT） and sex hormone-binding globulin （SHBG） were performed, and the aging male symptoms （AMS） questionnaire was conducted in a randomly selected cohort composed of 944 Chinese men aged 40 to 79 years from nine urban communities. Three sexual symptoms （decreased ability/frequency of sexual activity, decreased number of morning erections, and decreased libido） were confirmed to be related to the total and free testosterone levels. The thresholds for TT were approximately 12.55 nmol l^-1 for a decreased ability/frequency to perform sex, 12.55 nmol l^-1 for decreased frequency of morning erections, and 14.35 nmol l^-1 for decreased sexual desire. The calculated free testosterone （CFT） thresholds for these three sexual symptoms were 281.14, 264.90, and 287.21 pmol l^-1, respectively. TT 〈13.21 nmol l^-1 （OR =1.4, 95%Ch 1.0-1.9, P= 0.037） or CFT 〈268.89 pmol l^-1 （OR - 1.5, 95%Ch 1.1-20, P=0.020） was associated with an increase in the aforementioned three sexual symptoms. The prevalence of LOH was 9.1% under the criteria, including all three sexual symptoms with TT levels 〈13.21 nmol l^-1 and CFT levels 〈268.89 pmol l^-1. Our results may improve the diagnostic accuracy of LOH in older men.

关键词： diagnosis hypogonadism middle-aged and elderly male reference values sexual dysfunction testosterone

Numerical modelling of MOV with Voronoi network and finite element method

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High Voltage 2021年第4期6卷 711-717页

作者： Qibin Zhou Hongxiang Yang xin Huang Manyu Wang xin ren School of Mechatronic Engineering and Automation Shanghai UniversityShanghaiChina Shanghai Railway Communication Co. Ltd.ShanghaiChina Research Center of Nanoscience and Technology Shanghai UniversityShanghaiChina

The electrical and thermal characteristics of metal oxide varistor(MOV)are essential for the study of MOV performance and *** paper provides a modelling method of MOV to simulate its microstructure geometry with the Voronoi network and derive the electrical functions on the grain boundaries.A series of discrete data to describe the resistance-voltage(R-V)characteristics of MOV from experiments is applied to the pro-posed *** 8/20μs surge current experiments,the electrical conductivity of MOV is determined to achieve the simulation of the clamping *** this model,the current distribution and temperature distribution over a MOV sample are simulated and analysed by the finite element method(FEM).The simulation results show good agreement with the experimental measurement and inherent feature of MOV.

关键词： network element finite