1,040 research outputs found
Studies on noise robust automatic speech recognition
Noise in everyday acoustic environments such as cars, traffic environments, and cafeterias remains one of the main challenges in automatic speech recognition (ASR). As a research theme, it has received wide attention in conferences and scientific journals focused on speech technology. This article collection reviews both the classic and novel approaches suggested for noise robust ASR. The articles are literature reviews written for the spring 2009 seminar course on noise robust automatic speech recognition (course code T-61.6060) held at TKK
Mapping Transient Hyperventilation Induced Alterations with Estimates of the Multi-Scale Dynamics of BOLD Signal
Temporal blood oxygen level dependent (BOLD) contrast signals in functional MRI during rest may be characterized by power spectral distribution (PSD) trends of the form 1/fα. Trends with 1/f characteristics comprise fractal properties with repeating oscillation patterns in multiple time scales. Estimates of the fractal properties enable the quantification of phenomena that may otherwise be difficult to measure, such as transient, non-linear changes. In this study it was hypothesized that the fractal metrics of 1/f BOLD signal trends can map changes related to dynamic, multi-scale alterations in cerebral blood flow (CBF) after a transient hyperventilation challenge. Twenty-three normal adults were imaged in a resting-state before and after hyperventilation. Different variables (1/f trend constant α, fractal dimension Df, and, Hurst exponent H) characterizing the trends were measured from BOLD signals. The results show that fractal metrics of the BOLD signal follow the fractional Gaussian noise model, even during the dynamic CBF change that follows hyperventilation. The most dominant effect on the fractal metrics was detected in grey matter, in line with previous hyperventilation vaso-reactivity studies. The α was able to differentiate also blood vessels from grey matter changes. Df was most sensitive to grey matter. H correlated with default mode network areas before hyperventilation but this pattern vanished after hyperventilation due to a global increase in H. In the future, resting-state fMRI combined with fractal metrics of the BOLD signal may be used for analyzing multi-scale alterations of cerebral blood flow
Measurements of muon flux in the Pyh\"asalmi underground laboratory
The cosmic-ray induced muon flux was measured at several depths in the
Pyh\"asalmi mine (Finland) using a plastic scintillator telescope mounted on a
trailer. The flux was determined at four different depths underground at 400 m
(980 m.w.e), at 660 m (1900 m.w.e), at 990 m (2810 m.w.e) and at 1390 m (3960
m.w.e) with the trailer, and also at the ground surface. In addition,
previously measured fluxes from depths of 90 m (210 m.w.e) and 210 m (420
m.w.e) are shown. A relation was obtained for the underground muon flux as a
function of the depth. The measured flux follows well the general behaviour and
is consistent with results determined in other underground laboratories.Comment: 8 pages, 2 figures. Submitted to Nuclear Instrum. Methods
The effect of low childhood income on self-harm in young adulthood : Mediation by adolescent mental health, behavioural factors and school performance
Low childhood income is an established risk factor of self-harm in adolescence and young adulthood, and childhood income is additionally associated with various correlates of self-harm. How these correlates, such as psychiatric disorders, substance abuse, violent behaviour and school problems, mediate the effect of childhood income on self-harm, is less understood. The purpose of the current paper is to examine this mediation. The study is based on administrative register data on all Finnish children born in 1990-1995. An analytical sample of 384,121 children is followed from age 8 to 22. We apply the parametric g-formula to study the effect of childhood income on the risk of self-harm in young adulthood. Adolescent psychiatric disorders, substance abuse, prior self-harm, violent criminality and victimization, out-of-home placements, not being in education, employment or training and school performance are considered as potential mediators. We control for confounding factors related to childhood family characteristics. As a hypothetical intervention, we moved those in the lowest childhood income quintile to the second-lowest quintile, which resulted in a 7% reduction in hospital-presenting self-harm in young adulthood among those targeted by the intervention (2% reduction in the total population). 67% of the effect was mediated through the chosen mediators. The results indicate that increases in childhood material resources could protect from self-harm in young adulthood. Moreover, the large proportion of mediation suggests that targeted interventions for high-risk adolescents may be beneficial. To our knowledge, this is the first paper to use the parametric g-formula to study youth self-harm. Future applications are encouraged as the method offers several further opportunities for analysing the complex life course pathways to self-harm.Peer reviewe
