77 research outputs found

    An Approach for Multi-Robot Opportunistic Coexistence in Shared Space

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    This thesis considers a situation in which multiple robots operate in the same environment towards the achievement of different tasks. In this situation, please consider that not only the tasks, but also the robots themselves are likely be heterogeneous, i.e., different from each other in their morphology, dynamics, sensors, capabilities, etc. As an example, think about a "smart hotel": small wheeled robots are likely to be devoted to cleaning floors, whereas a humanoid robot may be devoted to social interaction, e.g., welcoming guests and providing relevant information to them upon request. Under these conditions, robots are required not only to co-exist, but also to coordinate their activity if we want them to exhibit a coherent and effective behavior: this may range from mutual avoidance to avoid collisions, to a more explicit coordinated behavior, e.g., task assignment or cooperative localization. The issues above have been deeply investigated in the Literature. Among the topics that may play a crucial role to design a successful system, this thesis focuses on the following ones: (i) An integrated approach for path following and obstacle avoidance is applied to unicycle type robots, by extending an existing algorithm [1] initially developed for the single robot case to the multi-robot domain. The approach is based on the definition of the path to be followed as a curve f (x;y) in space, while obstacles are modeled as Gaussian functions that modify the original function, generating a resulting safe path. The attractiveness of this methodology which makes it look very simple, is that it neither requires the computation of a projection of the robot position on the path, nor does it need to consider a moving virtual target to be tracked. The performance of the proposed approach is analyzed by means of a series of experiments performed in dynamic environments with unicycle-type robots by integrating and determining the position of robot using odometry and in Motion capturing environment. (ii) We investigate the problem of multi-robot cooperative localization in dynamic environments. Specifically, we propose an approach where wheeled robots are localized using the monocular camera embedded in the head of a Pepper humanoid robot, to the end of minimizing deviations from their paths and avoiding each other during navigation tasks. Indeed, position estimation requires obtaining a linear relationship between points in the image and points in the world frame: to this end, an Inverse Perspective mapping (IPM) approach has been adopted to transform the acquired image into a bird eye view of the environment. The scenario is made more complex by the fact that Pepper\u2019s head is moving dynamically while tracking the wheeled robots, which requires to consider a different IPM transformation matrix whenever the attitude (Pitch and Yaw) of the camera changes. Finally, the IPM position estimate returned by Pepper is merged with the estimate returned by the odometry of the wheeled robots through an Extened Kalman Filter. Experiments are shown with multiple robots moving along different paths in a shared space, by avoiding each other without onboard sensors, i.e., by relying only on mutual positioning information. Software for implementing the theoretical models described above have been developed in ROS, and validated by performing real experiments with two types of robots, namely: (i) a unicycle wheeled Roomba robot(commercially available all over the world), (ii) Pepper Humanoid robot (commercially available in Japan and B2B model in Europe)

    A systemic literature review of the effect of proton pump inhibitors on gallbladder function

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    Objective: To determine the association between proton pump inhibitors and gallbladder function Methods: A systematic search of Medline, Embase and CENTRAL (inception to April 2020) was conducted to capture the relevant studies. A comprehensive inclusion-exclusion criterion was developed and implemented to screen the titles and abstracts. . We, however, found no eligible studies. Results: The systematic search identified 38 unique articles for title and abstract screening. Of which, five were included as potentially relevant studies. However, upon full-text screening, none of them met our inclusion criteria. This review is, therefore, an empty systematic review. Conclusion: There are no good quality studies determining the effect of proton pump inhibitors on gallbladder function. Given the common use of proton pump inhibitors and their potential impact on gallbladder function, there is an urgent need for conducting clinical studies to address this gap in the evidence

    An Inverse Perspective Mapping Approach using Monocular Camera of Pepper Humanoid Robot to Determine the Position of Other Moving Robot in Plane

