A new method in highway route design: joining circular arcs by a single C-Bézier curve with shape parameter   总被引：1，自引：1，他引：0  

Hua-hui Cai  Guo-jin Wang 《浙江大学学报(A卷英文版)》2009,10(4):562-569

We constructed a single C-Bezier curve with a shape parameter for G^2 joining two circular arcs. It was shown that an S-shaped transition curve, which is able to manage a broader scope about two circle radii than the Bezier curves, has no curvature extrema, while a C-shaped transition curve has a single curvature extremum. Regarding the two kinds of curves, specific algorithms were presented in detail, strict mathematical proofs were given, and the effectiveness of the method was shown by examples This method has the following three advantages： （1） the pattern is unified; （2） the parameter able to adjust the shape of the transition curve is available; （3） the transition curve is only a single segment, and the algorithm can be formulated as a low order equation to be solved for its positive root. These advantages make the method simple and easy to implement.  相似文献   

Studying transitions: Past,present, and future     

《Research Policy》2019,48(9):103788

The domain of transition studies has been drawing more and more scholarly attention and, as a result, its body of knowledge is rapidly growing. This raises new challenges as well as opportunities, not the least regarding the methodological and philosophical underpinnings of research in this domain. In this respect, transition research, as a relatively young field of inquiry, has been little concerned with methodological investigation and reflection. We propose a framework that enables this reflection: the so-called ‘transition research onion’. Subsequently, we utilize this framework to systematically assess 217 peer-reviewed papers in the field of transition studies, to distill key methodological patterns and trends of the field. The findings suggest that the methodology of transition studies, in terms of depth and diversity, is underdeveloped. These insights serve to guide future research on transition processes.  相似文献   

俄罗斯新闻教育观念的转变与困境     

赵永华 《国际新闻界》2009,(4)

本文考察了社会转型背景下俄罗斯新闻教育在思想观念上的新变化,综合分析了俄罗斯新闻教育所处困境。概括地讲,目前俄罗斯新闻教育思想呈现多元化、自由化、人文化、公民化特点;对国外新闻教育模式有选择地加以借鉴。新闻无学、新闻教育无用观点困扰着俄罗斯新闻教育,俄高校倡导与媒体合作的同时坚守大学之道。  相似文献   

Institutional change in a transitional economy: the reform of economics higher education in Mongolia     

Bernard Walters  David Hall  Frederick Nixson  Peter Stubbs 《International Journal of Educational Development》1999,19(6):639

This paper discusses the problems of implementing a European Union Technical Assistance to the Commonwealth of Independent States (of the former Soviet Union) (EU/TACIS) project to reform Mongolian Economics Higher Education with the ultimate objective of improving the process of economic policy making. It emphasises the importance of historical, economic and administrative context for the design and implementation of project activities. Project activities are reviewed and the problems of implementation discussed in terms of the aid relationship and the particular circumstances of transition economies. The paper concludes that, while the project's immediate objectives in terms of curriculum reform have been achieved, the sustainable change necessary to deliver the central, long-term objective remains elusive.  相似文献   

芳香醛,酮缩氨基硫脲过渡金属配合物合成方法探讨   总被引：2，自引：0，他引：2  

刘建宁  董彦杰 《宁夏师范学院学报》1999,20(3):3-5

介绍了芳香醛,酮过渡金属配合物,从一些芳香醛,酮缩氨基硫脲过渡金属配合物合成中溶剂、温度,反应介质等条件的选择,归纳了合成这类配合物的基本法则。  相似文献   

论伊莉莎·海伍德试验性的巧妙转变     

鲁芳 《海外英语》2015,(2)

该文旨在通过探讨十八世纪被遗忘的女性作家伊莉莎·海伍德的早期代表作Love in Maze和她的后期代表作The History of Miss Betsy Thoughtless,揭示她是如何在道德说教小说上升的英国十八世纪中期进行了试验性的巧妙转变,并且在迎合小说市场的同时传达了怎样的女性主义信息。  相似文献   

Best practice in conducting RCTs: Lessons learnt from an independent evaluation of the Response-to-Intervention programme     

《Studies in Educational Evaluation》2015

This paper presents the findings of the first independent UK evaluation of a large-scale randomised controlled trial of Response-to-Intervention, used as a catch-up literacy intervention. A total of 385 pupils in their final year of primary school (Year 6) were involved in the study (181 treatment and 204 control). These were identified as those at-risk of not achieving the threshold Level 4 in English at Key Stage 2. The pupils came from 49 schools across England. Twenty-seven schools were randomised to receive treatment immediately and 22 schools, which formed the control, were randomised to receive the intervention later. RTI was delivered in the summer term in preparation for pupil transfer to secondary school. The overall impact based on the standardised New Group Reading Test (NGRT) showed an ‘effect’ size of +0.19, and of +0.48 when considering only free school meal eligible pupils. However, these results must be viewed with considerable caution given the high attrition (over 25%) especially from the control group, and unclear identification of pupils eligible for the intervention. The fact that the evaluators did not have direct contact with schools when trying to identify eligible pupils, and that the developers wanted to use the pre-test to identify eligible pupils, led to this being a weak trial. The significance of the work therefore lies at least as much in the lessons learnt as in the headline figures. We learnt that ideally no more than two parties should be involved in communicating with schools, so that relevant instructions are passed quickly and acted upon promptly. This helps minimise the risk of misunderstanding and dropout post-allocation. Prior training on the technicalities of trials and research in general is necessary for both developers and any staff delivering the intervention so that all parties involved understand their commitment and the need to provide accurate and complete data. In future trials of RTI, it would be better for individual eligible pupils to be randomised rather than schools. RTI should ideally be given a whole year to allow the full cycle to be implemented, and it should be delivered daily for at least 30 minutes.  相似文献   

The impact of COVID-19 on teachers' transition practices for students with disabilities in Illinois,USA     

Rasha ElSaheli-Elhage 《Journal of Research in Special Educational Needs》2023,23(1):62-75

Transition services are central in preparing youth with disabilities for opportunities in postsecondary education, employment and independent living. The life skills education acquired in school may be the only resources they receive to help them with this transition. With COVID-19, educational systems were interrupted, including the access of students with disabilities to service provision and transition services. This study aimed to investigate the impact of COVID-19 on teachers' transition practices for students with disabilities in the State of Illinois, United States and to identify factors associated with the differences in teachers' practices across eight domains of transition. Results indicated statistical significant differences in transition practices before and during COVID-19 in all eight domains. Gender, Race, School Closings & Type of School did not show significant associations with any of the eight domains. Emotional Disability was found to have a significant association with all eight domains, whereas Intellectual Disability did not show significant association with any of the eight domains. Grade level and teachers' educational level showed significant associations with certain domains. Future investigations into how COVID-19 changed teachers' transition practices for students with disabilities and the long-term impact that these changes will have on students' post-secondary outcomes are needed.  相似文献