Appearance-based localization for mobile robots using digital zoom and visual compass

This paper describes a localization system for mobile robots moving in dynamic indoor environments, which uses probabilistic integration of visual appearance and odometry information. The approach is based on a novel image matching algorithm for appearance-based place recognition that integrates digital zooming, to extend the area of application, and a visual compass. Ambiguous information used for recognizing places is resolved with multiple hypothesis tracking and a selection procedure inspired by Markov localization. This enables the system to deal with perceptual aliasing or absence of reliable sensor data. It has been implemented on a robot operating in an office scenario and the robustness of the approach demonstrated experimentally

New species of Clavicornaltica Scherer (Coleoptera: Chrysomelidae) from continental Asia

Four new species of Clavicornaltica Scherer are described and illustrated, of which two are from China (C. dali new species and C. longsheng new species) and two are from Vietnam (C. tamdao new species and C. vietnamensis new species). The wing and metathorax are described and illustrated for the genus for the first time. A key to the newly described species is presented. Male genitalia of Clavicornaltica australis Konstantinov are illustrated for the first time

Universities Confront ‘Tech Disruption’: Perceptions of Student Engagement Online Using Two Learning Management Systems

This article is a teaching note on the experiences of students and professors as they adapted to the use of a new learning management system (LMS). Using pedagogical theories of student engagement and the online learning process, we explore how the design of an LMS affects student satisfaction and interaction with peers and the instructor. This descriptive, qualitative study reports student and instructor experiences in four hybrid sociology courses that used Google Classroom as an experimental LMS. These same students also used Blackboard, a more traditional LMS, in their other sociology classes, establishing a quasi within-subject point of comparison for these two systems. A survey (n=72) and four focus groups (n=54) were conducted among students to determine how student engagement is experienced differently on Classroom and Blackboard. Eighty-three percent of students reported feeling satisfied with Classroom over Blackboard. Focus groups revealed themes relating to usability and learnability; interaction and individuality; and facilitation of learning. Students and instructors responded more positively, with some exceptions, to Classroom’s reliability and interface, but claims about the transformative power of online tools are not wholly supported by student or instructor experiences. The study advances our understanding of how the LMS interface, design, and functionality play a role in student engagement online. Further research is needed to understand the full extent of Classroom’s impact on learning in the higher education landscape

Discovery and Designation of Type Specimens of Chrysomelidae (Coleoptera) From Argentina Described by E. von Harold in 1875

Type specimens of 14 species of Chrysomelidae from Cordova, Argentina. collected by W. M. Davis and described by E. von Harold in 1875, were discovered in the collections of the Museum of Comparative Zoology (Harvard University). A few specimens from some other museums such as the Museum für Naturkunde der Humboldt-Universität (Berlin), The Natural History Museum (London), Institut Royal des Sciences Naturelles de Belgique (Brussels), Museo Nacional de Hungaria (Budapest) are also apparently from the original series. Lectotypes and paralectotypes are designated for all species

Notes on identity, new synonymy and larva of Ivalia Jacoby (Coleoptera: Chrysomelidae) with description of a new species

Genus Ivalia Jacoby is characterized morphologically, and Amphimeloides Jacoby syn. nov. and Taizonia Chen syn. nov. are junior synonyms with it. Several Ivalia species are figured, including Ivalia bella (Chen) comb. nov., I. dorsalis (Jacoby) comb. nov., and I. viridipennis Jacoby. A new species of Ivalia from the Nilgiri Hills in south India, I. korakundah sp. nov., is described and illustrated, including the larvae. Larvae were associated with adults by sequencing a fragment of the mitochondrial gene cytochrome oxidase I. Larval morphology is discussed and compared with that of other flea beetles

Notes on identity, new synonymy and larva of Ivalia Jacoby (Coleoptera: Chrysomelidae) with description of a new species

Genus Ivalia Jacoby is characterized morphologically, and Amphimeloides Jacoby syn. nov. and Taizonia Chen syn. nov. are junior synonyms with it. Several Ivalia species are figured, including Ivalia bella (Chen) comb. nov., I. dorsalis (Jacoby) comb. nov., and I. viridipennis Jacoby. A new species of Ivalia from the Nilgiri Hills in south India, I. korakundah sp. nov., is described and illustrated, including the larvae. Larvae were associated with adults by sequencing a fragment of the mitochondrial gene cytochrome oxidase I. Larval morphology is discussed and compared with that of other flea beetles

Vision-based landing of a simulated unmanned aerial vehicle with fast reinforcement learning

Landing is one of the difficult challenges for an unmanned aerial vehicle (UAV). In this paper, we propose a vision-based landing approach for an autonomous UAV using reinforcement learning (RL). The autonomous UAV learns the landing skill from scratch by interacting with the environment. The reinforcement learning algorithm explored and extended in this study is Least-Squares Policy Iteration (LSPI) to gain a fast learning process and a smooth landing trajectory. The proposed approach has been tested with a simulated quadrocopter in an extended version of the USARSim Unified System for Automation and Robot Simulation) environment. Results showed that LSPI learned the landing skill very quickly, requiring less than 142 trials

DISCOVERY AND DESIGNATION OF TYPE SPECIMENS OF CHRYSOMELIDAE (COLEOPTERA) FROM ARGENTINA DESCRIBED BY E. VON HAROLD IN 1875

ABSTRAC

Photochemical pump and NMR probe : Chemically created NMR coherence on a microsecond time scale

We report pump-probe experiments employing laser-synchronized reactions of para-hydrogen (para-H2) with transition metal dihydride complexes in conjunction with nuclear magnetic resonance (NMR) detection. The pump-probe experiment consists of a single nanosecond laser pump pulse followed, after a precisely defined delay, by a single radio frequency (rf) probe pulse. Laser irradiation eliminates H2 from either Ru(PPh3) 3(CO)(H)2 1 or cis-Ru(dppe)2(H)2 2 in C6D6 solution. Reaction with para-H2 then regenerates 1 and 2 in a well-defined nuclear spin state. The rf probe pulse produces a high-resolution, single-scan 1H NMR spectrum that can be recorded after a pump-probe delay of just 10 μs. The evolution of the spectra can be followed as the pump-probe delay is increased by micro- or millisecond increments. Due to the sensitivity of this para-H2 experiment, the resulting NMR spectra can have hydride signal-to-noise ratios exceeding 750:1. The spectra of 1 oscillate in amplitude with frequency 1101 ± 3 Hz, the chemical shift difference between the chemically inequivalent hydrides. The corresponding hydride signals of 2 oscillate with frequency 83 ± 5 Hz, which matches the difference between couplings of the hydrides to the equatorial 31P nuclei. We use the product operator formalism to show that this oscillatory behavior arises from a magnetic coherence in the plane orthogonal to the magnetic field that is generated by use of the laser pulse without rf initialization. In addition, we demonstrate how chemical shift imaging can differentiate the region of laser irradiation thereby distinguishing between thermal and photochemical reactivity within the NMR tube