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Solving Interface Problems of the Helmholtz Equation by Immersed Finite Element Methods 预览
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作者 Tao Lin Yanping Lin Qiao Zhuang 《应用数学与计算数学学报(英文)》 2019年第2期187-206,共20页
This article reports our explorations for solving interface problems of the Helmholtz equation by immersed finite elements (IFE) on interface independent meshes. Two IFE methods are investigated: the partially penaliz... This article reports our explorations for solving interface problems of the Helmholtz equation by immersed finite elements (IFE) on interface independent meshes. Two IFE methods are investigated: the partially penalized IFE (PPIFE) and discontinuous Galerkin IFE (DGIFE) methods. Optimal convergence rates are observed for these IFE methods once the mesh size is smaller than the optimal mesh size which is mainly dictated by the wave number. Numerical experiments also suggest that higher degree IFE methods are advantageous because of their larger optimal mesh size and higher convergence rates. 展开更多
关键词 HELMHOLTZ interface problems Immersed FINITE ELEMENT (IFE) METHODS HIGHER degree FINITE ELEMENT METHODS
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Sentiment Analysis of Japanese Tourism Online Reviews
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作者 Chuanming Yu Xingyu Zhu +2 位作者 Bolin Feng Lin Cai Lu An 《数据与情报科学学报:英文版》 CSCD 2019年第1期89-113,共25页
Purpose: Online reviews on tourism attractions provide important references for potential tourists to choose tourism spots. The main goal of this study is conducting sentiment analysis to facilitate users comprehendin... Purpose: Online reviews on tourism attractions provide important references for potential tourists to choose tourism spots. The main goal of this study is conducting sentiment analysis to facilitate users comprehending the large scale of the reviews, based on the comments about Chinese attractions from Japanese tourism website 4Travel.Design/methodology/approach: Different statistics- and rule-based methods are used to analyze the sentiment of the reviews. Three groups of novel statistics-based methods combining feature selection functions and the traditional term frequency-inverse document frequency (TF-IDF) method are proposed. We also make seven groups of different rules-based methods. The macro-average and micro-average values for the best classification results of the methods are calculated respectively and the performance of the methods are shown.Findings: We compare the statistics-based and rule-based methods separately and compare the overall performance of the two method. According to the results, it is concluded that the combination of feature selection functions and weightings can strongly improve the overall performance. The emotional vocabulary in the field of tourism (EVT), kaomojis, negative and transitional words can notably improve the performance in all of three categories. The rule-based methods outperform the statistics-based ones with a narrow advantage.Research limitation: Two limitations can be addressed: 1) the empirical studies to verify the validity of the proposed methods are only conducted on Japanese languages;and 2) the deep learning technology is not been incorporated in the methods.Practical implications: The results help to elucidate the intrinsic characteristics of the Japanese language and the influence on sentiment analysis. These findings also provide practical usage guidelines within the field of sentiment analysis of Japanese online tourism reviews.Originality/value: Our research is of practicability. Currently, there are no studies that focus on the sentiment analysis of Ja 展开更多
关键词 SENTIMENT analysis JAPANESE REVIEWS RULE-BASED METHODS Statistics-based METHODS TOURISM REVIEWS
Research advances in the detection of miRNA 预览
