1,472 research outputs found
Active End-Effector Pose Selection for Tactile Object Recognition through Monte Carlo Tree Search
This paper considers the problem of active object recognition using touch
only. The focus is on adaptively selecting a sequence of wrist poses that
achieves accurate recognition by enclosure grasps. It seeks to minimize the
number of touches and maximize recognition confidence. The actions are
formulated as wrist poses relative to each other, making the algorithm
independent of absolute workspace coordinates. The optimal sequence is
approximated by Monte Carlo tree search. We demonstrate results in a physics
engine and on a real robot. In the physics engine, most object instances were
recognized in at most 16 grasps. On a real robot, our method recognized objects
in 2--9 grasps and outperformed a greedy baseline.Comment: Accepted to International Conference on Intelligent Robots and
Systems (IROS) 201
Active End-Effector Pose Selection for Tactile Object Recognition through Monte Carlo Tree Search
This paper considers the problem of active object recognition using touch
only. The focus is on adaptively selecting a sequence of wrist poses that
achieves accurate recognition by enclosure grasps. It seeks to minimize the
number of touches and maximize recognition confidence. The actions are
formulated as wrist poses relative to each other, making the algorithm
independent of absolute workspace coordinates. The optimal sequence is
approximated by Monte Carlo tree search. We demonstrate results in a physics
engine and on a real robot. In the physics engine, most object instances were
recognized in at most 16 grasps. On a real robot, our method recognized objects
in 2--9 grasps and outperformed a greedy baseline.Comment: Accepted to International Conference on Intelligent Robots and
Systems (IROS) 201
Joint estimation and localization in sensor networks
This paper addresses the problem of collaborative tracking of dynamic targets in wireless sensor networks. A novel distributed linear estimator, which is a version of a distributed Kalman filter, is derived. We prove that the filter is mean square consistent in the case of static target estimation. When large sensor networks are deployed, it is common that the sensors do not have good knowledge of their locations, which affects the target estimation procedure. Unlike most existing approaches for target tracking, we investigate the performance of our filter when the sensor poses need to be estimated by an auxiliary localization procedure. The sensors are localized via a distributed Jacobi algorithm from noisy relative measurements. We prove strong convergence guarantees for the localization method and in turn for the joint localization and target estimation approach. The performance of our algorithms is demonstrated in simulation on environmental monitoring and target tracking tasks
Joint Estimation and Localization in Sensor Networks
This paper addresses the problem of collaborative tracking of dynamic targets
in wireless sensor networks. A novel distributed linear estimator, which is a
version of a distributed Kalman filter, is derived. We prove that the filter is
mean square consistent in the case of static target estimation. When large
sensor networks are deployed, it is common that the sensors do not have good
knowledge of their locations, which affects the target estimation procedure.
Unlike most existing approaches for target tracking, we investigate the
performance of our filter when the sensor poses need to be estimated by an
auxiliary localization procedure. The sensors are localized via a distributed
Jacobi algorithm from noisy relative measurements. We prove strong convergence
guarantees for the localization method and in turn for the joint localization
and target estimation approach. The performance of our algorithms is
demonstrated in simulation on environmental monitoring and target tracking
tasks.Comment: 9 pages (two-column); 5 figures; Manuscript submitted to the 2014
IEEE Conference on Decision and Control (CDC
Group Comparisons on Cognitive Attributes Using the Least Squares Distance Model of Cognitive Diagnosis
2010 Mathematics Subject Classification: 62P15.As the cognitive operations are hypothesized according to a cognitive theory in the context of a study, they are latent (hidden) in nature and cannot be measured and scored directly from the test. The least squares distance model (LSDM) of cognitive diagnosis uses estimates of the item parameters under a specific item-response theory (IRT) model to provide estimates of the probability of a person to process correctly any cognitive attribute given the personβs location on the IRT logit scale. In this paper a methodology for comparing two (or more) groups of individuals, according to their performance on a given set of cognitive attributes is presented
EthnopharmacologyβA Bibliometric Analysis of a Field of Research Meandering Between Medicine and Food Science?
BACKGROUND:
The research into bioactive natural products of medicinal plants has a long tradition, but ethnopharmacology as a well-defined field of research has a relatively short history, only dating back 50 years.
