Direct Image-to-Geometry Registration Using Mobile Sensor Data

Peer reviewedPublisher PD

Recovering 6D Object Pose: A Review and Multi-modal Analysis

A large number of studies analyse object detection and pose estimation at visual level in 2D, discussing the effects of challenges such as occlusion, clutter, texture, etc., on the performances of the methods, which work in the context of RGB modality. Interpreting the depth data, the study in this paper presents thorough multi-modal analyses. It discusses the above-mentioned challenges for full 6D object pose estimation in RGB-D images comparing the performances of several 6D detectors in order to answer the following questions: What is the current position of the computer vision community for maintaining "automation" in robotic manipulation? What next steps should the community take for improving "autonomy" in robotics while handling objects? Our findings include: (i) reasonably accurate results are obtained on textured-objects at varying viewpoints with cluttered backgrounds. (ii) Heavy existence of occlusion and clutter severely affects the detectors, and similar-looking distractors is the biggest challenge in recovering instances' 6D. (iii) Template-based methods and random forest-based learning algorithms underlie object detection and 6D pose estimation. Recent paradigm is to learn deep discriminative feature representations and to adopt CNNs taking RGB images as input. (iv) Depending on the availability of large-scale 6D annotated depth datasets, feature representations can be learnt on these datasets, and then the learnt representations can be customized for the 6D problem

Suris tetrons: possible spectroscopic evidence for four-particle optical excitations of the 2D electron gas

The excitations of a two-dimensional electron gas in quantum wells with intermediate carrier density (~10^{11} cm^{-2}), i.e., between the exciton-trion- and the Fermi-Sea range, are so far poorly understood. We report on an approach to bridge this gap by a magneto-photoluminescence study of modulation-doped (Cd,Mn)Te quantum well structures. Employing their enhanced spin splitting, we analyzed the characteristic magnetic-field behavior of the individual photoluminescence features. Based on these results and earlier findings by other authors, we present a new approach for understanding the optical transitions at intermediate densities in terms of four-particle excitations, the Suris tetrons, which were up to now only predicted theoretically. All characteristic photoluminescence features are attributed to emission from these quasi-particles when attaining different final states.Comment: 12 pages, 3 figure

Uptake of 137Cs by Leafy Vegetables and Grains from Calcareous Soils

Cesium-137 was deposited on Bikini Island at Bikini Atoll in 1954 as a result of nuclear testing and has been transported and cycled in the ecosystem ever since. Atoll soils are of marine origin and are almost pure CaCO{sub 3} with high concentrations of organic matter in the top 40 cm. Data from previous experiments with mature fruit trees show very high transfer factors (TF's), [Bq g{sup -1} plant/ Bq g{sup -1} soil, both in dry weight] into fruits from atoll calcareous soil. These TF's are much higher than reported for continental, silica-based soils. In this report TF's for 5 types of leafy vegetable crops and 2 types of grain crops are provided for use in predictive dose assessments and for comparison with other data from other investigators working with other types of soil in the IAEA CRP ''The Classification of Soil Systems on the Basis of Transfer Factors of Radionuclides from Soil to Reference Plants''. Transfer factors for plants grown on calcareous soil are again very high relative to clay-containing soils and range from 23 to 39 for grain crops and 21 to 113 for leafy vegetables. Results from these experiments, in this unique, high pH, high organic content, low potassium (K) soil, provide a boundary condition for models relating soil properties to TF

Adenosine Type 1 (A ) Receptors Mediate Protection Against Myocardial 1 Infarction Produced by Chronic, Intermittent Ingestion of Ethanol in Dogs

