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Job schedulers for Big data processing in Hadoop environment： testing real-life schedulers using benchmark programs

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Digital Communications and Networks 2017年第4期3卷 260-273页

作者： Mohd Usama mengchen liu Min Chen Embedded and Pervasive Computing(EPIC) Lab School of Computer Science and Technology Huazhong University of Science and Technology wuhon 430074 China

At present, big data is very popular, because it has proved to be much successful in many fields such as social media, E-commerce transactions, etc. Big data describes the tools and technologies needed to capture, manage, store, distribute, and analyze petabyte or larger-sized datasets having different structures with high speed. Big data can be structured, unstructured, or semi structured. Hadoop is an open source framework that is used to process large amounts of data in an inexpensive and efficient way, and job scheduling is a key factor for achieving high performance in big data processing. This paper gives an overview of big data and highlights the problems and challenges in big data. It then highlights Hadoop Distributed File System （HDFS）, Hadoop MapReduce, and various parameters that affect the performance of job scheduling algorithms in big data such as Job Tracker, Task Tracker, Name Node, Data Node, etc. The primary purpose of this paper is to present a comparative study of job scheduling algorithms along with their experimental results in Hadoop environment. In addition, this paper describes the advantages, disadvantages, features, and drawbacks of various Hadoop job schedulers such as FIFO, Fair, capacity, Deadline Constraints, Delay, LATE, Resource Aware, etc, and provides a comparative study among these schedulers.

关键词： Big Data Hadoop MapReduce HDFS Scheduler Classification Locality Benchmark

A survey of visual analytics techniques for machine learning

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Computational Visual Media 2021年第1期7卷 3-36页

作者： Jun Yuan Changjian Chen Weikai Yang mengchen liu Jiazhi Xia Shixia liu BNRist Tsinghua UniversityBeijing 100086China Microsoft Redmond 98052USA Central South University Changsha 410083China

Visual analytics for machine learning has recently evolved as one of the most exciting areas in the field of *** better identify which research topics are promising and to learn how to apply relevant techniques in visual analytics,we systematically review259 papers published in the last ten years together with representative works before *** build a taxonomy,which includes three first-level categories:techniques before model building,techniques during modeling building,and techniques after model *** category is further characterized by representative analysis tasks,and each task is exemplified by a set of recent influential *** also discuss and highlight research challenges and promising potential future research opportunities useful for visual analytics researchers.

关键词： visual analytics machine learning data quality feature selection model understanding content analysis

Towards better analysis of machine learning models:A visual analytics perspective

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Visual Informatics 2017年第1期1卷 48-56页

作者： Shixia liu Xiting Wang mengchen liu Jun Zhu Tsinghua University BeijingChina

Interactive model analysis,the process of understanding,diagnosing,and refining a machine learning model with the help of interactive visualization,is very important for users to efficiently solve real-world artificial intelligence and data mining *** advances in big data analytics have led to a wide variety of interactive model analysis *** this paper,we present a comprehensive analysis and interpretation of this rapidly developing ***,we classify the relevant work into three categories:understanding,diagnosis,and *** category is exemplified by recent influential *** future research opportunities are also explored and discussed.

关键词： Interactive modelanalysis Interactive visualization Machine learning Understanding Diagnosis Refinement

Mapping the antiparallel aligned domain rotation by microwave excitation

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Chinese Physics B 2024年第9期33卷 599-605页

作者： Jing Zhang Yuanzhi Cui Xiaoyu Wang Chuang Wang mengchen liu Jie Xu Kai Li Yunhe Zhao Zhenyan Lu Lining Pan Chendong Jin Qingfang liu Jianbo Wang Derang Cao College of Physics Qingdao UniversityQingdao 266071China National Demonstration Center for Experimental Applied Physics Education Qingdao UniversityQingdao 266071China SKLSM Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China College of Chemistry Chemical Engineering and Resource UtilizationNortheast Forestry UniversityHarbin 150040China Hunan Provincial Key Laboratory of Intelligent Sensors and Advanced Sensor Materials School of Physics and ElectronicsHunan University of Science and TechnologyXiangtan 411201China CAS Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Key Laboratory of Optic-Electronic Information and Materials of Hebei Province Research Center for Computational PhysicsCollege of Physics Science and TechnologyHebei UniversityBaoding 071002China Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education Lanzhou UniversityLanzhou 730000China Key Laboratory of Special Functional Materials and Structural Design Ministry of EducationLanzhou UniversityLanzhou 730000China