AIMS: With the fast development of this field and its global importance especially in the fast developing economies of Asia it is timely to assess the most influential articles (as measured by citations) and to identify important drivers and research trends in this field.
METHODS: Scopus was searched to identify relevant articles which were assessed by all three authors. The 100 most cited articles were identified and analyzed. Bibliometric software (VOSviewer) was utilized to supplement the analysis and to generate a term map that visualized the citation patterns of the 100 articles containing different terms.
RESULTS: Forty-four of the 100 articles are reviews. On average, each of the 100 articles had 632 citations and since publication was cited 43 times annually. The four core journals were Journal of Ethnopharmacology (n = 17), Food Chemistry (n = 7), Life Sciences (n = 5), and Journal of Agricultural and Food Chemistry (n = 4). Anti-oxidant effects appeared to be a recurring and highly cited topic, whereas the links into drug discovery and neuropharmacology seemed to be less strong. Numerous medicinal plants and functional foods were the foci of research, and the foci shifted when comparing pre-2000 and post-2000 publications (with the later involving a broader spectrum of plants and foods and a wider range of biological effects). Contributions largely came from Asia, and also from the Americas, Africa, and Oceania, besides Europe.
CONCLUSIONS: We have identified and analyzed the 100 most-cited articles in ethnopharmacology. Within 50 years the field has gained a profile and while conventionally often linked to βtraditional knowledge,β drug discovery and some areas of pharmacology, this analysis highlights its emerging importance in the context of disease prevention (food science), but also the development of research driven by the needs and interests of the fast developing economies most notably of Asia
Optical Coherent Tomography changes in retinal nerve fiber layer and ganglion cell complex in different stages of open-angle glaucoma
Π¦Π΅Π»: ΠΠ° ΡΠ΅ ΠΎΡΠ΅Π½ΡΡ ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²Π΅Π½ΠΈΡΠ΅ ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π»ΠΈ: Π³Π°Π½Π³Π»ΠΈΠΉΠ½ΠΎ-ΠΊΠ»Π΅ΡΡΡΠ΅Π½ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡ (GCC) ΠΈ ΠΏΠ΅ΡΠΈΠΏΠ°ΠΏΠΈΠ»Π°ΡΠ½ΠΈΡ Π½Π΅Π²ΡΠΎΡΠΈΠ±ΡΠΈΠ»Π΅ΡΠ΅Π½ ΡΠ»ΠΎΠΉ (RNFL ), ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈ Ρ ΠΎΠΏΡΠΈΡΠ½Π° ΠΊΠΎΡ
