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WATuning:A Workload-Aware Tuning System with Attention-Based Deep Reinforcement Learning

Journal of Computer Science & Technology 2021年第4期36卷 741-761页

作者： Jia-Ke Ge Yan-feng chai Yun-Peng chai Key Laboratory of Data Engineering and Knowledge Engineering of Ministry of Education Renmin University of China Beijing 100872China School of Information Renmin University of ChinaBeijing 100872China College of Computer Science and Technology Taiyuan University of Science and TechnologyTaiyuan 030027China

Configuration tuning is essential to optimize the performance of systems(e.g.,databases,key-value stores).High performance usually indicates high throughput and low *** present,most of the tuning tasks of systems are performed artificially(e.g.,by database administrators),but it is hard for them to achieve high performance through tuning in various types of systems and in various *** recent years,there have been some studies on tuning traditional database systems,but all these methods have some *** this article,we put forward a tuning system based on attention-based deep reinforcement learning named WATuning,which can adapt to the changes of workload characteristics and optimize the system performance efficiently and ***,we design the core algorithm named ATT-Tune for WATuning to achieve the tuning task of *** algorithm uses workload characteristics to generate a weight matrix and acts on the internal metrics of systems,and then ATT-Tune uses the internal metrics with weight values assigned to select the appropriate ***,WATuning can generate multiple instance models according to the change of the workload so that it can complete targeted recommendation services for different types of ***,WATuning can also dynamically fine-tune itself according to the constantly changing workload in practical applications so that it can better fit to the actual environment to make *** experimental results show that the throughput and the latency of WATuning are improved by 52.6%and decreased by 31%,respectively,compared with the throughput and the latency of CDBTune which is an existing optimal tuning method.

关键词： attention mechanism auto-tuning system reinforcement learning(RL) workload-aware

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Stepwise approach for view synthesis

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第8期8卷 1218-1226页

作者： chai Deng-feng PENG Qun-sheng State Key Lab of CAD and CG Zhejiang University Hangzhou 310027 China Institute of Spatial Information Technique Zhejiang University Hangzhou 310027 China

This paper presents some techniques for synthesizing novel view for a virtual viewpoint from two given views cap-tured at different viewpoints to achieve both high quality and high efficiency. The whole process consists of three passes. The first pass recovers depth map. We formulate it as pixel labelling and propose a bisection approach to solve it. It is accomplished in log2n(n is the number of depth levels) steps,each of which involves a single graph cut computation. The second pass detects occluded pixels and reasons about their depth. It fits a foreground depth curve and a background depth curve using depth of nearby fore-ground and background pixels,and then distinguishes foreground and background pixels by minimizing a global energy,which involves only one graph cut computation. The third pass finds for each pixel in the novel view the corresponding pixels in the input views and computes its color. The whole process involves only a small number of graph cut computations,therefore it is efficient. And,visual artifacts in the synthesized view can be removed successfully by correcting depth of the occluded pixels. Experimental results demonstrate that both high quality and high efficiency are achieved by the proposed techniques.

关键词： View synthesis Occlusion Graph cut

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Effect of Cr on Characteristic of Rust Layer Formed on Low Alloy Steel in Flow-accelerated Corrosion Environment

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Journal of Iron and Steel Research International 2016年第6期23卷 602-607页

作者： feng chai Shan JIANG Cai-fu YANG Department of Engineering Steels Central Iron and Steel Research Insititute

The flow-accelerated corrosion experiments were carried out to research the effect of Cr on the rust layers formed on the carbon steel and Cr-containing steel,as well as the structure of rust layer of the two experimental *** influence of Cr on the flow-accelerated corrosion resistance and the corrosion morphology of inner rust layer formed on the Cr-containing steel were studied by the methods of polarization curves,scanning electron microscope,transmission electron microscope,and X-ray photoelectron *** distribution of Cr and its form of existence in the inner rust layer were *** results show that corroded mass loss of Cr-containing steel is lower than that of carbon steel and its inner rust layer is *** exists in the form of Fe2CrO4 and is enriched in the inner rust *** concentration could make the inner rust layer exhibit the tendency of *** phenomenon is related to fine *** inner rust layer becomes more compact because of the formation of fine Fe2CrO4,and the protectiveness of inner rust layer could be improved remarkably.

