Determining the optimal decision delay parameter for a linear equalizer

The achievable bit error rate of a linear equalizer is crucially determined by the choice of a decision delay parameter. This brief paper presents a simple method for the efficient determination of the optimal decision delay parameter that results in the best bit error rate performance for a linear equaliz

Concurrent constant modulus algorithm and soft decision directed scheme for fractionally-spaced blind equalization

The paper proposes a concurrent constant modulus algorithm (CMA) and soft decision-directed (SDD) scheme for low-complexity blind equalization of high-order quadrature amplitude modulation channels. Simulation using a fractionally-spaced equalization setting is used to compare the proposed scheme with the recently introduced state-of-art concurrent CMA and decision-directed (DD) scheme. The proposed CMA+SDD blind equalizer is shown to have simpler computational complexity per weight update, faster convergence speed, and slightly improved steady-state equalization performance, compared with the CMA+DD blind equalizer

Commuting and wellbeing in London: The roles of commute mode and local public transport connectivity.

PublishedJournal ArticleOBJECTIVES: To explore the relationships between commute mode, neighbourhood public transport connectivity and subjective wellbeing. METHOD: The study used data on 3630 commuters in London from wave two of Understanding Society (2010/11). Multivariate linear regressions were used to investigate how commute mode and neighbourhood public transport connectivity were associated with subjective wellbeing for all London commuters and for public transport commuters only. Subjective wellbeing was operationalized in terms of both a positive expression (life satisfaction measured by a global single-item question) and a more negative expression (mental distress measured by the General Health Questionnaire). Logistic regression was also used to explore the predictors of public transport over non-public transport commutes. RESULTS: After accounting for potentially-confounding area-level and individual-level socioeconomic and commute-related variables, only walking commutes (but not other modes) were associated with significantly higher life satisfaction than car use but not with lower mental distress, compared to driving. While better public transport connectivity was associated with significantly lower mental distress in general, train users with better connectivity had higher levels of mental distress. Moreover, connectivity was unrelated to likelihood of using public transport for commuting. Instead, public transport commutes were more likely amongst younger commuters who made longer distance commutes and had comparatively fewer children and cars within the household. CONCLUSION: The findings highlight the heterogeneity of relationships between commute mode, public transport connectivity and subjective wellbeing and have implications for intervention strategies and policies designed to promote commuting behaviour change.This work was undertaken as part of the first author's PhD funded by a Shell Global Solutions (UK) award to CA and supervised by CA, MW and SS. CA is partially funded by UK National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care of the South West Peninsula PenCLAHRC. MW is partially funded by NIHR Health Protection Research Unit in Environmental Change and Health at the London School of Hygiene and Tropical Medicine in partnership with Public Health England (PHE), and in collaboration with the University of Exeter, University College London, and the Met Office. The views expressed are those of the authors and not necessarily those of Shell Global Solutions (UK), the NHS or the NIHR, the Department of Health or PHE. The authorship order reflects relative contribution

DENT-DDSP: Data-efficient noisy speech generator using differentiable digital signal processors for explicit distortion modelling and noise-robust speech recognition

The performances of automatic speech recognition (ASR) systems degrade drastically under noisy conditions. Explicit distortion modelling (EDM), as a feature compensation step, is able to enhance ASR systems under such conditions by simulating the in-domain noisy speeches from the clean counterparts. Yet, existing distortion models are either non-trainable or unexplainable and often lack controllability and generalization ability. In this paper, we propose a fully explainable and controllable model: DENT-DDSP to achieve EDM. DENT-DDSP utilizes novel differentiable digital signal processing (DDSP) components and requires only 10 seconds of training data to achieve high fidelity. The experiment shows that the simulated noisy data from DENT-DDSP achieves the highest simulation fidelity compared to other baseline models in terms of multi-scale spectral loss (MSSL). Moreover, to validate whether the data simulated by DENT-DDSP are able to replace the scarce in-domain noisy data in the noise-robust ASR tasks, several downstream ASR models with the same architecture are trained using the simulated data and the real data. The experiment shows that the model trained with the simulated noisy data from DENT-DDSP achieves similar performances to the benchmark with a 2.7\% difference in terms of word error rate (WER). The code of the model is released online

