Multi-group Test Research Articles

Size recognition and adaptive grasping using an integration of actuating and sensing soft pneumatic gripper

Due to less appropriate sensors for representing the pose of soft robotic hand, the soft robotic hand usually works in an open loop control system. In this paper, only two simple sensors were used in a soft pneumatic gripper (SPG) control system to make it possess innervated-like ability. The control system was conducted with only two sensors, air pressure sensor and bending sensor where the air pressure sensor is able to detect grasping force and the bending sensor is able to detect grasping position The bending sensor was characterized by testing on pressure vs. bending and bending vs. size relationships. The principle of circular-shaped object size recognition was presented in Algorithm 1. Multi-group tests had been done on grasping different size and material objects, and test results had a strong effect on size recognition ability of the SPG. Finally, adaptive grasping control process was presented in Algorithm 2. The tests on grasping the same size objects had been done. The test results demonstrate that the SPG is able to maintain stable grasping state for a long time based on size recognition ability no matter what material the object is. At the same time, it had no effect on the grasping state at the time of existing disturbance, which had been verified by four different disturbance tests. The SPG will benefit the development of soft robotics field in picking and sorting fruits and vegetables, and an application of the SPG affixed on the home-made palletizing robot was described and conducted at last.

A comparison of fitness-case sampling methods for genetic programming

Genetic programming (GP) is an evolutionary computation paradigm for automatic program induction. GP has produced impressive results but it still needs to overcome some practical limitations, particularly its high computational cost, overfitting and excessive code growth. Recently, many researchers have proposed fitness-case sampling methods to overcome some of these problems, with mixed results in several limited tests. This paper presents an extensive comparative study of four fitness-case sampling methods, namely: Interleaved Sampling, Random Interleaved Sampling, Lexicase Selection and Keep-Worst Interleaved Sampling. The algorithms are compared on 11 symbolic regression problems and 11 supervised classification problems, using 10 synthetic benchmarks and 12 real-world data-sets. They are evaluated based on test performance, overfitting and average program size, comparing them with a standard GP search. Comparisons are carried out using non-parametric multigroup tests and post hoc pairwise statistical tests. The experimental results suggest that fitness-case sampling methods are particularly useful for difficult real-world symbolic regression problems, improving performance, reducing overfitting and limiting code growth. On the other hand, it seems that fitness-case sampling cannot improve upon GP performance when considering supervised binary classification.

Body Dissatisfaction and Mental Health Across Ethnic/Racial and Immigrant Groups: Implications for Marriage and Family Therapists

ABSTRACTThe purpose of this effort is to broaden the scope with which body dissatisfaction (BD) is viewed to inform the practices of MFTs. Associations between college students' BD and measures of depression, anxiety, self-esteem, and body image were tested using mean-level comparisons, path analysis, and multi-group tests by sex, across ethnic/racial groups, and across immigration status. Data were collected from N = 10,573 youth. There was evidence of significant mean level differences, and BD predicted internalizing symptoms while multi-group tests were largely invariant suggesting a more universal impact than dominant theoretical explanations (i.e. Objectification theory) posit.

Testing the Factorial Equivalence of the Collegiate Learning Assessment Performation Task Diagnostic Instrument Across Lower Class and Upper Class Predominantly Black College Students

Objective: This study was aimed at determining the external validity of the psychometric properties of a two-factor Collegiate Learning Assessment Performance Task Diagnostic Instrument (CLAPTDI) for use in assessing learning skills among predominantly black college students. The construct validity of the two factors CLAPTDI had been established in a previous study exploratory and confirmatory factor analyses. Establishing the external validity involved conducting a multi-group test of the measurement instrument’s factorial scores equivalence across panels of lower class and upper class students from a predominantly black college. Method: The study relied on a strict test of equivalence categorization by focusing on tests for invariance across the two groups with respect to factor loadings, intercepts, and error factor loadings by estimating the difference in chi-square goodness-of-fit statistic and comparative fit index (CFI). Sets of measurement and structural parameters were put to the test in a logically ordered and increasingly restrictive manner. Results: The analyses found that the CLAPTDI scale’s factorial measurement structure was invariant across lower class and upper class PBC students. Conclusion: The collegiate learning assessment performance task diagnostic instrument with two latent factors and five observed variables is a valid measurement scale for assessing the level of analytic reasoning and problem solving learning among predominantly black college students.