The evolution process of magnetic domains in response to external fields is crucial for the modern understanding and application of *** this study,we investigated the domain rotation in stripe domain films of varying thicknesses by examining their response to microwave excitation in four different *** resonance spectra indicate that the rotation field of stripe domain film under an applied magnetic field approaches the field where the resonance mode of sample *** saturation field of the stripe domain film corresponds to the field where the resonance mode disappears when measured in the stripe direction parallel to the microwave magnetic *** results are reproducible and consistent with micromagnetic simulations,providing additional approaches and techniques for comprehending the microscopic mechanisms of magnetic domains and characterizing their rotation.

关键词： stripe domain magnetic film microwave excitation micromagnetic simulation

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新闻数据可视分析系统

计算机辅助设计与图形学学报 2016年第11期28卷 1863-1871页

作者：肖剑楠刘梦尘刘世霞清华大学软件学院北京100084

文中展示了一个具有创新性的新闻可视分析系统——VASNRU.该系统有机地结合了新闻数据收集与可视分析,旨在帮助用户更好地分析与理解新闻数据.该系统首先根据用户想要查询的内容,利用搜索引擎自动地收集一定数量的新闻数据;在此基础上,... 详细信息

文中展示了一个具有创新性的新闻可视分析系统——VASNRU.该系统有机地结合了新闻数据收集与可视分析,旨在帮助用户更好地分析与理解新闻数据.该系统首先根据用户想要查询的内容,利用搜索引擎自动地收集一定数量的新闻数据;在此基础上,自动地对收集到的数据进行预处理,以便进一步进行分析.为了帮助用户更好地分析与理解数据,采用一个可视分析工具(Mutual Ranker)对处理好的数据进行可视分析,采用VASNRU收集并分析了2个真实的新闻数据集,结果验证了其能够方便、高效地收集与分析新闻数据.

关键词：新闻数据数据收集可视分析

High-performance GaSb planar PN junction detector

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Journal of Semiconductors 2024年第9期45卷 48-52页

作者： Yuanzhi Cui Hongyue Hao Shihao Zhang Shuo Wang Jing Zhang Yifan Shan Ruoyu Xie Xiaoyu Wang Chuang Wang mengchen liu Dongwei Jiang Yingqiang Xu Guowei Wang Donghai Wu Zhichuan Niu Derang Cao College of Physics National Demonstration Center for Experimental Applied Physics EducationQingdao UniversityQingdao 266071China Key Laboratory of Optoelectronic Materials and Devices Chinese Academy of SciencesBeijing 100083China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijing 100049China

This paper examines GaSb short-wavelength infrared detectors employing planar PN junctions. The fabrication was based on the Zn diffusion process and the diffusion temperature was optimized. Characterization revealed a 50% cut-off wavelength of 1.73 μm, a maximum detectivity of 8.73 × 10^(10) cm·Hz^(1/2)/W, and a minimum dark current density of 1.02 × 10^(-5) A/cm^(2).Additionally, a maximum quantum efficiency of 60.3% was achieved. Subsequent optimization of fabrication enabled the realization of a 320 × 256 focal plane array that exhibited satisfactory imaging results. Remarkably, the GaSb planar detectors demonstrated potential in low-cost short wavelength infrared imaging, without requiring material epitaxy or deposition.

