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Structural Dependence Learning Based on Self-attention for Face Alignment

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Machine Intelligence Research 2024年第3期21卷 514-525页

作者： Biying Li Zhiwei liu Wei zhou Haiyun Guo Xin Wen Min Huang jinqiao Wang Foundation Model Research Center Institute of AutomationChinese Academy of SciencesBeijing100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing100083China Alpha(Beijing)Private Equity Beijing100083China School of Computer Science National University of Defense TechnologyChangsha410073China

Self-attention aggregates similar feature information to enhance the features. However, the attention covers nonface areas in face alignment, which may be disturbed in challenging cases, such as occlusions, and fails to predict landmarks. In addition, the learned feature similarity variance is not large enough in the experiment. To this end, we propose structural dependence learning based on self-attention for face alignment (SSFA). It limits the self-attention learning to the facial range and adaptively builds the significant landmark structure dependency. Compared with other state-of-the-art methods, SSFA effectively improves the performance on several standard facial landmark detection benchmarks and adapts more in challenging cases.

关键词： Computer vision face alignment self-attention facial structure contextual information

Heredity in the Microstructure and Mechanical Properties of Hot-rolled Spring Steel Wire 60Si2MnA during Heat Treatment Process

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Journal of Materials Science & Technology 2013年第1期29卷 82-88页

作者： Chaolei Zhang Leyu zhou yazheng liu School of Materials Science and Engineering University of Science and Technology Beijing

Heredity in the microstructure and mechanical properties of hot-rolled spring steel wire 60Si2MnA during heat treatment process was investigated comprehensively. The steel was isothermally transformed to obtain various hot-rolled microstructure （pearlite fineness within the range of 140-510 nm） and mechanical properties, and followed by some quenching-tempering treatment. Afterwards, microstructure was characterized by optical microscopy, scanning electron microscopy and quantitative metallography, and mechanical properties were determined by tensile test. The results indicated that the hot-rolled microstructure with a coarsen pearlite structure had been changed after reheating, to a austenite microstructure with bigger and more uneven grain size, and finally to a coarsen tempered microstructure. And the average austenite grain size and standard deviation of its distribution in quenched microstructure were observed to depend linearly on the interlamellar spacing in hot-rolled microstructure. Besides, to obtain a good combination of the final strength and plasticity, an optimum value range （190-280 nm） of the interlamellar spacing had been determined for the interlamellar spacing in hot-rolled microstructure.

关键词： Spring steel Hot-rolling Heat treatment Microstructure Mechanical properties Heredity

Simulation of annealing process effect on texture evolution of deep-drawing sheet Stl5

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Journal of University of Science and Technology Beijing 2005年第6期12卷 512-516页

作者： Jinghong Sun yazheng liu Leyu zhou Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

A two-dimensional cellular automaton method was used to simulate grain growth during the recrystallization annealing of deep-drawing sheet St 15, taking the simulated result of recrystallization and the experimental result of the annealing texture of deepdrawing sheet St15 as the initial condition and reference. By means of computer simulation, the microstructures and textures of different periods of grain growth were predicted. It is achieved that the grain size, shape and texture become stable after the grain growth at a constant temperature of 700℃ for 10 h, and the advantaged texture components { 111 } 〈 110 〉 and { 111 } 〈 112〉 are dominant.

关键词： cellular automaton deep-drawing sheet texture simulation

Heat Treatment Properties of 42CrMo Steel for Bearing Ring of Varisized Shield Tunneling Machine

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Acta Metallurgica Sinica(English Letters) 2014年第3期27卷 383-388页

作者： Bo Jiang Leyu zhou Xinli Wen Chaolei Zhang yazheng liu School of Materials Science and Engineering University of Science and Technology Beijing

The heat treatment properties of 42CrMo steel for bearing ring of varisized shield tunneling machine were investigated by optical microscope （OM）, scanning electron microscope （SEM）, transmission electron microscope （TEM）, and impact tests. The addition of 0.03 wt% C into 42CrMo steel can increase the hardness. But it reduces the impact energy by 46 J because of the appearance of coarser carbides in the matrix and the carbides along the austenite grain boundary. The addition of 0.40 wt% Mn into 42CrMo steel can improve hardenability. However, the toughness of steel is also reduced by 26 J mainly because of the coarsening of carbides and the strengthening of matrix. Both hardenability and toughness of 42CrMo steel can be improved by adding 1.49 wt% Ni and reducing 0.32 wt% Cr. The depth of hardening layer can be raised to 45 mm, and the impact energy at -20 ℃ is 120 J. Thus, it is concluded that a good combination of hardness, hardenability, and toughness of 42CrMo steel can be achieved by alloying with adding some content of C and Ni. Detailed content of C and Ni should be on the requirements of heat treatment properties of steel for bearing ring of varisized shield tunneling machine.