Effectiveness of a workshop-based intervention to reduce bullying and violence at work: A 2-year quasi-experimental intervention study
INTRODUCTION: Bullying and violence at work are associated with reduced wellbeing of the victims, but few evidence-based interventions are available to prevent these offensive behaviours. We developed and examined the effectiveness of an intervention aimed at prevention of bullying and violence at work through modifications in psychosocial work environment. METHODS: In accordance with pre-published protocol, employees and supervisors of 12 work units in 3 cities (intervention group A: n = 315; intervention group B: n = 271) received a workshop-based intervention on organizational practices to prevent bullying and violence, including supervisor support, supervisor justice, workplace social capital, and psychological safety and were compared to a reference group (n = 2310) which did not receive the intervention. Latent change score modelling (LCSM) was used to estimate between- and within-individual differences in changes of organizational practices and prevalence of bullying and violence from baseline (2020) to follow-up (2022). RESULTS: No direct or indirect effects of intervention were observed. Of the potential mediator variables, supervisor support (B = 0.04; 95% confidence interval 0.006, 0.07) and supervisor justice (0.04; 0.01, 0.08) improved in the intervention group B between the measurements and compared to control group, but the result was not replicated in intervention group A. No changes were observed between the measurement points in bullying or violence at work. CONCLUSIONS: No intervention effects on bullying and violence at work were observed. It may be worthwhile to develop the intervention further to focus more on supervisor and co-worker relationships and on psychosocial resources of work team
Unified incremental nonlinear controller for the transition control of a hybrid dual-axis tilting rotor quad-plane
Overactuated Tilt Rotor Unmanned Aerial Vehicles are renowned for exceptional
wind resistance and a broad operational range, which poses complex control
challenges due to non-affine dynamics. Traditional solutions employ multi-state
switched logic controllers for transitions. Our study introduces a novel
unified incremental nonlinear controller for overactuated dual-axis tilting
rotor quad-planes, seamlessly managing pitch, roll, and physical actuator
commands. The control allocation problem is addressed using a SQP iterative
optimization algorithm, well-suited for nonlinear actuator effectiveness in
thrust vectoring vehicles. The controller design integrates desired roll and
pitch angle inputs. These desired attitude angles are autonomously managed by
the controller and then conveyed to the vehicle during slow airspeed phases,
when the vehicle maintains its 6 DOF. We incorporate an AoA protection logic to
prevent wing stall and a yaw rate reference model for coordinated turns. Flight
tests confirm the controller's effectiveness in transitioning from hovering to
forward flight, achieving desired vertical and lateral accelerations, and
reverting to hovering
Intraoperative Complications and Mid-Term Follow-Up of Large-Diameter Head Metal-on-Metal Total Hip Arthroplasty and Hip Resurfacing Arthroplasty
