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A content aware chunking scheme for data de-duplication in archival storage systems

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High Technology Letters 2012年第1期18卷 45-50页

作者： Nie Xuejun Qin Leihua zhou jingli College of Computer Science&Technology Huazhong University of Science&TechnologyWuhan 430074P.R.China

Based on variable sized chunking, this paper proposes a content aware chunking scheme, called CAC, that does not assume fully random file contents, but tonsiders the characteristics of the file types. CAC uses a candidate anchor histogram and the file-type specific knowledge to refine how anchors are determined when performing de- duplication of file data and enforces the selected average chunk size. CAC yields more chunks being found which in turn produces smaller average chtmks and a better reduction in data. We present a detailed evaluation of CAC and the experimental results show that this scheme can improve the compression ratio chunking for file types whose bytes are not randomly distributed （from 11.3% to 16.7% according to different datasets）, and improve the write throughput on average by 9.7%.

关键词： data de-duplicate content aware chunking (CAC) candidate anchor histogram (CAH)

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高酸度醋补料发酵工艺优化

中国酿造 2024年第5期43卷 230-236页

作者：夏瑶瑶张峰闫裕峰郎繁繁梁楷周景丽食醋发酵科学与工程山西省重点实验室山西太原030400 山西紫林醋业股份有限公司山西太原030400

高酸度醋的酿造主要采用液态深层发酵技术,高酸度醋有利于储存和运输,但目前高酸度醋的发酵工艺仍不完善。该研究利用福林斯自吸式深层发酵装置,以酿造酸度为9 g/100 mL醋的醋酸菌作为发酵菌株,通过对发酵工艺的调控酿造高酸度醋。结果... 详细信息

高酸度醋的酿造主要采用液态深层发酵技术,高酸度醋有利于储存和运输,但目前高酸度醋的发酵工艺仍不完善。该研究利用福林斯自吸式深层发酵装置,以酿造酸度为9 g/100 mL醋的醋酸菌作为发酵菌株,通过对发酵工艺的调控酿造高酸度醋。结果表明,以14%vol酒精度发酵液进行高酸度醋的酿造,经单因素及响应面法试验得到最佳的发酵工艺条件为:采用直接补料法进行补料,补料时间2.5 h,通气量0.12 m^(3)/(m^(3)·min),营养盐添加量1.7‰,营养盐在补料时加1.3‰+罐内发酵液酒精度降至3.5%vol~2.5%vol时加0.4‰。在此优化条件下,高酸度醋的总酸含量为12.62 g/100 mL,发酵周期为34.06 h,产酸速率为0.12 g/(100 mL·L·h),乙醇转酸率为82.85%。

关键词：高酸度醋醋酸发酵补料发酵工艺优化

Data Location Mechanism in Agent-Based Autonomic Storage Systems

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Wuhan University Journal of Natural Sciences 2007年第2期12卷 249-254页

作者： SU Yong zhou jingli YU Shengsheng JIANG Minghua LIU Gang College of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 Hubei China College of Computer Science Wuhan University of Science and Engineering Wuhan 430073 Hubei China

This paper introduces agent-based methodology to build a distributed autonomic storage system infrastructure, and an effectively negotiation mechanism based on agent is applied for data location. We present Availability-based Data Allocation （ADA） algorithm as a data placement strategy to achieve high efficient utilization of storage resources by employing multiple distributed storage resources. We use Bloom filter in each storage device to track the location of data. We present the data lookup strategy that small size of read request is handled directly, and large size of read request is handled by cooperation with storage *** performance evaluation shows that the data location mechanism is high available and can work well for heterogeneous autonomic storage systems.

关键词： autonomic storage data location agent bloom filter

Optimization for data de-duplication algorithm based on file content

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Frontiers of Optoelectronics 2010年第3期3卷 308-316页

作者： Xuejun NIE Leihua QIN jingli zhou Ke LIU Jianfeng ZHU Yu WANG School of Computer Science and Technology Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology

Content defined chunking(CDC) is a prevalent data de-duplication algorithm for removing redundant data segments in archival storage systems. Current researches on CDC do not consider the unique content characteristic of different file types, and they determine chunk boundaries in a random way and apply a single strategy for all file types. It has been proven that such method cannot achieve optimal performance for compound archival data. We analyze the content characteristic of different file types and propose candidate anchor histogram(CAH) to capture it. We propose an improved strategy for determining chunk boundaries based on CAH and tune some key parameters of CDC based on the data layout of underlying data de-duplication file system(TriDFS), which can efficiently store variable-sized chunks on fixed-sized physical blocks. These strategies are evaluated with representative archival data, and the result indicates that they can increase on average the compression ratio by 16.3% and write throughput by 13.7%, while only decrease the read throughput by 2.5%.

关键词： data de-duplication content defined chunking (CDC) file content candidate anchor histogram (CAH)

A Fault Detection Mechanism in Erasure-Code Byzantine Fault-Tolerance Quorum

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Wuhan University Journal of Natural Sciences 2006年第6期11卷 1453-1456页

作者： LIU Gang zhou jingli SUN Yufen QIN Leihua College of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 Hubei China

Fault-tolerance is increasingly significant for large-scale storage systems in which Byzantine failure of storage nodes may happen. Traditional Byzantine Quorum systems that tolerate Byzantine failures by using replication have two main limitations： low space-efficiency and static quorum variables. We propose an Erasure-code Byzantine Fault-tolerance Quorum that can provide high reliability with far lower storage overhead than replication by adopting erasure code as redundancy scheme. Through read/write operations of clients and diagnose operation of supervisor, our Quorum system can detect Byzantine nodes, and dynamically adjust system size and fault threshold. Simulation results show that our method improves performance for the Quorum with relatively small quorums.