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作者 Jiawei Ye Mingcheng Xu +2 位作者 Xueke Tian Sheng Cai Su Zeng 《药物分析学报:英文版》 CAS CSCD 2019年第4期217-226,共10页
MicroRNAs (miRNAs) are a family of endogenous, small (approximately 22 nucleotides in length), noncoding, functional RNAs. With the development of molecular biology, the research of miRNA biological function has attra... MicroRNAs (miRNAs) are a family of endogenous, small (approximately 22 nucleotides in length), noncoding, functional RNAs. With the development of molecular biology, the research of miRNA biological function has attracted significant interest, as abnormal miRNA expression is identified to contribute to serious human diseases such as cancers. Traditional methods for miRNA detection do not meet current demands. In particular, nanomaterial-based methods, nucleic acid amplification-based methods such as rolling circle amplification (RCA), loop-mediated isothermal amplification (LAMP), strand-displacement amplification (SDA) and some enzyme-free amplifications have been employed widely for the highly sensitive detection of miRNA. MiRNA functional research and clinical diagnostics have been accelerated by these new techniques. Herein, we summarize and discuss the recent progress in the development of miRNA detection methods and new applications. This review will provide guidelines for the development of follow-up miRNA detection methods with high sensitivity and specificity, and applicability to disease diagnosis and therapy. 展开更多
关键词 MicroRNAs DETECTION method AMPLIFICATION strategies Nanomaterial-based METHODS Nucleic acid amplification-based METHODS
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The Cauchy problem for a class of nonlinear degenerate parabolic-hyperbolic equations
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作者 Hua Chen Jinpeng Zhan Xin Hu 《中国科学:数学英文版》 SCIE CSCD 2019年第5期839-852,共14页
In this article, we prove a general existence theorem for a class of nonlinear degenerate parabolichyperbolic equations. Since the regions of parabolicity and hyperbolicity are coupled in a way that depends on the sol... In this article, we prove a general existence theorem for a class of nonlinear degenerate parabolichyperbolic equations. Since the regions of parabolicity and hyperbolicity are coupled in a way that depends on the solution itself, there is almost no hope of decoupling the regions and then taking into account the parabolic and the hyperbolic features separately. The existence of solutions can be obtained by ?nding the limit of solutions for the regularized equation of strictly parabolic type. We use the energy methods and vanishing viscosity methods to prove the local existence and uniqueness of solution. 展开更多
关键词 parabolic-hyperbolic equations energy METHODS VANISHING VISCOSITY METHODS
Advances in Studies on Extraction Methods and Physiological Activities of Jujube Flavonoids 预览
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作者 Zhaoying ZHANG Ya’nan ZHANG Jing HAN 《药用植物研究(英文版)》 2019年第3期8-10,共3页
Jujube is rich in nutrients and functional active ingredients. For example,jujube flavonoids have significant anti-oxidation,anticancer,antibacterial and anti-inflammatory functions. This paper elaborated the advances... Jujube is rich in nutrients and functional active ingredients. For example,jujube flavonoids have significant anti-oxidation,anticancer,antibacterial and anti-inflammatory functions. This paper elaborated the advances in the studies about the extraction methods,purification methods,antioxidant properties,stability and antibacterial effects of jujube flavonoids,in order to provide a certain reference for the study of jujube flavonoids. 展开更多
关键词 JUJUBE Extraction METHODS Determination METHODS ANTI-OXIDANT activity
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Efficient reinforcement learning in continuous state and action spaces with Dyna and policy approximation
