International Journal of Science and Engineering, 2012
This paper proposes a tracking controller for obstacle avoidance of a quadruped robot using poten... more This paper proposes a tracking controller for obstacle avoidance of a quadruped robot using potential functions method. The followings are done for this task. At first, a ceiling-mounted camera system is installed for image processing. The goal point and obstacles are separated and recognized by a color recognition method. Second, a path planning algorithm using potential functions method is proposed to generate the path to avoid obstacles and to plan a path for the quadruped robot to reach from start point to goal point. Third, a quadruped robot is chosen as the mobile platform for this study and the kinematic model for the robot is presented. Fourth, a tracking controller is designed for the quadruped robot to track the trajectory based on the backstepping method using Lyapunov function. Finally, the simulation results are presented to show the effectiveness of the proposed trajectory planning algorithm and the tracking controller.
ABSTRACT This paper proposes a tracking controller for obstacle avoidance of an omni-directional ... more ABSTRACT This paper proposes a tracking controller for obstacle avoidance of an omni-directional mobile vehicle (OMV) using potential function method through a ceiling-mounted camera system. To do this task, the followings were done. At first, for image processing, a ceiling-mounted camera system was installed to get images. The goal point and obstacles were separated and recognized by a color recognition method. Second, potential function method was proposed to generate the shortest path to avoid obstacles from the start point to the goal point. The mobile platform is a mecanum wheel omni-directional vehicle. Third, the tracking controller is designed for the OMV to track a trajectory generated by a path planning algorithm based on the backstepping method using Lyapunov function. Finally, the simulation results were presented to show the effectiveness of the proposed trajectory planning algorithm and tracking controller for obstacle avoidance of the OMV.
International Journal of Engineering and Industries, 2012
ABSTRACT This paper proposes a controller design for an omnidirectional mobile platform (OMP) wit... more ABSTRACT This paper proposes a controller design for an omnidirectional mobile platform (OMP) with three wheels using adaptive backstepping control. A kinematic modeling and a dynamic modeling of the system with disturbance and friction are presented. Based on the dynamic modeling, an adaptive backstepping controller (ABC) is designed to stabilize the OMP with parameter variations and uncertainties caused by friction and slip to follow a desired path. The controller and update laws are designed based on an adaptive backstepping control theory. It includes two steps: firstly, a virtual state and a stability function are introduced. Secondly, Lyapunov functions for the system are chosen and an adaptive backstepping controller to make the system stabilisable and the update laws to estimate the unknown parameters are obtained. The system stability is guaranteed by the Lyapunov stability theory. The simulation and experimental results are presented to demonstrate the effectiveness of the proposed controller and update laws.
Ninety-six weaned (21-23 days of age) piglets (L × Y) from 12 litters were divided into 4 groups ... more Ninety-six weaned (21-23 days of age) piglets (L × Y) from 12 litters were divided into 4 groups and fed a piglet diet ad libitum without and with supplementation of 600 ppm of one of three selected probiotic complexes in a 35-day growth trial. Piglets fed probiotic diets had higher feed intake and daily gain, and better feed conversion, than the control group (P b 0.05) during the 1st two weeks after weaning. There was no effect of probiotic supplementation on performance (P N 0.05) during weeks 3 to 5 after weaning. The concentration of lactic and acetic acid was higher (P b 0.05) in ileum and colon of piglets fed probiotic diets on days 14 and 35, while propionic acid was higher only in the ileum on day 35 (P b 0.05). There were no differences among the different probiotic complexes (P N 0.05).
The impact of supplementing a diet with lactic acid bacteria (LAB) complexes of LAB selected for ... more The impact of supplementing a diet with lactic acid bacteria (LAB) complexes of LAB selected for probiotic properties, on growth performance, digestibility, gut environment and health status was studied in weaned piglets. Ninety-six (48 females and 48 males) piglets (L × Y) from 12 litters, weaned at 21-23 days of age (6.6 ± 0.5 kg body weight), were selected and divided randomly into 4 groups balanced for sex, weight and litter origin. In each group, the piglets were divided randomly into 4 pens (replicates), and each group was fed one of 4 diets for 35 days. A basal diet without antibiotics or probiotics was used as control, and the other 3 groups were fed the control diet supplemented with 600 ppm of one of three different LAB complexes, comprising combinations of Enterococcus faecium 6H2, Lactobacillus acidophilus C3, Pediococcus pentosaceus D7, L. plantarum 1K8 and L. plantarum 3K2. Supplementation with LAB complexes increased (P < 0.05) daily feed intake and weight gain and improved feed conversion ratio, but there were no differences among the LAB treatments (P > 0.05). In the first 2 weeks after weaning, supplementation with LAB complexes increased (P < 0.05) the ileal apparent digestibility of crude protein (CP), crude fibre (CF) and organic matter, and the total tract apparent digestibility of CP and CF. Supplementation with LAB complexes increased the LAB counts at all sampling sites (P < 0.05) at days 14 and 35 post-weaning and increased the concentrations of lactic acid and acetic acid (P < 0.05) in ileum and colon. Counts of E. coli remained unaffected by LAB complex supplementation (P > 0.05). In the first 2 weeks after weaning, piglets fed diets supplemented with LAB complexes were less affected by diarrhoea than piglets fed the control diet suggesting that the LAB complexes tested have probiotic properties in weaned piglets.
