1,130 research outputs found
From Robot Arm to Intentional Agent: the Articulated Head
Robot arms have come a long way from the humble beginnings of the first Unimate robot at a General Motors plant installed to unload parts from a die-casting machine to the flexible and versatile tool ubiquitous and indispensable in many fields of industrial production nowadays. The other chapters of this book attest to the progress in the field and the plenitude of applications of robot arms. It is still fair, however, to say that currently industrial robot arms are primarily applied in continuously repeated manufacturing task for which they are pre-programmed. They are known for their precision and reliability but in general use only limited sensory input and the changes in the execution of their task due to varying environmental factors are minimal. If one was to compare a robot arm with an animal, even a very simple one, this property of robot arm applications would immediately stand out as one of the most striking differences. Living organisms must sense changes in the environment that are crucial to their survival and must have some flexibility to adjust their behaviour. In most robot arm contexts, such a comparison is currently at best of academic interest, though it might gain relevance very quickly in the future if robot arms are to be used to assist humans to a larger extend than at present. If robot arms will work in close proximity with and directly supporting humans in accomplishing a task, it becomes inevitable for the control system of the robot to have far reaching situational awareness and the capability to adjust its ‘behaviour’ according to the acquired situational information. In addition, robot perception and action have to conform a large degree to the expectations of the human co-worker
Investigation of the agricultural resources in Sri Lanka
The author has identified the following significant results. Several in-house capabilities were developed. The facilities to prepare color composites of excellent quality were developed, using bulk B/W 70 mm transparencies or 1:1,000,000 positive transparencies. These color composites were studied through optical devices on light tables. A zoom transfer scope was also added, enabling direct transfer of LANDSAT composite data on to base maps
Attitudes on euthanasia among medical students and doctors in Sri Lanka: a cross sectional study
Background: Euthanasia is a topic of intense ethical debate and it is illegal in most countries at present, including Sri Lanka. The aim of this descriptive cross-sectional study of medical students and practicing doctors was to explore the acceptance of euthanasia and physician assisted suicide (PAS), and factors influencing this opinion. Methods: A customised online questionnaire which explored opinions on euthanasia was administered to first and final year medical undergraduates in University of Colombo and practicing doctors with more than 5 years of work experience at The National Hospital of Sri Lanka. Attitudes on euthanasia and PAS were also assessed with the attitudes towards euthanasia (ATE) Scale, which is a 10-item questionnaire. Results: A total of 425 individuals responded (males: 178, 42%, age: median – 27 years), which included 143 (33.6%) first-year medical undergraduates, 141 (33.2%) final-year medical undergraduates and 141 (33.2%) practicing doctors. More participants (200, 47.1%) favoured legalizing euthanasia than those directly opposing it (110, 25.9%), but a significant proportion (27%) remained undecided. The mean scores of ATE questionnaire from the whole sample were generally unfavourable towards euthanasia/PAS. Accepting euthanasia as an option for oneself (p = < 0.001) was the strongest predictor of favouring euthanasia/PAS or supporting its legalization. Conclusion: In this cross-sectional survey, more respondents supported legalisation of euthanasia in Sri Lanka than those openly opposing it. Yet, a significant minority that responded as “undecided” for legalisation, were more likely to have unfavourable ATE
Localization and tracking of agents for close range applications
This research investigates the state estimation problem in close-range involving multiple targets using Doppler Radar. As the main theme is based on measurements with linear sensor arrays, optimal sensor arrangements are studied for two most popular measurement technologies: Angle-of-Arrival and range based localization systems
Estimation of body weight using anthropometric parameters in Sri Lankan hospitalized adult patients
