Employment profiles and compensation

Conclusions The authors’ expectations are that AECT members and other educational technologists will use the information presented to establish or increase their own levels of compensation (or the compensation levels of those they supervise). Knowledge of the education levels, experience, salaries, and work motivation factors of fellow educational technologists may enable you to negotiate more effectively and fairly. The AECT salary survey described in this article was commissioned and conducted prior to James A. Pershing becoming Editor-in-Chief of TechTrends.     

Differential Item Functioning Effect Size From the Multigroup Confirmatory Factor Analysis for a Meta-Analysis: A Simulation Study

This study presents a new approach to synthesizing differential item functioning (DIF) effect size: First, using correlation matrices from each study, we perform a multigroup confirmatory factor analysis (MGCFA) that examines measurement invariance of a test item between two subgroups (i.e., focal and reference groups). Then we synthesize, across the studies, the differences in the estimated factor loadings between the two subgroups, resulting in a meta-analytic summary of the MGCFA effect sizes (MGCFA-ES). The performance of this new approach was examined using a Monte Carlo simulation, where we created 108 conditions by four factors: (1) three levels of item difficulty, (2) four magnitudes of DIF, (3) three levels of sample size, and (4) three types of correlation matrix (tetrachoric, adjusted Pearson, and Pearson). Results indicate that when MGCFA is fitted to tetrachoric correlation matrices, the meta-analytic summary of the MGCFA-ES performed best in terms of bias and mean square error values, 95% confidence interval coverages, empirical standard errors, Type I error rates, and statistical power; and reasonably well with adjusted Pearson correlation matrices. In addition, when tetrachoric correlation matrices are used, a meta-analytic summary of the MGCFA-ES performed well, particularly, under the condition that a high difficulty item with a large DIF was administered to a large sample size. Our result offers an option for synthesizing the magnitude of DIF on a flagged item across studies in practice.     

Neural-network-based decentralized fault-tolerant control for a class of nonlinear large-scale systems with unknown time-delayed interaction faults

This paper proposes an adaptive approximation design for the decentralized fault-tolerant control for a class of nonlinear large-scale systems with unknown multiple time-delayed interaction faults. The magnitude and occurrence time of the multiple faults are unknown. The function approximation technique using neural networks is employed to adaptively compensate for the unknown time-delayed nonlinear effects and changes in model dynamics due to the faults. A decentralized memoryless adaptive fault-tolerant (AFT) control system is designed with prescribed performance bounds. Therefore, the proposed controller guarantees the transient performance of tracking errors at the moments when unexpected changes of system dynamics occur. The weights for neural networks and the bounds of residual approximation errors are estimated by using adaptive laws derived from the Lyapunov stability theorem. It is also proved that all tracking errors are preserved within the prescribed performance bounds. A simulation example is provided to illustrate the effectiveness of the proposed AFT control scheme.     

Online Versus Offline in the United States: Are the Media Shrinking?

We find that combined revenues for 10 major media in the United States have steadily declined as a proportion of overall economic activity or gross domestic product (GDP) from 1999 to at least 2009 (the latest year for which we have complete data). For individual media, we find a generally consistent pattern in which increasing revenues from Internet distribution are exceeded by declines in revenues from established distribution channels, with the exception of television and video games, whose revenues have so far kept pace with GDP. We also report a marked overall shift from advertiser to direct payment support for the media industries over this period. We consider four possible reasons for these revenue trends: shifts in consumer media usage, reduced appropriability due to more difficult copyright protection, inadequate advertising business models, and reduced costs due to more efficient Internet distribution. Our analysis suggests we may be entering an era of a declining size of media industries in terms of conventional measures, but not necessarily a falling supply of media products themselves.     

