Analysis of the integrated test and evaluation methods of tidal current energy generating devices in the offshore testing site

Actual sea condition testing and inspection and evaluation method research are carried out for tidal energy devices to provide scientific and effective technical support for the ocean high-tech achievement transformation and marine renewable energy development. By analyzing three core indicators, including the power output characteristics of the tidal current device, the generating capacity, energy conversion efficiency, proposed the test contents and evaluation methods of indicators are proposed in this paper; and based on the research of wind farms, power quality testing and assessment methods of offshore tidal energy device are proposed; given the security access to the test contents of tidal current energy device, tidal current energy device running conditions in the testing ground are comprehensively assessed.

Parameters Sensitivity Characteristics of Highly Integrated Valve-Controlled Cylinder Force Control System

Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.

Test Case Prioritization in Unit and Integration Testing:A Shuffled-Frog-Leaping Approach

Both unit and integration testing are incredibly crucial for almost any software application because each of them operates a distinct process to examine the product.Due to resource constraints,when software is subjected to modifications,the drastic increase in the count of test cases forces the testers to opt for a test optimization strategy.One such strategy is test case prioritization(TCP).Existing works have propounded various methodologies that re-order the system-level test cases intending to boost either the fault detection capabilities or the coverage efficacy at the earliest.Nonetheless,singularity in objective functions and the lack of dissimilitude among the re-ordered test sequences have degraded the cogency of their approaches.Considering such gaps and scenarios when the meteoric and continuous updations in the software make the intensive unit and integration testing process more fragile,this study has introduced a memetics-inspired methodology for TCP.The proposed structure is first embedded with diverse parameters,and then traditional steps of the shuffled-frog-leaping approach(SFLA)are followed to prioritize the test cases at unit and integration levels.On 5 standard test functions,a comparative analysis is conducted between the established algorithms and the proposed approach,where the latter enhances the coverage rate and fault detection of re-ordered test sets.Investigation results related to the mean average percentage of fault detection(APFD)confirmed that the proposed approach exceeds the memetic,basic multi-walk,PSO,and optimized multi-walk by 21.7%,13.99%,12.24%,and 11.51%,respectively.

Strategy and Methodology of Integration Testing for GUI Software

In this paper, by means of effective testing practices, main strategies of integration testing for GUI software, including differentiating strategy for distinguished system, strategy of personnel organization, incremental testing strategy based on baseline version, testing strategy of circulating loop through the whole life, and the strategy of test suite construction, were briefly investigated. Moreover, for the code analysis, the FTA (Fault Tree analysis) is proposed to deal with the software change in regression testing. For test suite constructing, the constructing methods for baseline version and the incremental change are deeply discussed, in which main points focus on the testing strategy based on “Sheet/Form”, the “Grey-box approach” for integration testing process, and the application of the improved STD (State Transform Diagram) in state testing. At the same time, the suite construction of integration testing for two types, including small scale program and large scale software, is analyzed and discussed in detail. For testing execution, the specific method based on “Cross-testing” is investigated. Concurrently, by a lot of examples, all results of testing activity indicate that these strategies and methods are useful and fitted to integration testing for GUI software.

基于临床思维培养的中药学课程教学实践

中药学课程对高校培养中医学专业人才中医临床思维具有重要意义。教师需不断提升教学能力和专业素养,重新认识中药学课程地位,积极采用线上线下相融合的混合式教学模式。教材内容整合重排,融入中医经典与名家经验及医案,传承中医药认知思维及文化,补充教材内容之不足,并积极开展第二课堂,提高应用题型测试考核比例,以优化拓展教学内容,增强教学内容的临床实用性、引导性,提升学生的思想、思考、思辨能力,提高中医思维的高度、宽度及深度。

路基路面试验装置伺服加载系统设计及分析

【目标】针对现有路基路面力学性能检测在加载时存在加载荷载单一、加载精度不足等问题,提出了采用电液伺服加载方法的加载系统,应用于路基路面试验装置。【方法】首先,根据实际工程情况,对电液伺服加载系统各组成进行设计,根据系统工作机理及系统元件工作特性建立系统传递函数数学模型。其次,采用比例积分微分控制作为系统控制方法,并对系统数学模型进行仿真。然后,搭建路基路面试验装置电液伺服加载系统,并进行动、静态加载试验。最后,为提高系统控制精度,提出自抗扰控制应用于加载系统,通过把系统3阶及以上阶数视为总扰动一部分,从而对系统进行了降阶处理,采用扩张状态观测器对系统状态及总扰动进行观测,并进行了仿真验证。【数据】所设计电液伺服加载系统满足动态加载最大频率15 Hz的加载要求,在动、静态加载时,输出最大误差和平均绝对误差均小于0.5 kN,且不存在超调现象,但输出最大误差接近0.5 kN情况较多;【结果】在采用自抗扰控制后,加载系统在准确性上有较大提升,系统控制性能得到优化。【应用】采用电液伺服加载系统作为路基路面力学性能检测荷载发生装置,可更全面、更精准地模拟路基路面实际受力状况,有利于路基路面力学性能检测的进一步研究。

