基于PCA的安徽省上市公司经营业绩分析

现有文献对上市公司的经营业绩评价主要强调财务指标,而较少涉及反映企业成长特征的非财务指标。本文在重视财务指标的基础上,强调影响企业长期经营业绩的非财务指标的作用,利用2010年安徽省60家上市公司的经营数据进行了实证分析,得出的结论为:安徽省上市公司的盈利能力整体不高,还有较大的上升空间;从企业生长周期来看,安徽省的上市公司仍处于成长阶段,但资产管理能力较好。     

Comparisons of two statistical approaches to study growth curves: The multilevel model and the latent curve analysis

This article compares two statistical approaches for modeling growth across time. The two statistical approaches are the multilevel model (MLM) and latent curve analysis (LCA), which have been proposed to depict change or growth adequately. These two approaches were compared in terms of the estimation of growth profiles represented by the parameters of initial status and the rate of growth. A longitudinal data set obtained from a school‐based substance‐use prevention trial for adolescents was used to illustrate the similarities and differences between the two approaches. The results indicated that the two approaches yielded very compatible results. The parameter estimates associated with regression weights are the same, whereas those associated with variances and covariances are similar. The MLM approach is easier for model specification and is more efficient computationally in yielding results. The LCA approach, however, has the advantage of providing model evaluation, that is, an overall test of goodness of fit, and is more flexible in modeling and hypothesis testing as demonstrated in this study.     

Multidimensional Scaling Analysis of Growth and Change

Latent growth curve modeling provides a powerful and flexible tool for researchers to study individual differences in change as well as the correlates and predictors of change. Recent developments in estimation and hypothesis testing procedures are largely based on confirmatory structural equation approaches. In this article, an alternative exploratory approach is proposed for the analysis of growth and change using multidimensional scaling (MDS). When applied to growth data, it is a growth pattern recognition technique that partitions individual differences into initial level and growth pattern components. When applied to other longitudinal data, it can be used to study change patterns. A math achievement data set is used to illustrate the growth modeling method and a mood variable is used to illustrate change modeling. The strengths and limitations of the MDS growth profile analysis are discussed.     

Cumulative Advantages and the Emergence of Social and Ethnic Inequality: Matthew Effects in Reading and Mathematics Development Within Elementary Schools?

This article examines the development of social and ethnic disparities in academic achievement in elementary schooling. It investigated whether reading and mathematics development in 136 mixed‐ability classes shows path‐dependent processes of cumulative advantage (Matthew effects) from Grades 4 to 6 (Grade 4 mean age = 10.62, SD = 0.57) resulting in growing inequality. Status‐dependent processes of cumulative advantage, their interaction with path‐dependent processes, and consequences for the degree of social and ethnic inequality are examined. Two complementary methods for analyzing multilevel data are used: growth curve and quasi‐simplex models. No evidence for a Matthew effect was found in either domain. A compensation effect emerged for reading, to the benefit of ethnic minorities. A fan‐spread effect was found for mathematics, partly attributable to status‐dependent processes of cumulative advantage.     

Repeated-measures analysis of variance in developmental research: selected issues

This paper presents a review of recent developments in statistical techniques for repeated-measures analysis of variance. Since the literature has emphasized the issue of mixed model assumptions and their violation, we present an updated perspective on the nature of these assumptions and their implications for mixed model, adjusted mixed model, or multivariate significance tests. However, the central theme of the review is that the validity of mixed model assumptions is but one consideration in selection of an appropriate method of repeated-measures ANOVA. In particular, we recommend the avoidance of omnibus significance tests in favor of specific planned comparisons whenever hypotheses more specific than the omnibus null hypothesis may be formulated a priori. The analyst must also consider whether multiple dependent measures are to be analyzed, and the paper discusses alternative approaches to true multivariate repeated-measures designs. It also includes discussion of other relevant issues, including a brief review of the strengths and weaknesses of commonly available statistical software when applied to the analysis of repeated-measures data.     

Measuring learning outcomes

The growing interest for measurement of learning outcomes relates to long lines of development in higher education, the request for accountability, intensified through international reforms and movements such as the development and implementation of qualifications frameworks. In this article, we discuss relevant literature on different approaches to measurement and how learning outcomes are measured, what kinds of learning outcomes are measured, and why learning outcomes are measured. Three dimensions are used to structure the literature: Whether the approaches emphasise generic or disciplinary skills and competence, self‐assessment or more objective test based measures (including grades), and how the issue of the contribution from the education program or institution (the value‐added) are discussed. It is pointed out that large scales initiatives that compare institutions and even nations seem to fall short because of the implicit and explicit differences in context, whilst small‐scale approaches suffer from a lack of relevance outside local contexts. In addition, competence (actual level of performance) is often confused with learning (gain and development) in many approaches, laying the ground for false assumptions about institutional process‐quality in higher education.     