关键词： Shield tunneling machine Bearing ring 42CrMo steel Hardenability Toughness

Microstructure Control of Non-quenched and Tempered CT80Grade Coiled Tubing Steel

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Acta Metallurgica Sinica(English Letters) 2014年第3期27卷 464-468页

作者： Leyu zhou Bo Jiang Mingyang Li Fuchun Yuan Chaolei Zhang yazheng liu School of Materials Science and Engineering University of Science and Technology Beijing

Complex working condition of coiled tube （CT） steel demands high strength and low ratio of yield strength （YS） to tensile strength （TS）. Reasonable microstructure control is a key problem of CT steel. Controlled rolling and controlled cooling experiments were carded out by two kinds of tested steels with different chemical compositions to develop the non-quenched and tempered CT80 steel. Mechanical properties of the tested steels at different processes are all in good agreement with the properties requirement of CT80. Increasing of Mo and Nb contents improves transformation of acicular ferrite and martensite-austenite （M-A） islands. 4 vol% of fine M/A islands increase TS and decreases ratio of YS/ TS, Cooling rate increasing also improves acicular ferrite transformation and enhances TS, but has little effect on ratio of YS/TS. To meet the requirement of high strength and low ratio of YS/TS, optimized complex microstructure of the CT80 steel is composed of acicular ferrite, about 30 vol% of bainite and 4 vol% of M-A islands.

关键词： Coiled tube M-A islands Acicular ferrite Mechanical properties

多参数影像组学模型对成人型弥漫性胶质瘤分子亚型的预测价值

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中华神经外科杂志 2024年第1期40卷 60-66页

作者：季玉陈马泽宇阎静郭杨于银辉傅京赵南南周金桥刘献志张振宇郑州大学第一附属医院神经外科郑州450052 郑州大学第一附属医院磁共振科郑州450052 河南省人民医院神经外科郑州450003

目的探讨基于MRI图像构建多参数影像组学模型对成人型弥漫性胶质瘤异柠檬酸脱氢酶(IDH)突变型、IDH野生型、IDH突变1p/19q共缺失型分子亚型的预测价值。方法回顾性收集2011年1月至2021年9月郑州大学第一附属医院神经外科(数据集1:465例... 详细信息

目的探讨基于MRI图像构建多参数影像组学模型对成人型弥漫性胶质瘤异柠檬酸脱氢酶(IDH)突变型、IDH野生型、IDH突变1p/19q共缺失型分子亚型的预测价值。方法回顾性收集2011年1月至2021年9月郑州大学第一附属医院神经外科(数据集1:465例)和河南省人民医院神经外科(数据集2:137例)行肿瘤切除且术后病理学诊断为成人型弥漫性胶质瘤患者的临床及术前影像学资料。提取并筛选出最优的影像组学特征,使用Boruta软件包、随机森林等组合算法构建影像组学模型。将数据集1按7:3的比例随机分为训练集与内部验证集进行机器学习,并对数据集2行独立外部验证(外部验证集)。绘制受试者工作特征(ROC)曲线并计算曲线下面积(AUC),以评估多参数影像组学模型对成人型弥漫性胶质瘤分子亚型的预测效能。结果数据集1中训练集332例,内部验证集133例,两者的性别、年龄、胶质瘤分子亚型、世界卫生组织分级等临床资料的差异均无统计学意义(均P>0.05);数据集1与数据集2患者上述临床资料的差异均无统计学意义(均P>0.05)。影像组学共筛选出8个纹理特征和13个强度特征与成人型弥漫性胶质瘤的分子亚型具有显著相关性。内部验证集中,IDH突变型、IDH野生型、IDH突变1p/19q共缺失型胶质瘤的AUC分别为0.81、0.86、0.85,灵敏度分别为89.5%、69.4%、75.0%,特异度分别为63.2%、91.4%、82.9%;外部验证集中,IDH突变型、IDH野生型、IDH突变1p/19q共缺失型胶质瘤的AUC分别为0.76、0.82、0.81,灵敏度分别为75.0%、67.3%、72.2%,特异度分别为64.6%、78.6%、79.8%。结论多参数影像组学模型对成人型弥漫性胶质瘤分子亚型的分类具有较高的预测价值。

