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51.
Michael Bale Brady Laska Dustin Dunwell Francois Chan Hamid Jafarkhani 《Wireless Communications, IEEE Transactions on》2007,6(2):463-467
Super-orthogonal space-time trellis codes (SOSTTCs) designed by hand can significantly improve the performance of space-time trellis codes. This paper introduces a new representation of SOSTTCs based on a generator matrix that allows a systematic and exhaustive search of all possible codes. This will verify that some of the known codes are optimal, and provides a means to easily implement encoders and decoders with a large number of states without relying on a graphical representation. New codes with up to 256 states that outperform previously known codes are presented 相似文献
52.
Bin Lee Cioffi J.M. Jagannathan S. Kibeom Seong Youngjae Kim Mohseni M. Brady M.H. 《Communications, IEEE Transactions on》2007,55(8):1617-1628
This paper introduces a multiple-input multiple-output channel model for the characterization of a binder of telephone lines. This model is based on multiconductor transmission line theory, and uses parameters that can be obtained from electromagnetic theory or measured data. The model generates frequency-dependent channel/binder transfer function matrices as a function of cable type, geometric line-spacing and twist-length parameters, and source--load configurations. The model allows the extraction of the magnitude and the phase of individual near end crosstalk, far end crosstalk, split-pair, and phantom transfer functions from the transfer function matrix of the binder. These individual crosstalk transfer functions are often found to be very sensitive to small imperfections in the binder. Examples of category 3 twisted pair American telephone lines and ldquoquadrdquo telephone cables are also presented. 相似文献
53.
Fabric woven from wool/polyester (PES) Murata vortex spun (MVS) blend yarn is a commercially viable proposition particularly on the basis of advantageous wear-resistant properties, compared with fabric made from traditional worsted ring-spun yarn. However, in some early industrial trials with fabric made from 45/55-blend wool/PES MVS yarn, significantly greater relaxation shrinkage was found relative to comparable worsted ring-spun fabric. It was noted at the time that the amount of relaxation shrinkage in MVS fabric could be reduced to a large extent by using steamed MVS yarn. In this study, the extent of variations in the dimensional and mechanical properties of fabric samples woven from a combination of steamed and unsteamed MVS yarn and equivalent worsted ring-spun yarn is examined. In general, greater hygral expansion and relaxation shrinkage were found in loom-state fabrics made from unsteamed MVS yarns, whereas the fabric made from steamed MVS and ring-spun yarns gave relatively low levels of relaxation shrinkage and hygral expansion. Permanent setting of fabrics, by pressure steaming, was found to be more effective than yarn pre-steaming in reducing relaxation shrinkage levels of fabrics made from unsteamed MVS yarn. After pressure steaming, all fabrics showed similar levels of relaxation shrinkage and hygral expansion. Permanent setting of the fabrics, by pressure steaming, resulted in similar levels of relaxation shrinkage and hygral expansion, irrespective of the yarn production method; relaxation shrinkage fell to around 1% and hygral expansion increased by about 1%, relative to the loom-state samples. MVS fabrics were relatively heavier and fuller and had a firmer handle than the worsted ring-spun fabrics, reflecting the greater fabric weight, thickness and shear rigidity measured on these fabrics. These attributes are associated with different structures of the worsted ring-spun and MVS yarns used to make the fabrics. 相似文献
54.
Casas J. Manuel; Brady Stephen; Ponterotto Joseph G. 《Canadian Metallurgical Quarterly》1983,30(2):139
Used an illusory correlation paradigm to measure the effect of stereotyping by mental health professionals on processing information about individuals identified according to sex and sexual preference (SP). 34 23–58 yr old mental health professionals (17 males and 17 females) rated themselves on an SP scale, were presented a series of cards that identified hypothetical persons according to sex and SP, and ascribed to these persons 2 randomly selected stereotypic characteristics associated with 1 of the SP groups. After studying the cards, Ss were asked to make judgments about the relationship between SP and sex and the stereotypic characteristics. Fewer errors were made on those items for which a stereotypic response was congruent with prevailing stereotypes than on those items for which the stereotypic response was incongruent, indicating that stereotyping did affect the processing of information relative to the sex and SP group. Ss had more difficulty correctly processing information attributed to gay men and lesbian women than information attributed to heterosexual men and women. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Centerbar David B.; Schnall Simone; Clore Gerald L.; Garvin Erika D. 《Canadian Metallurgical Quarterly》2008,94(4):560
In five studies, the authors examined the effects on cognitive performance of coherence and incoherence between conceptual and experiential sources of affective information. The studies crossed the priming of happy and sad concepts with affective experiences. In different experiments, these included approach or avoidance actions, happy or sad feelings, and happy or sad expressive behaviors. In all studies, coherence between affective concepts and affective experiences led to better recall of a story than did affective incoherence. The authors suggest that the experience of such experiential affective cues serves as evidence of the appropriateness of affective concepts that come to mind. The results suggest that affective coherence has epistemic benefits and that incoherence is costly in terms of cognitive performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Anxiety levels in a sample of 65 long-term cancer survivors were assessed in a study of the effects of a planned discharge from an oncology clinic. Thirty-one percent of patients scored > or = 8, and 12% > or = 11 on the anxiety subscale of the Hospital Anxiety and Depression Scale (HADS), indicating that anxiety rates in patients in long-standing remission do not greatly differ from patients with active disease. Despite the provision of continued support and guaranteed fast-access return to the clinic if necessary, 28% of patients refused to be discharged. Fear that recurrence would not be detected was the reason most frequently cited. Seventy-five percent of these patients were HADS anxiety cases. A second assessment 4-5 months later of the 41 patients who were discharged showed a slight, but non-significant increase in anxiety rates suggesting that anxiety in cancer survivors may be persistent and not related to clinic attendance. 相似文献