山东省对外开放与经济增长关系的实证分析

随着世界经济一体化和经济全球化的不断推进,对外开放与一国或地区的经济发展的关系日益密切。根据山东省1985—2006年的有关数据,从定量的角度,采用回归分析方法、协整分析技术和格兰杰因果检验方法,实证研究了山东省对外开放与经济增长之间的关系。实证结果表明,山东省GDP增长、出口总额和外商直接投资三者之间存在长期稳定的均衡关系,经济增长与出口总额增长互为格兰杰原因,经济增长是实际利用外资额增长的格兰杰原因,但实际利用外资额增长不是经济增长的格兰杰原因。依据分析结论,提出了促进山东省对外开放与经济互动发展的建议。     

中国文学史初创期的"南黄北林"论

国人自著文学史自窦警凡始,对后来文学史著述产生巨大影响的是北方的林传甲和南方的黄人.林传甲的<中国文学史>接受了日本( )川种郎的影响,创造性少.黄人在文学史观上有较大的突破,不仅注意到文学发展的量变进程,也注意到文学史进程中的质变和突变,其文学观至今仍有现实价值和借鉴意义.但他的<中国文学史>因坊间没有印行,仅为东吴大学堂教本,故流传不广.     

Does Grading Method Influence Honours Degree Classification?

Variation in mark-spread is very evident in degree classification data provided by the Higher Education Statistics Agency (HESA). Previous empirical investigations suggested that, at the level of the module, the spread of results might, in some subjects, be influenced by the method of grading (percentage marking or shorter grade-point scale). The availability of degree classification data from HESA made it possible to test whether the effect perceived at module level carried through to the honours degree classification. The empirically-generated hypothesis was that subjects characterised by a relatively narrow spread under percentage marking would show a wider spread when a grade-point scale of around 20 divisions was used, with the effect being detectable in honours degree classification data. The hypothesis was tested, using HESA data for academic years 1994-95 to 1998-99, on those new universities in England and Wales for which the existence of an institution-wide grading approach could be established. Tests were undertaken at the level of the HESA subject area, and at the more fine-grained level of the individual subject where numbers permitted. Results from the analyses are mixed. The analyses have probably been influenced by weaknesses in the way that HESA has collected award data, but nevertheless suggest lines for further inquiry into a matter that is of importance for equity within institutions (especially where modular schemes are being operated) and more broadly across the higher education sector.     

Differentiating between and synthesizing quantitative,qualitative, and longitudinal research on polarized school cultures: a comment on Van Houtte (2006)

Van Houtte provides a valuable large‐sample quantitative analysis of differentiation and polarization processes between and within school cultures in Belgium. Such research across 34 secondary schools provides greater confidence that the findings in the ethnographic tradition for the differentiation–polarization theory are not due to idiosyncracies of the individual schools chosen. However, it is unhelpful to contrast her large‐sample approach with the ethnographic tradition by characterizing the former as quantitative and the latter as qualitative. Many ethnographic studies of secondary schools have employed quantitative methods. It is better to characterize her research as multi‐site and the ethnographic tradition as case‐study. This illuminates how the two methodologies can be more constructively synthesized. Within large sample multi‐site approaches some selection of in‐depth case studies, together with longitudinal data analysis, are needed to disentangle socio‐economic class effects from differentiation effects in order to determine causality.     

The I files,the truth is out there: science teachers’ constructs of inquiry

This article is concerned with the personal constructs of science teachers about inquiry in selected schools in the Yorkshire and the Humber region of England. While there is a large volume of existing literature which advocates the use of inquiry in the science classroom to enhance students' engagement with, and learning of science, relatively few of these studies represent teachers' voice. Therefore, we believe that it is important and distinctive to report teachers' constructs of inquiry and related concerns regarding its use in the science classroom. We identify the key constructs from 10 participating teachers and discuss these amongst a backdrop of policy implications for inquiry approaches in English secondary school science classrooms. Personal Construct Theory was used to underpin the study and frame data collection and analysis. Key findings show that the teachers identify an inquiry approach as being effective in stimulating students' independent learning and interest in science but issues such as time and confidence inhibit their deployment of inquiry approaches.     

