概念图的布局算法研究

概念图是一种有效的知识可视化工具,而概述图的布局是影响其信息传递能力的重要因素,因此布局算法是实现概念图工具的重要技术基础.本文在Sugiyama层次布局算法的基础上,针对概念图的特点和布局要求,提出了一种概念图的布局算法：首先对概念图的概念节点和关系节点进行简化处理,然后应用Sugiyama层次布局算法的第一步（分层）,并对图中的关系节点进行特殊处理,调整分层,最后应用Sugiyama层次布局算法的“交叉减少”和“坐标分配”模块,得出概念图各个节点（包括概念节点、关系节点和虚拟节点）的坐标,最终得出概念图的布局.该算法已通过编程实现,并成功应用于我们自主研发的概念图工具软件中.     

解布局问题的模拟退火算法

本文以简化模型为例，给出了用模拟退火算法解布局问题的一般形式，基本步骤以及罚函数的使用方法，所给算法在选用适当的数据结构后即可求解复杂的布局问题，有很强的适应性和灵活性。     

一种求解RSMT布线问题的PSO算法

最小直角斯坦纳树（RSMT）问题是超大规模集成电路布线中的重要问题之一,是典型的NP困难组合优化问题.为了有效地解决超大规模集成电路布线中的RSMT问题,提出一种粒子群优化算法,借助直角Steiner树的一些性质,采用Steiner点编码方案,寻找优化的Steiner点位置以减少直角Steiner树的长度.对几组布线模型实例进行了仿真测试,表明了该算法的有效性.     

4种VLSI标准单元初始布局生成算法及其比较

由于超大规模集成电路（VLSI）标准单元布局问题的高度复杂性,选择适当的初始布局生成算法成为能否在合理的运行时间内获得高质量布局结果的关键因素之一.首先介绍了VLSI标准单元布局问题和优化目标的数学模型.在此数学模型的基础上,给出了4种标准单元初始布局生成算法基本思想及其详细的步骤.对这4种初始布局算法在标准测试例子上的实验结果进行比较,分析它们作为启发式算法初始种群的有效性.     

基于空间分割的求解布局几何可行域的算法

通过研究空间布局问题,提出了一种基于空间分割的求解可行域的算法。布局物体的可行域与布局物体本身密切相关,通过缩小的布局空间和所有扩张后的已布入的布局物体进行减运算,即可获得待布物体的可行域。分析和实例表明：该算法简单有效,有着较强的应用前景。     

VLSI/ASIC进入亚微米深亚微米后出现的问题及解决的办法

这些年超大规模集成电路得到了飞速的发展,与此同时,随着器件特征尺寸的减小,尤其是进入深亚微米后出现了一系列新的问题。本文主要阐述了超大规模集成电路进入深亚微米后在设计方法和工艺上出现的问题,以及解决的方法。     

专用集成电路(ASIC)的现状与分析

本文阐述了专用集成电路(ASIC)的主要原理,包括专用集成电路的定义、主要技术特点及其飞速发展的原因.论文最后分析和评述了ASIC技术的技术现状和发展趋势.     

面向21世纪计算机专业硬件教学改革的研究

本文介绍了当前计算机专业硬件教学的形势,提出了以超大规模集成电路应用技术为主的硬件课程教学改革的思想,给出了面向21世纪计算机专业硬件教学改革具体实施方案。     

纠两错的RS码在FPGA上的实现

介绍了RS码的结构和一般译码方法,重点讨论了RS(15,11)的译码方法。我们根据PS码的循环性采用了step-by-step算法,使占用硬件资源最少从而适合在VLSI实现。并用ALTERA公司的FLEX10K10器件实现了RS(15,11)纠错码。经试验测试,对码组中任意不多于两个的符号错误都可以给予纠正,且运行可靠。     

关于设备布局的最短路径算法模型

生产车间的设备布局设计是一个组合优化的问题。具有NP完全(Nondeterministic Polynomial Complete)、非线性等特性,常规方法较难以求解。本文提出实际路线运算法结合基因算法来求解最优设备布局结果,利用遗传算法探索生产车间设备布局问题时适值函数的确定方法。     

