一种基于智能手机的疲劳驾驶报警系统     

王一格 《南阳师范学院学报》2013,12(3):47-50

针对汽车疲劳驾驶提醒装置价格高、安装复杂的问题,提出了一种疲劳报警的新方法———开发一种软件实现智能手机疲劳驾驶提醒功能;提出对PERCLOS、眨眼频率、眼睛闭合速度等四种疲劳判断方法进行加权求和的判断法,提高了疲劳判断的精度和灵敏度;成功制作了软件图标、窗体和报警逻辑.  相似文献   

侗族萨岁信仰的美学考察——以通道坪坦古村“萨岁安殿仪式”为例     

钮小静  王淑贞 《怀化学院学报》2013,(2):5-7

萨文化是以萨岁信仰为核心的侗族民间信仰文化。2012年7月,通道侗族自治县坪坦村的侗民举办了一场"萨岁安殿仪式"的祭萨活动。该仪式有"迎萨"、"绕寨"、"祭萨"、"安萨"、"娱萨"等程序,展示出该村"萨岁"信仰的古风古韵美、全程的活态美、隆重美、虔诚美和神秘美,萨坛环境的宁静美、朴实美和人文美。  相似文献   

宁波教育学院2008届毕业生就业状况跟踪调查     

朱寺宏 《宁波教育学院学报》2013,15(1):27-29

了解毕业生的就业状况是高校毕业生就业工作中不可或缺的环节。为动态掌握毕业生的工作情况,了解毕业生对学校人才培养方面的意见和建议,有效推进和强化我校教育教学改革,做好我校毕业生就业指导工作,我们对本校2008届部分毕业生进行了跟踪调查。  相似文献   

Is academic tracking related to gains in learning competence? Using propensity score matching and differential item change functioning analysis for better understanding of tracking implications     

《Learning and Instruction》2020

This study analyzes gains in cognitive components of learning competence with respect to cohorts based on ability tracking in a Czech longitudinal study. Propensity score matching is used to form parallelized samples of academic and non-academic track students and to eliminate the effect of selective school intake. We applied regression models on the total scores to test for the overall track effect. Furthermore, we analyze scores and gains on the subscores and check for differential item functioning in Grade 6 and in change to Grade 9. While after 3 years, no significant difference between the two tracks was apparent in the total learning competence score, we did, however, find significant differences in some subscores and in the functioning of some items. We argue that item-level analysis is important for deeper understanding of the tracking implications and may provide the basis for more precise evidence-based decisions regarding the tracking policy.  相似文献   

个体在剪纸文化内涵认知方面的偏差研究     

鲍小春  许鑫  孙亚薇 《图书情报工作》2017,61(2):32-40

[目的/意义] 以剪纸作品为载体,通过探究不同个体在剪纸文化内涵认知上存在的偏差,了解在传统文化传播过程中导致个人对传统文化内涵认知的差异化的因素,以期能在传统文化的内涵识别、精准传播方面获得有益启示。[方法/过程] 通过眼动实验、问卷调查获取样本数据,采用方差分析判定影响个体对剪纸文化内涵认知的潜在因素。[结果/结论] 研究发现,文化程度、学科背景、对剪纸文化的了解程度、家庭文化氛围等因素会影响个体对剪纸文化内涵的识别,而性别则不会影响。在此基础上,就如何进行传统文化精准化传播给出建议。  相似文献   

光源啁啾与色散补偿研究     

强世锦 《武汉职业技术学院学报》2008,7(1):68-70,74

在不考虑光纤中的非线性效应时,通过对高斯和超高斯脉冲光源啁啾的色散理论模型和传输测试分析,得到色散限制关系式,对于色散系数D沿光纤长度z变化的情况,只要光发射机与光接收机间光纤的累积色散∫Ddz小于关系式中所限定的数值,啁啾对脉冲波形的影响就可获得明显减弱,为此给出各种色散补偿方法。  相似文献   

