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Complexity Levels (complexity + level)

Distribution by Scientific Domains

Psychology	57%

Selected Abstracts

Blind decoder-assisted interference reduction for coded DS-CDMA systems,

INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 9 2005
Ryan A. Pacheco
Abstract We propose an iterative blind interference reduction strategy for short-burst coded DS-CDMA systems. The blind strategy works by creating a set of ,training sequences' in the receiver that are used as input to an interference reduction algorithm whose task is to produce a corresponding set of equalizers that attempt to recover the desired signal. To maintain a reasonable complexity level we develop a semi-blind interference reduction algorithm that is capable of equalizing the received signal with a relatively small training sequence length (thus maintaining a small training sequence set). The objective then becomes to determine which equalizer from the generated set gives the best performance (smallest bit error). It is demonstrated that the success of this scheme depends greatly on the ability to find an appropriate criterion for picking the best equalizer. Of the tested criteria, one based on feedback from the decoder (essentially using trellis information) is shown to achieve nearly optimal performance. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Assessment of sensory substitution prosthesis potentialities in minimalist conditions of learning

APPLIED COGNITIVE PSYCHOLOGY, Issue 4 2006
Colline Poirier
Pattern recognition with a prosthesis substituting vision by audition was investigated. During 15 1-hour sessions, nine blindfolded sighted subjects were trained to recognise 2D patterns by trial and error. In addition to a global assessment, recognition of pattern element nature (vertical bars, horizontal bars,), element size and element spatial arrangement were independently assessed for each pattern. Influence of experimental parameters (complexity level of patterns, exploration number of a pattern) on recognition was studied. Performances improved over sessions. As a rule, patterns element nature was less well recognised than element size and spatial arrangement. Experimental parameters influenced pattern recognition performance. Results are discussed in relation with auditory and visual perception as well as in the perspective to implement a learning protocol for future users of prosthesis. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Validity of General Mental Ability for the Prediction of Job Performance and Training Success in Germany: A meta-analysis1

INTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 1 2007
Ute R. Hülsheger
A meta-analysis into the operational validity of general mental ability (GMA) measures in Germany is presented. The meta-analysis addresses the question whether findings of US and European meta-analyses are generalizable to Germany given the differences in the education systems of these countries. The high level of differentiation in the German educational system is expected to enhance the homogeneity of applicant pools resulting in a low level of variability in predictor scores which reduces the observed GMA,performance relationships. Our analysis is based on 54 independent German articles and unpublished reports. Results indicated an operational validity of ,=.467 for training success (k=90; N=11,969) and ,=.534 for job performance (k=9; N=746). Moderator analyses showed that job complexity and the year of publication are relevant moderator variables, with lower job complexity levels and older studies being associated with higher operational validities. Findings suggest that overall German operational validities are comparable with findings in the United States or other European countries. However, for training success operational GMA validities are slightly lower in Germany compared with US or European meta-analyses. [source]

Integrative Complexity of 41 U.S. Presidents

POLITICAL PSYCHOLOGY, Issue 2 2007
Felix J. Thoemmes
Although U.S. presidents are one of the most studied groups of political figures and integrative complexity is one of the most widely used constructs in political psychology, no study to date has fully examined the integrative complexity of all U.S. presidents. The present study helps fill in that gap by scoring 41 U.S. presidents' first four State of the Union speeches for integrative complexity and then comparing these scores with a large range of available situational and personality variables. Results suggest a tendency for presidents' integrative complexity to be higher at the beginning of their first term and drop at the end. This pattern was pronounced for presidents who eventually won reelection to a second term and was markedly different for presidents who tried to gain reelection but lost. Additional analyses suggested that presidents' overall integrative complexity scores were in part accounted for by chronic differences between presidents' complexity levels. Further analyses revealed that this overall integrative complexity score was positively correlated to a set of interpersonal traits (friendliness, affiliation motive, extraversion, and wittiness) and negatively correlated with inflexibility. Discussion centers upon the causes and consequences of presidential complexity. [source]

Theory of Mind and Relational Complexity

CHILD DEVELOPMENT, Issue 5 2003
Glenda Andrews
Cognitive complexity and control theory and relational complexity theory attribute developmental changes in theory of mind (TOM) to complexity. In 3 studies, 3-, 4-, and 5-year-olds performed TOM tasks (false belief, appearance,reality), less complex connections (Level 1 perspective-taking) tasks, and transformations tasks (understanding the effects of location changes and colored filters) with content similar to TOM. There were also predictor tasks at binary-relational and ternary-relational complexity levels, with different content. Consistent with complexity theories: (a) connections and transformations were easier and mastered earlier than TOM; (b) predictor tasks accounted for more than 80% of age-related variance in TOM; and (c) ternary-relational items accounted for TOM variance, before and after controlling for age and binary-relational items. Prediction did not require hierarchically structured predictor tasks. [source]

Varieties of sameness: the impact of relational complexity on perceptual comparisons,

COGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 3 2004
James K. Kroger
Abstract The fundamental relations that underlie cognitive comparisons,"same" and "different",can be defined at multiple levels of abstraction, which vary in relational complexity. We compared response times to decide whether or not two sequentially-presented patterns, each composed of two pairs of colored squares, were the same at three levels of abstraction: perceptual, relational, and system (higher order relations). For both 150 ms and 5 s inter-stimulus intervals (ISIs), both with and without a masking stimulus, decision time increased with level of abstraction. Sameness at lower complexity levels contributed to decisions based on the higher levels. The pattern of comparison times across levelswas not predictable solely from encoding times. The results indicated that relations at multiple levels of complexity can be abstracted and compared in working memory, with higher complexity levels requiring more processing time. We simulated the impact of relational complexity on response time using Learning and Inference with Schemas and Analogies (LISA), a computational model of relational comparisons based on dynamic binding of elements into roles in a relational working memory. [source]