Understanding psychological processes of applicants’ job search

PurposeThe purpose of this paper is twofold. First, it empirically examines two theory-based models of applicants’ job search developed from planned happenstance theory (PHT) and theory of planned behavior (TPB). Second, it tests the cross-cultural compatibility of these models in Japan and Korea.Design/methodology/approachThe authors tested two theory-based job search models, PHT model and TPB model based on samples of college students from Japan (n=175) and Korea (n=172).FindingsThe results indicated that the TPB model was a significantly better fitting to the data than the PHT model. Moreover, a multi-group test of the TPB model demonstrated that the TPB model was invariant between the Japanese and the Korean samples.Originality/valueAlthough there had been an important question among job search literatures regarding how important the planned behavior in the job search processes would be, the study gave an empirical support to the TPB job search model in contrast to the PHT model. Another contribution is that the study tested the Western-driven theories using Asian samples from Japan and Korea, constituting an important benchmark for further studies that attempt to test the generalizability of the TPB model, particularly in countries/areas that employ different employment systems.

Bidirectional Relationships Between Parenting Processes and Deviance in a Sample of Inner-City African American Youth.

The current study assessed for bidirectional relationships among supportive parenting (knowledge), negative parenting (permissiveness), and deviance in a sample (N = 5,325) of poor, inner-city African American youth from the Mobile Youth Survey (MYS) over 4 years. Cross-lagged path analysis provided evidence of significant bidirectional paths among parenting processes (knowledge and permissiveness) and deviance over time. Follow-up multigroup tests provided only modest evidence of dissimilar relationships by sex and by developmental periods. The findings improve our understanding of developmental changes between parenting behaviors and deviance during adolescence and extended current research of the bidirectionality of parent and child relationships among inner-city African American youth.

Price fairness perceptions and hotel customers’ behavioral intentions

This study examines the causal relationship between consumers’ price fairness perceptions and behavioral intentions in the context of online hotel bookings. Using a cross-sectional sample of 506 customers of a budget hotel chain in the United Kingdom, structural equation modeling (using the partial least squares approach), multigroup t-test, and permutation tests were conducted to (1) validate the structural model where price fairness is the exogenous variable and behavioral intention is the endogenous variable and (2) examine whether the causal model is invariant (equivalent) across customers from different market segments—including, first-time and repeat customers, leisure, and business travelers. Results from the analysis supported a significant, direct relationship between customers’ perceptions of price fairness and behavioral intentions. The results of the multigroup test and permutation tests further indicated that first-time leisure customers are more sensitive to dynamic pricing practices and tend to perceive these practices as unfair. Thus, the budget hotel chain may want to be very cautious with new customers who are not familiar with this pricing practice.

Multigroup Testing for Items With Real-Valued Status Under Standard Arithmetic

This paper proposes a novel generalization of group testing, called multi-group testing, which relaxes the notion of "testing subset" in group testing to "testing multi-set". The generalization aims to learn more information of each item to be tested rather than identify only defectives as was done in conventional group testing. This paper provides efficient nonadaptive strategies for the multi-group testing problem. The major tool is a new structure, $q$-ary additive $(w,d)$-disjunct matrix, which is a generalization of the well-known binary disjunct matrix introduced by Kautz and Singleton in 1964.