VLSI标准单元布局遗传交叉算子比较研究

遗传算法的成功之处在于其交叉、变异等进化机理,交叉算子性能对算法的整体性能有决定性的影响,因而成为了设计大规模问题遗传算法的关键因素.首先简要介绍VLSI标准单元布局问题定义及其染色体编码,给出4种主要交叉算子的基本思想及其算法步骤,并对其中循环交叉算子进行改进.而后使用标准测试例子对这4种交叉算子的性能进行深入的实验比较,分析交叉算子特征与性能的关联性,总结了高性能交叉算子的设计思想.改进型限定长度循环交叉算子的性能实验结果验证了该设计思想的有效性.     

Class placement and competence attainment among students with special educational needs

John Olav Myklebust is Professor of Sociology at Volda University College in Norway. In this article, he discusses his analysis of data emerging from a longitudinal study of 494 young people with special educational needs who have been followed over a period of six years. This analysis focuses on the attainments of these students during their time in upper secondary education and asks whether placement in special or ordinary mainstream class groupings is more beneficial. The results indicate that students receiving special support in ordinary classes obtain vocational or academic qualifications more often than students in special classes. Professor Myklebust pursues his analysis by looking at the influence of a number of other variables, including assessments of functional level, family stability and gender. He concludes that the relationship between attainment and placement in an ordinary classroom does not change, even when these variables are taken into account, and argues that his findings provide further support for the inclusion of learners with special educational needs in ordinary mainstream classes.     

Enhancing the work placement experience of international students: towards a support framework

This article reports the findings from an institutional case study into the work placement experience of undergraduate international students studying at a UK-based university. Given the centrality and importance of the employability and internationalisation agendas in higher education, little published literature considers both and how they impact upon the work placement experience of international students. With past increases in international student recruitment numbers and the drive for students, regardless of their nationality, to gain work experience, there is a need for institutions to better understand work placement from the international students’ perspective. Findings revealed that challenges exist in finding and securing work placement, with critical themes emerging to include placement information, visa rules, culture differences, prior work experience, academic preparation for placement and academic writing ability. A support framework is proposed to assist institutions to consider how they could align their practices to meet international students’ work placement and employability needs.     

School placement and conductive education: the experiences of education administrators

A placement at the National Institute of Conductive Education (NICE) in Birmingham for children with motor disorders is strongly preferred over mainstream or special schools by some parents, but it has been noted that this is usually refused following the current statementing process. Although funding constraints have been articulated, Angela Morgan, a Research Fellow at the Wolverhampton University Policy Research Institute, and Kevin Hogan, also at the University of Wolverhampton, contend in this article that other explanations are possible, as variability remains in placement decisions. The experiences of education administrators working within the special educational needs departments of local education authorities who make the ultimate decision regarding school placement have hitherto been unexplored. This study offers findings from an exploratory qualitative study, which suggests that administrators are working from disparate understandings of conductive education within an arena fraught with conflict. Recommendations derived from the study include further in-service training for education administrators and prior training for individuals seeking a career in education administration to enhance collaborative working partnerships between administrators and parents.     

The placement of secondary school students with Statements of special educational needs in the more diversified system of English secondary schooling

This article examines the pattern of placement of students with significant special educational needs at Statement and School Action Plus levels in English secondary schools, comparing sponsored and converter academies, maintained schools and the newly created free schools, studio schools and university technical colleges for 2013 and 2014. The analysis shows a clear pattern of differences: converter academies (which are governed by their own governing body) had significantly lower proportions of students with significant special educational needs overall than maintained (those remaining under local authority management) and sponsored academies (those considered to be weak/failing schools forced to become academies with outside sponsors that oversee the schools). There was a similar pattern of findings for most areas of special educational needs, except visual impairment and autistic spectrum disorder. The pattern of placement of students with Statements in the newly created free schools also showed that some free schools have unusually high proportions of students with special educational needs. These findings are discussed in terms of the increasing stratification of English secondary schools and the potential of small secondary schools to be more inclusive.     

