| 1. |
- Zhang, Ri-Chao, et al.
(författare)
-
Microplasma Processed Ultrathin Boron Nitride Nanosheets for Polymer Nanocomposites with Enhanced Thermal Transport Performance
- 2016
-
Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 8:21, s. 13567-13572
-
Tidskriftsartikel (refereegranskat)abstract
- This Research Article reports on the enhancement of the thermal transport properties of nanocomposite materials containing hexagonal boron nitride in poly(vinyl alcohol) through room-temperature atmospheric pressure direct-current microplasma processing. Results show that the microplasma treatment leads to exfoliation of the hexagonal boron nitride in isopropyl alcohol, reducing the number of stacks from amp;gt;30 to a few or single layers. The thermal diffusivity of the resulting nanocomposites reaches 8.5 mm(2) s(-1) times greater than blank poly(vinyl alcohol) and twice that of nanocomposites containing nonplasma treated boron nitride nanosheets. From TEM analysis, we observe much less aggregation Of the nanosheets after plasma processing along with indications of an amorphous carbon interfacial layer, which may contribute to stable dispersion of boron nitride nanosheets in the resulting plasma treated colloids.
|
|
| 2. |
- Connolly, Stuart J, et al.
(författare)
-
Dronedarone in High-Risk Permanent Atrial Fibrillation
- 2011
-
Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 365:24, s. 2268-2276
-
Tidskriftsartikel (refereegranskat)abstract
- Background Dronedarone restores sinus rhythm and reduces hospitalization or death in intermittent atrial fibrillation. It also lowers heart rate and blood pressure and has antiadrenergic and potential ventricular anti-arrhythmic effects. We hypothesized that dronedarone would reduce major vascular events in high-risk permanent atrial fibrillation. Methods We assigned patients who were at least 65 years of age with at least a 6-month history of permanent atrial fibrillation and risk factors for major vascular events to receive dronedarone or placebo. The first coprimary outcome was stroke, myocardial infarction, systemic embolism, or death from cardiovascular causes. The second coprimary outcome was unplanned hospitalization for a cardiovascular cause or death. Results After the enrollment of 3236 patients, the study was stopped for safety reasons. The first coprimary outcome occurred in 43 patients receiving dronedarone and 19 receiving placebo (hazard ratio, 2.29; 95% confidence interval [CI], 1.34 to 3.94; P=0.002). There were 21 deaths from cardiovascular causes in the dronedarone group and 10 in the placebo group (hazard ratio, 2.11; 95% CI, 1.00 to 4.49; P=0.046), including death from arrhythmia in 13 patients and 4 patients, respectively (hazard ratio, 3.26; 95% CI, 1.06 to 10.00; P=0.03). Stroke occurred in 23 patients in the dronedarone group and 10 in the placebo group (hazard ratio, 2.32; 95% CI, 1.11 to 4.88; P=0.02). Hospitalization for heart failure occurred in 43 patients in the dronedarone group and 24 in the placebo group (hazard ratio, 1.81; 95% CI, 1.10 to 2.99; P=0.02). Conclusions Dronedarone increased rates of heart failure, stroke, and death from cardiovascular causes in patients with permanent atrial fibrillation who were at risk for major vascular events. Our data show that this drug should not be used in such patients.
|
|
| 3. |
- Cowper, Patricia A., et al.
