136 research outputs found
Behaviour-based control approach for the trajectory tracking of an underactuated planar capsule robot
A miniature capsule robot (capsubot) – which has no external moving parts whereas a conventional robot has legs and/or wheels – is suitable for in-vivo applications, engineering diagnosis and pipe inspection. This study addresses the trajectory-tracking problem of an underactuated planar capsubot. A combining piecewise and behaviour-based control algorithm is proposed for trajectory tracking. This study also proposes four motion behaviours, four switching behaviours and one stationary behaviour. A selection algorithm for behaviour-based control and rules for inner mass (IM) motion control in all the behaviours are developed. The partial feedback linearisation control is used for low-level IM motion control while the piecewise and behaviour-based control is used for the capsubot trajectory tracking control
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Bifidobacterial Dominance of the Gut in Early Life and Acquisition of Antimicrobial Resistance.
Bifidobacterium species are important commensals capable of dominating the infant gut microbiome, in part by producing acids that suppress growth of other taxa. Bifidobacterium species are less prone to possessing antimicrobial resistance (AMR) genes (ARGs) than other taxa that may colonize infants. Given that AMR is a growing public health crisis and ARGs are present in the gut microbiome of humans from early life, this study examines the correlation between a Bifidobacterium-dominated infant gut microbiome and AMR levels, measured by a culture-independent metagenomic approach both in early life and as infants become toddlers. In general, Bifidobacterium dominance is associated with a significant reduction in AMR in a Bangladeshi cohort, both in the number of acquired AMR genes present and in the abundance of AMR genes. However, by year 2, Bangladeshi infants had no significant differences in AMR related to their early-life Bifidobacterium levels. A generalized linear model including all infants in a previously published Swedish cohort found a significant negative association between log-transformed total AMR and Bifidobacterium levels, thus confirming the relationship between Bifidobacterium levels and AMR. In both cohorts, there was no change between early-life and later-life AMR abundance in high-Bifidobacterium infants but a significant reduction in AMR abundance in low-Bifidobacterium infants. These results support the hypothesis that early Bifidobacterium dominance of the infant gut microbiome may help reduce colonization by taxa containing ARGs.IMPORTANCE Infants are vulnerable to an array of infectious diseases, and as the gut microbiome may serve as a reservoir of AMR for pathogens, reducing the levels of AMR in infants is important to infant health. This study demonstrates that high levels of Bifidobacterium are associated with reduced levels of AMR in early life and suggests that probiotic interventions to increase infant Bifidobacterium levels have the potential to reduce AMR in infants. However, this effect is not sustained at year 2 of age in Bangladeshi infants, underscoring the need for more detailed studies of the biogeography and timing of infant AMR acquisition
Modelling and Motion Analysis of a Pill-Sized Hybrid Capsule Robot
This paper presents a miniature hybrid capsule robot for minimally invasive in-vivo interventions such as capsule endoscopy within the GI (gastrointestinal) tract. It proposes new modes of operation for the hybrid robot namely hybrid mode and anchoring mode. The hybrid mode assists the robot to open an occlusion or to widen a narrowing. The anchoring mode enables the robot to stay in a specific place overcoming external disturbances (e.g. peristalsis) for a better and prolonged observation. The modelling of the legged, hybrid and anchoring modes are presented and analysed. Simulation results show robot propulsions in various modes. The hybrid capsule robot consisting four operating modes is more effective for the locomotion and observation within GI tract when compared to the locomotion consisting a single mean of locomotion as the hybrid robot can switch among the operating modes to suit the situation/task
Associations between family social circumstances and psychological distress among the university students of Bangladesh : to what extent do the lifestyle factors mediate?