智能终端整机性能测试领域校企合作人才培养模式研究

随着5G通信技术的广泛应用,智能终端产业蓬勃发展,智能终端整机性能测试领域的人才需求增加。目前,智能终端整机性能测试领域人才培养模式相对滞后,亟需创新性探索和实践。为适应整机性能测试行业对高素质应用型人才的需求,应积极推动校企合作育人,具体方式为,校企共同制定培养目标和改革教学模式;共建师资团队和教学实践平台;产学研深度融合并促进成果转化。智能终端整机性能测试技术人才培养只有实现高校与产业紧密衔接,才能达到理想的人才培养目标。

面向MMC应用的大功率IGCT器件加速老化试验拓扑研究

集成门极换流晶闸管(integrated gate commutated thyristor, IGCT)具有阻断电压高、通流能力强等特点,在柔性直流输电等领域具有广阔的应用潜力,但其在高电压、大通流应力下的可靠性问题,成为限制应用的潜在因素,如何针对不同工况开展加速老化等效测试成为开展可靠性研究的关键瓶颈。文中以模块化多电平换流器(modular multilevel converter,MMC)工况为代表,针对IGCT器件可靠性等效测试难题开展研究。首先分析MMC工况下IGCT器件的暂态电气应力和长期电热应力,分别采用TCAD仿真软件与平均值等效计算模型定量获得IGCT器件在实际工况下的应力大小;其次,基于应力分析结果,提出一种三半桥式两级电流应力加速老化试验拓扑,设计并搭建2 500 V/4 000 A/150 Hz参数的IGCT加速老化试验平台;最后,开展约100 h高压、大电流老化运行试验,验证平台具备长时运行的能力,且等效测试应力达到设计要求。所提出的等效拓扑及其构建方法,不仅解决了MMC工况下IGCT器件的加速老化测试问题,对其他交直流变换工况、其他类型功率半导体亦有很好的参考价值。

后危机时代国际物流与国际贸易的关系研究——基于浙江省数据的Granger与Cointegration检验

从国际贸易与国际物流的关系角度出发,充分考虑后危机时代的经济特点,运用格兰杰因果检验和协整分析的方法,通过对后危机时期浙江省各个月份国际物流以及国际贸易的相关指标,分析二者之间存在的因果关系,根据实证得出的结论,结合浙江省的具体发展情况,因地制宜地提出相应建议。

“结构检验与试验”课程产教融合改革研究与探索

“结构检验与试验”是土木工程专业学生的必修专业课,课程通过理论教学与实验操作,培养学生的实践和创新能力。该文阐述了教学团队对课程内容与特点的思考,针对现有问题,教学团队从多方面分层次进行了教学改革探索,并基于产教融合教学模式提出了“理论—实践”内外双循环的改革思路。将企业元素深度融入授课体系,能够有效突破课程在时间与空间方面所面临的局限,打破学生与行业之间的隔阂,加强高校与企业之间的联动。改革后的课程将更有利于培养满足行业和社会发展需求的应用型人才,提高学生知识运用和再创造能力。

混凝土边框率对结构保温一体化墙板热工性能影响的试验研究

为了响应国家“十四五”规划大力发展装配式建筑,提升新建建筑节能水平的号召,助力国家“双碳”目标的实现,研发了一种预制结构保温一体化复合夹心墙板.墙板四周设置实心混凝土边框作为连接件,以实现墙板的全干式连接.边框的存在形成显著的热桥,这在很大程度上决定了墙板的热工性能.确定边框率对墙板热工性能的定量影响,对于墙板的构造设计优化和实际工程应用具有重要指导性作用.因此,本文设计了6组具有不同边框率的墙板试件,采用标定热箱法对试件进行测试,定量地分析边框率对预制墙板热工性能的影响规律.试验结果表明:混凝土边框的存在,不仅延长了墙板热传递达到稳态的时间,还极大降低了墙板的热工性能.边框率为19.94%、30.85%、40.95%、50.26%和61.43%时,墙板热阻值分别降低了79.26%、84.28%、87.48%、89.36%和91.10%.为满足现行建筑节能要求,在实际工程应用中要将墙板边框率控制在20%以内.通过对现有墙板热阻值计算方法和试验结果的对比分析,推荐采用区域法作为带边框墙板热阻值计算方法.

