Local influence on a test of linear hypothesis in multiple regression model

SUMMARY The local influence method is adapted to investigate the influence of observations on testing the linear hypothesis. The method provides information about individually or jointly influential observations in performing the test, which the usual diagnostic methods do not yield. An example is presented for illustration of the method.     

Inter-organizational information systems visibility in buyer–supplier relationships: The case of telecommunication equipment component manufacturing industry

The concept and operation of supply chain (SC) visibility remain underexplored questions in supply chain management, as is the question of the facilitating role of inter-organizational information systems (IOIS) in achieving SC visibility. This paper seeks to elaborate on the novel concept of IOIS visibility and to explore the antecedents and consequences of IOIS visibility. Investigating SC cooperation from the perspectives of both partners (buyers and suppliers) is important, especially when channel partners depend on each other and when asymmetries in IOIS visibility can exist.     

The longitudinal effects of parental monitoring and self-control on depression in Korean adolescents: A multivariate latent growth approach

The purpose of this study was to examine the longitudinal effects of parental monitoring and self-control on depression. To address this purpose, this study investigated the interrelationships among depression, perceived parental monitoring, and self-control—as well as their developmental changes from the eighth to the twelfth grades—by repeated assessment of 3449 Korean adolescents. The data from Korea Youth Panel Survey (KYPS) of the eighth graders who were followed for five years were analyzed using latent growth modeling. The univariate latent growth models showed that adolescents experience an increase in both parental monitoring and self-control but a decline in depression over the five years. In addition, the multivariate latent growth model suggested that the initial level of parental monitoring had significant effects, both directly and indirectly through self-control, on the initial level of depression. The linear changes in parental monitoring were associated with the linear changes in self-control; likewise, the linear changes in self-control were related to those in depression. These results imply that parental monitoring and self-control need to be emphasized as a strategy in order to prevent or alleviate adolescents' depression.     

POSTMODERN CONSUMER CULTURE WITHOUT POSTMODERNITY: COPYING THE CRISIS OF SIGNIFICATION

The purpose of this study was to interpret the meaning of the postmodern discourse produced by Korean television advertisements, by categorizing postmodern television advertisements and describing their representations and images of reality in detail. Considering the production process of Korean postmodern advertisements, the study raised a question: How can we interpret the phenomena of imitating and assimilating the style of advertisements from the reservoir of postmodern signifiers, while not taking into account the values, ideas and ways of thinking implicit in such advertisements?

There are two ways of interpretation. First, it would be an effect of structural dependence, in which postmodern consumer cultural forms are replicated and replace local products with mass-produced goods. The narratives of postmodern advertisements serve as the catalyst to introduce these advertisements and to teach the grammar of international advertising. Second, the assimilation of postmodern advertisements in Korean television means a newly emergent hybrid culture. Because the target of postmodern advertisements is the young consumer, the producers adopt postmodern tastes and styles, inserting and translating their roots into local forms. The study concluded that it may be more appropriate not to choose one of these interpretations as a single correct theory; it is better to look at the articulation of different forces and processes within a field of interconnections among mediascape, financescape and technoscape.     

On the functional form of temporal discounting: An optimized adaptive test

The tendency to discount the value of future rewards has become one of the best-studied constructs in the behavioral sciences. Although hyperbolic discounting remains the dominant quantitative characterization of this phenomenon, a variety of models have been proposed and consensus around the one that most accurately describes behavior has been elusive. To help bring some clarity to this issue, we propose an Adaptive Design Optimization (ADO) method for fitting and comparing models of temporal discounting. We then conduct an ADO experiment aimed at discriminating among six popular models of temporal discounting. Rather than supporting a single underlying model, our results show that each model is inadequate in some way to describe the full range of behavior exhibited across subjects. The precision of results provided by ADO further identify specific properties of models, such as accommodating both increasing and decreasing impatience, that are mandatory to describe temporal discounting broadly.     

Accelerated Burn-In Procedures and System Maintenance Policies

Burn-in is a widely used engineering method which is adopted to eliminate defective items before they are shipped to customers or put into field operation. In order to shorten the burn-in process, burn-in is most often accomplished in an accelerated environment. However, there have been few probabilistic or stochastic models for the burn-in procedures in accelerated environment. In this article, under a new stochastic model for accelerated burn-in procedure, the problems of determining both optimal accelerated burn-in time and optimal replacement policy are considered. Components are burned-in under an accelerated environment, then those surviving the burn-in procedure are put into field operation and they are maintained under a replacement policy. The properties of the optimal accelerated burn-in time and optimal replacement policy are obtained and a numerical example which illustrates the usage of obtained results will be presented.     

A Numerical Likelihood-Based Approach to Combining Correlation Matrices

Numerical approaches to developing accurate and efficient approximations to combined likelihoods of population correlation matrices in meta-analysis under normality assumptions for the data are studied. The likelihood is expressed as a multiple integral over the unit cube in (p ? 1)-dimensional space, where p is the row and column dimensionality of the correlation matrix. Three types of computation are proposed as ways to calculate the likelihood for any population correlation matrix P. As an application, inference is explored concerning intercorrelations among math, spatial and verbal scores in a SAT exam. Comparisons are made with conventional methods.     

Effect of Trajectories of Friends' and Parents' School Involvement on Adolescents' Engagement and Achievement

In a sample of 527 academically at‐risk youth, we investigated trajectories of friends' and parents' school involvement across ages 12–14 and the joint contributions of these trajectories to adolescents' age 15 school engagement and academic achievement. Girls reported higher levels of friends' and parents' school involvement than boys. Both parents' and friends' school involvement declined across ages 12–14. Combined latent growth models and structural equation models showed effects of the trajectories of friends' and parents' school involvement on adolescents' age 15 school engagement and academic achievement, over and above adolescents' prior performance. These effects were additive rather than interactive. Strategies for enhancing parent involvement in school and students' affiliation with peers who are positively engaged in school are discussed.     

The influence in comparing covariance matrices

The influence measure for the likelihood ratio test for comparing two covariance matrices is derived using the influence curve approach under the normality assumption. The influence measure for testing the equality of covariance matrices against the arbitrariness of them is partitioned into three influence measures: one for testing the equality of covariance matrices against the proportionality of them, another for testing the proportionality against the equality of correlations between them and the other for testing the equality of correlations against the arbitrariness. This partition implies that an observation can be influential in performing some tests among the four tests but not in performing the remaining tests. Thus the partition is more informative than considering the influence measure for the test of equality alone. Each influence measure is useful for detecting outliers in performing the corresponding likelihood ratio test.     

Distance-based outlier detection for high dimension,low sample size data

Despite the popularity of high dimension, low sample size data analysis, there has not been enough attention to the sample integrity issue, in particular, a possibility of outliers in the data. A new outlier detection procedure for data with much larger dimensionality than the sample size is presented. The proposed method is motivated by asymptotic properties of high-dimensional distance measures. Empirical studies suggest that high-dimensional outlier detection is more likely to suffer from a swamping effect rather than a masking effect, thus yields more false positives than false negatives. We compare the proposed approaches with existing methods using simulated data from various population settings. A real data example is presented with a consideration on the implication of found outliers.