Π΅ΡΠ΅Π½ΡΠ½Π° ΡΠΎΠΌΠΎΠ³ΡΠ°ΡΠΈΡ (ΠΠ‘Π’) ΠΏΡΠΈ ΡΠ°Π·Π»ΠΈΡΠ½ΠΈ ΡΡΠ°Π΄ΠΈΠΈ Π½Π° ΠΎΡΠΊΡΠΈΡΠΎΡΠ³ΡΠ»Π½Π° Π³Π»Π°ΡΠΊΠΎΠΌΠ°.ΠΠ΅ΡΠΎΠ΄ΠΈ: ΠΠΎΡΡΠ΅Π΄ΡΡΠ²ΠΎΠΌ RTVue-100 (Optovue Inc, Fremont, Π‘Π) ΡΠ° ΠΈΠ·ΡΠ»Π΅Π΄Π²Π°Π½ΠΈ 60 ΠΎΡΠΈ Π½Π° Π4 Π±ΠΎΠ»Π½ΠΈ Ρ ΠΎΡΠΊΡΠΈΡΠΎΡΠ³ΡΠ»Π½Π° Π³Π»Π°ΡΠΊΠΎΠΌΠ° ΠΈ 60 ΠΎΡΠΈ Π½Π° Π0 Π·Π΄ΡΠ°Π²ΠΈ Π»ΠΈΡΠ°. Π Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡ ΠΎΡ ΠΏΠ΅ΡΠΈΠΌΠ΅ΡΡΠΈΡΠ½ΠΈΡΠ΅ Π³Π»ΠΎΠ±Π°Π»Π½ΠΈ ΠΈΠ½Π΄Π΅ΠΊΡΠΈ MD ΠΈ PSD (Πumphrey analyzer), Π³Π»Π°ΡΠΊΠΎΠΌΠ½ΠΈΡΠ΅ ΠΎΡΠΈ ΡΠ° ΡΠ°Π·Π΄Π΅Π»Π΅Π½ΠΈ Π² 2 Π³ΡΡΠΏΠΈ: Ρ Π½Π°ΡΠ°Π»Π½Π° Π³Π»Π°ΡΠΊΠΎΠΌΠ° ΠΠ ΠΎΡΠΈ ΠΈ Ρ Π½Π°ΠΏΡΠ΅Π΄Π½Π°Π»Π° Π³Π»Π°ΡΠΊΠΎΠΌΠ° 27 ΠΎΡΠΈ. ΠΠ° Π²ΡΠΈΡΠΊΠΈ ΠΎΠ±Ρ
Π²Π°Π½Π°ΡΠΈ Π² ΠΈΠ·ΡΠ»Π΅Π΄Π²Π°Π½Π΅ΡΠΎ ΠΎΡΠΈ ΡΠ° Π°Π½Π°Π»ΠΈΠ·ΠΈΡΠ°Π½ΠΈ GCC ΠΈ RNFL (ΠΏΠΎ 2 ΠΏΡΠΎΡΠΎΠΊΠΎΠ»Π° Π½Π° RTVue - ONH ΠΈ RNFL Π.45).Π Π΅Π·ΡΠ»ΡΠ°ΡΠΈ: Π‘ΡΠ΅Π΄Π½Π°ΡΠ° ΡΡΠΎΠΉΠ½ΠΎΡΡ Π½Π° GCC (GCC average) Π΅ Π½Π°ΠΉ-Π³ΠΎΠ»ΡΠΌΠ° ΠΏΡΠΈ Π½ΠΎΡΠΌΠ°Π»Π½ΠΈ ΠΎΡΠΈ, ΡΠ»Π΅Π΄Π²Π°Π½Π° ΠΎΡ ΡΠ°Π·ΠΈ ΠΏΡΠΈ Π³Π»Π°ΡΠΊΠΎΠΌΠ½ΠΈ ΠΎΡΠΈ Π² ΡΠ°Π½Π΅Π½ ΡΡΠ°Π΄ΠΈΠΉ ΠΈ Π³Π»Π°ΡΠΊΠΎΠΌΠ½ΠΈ ΠΎΡΠΈ Π² Π½Π°ΠΏΡΠ΅Π΄Π½Π°Π» ΡΡΠ°Π΄ΠΈΠΉ (96.7Β±5.3 Ρ/Ρ 81.0Β±9.45.3 Ρ/Ρ 75.0Β±16.8). ΠΠ΅ΠΆΠ΄Ρ ΠΎΡΠΈ Ρ ΡΠ°Π½Π½Π° ΠΈ Ρ Π½Π°ΠΏΡΠ΅Π΄Π½Π°Π»Π° Π³Π»Π°ΡΠΊΠΎΠΌΠ° Π½Π΅ ΡΠ΅ ΡΡΡΠ°Π½ΠΎΠ²ΡΠ²Π° ΡΡΠ°ΡΠΈΡΡΠΈΡΠ΅ΡΠΊΠΈ Π·Π½Π°ΡΠΈΠΌΠ° ΡΠ°Π·Π»ΠΈΠΊΠ° ΠΏΠΎ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠ΅ Π½Π° ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π»ΠΈΡΠ΅ GCC average, GCC superior ΠΈ GCC inferior. ΠΠ΅Π±Π΅Π»ΠΈΠ½Π°ΡΠ° Π½Π° ΠΏΠ΅ΡΠΈΠΏΠ°ΠΏΠΈΠ»Π°ΡΠ½ΠΈΡ Π½Π΅Π²ΡΠΎΡΠΈΠ±ΡΠΈΠ»Π΅ΡΠ΅Π½ ΡΠ»ΠΎΠΉ ΠΎΠ±Π°ΡΠ΅, ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½Π° ΠΈ ΠΏΠΎ Π΄Π²Π°ΡΠ° ΠΌΠΎΠ΄ΡΠ»Π°, ΡΠ΅ ΡΠ°Π·Π»ΠΈΡΠ°Π²Π° ΡΡΠ°ΡΠΈΡΡΠΈΡΠ΅ΡΠΊΠΈ Π·Π½Π°ΡΠΈΠΌΠΎ ΠΏΡΠΈ ΡΠ°Π½Π½Π° ΠΈ Π½Π°ΠΏΡΠ΅Π΄Π½Π°Π»Π° Π³Π»Π°ΡΠΊΠΎΠΌΠ° (Π <0.001).ΠΠ°ΠΊΠ»ΡΡΠ΅Π½ΠΈΠ΅: ΠΠ°ΡΠΈΡΠ΅ ΡΠ΅Π·ΡΠ»ΡΠ°ΡΠΈ ΠΏΠΎΠΊΠ°Π·Π²Π°Ρ, ΡΠ΅ ΠΈΠ·ΠΌΠ΅ΡΠ²Π°Π½Π΅ΡΠΎ Π½Π° ΠΏΠ΅ΡΠΈΠΏΠ°ΠΏΠΈΠ»Π°ΡΠ½ΠΈΡ RNFL Π΅ ΠΏΠΎ-Π½Π°Π΄Π΅ΠΆΠ΄Π΅Π½ ΠΠ‘Π’-ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π» Π·Π° ΠΏΡΠΎΡΠ»Π΅Π΄ΡΠ²Π°Π½Π΅ ΠΏΡΠΎΠ³ΡΠ΅ΡΠΈΡΡΠ° Π½Π° Π³Π»Π°ΡΠΊΠΎΠΌΠ°ΡΠ°.Purpose: To evaluate the quantitative measurements of ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (RNFL) obtained by optical coherent tomography (OCT) in different stages of open-angle glaucoma.Methods: Sixty eyes of 34 patients with open-angle glaucoma and 60 eyes of 30 healthy