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作者 Shan ZHONG Quan LIU +1 位作者 Zongzhang ZHANG Qiming FU 《中国计算机科学前沿:英文版》 SCIE EI CSCD 2019年第1期106-126,共21页
Dyna is an effective reinforcement learning (RL) approach that combines value function evaluation with model learning.However,existing works on Dyna mostly discuss only its efficiency in RL problems with discrete acti... Dyna is an effective reinforcement learning (RL) approach that combines value function evaluation with model learning.However,existing works on Dyna mostly discuss only its efficiency in RL problems with discrete action spaces.This paper proposes a novel Dyna variant,called Dyna-LSTD-PA,aiming to handle problems with continuous action spaces.Dyna-LSTD-PA stands for Dyna based on least-squares temporal difference (LSTD)and policy approximation.Dyna-LSTD-PA consists of two simultaneous,interacting processes.The learning process determines the probability distribution over action spaces using the Gaussian distribution;estimates the underlying value function,policy,and model by linear representation;and updates their parameter vectors online by LSTD(,t).The planning process updates the parameter vector of the value function again by using ofttine LSTD(2).Dyna-LSTD-PA also uses the Sherman-Morrison formula to improve the efficiency of LSTD(,t),and weights the parameter vector of the value function to bring the two processes together.Theoretically,the global error bound is derived by considering approximation,estimation,and model errors.Experimentally,Dyna-LSTD-PA outperforms two representative methods in terms of convergence rate,success rate,and stability performance on four benchmark RL problems. 展开更多
关键词 problem solving control METHODS HEURISTIC SEARCH METHODS dynamic PROGRAMMING
MATERIALS AND METHODS 预览
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《水稻科学:英文版》 CSCD 2019年第3期I0006-I0007,共2页
Rice germplasm A total of 208 indica P/TGMS lines were selected for analysis from the National Mid-term Genebank for Rice, Hangzhou, China (Supplemental Table 2), and 100 typical indica and 100 japonica accessions to ... Rice germplasm A total of 208 indica P/TGMS lines were selected for analysis from the National Mid-term Genebank for Rice, Hangzhou, China (Supplemental Table 2), and 100 typical indica and 100 japonica accessions to identify the indica/japonica component of them were also from the National Mid-term Genebank for Rice, Hangzhou, China (Supplemental Table 5). 展开更多
关键词 MATERIALS METHODS RICE
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Mobility control of unmanned aerial vehicle as communication relay in airborne multi-user systems
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作者 Gaofeng WU Xiaoguang GAO +2 位作者 Xiaowei Fu Kaifang WAN Ruohai DI 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第6期1520-1529,共10页
In this paper, a model-based adaptive mobility control method for an Unmanned Aerial Vehicle(UAV) acting as a communication relay is presented, which is intended to improve the network performance in airborne multi-us... In this paper, a model-based adaptive mobility control method for an Unmanned Aerial Vehicle(UAV) acting as a communication relay is presented, which is intended to improve the network performance in airborne multi-user systems. The mobility control problem is addressed by jointly considering unknown Radio Frequency(RF) channel parameters, unknown multi-user mobility, and non-available Angle of Arrival(AoA) information of the received signal. A Kalman filter and a least-square-based estimation algorithm are used to predict the future user positions and estimate the RF channel parameters between the users and the UAV, respectively. Two different relay application cases are considered: end-to-end and multi-user communications. A line search algorithm is proposed for the former, with its stability given and proven, whereas a simplified gradient-based algorithm is proposed for the latter to provide a target relay position at each decision time step, decreasing the two-dimensional search to a one-dimensional search. Simulation results show that the proposed mobility control algorithms can drive the UAV to reach or track the optimal relay position movement, as well as improving network performance. The proposed method reflects the properties of using different metrics as objective network performance functions. 展开更多