Shyness and Unsociability and Their Relations With Adjustment in Chinese and Canadian Children

The goal of this study was to examine relations between different forms of social withdrawal (shyness, unsociability) and indexes of adjustment in Chinese and Canadian children. Participants were fourth- to eighth-grade students in urban China ( n = 787) and Canada ( n = 1,033). Data on social withdrawal and adjustment were obtained from multiple sources, including peer nominations, child self-reports, teacher ratings, and school records. Multigroup tests indicated that relations between shyness and adjustment did not differ in Chinese and Canadian children. However, relations between unsociability and adjustment variables were significantly different across the countries, with unsociability more strongly associated with adjustment difficulties in China than in Canada. Results are discussed in terms of historical and cultural backgrounds related to values of group orientation and individuality.

Multigroup Equivalence Analysis for High-Dimensional Expression Data.

Hypothesis tests of equivalence are typically known for their application in bioequivalence studies and acceptance sampling. Their application to gene expression data, in particular high-dimensional gene expression data, has only recently been studied. In this paper, we examine how two multigroup equivalence tests, the F-test and the range test, perform when applied to microarray expression data. We adapted these tests to a well-known equivalence criterion, the difference ratio. Our simulation results showed that both tests can achieve moderate power while controlling the type I error at nominal level for typical expression microarray studies with the benefit of easy-to-interpret equivalence limits. For the range of parameters simulated in this paper, the F-test is more powerful than the range test. However, for comparing three groups, their powers are similar. Finally, the two multigroup tests were applied to a prostate cancer microarray dataset to identify genes whose expression follows a prespecified trajectory across five prostate cancer stages.

Hirschi’s Reconceptualization of Self-Control: Is Truth Truly the Daughter of Time? Evidence from Eleven Cultures

PurposeThe conceptualization and measurement of self-control remains a debated topic, in criminology as well as other social and behavioral sciences. The current study compared the relationships between the Grasmick and colleagues (1993) self-control scale and the redefined self-control measure by Hirschi (2004) on measures of deviance in samples of adolescents. MethodsAnonymous, self-report data were collected from over N=16,000 middle and late adolescents in China, the Czech Republic, Hungary, Japan, the Netherlands, Slovenia, Spain, Switzerland, Taiwan, Turkey, and the United States. ResultsBased on latent constructs with items parcels in an SEM framework, multi-group tests were used to examine both the relative predictive utility of each self-control measure on deviance and the extent to which these relationships varied across cultures. Both scales appear to tap into self-control; however, findings provide evidence that the Grasmick et al. measure explains more variance. These links did not vary across cultural contexts. ConclusionsHirschi provocatively suggested that the truth is the daughter of time; yet, we find that the measure developed by Grasmick and colleagues, the most widely used scale, retains greater explanatory power, and does so in an invariant manner across all eleven developmental contexts examined.

Intragroup Socialization for Adult Korean Adoptees: A Multigroup Analysis

The purpose of the current study was to test a model of socialization among a sample of adult Korean adoptees. Based on the tenants of homophily and social identity theory, it was hypothesized that participants’ early racial and ethnic socialization experiences would account for their current intragroup friendships as adults, and that this relationship would be mediated by early intragroup contact and moderated by early ethnic identity status. The two ethnic and racial socialization variables (i.e., ethnic heritage activities and racial in-exposure) significantly accounted for participants’ relationships with other Korean adoptees and nonadopted Koreans, and the effects were partially explained by early intragroup contact. Results of multigroup testing indicated the proposed socialization model was non-invariant across groups, such that the effects of ethnic heritage activities on intragroup contact and the effect of racial in-exposure on friendships with Korean adoptees were significantly different based on early ethnic identity status.