Journal of Mechanical Science and Technology, 2012
In this paper, stabilization of a 2-degrees-of-freedom (2-DOF) omnidirectional mobile inverted pe... more In this paper, stabilization of a 2-degrees-of-freedom (2-DOF) omnidirectional mobile inverted pendulum (OM-IP) is studied. The OM-IP consists of the rod that rotates around a rotary point of a universal joint which is connected at the center of the omnidirectional mobile platform (OMP). For ease of analysis, the OM-IP is decoupled into two subsystems: a 2-DOF inverted pendulum (IP) and an OMP. The IP is a rod that rotates around a universal joint with 2-DOF. The OMP is a body consisting of disk and three omnidirectional wheels that moves on plane and keeps the rod in balance. Dynamic modeling of the 2-DOF OM-IP is presented. From the dynamic equation, an adaptive backstepping control method is proposed to keep the rod in balance. Update law is presented as differential equation of an unknown parameter when the distance from the center of gravity of the rod to the rotary point on the OMP is unknown. Stability of the adaptive controller is proven by using Lyapunov function. Simulation and experimental results show the effectiveness of the proposed controller.
Probiotics are live microorganisms which have been found to confer a health benefit on the host w... more Probiotics are live microorganisms which have been found to confer a health benefit on the host when administered in adequate amounts (Weichselbaum, 2009). Probiotics are mainly used to reinforce or re-establish the gut microbial balance, especially when the hosts are ...
Background. Mortality is high in HIV-infected TB patients, but few studies from Southeast Asia ha... more Background. Mortality is high in HIV-infected TB patients, but few studies from Southeast Asia have documented the benefits of interventions, such as co-trimoxazole (CTX), in reducing mortality during TB treatment. To help guide policy in Vietnam, we studied the epidemiology of HIV-associated TB in one province and examined factors associated with outcomes, including the impact of CTX use. Methodology/Principal Findings. We retrospectively abstracted data for all HIV-infected persons diagnosed with TB from 2001-2004 in An Giang, a province in southern Vietnam in which TB patients receive HIV counseling and testing. We used standard WHO definitions to classify TB treatment outcomes. We conducted multivariate analysis to identify risk factors for the composite outcome of death, default, or treatment failure during TB treatment. From 2001From -2004 HIV-infected TB patients were diagnosed in An Giang. Of these, 501 (79%) were male, 321 (50%) were aged 25-34 years, and the most common self-reported HIV risk factor was sex with a commercial sex worker in 221 (35%). TB was classified as smear-positive in 531 (83%). During TB treatment, 167 (26%) patients died, 9 (1%) defaulted, and 6 (1%) failed treatment. Of 454 patients who took CTX, 116 (26%) had an unsuccessful outcome compared with 33 (70%) of 47 patients who did not take CTX (relative risk, 0.4; 95% confidence interval [CI], 0.3-0.5). Adjusting for male sex, rural residence, TB smear status and disease location, and the occurrence of adverse events during TB treatment in multivariate analysis, the benefit of CTX persisted (adjusted odds ratio for unsuccessful outcome 0.1; CI, 0.1-0.3). Conclusions/Significance. In An Giang, Vietnam, HIV-associated TB was associated with poor TB treatment outcomes. Outcomes were significantly better in those taking CTX. This finding suggests that Vietnam should consider applying WHO recommendations to prescribe CTX to all HIV-infected TB patients.
This paper proposes a controller design for an omnidirectional mobile platform (OMP) with three w... more This paper proposes a controller design for an omnidirectional mobile platform (OMP) with three wheels using adaptive backstepping control. A kinematic modeling and a dynamic modeling of the system with disturbance and friction are presented. Based on the dynamic modeling, an adaptive backstepping controller (ABC) is designed to stabilize the OMP with parameter variations and uncertainties caused by friction and slip to follow a desired path. The controller and update laws are designed based on an adaptive backstepping control theory. It includes two steps: firstly, a virtual state and a stability function are introduced. Secondly, Lyapunov functions for the system are chosen and an adaptive backstepping controller to make the system stabilisable and the update laws to estimate the unknown parameters are obtained. The system stability is guaranteed by the Lyapunov stability theory. The simulation and experimental results are presented to demonstrate the effectiveness of the proposed controller and update laws.
