PAD Class教学模式对英语专业学生写作焦虑影响的实证研究

本研究以英语专业大一120名学生为实验对象,进行了为期16周的实证研究,以探讨PAD class教学模式对英语专业学生写作焦虑的影响。基于《二语写作焦虑量表》调查问卷结果表明:英语专业学生总体焦虑处于中等焦虑水平,PAD Class能有效降低学生的写作总体焦虑,其中课堂焦虑、构思焦虑、自信焦虑明显降低,但回避焦虑没有达到显著水平;PAD Class模式对高中低不同写作水平学生的写作焦虑都有影响,对中、低水平学生的写作焦虑缓解比对高水平学生的影响效果更明显。

基于IFC的建筑结构设计信息交互框架研究与实现

为了解决基于BIM的建筑与结构设计工作模式中信息交互度低的问题,提出了基于IFC的建筑结构信息交互框架。该框架由4个算法模块、5个步骤组成。借助于IfcOpenShell工具包,用Python语言开发了前两个算法模块即IFC文件优化算法模块和结构信息模型提取算法模块。选取案例模型对所开发算法的有效性进行了验证。验证结果表明:优化算法模块可以有效地过滤IFC文件中的无用信息,查找并删除重复的实体,使IFC文件轻量化,且可间接提高提取算法模块的运行效率;提取算法模块可以准确地从IFC文件中提取结构信息模型,未出现IFC语法错误、构件丢失、构件重叠等情况。IFC文件优化算法模块和结构信息模型提取算法模块的成功开发为信息交互框架的完全实现奠定了基础。

基于IFC标准的机场道面结构信息模型存储与传递方法

为解决机场跑道系统在全生命周期建筑信息模型(BIM)应用中的信息传递和数据交互问题,将工业基础类(IFC)标准在机场跑道系统进行扩展,建立机场道面结构的IFC实体架构,在此基础上创建面向运维应用的刚性道面板实体,并进行几何信息与属性信息的扩展;提出基于IFC的属性信息添加与传递方法,对信息传递过程中的属性信息丢失率进行分析。研究表明:通过建立IFC标准模型,可以实现机场跑道系统的信息传递和数据交互;采用基础模型族扩展法进行机场道面模型传递的属性信息丢失率高达84.21%;采用IFC解析扩展法首次传递可保证信息不丢失,但二次传递信息存在丢失问题;族模型IFC解析扩展法可实现信息首次传递不丢失,二次传递属性信息丢失率低至16.7%,并且采用不同IFC标准版本对模型传递过程中的属性信息丢失率产生较大影响。应用IFC标准进行机场领域扩展具有较高的可行性,所提的信息传递方法可实现机场道面全生命周期信息传递。研究成果可为机场飞行区新IFC实体的扩展提供支持,为机场工程数字化提供技术参考。

基于IFC的轨道交通BIM构件标准库研究

针对轨道交通工程的建筑信息模型(building information modeling,BIM)建模方法不统一、信息不规范,导致BIM模型数据难以在后期有效统一应用的弊端,研究基于工业基础类(industry foundation classes,IFC)标准的轨道交通BIM构件标准库。首先,根据轨道交通工程各专业构件的表达需求,研究构件类型、构件信息的IFC表达,以及适配IFC标准的扩展机制;其次,提出轨道交通BIM构件标准库技术框架,主要包括基础数据层、技术支撑层、应用场景层、用户层;然后,采用国家标准的分类编码方法定义轨道交通各专业BIM构件的分类编码,设计了构件信息模板,规范各专业构件的属性信息及其资源链接方式;最后,研究BIM构件模型的加解密方法,以保障轨道交通工程BIM模型数据的安全性。研究结果表明,通过搭建统一的BIM构件标准库,能够促进参建方采用标准化的BIM构件模型创建轨道交通BIM项目模型,保障BIM模型的规范性。