Blessed are Those Who Wait: Validating the Filipino Version of the Academic Delay of Gratification Scale (ADOGS)

The objective of this study was to examine the psychometric properties of the Filipino version of the Aca- demic Delay of Gratification Scale (ADOGS; Bembenutty and Karabenick, Learn Individ Differ 10:329-346, 1998). This instrument measures the degree to which students postpone immediately available opportunities to satisfy their impulses in order to pursue important goals that are temporally remote but ostensibly more important. Filipino high school students (N = 425) completed the ADOGS. Both within-network and between-network approaches to construct validation were used. Responses to this questionnaire were shown to have good internal consistency reliability and support is provided for its construct validity in terms of its correlations with other theo- retically relevant educational constructs such as cognitive and metacognitive strategies. Multigroup tests showed strong invariance across year levels and partial invariance across genders. Implications for cross-cultural research are discussed.

Cyberbullying in context: Direct and indirect effects by low self-control across 25 European countries

Random samples of at least 1,000 youth, ages 9 to 16 years, from 25 European countries (N = 25,142) were used to test the salience of low self-control on cyberbullying perpetration and victimization (direct and indirect effects), framed by a cross-cultural developmental approach. Path models, which provided evidence of invariance by sex, tested the hypothesized links among low self-control as well as known correlates, including offline perpetration and victimization, and externalizing behaviours. Results showed positive associations between online and offline bullying behaviours (perpetration and victimization), and, more interestingly, both direct but mostly indirect effects by low self-control on cyberbullying perpetration and victimization; externalizing behaviours had little additional explanatory power. Importantly, multi-group tests by country samples provided evidence of quite modest differences in the tested links across the 25 developmental contexts, despite some observed differences in the amount of variance explained in the dependent measures.

P47phox Directs Murine Macrophage Cell Fate Decisions

Macrophage differentiation and function are pivotal for cell survival from infection and involve the processing of microenvironmental signals that determine macrophage cell fate decisions to establish appropriate inflammatory balance. NADPH oxidase 2 (Nox2)-deficient chronic granulomatous disease (CGD) mice that lack the gp91(phox) (gp91(phox-/-)) catalytic subunit show high mortality rates compared with wild-type mice when challenged by infection with Listeria monocytogenes (Lm), whereas p47(phox)-deficient (p47(phox-/-)) CGD mice show survival rates that are similar to those of wild-type mice. We demonstrate that such survival results from a skewed macrophage differentiation program in p47(phox-/-) mice that favors the production of higher levels of alternatively activated macrophages (AAMacs) compared with levels of either wild-type or gp91(phox-/-) mice. Furthermore, the adoptive transfer of AAMacs from p47(phox-/-) mice can rescue gp91(phox-/-) mice during primary Lm infection. Key features of the protective function provided by p47(phox-/-) AAMacs against Lm infection are enhanced production of IL-1α and killing of Lm. Molecular analysis of this process indicates that p47(phox-/-) macrophages are hyperresponsive to IL-4 and show higher Stat6 phosphorylation levels and signaling coupled to downstream activation of AAMac transcripts in response to IL-4 stimulation. Notably, restoring p47(phox) protein expression levels reverts the p47(phox)-dependent AAMac phenotype. Our results indicate that p47(phox) is a previously unrecognized regulator for IL-4 signaling pathways that are important for macrophage cell fate choice.

Exploring attitudes towards computer use among pre-service teachers from Singapore and the United Kingdom: A multi-group invariance test of the Technology Acceptance Model (TAM)

Exploring attitudes towards computer use among pre-service teachers from Singapore and the United Kingdom: A multi-group invariance test of the Technology Acceptance Model (TAM)

Un instrument de mesure des pratiques éducatives parentales à l’adolescence : validation auprès d’adolescents du Québec et de France

This article reports the intercultural validation of a measuring instrument of parental practices. Participants are 722 adolescents (439 Quebecers and 283 French) aged between 11 and 17, with a mean age of 15.57 years. The instrument comprises six scales measuring adolescents’ perception of the parental practices of their mother and father: emotional closeness, parental rejection, parental tolerance towards peers, communication, control, and disciplinary styles of parents. The scales’ internal consistency is adequate. Confirmatory factor analyses (multigroup tests) indicate a satisfying factorial invariability, across the two cultures, for the vast majority of the 11 factors structuring the six scales of parental practices. This instrument is thus recommendable for developmental research with adolescents from Quebec and France.