(författare)
-
Economic Analysis of Apixaban Therapy for Patients With Atrial Fibrillation From a US Perspective : Results From the ARISTOTLE Randomized Clinical Trial
- 2017
-
Ingår i: JAMA cardiology. - : American Medical Association (AMA). - 2380-6583 .- 2380-6591. ; 2:5, s. 525-534
-
Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE The Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial reported that apixaban therapy was superior to warfarin therapy in preventing stroke and all-cause death while causing significantly fewer major bleeds. To establish the value proposition of substituting apixiban therapy for warfarin therapy in patients with atrial fibrillation, we performed a cost-effectiveness analysis using patient-level data from the ARISTOTLE trial.OBJECTIVE To assess the cost and cost-effectiveness of apixaban therapy compared with warfarin therapy in patients with atrial fibrillation from the perspective of the US health care system.DESIGN, SETTING, AND PARTICIPANTS This economic analysis uses patient-level resource use and clinical data collected in the ARISTOTLE trial, a multinational randomized clinical trial that observed 18 201 patients (3417 US patients) for a median of 1.8 years between 2006 and 2011.INTERVENTIONS Apixaban therapy vs warfarin therapy.MAIN OUTCOMES AND MEASURES Within-trial resource use and costwere compared between treatments, using externally derived US cost weights. Life expectancies for US patients were estimated according to their baseline risk and treatment using time-based and age-based survival models developed using the overall ARISTOTLE population. Quality-of-life adjustment factors were obtained from external sources. Cost-effectiveness (incremental cost per quality-adjusted life-year gained) was evaluated from a US perspective, and extensive sensitivity analyses were performed.RESULTS Of the 3417 US patients enrolled in ARISTOTLE, the mean (SD) age was 71 (10) years; 2329 (68.2%) were male and 3264 (95.5%) were white. After 2 years of anticoagulation therapy, health care costs (excluding the study drug) of patients treated with apixaban therapy and warfarin therapy were not statistically different (difference, -$ 60; 95% CI, -$ 2728 to $ 2608). Life expectancy, modeled from ARISTOTLE outcomes, was significantly longer with apixaban therapy vs warfarin therapy (7.94 vs 7.54 quality-adjusted life years). The incremental cost, including cost of anticoagulant and monitoring, of achieving these benefits was within accepted US norms ($ 53 925 per quality-adjusted life year, with 98% likelihood of meeting a $ 100 000 willingness-to-pay threshold). Results were generally consistent when model assumptions were varied, with lifetime cost-effectiveness most affected by the price of apixaban and the time horizon.CONCLUSIONS AND RELEVANCE Apixaban therapy for ARISTOTLE-eligible patients with atrial fibrillation provides clinical benefits at an incremental cost that represents reasonable value for money judged using US benchmarks for cost-effectiveness.
|
|
| 4. |
- Flaker, Greg, et al.
(författare)
-
Amiodarone, Anticoagulation, and Clinical Events in Patients With Atrial Fibrillation Insights From the ARISTOTLE Trial
- 2014
-
Ingår i: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097 .- 1558-3597. ; 64:15, s. 1541-1550
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Amiodarone is an effective medication in preventing atrial fibrillation (AF), but it interferes with the metabolism of warfarin. OBJECTIVES This study sought to examine the association of major thrombotic clinical events and bleeding with the use of amiodarone in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial. METHODS Baseline characteristics of patients who received amiodarone at randomization were compared with those who did not receive amiodarone. The interaction between randomized treatment and amiodarone was tested using a Cox model, with main effects for randomized treatment and amiodarone and their interaction. Matching on the basis of a propensity score was used to compare patients who received and who did not receive amiodarone at the time of randomization. RESULTS In ARISTOTLE, 2,051 (11.4%) patients received amiodarone at randomization. Patients on warfarin and amiodarone had time in the therapeutic range that was lower than patients not on amiodarone (56.5% vs. 63.0%; p < 0.0001). More amiodarone-treated patients had a stroke or a systemic embolism (1.58%/year vs. 1.19%/year; adjusted hazard ratio [HR]: 1.47, 95% confidence interval [CI]: 1.03 to 2.10; p = 0.0322). Overall mortality and major bleeding rates were elevated, but were not significantly different in amiodarone-treated patients and patients not on amiodarone. When comparing apixaban with warfarin, patients who received amiodarone had a stroke or a systemic embolism rate of 1.24%/year versus 1.85%/year (HR: 0.68, 95% CI: 0.40 to 1.15), death of 4.15%/year versus 5.65%/year (HR: 0.74, 95% CI: 0.55 to 0.98), and major bleeding of 1.86%/year versus 3.06%/year (HR: 0.61, 95% CI: 0.39 to 0.96). In patients who did not receive amiodarone, the stroke or systemic embolism rate was 1.29%/year versus 1.57%/year (HR: 0.82, 95% CI: 0.68 to 1.00), death was 3.43%/year versus 3.68%/year (HR: 0.93, 95% CI: 0.83 to 1.05), and major bleeding was 2.18%/year versus 3.03%/year (HR: 0.72, 95% CI: 0.62 to 0.84). The interaction p values for amiodarone use by apixaban treatment effects were not significant. CONCLUSIONS Amiodarone use was associated with significantly increased stroke and systemic embolism risk and a lower time in the therapeutic range when used with warfarin. Apixaban consistently reduced the rate of stroke and systemic embolism, death, and major bleeding compared with warfarin in amiodarone-treated patients and patients who were not on amiodarone.
|
|
| 5. |
- Gálvez López, Dorian, et al.