高频串联谐振逆变器频率跟踪控制电路的仿真与应用     

郭红 《宁波职业技术学院学报》2008,12(5):22-26

为了解决高频逆变电源负载参数变化引起固有谐振频率变化,导致逆变器效率降低及开关器件应力增加的问题,提出了一种以集成高速锁相环74HC4046为核心的、应用于功率MOSFET为主开关器件的高频串联谐振逆变电源的无相差频率跟踪控制系统,对电源的输出频率进行实时控制,并用Pspiee进行了仿真分析。结果证明,该系统具有较好的应用前景和推广价值。  相似文献   

Teachers’ perspectives of lower secondary school students in streamed classes – A Western Australian case study     

Olivia Johnston  Helen Wildy 《Educational studies》2018,44(2):212-229

Streaming in secondary schools is not beneficial for improving student outcomes of education with vast amounts of educational research indicating that it does not improve academic results and increases inequity. Yet teachers often prefer working in streamed classes, and research shows that teachers mediate the effects of streaming on students. This study sought to add to the understanding of teachers’ role in student learning by investigating how teachers conceptualise the students in streamed classes. A qualitative case study approach was used, where 18 teachers were interviewed in-depth to create narrative examples, three of which are presented here. These narratives summarise the research findings that teachers saw students in high and low streams as having homogenous characteristics according to five dichotomous categories: approach to learning, attitude to learning, learning style, autonomy and background. Students in mixed-ability classes were viewed along these same continua, but as more heterogeneous groups. Furthermore, these views of students had direct implications for how teachers planned for learning and the expectations that they held of their students. The discussion links streaming research with teacher expectation research, suggesting that teachers of streamed classes in this secondary school hold specific whole-class ideas that affect student learning. The article concludes with recommendations for further inquiry that links these two important fields of educational research.  相似文献   

Digital redesign tracker for cascaded analog systems with state saturation and external loads     

Jason Sheng-Hong Tsai  Meng-Che Wu  Leang-San Shieh 《Journal of The Franklin Institute》2005,342(7):852-876

This paper presents a newly developed digital redesign control scheme with a weighted switching strategy and output-reference tracking, for a cascaded analog system with state saturation and external loads. The proposed method improves the generally poor transition response and output deviation caused by state-saturation constraint and external loads. It replaces an existing or theoretically well-designed analog controller with state saturation, by a digital controller with almost identical performance.  相似文献   

基于前沿监测技术探讨“大开发”对鸟类迁徙及其栖息地的影响   总被引：1，自引：0，他引：1  

曹垒  孟凡娟  赵青山 《中国科学院院刊》2021,36(4):436-447

迁徙鸟类与地球上不同生态系统、当地生物多样性和人类文化的时空关联,诠释了"地球生命共同体"的理念。《关于特别是作为水禽栖息地的国际重要湿地公约》用鸟类数量来确定国际重要湿地,将地球上受威胁最严重的湿地生态系统和水鸟这两者的保护紧密联系在一起。亚洲的湿地丧失和退化导致水鸟数量锐减,相关监测和保护已迫在眉睫。中国科学院联合10个国家的鸟类和生态环境相关研究机构,建立了亚洲最大且拥有自主知识产权的迁徙鸟类运动生态数据库,获得了亚洲大型鸟类迁徙策略和通道的基础数据。研究发现,亚洲20多个国家的大型迁徙水鸟均利用我国的湿地,其集中利用区域不超过国土面积的1.5%,主要分布在6条大河流域的湿地。进而,探讨了湿地面积、涨落区和水文过程与鸟类数量和行为的关联性。"大开发",尤其是对湿地和水资源的开发,导致了水鸟栖息地丧失和退化、水鸟数量锐减。从全球视角分析,保护迁徙鸟类及其栖息地是人类面临的共同挑战。近年来,我国已对典型湿地开启了成功保护,这也为全球生物多样性保护提供了宝贵的实践经验和信心。最后,文章还提出了关于我国牵头组织全球迁徙鸟类及其栖息地监测和保护的建议。  相似文献