关键词： fault detection erasure code Byzantine fault-tolerance Quorum

A blockchain-based data auditing scheme with key-exposure resistance for IIoT

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Science China(Information Sciences) 2024年第2期67卷 327-328页

作者： Pan YANG jingli REN Henan Academy of Big Data Zhengzhou University

The Industrial Internet of Things(IIoT) enables enterprises to collect data from end devices and outsource the data to cloud servers for flexible data sharing. Public auditing plays an important role in ensuring the integrity of the *** are blockchain-based public auditing schemes that utilize smart contracts to achieve decentralized verification(such as [1]),

关键词：

AN EYE MOVEMENTS STUDY OF VISUAL SPACE ATTENTIONS EFFECT ON ONE-DIGIT NUMBER PROCESSING

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AN EYE MOVEMENTS STUDY OF VISUAL SPACE ATTENTIONS EFFECT ON ...

A Semi-Mechanistic Model for Predicting the Service Life of Composite Coatings on VW63Z Magnesium Alloy

第二届中国国际眼动大会

作者： Xiaohua Cao jingli zhou School of Education Zhejiang Normal University

The present study investigated participants’ eye movements characteristic(oculomotor characteristic),and examined number SNARC effect and number distance effect by a number comparison task in number *** focuses on the eye movements when comparing the single-number with 5,and discuss about the effects of three different attention experimental paradigms(without cue;with the endogenous cue;with the exogenous cue),cue utility(congruity cue and incongruity cue),and physical distance(far and nearby) in the number *** number magnitude(large:6 & small:1 ) was *** results showed that:(1) The effect of cue utility in the number processing’s fixation time and response time with the exogenous cue stronger than with the endogenous cue for SNARC effect;(2) The effect of cue utility in the number processing’s responce time with the exogenous cue more obvious than with the endogenous cue for distanct effect,but there weren’t distanct effect in three attention paradigms;(3) responsing target number lying in the nearby place better than lying in the far place,furthermore the effect of space position(far and nearby) with the exogenous cue lager than without cue and with the endogenous cue;(4) Attention size made impact on number processing,and number processing with the exogenous cue was significantly harder than without cue.

关键词： with the endogenous cue with the exogenous cue Space position SNARC effect Distanct effect.

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1161-1176页

作者： Xiaoxue Wang Jingjing Guo Zihao Zeng Peng zhou Rongqiao Wang Xiuchun Liu Kai Gao jingli Sun Yong Yuan Fuhui Wang School of Energy and Power Engineering Beihang UniversityBeijing100191China Beijing Institute of Space Long March Vehicle Beijing100076China The School of Materials Science and Engineering Northeastern UniversityShenyang110819China The State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China Shanghai Spaceflight Precision Machinery Institute Shanghai201600China

The application of Mg alloys is always accompanied by various coating technology, but a reliable model predicting the service life of coatings on Mg alloys is lacking but urgent. In this work, a semi-mechanistic model was proposed to predict the service life of plasma electrolytic oxidation (PEO) coating/electrophoretic coatings on a VW63Z Mg alloy;the model was decomposed into three parts: a first part depicting the degradation time of organic coating (L_(1)) and the diffusion time of electrolyte in the inorganic coating (L_(2)), respectively;a second part interpreting the breakdown of coatings due to the corrosion process (L_(3));a final part establishing an algorithm converting the accelerated tests into the real service environment (α);the effect of structural stress and dissimilar metal joints on the service life of coatings was also considered. Based on the ongoing accelerated experiments, the semi-mechanistic model could be able to predict the service life of both PEO coatings and composite coatings on VW63Z Mg alloy with a satisfiable precision.

关键词： Magnesium alloy Service life prediction Plasma electrolytic oxidation Electrophoretic coating Corrosion resistance

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iSCSI带外虚拟化的研究与实现

华中科技大学学报（自然科学版） 2005年第1期33卷 10-12页

作者：周敬利刘超杨光华中科技大学计算机科学与技术学院湖北武汉430074

研究了基于因特网小型计算机系统接口 (iSCSI)带外方式的存储虚拟化模型 ,提出了一种iSCSI带外存储虚拟化的体系结构及命令流程 .根据该体系结构 ,实现了基于iSCSI带外存储虚拟化的存储系统 ,并对该实现在低级别RAID下进行了读 /写性能... 详细信息

研究了基于因特网小型计算机系统接口 (iSCSI)带外方式的存储虚拟化模型 ,提出了一种iSCSI带外存储虚拟化的体系结构及命令流程 .根据该体系结构 ,实现了基于iSCSI带外存储虚拟化的存储系统 ,并对该实现在低级别RAID下进行了读 /写性能测试 .结果表明 ,读 /写性能随着传输数据块的变大而上升 ,当数据块的大小达到 6 4Kbyte时 ,RAID 0的读 /写和RAID 1的读 ,其性能已接近 30Mbyte/s .

关键词：存储虚拟化因特网小型计算机系统接口带外