International Journal of Science and Engineering, 2012
This paper proposes a tracking controller for obstacle avoidance of a quadruped robot using poten... more This paper proposes a tracking controller for obstacle avoidance of a quadruped robot using potential functions method. The followings are done for this task. At first, a ceiling-mounted camera system is installed for image processing. The goal point and obstacles are separated and recognized by a color recognition method. Second, a path planning algorithm using potential functions method is proposed to generate the path to avoid obstacles and to plan a path for the quadruped robot to reach from start point to goal point. Third, a quadruped robot is chosen as the mobile platform for this study and the kinematic model for the robot is presented. Fourth, a tracking controller is designed for the quadruped robot to track the trajectory based on the backstepping method using Lyapunov function. Finally, the simulation results are presented to show the effectiveness of the proposed trajectory planning algorithm and the tracking controller.
ABSTRACT This paper proposes a tracking controller for obstacle avoidance of an omni-directional ... more ABSTRACT This paper proposes a tracking controller for obstacle avoidance of an omni-directional mobile vehicle (OMV) using potential function method through a ceiling-mounted camera system. To do this task, the followings were done. At first, for image processing, a ceiling-mounted camera system was installed to get images. The goal point and obstacles were separated and recognized by a color recognition method. Second, potential function method was proposed to generate the shortest path to avoid obstacles from the start point to the goal point. The mobile platform is a mecanum wheel omni-directional vehicle. Third, the tracking controller is designed for the OMV to track a trajectory generated by a path planning algorithm based on the backstepping method using Lyapunov function. Finally, the simulation results were presented to show the effectiveness of the proposed trajectory planning algorithm and tracking controller for obstacle avoidance of the OMV.
International Journal of Engineering and Industries, 2012
ABSTRACT This paper proposes a controller design for an omnidirectional mobile platform (OMP) wit... more ABSTRACT This paper proposes a controller design for an omnidirectional mobile platform (OMP) with three wheels using adaptive backstepping control. A kinematic modeling and a dynamic modeling of the system with disturbance and friction are presented. Based on the dynamic modeling, an adaptive backstepping controller (ABC) is designed to stabilize the OMP with parameter variations and uncertainties caused by friction and slip to follow a desired path. The controller and update laws are designed based on an adaptive backstepping control theory. It includes two steps: firstly, a virtual state and a stability function are introduced. Secondly, Lyapunov functions for the system are chosen and an adaptive backstepping controller to make the system stabilisable and the update laws to estimate the unknown parameters are obtained. The system stability is guaranteed by the Lyapunov stability theory. The simulation and experimental results are presented to demonstrate the effectiveness of the proposed controller and update laws.
Ninety-six weaned (21-23 days of age) piglets (L × Y) from 12 litters were divided into 4 groups ... more Ninety-six weaned (21-23 days of age) piglets (L × Y) from 12 litters were divided into 4 groups and fed a piglet diet ad libitum without and with supplementation of 600 ppm of one of three selected probiotic complexes in a 35-day growth trial. Piglets fed probiotic diets had higher feed intake and daily gain, and better feed conversion, than the control group (P b 0.05) during the 1st two weeks after weaning. There was no effect of probiotic supplementation on performance (P N 0.05) during weeks 3 to 5 after weaning. The concentration of lactic and acetic acid was higher (P b 0.05) in ileum and colon of piglets fed probiotic diets on days 14 and 35, while propionic acid was higher only in the ileum on day 35 (P b 0.05). There were no differences among the different probiotic complexes (P N 0.05).
The impact of supplementing a diet with lactic acid bacteria (LAB) complexes of LAB selected for ... more The impact of supplementing a diet with lactic acid bacteria (LAB) complexes of LAB selected for probiotic properties, on growth performance, digestibility, gut environment and health status was studied in weaned piglets. Ninety-six (48 females and 48 males) piglets (L × Y) from 12 litters, weaned at 21-23 days of age (6.6 ± 0.5 kg body weight), were selected and divided randomly into 4 groups balanced for sex, weight and litter origin. In each group, the piglets were divided randomly into 4 pens (replicates), and each group was fed one of 4 diets for 35 days. A basal diet without antibiotics or probiotics was used as control, and the other 3 groups were fed the control diet supplemented with 600 ppm of one of three different LAB complexes, comprising combinations of Enterococcus faecium 6H2, Lactobacillus acidophilus C3, Pediococcus pentosaceus D7, L. plantarum 1K8 and L. plantarum 3K2. Supplementation with LAB complexes increased (P < 0.05) daily feed intake and weight gain and improved feed conversion ratio, but there were no differences among the LAB treatments (P > 0.05). In the first 2 weeks after weaning, supplementation with LAB complexes increased (P < 0.05) the ileal apparent digestibility of crude protein (CP), crude fibre (CF) and organic matter, and the total tract apparent digestibility of CP and CF. Supplementation with LAB complexes increased the LAB counts at all sampling sites (P < 0.05) at days 14 and 35 post-weaning and increased the concentrations of lactic acid and acetic acid (P < 0.05) in ileum and colon. Counts of E. coli remained unaffected by LAB complex supplementation (P > 0.05). In the first 2 weeks after weaning, piglets fed diets supplemented with LAB complexes were less affected by diarrhoea than piglets fed the control diet suggesting that the LAB complexes tested have probiotic properties in weaned piglets.
