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Asurvey on design and application of open-channel solid-state drives

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Frontiers of Information Technology & Electronic Engineering 2023年第5期24卷 637-658页

作者： Junchao CHEN guangyan zhang Junyu WEI Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China Xi’an Satellite Control Center Xi’an 710043China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China

Compared with traditional solid-state drives(SSDs),open-channel SSDs(OCSSDs)expose their internal physical layout and provide a host-based flash translation layer(FTL)that allows host-side software to control the internal operations such as garbage collection(GC)and input/output(I/O)scheduling.In this paper,we comprehensively survey research works built on OCSSDs in recent years.We show how they leverage the features of OCSSDs to achieve high throughput,low latency,long lifetime,strong performance isolation,and high resource utilization.We categorize these efforts into five groups based on their optimization methods:adaptive interface customizing,rich FTL co-designing,internal parallelism exploiting,rational I/O scheduling,and efficient GC processing.We discuss the strengths and weaknesses of these efforts and find that almost all these efforts face a dilemma between performance effectiveness and management complexity.We hope that this survey can provide fundamental knowledge to researchers who want to enter this field and further inspire new ideas for the development of OCSSDs.

关键词： Domain-specific storage Flash translation layer Garbage collection Internal parallelism Open-channel solid-state drives(OCSSDs)

Short Tail:taming tail latency for erasure-code-based in-memory systems

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Frontiers of Information Technology & Electronic Engineering 2022年第11期23卷 1646-1657页

作者： Yun TENG Zhiyue LI Jing HUANG guangyan zhang College of Computer Science and Technology Jilin UniversityChangchun 130012China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education Jilin UniversityChangchun 130012China Beijing National Research Center for Information Science and Technology(Tsinghua University) Beijing 100084China

In-memory systems with erasure coding(EC)enabled are widely used to achieve high performance and data availability.However,as the scale of clusters grows,the server-level fail-slow problem is becoming increasingly frequent,which can create long tail latency.The influence of long tail latency is further amplified in EC-based systems due to the synchronous nature of multiple EC sub-operations.In this paper,we propose an EC-enabled in-memory storage system called ShortTail,which can achieve consistent performance and low latency for both reads and writes.First,ShortTail uses a lightweight request monitor to track the performance of each memory node and identify any fail-slow node.Second,ShortTail selectively performs degraded reads and redirected writes to avoid accessing fail-slow nodes.Finally,ShortTail posts an adaptive write strategy to reduce write amplification of small writes.We implement ShortTail on top of Memcached and compare it with two baseline systems.The experimental results show that ShortTail can reduce the P99 tail latency by up to 63.77%;it also brings significant improvements in the median latency and average latency.

关键词： Erasure code In-memory system Node fail-slow Small write Tail latency

Design and application of new storage systems

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Frontiers of Information Technology & Electronic Engineering 2023年第5期24卷 633-636页

作者： guangyan zhang Dan FENG Keqin LI Zili SHAO Nong XIAO Jin XIONG Weimin ZHENG Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China School of Computer Science and Technology Huazhong University of Science and TechnologyWuhan 430074China Department of Computer Science State University of New YorkNY 12561USA Department of Computer Science and Engineering The Chinese University of Hong KongHong KongChina School of Computer Science and Engineering Sun Yat-sen UniversityGuangzhou 510000China Institute of Computing Technology Chinese Academy of SciencesBeijing 100190China

A storage system is the core of a computer,and plays an important role in the sustainable development of emerging strategic industries,such as artificial intelligence,big data,cloud computing,and the Internet of Things.Storage stack access is a major factor restricting the performance of data-intensive systems because of the increasing performance of processors and network devices.