关键词 Channel estimation GRADIENT methods MOTION control Optimization RELAY Unmanned AERIAL vehicle WIRELESS networks
Kinematics-based four-state trajectory tracking control of a spherical mobile robot driven by a 2-DOF pendulum
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作者 Wei LI Qiang ZHAN 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第6期1530-1540,共11页
Spherical mobile robot has compact structure, remarkable stability, and flexible motion,which make it have many advantages over traditional mobile robots when applied in those unmanned environments, such as outer plan... Spherical mobile robot has compact structure, remarkable stability, and flexible motion,which make it have many advantages over traditional mobile robots when applied in those unmanned environments, such as outer planets. However, spherical mobile robot is a special highly under-actuated nonholonomic system, which cannot be transformed to the classic chained form. At present, there has not been a kinematics-based trajectory tracking controller which could track both the position states and the attitude states of a spherical mobile robot. In this paper, the four-state(two position states and two attitude states) trajectory tracking control of a type of spherical mobile robot driven by a 2-DOF pendulum was studied. A controller based on the shunting model of neurodynamics and the kinematic model was deduced, and its stability was demonstrated with Lyapunov’s direct method. The control priorities of the four states were allocated according to the magnification of each state tracking error in order to firstly ensure the correct tracking of the position states. The outputs(motor speeds) of the controller were regulated according to the maximum speeds and the maximum accelerations of the actuation motors in order to solve the speed jump problem caused by initial state errors, and continuous and bounded outputs were obtained. The effectiveness including the anti-interference ability of the proposed trajectory tracking controller was verified through MATLAB simulations. 展开更多
关键词 KINEMATICS Lyapunov methods NEURODYNAMICS NONHOLONOMIC systems Spherical mobile robot Trajectory tracking
浅谈蛇腹折折纸技术在服装设计上的创新应用 预览
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作者 杜亦雯 王文 《科技视界》 2019年第14期17-18,48共3页
随着时代发展,人们更加追求个性化的时装。服装设计元素多种多样,所以我们需要挖掘时装的新颖表现形式,灵感来源于身边的万物。折纸,这一表现形式已登上国际舞台,并被许多服装设计师所应用,但它的趣味性和表现手法还有更多探索的空间。... 随着时代发展,人们更加追求个性化的时装。服装设计元素多种多样,所以我们需要挖掘时装的新颖表现形式,灵感来源于身边的万物。折纸,这一表现形式已登上国际舞台,并被许多服装设计师所应用,但它的趣味性和表现手法还有更多探索的空间。本文以蛇腹折折纸元素为切入点,阐述折纸与服装立体造型间的关系,介绍各种折纸工艺的分类及方法。研究蛇腹折折纸方法,分析蛇腹折折纸形态对应不同面料的表达效果,最终将折纸元素应用到服装设计中。 展开更多
关键词 折纸 蛇腹折 立体造型 方法 创新应用
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精准扶贫视域下大学生精准资助的方法研究——基于贫困生认定的满意度调查 预览
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作者 杨潇 项昱 《黑河学院学报》 2019年第4期86-88,共3页
党的十九大报告中指出,坚决打赢脱贫攻坚战,要坚持精准扶贫,要做到脱真贫、真脱贫。目前,高校要做到精准资助,关键是把好家庭经济困难学生认定“第一关”。以新时代精准资助的挑战与机遇为出发点,分析时代更迭中涌现出的“焦点”问题。... 党的十九大报告中指出,坚决打赢脱贫攻坚战,要坚持精准扶贫,要做到脱真贫、真脱贫。目前,高校要做到精准资助,关键是把好家庭经济困难学生认定“第一关”。以新时代精准资助的挑战与机遇为出发点,分析时代更迭中涌现出的“焦点”问题。立足于问题解决方法,实践总结以“全班动员,民主督导”为理念的“四新四全法”,力图达到全班级动员、全方面了解、全过程合理、全部结果认可的新格局。并通过调查统计,完善“精准度”的效能,为高校把好“第一关”提供了方法上的借鉴。 展开更多
关键词 精准资助 精准扶贫 方法 研究
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林区进行森林区划的探究 预览
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作者 高宏 《林业勘查设计》 2019年第2期14-15,共2页
森林区划作为森林经营管理的关键内容,对林区森林进行合理区划是林业资源永续利用发展的基础。为了能够真正实现森林资源的可持续开发与利用,对森林区划进行深入研究是非常必要的。
关键词 森林区划 方法 研究
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促进供电营销规范,强化供电监管能力 预览