关键词： accelerated photoelectron amorphous remarkably steels finer enriched cathodic hence attributed

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Hot roll bonding between commercially pure titanium and high-strength low-alloy steel using Fe interlayer

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Journal of Iron and Steel Research International 2019年第10期26卷 1126-1136页

作者： Xi-yang chai Gang Chen feng chai Tao Pan Zhi-gang Yang Cai-fu Yang Department of Structural Steel Central Iron and Steel Research InstituteBeijing 100081China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Hot roll bonding was carried out between commercially pure titanium TA2 and high-strength low-alloy steel Q390 using no interlayer and Fe interlayer at temperatures of 850,900,950 and 1000℃with a total reduction ratio of 86.7%.Interfacial microstructure and bonding property of clad plates were investigated by electron microscopy and shear *** results showed that with the increase in heating temperature,the shear strength of titanium clad steel plates decreases *** with that of titanium clad steel plates with no interlayer,inserting Fe interlayer between titanium and steel can improve the shear strength at 850 and 900℃but deteriorate the shear strength at 950 and 1000℃.The reason for this consequence was that Fe interlayer prevented the reaction diffusion of C in titanium to form a thinner TiC layer at 850 and 900℃,while Fe interlayer promoted the reaction diffusion of Fe in titanium to generate thicker Fe2Ti and FeTi intermetallic compound layers at 950 and 1000℃.

关键词： Titanium clad steel plate Fe interlayer TiC Intermetallic compound Hot roll bonding

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MiR-32-5p aggravates intestinal epithelial cell injury in pediatric enteritis induced by Helicobacter pylori

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World Journal of Gastroenterology 2019年第41期25卷 6222-6237页

作者： Jing feng Jian Guo Jun-Ping Wang Bao-feng chai Institute of Loess Plateau Shanxi UniversityTaiyuan 030006Shanxi ProvinceChina Department of Gastroenterology Shanxi Provincial People's HospitalThe Affiliated People's Hospital of Shanxi Medical UniversityTaiyuan 030012Shanxi ProvinceChina Department of General Surgery Shanxi Provincial People's HospitalThe Affiliated People's Hospital of Shanxi Medical UniversityTaiyuan 030012Shanxi ProvinceChina

BACKGROUND Pediatric enteritis is one of the infectious diseases in the digestive system that causes a variety of digestive problems,including diarrhea,vomiting,and bellyache in ***,Helicobacter pylori(***)infection is one of the common factors to cause pediatric *** has been demonstrated that aberrant expression of microRNAs(miRNAs)is found in gastrointestinal diseases caused by ***,and we discovered a significant increase of miR-32-5p in ***-related pediatric ***,the exact role of miR-32-5p in it is still *** To investigate the role of aberrant miR-32-5p in pediatric enteritis induced by *** MiR-32-5p expression was detected by quantitative real time-polymerase chain *** biological role of miR-32-5p in ***-treated intestinal epithelial cells was evaluated by Cell Counting Kit-8 assay and flow *** potential target of miR-32-5p was predicted with TargetScanHuman and verified by luciferase *** downstream mechanism of miR-32-5p was explored by using molecular biology *** We found that miR-32-5p was overexpressed in serum of ***-induced pediatric *** investigation revealed that *** infection promoted the death of intestinal epithelial cells,and increased miR-32-5p ***,miR-32-5p mimic further facilitated apoptosis and inflammatory cytokine secretion of intestinal epithelial *** exploration revealed that SMAD family member 6(SMAD6)was the direct target of miR-32-5p,and SMAD6 overexpression partially rescued cell damage induced by *** following experiments showed that miR-32-5p/SMAD6 participated in the apoptosis of intestinal epithelial cells induced by transforming growth factor-β-activated kinase 1(TAK1)-p38 activation under *** *** Our work uncovered the crucial role of aberrant expression of miR-32-5p in ***–related pediatric enteritis,and suggested that the TAK1-p38