关键词： computer artificial application

Removing lignin model pollutants with BiFeO_3–g-C_3N_4 compound as an efficient visible-light-heterogeneous Fenton-like catalyst

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Journal of Environmental Sciences 2016年第10期28卷 218-229页

作者： Junjian An guangyan zhang Rongfeng Zheng Peng Wang School of Pulp and Paper Engineering Hubei Provincial Key Laboratory of Green Materials for Light Industry Hubei University of Technology

BiFeO3-g-C3N4 nanoscaled composite was prepared with a hydrothermal method and evaluated as a highly efficient photo-Fenton like catalyst under visible light irradiation. The BiFeO3-g-CHN4 composite exhibited much stronger adsorption ability to lignin model pollutant （guaiacol） than that of BiFeO3, which may be due to the higher specific surface area （BiFeO3-g-C3N4：35.59 m2/g 〉 BiFeO3：7.42 m2/g） and the adsorption form of π-π stack between g-C3N4 and guaiacol. The composite exhibited excellent visible light-Fenton like catalysis activity, being influenced by the solution pH value and the proportions of BiFe03 and g-C3N4 nanosheets. Under optimal conditions with visible light irradiation, the BiFeO3- g-C3N4 composite yielded fast degradation of guaiacol with an apparent rate constant of 0.0452 rain-I, which were 5.21 and 6.80 folds of that achieved by using BiFeO3 and the mixture of BiFeO3 and g-C3N4 nanosheets, respectively. The significantly enhanced visible light-Fenton like catalytic properties of the BiFeO3-g-C3N4 composite in comparison with that of BiFeO3 was attributed to a large surface area, much increased adsorption capacity and the semiconductor coupling effect between BiFe03 and g-C3N4 in the composite.

关键词： BiFeO3g-C3N4 nanosheetsHeterogeneous Fenton-like catalysisVisible light catalystDegradation

An efficient and facile approach for the construction of chondroitin sulfate E oligosaccharide precursors

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Chinese Chemical Letters 2019年第3期30卷 686-689页

作者： guangyan zhang Qi Liu Shuang Yang Zhehui Zhao Pingsheng Lei State Key Laboratory of Bioactive Substance and Function of Natural Medicines Beijing Key Laboratory of Active Substances Discovery and Drug ability Evaluation Department of Medicinal Chemistry Institute of Materia Medica & Peking Union Medical College Chinese Academy of Medical Sciences

An efficient and facile approach has been developed for the construction of chondroitin sulfate E(CS-E)oligosaccharide precursors. In this approach, the disaccharide unit with the GalNAc-GIcA sequence was first elongated to form tetra-and hexasaccharides followed by the introduction of anomeric groups via glycosylation couplings. A number of CS-E tetra-and hexasaccharide precursors were prepared in high yields.

关键词： Chon droitin sulfate E Glycosylation Oligosaccharide Anomeric group Modification

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云计算环境下数据通信的智能路由算法研究

通信电源技术 2024年第5期41卷 176-178页

作者：张光艳北京市委党校(北京行政学院) 北京100044

文章以深度强化学习模型为核心,研究了云计算环境下的数据通信智能路由算法。通过状态空间建模、动作空间定义、奖励机制及深度强化学习算法的综合应用,实现了对系统性能多方面的综合优化。在对比实验中,将该智能路由算法与传统路由协... 详细信息

文章以深度强化学习模型为核心,研究了云计算环境下的数据通信智能路由算法。通过状态空间建模、动作空间定义、奖励机制及深度强化学习算法的综合应用,实现了对系统性能多方面的综合优化。在对比实验中,将该智能路由算法与传统路由协议进行了全面对比,验证了其在收敛时间、数据传输效率、路由表更新频率以及负载均衡性能等关键指标上的优越性。这些研究结果不仅为云计算环境下智能路由的应用提供了创新性的思路,也为构建更智能、高效的云计算系统奠定了基础。

关键词：智能路由算法云计算数据通信强化学习

肝硬化96例血清中微RNA-454和Wnt10a的表达及其临床意义

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安徽医药 2024年第1期28卷 172-176页

作者：卢忠友顿晓琴胡莉张光燕吴小微武汉科技大学附属汉阳医院消化内科湖北武汉430000

目的探究肝硬化病人血清中微RNA(microRNA,miR)-454和无翅型小鼠乳腺肿瘤病毒整合位点家族成员10a(Wnt10a)的表达及其临床意义。方法以2018年2月至2020年12月入住武汉科技大学附属汉阳医院的96例肝硬化病人为肝硬化组,并根据Child-Pugh... 详细信息

