Joint rate control and scheduling for wireless uplink video streaming     

KATSAGGELOS Aggelos K. 《浙江大学学报(A卷英文版)》2006,7(5):801-810

INTRODUCTION Video streaming is becoming one of the major driving forces of next generation wireless networks. For the currently deployed cellular networks, the practical data rates are not enough to support full rate, high quality video applications. As a result, many research efforts have been devoted to adapting video content to reconcile the conflict between the high demand of video quality and the limited wireless communication resources among users. A large body of literature utiliz…  相似文献   

舞动的心     

Bettie B.Youngs  朱俊 《英语辅导》2007,(2)

“鲍勃!鲍勃!”我身旁的女人大声命令着,“告诉她你去年为什么不愿跟那个女人结婚!”桌子对面的鲍勃顺从地粗着嗓子回答：“哦,她呀!那真是糟透了!她对我说,要是想跟她结婚的话,我就再也不能去跳舞了!我就告诉她,‘噢,我想我做不到。’”  相似文献   

北太平洋巨型章鱼     

段玉佩  N.Tordjman  D.Florentz  M.Beurton 《少年科学》2011,(4):8-15

北太平洋巨型章鱼是170余种巨型章鱼中的一种。人们曾经误把它们看成为海怪,实际上,它们性格平和,并不像古老传说描述的那样会攻击船只。  相似文献   

The etiology of mathematical self-evaluation and mathematics achievement: understanding the relationship using a cross-lagged twin study from age 9 to 12     

Luo YL  Kovas Y  Haworth CM  Plomin R 《Learning and individual differences》2011,21(6):710-718

The genetic and environmental origins of individual differences in mathematical self-evaluation over time and its association with later mathematics achievement were investigated in a UK sample of 2138 twin pairs at ages 9 and 12. Self-evaluation indexed how good children think they are at mathematical activities and how much they like those activities. Mathematics achievement was assessed by teachers based on UK National Curriculum standards. At both ages self-evaluation was approximately 40% heritable, with the rest of the variance explained by non-shared environment. The results also suggested moderate reciprocal associations between self-evaluation and mathematics achievement across time, with earlier self-evaluation predicting later performance and earlier performance predicting later self-evaluation. These cross-lagged relationships were genetically rather than environmentally mediated.  相似文献   

The comprehension and production of Wh-questions in deaf and hard-of-hearing children     

Friedmann N  Szterman R 《Journal of deaf studies and deaf education》2011,16(2):212-235

Hearing loss during the critical period for language acquisition restricts spoken language input. This input limitation, in turn, may hamper syntactic development. This study examined the comprehension, production, and repetition of Wh-questions in deaf or hard-of-hearing (DHH) children. The participants were 11 orally trained Hebrew-speaking children aged 9.1-12.4 with moderate-to-profound hearing loss from birth, who consistently used hearing aids or cochlear implants and who had difficulties understanding relative clauses. Experiment 1 tested the comprehension of Wh-questions using a picture selection task, comparing subject with object questions and who- with which-questions; Experiment 2 tested the production of subject and object who-questions using an elicitation task; and Experiment 3 tested the repetition of Wh-questions and other structures derived by Wh-movement. All the DHH participants showed difficulty in the comprehension, production, and repetition of object questions, and their performance was significantly below that of hearing children. In contrast, they repeated embedded sentences without movement well, indicating that their deficit is in syntactic movement rather than embedding or the CP node in the syntactic tree. The results provide additional evidence that DHH children have difficulties with Wh-movement and emphasize that Wh-questions, which are crucial for communication, can be severely impaired in these children.  相似文献   

Stability in Mother-Child Interactions from Infancy through Adolescence     

Else-Quest NM  Clark R  Owen MT 《Parenting, science and practice》2011,11(4):280-287