A novel term weighting scheme based on discrimination power obtained from past retrieval results

Term weighting for document ranking and retrieval has been an important research topic in information retrieval for decades. We propose a novel term weighting method based on a hypothesis that a term’s role in accumulated retrieval sessions in the past affects its general importance regardless. It utilizes availability of past retrieval results consisting of the queries that contain a particular term, retrieved documents, and their relevance judgments. A term’s evidential weight, as we propose in this paper, depends on the degree to which the mean frequency values for the relevant and non-relevant document distributions in the past are different. More precisely, it takes into account the rankings and similarity values of the relevant and non-relevant documents. Our experimental result using standard test collections shows that the proposed term weighting scheme improves conventional TF^*IDF and language model based schemes. It indicates that evidential term weights bring in a new aspect of term importance and complement the collection statistics based on TF^*IDF. We also show how the proposed term weighting scheme based on the notion of evidential weights are related to the well-known weighting schemes based on language modeling and probabilistic models.     

Robust event-driven tracking control with preassigned performance for uncertain input-quantized nonlinear pure-feedback systems

This paper presents a simplified design methodology for robust event-driven tracking control of uncertain nonlinear pure-feedback systems with input quantization. All nonlinearities and quantization parameters are assumed to be completely unknown. Different from the existing event-driven control approaches for systems with completely unknown nonlinearities, the main contribution of this paper is to design a simple event-based tracking scheme with preassigned performance, without the use of adaptive function approximators and adaptive mirror models. It is shown in the Lyapunov sense that the proposed event-driven low-complexity tracker consisting of nonlinearly transformed error surfaces and a triggering condition can achieve the preselected transient and steady-state performance of control errors in the presence of the input quantization.     

Student–university relationships and reputation: a study of the links between key factors fostering students’ supportive behavioral intentions towards their university

Focusing on academic institutions in higher education as the research context, this study examined the relations of key factors affecting students’ supportive behavioral intentions toward the university (e.g., giving gifts as alumni, continuing education, and giving referrals regarding the university). Based on the literature from various disciplines, this study proposed four factors are critical influencing such intentions: (1) students’ communication behavior with the university, (2) perceived quality of educational experience, (3) evaluations of the relationship with the university, and (4) university reputation. The data in this study were collected using a survey of current undergraduate students (N = 336) who were attending a private university in Seoul during Fall 2005. Structural equation modeling (SEM) was used to analyze the proposed model. Regarding overall results, the proposed model can be retained as a valid model based on data-model fits: Eight hypotheses were supported in this study, but not the effect of students’ educational experience on university reputation. The findings suggest that to foster students’ supportive behavior, universities need to cultivate a good relationship with their students and to obtain favorable reputation held by students, while ensuring active communication behavior of students and the quality of students’ educational experience.

A robust low-complexity tracker design with preassigned performance for uncertain high-order nonlinear systems with unknown time-varying delays and high powers

A robust low-complexity design methodology is presented for global tracking of uncertain high-order nonlinear systems with unknown time-varying delays. In contrast to the existing literature, this paper assumes that nonlinear bounding functions of time-delay nonlinearities and high powers of virtual and actual control variables are unknown. Furthermore, a delay-independent tracking scheme using nonlinearly transformed error surfaces is simply designed without the knowledge of nonlinear bounding functions of model nonlinearities, the adaptive technique, and the calculation of repeated time derivatives of certain signals. Thus, the proposed tracker is implemented with low complexity. It is recursively shown that the tracking error is preserved within the predefined bounds of transient and steady-state performance in the Lyapunov sense.     

Cultivating borrowed futures: the politics of neoliberal loanwords in South Korean cross-national policy borrowing

This paper examines the politics of policy-borrowing in Korean education. I use the term ‘loanwords’ as a metaphor for the practice in some Korean educational sectors of using borrowed English-origin educational rhetoric to create actual policy reform. I argue that discourses of choice and diversity, as loanwords, are initially bifurcated into progressivist and neoliberal policies; recently, they have been used to highlight particular aspects of market-based policies that are advantageous to particular social groups. I also demonstrate that the upper-class tends to make use of the terms choice and diversity in ways aligned with neoliberal perspectives in order to validate the pursuit of privileged opportunities, such as the right to choose to attend an elite high school.