Unequal Intra-layer Coupling in a Bilayer Driven Lattice Gas

The system under study is a twin-layered square lattice gas at half-filling, being driven to non-equilibrium steady states by a large, finite `electric' field. By making intra-layer couplings unequal we were able to extend the phase diagram obtained by Hill, Zia and Schmittmann (1996) and found that the tri-critical point, which separates the phase regions of the stripped (S) phase (stable at positive interlayer interactions J_3), the filled-empty (FE) phase (stable at negative J_3) and disorder (D), is shifted even further into the negative J_3 region as the coupling traverse to the driving field increases. Many transient phases to the S phase at the S-FE boundary were found to be long-lived. We also attempted to test whether the universality class of D-FE transitions under a drive is still Ising. Simulation results suggest a value of 1.75 for the exponent gamma but a value close to 2.0 for the ratio gamma/nu. We speculate that the D-FE second order transition is different from Ising near criticality, where observed first-order-like transitions between FE and its "local minimum" cousin occur during each simulation run.Comment: 29 pages, 19 figure

Design of an Improved Heater Array to Measure Microscale Wall Heat Transfer

An improved array of microscale heaters is being developed to measure the heat transfer coefficient at many points underneath individual bubbles during boiling as a function of space and time. This heater array enables the local heat transfer from a surface during the bubble growth and departure process to be measured with very high temporal and spatial resolution, and should allow better understanding of the boiling heat transfer mechanisms by pin-pointing when and where in the bubble departure cycle large amounts of wall heat transfer occur. Such information can provide much needed data regarding the important heat transfer mechanisms during the bubble departure cycle, and can serve as benchmarks to validate many of the analytical and numerical models used to simulate boiling. The improvements to the heater array include using a silicon-on-quartz substrate to reduce thermal cross-talk between the heaters, decreased space between the heaters, increased pad sizes on the heaters, and progressive heater sizes. Some results using the present heater array are discussed

The role of strengths in anger and conduct problems in maltreated adolescents

Despite multi-type maltreatment, some individuals demonstrate positive adaptation and continue to develop in a healthy way. A multitude of strength factors have been linked to adaptive functioning and resilience, but this has not been adequately examined in maltreated adolescent’s psychosocial functioning. This study sought to examine the role of strengths such as having talents/interests, family relationships, educational support, the role of the recognition and application of these strengths, and the role of multi-type maltreatment on anger control and conduct problems. One hundred and thirty participants (61 males; 69 females) aged 13–19 years old were rated using the Singapore version of Child and Adolescent Needs and Strengths (CANS) tool. The results revealed that certain strengths were associated with anger and conduct problems, but the recognition and application of strengths emerged as a consistently significant predictor for both outcomes. Hence, to understand and apply one’s strengths may be equally as important as merely possessing those strengths. This study extends current understanding of the importance of strengths with a group of maltreated adolescents in an Asian context. Adopting a person-centered and strength-based approach will further enhance the effectiveness of interventions and improve outcomes for maltreated adolescents living in residential care

Consideration of environmental factors in reflections on car purchases: Attitudinal, behavioural and sociodemographic predictors among a large UK sample

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record Encouraging the purchase of low-emission vehicles could reduce the environmental impact of growing global car ownership. To date, however, there is relatively little research into the degree to which environmental features, such as reduced CO2 emissions, are considered important when reflecting on car purchase decisions using large representative samples. This issue was explored using data from wave four (2013/14) of the UK Household Longitudinal Study, weighted to be representative of the UK population (N = 12,895). Principal components analysis identified three types of considerations during car purchase reflections: Utilitarian, Image-conscious and Environmental. Logistic and Ordinary Least Squares regressions identified attitudinal, behavioural and sociodemographic predictors of reporting environmental considerations during car purchase. Consideration of environmental factors during reflections on car purchases was more likely among those with higher climate change concerns and topic engagement, as well as self-reported pro-environmental behaviours more generally. Environmental considerations were also higher amongst women, older adults, non-white ethnic groups, urban residents and among individuals in Scotland (vs. London). Contrary to previous findings, richer and more educated respondents were less likely to consider environmental factors, with income positively related to image factors such as brand. Although our findings offer some support for the pro-environmental attitude–behaviour consistency hypothesis, they also highlight key non-attitudinal, sociodemographic factors underlying car purchase reflections that may help social-marketers and policy makers identify key audiences to more effectively promote low-emission vehicle purchases.Shell Global Solutions(NIHR) Collaboration for Leadership in Applied Health Research and Care of the South West Peninsula PenCLAHRCNIHR Health Protection Research Unit in Environmental Change and Health at the London School of Hygiene and Tropical Medicine in partnership with Public Health Englan