Body weight is an important clinical parameter for accurate dosing of drugs with a narrow therapeutic window, However, it is difficult to measure the body weight of a patient if they cannot stand on a scale. There are several anthropometrics-based equations to estimate the body weight, but most of these are derived from white Caucasian populations and are not validated for South Asians. This study aimed to validate existing anthropometrics-based weight estimation equations and develop a new equation for the same purpose for Sri Lankan adults. This prospective study was conducted at the National Hospital of Sri Lanka over a 6-month period, split into a development and a validation phase. During the development phase, estimated body weight of patients by doctors and nurses and patients themselves were noted and compared against their actual body weight. In addition, 13 anthropometric measurements were taken, which were used to validate 12 anthropometrics-based equations to estimate body weight described in literature previously. Two new gender specific regression models to estimate the body weight in the local population was also derived and validated. A total of 502 (males = 249) and 217 (males = 108) patients were recruited for the development and validation phases respectively. Both doctors and patients had comparable accuracy in predicting body weight (p>0.05). All anthropometric based equations were significantly correlated with actual body weight (correlation coefficients: 0.741–0.869), and the new equations derived from the local data performed similarly to the best performing equation identified from the literature during validation phase. However, even the best of these equations could not outperform patient/physician estimates. When the patient weight cannot be measured, an estimate by the patient or the doctor may be the best substitute
The effect of an infra-acetabular screw for anatomically shaped three-dimensional plate or standard plate designs in acetabulum fractures: a biomechanical analysis
Background
Various plate shapes and implant configurations are used for stabilization of acetabulum fractures via anterior approaches. Little is known about the biomechanical stability of a two-dimensionally shaped “conventional” plate (“J-Plate”—JP) in comparison to three-dimensionally shaped plate configurations (3DP). In addition, the augmentary effect of an infra-acetabular lag-screw (IACS) fixation for anterior column and posterior hemi-transverse acetabulum fractures has not been clarified in comparison of JP and 3DP constructs. This study analyzed the difference between the biomechanical stability of JP compared to 3DP and the role of an IACS in a standardized acetabular fracture model in a single-leg stance loading configuration.
Methods
In an artificial bone substitute pelvis model (Synbone© Malans, Switzerland), a typical and standardized fracture pattern (anterior column and posterior hemi-transverse) was created with osteotomy jigs. After anatomic reduction the stabilization was performed using JP or 3DP. Eight pelvises per group were axially loaded in a single-leg stance model up to 400 N. After the load cycle, an additional infra-acetabular screw was placed and the measurement repeated. Fragment displacement was recorded by an optical tracking system (Optitrack Prime 13®, Corvallis, USA).
Results
In the pure placement, 3DP provided significantly superior stability when compared to JP. Augmentation of JP by IACS increased the stability significantly, up to the level of 3DP alone, whereas augmentation of the 3DP did not result in further increase of overall stability.
Conclusion
The anatomically shaped plate alone provides a superior biomechanical stability in fixation of an anterior column and posterior hemi-transverse fracture model. In a JP fixation the augmentation by IACS provides similar strength as the anatomically shaped 3DP. By use of the anatomically shaped 3DP the need of a clinically risky application of IACS might be avoidable
Incorporating plantain into ryegrass-white clover mixed sward for an economically and environmentally sustainable dairy system: Year one of a farm system study
The objective of this replicated farm system study was to investigate the effect of increasing proportion of plantain (Plantago lanceolata L. cv. Ecotain) in a perennial ryegrass/white clover (RGWC) mixed sward on farm productivity, profitability and environmental footprint over the 2021/22 production season. A total of 108 dairy cows were blocked into nine herds of 12 cows. The herds were randomly allocated into one of three replicated pasture treatments sown with an increasing plantain seed rate: (i) RGWC with nil plantain (PL0); (ii) RGWC+3 kg/ha plantain seed rate (PL3) or (iii) RGWC+6 kg/ha plantain seed rate (PL6). Farmlet milk and pasture production were measured, and data was used to estimate farm profitability and environmental footprint using FARMAX and OverseerEd software, respectively. Increasing plantain seed rate from 3 to 6 kg/ha increased sward content of plantain from 24% to 34% of DM in PL3 and PL6, respectively. Pasture production (average 12,988±473 kg DM/ha), total milk solids production (1,356±40 kg/ha) and farm profitability (4,347±354 NZ$/ha) were similar amongst treatments. Compared to PL0, estimated annual nitrogen leaching and nitrous oxide emissions were reduced by 21% and 30%, (P<0.001) and 4.3% and 6.0% (P<0.01) in PL3 and PL6, respectively. Results suggest that incorporation of plantain into dairy systems could be used as a strategy to reduce predicted environmental footprint while maintaining profitability. However, these results need to be confirmed over multiple production seasons
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