融合IFC语义信息与几何相似性的BIM构件实例信息提取方法

建筑信息模型(BIM)能够对建筑结构、部件组成及其业务语义属性进行准确表达,在智慧城市时空底板建设及建筑物“规、建、养、运”全生命周期数字化管理中发挥着重要的作用。BIM模型的数量级大、引用关系与层级结构复杂,增加了BIM构件实例信息的提取难度,从而导致目前的CIM平台难以直接利用BIM构件实例信息实现轻量化的数据传输、流畅的可视化及BIM分析计算。针对此问题,本文提出了一种融合IFC语义信息与几何相似性的BIM构件实例信息提取方法,在充分考虑IFC几何引用语义信息的基础上,使用ICP算法和豪斯多夫距离计算几何相似性,实现对BIM构件实例信息的精确提取;此外,还针对BIM场景中常见的拉伸体构件,提出了一种基于特殊拉伸体的实例信息快速提取方法;最后选取了5个不同BIM专业的试验示例数据进行详尽分析。试验结果显示,本文提出的BIM构件实例信息提取方法在各种示例数据中的文件平均压缩率为29.79%,能够显著地减小文件体积;在BIM构件实例信息提取能力方面,实现了79.41%的平均构件实例化率及22.47%的平均实体压缩率,且每个实例化构件平均包含的子构件数量高达49.24。本文方案可以充分提取IFC文件中的BIM构件实例信息,能够为海量BIM模型的轻量化提供强有力的技术支撑。

基于IFC的结构BIM模型创建和数据管理技术研究和实现

结构计算模型与BIM模型的融合是实现BIM在结构工程中全面应用的关键环节,本文研究钢筋混凝土结构计算模型的数据格式,根据计算模型中的构件数据和配筋数据分别生成包含混凝土构件和钢筋的IFC模型,并基于分布式数据库存储完成IFC模型合并以及数据管理的相关技术。基于本文研究成果和开发的相关软件,可以由结构计算模型生成准确的结构BIM模型,该模型可应用于碰撞检测、工程量统计、施工图生成等场景。通过项目应用验证了本文方法的有效性。

Hybrid treatment of varied orthodontic appliances for a patient with skeletal class II and temporomandibular joint disorders:A case report and review of literature

BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a challenge.If TMD symptoms occur during orthodontic treatment,an immediate pause of orthodontic adjustments is recommended;the treatment can resume when the symptoms are managed and stabilized.CASE SUMMARY This case report presents a patient(26-year-old,female)with angle class I,skeletal class II and TMDs.The treatment was a hybrid of clear aligners,fixed appliances and temporary anchorage devices(TADs).After 3 mo resting and treatment on her TMD,the patient’s TMD symptom alleviated,but her anterior occlusion displayed deep overbite.Therefore,the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves.After the levelling,the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion.After careful examination of temporomandibular joints(TMJ)position,the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion.Eventually,the improved facial appearance and relatively stable occlusion were achieved.The 1-year follow-up records showed there was no obvious change in TMJ morphology,and her occlusion was stable.CONCLUSION TMD screening and monitoring is of great clinical importance in the TMD susceptible patients.Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.

基于IFC规范的模型扩展物联数据方法研究

针对建筑行业中海量物联数据传递的问题,提出一种基于IFC规范的模型扩展物联数据方法。将物联数据的数据请求作为IFC模型的附加属性集,与模型中的测点进行绑定,可实现在BIM模型传递的同时将物联数据同步传递。研究内容重点描述了物联监测数据随模型传递的优势,并通过模型扩展物联数据方法定义、原理及实现等3个方面展开,以及进行了属性集定义描述和相关配置软件的开发;采用该方法,可应用于施工期智慧工地平台、服役期智慧运维平台以及专项数据分析等场景;通过某桥梁模型的具体应用,结合桌面端和Web端的IFC模型解析器,验证了扩展物联模型在信息传递过程中的平台无关性。

Class Imbalanced Problem:Taxonomy,Open Challenges,Applications and State-of-the-Art Solutions

The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the power of data-driven machine learning(ML)and deep learning(DL)techniques.The data imbalance presents major hurdles for classification and prediction problems in machine learning,restricting data analytics and acquiring relevant insights in practically all real-world research domains.In visual learning,network information security,failure prediction,digital marketing,healthcare,and a variety of other domains,raw data suffers from a biased data distribution of one class over the other.This article aims to present a taxonomy of the approaches for handling imbalanced data problems and their comparative study on the classification metrics and their application areas.We have explored very recent trends of techniques employed for solutions to class imbalance problems in datasets and have also discussed their limitations.This article has also identified open challenges for further research in the direction of class data imbalance.