关键词： MiR-32-5p SMAD family member 6 Transforming growth factor-β-activated kinase 1 Apoptosis Enteritis Helicobacter pylori

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Interlayer engineering for titanium clad steel by hot roll bonding

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Journal of Iron and Steel Research International 2018年第7期25卷 739-745页

作者： Xi-yang chai Tao Pan feng chai Xiao-bing Luo Hang Su Zhi-gang Yang Cai-fu Yang Department of Structural Steels Central Iron and Steel Research Institute Beijing 100081 China School of Materials Science and Engineering Tsinghua University Beijing 100084 China

Hot roll bonding was carried out between commercially pure titanium TA2 and high-strength low-alloy steel Q390 using pure Nb or Mo interlayer at 950 ~C with a total reduction ratio of 86.7%. Interfacial microstructure and bonding properties of titanium clad steel plates were investigated by electron microscopy and mechanical tests. The results showed β-Ti, TiC and Fe2Ti reaction phases were generated at Ti/steel interface for the clad plates with no interlayer. Inserting Nb or Mo interlayer can effectively suppress the formation of brittle phases, while the weak bonding joint transferred to Nb/steel or Mo/steel interface. And some micro-voids were found at the interface of Nb/steel and Mo/steel. The improved shear strength of clad plates with Nb interlayer might be attributed to the elimination of brittle phases at bonding interface. The small size and little quantities of the micro-voids at Nb/steel interface had a relatively weak effect on shear strength. However, the large number and big size of micro-voids were responsible for the degradation of shear strength for the clad plates with Mo interlayer.

关键词： Titanium clad steel Interlayer - Interfacial microstructure Brittle phase Micro-void

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LC-MS/MS analysis and pharmacokinetic study on five bioactive constituents of Tanreqing injection in rats

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Chinese Journal of Natural Medicines 2016年第10期14卷 769-775页

作者： ZHANG feng SUN Liang GAO Shou-Hong CHEN Wan-Sheng chai Yi-feng Department of Pharmacy Changzheng HospitalSecond Military Medical University Department of Pharmaceutical Analysis School of Pharmacy Second Military Medical University Department of Pharmacy The 98th Hospital of PLA

Tanreqing injection(TRQ), a well-known traditional Chinese medicine formula, is commonly used to treat respiratory diseases. In the present study, a rapid, selective, and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS) method was developed and validated to simultaneously determinate the plasma contents of 5 major constituents of TRQ, including chlorogenic acid(CHA), caffeic acid(CFA), baicalin(BA), ursodeoxycholic acid(UDCA) and chenodeoxycholic acid(CDCA) in rats after intravenous administration of TRQ. Chromatographic separation was performed on an Agilent Zorbax SB-C_(18) column(3.5 μm, 100 mm × 2.1 mm), with acetonitrile and 0.1% aqueous formic acid as mobile phase at a flow rate of 0.3 m L·min^(^(-1)). The calibration curves were linear over the ranges of 27.0–13 333.0 ng·m L^(-1) for CFA, 30.0–14 933.0 ng·m L^(-1) for CHA, 50.0–50 333.0 ng·m L^(-1) for BA, 550.0–55 000.0 ng·m L^(-1) for UDCA, and 480.0–48 000.0 ng·m L^(-1) for CDCA, respectively. Intra- and inter-day precisions(relative standard deviations, RSDs) were from 3.11% to 14.08%. The extraction recoveries were greater than 71% and accuracy(relative recovery) was from 89% to 137% for all analytes, except endogenous bile acids. This validated method was successfully applied to the first pharmacokinetic study of CFA, CHA, BA, UDCA and CDCA in rat plasma after intravenous administration of TRQ.