Background and Aims: Large-diameter head total hip arthroplasty and hip resurfacing arthroplasty were popular in Finland from 2000 to 2012 for the treatment of hip osteoarthritis. The aim of this retrospective study was to investigate the mid-term survival of large-diameter head total hip arthroplasty patients operated on in three university hospitals and to compare these results to the survival of hip resurfacing arthroplasty patients. Material and Methods: A total of 3860 hip arthroplasties (3029 large-diameter head total hip arthroplasties in 2734 patients and 831 hip resurfacing arthroplasties in 757 patients) were operated on between January 2004 and December 2009. The mean follow-up was 4.3years (range: 0.3-8.0years) in the total hip arthroplasty group and 5.1years (range: 1.7-7.9years) in the hip resurfacing arthroplasty group. Cox multiple regression model and Kaplan-Meier survival analysis were used to study the survival of the total hip arthroplasties and the hip resurfacing arthroplasties. Intraoperative complications and reasons for revisions were also evaluated. Results: In Cox regression analysis, the hazard ratio for revision of hip resurfacing arthroplasty was 1.5 compared with large-diameter head total hip arthroplasty (95% confidence interval: 1.0-2.2) (p=0.029). The cumulative Kaplan-Meier survival rate was 90.7% at 7.7years for the large-diameter head total hip arthroplasty (95% confidence interval: 86.8-94.6) and 92.2% at 7.6years for hip resurfacing arthroplasty (95% confidence interval: 89.9-94.6). There were a total of 166/3029 (5.5%) intraoperative complications in the large-diameter head total hip arthroplasty group and 20/831 (2.4%) in the hip resurfacing arthroplasty group (p=0.001). Revision for any reason was performed on 137/3029 (4.5%) of the arthroplasties in the large-diameter head total hip arthroplasty group and 52/831 (6.3%) in the hip resurfacing arthroplasty group (p=0.04). Conclusion: The mid-term survival of both of these devices was poor, and revisions due to adverse reactions to metal debris will most likely rise at longer follow-up. There were more intraoperative complications in the large-diameter head total hip arthroplasty group than in the hip resurfacing arthroplasty group.Peer reviewe
Life history of Megamelus scutellaris with description of immature stages (Hemiptera: Delphacidae)
The five immature stages of Megamelus scutellaris Berg (Hemiptera: Delphacidae) are described and illustrated. The main characters that distinguish the various stages are body size, number of tarsomeres and tibial spines, color, and number of teeth on the metatibial spur. New biological data based on laboratory rearing and field observations show that M. scutellaris can carry out its biological cycle successfully on water hyacinth, Eichhornia crassipes (Martius) Solms Laubach (Pontederiaceae). Mating occurs close to the water level and one to four eggs per scar are laid in apical portion of petiole and pseudolaminae. Ovipositional scars are recognized by three parallel marks. In addition, the efficient rearing in captivity, the high survivorship registered, and overwintering on only water hyacinth suggest M. scutellaris as a potential biocontrol agent of this invasive aquatic weed.Facultad de Ciencias Naturales y Muse
Abundance and Species Richness of Leafhoppers and Planthoppers (Hemiptera: Cicadellidae and Delphacidae) in Brazilian Maize Crops
Fil: De Oliveira, Charles Martins. Embrapa Cerrados. Planaltina. Brasília/DF; BrazilFil: De Oliveira, Elizabeth. Embrapa Milho e Sorgo. Sete Lagoas/MG; BrazilFil: Prazeres De Souza, Isabel Regina. Embrapa Milho e Sorgo. Sete Lagoas/MG; BrazilFil: Alves, Elcio. DuPont do Brazil S.A. DivisÆo Pioneer Sementes. Itumbiara/GO; BrazilFil: Dolezal, William. Pioneer Hi-Bred International. Itumbiara/GO; BrazilFil: Paradell, Susana Liria. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Marino de Remes Lenicov, Ana María. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Frizzas, Marina Regina. Universidade de Brasília. Departamento de Zoologia. Instituto de Ciências Biológicas. Brasília/DF; Brazi
Life history of Megamelus scutellaris with description of immature stages (Hemiptera: Delphacidae)
The five immature stages of Megamelus scutellaris Berg (Hemiptera: Delphacidae) are described and illustrated. The main characters that distinguish the various stages are body size, number of tarsomeres and tibial spines, color, and number of teeth on the metatibial spur. New biological data based on laboratory rearing and field observations show that M. scutellaris can carry out its biological cycle successfully on water hyacinth, Eichhornia crassipes (Martius) Solms Laubach (Pontederiaceae). Mating occurs close to the water level and one to four eggs per scar are laid in apical portion of petiole and pseudolaminae. Ovipositional scars are recognized by three parallel marks. In addition, the efficient rearing in captivity, the high survivorship registered, and overwintering on only water hyacinth suggest M. scutellaris as a potential biocontrol agent of this invasive aquatic weed.Facultad de Ciencias Naturales y Muse
- …