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151.
With advanced prediction modes of intra prediction, intra coding of H.264/AVC offers significant coding gains compared with previous video coding standards. It uses an important tool called Lagrangian rate-distortion optimization (RDO) technique to decide the best coding mode for a block, but the computational burden is extremely high. In this paper, we proposed an improved fast intra prediction algorithm including block type selection and mode decision algorithm based on analysis of edge feature of a block. Our algorithm filters out unlikely block type and candidate modes to reduce the RDO calculations. Experimental results showed that the proposed algorithm can reduce the computation complexity of intra prediction from 52.90% to 56.31%, with 0.04 dB PSNR degradation and 2% increase of bit rate. 相似文献
152.
A clinical task-based interview can be seen as a situation where the interviewer–interviewee interaction on a task is regulated
by a system of explicit and implicit norms, values, and rules. This paper describes how documenting and mapping triadic interaction
among the interviewer, the interviewee, and the knowledge negotiated can be used to increase procedural replicability of the
interview and accuracy of drawn conclusions about the interviewee’s thinking process. Excerpts from interviews with 25 inservice
mathematics teachers working on a task to make up a problem whose solution requires division of two fractions are discussed.
The excerpts illustrate the relationship between methodological decisions taken by the interviewer during the interview and
the applicability of the interview output to the research questions. A divergent analysis of the interviews with these teachers,
which spanned over two years and were conducted by four interviewers, is used to offer a framework for analyzing data collected
in clinical task-based interviews. 相似文献
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1IntroductionBackground subtraction methods are extensively ex-ploited for moving object detection in videos in manyapplications ,such as traffic monitoring[1],human mo-tion capture[2]and video surveillance[3]. The centralidea behind such methods is to segment foreground ini mage sequences taken from a fixed camera by com-paring each newframe to a model of the scene back-ground . Therefore , correctly and efficiently modelingand updating the background model is one of the mostchallenging aspec… 相似文献
157.
Lyn D. English 《Educational Studies in Mathematics》2006,63(3):303-323
This paper examines 6th grade children's local conceptual development and mathematization processes as they worked a comprehensive
mathematical modeling problem (creating a consumer guide for deciding the best snack chip) over several class periods. The
children and their teachers were participating in a 3-year longitudinal teaching experiment in which sequences of mathematical
modeling problems were implemented from the 5th grade (10 years of age) though to the 7th grade. In contrast to traditional
problem solving, mathematical modeling requires children to generate and develop their own mathematical ideas and processes,
and to form systems of relationships that are generalizable and reusable. Reported here is a detailed analysis of the iterative
cycles of development of one group of children as they worked the problem, followed by a summary of the mathematization processes
displayed by all groups. Children's critical reflections on their models are also reported. The results show how children
can independently develop constructs and processes through meaningful problem solving. Children's development included creating
systems for operationally defining constructs; selecting, categorizing, and ranking factors; quantifying quantitative and
qualitative data; and transforming quantities. 相似文献
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Tolar TD Lederberg AR Gokhale S Tomasello M 《Journal of deaf studies and deaf education》2008,13(2):225-240
Early developmental psychologists viewed iconic representation as cognitively less complex than other forms of symbolic thought. It is therefore surprising that iconic signs are not acquired more easily than arbitrary signs by young language learners. One explanation is that children younger than 3 years have difficulty interpreting iconicity. The current study assessed hearing children's ability to interpret the meaning of iconic signs. Sixty-six 2.5- to 5-year-olds who had no previous exposure to signs were required to match iconic signs to pictures of referents. Whereas few of the 2.5-year-olds recognized the meaning of the iconic signs consistently, more than half of the 3.0-year-olds and most of 3.5-year-olds performed above chance. Thus, the ability to recognize the meaning of iconic signs gradually develops during the preschool years. Implications of these findings for sign language development, receptive signed vocabulary tests, and the development of the ability to interpret iconic symbols are discussed. 相似文献