Rotation Of Object Research Articles

An Advanced Pharmacy Practice Experience in Leadership Development

Objective. To describe the development and implementation of an advanced pharmacy practice experience (APPE) in leadership.Methods. A leadership APPE was created and continuously improved over five years from being mostly content-oriented to being more of an experiential offering by identifying and implementing rich, practical leadership experiences. Activities included PhotoVoice, Power of Full Engagement, What's Your Passion?, Transformational Leadership, Speech Acts, a Mindfulness Retreat, PeoplePack Dynamics, and a rowing experience at an Olympic training facility. After five years of developing and refining the APPE, faculty coordinators sought student feedback on the APPE beyond using a standardized APPE evaluation form students complete at the end of each rotation.Results. The majority of students agreed with all of the evaluation items. Items with the highest mean agreement included: content from previous didactic leadership courses were reinforced in the rotation; relevance of the rotation to one's career; rotation objectives facilitated learning; and a variety of teaching methods helped in applying knowledge to future practice. Analysis of comments regarding the leadership APPE identified three main themes: gratitude, development, and more connection.Conclusion. An elective APPE with the primary purpose of leadership training and development can be created and incorporated into the Doctor of Pharmacy curriculum. This leadership APPE can serve as an example for other institutions interested in implementing a similar experience.

Arbitrary-Oriented Object Detection on High Resolution Images Based on Differentiable Architecture Search

High-resolution images exhibit wide field of vision, high background complexity, special angle of view, rotation, and small objects, thus making automatic object detection a challenging problem. Recently, this problem has been studied by many researchers through the application of deep learning methods, and good detection results have been achieved. However, most of the current networks for object detection on remote sensing images are designed manually, which is not necessarily the optimal structure. Therefore, DARTS-FPN, a network based on differentiable architecture search, has been constructed to improve the accuracy of object detection on high resolution images. The DARTS algorithm is first used to search the remote sensing images data set. The neural architecture search technique of NAS-FPN is then integrated into this network and merged with RetinaNet, a single-stage rotating network for object detection. Experiments are conducted on the DOTA data set to evaluate the performance of DARTS-FPN. Compared with existing classical networks, DARTS-FPN achieves 55.86%, 45.06%, 5.78%, and 2.19% higher mean average precision than the SSD, YOLOv2, R2CNN, and DM algorithms, respectively.

Detecting Yaw and Pitch Change With Single Millimeter-Wave CW Radar

The accurate detection of angle change of a rotated object is proposed using radar technology. A 24-GHz continuous-wave radar associated with three modulation transponders is designed and implemented. When the relative displacement of the transponders attached on the rotated object are detected by the ranging radar, the corresponding yaw and pitch angle changes can be obtained from the angle-displacement transformation. The measurement shows that this system is capable of distinguishing multiple transponders, and the mm-scale displacement can be successfully detected. Both yaw and pitch angle change is estimated from displacements with the resultant rms angle error as 0.74° and 1.00° within ±45° rotation range.

Thermophysical Investigation of Asteroid Surfaces. I. Characterization of Thermal Inertia

Abstract The thermal inertia of an asteroid is an indicator of the thermophysical properties of the regolith and is determined by the size of grains on the surface. Previous thermophysical modeling studies of asteroids have identified or suggested that object size, rotation period, and heliocentric distance (a proxy for temperature) are important factors that separately influence thermal inertia. In this work we present new thermal inertia values for 239 asteroids and model all three factors in a multivariate model of thermal inertia. Using multiepoch infrared data of this large set of objects observed by WISE, we derive the size, albedo, thermal inertia, surface roughness, and sense of spin using a thermophysical modeling approach that does not require a priori knowledge of an object’s shape or spin axis direction. Our thermal inertia results are consistent with previous values from the literature for similarly sized asteroids, and we identify an excess of retrograde rotators among main-belt asteroids <8 km. We then combine our results with thermal inertias of 220 objects from the literature to construct a multivariate model and quantify the dependency on asteroid diameter, rotation period, and surface temperature. This multivariate model, which accounts for codependencies between the three independent variables, identifies asteroid diameter and surface temperature as strong controls on thermal inertia.