Learning thoughtful reflection in teacher education

The notion of reflection has become an object of attention in education, but the research on this topic is often reduced to mere reflective practice. A relevant part of educational literature portrays reflection as a wholly beneficial practice for practitioners, but also for researchers. In the nursing field, in particular, reflection is largely practised and deeply examined. Reflection is specifically encouraged in teacher education, where ‘how-to’ manuals are widely used to explain strategies for turning teachers into reflective practitioners. In some cases, a specific kind of reflective approach is proposed, such as critical reflection. From the analysis of this technical literature, I observe that a wide range of approaches for fostering reflection have been applied, but little research evidence shows how effective these approaches are. Taking this problem into account, this article presents a research study on reflection. It first introduces a specific and unusual concept of reflection – that of phenomenological conception – and then goes on to develop an empirical investigation that enacts a phenomenological method of inquiry and is aimed at exploring the potential of the use of journal writing as a tool for enhancing reflection, and documents the data that emerged. The research was developed in a university context where the student teachers were asked to ‘reflect on the life of the mind’, in order to learn how to take a reflective stance. The student teachers wrote entries in a reflective journal in which they were requested to describe the lived experiences of the mind as they came to their reflective attention. The data emerging from the experience were made sense of through a qualitative method of analysis. The findings of the research are useful for designing an effective method for enhancing reflective practice.

     

Transformative Readings: Harry Potter Fan Fiction,Trans/Queer Reader Response,and J. K. Rowling

The politics of children’s literature and the actors surrounding it have never been more visible than they are now, in the digital age. As one of the first children’s series to gain widespread popularity concurrently with the spread of the internet, the Harry Potter septet arrived on the global stage at the perfect moment to develop an avid, connected fandom. But the fandom has laid bare the many conflicting ideologies of the fans themselves and of the actors surrounding the texts. This article examines the contentious issue of gender nonnormativity and its relation to the Harry Potter texts, the queer/trans reading practices and political resistance common to the fandom, and the ongoing disagreements over gender, made visible on social media, between Rowling and the fans of her series. The article discusses the Harry Potter novels’ varied and conflicting ideologies; queer/trans readings of the Potter septet, including both invitations and resistances to queer/trans reading by Rowling herself; how gender is queered and queried in and through fan fiction; and finally, the recent hostilities between Rowling and her fans. It concludes by discussing the worsening relationship between Rowling and her fans and highlighting how fans are using their collective power to undermine Rowling’s gender politics through fan fiction. By doing so, the article traces the complex politics of the reception of books for young people in the digital age, demonstrating that authors’ powerful voices continue to shape readers’ responses to texts long after their publication but showing, too, that readers often resist authors’ attempts to influence not only their textual interpretations but their politics.

     

Shaking Religious Education: A New Look At The Literature

This article offers an analysis of religious education practice through the literature that informs it. It engages Derrida's critique of the “metaphysics of presence” (1982a) to develop a theoretical framework for a new look at the ways in which different approaches to religious education represent religion and racial difference. The article specifically examines literature that has impacted mainstream Christian and “secular” religious education in South Australia from the 1970s until today. The article concludes by proposing a new approach to racial, cultural, and religious difference in religious education—one that begins to understand religious education's engagement with Others in terms of ethical questions, deliberation, and a radical openness to what is unforeseeable. It argues for the need for religious educators to begin to actively and deliberatively engage with “who” and “what” has traditionally been absent from multireligious approaches to religious education.     

IEEE 802.11协议直扩技术的实现

802.11标准直扩技术主要是对网络的物理层(PH)和媒质访问控制层(MAC)进行了规定,其中对MAC层的规定是重点.同一物理层上可以互操作,逻辑链路控制层(LLC)是一致的,即MAC层以下对网络应用是透明的.这样就使得无线网的"(同网段内)多点接入"和"多网段互连",易于质优价廉地实现.     