(författare)
-
Hybrid Laser and Vision Based Object Search and Localization
- 2008
-
Ingår i: 2008 IEEE International Conference on Robotics and Automation. - 9781424416462 ; , s. 2636-2643
-
Konferensbidrag (refereegranskat)abstract
- We describe a method for an autonomous robot to efficiently locate one or more distinct objects in a realistic environment using monocular vision. We demonstrate how to efficiently subdivide acquired images into interest regions for the robot to zoom in on, using receptive field cooccurrence histograms. Objects are recognized through SIFT feature matching and the positions of the objects are estimated. Assuming a 2D map of the robot's surroundings and a set of navigation nodes between which it is free to move, we show how to compute an efficient sensing plan that allows the robot's camera to cover the environment, while obeying restrictions on the different objects' maximum and minimum viewing distances. The approach has been implemented on a real robotic system and results are presented showing its practicability and the quality of the position estimates obtained.
|
|
| 6. |
- Garcia, David, et al.
(författare)
-
Management and clinical outcomes in patients treated with apixaban versus warfarin undergoing procedures
- 2014
-
Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 124:25, s. 3692-3698
-
Tidskriftsartikel (refereegranskat)abstract
- Using data from ARISTOTLE, we describe the periprocedural management of anticoagulation and rates of subsequent clinical outcomes among patients chronically anticoagulated with warfarin or apixaban. We recorded whether (and for how long) anticoagulant therapy was interrupted pre-procedure; whether bridging therapy was used; and the proportion of patients who experienced important clinical outcomes during the 30 days post-procedure. Of 10,674 procedures performed during follow-up in 5924 patients, 9260 were included in this analysis. Anticoagulant treatment was not interrupted pre-procedure 37.5% of the time. During the 30 days post-procedure, stroke or systemic embolism occurred after 16/4624 (0.35%) procedures among apixaban-treated patients and 26/4530 (0.57%) procedures among warfarin-treated patients (OR 0.601; 95% CI 0.322–1.120). Major bleeding occurred in 74/4560 (1.62%) procedures in the apixaban arm and 86/4454 (1.93%) in the warfarin arm (OR 0.846; 95% CI 0.614–1.166). The risk of death was similar with apixaban (54/4624 [1.17%]) and warfarin (49/4530 [1.08%]) (OR 1.082; 95% CI 0.733–1.598). Among patients in ARISTOTLE, the 30-day post-procedure stroke, death, and major bleeding rates were low and similar in apixaban- and warfarin-treated patients, regardless of whether anticoagulation was stopped beforehand. Our findings suggest that many patients on chronic anticoagulation can safely undergo procedures; some will not require a pre-procedure interruption of anticoagulation. ARISTOTLE ClinicalTrials.gov number (NCT00412984).
|
|
| 7. |
- Holst, Anders G., et al.
(författare)
-
Inhibition of the KCa2 potassium channel in atrial fibrillation: a randomized phase 2 trial
- 2023
-
Ingår i: Nature Medicine. - 1078-8956 .- 1546-170X.