Remote sensing target detection in a harbor area based on an arbitrary-oriented convolutional neural network

With the rapid development of optical remote sensing, it is urgent to find a reliable target detection method. Compared with traditional detection algorithms, a convolutional neural network has attracted considerable attention owing to its efficiency and high transitivity. However, different from general images, remote sensing images contain complex background information and dense small targets with changeable directions that make detection very challenging. To solve these problems and provide a stable and high-performance detection method, a rotated saliency fusion object detection (RSD) model based on “you only look once” (YOLO)v4 is established. First, salient image fusion technology is used to magnify target information. Second, the angle variable and rotated non-maximal suppression is introduced to improve the accuracy of rotated object detection by including the detection of dense objects. Third, the network structure is enhanced to improve the performance of small-target detection. Finally, the k-means algorithm and data enhancement are introduced to increase the robustness of the model. Extensive experiments demonstrate the superiority of the proposed model in detection speed and accuracy. The mean average precision of the proposed RSD model reaches 97.32% for the remote sensing images in a harbor area with an average detection speed of 13.41 s − 1.

ADT-Det: Adaptive Dynamic Refined Single-Stage Transformer Detector for Arbitrary-Oriented Object Detection in Satellite Optical Imagery

The detection of arbitrary-oriented and multi-scale objects in satellite optical imagery is an important task in remote sensing and computer vision. Despite significant research efforts, such detection remains largely unsolved due to the diversity of patterns in orientation, scale, aspect ratio, and visual appearance; the dense distribution of objects; and extreme imbalances in categories. In this paper, we propose an adaptive dynamic refined single-stage transformer detector to address the aforementioned challenges, aiming to achieve high recall and speed. Our detector realizes rotated object detection with RetinaNet as the baseline. Firstly, we propose a feature pyramid transformer (FPT) to enhance feature extraction of the rotated object detection framework through a feature interaction mechanism. This is beneficial for the detection of objects with diverse patterns in terms of scale, aspect ratio, visual appearance, and dense distributions. Secondly, we design two special post-processing steps for rotated objects with arbitrary orientations, large aspect ratios and dense distributions. The output features of FPT are fed into post-processing steps. In the first step, it performs the preliminary regression of locations and angle anchors for the refinement step. In the refinement step, it performs adaptive feature refinement first and then gives the final object detection result precisely. The main architecture of the refinement step is dynamic feature refinement (DFR), which is proposed to adaptively adjust the feature map and reconstruct a new feature map for arbitrary-oriented object detection to alleviate the mismatches between rotated bounding boxes and axis-aligned receptive fields. Thirdly, the focus loss is adopted to deal with the category imbalance problem. Experiments on two challenging satellite optical imagery public datasets, DOTA and HRSC2016, demonstrate that the proposed ADT-Det detector achieves a state-of-the-art detection accuracy (79.95% mAP for DOTA and 93.47% mAP for HRSC2016) while running very fast (14.6 fps with a 600 × 600 input image size).

Analysis of the space debris objects nozzle capture dynamic processed by a telescopic robotic arm

The paper considers a new layout of a two-stage spacecraft designed to remove a group of large space debris objects such as the upper stages of ‘Zenit’ launch vehicles from low-earth orbit. The aim of the work is to preliminarily quantify the parameters of the shock-absorbing system of the robotic arm designed for capturing a redundant upper stage by the main rocket engine nozzle. The estimation will be conducted by means of numerical simulation of the motion dynamics of the "spacecraft - space debris object" system. The paper presents the results of calculating the transient mode of oscillations of objects connected by the manipulator using simplified and detailed dynamic models of parameters, the analysis of the placement options for the manipulator shock-absorbing system, the analysis of the load reduction possibility through the use of attitude control thrusters, the analysis of two dynamic design variants of the mechanism for grabbing the critical section of the nozzle, and analysis of the capture dynamics at different initial angular velocities of rotation of a space debris object. The most rational shock-absorbing solution for a robotic arm with two translational and two rotary dampers is found. It is shown that the dynamic design of the nozzle capture mechanism has the greatest effect on the robotic arm loading. The kinematic design of the gripper selected as a result of the simulation almost completely eliminates shock loads in the process of damping the system vibrations. It is shown that the robotic arm shock-absorbing design has a significant margin for the initial angular velocity of the space debris object.

Superradiant scattering of orbital angular momentum beams

We consider the wave-structure coupling between an orbital angular momentum beam and a rapidly rotating disk, and present a new configuration exhibiting the wave amplification effect known as rotational superradiance. While initially envisioned in terms of the scattering of an incident wave directed perpendicular to an object's rotation axis, we demonstrate in the context of acousto-mechanics that superradiant amplification can also occur with a vortex beam directed parallel to the rotation axis. We propose two different experimental routes: one must either work with rotations high enough that the tangential velocity at the outer edge of the disk exceeds the speed of sound, or use evanescent sound waves. We argue that the latter possibility is more promising, and provides the opportunity to probe a previously unexamined parameter regime in the acoustics of rotating porous media.