目的探究肝硬化病人血清中微RNA(microRNA,miR)-454和无翅型小鼠乳腺肿瘤病毒整合位点家族成员10a(Wnt10a)的表达及其临床意义。方法以2018年2月至2020年12月入住武汉科技大学附属汉阳医院的96例肝硬化病人为肝硬化组,并根据Child-Pugh分级分为A级36例、B级31例、C级29例。另选60例健康体检者为对照组。抽取空腹外周血检测天冬氨酸转氨酶(AST)、白蛋白(ALB)、丙氨酸转氨酶(ALT)等肝功能指标,qRT-PCR法检测血清中miR-454和Wnt10a表达水平,并分析miR-454、Wnt10a与Child-Pugh分级评分及AST、ALT、ALB等肝功能指标的关系;受试者操作特征(ROC)曲线分析miR-454、Wnt10a对严重肝硬化的诊断效能。结果肝硬化组miR-454表达水平0.85±0.20)显著低于对照组1.46±0.29,Wnt10a表达水平1.67±0.31显著高于对照组0.94±0.23(P0,P0,P<0.05);miR-454、Wnt10a诊断严重性肝硬化的曲线下面积分别为0.80[95%CI:(0.71,0.88)]、0.73[95%CI:(0.621,0.837)];miR-454与Wnt10a联合诊断的曲线下面积为0.84[95%CI:(0.75,0.93)]。结论肝硬化病人血清中miR-454下调表达,Wnt10a上调表达,miR-454和Wnt10a呈负相关性,二者均与肝功能损伤有关,有作为诊断肝硬化严重程度的潜能。

关键词：肝硬化微RNA-454 无翅型小鼠乳腺肿瘤病毒整合位点家族成员10a 谷草转氨酶白蛋白类谷丙转氨酶

Effect of wall-disruption on nutrient composition and in vitro digestion of camellia and lotus bee pollens

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Food Science and Human Wellness 2024年第3期13卷 1567-1577页

作者： Yuan Yuan Shun Zhong Zeyuan Deng guangyan Li Jinwu zhang Hongyan Li State Key Laboratory of Food Science and Resources Nanchang UniversityNanchang 330047China Nanchang Tongxin Zichao Biological Engineering Co. Ltd.Nanchang 330052China

The nutrient digestion,absorption and biological activity of bee pollen may be limited due to the complex pollen wall.Here,the effect of superfine grinding technology on the release of nutrients from bee pollen were investigated,and their antioxidant activities and in vitro digestion were explored in this study.Results showed that the content of nutrients in bee pollen increased after wall disruption.Among them,fat content increased by 22.55%-8.31%,protein content increased by 0.54%-4.91%,starch content increased by 36.31%-48.64%,soluble sugar content increased by 20.57%-29.67%,total phenolic acid content increased by 11.73%-86.98%and total flavonoids content increased by 14.29%-24.79%.At the same time,the antioxidant activity increased by 14.84%-46.00%.Furthermore,the active components such as phenolic compounds in the wall-disruption bee pollen were more readily to be released during the in vitro digestion,and easier to be absorbed because of their higher bioaccessibility.Antioxidant activities during in vitro digestion were also improved in walldisruption bee pollen.These findings provide evidence that bee pollen wall disruption was suggested,thus,it is more conducive to exerting the value of bee pollen in functional foods.

关键词： Bee pollen Nutrients Wall disruption Phenolic compounds In vitro digestion

AIP:a tool for flexible and transparent data management

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Science China(Information Sciences) 2013年第5期56卷 191-201页

作者： zhang guangyan QIU JianPing SHU JiWu ZHENG WeiMin Department of Computer Science and Technology Tsinghua University Tsinghua National Laboratory for Information Science and Technology Tsinghua University

Existing data management tools have some limitations such as restrictions to specific file systems or shortage of transparence to applications.In this paper,we present a new data management tool called AIP,which is implemented via the standard data management API,and hence it supports multiple file systems and makes data management operations transparent to applications.First,AIP provides centralized policy-based data management for controlling the placement of files in different storage tiers.Second,AIP uses differentiated collections of file states to improve the execution efficiency of data management policies,with the help of the caching mechanism of file states.Third,AIP also provides a resource arbitration mechanism for controlling the rate of initiated data management operations.Our results from representative experiments demonstrate that AIP has the ability to provide high performance,to introduce low management overhead,and to have good scalability.

关键词： data management DMAPI management policy differentiated collection resource arbitration