-
Tidskriftsartikel (refereegranskat)abstract
- Existing antiarrhythmic drugs to treat atrial fibrillation (AF) have incomplete efficacy, contraindications and adverse effects, including proarrhythmia. AP30663, an inhibitor of the KCa2 channel, has demonstrated AF efficacy in animals; however, its efficacy in humans with AF is unknown. Here we conducted a phase 2 trial in which patients with a current episode of AF lasting for 7 days or less were randomized to receive an intravenous infusion of 3 or 5 mg kg−1 AP30663 or placebo. The trial was prematurely discontinued because of slow enrollment during the coronavirus disease 2019 pandemic. The primary endpoint of the trial was cardioversion from AF to sinus rhythm within 90 min from the start of the infusion, analyzed with Bayesian statistics. Among 59 patients randomized and included in the efficacy analyses, the primary endpoint occurred in 42% (5 of 12), 55% (12 of 22) and 0% (0 of 25) of patients treated with 3 mg kg−1 AP30663, 5 mg kg−1 AP30663 or placebo, respectively. Both doses demonstrated more than 99.9% probability of superiority over placebo, surpassing the prespecified 95% threshold. The mean time to cardioversion, a secondary endpoint, was 47 (s.d. = 23) and 41 (s.d. = 24) minutes for 3 mg kg−1 and 5 mg kg−1 AP30663, respectively. AP30663 caused a transient increase in the QTcF interval, with a maximum mean effect of 37.7 ms for the 5 mg kg−1 dose. For both dose groups, no ventricular arrhythmias occurred and adverse event rates were comparable to the placebo group. AP30663 demonstrated AF cardioversion efficacy in patients with recent-onset AF episodes. KCa2 channel inhibition may be an attractive mechanism for rhythm control of AF that should be studied further in randomized trials. ClinicalTrials.gov registration: NCT04571385 .
|
|
| 8. |
- Kirchhof, Paulus, et al.
(författare)
-
Comprehensive risk reduction in patients with atrial fibrillation : emerging diagnostic and therapeutic options - a report from the 3rd Atrial Fibrillation Competence NETwork/European Heart Rhythm Association consensus conference
- 2012
-
Ingår i: Europace. - : Oxford University Press (OUP). - 1099-5129 .- 1532-2092. ; 14:1, s. 8-27
-
Forskningsöversikt (refereegranskat)abstract
- While management of atrial fibrillation (AF) patients is improved by guideline-conform application of anticoagulant therapy, rate control, rhythm control, and therapy of accompanying heart disease, the morbidity and mortality associated with AF remain unacceptably high. This paper describes the proceedings of the 3rd Atrial Fibrillation NETwork (AFNET)/European Heart Rhythm Association (EHRA) consensus conference that convened over 60 scientists and representatives from industry to jointly discuss emerging therapeutic and diagnostic improvements to achieve better management of AF patients. The paper covers four chapters: (i) risk factors and risk markers for AF; (ii) pathophysiological classification of AF; (iii) relevance of monitored AF duration for AF-related outcomes; and (iv) perspectives and needs for implementing better antithrombotic therapy. Relevant published literature for each section is covered, and suggestions for the improvement of management in each area are put forward. Combined, the propositions formulate a perspective to implement comprehensive management in AF.
|
|
| 9. |
- Larson, Greger, et al.
(författare)
-
Current perspectives and the future of domestication studies
- 2014
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 111:17, s. 6139-6146
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- It is difficult to overstate the cultural and biological impacts that the domestication of plants and animals has had on our species. Fundamental questions regarding where, when, and how many times domestication took place have been of primary interest within a wide range of academic disciplines. Within the last two decades, the advent of new archaeological and genetic techniques has revolutionized our understanding of the pattern and process of domestication and agricultural origins that led to our modern way of life. In the spring of 2011, 25 scholars with a central interest in domestication representing the fields of genetics, archaeobotany, zooarchaeology, geoarchaeology, and archaeology met at the National Evolutionary Synthesis Center to discuss recent domestication research progress and identify challenges for the future. In this introduction to the resulting Special Feature, we present the state of the art in the field by discussing what is known about the spatial and temporal patterns of domestication, and controversies surrounding the speed, intentionality, and evolutionary aspects of the domestication process. We then highlight three key challenges for future research. We conclude by arguing that although recent progress has been impressive, the next decade will yield even more substantial insights not only into how domestication took place, but also when and where it did, and where and why it did not.
|
|
| 10. |
- Lopes, Renato D., et al.
