跟踪误差约束下的布菜克-李特曼模型

布莱克-李特曼模型（简称“B—L模型”）在资产资本定价模型的基础上,使用贝叶斯方法把投资者观点加入到隐含期望收益率中。文章对B—L模型做了深入的分析．并且把模型应用到单个股票中。在这里我们用跟踪误差约束下的优化方法,找到了优化模型最佳跟踪误差。然后参照此跟踪误差确定了B—L模型的跟踪误差的大小,从而也就给出了B—L模型其他参数的数值,这减少了参数设定的随意性,使得模型更具有操作性和统一性。     

基于Sobel算子预处理的变分水平集曲线演化目标跟踪方法

针对变分水平集在曲线演化目标跟踪方法中,直接计算得到的模值图较杂乱,利用Gaussian函数首先对图像进行平滑处理,然后利用中心差分计算梯度,并推导出二者的作用等价于Sobel算子与图像作运算.实例表明该算法使得曲线在演化过程中能够准定位,从而实现目标的正确跟踪.     

动态环境下的企业竞争对手跟踪与监测

竞争对手跟踪与监测是竞争情报系统的核心内容,没有连续、持续的竞争对手跟踪与监测,就不可能有可靠、高效的战略决策。本文剖析了动态环境中的竞争对手跟踪与监测的内涵,构造了由正向机制与反推机制结合而成的跟踪与监测基本模型及识别模式、分析模式和预测模式3个支持模型。     

混合Kalman滤波器与Chamshift人脸跟踪算法的研究

文章通过Kalman滤波器预测由Camshift算法检测到的人脸窗1：7在下一帧图像可能出现的位置,进行下一帧图像的人脸跟踪．其中,Kalman滤波器的使用克服了单纯使用Cam-shift跟踪在遮挡或者丢失跟踪物体的不足,可以大大提高人脸跟踪的正确率．     

宁波教育学院2008届毕业生就业状况跟踪调查

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。     

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

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.     

高频串联谐振逆变器频率跟踪控制电路的仿真与应用

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。     

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

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.     

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

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.     

制度措施多管齐下 持续提高本科生源质量

本科生源质量的高低直接影响人才培养的质量和高校的办学水平,关系到高校的社会声誉、学科建设和事业发展。本文通过西安理工大学材料成型及控制工程专业在吸引优秀生源报考、提高生源质量方面开展的具体实践,提出了完善招生工作机制、强化招生宣传、建设优质生源基地、加强学科与专业建设以及强化学生学习过程的指导、跟踪和评估等确保与提高生源质量的具体举措。