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作者 张建平 田军 张震 《电力系统装备》 2019年第10期186-187,共2页
本文首先分析了目前供电企业在供电营销工作方面存在的问题,然后根据这些问题有针对性地提出了一些促进供电企业供电营销规范、强化供电监管能力的方法,希望可以为供电企业提升营销能力和监管能力提供帮助.
关键词 供电企业 营销 监管 方法
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Reflection on ELT Methods and Principles from the Perspective of“Post-Method”Framework 预览
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作者 LUO Yuan 《海外英语》 2019年第14期270-272,共3页
Over the past decades,the research in ELT methods has already experienced an ongoing transition from method-based pedagogy to post-method pedagogy.With regard to various method-based pedagogy,which is the best and app... Over the past decades,the research in ELT methods has already experienced an ongoing transition from method-based pedagogy to post-method pedagogy.With regard to various method-based pedagogy,which is the best and appropriate method for TEFL in China has been still a controversial and vital issue.By the reflection and critical analysis of my own experience as an EFL learner and of teaching methods and principles in ELT class as a college teacher,this paper mainly demonstrates there is no one so called‘best’or‘right’teaching methods for all from the perspective of Post-method framework which reflects a theoretical construct for teachers to effectively develop a systematic,and coherent pedagogy in their teaching context,aims to provide more instructive reference for ELT and English teachers’development in China. 展开更多
关键词 ELT methods teaching principles post-method pedagogy REFLECTION
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口译教学训练评价中形成性评价的应用 预览
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作者 闫波 《教学研究》 2019年第3期80-84,共5页
近年来,作为口译教学和翻译学研究中的一个难题,口译教学训练评价备受关注。在口译教学训练中恰当地运用形成性评价、综合成果评估与过程评估,不仅能够加强教师和学生对整个学习过程的监督和管理,还能增强教学的启发性和学生的自主性,... 近年来,作为口译教学和翻译学研究中的一个难题,口译教学训练评价备受关注。在口译教学训练中恰当地运用形成性评价、综合成果评估与过程评估,不仅能够加强教师和学生对整个学习过程的监督和管理,还能增强教学的启发性和学生的自主性,从而有效地促进教学发展。通过对口译教学训练评价研究的回顾,探讨了形成性评价在口译教学训练中应用的基础和要求,并详细阐述了其实施途径、方法与效果。 展开更多
关键词 口译教学 形成性评价 应用 途径 方法 效果
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构建倾听式课堂的教学策略及方法 预览
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作者 杜肖楠 《齐鲁师范学院学报》 2019年第1期20-27,共8页
课堂教学的最高境界是学生能够全程倾听教师的讲课。构建倾听式课堂的基础是提高学生的母语听力水平。听话注意力是整个听话活动的前提和保证。在教学中教师是解决问题的关键,在实践操作层面教师可以采取有效的策略和方法调动学生的听觉... 课堂教学的最高境界是学生能够全程倾听教师的讲课。构建倾听式课堂的基础是提高学生的母语听力水平。听话注意力是整个听话活动的前提和保证。在教学中教师是解决问题的关键,在实践操作层面教师可以采取有效的策略和方法调动学生的听觉,使学生摆脱注意力涣散的听课状态,构建倾听式课堂。 展开更多
关键词 倾听式课堂 教学 策略 方法
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中职物理教学高效课堂构建初探 预览
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作者 杨琪 《科教文汇》 2019年第15期125-126,共2页
近几年来,中职物理教学过程中,越来越多的教研人员意识到引进先进教学理念的重要性与必要性,并在此过程中,不断结合学生个性特点及认知层次,制定针对性的教学方案,以期满足不同学生的学习需求。而本文则主要针对中职物理教学高效课堂的... 近几年来,中职物理教学过程中,越来越多的教研人员意识到引进先进教学理念的重要性与必要性,并在此过程中,不断结合学生个性特点及认知层次,制定针对性的教学方案,以期满足不同学生的学习需求。而本文则主要针对中职物理教学高效课堂的构建方式进行分析,并提出了见解与思考,首先探讨了影响中职物理高效课堂构建主要因素,而后提出了构建策略。 展开更多
关键词 中职 物理 高效课堂 构建 方法
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倾向性评分方法及其应用
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作者 黄丽红 陈峰 《中华预防医学杂志》 CAS CSCD 北大核心 2019年第7期752-756,共5页
倾向性评分作为一种对多个协变量进行调整的分析策略,在观察性疗效比较研究中的应用越来越广泛。本文从基本原理、案例分析、软件实现等方面对该方法进行详细介绍,以期读者对倾向性评分方法有所了解,在科研工作中能正确应用,提高数据使... 倾向性评分作为一种对多个协变量进行调整的分析策略,在观察性疗效比较研究中的应用越来越广泛。本文从基本原理、案例分析、软件实现等方面对该方法进行详细介绍,以期读者对倾向性评分方法有所了解,在科研工作中能正确应用,提高数据使用效率和统计分析水平。 展开更多
关键词 倾向评分 混杂因素(流行病学) 方法 观察性疗效比较研究
浅析《傅青主女科》水火既济之治法 预览
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作者 洪逸萍 《中医文献杂志》 2019年第4期28-30,共3页
文章通过对《傅青主女科》辨证及用药的研究,从水火既济的概念、方法、枢纽、时间四个方面阐述,探究傅氏学术思想,为临床治疗提供借鉴。
关键词 傅青主女科 水火既济 方法 枢纽 时机
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提高地方师范院校结构化学教学趣味性的几项举措 预览
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作者 谢木标 《化工高等教育》 2019年第4期101-105,共5页
针对地方师范院校的教学实际,本文从故事引导、交叉学科结合、精简内容和因材施教、结构模型和软件利用、理论联系实际五个方面介绍了如何提高结构化学教学的趣味性,从而培养学生学习兴趣,提升教学质量。
关键词 结构化学 趣味性 举措
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