Background: While there is a growing body of empirical studies focusing on the social and behavioral predictors of psychological health, the mechanisms that may underlie the reported associations have not been adequately explored. This study aimed to examine the association of social and lifestyle factors with psychological distress, and the potential mediating role of the lifestyle factors in the estimated associations between social circumstances and psychological distress. Methods: A total of 742 tertiary level students (53% females) from a range of socio-economic backgrounds and multiple educational institutions participated in this cross-sectional study. The 12-items General Health Questionnaire (GHQ-12) was utilized for measuring psychological distress. Data related to students’ socio-demographic characteristics, family social circumstances, and lifestyle factors were also collected. Modified Poisson regression analysis was used to estimate the risk ratios (RR) and their 95% confidence intervals (CI). Results: The multivariable regression analysis suggests heightened risks of psychological distress associated with low parental Socio-Economic Position (SEP) (RR: 1.36; 95% CI: 1.07, 1.76), childhood poverty (RR: 1.31; 95% CI: 1.11, 1.55), and living away from the family (RR: 1.28; 95% CI: 1.07, 1.54). Among the lifestyle factors, past smoking, physical inactivity, inadequate fruit intake, and poor sleep quality were strongly associated with psychological distress and these associations persisted when the family social circumstances and lifestyle factors were mutually adjusted for. The lifestyle factors did not considerably mediate the estimated associations between family social circumstances and psychological distress. Conclusion: The social and lifestyle factors operated independently to increase students’ risk of psychological distress. Accordingly, while promoting students’ healthy lifestyles may reduce the overall burden of psychological distress, any equity initiative aiming to minimize the social inequalities in psychological health should be targeted to improving the living conditions in early life
Experimental evaluation of adaptive maximum power point tracking for a standalone photovoltaic system
The adaptability of maximum power point tracking (MPPT) of a solar PV system is important for integration to a microgrid. Depending on what fixed step-size the MPPT controller implements, there is an impact on settling time to reach the maximum power point (MPP) and the steady state operation for conventional tracking techniques. This paper presents experimental results of an adaptive tracking technique based on Perturb and Observe (P&O) and Incremental Conductance (IC) for standalone Photovoltaic (PV) systems under uniform irradiance and partial shading conditions. Analysis and verification of measured and MATLAB/Simulink simulation results have been carried out. The adaptive tracking technique splits the operational region of the solar PV’s power–voltage characteristic curve into four and six operational sectors to understand the MPP response and stability of the technique. By implementing more step-sizes at sector locations based on the distance of the sector from the MPP, the challenges associated with fixed step-size is improved on.The measured and simulation results clearly indicate that the proposed system tracks MPP faster and displays better steady state operation than conventional system. The proposed system’s tracking efficiency is over 10% greater than the conventional system for all techniques. The proposed system has been under partial shading condition has been and it outperforms other techniques with the GMPP achieved in 0.9 s which is better than conventional techniques
A review on impact of mining and mineral processing industries through life cycle assessment
This paper analysed and summarised the significant research outputs published on the environmental impact assessment of mining and mineral processing industries through life cycle assessment. The paper presents valuable insights in identifying the gaps, where should the focus be in the mining and mineral processing industries for a sustainable future. Mining and mineral processing industries have been the key focus of research in many countries due to its increasing sustainability concerns that affect global warming and climate change. Use of heavy equipment that consumes electrical energy, mechanical energy, and an enormous amount of process heat is a key contributor to the overall impacts in the industry. Due to the use of heavy equipment and associated energy consumption, these industrial sectors contribute notably to global warming, human health, ecosystems, and resources. Among the various environmental impact assessment tools which are widely used to identify sustainability indicators, life cycle assessment (LCA) is a well-justified approach among the practitioners and researchers. Though state of the art technological tools and resources are being used now a days, there is still a research gap in identifying the key mining processes which need to be the focus of attention. Renewable energy integration in the mineral processing sector and process heating from green energy sources is becoming the emergent field of research. The review results reveal, the assessment indicators in human health and ecosystems are key factors that are mostly missing in the previous studies which are crucial for people or community living nearby mining area. This review paper identifies the research gaps to the existing literature that can form the base for future research direction in the field of LCA and sustainable energy integration in mining and mineral processing industries
Changes in loneliness prevalence and its associated factors among Bangladeshi older adults during the COVID-19 pandemic
Aims Worldwide, loneliness is one of the most common psychological phenomena among older adults, adversely affecting their physical and mental health conditions during the COVID-19 pandemic. This study aims to assess changes in the prevalence of loneliness in the two timeframes (first and second waves of COVID-19 in Bangladesh) and identify its correlates in pooled data. Methods This repeated cross-sectional study was conducted on two successive occasions (October 2020 and September 2021), overlapping with the first and second waves of the COVID-19 pandemic in Bangladesh. The survey was conducted remotely through telephone interviews among 2077 (1032 in the 2020-survey and 1045 in the 2021-survey) older Bangladeshi adults aged 60 years and above. Loneliness was measured using the 3-item UCLA Loneliness scale. The binary logistic regression model was used to identify the factors associated with loneliness in pooled data. Results We found a decline in the loneliness prevalence among the participants in two survey rounds (51.5% in 2021 versus 45.7% in 2020; P = 0.008), corresponding to 33% lower odds in the 2021-survey (AOR 0.67, 95% CI 0.54-0.84). Still, nearly half of the participants were found to be lonely in the latest survey. We also found that, compared to their respective counterparts, the odds of loneliness were significantly higher among the participants without a partner (AOR 1.58, 95% CI 1.20-2.08), with a monthly family income less than 5000 BDT (AOR 2.34, 95% CI 1.58-3.47), who