PolarDet: a fast, more precise detector for rotated target in aerial images

ABSTRACT Fast and precise object detection for hgigh-resolution aerial images has been a challenging task over the years. Due to the sharp variations in object scale, rotation, and aspect ratio, most existing methods are inefficient and imprecise. In this paper, we propose a different approach polar method. We locate an object by centre-point, direct it by four polar angles, and measure it by polar ratio system. Our polar coordinate-based method, PolarDet, is a faster, simpler, and more accurate one-stage object detector. Also, our detector introduces a sub-pixel centre semantic structure to further improve classifying veracity. PolarDet achieves nearly all state-of-the-art (SOTA) performance in aerial object detection tasks with faster inference speed. In detail, our approach obtains the SOTA results on authoritative remote sensing object detection datasets DOTA, UCAS-AOD, and HRSC2016 with 76.64% mAP (mean average precision), 97.01% mAP, and 90.46% mAP respectively. Most noticeably, our PolarDet gets the best performance and reaches the fastest speed (32fps) at the UCAS-AOD dataset.

Role of manually-generated visual cues in crawling and non-crawling 9-month-old infants’ mental rotation

This study investigated the role of manually self-generated visual cues on crawling and non-crawling 9-month-old infants’ mental rotation. Forty-three infants were tested using a simplified Shepard-Metzler task to measure mental rotation performance. Prior to the mental rotation task, infants were given the opportunity to manually rotate either a vertically- or a horizontally-striped cylinder around the same vertical movement axis as the mental rotation objects (see Antrilli & Wang, 2016). Results revealed that while there were no signs of mental rotation in non-crawlers, crawlers in the vertical-stripe condition showed a novelty preference, whereas crawlers in the horizontal-stripe condition preferred to look at the familiar test object during the mental rotation task. This suggests that crawling is associated with a more differentiated processing of self-generated rotation-specific visual cues than non-crawling.

Evaluating the Reaction to a Complex Rotated Object in the American Quarter Horse (Equus caballus).

Simple SummaryHorses are prey animals and exhibit behaviors that help them adapt and survive in their environment. These reactions are often referred to as spooking and they have the potential to be dangerous to the horse, handler and rider. Spooking consists of avoidance reactions that include suddenly moving away or running away from the perceived danger. It is dangerous for both riders and horses when a horse suddenly startles. Sometimes horses do this in familiar environments because familiar objects may look different when rotated. The purpose of this study was to determine whether horses that had been habituated to a complex object (children’s playset) would react to the object as novel when rotated 90 degrees. Twenty young horses were led past the playset 15 times by a handler. Next, the rotated group was led past the rotated playset 15 times. Each time the horse was led by the object was counted as a pass. An increasing reactivity scale was used to quantify behavioral responses. Being aware of potential reactions to changes in the orientation of previously familiar objects can help keep the handler safer. It is dangerous for both riders and horses when a horse suddenly startles. Sometimes horses do this in familiar environments because familiar objects may look different when rotated. The purpose of this study was to determine whether horses that had been habituated to a complex object (children’s playset) would react to the object as novel when rotated 90 degrees. Twenty young horses were led past the playset 15 times by a handler. Next, the rotated group was led past the rotated playset 15 times. Each time the horse was led by the object was a pass. The behavioral responses observed and analyzed were ears focused on the object, nostril flares, neck raising, snort, avoid by stopping, avoid by moving feet sideways, and avoid by flight. An increasing reactivity scale was used to quantify behavioral responses. A two-sample t-test was performed on the reactivity scores comparing the first pass by the novel object to the first pass by the rotated object. The horses in the rotated group reacted to the rotated orientation similarly to the first exposure (p = 0.001, α < 0.05). Being aware of potential reactions to changes in previously familiar environments can help keep the handler safer.

Oriented Bounding Boxes for Small and Freely Rotated Objects

A novel object detection method is presented that handles freely rotated objects of arbitrary sizes, including tiny objects as small as $2\times 2$ pixels. Such tiny objects appear frequently in remotely sensed images, and present a challenge to recent object detection algorithms. More importantly, current object detection methods have been designed originally to accommodate axis-aligned bounding box detection, and therefore fail to accurately localize oriented boxes that best describe freely rotated objects. In contrast, the proposed CNN-based approach uses potential pixel information at multiple scale levels without the need for any external resources, such as anchor boxes.The method encodes the precise location and orientation of features of the target objects at grid cell locations. Unlike existing methods which regress the bounding box location and dimension,the proposed method learns all the required information by classification, which has the added benefit of enabling oriented bounding box detection without any extra computation. It thus infers the bounding boxes only at inference time by finding the minimum surrounding box for every set of the same predicted class labels. Moreover, a rotation-invariant feature representation is applied to each scale, which imposes a regularization constraint to enforce covering the 360 degree range of in-plane rotation of the training samples to share similar features. Evaluations on the xView and DOTA datasets show that the proposed method uniformly improves performance over existing state-of-the-art methods.