OBJECTIVE: The current study examines homotypic stability in mother-child interactions, applying similar rating scales of mother-child interactions at 1 and 4.5 years, and heterotypic stability from 1 to 13 years and 4.5 to 13 years, using conceptually similar but not identical rating scales at age 13. DESIGN: We coded videotaped mother-child interactions in 202 families when children were 1, 4.5, and 13 years of age during age-appropriate and developmentally salient structured tasks for relationship quality. RESULTS: Multiple regression analyses controlled for the effects of child birth order and gender as well as maternal age and education. Maternal and dyadic, but not child, mother-child interaction qualities at 1 year significantly predicted similar or equivalent constructs at 4.5 and 13 years. Heterotypic stability from 1 to 13 years was partially or fully mediated by the same constructs at 4.5 years. CONCLUSIONS: Maternal behaviors showed a pattern of homotypic and heterotypic stability, whereas dyadic behaviors were somewhat less stable. Child behaviors showed evidence of both homotypic and heterotypic instability.  相似文献   

以90后视角写青春之作     

周.com 《中学生电脑》2011,(1)

我经常收到一些读者投稿,作文前面往往附着自我简介之类的资料,这些文字往往很有灵气,就是家常话也给人一种很亲切的感觉。比如,有个同学爆料她的家庭,说爸爸生意失败,一家人过得很苦,后来爸爸振作精神去跑运输,又出了车祸。妹妹不太听话,吃  相似文献   

11大周星驰头号接班人 揪出来     

八卦王&A. 《音乐世界》2002,(3)

周星驰了不得,一个人就能把千千万万男女老少逗得前仰后合稀里哗啦。不过,浩瀚搞笑天地,老是靠一人撑着顶着扛着玩着也实在难为他。偏偏他又喜欢孤身作战,老没下决心培养接班人,将周氏搞笑风采有计划有方向地传播延续下去。我等看在眼里,急在心里,特地为星爷苦心搜罗11位头号接班人,请无厘头掌门人尽早留心考察这些人选,争取在明年此时师徒并肩搞笑,星光DOUBLE灿烂!  相似文献   

Reporting child abuse: pediatricians' experiences with the child protection system     

Vulliamy AP  Sullivan R 《Child abuse & neglect》2000,24(11):1461-1470

OBJECTIVE: To explore pediatricians' reluctance to adhere to a legal mandate to report suspected child abuse and to compare their perspectives with those described in other jurisdictions in studies informed by different theories and employing diverse methodologies. METHOD: An anonymous survey questionnaire was distributed to all pediatricians with admitting privileges to B.C. Children's Hospital which has a specialized Child Protection Services Unit. Physicians were asked about their own prior reporting experience and the influence of that experience upon future reporting decisions. They were also asked why they think other physicians might be reluctant to report (N = 26). RESULTS: While respondents were generally positive about their experience in filing a report to Child Protective Services, they were less positive about the dearth of feedback they received and they were undecided as to whether there was a positive outcome to their report. Their perceptions of the reasons colleagues might fail to report emphasized dissatisfaction with CPS, concern with loss of relationship with the child's parents, and a desire to avoid court proceedings. CONCLUSIONS: Physicians' noncompliance or at least dissatisfaction with their child abuse reporting mandate is an international problem that can not be addressed by institutional protocols alone. Confusions about the limitations on confidentiality and information sharing might be better addressed through more shared training and opportunities for collaboration than by legal mandates and institutional protocols alone. Organizational theory and exchange theory might inform future research about the conditions under which collaboration is enhanced in the service of protecting children.  相似文献   

政治基本原理、人类发展理论与教育实践     

R·默里·托马斯  彭钢 《教育理论与实践》1988,(6)

要理解一个社会教育实践的发展,必须通过分析政治基本原理、人类发展理论和教育进程是如何相互作用的。“政治基本原理”是一种提出并证明某种政治体制合理性的观点。“人类发展理论”这一短语意指关于人们怎样扩展他的生活广度的一系列信念。每一种政治体制都建立在一种人类发展理论基础之上。我们把“教育实践”这个概念看作:在某一社会中,按照一种需要的形式,为塑造人的发展而有意识地采取的方法。此外,还须认识四种类型的理论:描述性的、潜在性的、或然性的和指令性的。描述性的理论试图阐明关于人类发展过程的经验主义观念。这种理论回答这样的问题:为什么人们采取了他们所希望的方式发展?相反,潜在  相似文献