Mobile Robot Range Sensing through Visual Looming

This article describes and evaluates visual looming as a monocular range sensing method for mobile robots. The looming algorithm is based on the relationship between the displacement of a camera relative to an object, and the resulting change in the size of the object's image on the focal plane of the camera. We have carried out systematic experiments to evaluate the ranging accuracy of the looming algorithm using a Pioneer I mobile robot equipped with a color camera. We have also performed noise sensitivity for the looming algorithm, obtaining theoretical error bounds on the range estimates for given levels of odometric and visual noise, which were verified through experimental data. Our results suggest that looming can be used as a robust, inexpensive range sensor as a complement to sonar.Defense Advanced Research Projects Agency; Office of Naval Research; Navy Research Laboratory (00014-96-1-0772, 00014-95-1-0409

Mobile Robot Range Sensing through Visual Looming

This article describes and evaluates visual looming as a monocular range sensing method for mobile robots. The looming algorithm is based on the relationship between the displacement of a camera relative to an object, and the resulting change in the size of the object's image on the focal plane of the camera. We have carried out systematic experiments to evaluate the ranging accuracy of the looming algorithm using a Pioneer I mobile robot equipped with a color camera. We have also performed noise sensitivity for the looming algorithm, obtaining theoretical error bounds on the range estimates for given levels of odometric and visual noise, which were verified through experimental data. Our results suggest that looming can be used as a robust, inexpensive range sensor as a complement to sonar.Defense Advanced Research Projects Agency; Office of Naval Research; Navy Research Laboratory (00014-96-1-0772, 00014-95-1-0409

Learning and Using Context on a Humanoid Robot Using Latent Dirichlet Allocation

2014 Joint IEEE International Conferences on Development and Learning and Epigenetic Robotics (ICDL-Epirob), Genoa, Italy, 13-16 October 2014In this work, we model context in terms of a set of concepts grounded in a robot's sensorimotor interactions with the environment. For this end, we treat context as a latent variable in Latent Dirichlet Allocation, which is widely used in computational linguistics for modeling topics in texts. The flexibility of our approach allows many-to-many relationships between objects and contexts, as well as between scenes and contexts. We use a concept web representation of the perceptions of the robot as a basis for context analysis. The detected contexts of the scene can be used for several cognitive problems. Our results demonstrate that the robot can use learned contexts to improve object recognition and planning.Scientific and Technological Research Council of Turkey (TUBiTAK

Learning Context on a Humanoid Robot using Incremental Latent Dirichlet Allocation

In this article, we formalize and model context in terms of a set of concepts grounded in the sensorimotor interactions of a robot. The concepts are modeled as a web using Markov Random Field, inspired from the concept web hypothesis for representing concepts in humans. On this concept web, we treat context as a latent variable of Latent Dirichlet Allocation (LDA), which is a widely-used method in computational linguistics for modeling topics in texts. We extend the standard LDA method in order to make it incremental so that (i) it does not re-learn everything from scratch given new interactions (i.e., it is online) and (ii) it can discover and add a new context into its model when necessary. We demonstrate on the iCub platform that, partly owing to modeling context on top of the concept web, our approach is adaptive, online and robust: It is adaptive and online since it can learn and discover a new context from new interactions. It is robust since it is not affected by irrelevant stimuli and it can discover contexts after a few interactions only. Moreover, we show how to use the context learned in such a model for two important tasks: object recognition and planning.Scientific and Technological Research Council of TurkeyMarie Curie International Outgoing Fellowship titled “Towards Better Robot Manipulation: Improvement through Interaction

A Comparison of Epidural Anesthesia and Lumbar Plexus-Sciatic Nerve Blocks for Knee Surgery

OBJECTIVES: The efficacy of combined lumbar plexus-sciatic nerve blocks was compared to epidural anesthesia in patients undergoing total knee surgery. PATIENTS AND METHODS: The study included 80 American Society of Anesthesiologists (ASA) Physical Status I-III patients (age range 18 to 65) undergoing knee surgery. The patients were randomly divided into one of two groups. Epidural anesthesia was performed in the epidural anesthesia (EA) group (n=40), and the lumbar plexus and sciatic nerves were blockedin the lumbar plexus-sciatic nerve blocks (LPSB) group (n=40). For each patient, onset of sensory and motor block, degree of motor block, sign of sensory block in the contralateral lower limb for the lumbar plexus-sciatic nerve blocks group, success in providing adequate anesthesia, hemodynamic changes, time of first analgesic request, and patient and surgeon satisfaction with the anesthetic technique were recorded. RESULTS: One patient in the epidural anesthesia group and three patients in the lumbar plexus-sciatic nerve blocks group required general anesthesia due to failed block. There were no significant differences between the two groups regarding the success of providing adequate anesthesia. Eight patients in the lumbar plexus-sciatic nerve blocks group developed contralateral spread. The onset of sensory-motor block and the time of the first analgesic request were significantly later in the lumbar plexus-sciatic nerve blocks group than in the epidural anesthesia group. Although there were no significant differences regarding patient satisfaction with the anesthetic technique between the two groups, surgeon satisfaction was significantly higher in the lumbar plexus-sciatic nerve blocks group than in the epidural anesthesia group. CONCLUSION: The lumbar plexus -sciatic nerve blocks provide effective unilateral anesthesia and may offer a beneficial alternative to epidural anesthesia in patients undergoing total knee surgery