people are examined using RTV-ue 100 (Optovue Inc., Fremont, CA). According to visual field global indices MD and PSD (Humphrey Analyzer) glaucomatous eyes are separated into two groups: 33 eyes with early glaucoma and 27 eyes with advanced glaucoma. GCC and RNFL (using two scanning protocols of RTV-ue - ONH and RNFL 3.45) are analyzed in all of the eyes included in the study.Results: GCC average is with highest values in normal eyes, followed by the glaucomatous eyes in early stage and glaucomatous eyes in advanced stage (96.7Β±5.3Γ΄β¬ββ versus 81.0Β±9.4Γ΄β¬ββ versus 75.0Β±16.8Γ΄β¬ββ). Concerning the indices GCC average, GCC superior and GCC inferior in eyes with early and advanced glaucoma statistically significant difference is not found (respectively P=0.081, P=1.00, P=0.335). However, the thickness of the peripapillary nerve fiber layer, measured by the two scanning protocols, is statistically significantly different in early and advanced glaucoma (p<0.001).Conclusion: Our results show that measurement of the peripapillary RNFL is more reliable OCT indicator for follow-up of glaucoma progression
First-Principles Study of Optical Absorption Energies, Ligand Field and Spin-Hamiltonian Parameters of Cr<sup>3+</sup> Ions in Emeralds
Herein, we study the electronic structure, energies, and vibronic structure of optical d-d transitions of Cr3+ ions doped in beryl (Be3Si6Al2O18:Cr3+, emerald). A computational protocol is developed that combines periodic density functional theory (for modeling of the bulk crystalline lattice of emerald) and the multireference configuration interaction complete active space self-consistent field method supplemented with n-electron valence second-order perturbation theory (for the calculation of the energy levels, wave functions, and spin-Hamiltonian and ligand-field parameters of the trigonal Cr3+ centers in the [CrO6]9β clusters embedded in an extended point charge field). Ligand-field parameters were extracted from mapping the effective ligand-field Hamiltonian onto the full many-particle Hamiltonian from one side and from a direct fit to energies of computed d-d transitions on the other side. These have been analyzed using ab initio ligand-field theory. The quality of the theoretical predictions is critically assessed through a detailed comparison with the available experimental data
- β¦