Header error control schemes for coping with upstream channel noise in the HFC network

The Hybrid Fiber-Coax (HFC) network is being paid close attention to in recent years as a bi-directional broadband access network. To achieve seamless connection with the backbone network, and Asynchronous Transfer Mode (ATM) Network Network Interface (NNI) cell format is used as the basic transmission packet unit in the HFC system. As the transmission condition of the HFC system’s upstream channel is bad, two improved header error control (HEC) schemes, i. e. the improved HEC and the cell interleaving technique, are employed to guarantee the packet integrity. Theoretical analysis of the results showed that the improved HEC and the cell interleaving technique are applicable to isolated random errors and burst errors, respectively.     

2004年荆州市初中数学竞赛(初三)

一、选择题(每小题5分,共30分)1.若n满足(n-2004)2 (2005-n)2=1,则(2005-n)(n-2004)等于().(A)-1(B)0(C)12(D)1图12.如图1,已知∠CGE=120°.则∠A ∠B ∠C ∠D ∠E ∠F=().(A)150°(B)210°(C)240°(D)270°3.设x、y、z均为正实数,且满足zx y相似文献   

浅谈英语专业二外法语教学

本文介绍了法语的特点及英语专业选择二外法语的原因,针对教学中面临的问题,提出了自己的观点及解决的方法,着重阐述了英法比较的方法。     

试论马克思主义历史决定论的双重属性

马克思主义历史决定论既强调社会历史发展的决定性，又肯定其主体选择性。本在分别阐述其历史决定性和主体选择性的基础上，把二统一在一起，称之为马克思主义历史决定论的双重属性。     

圆周上的范德瓦尔登数

The big upper bound of typical van der Waerden number was investigated through calculating the van der Waerden number on a circle. And the van der Waerden number Wh (3,3) = 9, Wh (3,3,3)≥25 on a circle was calculated by computer.     

论成人教育发展与国民素质培养

人的良好素质是国民个体成功的基石，国民素质的普遍提高就可以为国家的兴旺发达提供坚实的基础。成人教育不但能帮助成年人补充人生前期教育的缺陷和不足，而且可以帮助劳动者追随社会的发展变化和科学技术进步不断获得新思想、新知识、新技术和新方法，以提高自身的素质和能力。因此，大力发展成人教育，不断拓展它的功能，对于有效开发人力资本，提高我国的国民经济发展水平，推动社会全面进步都有重要的作用和价值。     

Correlates of Work-Life Balance for Faculty Across Racial/Ethnic Groups

Very few studies have examined issues of work-life balance among faculty of different racial/ethnic backgrounds. Utilizing data from Harvard University’s Collaborative on Academic Careers in Higher Education project, this study examined predictors of work-life balance for 2953 faculty members from 69 institutions. The final sample consisted of 1059 (36%) Asian American faculty, 512 (17%) African American faculty, 359 (12%) Latina/o faculty, and 1023 (35%) White/Caucasian faculty. There were 1184 (40%) women faculty and 1769 (60%) men faculty. The predictors of worklife balance included faculty characteristics, departmental/institutional characteristics and support, and faculty satisfaction with work. While African American women faculty reported less work-life balance than African American men, the reverse was true for Latina/o faculty. In addition, White faculty who were single with no children were significantly less likely to report having work-life balance than their married counterparts with children. Faculty rank was a significant positive predictor of work-life balance for all faculty. Notably, the findings highlight the importance of department and institutional support for making personal/family obligations and an academic career compatible. Institutional support for making personal/family obligations and an academic career compatible was consistently the strongest positive predictor of perceived work-life balance for all faculty. In addition, satisfaction with time spent on research had positive associations with work-life balance for all faculty, highlighting how faculty from all racial/ethnic backgrounds value being able to spend enough time on their own research.     

On mathematical understanding: perspectives of experienced Chinese mathematics teachers

Researchers have long debated the meaning of mathematical understanding and ways to achieve mathematical understanding. This study investigated experienced Chinese mathematics teachers’ views about mathematical understanding. It was found that these mathematics teachers embrace the view that understanding is a web of connections, which is a result of continuous connection making. However, in contrast to the popular view which separates understanding into conceptual and procedural, Chinese teachers prefer to view understanding in terms of concepts and procedures. They place more stress on the process of concept development, which is viewed as a source of students’ failures in transfer. To achieve mathematical understanding, the Chinese teachers emphasize strategies such as reinventing a concept, verbalizing a concept, and using examples and comparisons for analogical reasoning. These findings draw on the perspective of classroom practitioners to inform the long-debated issue of the meaning of mathematical understanding and ways to achieve mathematical understanding.     

Modeling the influences of upper-elementary school students’ digital reading literacy,socioeconomic factors,and self-regulated learning strategies

Background: Reading is an interactive and constructive process of making meaning by engaging a variety of materials and sources and by participating in reading communities at school or in daily life.

Aim: The purpose of this study was to explore the factors affecting digital reading literacy among upper-elementary school students.

Method: A 3-stage stratified cluster sampling was implemented that resulted in a sample of 592 upper-elementary students from 29 classes in 7 schools. Self-Regulated Learning Strategies Assessment (S-RLSA), Digital Reading Literacy Assessment (DRLA), and student reports of their parents’ education backgrounds were used to collect data on the outcome and predictor variables. Interpretation of these data involved two highly regarded statistical techniques. First, structural equation modeling was used to explore relationships amongst the constructs. Second, multi-group invariance (MI) analyses were used to assess the influence of parental education and self-regulated learning strategies on students’ digital reading literacy.

Results: Enriching students’ family learning resources and strengthening their self-regulated learning abilities could have very important influences on promoting upper-elementary school students' digital reading literacy -webpage information retrieval, reading and communication abilities.

Conclusions: This study also provides information on how teachers can address student resources to improve digital reading literacy and self-regulated strategies.     

Teacher capacity for and beliefs about data-driven decision making: A literature review of international research

Data-driven decision making continues to be a growing educational reform initiative across the globe. The effective use of data requires that teachers develop the knowledge and skills to analyze and use data to improve instruction. The purpose of this article is to examine teachers’ capacity for and beliefs about data use. These issues are examined through a review of research in the past decade. We find that teachers’ beliefs about and capacity for data use are often not connected within the literature or in practice, but we argue they are the heart of the connection between data and instructional change. Teachers’ capacity to use data and their beliefs about data use are shaped within their professional communities, in training sessions, and in their interactions with coaches, consultants, and principals. However, efforts to develop teachers’ capacity for data use often fall short of their goals. Correspondingly, teachers have varied beliefs about data use, and some feel they lack the ability to use data to inform instruction. In order to be more successful, capacity building should directly address teachers’ beliefs, and data use must be decoupled from external accountability demands and involve a variety of information on student learning.