lived alone (AOR 2.17, 95% CI 1.34-3.51), with poor memory or concentration (AOR 1.58, 95% CI 1.23-2.03), and suffering from non-communicable chronic conditions (AOR 1.55, 95% CI 1.23-1.95). Various COVID-19-related characteristics, such as concern about COVID-19 (AOR 1.28, 95% CI 0.94-1.73), overwhelm by COVID-19 (AOR 1.53, 95% CI 1.14-2.06), difficulty earning (AOR 2.00, 95% CI 1.54-2.59), and receiving routine medical care during COVID-19 (AOR 2.08, 95% CI 1.61-2.68), and perception that the participants required additional care during the pandemic (AOR 2.93, 95% CI 2.27-3.79) were also associated with significantly higher odds of loneliness. However, the odds of loneliness were significantly lower among the participants with formal schooling (AOR 0.71, 95% CI 0.57-0.89) and with a family of more than four members (AOR 0.76, 95% CI 0.60-0.96). Conclusions The current study found a decreased prevalence of loneliness among Bangladeshi older adults during the ongoing pandemic. However, the prevalence is still very high. The findings suggest the need for mental health interventions that may include improving social interactions increasing opportunities for meaningful social connections with family and community members and providing psychosocial support to the vulnerable population including older adults during the pandemic. It also suggests that policymakers and public health practitioners should emphasise providing mental health services at the peripheral level where the majority of older adults reside
Solar Process Heat in Industrial Systems- A Global Review
In developing countries, industries and manufacturing sectors consume a major portion of the total consumption of energy, where most of the energy is used for low, medium or high temperature heat generation to be used for process applications known as process heat. The necessity to commercialize clean, cheap and efficient renewable sources of energy in industrial applications emerges from increasing concerns about greenhouse gas emissions and global warming and decreasing fossil fuel use in commercial sectors. As an abundant source of energy, solar energy technologies have proven potential. Recent research shows currently only a few industries are employing solar energy in industrial processes to generate process heat while replacing fossil fuels. Solar thermal power generation is already very well-known and getting popular in recent years while other potential applications of the concentrated heat from solar radiation are little explored. This review paper presents a detailed overview of the current potential and future aspects of involving solar industrial process heating systems in industrial applications. In order to keep pace with this emerging and fast growing sector for renewable energy applications, it is necessary to get in depth knowledge about the overall potential of industrial processes in individual industrial sector where solar process heat is currently in use and identifying industrial processes are most compatible for solar system integration depending on temperature level and the type of solar collector in use. Furthermore, the promising sectors needs to be identified for the use of solar heat using industrial processes for the integration of solar heat, so that countries with immense solar energy potential can use those technologies in future to reduce fossil fuel consumption and develop sustainable industrial systems. This paper presents a comprehensive review of the potential industrial processes that can adopt solar process heating systems and thus driving towards sustainable production in industries
Multi-scale pedestrian intent prediction using 3D joint information as spatio-temporal representation
There has been a rise of use of Autonomous Vehicles on public roads. With the predicted rise of road traffic accidents over the coming years, these vehicles must be capable of safely operate in the public domain. The field of pedestrian detection has significantly advanced in the last decade, providing high-level accuracy, with some technique reaching near-human level accuracy. However, there remains further work required for pedestrian intent prediction to reach human-level performance. One of the challenges facing current pedestrian intent predictors are the varying scales of pedestrians, particularly smaller pedestrians. This is because smaller pedestrians can blend into the background, making them difficult to detect, track or apply pose estimations techniques. Therefore, in this work, we present a novel intent prediction approach for multi-scale pedestrians using 2D pose estimation and a Long Short-term memory (LSTM) architecture. The pose estimator predicts keypoints for the pedestrian along the video frames. Based on the accumulation of these keypoints along the frames, spatio-temporal data is generated. This spatio-temporal data is fed to the LSTM for classifying the crossing behaviour of the pedestrians. We evaluate the performance of the proposed techniques on the popular Joint Attention in Autonomous Driving (JAAD) dataset and the new larger-scale Pedestrian Intention Estimation (PIE) dataset. Using data generalisation techniques, we show that the proposed technique outperformed the state-of-the-art techniques by up to 7%, reaching up to 94% accuracy while maintaining a comparable run-time of 6.1 ms
Prevalence and demographic, socioeconomic, and behavioral risk factors of self-reported symptoms of sexually transmitted infections (STIs) among ever-married women : evidence from nationally representative surveys in Bangladesh
Sexually transmitted infections (STI) symptoms (e.g., abnormal genital discharge and genital sores/ulcers) are a major public health concern in Bangladesh because the symptoms can indicate an STI and cause sexual and reproductive health complications in women of reproductive age. To our knowledge, no study examined the prevalence and risk factors of STI symptoms using a nationally representative sample. This study investigates the prevalence of STI symptoms among ever-married women in Bangladesh and the associations of STI symptoms with various demographic, socioeconomic, and behavioral risk factors using the most recent available data (2007, 2011, and 2014) of the Bangladesh Demographic and Health Surveys (BDHS). The BDHS employs a two stage stratified sampling technique. The analytic sample comprised 41,777 women of reproductive age (15–49 years). Outcome variables included STI symptoms: abnormal genital discharge and genital sores/ulcers. Multivariate logistic regression was employed to find the adjusted odds ratio with a 95% confidence interval to assess the associations of outcome measures with explanatory variables. The study found that the prevalence of abnormal genital discharge and genital sores/ulcers among ever-married women aged 15–49 years was 10% and 6%, respectively. Multivariable analysis revealed that for women aged 25–34 years, those who used contraceptives and married earlier had an increased likelihood of STI symptoms. Furthermore, women from the wealthiest wealth quintile and couple’s joint decision-making were less likely to have STI symptoms. Findings have implications for interventions efforts aiming to improve women’s sexual and reproductive health in Bangladesh
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