关键词： Tanreqing Injection Flavones Phenolic acids Bile acids Pharmacokinetics

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Kinetic Model of ε-Cu Particle Dissolution in Welding-Induced HAZ of Copper-Containing Steel

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Journal of Iron and Steel Research International 2008年第5期15卷 66-69页

作者： WANG Qing-feng chai feng CAI Jian-wei PAN Tao SU Hang State Key Laboratory of Metastable Materials Technology and Science Yanshan University Qinhuangdao 066004 Hebei China Division of Structural Material Research Central Iron and Steel Research Institute Beijing 100081 China College of Materials Science and Engineering Shanghai Jiaotong University Shanghai 200030 China

The kinetics of ε-Cu particle dissolution in the matrix of heat affected zone （HAZ） during welding of a copper-containing steel was determined by assembling the welding temperature-time program into a modified Whelan＇s solution. The particle dissolution dependence on the degree of ＂superheating＂ above the equilibrium transformation is demonstrated from the model. In terms of volume fraction of particle dissolution, the HAZ may he classified into three zones, including the undissolving zone, the partially dissolving zone, and the completely dissolving zone, respectively. The numerical solution was in good agreement with the experimental examination finding. The results of model can be used to quantitatively map the ε-Cu dissolution zone dependence on the peak temperature of welding thermal cycles and understand the evolution of this transformation during welding.

关键词： ε-Cu particle dissolution kinetics welding steel

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Nucleation Behavior Analysis of Intragranular Acicular Ferrite in a Ti-killed C-Mn Steel

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Journal of Iron and Steel Research International 2014年第3期21卷 369-374页

作者： feng chai Hang SU Cai-fu YANG Dong-mei XUE Division of Structural Material Central Iron and Steel Research Institute

By using a Gleeble 350013 thermo-mechanical simulator, the nucleation behavior of intragranular acicular ferrites （IAF） was studied in a Ti-killed C-Mn steel. During continuous cooling transformation, the allotriomorphic ferrite （AF） and ferrite side plate （FSP） microstructures grew more rapidly with the temperature decreasing from 800 to 650 ℃, and the IAF microstructure was dominant within austenite grain with further cooling to 600 ℃. The diffusion bonding experiment and the effect of C, Mn and Si concentrations on the Ao3 temperature by thermodynam- ic calculation confirm that Ti2O3 itself absorbs neighboring Mn atoms to form Mn-depleted zone （MDZ）, which pro- motes the nucleation of IAF microstructure effectively. High temperature holding tests indicate that the nucleation potential of IAF microstructure was lowered in the Ti-killed C-Mn steel when it was treated at high temperature （1250 ℃ ） for a longer time, which is attributed to the saturated absorption degree of Mn atoms by titanium oxide.

关键词： intragranular aeicular ferrite Ti-killed C-Mn steel Ti2O3 Mn depleted zone

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Corrosion behavior of low alloy steel for cargo oil tank under upper deck conditions

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Journal of Iron and Steel Research International 2018年第1期25卷 120-130页

作者： Hao Li feng chai Cai-fu Yang Chao Li Xiao-bing Luo Central Iron and Steel Research Institute Beijing 100081China Qingdao NCS Testing Protection Technology Co. Ltd.Qingdao 266071 Shandong China

A simulated corrosion test apparatus was used to investigate the corrosion behavior of a low alloy steel under simulated upper deck conditions in a cargo oil tank. The estimated corrosion loss of conventional E36 class ship plate steel is 4.27 mm, which is clearly inadequate compared with the standard adopted by International Maritime Organization. Outer rust layer of specimens starts to peel off after 77 days and becomes fragmented after 98 days. X-ray diffraction, scanning electron micros- copy, and Raman spectroscopy revealed that the resulting rust is composed of σ-FeOOH （the main protective phase）, Fe2O3, FeS, elemental S, and FeSO4. FeSO4 in the interface of the base and rust layer leads to localized corrosion. Elemental sulfur forms on the surface of σ-FeOOH, and the quantity and size thereof increase with increasing corrosion time. Furthermore, layered elemental sulfur promotes fracture and peels off the rust layer.

关键词： Low alloy steel Cargo oil tank Upper deck Corrosion film Elemental sulfur

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