Analysing Students’ Spatial Abilities in Chemistry Learning Using 3D Virtual Representation

Students often have difficulty understanding abstract concepts in chemistry and a low spatial ability, especially in visualizing intermolecular interactions at the submicroscopic level. Therefore, this study aims to analyze the spatial ability of students by using a 3D virtual representation as they study the curriculum topic of molecular geometry. The research was conducted with 13 male and 23 female year 10 secondary students in Jakarta, Indonesia. A qualitative methodology was employed to analyze students’ spatial abilities while they undertook learning activities using 3D virtual representation. Data collection included a spatial assessment, a quiz about prior knowledge, student worksheets, interviews, observation sheets, reflective journals, and a molecular geometry test. Learning was carried out in three stages; engage, explore, and explain. The results of the research show that students’ ability in spatial orientation is low whereas their ability in spatial relationships that involve using mental manipulation and rotation of 2D or 3D objects is more developed. Students employ this approach to develop their understanding of molecular geometry.

Multiphase Direct AC Wireless Power Transfer System: Comparative Proposals Using Frequency and Amplitude Modulations

Using multiload wireless power transfer (WPT) systems to supply power to multiple receivers with a single transmitter is an interesting topic. However, previous studies are all based on a dc–dc WPT system. If the loads demand ac power, additional dc–ac inverters need to be implemented, which increases the system complexity and cost. This article addresses two direct ac WPT systems that can regulate the ac power of multiple phases or loads independently, using frequency modulation and amplitude modulation (AM), respectively. The proposed WPT systems can directly control the ac power of multiple loads through the transmitter side, without any power converter at the receiver side. A typical application of the proposed system is for powering a three-phase load in a rotational object, e.g., three-phase motors in articulated robots or in-wheel motors. To demonstrate the feasibility of the proposed WPT systems, simulation and experiment studies of a wireless three-phase power transfer are presented. The results suggest that AM is a more advantageous solution to a direct ac WPT system. A power-loss breakdown analysis is presented to suggest future steps of efficiency improvement.

Shape-driven optofluidic rotational actuation

In the present work, we report light-induced rotation of millimeter-sized objects driven by their non-symmetric shape. The light-induced torque is originated by the thermal gradient on different sides of the teeth of star-shaped objects floating on liquid surfaces that leads to unbalanced surface tension due to the Marangoni effect. The dependence of the angular rotation on the number of teeth is demonstrated. The angular velocity is linearly dependent on the light intensity and follows a simple time behavior typical of objects moving under fluid friction.Graphic abstract

Measuring the Gravitomagnetic Distortion from Rotating Halos. I. Methods

Abstract Source galaxy images are distorted not only by a static gravitational potential, but also by frame-dragging induced by massive rotating objects like clusters of galaxies. Such an effect is well understood theoretically; it is therefore of great interest to estimate its detectability for future surveys. In this work, we analyze the lensing convergence κ around rotating dark matter halos. The rotation of the massive objects generates a gravitomagnetic potential giving rise to an anisotropic contribution to the lensing potential. We construct an estimator δ κ to describe the difference between the symmetric enhancement and reduction of κ around the halo rotation axis, finding that it is well approximated by a function proportional to the halo velocity dispersion squared times a dimensionless angular momentum parameter. Using simulation mocks with realistic noise level for a survey like the Legacy Survey of Space and Time (LSST), we test our estimator, and show that the signal from frame-dragging of stacked rotating lenses is consistent with zero within 1σ. However, we find that the most massive cluster in SDSS DR7 spectroscopic selected group catalog has a line-of-sight rotation velocity of 195.0 km s−1 and velocity dispersion of 667.8 km s−1, which is at 1.2 × 10−8 odds according to the angular momentum probability distribution inferred from N-body simulations. By studying SDSS DR7 spectroscopic selected group catalog, we show how rotating clusters can be identified, and, finding that fast rotating clusters might be more abundant than in estimates based on simulations, a detection of gravitomagnetic distortion may be at reach in future surveys.