关键词：神经胶质瘤异柠檬酸脱氢酶磁共振成像预测影像组学分子亚型

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高速线材82B控制冷却线的数学模型和应用

特殊钢 2006年第5期27卷 12-14页

作者：徐进桥刘雅政周淑梅北京科技大学材料科学与工程学院北京100083

采用商用有限元软件Marc，模拟研究了成分（％）为0．80-0．82C，0．6-0．9Mn，0．016V成品规格Ф12．5mm高速线材82B的62．7m控制冷却线水冷段和风冷段过程的钢材温度的数学模型。模拟计算的结果与现场实测值对比表明，其误差〈25℃。

关键词：高碳钢高速线材控制冷却数学模型

超超临界锅炉水冷壁近壁面颗粒特性及冲刷磨损研究

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智能计算机与应用 2024年第5期14卷 136-143页

作者：周钱钱进王康林志恒邓传记殷金桥刘动力贵州大学电气工程学院贵阳550025 国家电投集团贵州金元茶园发电有限责任公司贵州毕节551700 中国电力工程顾问集团中南电力设计院有限公司武汉430060

CFB锅炉水冷壁冲刷、磨损、减薄及保管问题造成了机组运行安全性、可靠性降低,为研究超超临界参数锅炉水冷壁近壁面颗粒特性,通过数值模拟的方法对BMCR工况下炉膛整体颗粒特性、不同粒径和不同冲击角下水冷壁墙角区域颗粒特性进行分析... 详细信息

CFB锅炉水冷壁冲刷、磨损、减薄及保管问题造成了机组运行安全性、可靠性降低,为研究超超临界参数锅炉水冷壁近壁面颗粒特性,通过数值模拟的方法对BMCR工况下炉膛整体颗粒特性、不同粒径和不同冲击角下水冷壁墙角区域颗粒特性进行分析。研究结果表明:BMCR工况下,炉膛颗粒体积分数呈“马鞍形”分布;颗粒在水冷壁墙角区域向下运动时,墙角中心区域和水冷壁管迎风侧的颗粒体积分数更高,在墙角内测,颗粒体积分数对相对磨损量影响更大,在墙角外侧颗粒速度对相对磨损量影响更大;颗粒冲击角度越大,获得的高水平方向速度分量越大,受到来自炉膛中心流体的裹挟作用也越大,墙角内侧更容易形成高速度区域,水冷壁迎风侧壁面整体相对磨损量大于背风侧。

关键词：超超临界参数水冷壁颗粒特性相对磨损量

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23CrNi3Mo钢动态再结晶行为和组织演变研究

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材料科学与工艺 2014年第1期22卷 42-47页

作者：闫永明刘雅政周乐育徐盛北京科技大学材料科学与工程学院北京100083

利用Gleeble-1500热模拟试验机进行单道次热压缩变形,通过控制变形温度(900,950,1 000,1 050℃)和应变速率(0.01,0.1和1 s-1)研究了23CrNi3Mo钢的动态再结晶行为,分析了变形温度、应变速率对动态再结晶行为和组织演变的影响.结果表明:23... 详细信息

利用Gleeble-1500热模拟试验机进行单道次热压缩变形,通过控制变形温度(900,950,1 000,1 050℃)和应变速率(0.01,0.1和1 s-1)研究了23CrNi3Mo钢的动态再结晶行为,分析了变形温度、应变速率对动态再结晶行为和组织演变的影响.结果表明:23CrNi3Mo钢动态再结晶的再结晶激活能为293.23 kJ/mol;采用θ-σ模型较精确地获得了发生动态再结晶的临界应变与峰值应变,并确定了其平均比值εc/εp=0.63;确定了材料常数和热变形本构方程.通过对热模拟实验数据的分析和显微组织观察,建立了不同变形条件下动态再结晶模型和晶粒尺寸模型.

关键词： 23CrNi3Mo 应变速率变形温度动态再结晶晶粒尺寸