(författare)
-
Efficacy and safety of apixaban compared with warfarin according to patient risk of stroke and of bleeding in atrial fibrillation : a secondary analysis of a randomised controlled trial
- 2012
-
Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 380:9855, s. 1749-1758
-
Tidskriftsartikel (refereegranskat)abstract
- Background The Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial showed that apixaban is better than warfarin at prevention of stroke or systemic embolism, causes less bleeding, and results in lower mortality. We assessed in this trial's participants how results differed according to patients' CHADS(2), CHA(2)DS(2)VASc, and HAS-BLED scores, used to predict the risk of stroke and bleeding. Methods ARISTOTLE was a double-blind, randomised trial that enrolled 18 201 patients with atrial fibrillation in 39 countries. Patients were randomly assigned apixaban 5 mg twice daily (n=9120) or warfarin (target international normalised ratio 2.0-3.0; n=9081). The primary endpoint was stroke or systemic embolism. The primary safety outcome was major bleeding. We calculated CHADS(2), CHA(2)DS(2)VASc, and HAS-BLED scores of patients at randomisation. Efficacy analyses were by intention to treat, and safety analyses were of the population who received the study drug. ARISTOTLE is registered with ClinicalTrials.gov, number NCT00412984. Findings Apixaban significantly reduced stroke or systemic embolism with no evidence of a differential effect by risk of stroke (CHADS(2) 1, 2, or >= 3, p for interaction=0.4457; or CHA(2)DS(2)VASc 1, 2, or >= 3, p for interaction=0.1210) or bleeding (HAS-BLED 0-1, 2, or >= 3, p for interaction=0.9422). Patients who received apixaban had lower rates of major bleeding than did those who received warfarin, with no difference across all score categories (CHADS(2), p for interaction=0.4018; CHA(2)DS(2)VASc, p for interaction=0.2059; HAS-BLED, p for interaction=0.7127). The relative risk reduction in intracranial bleeding tended to be greater in patients with HAS-BLED scores of 3 or higher (hazard ratio [HR] 0.22, 95% CI 0.10-0.48) than in those with HAS-BLED scores of 0-1 (HR 0.66, 0.39-1.12; p for interaction=0.0604). Interpretation Because apixaban has benefits over warfarin that are consistent across patient risk of stroke and bleeding as assessed by the CHADS(2), CHA(2)DS(2)VASc, and HAS-BLED scores, these scores might be less relevant when used to tailor apixaban treatment to individual patients than they are for warfarin. Further improvement in risk stratification for both stroke and bleeding is needed, particularly for patients with atrial fibrillation at low risk for these events.
|
|
| 11. |
- Marchant, Rob, et al.
(författare)
-
Drivers and trajectories of land cover change in East Africa : Human and environmental interactions from 6000 years ago to present
- 2018
-
Ingår i: Earth-Science Reviews. - : Elsevier. - 0012-8252 .- 1872-6828. ; 178, s. 322-378
-
Tidskriftsartikel (refereegranskat)abstract
- East African landscapes today are the result of the cumulative effects of climate and land-use change over millennial timescales. In this review, we compile archaeological and palaeoenvironmental data from East Africa to document land-cover change, and environmental, subsistence and land-use transitions, over the past 6000 years. Throughout East Africa there have been a series of relatively rapid and high-magnitude environmental shifts characterised by changing hydrological budgets during the mid- to late Holocene. For example, pronounced environmental shifts that manifested as a marked change in the rainfall amount or seasonality and subsequent hydrological budget throughout East Africa occurred around 4000, 800 and 300 radiocarbon years before present (yr BP). The past 6000 years have also seen numerous shifts in human interactions with East African ecologies. From the mid-Holocene, land use has both diversified and increased exponentially, this has been associated with the arrival of new subsistence systems, crops, migrants and technologies, all giving rise to a sequence of significant phases of land-cover change. The first large-scale human influences began to occur around 4000 yr BP, associated with the introduction of domesticated livestock and the expansion of pastoral communities. The first widespread and intensive forest clearances were associated with the arrival of iron-using early farming communities around 2500 yr BP, particularly in productive and easily-cleared mid-altitudinal areas. Extensive and pervasive land-cover change has been associated with population growth, immigration and movement of people. The expansion of trading routes between the interior and the coast, starting around 1300 years ago and intensifying in the eighteenth and nineteenth centuries CE, was one such process. These caravan routes possibly acted as conduits for spreading New World crops such as maize (Zea mays), tobacco (Nicotiana spp.) and tomatoes (Solanum lycopersicum), although the processes and timings of their introductions remains poorly documented. The introduction of southeast Asian domesticates, especially banana (Musa spp.), rice (Oryza spp.), taro (Colocasia esculenta), and chicken (Gallus gallus), via transoceanic biological transfers around and across the Indian Ocean, from at least around 1300 yr BP, and potentially significantly earlier, also had profound social and ecological consequences across parts of the region. Through an interdisciplinary synthesis of information and metadatasets, we explore the different drivers and directions of changes in land-cover, and the associated environmental histories and interactions with various cultures, technologies, and subsistence strategies through time and across space in East Africa. This review suggests topics for targeted future research that focus on areas and/or time periods where our understanding of the interactions between people, the environment and land-cover change are most contentious and/or poorly resolved. The review also offers a perspective on how knowledge of regional land-use change can be used to inform and provide perspectives on contemporary issues such as climate and ecosystem change models, conservation strategies, and the achievement of nature-based solutions for development purposes.