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    This article presents a method to know the position of object or moving robot in the plane while the camera is moving dynamically. An Inverse Perspective mapping (IPM) approach has been embedded in a monocular camera on Head of Pepper Humanoid Robot (Softbank Robotics) for real time position determination of other object or robot in plane. While the Pepper head is moving, it is difficult to determine position or distance to objects in front of the robot with any different degree of certainity. By applying IPM, a linear relationship between the IPM frame and world frame becomes the key element to know the position of object while the head is static but when the head orientation changes the IPM is modified to adapt the linear relationship between both frames. So, the proposed method is based on the extraction of accurate bird\u2019s-eye view. The method includes the Image Acquistion, IPM Filtering, Detection Phase, Region of Interest Selection and Pixel remapping

    Analysis of path following and obstacle avoidance for multiple wheeled robots in a shared workspace

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    The article presents the experimental evaluation of an integrated approach for path following and obstacle avoidance, implemented on wheeled robots. Wheeled robots are widely used in many different contexts, and they are usually required to operate in partial or total autonomy: in a wide range of situations, having the capability to follow a predetermined path and avoiding unexpected obstacles is extremely relevant. The basic requirement for an appropriate collision avoidance strategy is to sense or detect obstacles and make proper decisions when the obstacles are nearby. According to this rationale, the approach is based on the definition of the path to be followed as a curve on the plane expressed in its implicit form f(x, y) = 0, which is fed to a feedback controller for path following. Obstacles are modeled through Gaussian functions that modify the original function, generating a resulting safe path which - once again - is a curve on the plane expressed as f\u2032(x, y) = 0: the deformed path can be fed to the same feedback controller, thus guaranteeing convergence to the path while avoiding all obstacles. The features and performance of the proposed algorithm are confirmed by experiments in a crowded area with multiple unicycle-like robots and moving persons

    Big data and predictive analytics in healthcare in Bangladesh: regulatory challenges

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    Big data analytics and artificial intelligence are revolutionizing the global healthcare industry. As the world accumulates unfathomable volumes of data and health technology grows more and more critical to the advancement of medicine, policymakers and regulators are faced with tough challenges around data security and data privacy. This paper reviews existing regulatory frameworks for artificial intelligence-based medical devices and health data privacy in Bangladesh. The study is legal research employing a comparative approach where data is collected from primary and secondary legal materials and filtered based on policies relating to medical data privacy and medical device regulation of Bangladesh. Such policies are then compared with benchmark policies of the European Union and the USA to test the adequacy of the present regulatory framework of Bangladesh and identify the gaps in the current regulation. The study highlights the gaps in policy and regulation in Bangladesh that are hampering the widespread adoption of big data analytics and artificial intelligence in the industry. Despite the vast benefits that big data would bring to Bangladesh's healthcare industry, it lacks the proper data governance and legal framework necessary to gain consumer trust and move forward. Policymakers and regulators must work collaboratively with clinicians, patients and industry to adopt a new regulatory framework that harnesses the potential of big data but ensures adequate privacy and security of personal data. The article opens valuable insight to regulators, academicians, researchers and legal practitioners regarding the present regulatory loopholes in Bangladesh involving exploiting the promise of big data in the medical field. The study concludes with the recommendation for future research into the area of privacy as it relates to artificial intelligence-based medical devices should consult the patients' perspective by employing quantitative analysis research methodology. © 2021 The Author(s

    Effect of yeast supplementation on production parameters, egg quality characteristics and crude protein digestibility in hens

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    Background: Yeast (Saccharomyces cerevisiae) has a buffering effect in the digestive tract, and proper feed additives in chicken diets can improve the birds’ digestive efficiency. The present study planned with aim to investigate the effects of different levels of yeast supplementation on the egg production, egg quality traits and crude protein digestibility in hens.Methods: A total of 84 hens (40 weeks of age) were fed the dietary treatments until 50 weeks of age. The hens were distributed into 4 treatments and 3 replicates with 7 hens per experimental unit. The yeast was incorporated into basal feed with various levels (0, 0.1, 0.15 and 0.2%). The production data was obtained during trial. For determining egg quality characteristics, 30 eggs from each treatment group were used at 14-day interval of the experiment from a 2-day collection of eggs during the week. The excreta from each replicate were collected after every 2 weeks for determining the crude protein digestibility.Results: Maximum egg production and egg mass were attained from the hens provided 0.15% and 0.20% yeast supplementation. The eggshell thickness decreased with supplementation of yeast. Higher yolk weight, albumen weight, Haugh unit and grading values were observed at 0.2% level than other groups. Crude protein digestibility also improved at high levels of yeast supplementation at all ages.Conclusion: This study envisaged that yeast supplementation between 0.15 and 0.20% could be sufficient during 40 to 50 weeks of age, to augment the overall layer performance. Keywords: Baker’s yeast; feed intake; egg production; egg qualit

