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针对某光电对抗平台跟踪精度高、跟踪平稳连续的要求,提出了基于PI-P调节器的复合控制技术,具有结构简单、抗负载扰动能力强、控制平稳等特点,保证了系统的高精度跟踪;通过先对视频跟踪器数据进行合理性检验,然后与外部引导数据进行数据融合的方法,剔除干扰,提高对机动目标位置预测的可信度和准确度,保证目标跟踪的连续性和平稳性。实验结果表明,该方法满足系统高精度、平稳连续跟踪的要求,在保精度角速度20(°)/s,保精度角加速精度25(°)/s2时跟踪最大误差小于2′,该系统具有广泛的适用性。 相似文献
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针对民机增升构型失速特性的数值模拟,我们基于贪婪负载平衡算法的剖分工具对多块结构网格进行区域分割,在某新型超级计算机系统上完成求解软件的移植、优化和测试,采用 2 亿量级的计算网格开展大规模并行计算研究,测试完成了万核级负载平衡的网格区域分割,实现了增升构型失速特性的 4 096 核数并行计算,并行效率达到 50% 以上,提高了工程应用中对复杂流动现象的数值模拟能力。数值模拟结果加深了对增升构型失速流动机理的理解,可以为增升装置设计优化提供有意义的参考依据。 相似文献
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数字闭环光纤电流传感器暂态特性主要包含频率响应与阶跃响应,对于电力系统的继电保护控制、故障录波等应用领域至关重要。在工程应用中,传统的测试方法由于其测试系统复杂、测试电流信号小等问题,不利于评估光纤电流传感器的暂态特性。利用数字闭环光纤电流传感器的闭环控制机理,提出一种在数字闭环光纤电流传感器反馈回路中添加相位调制激励的方法。首先,分析数字闭环光纤电流传感器的相位调制原理,通过建立数学模型验证相位调制激励的等效性;其次,根据数字闭环光纤电流传感器闭环控制算法,提出频率响应与阶跃响应的调制激励产生方法;最后,利用现有数字闭环光纤电流传感器产品平台完成频率响应与阶跃响应的仿真与测试。结果表明:采用相位调制激励的仿真数据与试验数据最大误差为0.12%,该调制激励方法不需要搭建复杂的测试系统,在现有硬件平台中即可实现不同电流信号的仿真测试。 相似文献
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针对手工编制生产配套报表效率低、差错多的问题,分析企业现行产品图样设计规范和生产报表编制规则;充分利用现有CAD软件的报表模块和程序接口,经过二次开发实现用CAD软件自动生成汇总生产配套报表。 相似文献
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Research in the area of educational technology has argued that the technological pedagogical content knowledge of faculty is crucial to addressing the challenge of teaching in higher education in the digital age, which is characterized by the common use of instructional technology in college classrooms and the ubiquitous presence of computing on college campuses. We developed and validated an instrument for assessing students' perceptions of faculty knowledge (SPFK) in technology-supported classroom environments. A total of 50 items in 4 constructs with 9 items in subject matter knowledge (SMK), 11 items in technological knowledge (TK), 6 items in knowledge of students' understanding (KSU), and 24 items in technological pedagogical content knowledge (TPACK) were developed for the instrument. The construct validity of this instrument was examined through confirmatory factor analysis. After checking the construct structure of the instrument, the multidimensional version of the rating scale model (MRSM) was used to analyze item response data. Results showed that after the elimination of item 17, the 49-item instrument for assessing college students' perceptions of faculty knowledge was validated in the current study. The reliability for each subscale of this instrument was found to be satisfactory when analyzing data with the MRSM model. Discussion of results and recommendations for future research are also provided. 相似文献
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《Computers & Education》2002,39(3):299-312
Computer-based assessment (CBA) is yet to have a significant impact on high-stakes educational assessment, but the equivalence between CBA and paper-and-pencil (P&P) test scores will become a central concern in education as CBA increases. It is argued that as CBA and P&P tests provide test takers with qualitatively different experiences, the impact of individual differences on the testing experience, and so statistical equivalence of scores, needs to be considered. As studies of score equivalence have largely ignored individual differences such as computer experience, computer anxiety and computer attitudes, the purpose of this paper is to highlight the potential effects of these. It is concluded that each of these areas is of significance to the study of equivalence and that the often inconsistent findings result from the rapid changes in exposure to technology. 相似文献