关键词： antimonide short-wave infrared planar junction zinc diffusion

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气膜孔视觉测量中的坐标系建立与转换

传感技术学报 2019年第10期32卷 1515-1521页

作者：毕超郝雪刘孟晨刘勇北京航空精密机械研究所精密制造技术航空科技重点实验室

为了能够应用所搭建的四轴视觉坐标测量系统对批量气膜孔的分布位置进行检测,结合四轴运动系统与工业相机的特点,开展了将测量数据由图像空间转化到叶片空间过程中的坐标系建立与转换关系研究。在应用过程中,建立了图像像素坐标系、图... 详细信息

为了能够应用所搭建的四轴视觉坐标测量系统对批量气膜孔的分布位置进行检测,结合四轴运动系统与工业相机的特点,开展了将测量数据由图像空间转化到叶片空间过程中的坐标系建立与转换关系研究。在应用过程中,建立了图像像素坐标系、图像物理坐标系、基准坐标系、回转台坐标系和叶片坐标系,并确立了这些坐标系之间的相互转换关系,从而实现了将工业相机所采集到的图像数据转化成物理测量数据,并最终转换到叶片坐标系中。最后,为了验证该方法的正确性和有效性,选取了某个高压涡轮导向叶片作为被测物,首先对其上的一个气膜孔进行了分布位置的多次等精度重复测量实验,检验了该测量系统的重复性精度,而后对该叶片上的一排12个气膜孔进行了测量实验。实验结果表明,本文所提出的坐标系建立与转换方法,可以完成气膜孔分布位置的检测任务,从而为后续与气膜孔的设计数据进行比对并做出评价奠定了坚实基础。

关键词：视觉测量气膜孔坐标系统三坐标测量机

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基于视觉测量的回转轴线标定方法研究

红外与激光工程 2020年第4期49卷 159-166页

作者：毕超郝雪刘孟晨房建国北京航空精密机械研究所精密制造技术航空科技重点实验室北京100076

为了实现高压涡轮叶片上的气膜孔特征的高精高效测量,设计并搭建了一套非接触式的四轴视觉坐标测量系统。针对其中的回转轴线的空间位置标定难题,结合工业影像测头的成像特点,提出了一种基于视觉测量的回转轴线标定方法。在标定过程中,... 详细信息

为了实现高压涡轮叶片上的气膜孔特征的高精高效测量,设计并搭建了一套非接触式的四轴视觉坐标测量系统。针对其中的回转轴线的空间位置标定难题,结合工业影像测头的成像特点,提出了一种基于视觉测量的回转轴线标定方法。在标定过程中,采用了定制的长方体标定块,并通过回转工作台与三坐标测量机之间的配合,使工业影像测头对焦于标定块的表面并采集到其锋利棱边的图像,而后再通过边缘提取、像素距离计算、物理距离转化和代数运算等步骤,最终确定了回转工作台的轴线在机器坐标系中的空间方位。最后,选用一个标称尺寸为80 mm的标准量块作为被测物体,以对标定方法及标定结果进行验证,各次测量结果的误差均小于±0.01 mm,并进行了合成标准不确定度的分析。实验结果表明:文中所提出的回转轴线标定方法能够达到较高的标定精度和较好的重复性,能够满足气膜孔形位参数的检测要求。

关键词：视觉测量三坐标测量机回转工作台气膜孔

动脉粥样硬化斑块的生物力学模型和数值模拟研究

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生物医学工程学杂志 2020年第6期37卷 948-955页

作者：刘梦辰潘霁超蔡彦(综述) 李志勇(审校) 东南大学生物科学与医学工程学院生物力学实验室南京210096

动脉粥样硬化是一个复杂的、多因素作用的病理过程。过去十多年的研究结果表明,动脉粥样硬化易损斑块的发展与其构成组分、形态结构和受力状况密切相关。学者们将医学影像、生物实验、力学建模有机地结合起来,利用生物力学模型研究和分... 详细信息

动脉粥样硬化是一个复杂的、多因素作用的病理过程。过去十多年的研究结果表明,动脉粥样硬化易损斑块的发展与其构成组分、形态结构和受力状况密切相关。学者们将医学影像、生物实验、力学建模有机地结合起来,利用生物力学模型研究和分析影响斑块易损性的相关力学因素。数值模拟能够定量表述斑块内微环境的动态变化,包括细胞和非细胞组分的分布及其受到的周围微环境的调控,从理论上阐释脂质沉积、炎症反应、新生血管等病理过程的相互作用。研究斑块发展病理机制,能够进一步提高人类对心血管疾病的认识,辅助易损斑块的无创检测和早期诊断,并为设计和优化易损斑块的治疗方案提供一定的参考信息。

关键词：动脉粥样硬化生物力学数值模拟易损斑块