How the existence of special schools affects the placement of students with special needs in inclusive primary schools

Although inclusion is the declared goal, the transition from a system based on special schools to an inclusive school system has only been progressing very slowly in individual countries. In an evolving school system, the existing special schools keep struggling to justify their existence. This study investigates the regional distribution effects based on official school data and shows the influence of a pull effect on special schools as a distance effect of special schools affecting the placement of students. For this purpose, official school statistics including all students at special and regular schools in the years 2010, 2015 and 2020 (N = 11 280 040) are evaluated in a spatiotemporal comparison using Educational Data Mining. In a hierarchical regression model on school placement in inclusive schools, the distance between primary and special schools has the highest influence (β = 0.48) on the inclusion rate (i.e., the proportion of students with special needs who are educated in regular schools in relation to all students with disabilities), along with the size (β = −0.14) and the density of special schools in a district (β = −0.12). The effects differ according to the population density of the region and are stronger in large cities. When the proportion of students with and without SEN in regular schools is considered (support rate), the density of special schools has the greatest impact on school placement (ß = 43.44). Self-preservation of schools, traditional funding systems and regional differences between urban and rural areas are discussed as possible reasons.     

School placement and classroom participation among children with disabilities in primary school in Norway: a longitudinal study

The purpose of this paper is to address changes in school placement and classroom participation with respect to children with disabilities of primary school age in Norway, as well as examining the factors which explain variation in school placement and classroom participation. School placement refers to whether children with disabilities attend regular school, while classroom participation refers to time spent in regular classrooms at regular schools. The analysis is based on longitudinal data drawn from surveys undertaken in 2003 and 2006, of parents of children with disabilities. Present findings suggest there are no major changes in school placement during primary school years, which is contrary to earlier findings. However, the amount of time children with disability are absent from regular classes does increase significantly as the children become older. Size of municipality population, type of disability and degree of impairment are the main factors which have an impact on school placement. In addition to these, the amount of special education also has an impact on classroom participation. There are small changes in mechanisms that lead children out of both regular schools and classrooms, during their primary school years. However, some of the identified factors strengthen in importance as the children become older. The apparent policy change for older children, from special school placement to an “out of class” practice, is discussed. It could be seen as regular schools’ adaptation to the tension between the prevailing ideology of inclusion and schools’ maintenance of existing practice.     

Factors that explain placement decisions for students with multiple disabilities: findings from national data

The Special Education Elementary Longitudinal Study data set was utilised to examine the potential influences on placement decisions for students with multiple disabilities in the US. The sample consisted of 415 students. Specifically, the study investigated whether factors including students’ prior special education experiences, parental involvement, parental expectations and educational risk factors explain the placement of students in classrooms. Results indicate significant relations between the explanatory variables and the hours spent daily in general education classrooms. However, only two variables, parents’ education and receipt of early childhood special education services, were significantly associated with the dichotomised outcome of whether or not a child received any academic instruction in a general education classroom. Research limitations and implications for future research, policy and practice in the international context are discussed.     

The use of a custom-built online environment for communication with and support of student-teachers during school placement

School Placement is recognised as a central component of Initial Teacher Education (ITE) programmes for the professional development and personal growth of student-teachers. It is also acknowledged to be a particularly challenging time for students during which they require support and guidance from their ITE tutors. In this regard, online environments hold much potential to facilitate greater communication between student-teachers and tutors during school placements. This paper considers the communicative features of a custom-built online environment for teacher education in the context of a concurrent ITE degree. It identifies a number of positive outcomes from the use of this system with regard to communication between student-teachers and their tutors. These include a more sustained and dialogical engagement between student-teacher and tutor throughout the duration of the placement, enhanced levels and quality of support that tutors can extend to student-teachers while on placement and more productive face-to-face communication between tutors and students.