Journal of Mechanical Science and Technology, 2012
In this paper, stabilization of a 2-degrees-of-freedom (2-DOF) omnidirectional mobile inverted pe... more In this paper, stabilization of a 2-degrees-of-freedom (2-DOF) omnidirectional mobile inverted pendulum (OM-IP) is studied. The OM-IP consists of the rod that rotates around a rotary point of a universal joint which is connected at the center of the omnidirectional mobile platform (OMP). For ease of analysis, the OM-IP is decoupled into two subsystems: a 2-DOF inverted pendulum (IP) and an OMP. The IP is a rod that rotates around a universal joint with 2-DOF. The OMP is a body consisting of disk and three omnidirectional wheels that moves on plane and keeps the rod in balance. Dynamic modeling of the 2-DOF OM-IP is presented. From the dynamic equation, an adaptive backstepping control method is proposed to keep the rod in balance. Update law is presented as differential equation of an unknown parameter when the distance from the center of gravity of the rod to the rotary point on the OMP is unknown. Stability of the adaptive controller is proven by using Lyapunov function. Simulation and experimental results show the effectiveness of the proposed controller.
Probiotics are live microorganisms which have been found to confer a health benefit on the host w... more Probiotics are live microorganisms which have been found to confer a health benefit on the host when administered in adequate amounts (Weichselbaum, 2009). Probiotics are mainly used to reinforce or re-establish the gut microbial balance, especially when the hosts are ...
Background. Mortality is high in HIV-infected TB patients, but few studies from Southeast Asia ha... more Background. Mortality is high in HIV-infected TB patients, but few studies from Southeast Asia have documented the benefits of interventions, such as co-trimoxazole (CTX), in reducing mortality during TB treatment. To help guide policy in Vietnam, we studied the epidemiology of HIV-associated TB in one province and examined factors associated with outcomes, including the impact of CTX use. Methodology/Principal Findings. We retrospectively abstracted data for all HIV-infected persons diagnosed with TB from 2001-2004 in An Giang, a province in southern Vietnam in which TB patients receive HIV counseling and testing. We used standard WHO definitions to classify TB treatment outcomes. We conducted multivariate analysis to identify risk factors for the composite outcome of death, default, or treatment failure during TB treatment. From 2001From -2004 HIV-infected TB patients were diagnosed in An Giang. Of these, 501 (79%) were male, 321 (50%) were aged 25-34 years, and the most common self-reported HIV risk factor was sex with a commercial sex worker in 221 (35%). TB was classified as smear-positive in 531 (83%). During TB treatment, 167 (26%) patients died, 9 (1%) defaulted, and 6 (1%) failed treatment. Of 454 patients who took CTX, 116 (26%) had an unsuccessful outcome compared with 33 (70%) of 47 patients who did not take CTX (relative risk, 0.4; 95% confidence interval [CI], 0.3-0.5). Adjusting for male sex, rural residence, TB smear status and disease location, and the occurrence of adverse events during TB treatment in multivariate analysis, the benefit of CTX persisted (adjusted odds ratio for unsuccessful outcome 0.1; CI, 0.1-0.3). Conclusions/Significance. In An Giang, Vietnam, HIV-associated TB was associated with poor TB treatment outcomes. Outcomes were significantly better in those taking CTX. This finding suggests that Vietnam should consider applying WHO recommendations to prescribe CTX to all HIV-infected TB patients.
This paper proposes a controller design for an omnidirectional mobile platform (OMP) with three w... more This paper proposes a controller design for an omnidirectional mobile platform (OMP) with three wheels using adaptive backstepping control. A kinematic modeling and a dynamic modeling of the system with disturbance and friction are presented. Based on the dynamic modeling, an adaptive backstepping controller (ABC) is designed to stabilize the OMP with parameter variations and uncertainties caused by friction and slip to follow a desired path. The controller and update laws are designed based on an adaptive backstepping control theory. It includes two steps: firstly, a virtual state and a stability function are introduced. Secondly, Lyapunov functions for the system are chosen and an adaptive backstepping controller to make the system stabilisable and the update laws to estimate the unknown parameters are obtained. The system stability is guaranteed by the Lyapunov stability theory. The simulation and experimental results are presented to demonstrate the effectiveness of the proposed controller and update laws.
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