|
|
| 12. |
- Robinson, Victoria M, et al.
(författare)
-
Results of a curtailed randomized controlled trial, evaluating the efficacy and safety of azimilide in patients with implantable cardioverter-defibrillators : The SHIELD-2 trial
- 2017
-
Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 185, s. 43-51
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Frequent hospital attendances in patients with implantable cardioverter-defibrillators (ICDs) result in significant morbidity and health care costs. Current drugs to reduce ICD shocks and hospital visits have limited efficacy and considerable toxicity. We evaluated the efficacy and safety of azimilide, a novel oral class III antiarrhythmic, for use in ICD patients.METHODS: A total of 240 patients were enrolled in a prospective, randomized, double-blind, placebo-controlled trial to evaluate the effect of oral azimilide 75 mg daily in ICD patients with previously documented ventricular tachycardia or ventricular fibrillation, and a left ventricular ejection fraction ≤40%. The primary outcome metric was the adjudicated time-to-first unplanned cardiovascular (CV) hospitalization, or CV emergency department (ED) visit, or CV death. The trial was prematurely discontinued due to withdrawal of study sponsorship.RESULTS: Azimilide demonstrated numerical but statistically nonsignificant reductions in the primary composite outcome (odds ratio [OR] 0.79, 95% CI 0.44-1.44), unplanned CV hospitalizations (OR 0.75, 95% CI 0.41-1.38), ED visits (OR 0.68, 95% CI 0.35-1.31), and all-cause shocks (OR 0.58, 95% CI 0.32-1.05). The incidence of adverse events was lower in the azimilide group. Neutropenia was not observed (absolute neutrophil count <1000 μ/L), and there was one possible torsade de pointes case that led to a successful ICD discharge.CONCLUSION: The SHIELD-2 trial was statistically underpowered due to early trial termination and did not meet its primary objective. Despite this limitation, azimilide showed promise as a safe and effective drug in reducing all-cause shocks, unplanned hospitalizations, and ED visits in ICD patients.
|
|
| 13. |
- Sjöö, Kristoffer, et al.
(författare)
-
Object Search and Localization for an Indoor Mobile Robot
- 2009
-
Ingår i: Journal of Computing and Information Technology. - : Faculty of Electrical Engineering and Computing, Univ. of Zagreb. - 1330-1136 .- 1846-3908. ; 17:1, s. 67-80
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper we present a method for search and localization of objects with a mobile robot using a monocular camera with zoom capabilities. We show how to overcome the limitations of low resolution images in object recognition by utilizing a combination of an attention mechanism and zooming as the first steps in the recognition process. The attention mechanism is based on receptive field cooccurrence histograms and the object recognition on SIFT feature matching. We present two methods for estimating the distance to the objects which serve both as the input to the control of the zoom and the final object localization. Through extensive experiments in a realistic environment, we highlight the strengths and weaknesses of both methods. To evaluate the usefulness of the method we also present results from experiments with an integrated system where a global sensing plan is generated based on view planning to let the camera cover the space on a per room basis.
|
|