A multi-agent framework for load consolidation in logistics

Logistics companies mainly provide land transportation services facing with difficulties in making effective operational decisions. This is especially the case of making load/capacity/route planning and load consolidation where customer orders are generally unpredictable and subject to sudden changes. Classical modelling and decision support systems are mostly insufficient for providing satisfactory solutions in a reasonable time solving such dynamic problems. Agent-based approaches, especially multi-agent paradigms that can be considered as relatively new members of system science and software engineering, are providing effective mechanisms for modelling dynamic systems generally operating under unpredictable environments and having a high degree of complex interactions. It seems that multi-agent paradigms have big potential for handling complex problems in land transportation logistics. Based on this motivation, the paper proposes a multi-agent based framework for load consolidation problems of third-party logistics companies

Evolving aggregation behaviors in a swarm of robots

In this paper, we study aggregation in a swarm of simple robots, called s-bots, having the capability to self-organize and self-assemble to form a robotic system, called a swarm-bot. The aggregation process, observed in many biological systems, is of fundamental importance since it is the prerequisite for other forms of cooperation that involve self-organization and self-assembling. We consider the problem of designing the control system for the swarm-bot using artificial evolution. The results obtained in a simulated 3D environment are presented and analyzed. They show that artificial evolution, exploiting the complex interactions among s-bots and between s-bots and the environment, is able to produce simple but general solutions to the aggregation problem

Relationship between psychosocial status, diabetes mellitus, and left ventricular systolic function in patients with stable multivessel coronary artery disease

Background: Negative emotional conditions contribute to the development of coronary artery disease (CAD). Depression and anxiety are prognostic factors in patients with CAD. The aim of our study was to investigate the association between emotional conditions and left ventricular (LV) systolic functions in CAD. Methods: 168 patients (102 men, 66 women, mean age 66.3 &#177; 9.9 years) with stable angina and multivessel disease (MVD) were included in the study. According to the LV ejection fraction (LVEF) in echocardiography, patients were divided into two groups, the preserved group (LVEF > 50%), and the impaired group (LVEF < 50%). The preserved group consisted of 94 patients and the impaired group consisted of 74 patients. Emotional status was evaluated using the Hamilton Depression (HAM-D), Hamilton Anxiety (HAM-A), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) scores. Results: The prevalence of diabetes mellitus (DM) was significantly higher in the impaired group than in the preserved group (29.8% vs 56.8%, p < 0.01). The HAM-D, HAM-A, BAI and BDI scores were higher in the impaired group compared to the preserved group (HAM-D: 12.1 &#177; 3.3 vs 14.5 &#177; 2.3, p = 0.03; HAM-A: 12.7 &#177; 3.4 vs 14.3 &#177; 2.2, p = 0.01; BAI: 18.6 &#177; &#177; 6.4 vs 22.1 &#177; 6.6, p = 0.01 and BDI: 13.9 &#177; 2.5 vs 17.2 &#177; 2.0, p = 0.002, respectively). In multivariate analysis, BDI scores (odds ratio [OR]: 2.197, < 95% confidence interval [CI] 1.101&#8211;4.387; p = 0.026), HAM-A scores (OR: 1.912, < 95% Cl 1.092&#8211;2.974; p = 0.041) and DM (OR: 2.610, < 95% Cl 1.313&#8211;5.183; p = 0.006) were important risk factors for LV dysfunction in stable patients with MVD. Conclusions: This study demonstrated that emotional status and DM are factors associated with impaired LV systolic function in patients with stable CAD

The effect of gender on response to antithyroid drugs and risk of relapse after discontinuation of the antithyroid drugs in patients with Graves’ hyperthyroidism: a multicentre study

Introduction: The outcome of medical treatment in patients with Graves’ disease (GD) is generally difficult to predict. In this study, we examined the hypothesis that gender may affect the outcome of treatment with antithyroid drugs (ATDs). Material and methods: This is a retrospective multicentre study including 717 (514 female and 203 male) patients with the first episode of GD treated for at least 12 months. Patients were classified as relapse, poorly controlled (several episodes of hyperthyroidism followed by euthyroidism and rarely hypothyroidism, occurring after titration of ATDs), and remission. Results: During the mean follow-up time of 26.75 ± 21.25 months (between 1 and 120 months), 269 (37.5%), 176 (24.5%), and 272 (37.9%) patients experienced a relapse, a poorly controlled disease, and remained in remission, respectively. During the follow-up time, 223 (43.4%) of the female and only 49 (24%) of the male patients remained in remission. Relapse and poorly controlled disease (non-remitting GD) were more common in male compared to female patients with GD (hazard ratio 1.26, 95% CI: 1.03–1.53, p = 0.025). Graves’ disease in male patients tended to relapse earlier, and male patients tended to have larger goiter sizes at diagnosis as well. The smoking habit wasalso significantly more frequent in males compared to female patients with GD. Conclusion: Male patients with GD have a markedly higher frequency of relapse and poorly controlled disease, as compared to female patients. Larger goiter sizes and higher frequency of smoking may contribute to the higher frequency of relapse and poorly controlled disease in male patients.