Background: Chronic consumption of small amounts of ethanol protects myocardium from ischemic injury. We tested the hypothesis that adenosine type 1 (A1) receptors mediate these beneficial effects. Methods: Dogs (n=37) were fed with ethanol (1.5 g/kg) or water mixed with dry food twice per day for 12 weeks, fasted overnight before experimentation, and instrumented for measurement of hemodynamics. Dogs received intravenous drug vehicle (50% polyethylene glycol in 0.1 N sodium hydroxide and 0.9% saline over 15 min) or the selective A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 0.8 mg/kg over 15 min) and were subjected to a 60 min coronary artery occlusion followed by 3 h of reperfusion. Myocardial infarct size and transmural coronary collateral blood flow were measured with triphenyltetrazolium chloride staining and radioactive microspheres, respectively. Results: The area at risk (AAR) for infarction was similar between groups. Pretreatment with ethanol significantly reduced infarct size to 13±2% (n=7) of the AAR as compared to control experiments (26±2%; n=7). DPCPX abolished the protective effects of ethanol pretreatment (30±3%; n=7) but had no effect in dogs that did not receive ethanol (25±2%; n=7). No differences in transmural coronary collateral blood flow were observed between groups. Conclusions: The present findings indicate that chronic ingestion of small amounts of ethanol produces myocardial protection that persists after the discontinuation of ethanol. The results indicate that A1 receptors mediate ethanol-induced preconditioning in dogs independent of alterations in systemic hemodynamics or coronary collateral blood flow

Influence of Isoflurane on Left Atrial Function in Dogs With Pacing-Induced Cardiomyopathy: Evaluation With Pressure-Volume Relationships

Objective The actions of volatile anesthetics on left ventricular (LV) function in normal and failing hearts have been previously evaluated, but the effects of these agents on left atrial (LA) function in the presence of LV dysfunction are unknown. The hypothesis was tested that isoflurane alters LA mechanics evaluated with pressure-volume relations. Design Prospective. Setting Laboratory. Participants Barbiturate-anesthetized dogs (n = 8) were instrumented for measurement of aortic, LA, and LV pressures (micromanometers), and LA volume (epicardial orthogonal sonomicrometers) after 3 weeks of rapid ventricular pacing (220 beats/min). Interventions LA myocardial contractility (Ees) was assessed with end-systolic pressure-volume relations. LA stroke work and reservoir function were assessed by A and V loop area, respectively, from the steady-state pressure-volume diagram. LA-LV coupling was determined by the ratio of Ees to LV elastance (ELV). Dogs received 0.6, 0.9, and 1.2 minimum alveolar concentration isoflurane in a random manner, and LA function was determined after a 20-minute equilibration at each dose. Measurements and main results Isoflurane significantly (p \u3c 0.05) decreased heart rate, mean arterial pressure, LV end-systolic pressure, and LV +dP/dtmax. Isoflurane produced dose-related reductions in Ees and Ees/ELV. Declines in LA stroke work, emptying fraction, reservoir volume, V loop area, and the active LA contribution to LV filling also occurred. Conclusions The results indicate that isoflurane depresses LA myocardial contractility, impairs LA-LV coupling, and reduces active LA contribution to LV filling in dogs with pacing-induced cardiomyopathy. The impact of isoflurane on LA function in the presence of LV dysfunction has profound effects on cardiac performance

Aloha Undergraduates: Development and Application of Local & Indigenous Topics into an Undergraduate Public Health Curriculum

As public health education expands to include undergraduate students, it is important to include discussion of local public health topics and issues to provide a sense of place to the educational experience. Inclusion of Native Hawaiian and indigenous issues and perspectives is also an established priority of the University of Hawai‘i system. To address both needs, a required course was created during development of a new Bachelor of Arts (BA) public health program at the University of Hawai‘i at Mānoa to specifically focus on discussion of local and indigenous public health topics of interest. Public Health Issues in Hawai‘i is an introductory course included early in the recommended undergraduate curriculum and emphasizes the application of public health skills and principles to local issues (e.g., state-level legislative awareness and local sustainability topics). The Public Health Issues in Hawai‘i course further challenges students to recognize public health practice in their daily activities, and encourages them to become actively engaged in local community issues early in their public health educational careers. Among multiple advantages, improved awareness of local health challenges and early connections to community members and organizations have been instrumental in actively engaging local students in their education, and has also proved beneficial for students participating in required undergraduate applied learning capstone experiences and entry-level public health careers following graduation. Here we present insights into course development, articulation with broader program curricula, and successes and challenges in the past 4 years of implementation and instruction