    Controlled Morphology and Its Effects on the Thermoelectric Properties of SnSe2 Thin Films

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    In the last few years, the thermoelectric properties of tin selenide (SnSe) have been explored in much detail due to its high efficiency and green nature, being free of Te and Pb. In the same chalcogenide family, SnSe2 is also a layered structured material, but its thermoelectric potential has not been widely explored experimentally. Since SnSe2 has the layered structure, its electrical transport properties may strongly be affected by its microstructure and morphology. Here, we report the effect of reaction time on the structure, phase, and morphology of the SnSe2 during solvothermal synthesis process. We have studied four SnSe2 samples with different reaction times. The sample obtained after 16 h of reaction time was named as M1, for 20 h M2, similarly for 24 h was M3 and for 48 hours’ time, the sample was named as M4. We investigated its thermoelectric properties and found that phase purity and morphology can affect the thermoelectric performance of the synthesized samples. The peak power factor (PF) value along the ab plane was (0.69 μWcm−1K−2) for the M4 sample at 575 K, which was the highest among all the measured samples. The comparatively larger PF value of sample M4 can be related to the increase in its electrical conductivity due to increase in phase purity and band gap reduction

    Nonlinear Structure based Artificial Neural Computing for Upstream Flow Functional Models

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    Most of the real world systems are nonlinear and complex and it is challenging to model these types of systems for analyzing and forecasting the hidden behaviour of the systems. In the paradigm of vague complex systems, data-based time series modeling approaches of intelligent systems showed its applicability for coping with the problems of hidden noise and dynamicity which are encapsulated in the data. Getting from nature is one of the humans’ features and they are striving to produce the intellectual schemes by coping rare features of cognitions and intellect of the brain. In this paper, nonlinear autoregressive structure based modeling of the brain (i.e. Artificial Neural Network) is the aim of this study that suggest various Dynamic Neural Network (DNN) models by using time deferred autoregressive configurations, for the stream-flow of Sukkur barrage on lower Indus river basin. The suitability of the models for training, validation and testing stages, are evinced on assessment metrics which demonstrate the accuracy and sufficiency of the models which may be beneficial for water-resource management

    Adsorption of paracetamol on activated charcoal in the presence of dextropropoxyphene hydrochloride, N-acetylcysteine and sorbitol

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    Paracetamol, an over the counter analgesic and antipyretic drug, causes hepatic and renal tubular necrosis at higher doses ingested accidentally, or intentionally. The situation worsens clinically upon the ingestion of product containing paracetamol and dextropropoxyphene. In paracetamol poisoning, activated charcoal is used to adsorb the drug from the gastrointestinal tract, sorbitol to remove charcoaldrug complexes and N-acetylcysteine to reduce the drug and its metabolites from systemic circulation. Activated charcoal being non-specific adsorbent may adsorb other chemical moieties from the intestine as well as antidotes. Therefore, the present study aimed to investigate the adsorption of paracetamol on activated charcoal in presence of dextropropoxyphene hydrochloride, N-acetylcysteine and sorbitol. Paracetamol was combined separately with dextropropoxyphene hydrochloride, N-acetylcysteine and sorbitol. These mixtures were combined with varying amounts of activated charcoal to evaluate the in vitro adsorption of paracetamol using Langmuir Isotherm. Paracetamol adsorption was 96.6 % at charcoal-drug ratio (6:1) while only 2 % higher in 8:1 and 2.9 % in 10:1. The binding constant (K2), maximum adsorption capacity per gram of activated charcoal for paracetamol alone and in presence of dextropropoxyphene hydrochloride, N-acetylcysteine and sorbitol was found to be 366, 339, 313 and 355 mg/g, respectively. The results of the present study indicate that except sorbitol other investigated substances significantly reduce the adsorption of paracetamol on activated charcoal, which may be compensated by increasing the concentration of activated charcoal.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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