基于IFC拓展模型的邻近施工对既有地铁隧道变形影响研究

随着土木行业的信息化发展,BIM技术在土木工程中的应用不断拓展。为解决以往邻近施工过程中难以准确反映施工加卸载对既有建(构)筑物影响的问题,文章依托某邻近既有地铁隧道施工的建筑工程,首先在概述IFC模型多种拓展机制并对比其优缺点的基础上,对BIM模型进行IFC属性集工况信息拓展;然后,通过数值模拟方法,进行邻近施工加卸载荷载模拟,并据此建立IFC实体数据与加卸载施工对地铁隧道变形影响值的数学定量关系;最后,基于IFC模型中的几何数据信息及拓展属性信息,提出能够直观展现施工加卸载对既有地铁隧道变形影响的信息化方法,并对其计算出的影响值与实际施工过程中地铁隧道竖向变形值进行相关性分析。研究结果表明,IFC模型属性集拓展方法能够对工况信息进行有效补充;邻近施工加卸载荷载对既有地铁隧道变形的影响规律呈近似指数函数关系;所提方法算出的施工加卸载对既有地铁隧道变形影响值与地铁隧道变形实际监测值具有较高的相关性,能够准确反映施工加卸载对邻近地铁隧道变形的影响情况。

BLS-identification:A device fingerprint classification mechanism based on broad learning for Internet of Things

The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security risks.As a network-level security authentication method,device fingerprint based on machine learning has attracted considerable attention because it can detect vulnerable devices in complex and heterogeneous access phases.However,flexible and diversified IoT devices with limited resources increase dif-ficulty of the device fingerprint authentication method executed in IoT,because it needs to retrain the model network to deal with incremental features or types.To address this problem,a device fingerprinting mechanism based on a Broad Learning System(BLS)is proposed in this paper.The mechanism firstly characterizes IoT devices by traffic analysis based on the identifiable differences of the traffic data of IoT devices,and extracts feature parameters of the traffic packets.A hierarchical hybrid sampling method is designed at the preprocessing phase to improve the imbalanced data distribution and reconstruct the fingerprint dataset.The complexity of the dataset is reduced using Principal Component Analysis(PCA)and the device type is identified by training weights using BLS.The experimental results show that the proposed method can achieve state-of-the-art accuracy and spend less training time than other existing methods.

基于IFC标准的建筑工程造价管理方法

为改变目前工程造价管理方法存在实际造价与成本相差较大、缺乏对建筑信息技术的支持等一系列问题,提出基于IFC标准的建筑工程造价管理方法。该管理方法以计算赢得值为基础,构建工程造价曲线模型,判断项目的进度。导出并转化IFC文件,输出结果可检验工程造价信息是否准确。结果表明:与传统方法相比,基于IFC标准的建筑工程造价管理方法能够有效地减少项目的整体造价,提升工程的管理效益。

Extensive numerical simulations on competitive growth between the Edwards–Wilkinson and Kardar–Parisi–Zhang universality classes

Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and Kardar–Parisi–Zhang(KPZ) universality classes, respectively. The linear growth systems include the EW equation and the model of random deposition with surface relaxation(RDSR), the nonlinear growth systems involve the KPZ equation and typical discrete models including ballistic deposition(BD), etching, and restricted solid on solid(RSOS). The scaling exponents are obtained in both the(1 + 1)-and(2 + 1)-dimensional competitive growth with the nonlinear growth probability p and the linear proportion 1-p. Our results show that, when p changes from 0 to 1, there exist non-trivial crossover effects from EW to KPZ universality classes based on different competitive growth rules. Furthermore, the growth rate and the porosity are also estimated within various linear and nonlinear growths of cooperation and competition.