Maternal behaviors and restrained eating and body dissatisfaction in young children

The present study aimed at testing the relations between maternal weight concern and maternal encouragement to be thin as perceived by the child, and restraint and body dissatisfaction in young children. Cross-sectional data were collected among 501 children (aged 7-10), using self-reports on maternal behaviors, body dissatisfaction, and restraint. Height and weight were objectively measured. Model testing was conducted with M+, and multigroup tests were conducted to test differences between the sexes, and between younger and older children. Associations between the child's perception of maternal encouragement to be thin and child body dissatisfaction and restrained eating were found, whereas the child's perception of maternal weight concern was primarily related to child restrained eating. No sex differences were found, but the relations were stronger for the older children. Not only in girls, but in boys as well the child's perception of maternal behaviors plays a role. At primary school age children may become more vulnerable to possible maternal influences.

Motivation and Engagement in Music and Sport: Testing a Multidimensional Framework in Diverse Performance Settings

The present study assessed the application of a multidimensional model of motivation and engagement (the Motivation and Engagement Wheel) and its accompanying instrumentation (the Motivation and Engagement Scale) to the music and sport domains. Participants were 463 young classical musicians (N=224) and sportspeople (N=239). In both music and sport samples, the data confirmed the good fit of the four hypothesized higher-order dimensions and their 11 first-order dimensions: adaptive cognitions (self-efficacy, valuing, mastery orientation), adaptive behaviors (planning, task management, persistence), impeding/maladaptive cognitions (uncertain control, anxiety, failure avoidance), and maladaptive behaviors (self-handicapping, disengagement). Multigroup tests of factor invariance showed that in terms of underlying motivational constructs and the composition of and relationships among these constructs, key subsamples are not substantially different. Moreover-and of particular relevance to issues around the generalizability of the framework-the factor structure for music and sport samples was predominantly invariant.

A multigroup diffusion solver using pseudo transient continuation for a radiation-hydrodynamic code with patch-based AMR

We present a scheme to solve the nonlinear multigroup radiation diffusion (MGD) equations. The method is incorporated into a massively parallel, multidimensional, Eulerian radiation-hydrodynamic code with Adaptive Mesh Refinement (AMR). The patch-based AMR algorithm refines in both space and time creating a hierarchy of levels, coarsest to finest. The physics modules are time-advanced using operator splitting. On each level, separate “level-solve” packages advance the modules. Our multigroup level-solve adapts an implicit procedure which leads to a two-step iterative scheme that alternates between elliptic solves for each group with intra-cell group coupling. For robustness, we introduce pseudo transient continuation (Ψtc). We analyze the magnitude of the Ψtc parameter to ensure positivity of the resulting linear system, diagonal dominance and convergence of the two-step scheme. For AMR, a level defines a subdomain for refinement. For diffusive processes such as MGD, the refined level uses Dirichlet boundary data at the coarse–fine interface and the data is derived from the coarse level solution. After advancing on the fine level, an additional procedure, the sync-solve (SS), is required in order to enforce conservation. The MGD SS reduces to an elliptic solve on a combined grid for a system of G equations, where G is the number of groups. We adapt the “partial temperature” scheme for the SS; hence, we reuse the infrastructure developed for scalar equations. Results are presented. We consider a multigroup test problem with a known analytic solution. We demonstrate utility of Ψtc by running with increasingly larger timesteps. Lastly, we simulate the sudden release of energy Y inside an Al sphere (r=15cm) suspended in air at STP. For Y=11kT, we find that gray radiation diffusion and MGD produce similar results. However, if Y=1MT, the two packages yield different results. Our large Y simulation contradicts a long-standing theory and demonstrates the inadequacy of gray diffusion.