Reaching the students that student‐centred learning cannot reach

Student‐centred learning has the potential to engage a more academically diverse student body than the more conventional teacher‐centred approaches. In spite of the evidence in favour of student‐centred learning, a recent study showed that it was ineffective for around 30% of undergraduates in a large and diverse group studying business operations management. The possible reasons for this are explored in two ways. First, the literature relating to student engagement and participation is reviewed from three different perspectives: the sociological, the epistemological and the approaches to learning perspectives. Second, all three perspectives are applied to data generated from the original study within the context of a post‐1992 university. The advantages of a three‐perspective approach over a single‐perspective approach are discussed. Finally, the development of a holistic model integrating all three perspectives is called for, to be used as a guide for further empirical research into student engagement and as a tool for evaluating and developing inclusive and engaging learning environments.     

Using Monte Carlo Normal Distributions to Evaluate Structural Models With Nonnormal Data

Statistical theories of goodness-of-fit tests in structural equation modeling are based on asymptotic distributions of test statistics. When the model includes a large number of variables or the population is not from a multivariate normal distribution, the asymptotic distributions do not approximate the distribution of the test statistics very well at small sample sizes. A variety of methods have been developed to improve the accuracy of hypothesis testing at small sample sizes. However, all these methods have their limitations, specially for nonnormal distributed data. We propose a Monte Carlo test that is able to control Type I error with more accuracy compared to existing approaches in both normal and nonnormally distributed data at small sample sizes. Extensive simulation studies show that the suggested Monte Carlo test has a more accurate observed significance level as compared to other tests with a reasonable power to reject misspecified models.     

Two New Approaches to Assessing Differential Item Functioning: Standardization and the Mantel--Haenszel Method

The standardization and Mantel-Haenszel approaches to the assessment of differential item functioning (DIF) are described and compared. For rightwrong scoring of items, these two approaches, which emphasize the importance of comparing comparable groups of examinees, use the same data base for analysis, namely, a 2 (Group) x 2 (Item Score: Correct or Incorrect) x S (Score Level) contingency table for each item studied. The two procedures differ with respect to how they operate on these basic data tables to compare the performance of the two groups of examinees. Whereas the operations employed by Mantel-Haenszel are motivated by statistical power considerations, the operations employed by standardization are motivated by datainterpretation considerations. These differences in operation culminate in different measures of DIF effect-size that are very highly related indicators of degree of departure from the null hypothesis of no DIF.     

报告文学调查采访的理论来源与特点

报告文学是“行走的文学”。调查采访是报告文学写作十分重要的环节,其基本理论与方法主要来源有三种：新闻学的采访理论与方法;社会学的“田野调查”理论与方法;文学的生活积累与体验论。报告文学的采访和调查与新闻采访、田野调查,因各自的目的差异、文本规范要求的不同,呈现出的相对特点是明显的。     

Towards adaptive open learning environments: Evaluating the precision of identifying learning styles by tracking learners’ behaviours

Open learning represents a new form of online learning where courses are provided freely online for large numbers of learners. MOOCs are examples of this form of learning. The authors see an opportunity for personalising open learning environments by adapting to learners’ learning styles and providing adaptive support to meet individual learner needs and preferences. Identifying learning styles of learners in open learning environments is crucial to providing adaptive support. Learning styles refer to the manner in which learners receive and perceive information. In the literature, a number of learning style models have been proposed. The Felder and Silverman Learning Styles Model (FSLSM) has been selected as the most appropriate model for open learning. In previous studies two approaches have been used to automatically identify learning styles based on the FSLSM. These approaches are known as the data-driven method and the literature-based method. In the literature, the literature-based method has been shown to be more accurate in identifying learning styles. This method relies on tracking learners’ interactions with the provided learning objects based on a set of pre-determined patterns that help in inferring learning styles. The patterns are monitored based on pre-identified threshold values. This paper aims to apply the literature-based method to open learning environments and introduce the optimal patterns and threshold values for identifying learning styles based on the FSLSM. To achieve this aim, a study was conducted whereby a prototype that simulates the open learning environment was developed and piloted on an undergraduate IT course so that learner behaviour could be tracked and data could be collected. Next, different sets of threshold values from the literature were considered along with some updated threshold values considering the context of open learning environments, and the precision of identifying learning styles was calculated. Eighty-three students participated in the study and used the developed prototype. Precision results from different threshold values presented in the literature along with customised threshold values for this study are reported and analysed in this paper. It is shown that threshold values derived from literature and customised to suit open learning environments provide a high level of accuracy in identifying learning styles. The paper presents the first study of its kind in evaluating threshold values and precision in identifying learning styles based on the FSLSM in open learning environments. The results are promising and indicate that the proposed methodology is efficient in detecting learning styles in open learning environments and useful for developing an adaptive framework.