CENTRAL AND LOGARITHMIC CENTRAL IMAGE CHORD TRANSFORMATIONS FOR INVARIANT OBJECT RECOGNITION

Pattern descriptors invariant to rotation, scaling, and translation represents an important direction in the elaboration of the real time object recognition systems. In this article, the new kinds of object descriptors based on chord transformation are presented. There are described new methods of image presentation - Central and Logarithmic Central Image Chord Transformations (CICT and LCICT). It is shown that the CICToperation makes it possible to achieve invariance to object rotation. In the case of implementation of the LCICT transformation, invariance to changes in the rotation and scale of the object is achieved. The possibilities of implementing the CICTand LCICToperations are discussed. The algorithms of these operations for contour images are presented. The possibilities of integrated implementation of CICT and LCICT operations are considered. A generalized CICT operation for a full (halftone) image is defined. The structures of the coherent optical processors that implement operations of basic and integral image chord transformations are presented.

ВЛИЯНИЕ МАГНИТНОГО ЗАРЯДА НА ЭФФЕКТ САНЬЯКА В ПРОСТРАНСТВЕ-ВРЕМЕНИ БАРДИНА

This paper investigates one of the most interesting effects associated with the rotation of astrophysical objects (the Sagnac effect). The effect was first confirmed in laboratory experiments by Georges Sagnac with a rotating ring interferometer in 1913. Later, the effect was also confirmed within the framework of the Earth in the "Around-the-World" experiment conducted by J. Hafele and R. Kitting, in which they twice circled the Earth with an atomic cesium clock on board and compared the "flying" clock with those remaining static on the Earth. As a result, a non-zero difference in the clock rate was found as a confirmation of the Sagnac effect. Subsequently, more precise satellite experiments have been carried out to measure the Sagnac effect within the Earth. The effect was also considered in general relativity and modified theories of gravity, where many works were carried out to study the influence of such parameters as angular momentum, cosmological constant, Ricci scalar, etc. on the Sagnac effect. An interesting task is to study the influence of a magnetic charge on the effect, since the solution with rotation described by a black hole with mass M and magnetic charge g is the Bardeen nonsingular black hole. The work will calculate the Sagnac effect in the space-time of the rotating Bardeen black hole for both geodesic and non-geodesic circular orbits of the light source / receiver (assuming that the light source and receiver are defined at the same point). Two types of circular orbits describe the opposing influence on the Sagnac effect: the Sagnac delay increases with an increase in the magnetic charge in the case of non-geodesic circular orbits and decreases in the case of geodesic circular orbits. However, the farther is the orbit of the light source / receiver, the less the magnetic charge affects the Sagnac delay. It is also assumed that the gravity of the Earth and the Sun near the surface is well described by the Bardeen metric.

Electromagnetic tests of horizonless rotating black hole mimickers

The interest in the implications that astrophysical observations have for the understanding of the structure of black holes has grown since the first detection of gravitational waves. Many arguments that are put forward in order to constraint alternative black hole models rely on substantial assumptions such as perfect spherical symmetry, which implies absence of rotation. However, given that astrophysical black holes will generally exhibit nonzero angular momentum, realistic constraints must take into account the effects of rotation. In this work we analyze the gravitational effect that rotation has on the emission from the surface of ultracompact objects, by studying how angular momentum affects the propagation of light rays. This allows us to evaluate the reliability of the constraints derived for supermassive black holes (more specifically, Sagittarius A* and M87*) assuming lack of rotation, as presented in [Astrophys. J. 701, 1357 (2009); Astrophys. J. 805, 179 (2015)]. We find that for rapidly spinning objects rotation can significantly affect the escaping probability of photon emitted from the surface of the object, with a significant increase at the equatorial regions and a decrease at the poles with respect to the non-rotating case. For not so rapidly spinning black hole candidates like Sagittarius A*, such modifications do not affect significantly the present constraints, which are nevertheless weaker than originally supposed due to the relativistic lensing here considered and additional phenomenological parameters that describe basic processes such as absorption. However, taking into account the angular dependence of the superficial emission of rapidly spinning black hole mimickers will be necessary for future studies of objects like e.g. M87*.

Learning to Place Objects Onto Flat Surfaces in Upright Orientations

We study the problem of placing a grasped object on an empty flat surface in an upright orientation, such as placing a cup on its bottom rather than on its side. We aim to find the required object rotation such that when the gripper is opened after the object makes contact with the surface, the object would be stably placed in the upright orientation. We iteratively use two neural networks. At every iteration, we use a convolutional neural network to estimate the required object rotation, which is executed by the robot, and then a separate convolutional neural network to estimate the quality of a placement in its current orientation. Our approach places previously unseen objects in upright orientations with a success rate of 98.1% in free space and 90.3% with a simulated robotic arm, using a dataset of 50 everyday objects in simulation experiments. Real-world experiments were performed, which achieved an 88.0% success rate, which serves as a proof-of-concept for direct sim-to-real transfer.