纵梁铝合金压铸件浇注排溢系统设计

研究了浇注排溢系统对纵梁铝合金压铸结构件压铸模拟结果的影响。根据仿真模拟结果,研究了压铸件结构设计对压铸工艺结果的影响,对纵梁压铸件设计、性能检测等关键技术开展理论和实验研究,进一步为新能源汽车一体化车身结构件优化设计提供参考。

基于“岗课赛证”融通的活页式教材开发实践——以软件测试技术课程为例

软件测试课程强调实践,旨在培养综合技能。本文探索活页式教材建设,紧密对接岗位需求,整合课程内容,融入技能大赛精髓,并参照职业证书标准,实现“岗课赛证”深度融合。通过科学教学设计,助力学生系统构建软件测试知识体系。

飞机液压/起落架系统集成测试平台设计

为提高飞机地面功能试验测试效率与测试质量,采用设备控制层、数据管控层、数据服务层和平台应用层四层架构,基于Unity3D软件设计开发了飞机液压/起落架系统集成测试平台,该平台可实现设备管理、试验测试、数据管理等。同时搭建平台测试环境,对智能功能测试终端的有效性与准确性进行了验证。试验结果表明,该平台能快速实现地面功能试验测试,提高测试效率与测试质量,有效提高了飞机地面功能试验测试的智能化与自动化水平。

LDRA Testbed在动车EBCU软件测试中的应用与研究

动车制动控制系统是高铁安全运行的重要保障。随着动车系统的复杂性和自动化程度的提高,对制动控制系统的软件测试也提出了更高的要求。文章通过将LDRA Testbed软件自动化测试工具应用于动车EBCU软件,详细介绍了静态分析、单元测试及集成测试的方法和步骤,并结合实际测试结果分析其有效性和重要性。通过全面的测试手段,不仅提高了EBCU软件的可靠性和安全性,还为动车制动控制系统的维护和优化提供了科学依据。

一种防护时间测试装置的设计

设计了一种防护时间测试装置,主要用于自吸过滤式防毒面具防护时间的测试。该系统以PLC为控制核心,配置有配气系统、控温控湿系统和检测系统,能够按照GB 2890—2022要求自动完成防护时间测试并记录测试数据。控制系统采用增量式PID算法完成气体参数的闭环控制。测试结果表明:该装置能够稳定控制测试气体浓度,测试数据准确可靠,满足防护时间测试的要求。

混凝土灌注桩桩身完整性的验证检测实例分析

通过桩身完整性检测可发现混凝土灌注桩某些可能影响承载力或耐久性的缺陷,灌注桩的桩身可能的缺陷类别和出现形式较多,加之检测方法的特点和适用性的不同,往往会出现采用一种方法不能全面评判的情况。结合工程实例,介绍了如何综合运用多种检测方法合理判定灌注桩的桩身完整性,实践证明,工程中选用检测方法应该灵活搭配、互相验证,避免误判或漏判的发生,使灌注桩的完整性检测结果更加准确可靠。

Pulsed Eddy Current Non-destructive Testing and Evaluation:A Review

Pulsed eddy current （PEC） non-destructive test- ing and evaluation （NDT＆E） has been around for some time and it is still attracting extensive attention from researchers around the globe, which can be witnessed through the reports reviewed in this paper. Thanks to its richness of spectral components, various applications of this technique have been proposed and reported in the lit- erature covering both structural integrity inspection and material characterization in various industrial sectors. To support its development and for better understanding of the phenomena around the transient induced eddy currents, attempts for its modelling both analytically and numeri- cally have been made by researchers around the world. This review is an attempt to capture the state-of-the-art development and applications of PEC, especially in the last 15 years and it is not intended to be exhaustive. Future challenges and opportunities for PEC NDT＆E are also presented.

Practical integrated navigation fault detection algorithm based on sequential hypothesis testing

In detecting system fault algorithms,the false alarm rate and undectect rate generated by residual Chi-square test can affect the stability of filters.The paper proposes a fault detection algorithm based on sequential residual Chi-square test and applies to fault detection of an integrated navigation system.The simulation result shows that the algorithm can accurately detect the fault information of global positioning system（GPS）,eliminate the influence of false alarm and missed detection on filter,and enhance fault tolerance of integrated navigation systems.

科教融合创新型实验:CoZn复合催化剂催化5-羟甲基糠醛氢解性能测试

为了将前沿的新材料、新技术和新方法融入到本科基础实验教学中,拓宽化学专业高年级学生的学科视野,通过科教融合,我们设计了一个创新综合实验——CoZn复合催化剂催化5-羟甲基糠醛氢解性能研究。实验内容包括Co/ZnO催化剂的制备、形貌及结构表征、氢解性能测试等。该实验将无机化学、分析化学和物理化学等学科知识相结合,具有创新性、综合性和可操作性等特点,能够有效提升本科学生的科学素养和创新实践能力。