基于IFC的铁路信号工程信息模型的研究

本文研究了基于IFC标准的铁路信号工程信息模型构建,旨在通过标准化数据模型促进铁路BIM技术的应用。研究深入探讨了IFC体系架构,并据此设计了核心层与领域层模型,定义了详尽的属性集与枚举类型。所构建的模型实现了数据的标准化、可扩展性及互操作性,为铁路信号系统的全生命周期管理提供了有力支持,对推动铁路行业的信息化与智能化发展具有重要意义。

基于IFC标准的高架地铁车站三维建模及信息集成技术应用

文中围绕基于IFC标准的高架地铁车站三维建模及信息集成技术展开研究。阐述了该技术的重要性,其集成模型是信息交互载体和相关系统输入文件。介绍工程概况,以裕丰街站为例说明,重点研究了高架车站的IFC扩展,包括基本框架、标准扩展(实体和属性集扩展)以及基于IFC的高架车站结构体系(空间、物理和施工信息表达)。描述了高架车站信息集成模型构建过程,涵盖构件族库建立、IFC标准领域层实体定义以及集成模型拓展验证。通过验证表明拓展方式可行,解决了IFC标准在高架车站领域的相关问题。最后得出结论,提出一种BIM模型建立方法,满足设计施工要求,具有指导意义。

World Class Elite Breaststrokers Downward Kick EMG Muscle Activity of the Gluteus Maximus, Quadriceps Femoris, Hamstring, Gastrocnemius Medialis, Rectus Abdominal, and Erector Spinae

This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,quadriceps femoris(vastus medialis and rectus femoris),hamstring/long head of the biceps femoris,gastrocnemius medialis,rectus abdominal,and erector spinae when using the downward breaststroke kick technique.We find that when this sample of swimmers utilized the downward breaststroke kick,max speed and velocity per stroke increased,measured by 12,788 EMG samples,where the results are highly correlated to duration of the aerodynamic buoyant force in breaststroke kick technique.The increases in performance observed from measuring the world class elite swimmers is highly correlated to the duration of the kick aerodynamic buoyant force.Among this sample of elite swimmers,the longer a swimmer demonstrates a buoyant force breaststroke kick,the lower the time in a 100 breaststroke.

Simple and effective method for treating severe adult skeletal class II malocclusion: A case report

BACKGROUND Severe skeletal class II malocclusion is the indication for combined orthodontic and orthognathic treatment.CASE SUMMARY A woman with a chief complaint of a protruding chin and an inability to close her lips requested orthodontic camouflage.The treatment plan consisted of extracting the right upper third molar,right lower third molar,left lower second molar,and left upper third molar and moving the maxillary dentition distally using a convenient method involving microimplant nail anchors,push springs,long arm traction hooks,and elastic traction chains.After 52 months of treatment,her overbite and overjet were normal,and her facial profile was favorable.CONCLUSION This method can be used for distal movement of the maxillary dentition and to correct severe skeletal class II malocclusion in adults.

Research and Practice of Flipped Classroom Teaching Mode of Integrated Business English Course Under MOOC Environment

As an online course-teaching mode,Massive Open Online Course(MOOC)has drawn great attention from both teachers and students.It is necessary to give full play to the advantages of MOOC resources and to enhance teachers’consciousness of“identity remodeling”in the process of Integrated Business English flipping classroom teaching.Combining the advantages of MOOC and flipped classroom teaching during before-,during-,and after-class will greatly help promote the overall quality of business English teaching in universities.

Thin-Shell Wormholes Admitting Conformal Motions in Spacetimes of Embedding Class One

This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while the surface pressure is negative, resulting in , thereby signaling a violation of the null energy condition, a necessary condition for holding a wormhole open. For a Morris-Thorne wormhole, matter that violates the null energy condition is referred to as “exotic”. For the thin-shell wormholes in this paper, however, the violation has a physical explanation since it is a direct consequence of the embedding theory in conjunction with the assumption of conformal symmetry. These properties avoid the need to hypothesize the existence of the highly problematical exotic matter.

幼儿园自然探究活动中师幼互动的提升策略——基于CLASS评估调研分析

自然探究活动在培养幼儿实践能力与创造力方面具有显著优势,而活动中的师幼互动是保障活动质量的关键。使用CLASS评估系统,对广州市南沙区两所公办幼儿园教师在自然探究活动中的师幼互动情况展开实证调研的结果显示,教师在情感支持方面表现出积极态度,但在教育支持,尤其是促进幼儿概念发展和语言示范方面仍有待加强。其原因在于,教师科学素养较低,科学领域核心经验匮乏;教师组织管理能力存在短板,亟需深化有效教学策略;情感支持得分虚高,教师敏感性差异明显。基于此,需要加强专业培训,优化探究体验;提升师幼互动知识技能,补齐活动组织短板;优化情感支持策略,提升教师敏感性。