《中国国家地理》:走在别人的影子里

别人的故事1888年1月,美国首都有一个非营利性的科学及教育机构成立,名字叫做国家地理学会(NationalGeographic Society),它的目的是为了增进及普及地理知识。同年10月,第一期的《国家地理杂志》(简称《NG》出版。我自从在中学时偶然在图书馆看过这本杂志后,就深深地爱上了它,虽然不明白它的文字,但是,它的照片和图画真是无比精彩,绝对叫人难忘。有人称它为全世界图     

Integration Factors Related to the Academic Success and Intent to Persist of College Students with Learning Disabilities

Despite increased enrollment, outcomes such as grade point average (GPA), persistence, and graduation rates for college students with learning disabilities (LD) continue to lag behind those of their nondisabled peers. Reasons for the differences vary but may include academic and social integration, factors identified as important to the success of college students in general. This research investigated the relative influence of background characteristics, precollege achievement, and college integration variables on the academic success and intent to persist of college freshmen and sophomores with LD. While academic and social integration were not unique predictors of college GPA, both integration variables were unique predictors of intent to persist. The findings suggest that beyond high school achievement and background characteristics, college experiences as captured by academic and social integration are promising constructs to help explain the persistence of college students with LD. Implications for future research and practices for high school and college personnel are discussed.     

三维影相的新算法——修正的直接线性变换

通过引入摄影机镜头的内、外方位元素的约束条件,导出了一种修正的DLT(MDLT)方法。该方法用于影片和录相的实测,得到一些有意义的结果。当测量的标定控制点点数较少(6～8个),且这些点的位置在空间和成像面分布不均匀时,用MDLT计算的结果比DLT的结果要好,误差可降低80％以上。     

Assessing the Utility of Item Response Models: Computerized Adaptive Testing

How has Item Response Theory helped solve problems in the development and use of computer-adaptive tests? Do we need to balance item content with computer-adaptive tests? Could we use IRT to evaluate unusual responses to computer-delivered tests?