Impact of Statistical Multiplexing on Voice Quality in Cellular Networks

This paper examines the quality of transmission of voice over cellular, packet-switched networks. The medium access mechanism in the uplink is simulated under various statistical multiplexing scenarios in order to assess the effect of front-end clipping on voice quality. Moreover, the simulation is implemented in a real-time demonstration platform utilized to acquire subjective indicators of voice quality by performing Mean Opinion Score (MOS) tests. Results from the MOS tests are reported, and an analysis of the obtained speech samples is presented. Finally, the results are summarized and potential further directions for the simulation tool and the speech models are discussed.     

Relearning face-name associations in early Alzheimer's disease.

Preliminary evidence for the effectiveness of cognitive rehabilitation interventions based on errorless learning principles in early-stage Alzheimer's disease (AD) was provided by Clare et al. (1999, 2000, 2001). The present study extends these findings in a controlled trial. Twelve participants meeting criteria for probable AD, with Mini-Mental State Examination scores of 18 or above, were trained in face-name associations using an effortless learning paradigm. Training produced a significant group improvement in recall of trained, but not control, items. Gains were largely maintained 6 months later, in the absence of practice. There were differences in individual response to intervention. Results did not differ according to medication status, and the intervention had no adverse effects on self-reported well-being, but participants who were more aware of their memory difficulties achieved better outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological functioning in posttraumatic stress disorder and alcohol abuse.

Studies have shown differences in neuropsychological functioning between groups with posttraumatic stress disorder (PTSD) and control participants. Because individuals with PTSD often have a history of comorbid alcohol abuse, the extent to which an alcohol confound is responsible for these differences remains a concern. The current study compares neuropsychological testing scores in 4 groups of veterans with and without PTSD (PTSD+ and PTSD-, respectively) and with and without a history of alcohol abuse (ETOH+ and ETOH-, respectively): n for PTSD+/ETOH- = 30, n for PTSD+/ETOH- = 37, n for PTSD-/ETOH+ = 30, and n for PTSD-/ETOH- = 31. Results showed that PTSD, when alcohol, educational level, vocabulary, and depression are controlled for, was associated with decreased verbal memory, attention, and processing speed performance. Alcohol abuse history was associated with decreased visual memory performance. By controlling for alcohol and depression, the authors can more conclusively demonstrate that verbal memory and attention differences are associated with PTSD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of a matrix converter to enhance the sensorless control of a surface-mount permanent-magnet AC motor at zero and low frequency

This paper addresses the use of a matrix converter (MC) with high-frequency voltage injection for zero- and low-speed sensorless control of surface mount permanent magnet alternating current motors. This paper also proposes a dual compensation technique that can practically eliminate zero-current-crossing distortions in MCs, discusses the effect of such distortions on sensorless control using injection techniques, and presents experimental results that illustrate the enhanced low-speed sensorless performance that can be obtained from exploiting the effective linearity of the MC operation.     

Narratives of Spatial Division： The Role of Social Memory in Shaping Urban Space in Belfast

The paper examines the role of shared spaces in divided cities in promoting future sustainable communities and spaces described as inclusive to all. It addresses the current challenges that prevent such inclusiveness and suggests future trends of its development to be of benefit to the wider city community. It explains how spaces in divided cities are carved up into perceived ownerships and territorialized areas, which increases tension on the shared space between territories; the control of which can often lead to inter-community disputes. The paper reports that common shared space in-between conflicting communities takes on increased importance since the nature of the conflict places emphasis on communities＇ confidence, politically and socially, while also highlighting the necessity for confidence in inclusion and feeling secure in the public domain. In order to achieve sustainable environments, strategies to promote shared spaces require further focus on the significance of everyday dynamics as essential aspects for future integration and conflict resolution.     

双向IGBT开关在矩阵变换器中的应用

双向IGBT模块是实现高频矩阵变换器极为有效的方法。略不同于硬开关PWM变换器，矩阵变换器中的开关和传导损耗取决于所选的调制策略。本文介绍了一种由诺丁汉大学推导的平均损耗的计算公式。测试一个使用1200V，200A的双向模块实现的三相到单相的构造，得到的波形说明了矩阵变换器的实际操作以及可能会出现的输出电流纹波。     

Calculation of Viscous EHL Traction for Squalane Using Molecular Simulation and Rheometry

Recently, remarkable agreement was reported between nonequilibrium molecular dynamics simulation and high-pressure Couette rheometry on squalane. We have utilized the viscosity-strain rate relationship obtained from this unique combination of experimental and simulation data along with high-pressure viscometer measurements to calculate the viscous traction curve in the elastohydrodynamic lubrication (EHL) regime. A comparison with measured traction at 0.57 and 1.29 GPa shows excellent agreement, confirming the validity of the measurements and simulations. Thus, we present for the first time, a successful calculation of EHL traction from the liquid shear response obtained from both molecular dynamics and rheometry.     

Sibling conflict in middle childhood predicts children's adjustment in early adolescence.

Associations between sibling conflict in middle childhood and psychological adjustment in early adolescence were studied in a sample of 80 boys and 56 girls. Parents and children provided self-report data about family relationships and children's adjustment. Parents' hostility to children was assessed from videotaped interactions. Results showed that sibling conflict at Time 1 predicted increases in children's anxiety, depressed mood, and delinquent behavior 2 years later. Moreover, earlier sibling conflict at Time 1 accounted for unique variance in young adolescents' Time 2 anxiety, depressed mood, and delinquent behavior above and beyond the variance explained by earlier maternal hostility and marital conflict. Children's adjustment at Time 1 did not predict sibling conflict at Time 2. Results highlight the unique significance of the earlier sibling relationship for young adolescents' psychological adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The examination of myofascial face pain and its relationship to psychological distress among women.

In this study, 110 female myofascial face pain patients were assessed monthly for 10 months on measures of pain, distress, and stressful life events. D. A. Kenny and A. J. Zautra's (1995) structural equation model for examining the separate trait, state, and error components of the variables was used to analyze the data. Both pain and distress had sizable trait variance, and the trait components were correlated. The 2 variables also showed sizable state variance, and the states of pain covaried with states of distress. A significant time-lagged relationship between the 2 variables was found: Increases in distress led to elevations in pain 1 mo later. Stressful life events arising from major social roles were also associated with greater distress, but not pain. Illness events unrelated to the pain syndrome were associated with both pain and distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)