Continual Motion Research Articles

Studies of multisensory integration in sound localization and updating of auditory spatial attention during head motion

In daily life, our heads are in continual motion, but much of our knowledge of spatial hearing is based on experimental paradigms in which this behavior is discouraged or prevented. Head motion can benefit spatial hearing though the creation of dynamic acoustical cues, but also creates challenges such as the need to update head-centered spatial representations or the locus of spatial auditory attention. To utilize acoustic information generated by, or to compensate for, head movements, the auditory system must integrate self-motion information provided by other sensory systems. This presentation will review and contextualize a series of studies from the author's laboratory focused on the psychophysics of dynamic sound localization and the weighting of sensory information from vestibular, proprioceptive, and visual modalities in dynamic localization and maintenance of spatially selective auditory attention during head rotation. Notable findings include a velocity-independent ∼100-ms minimum stimulus duration for disambiguation of front/rear location in dynamic localization and the apparent dominance of vestibular information in the interpretation of dynamic localization cues and in attentional updating. The approach taken provides a step towards understanding the effects of naturalistic behavior on spatial hearing while maintaining significant experimental control and repeatability of stimuli and head movements.

Unsheltered Homelessness in Public Natural Areas Across an Urban-to-Wildland System: Institutional Perspectives

This article conceptualizes homelessness on public lands within a social-ecological systems framework, exploring dynamics in public natural areas in the Seattle metropolitan area (USA), a system with a compact urban-to-wildland gradient. While prior research has studied the dynamics of unsheltered homelessness within particular parks or cities—often in areas where camping is prohibited—our interview-based study makes integrated considerations of these dynamics across a range of jurisdictions. We present a thematic analysis that examines professionally diverse perspectives on the dynamics, stressors, and outcomes of public natural area usage by unsheltered individuals. We found a generally uncoordinated system in continual motion, in which considerable resources were expended for short-term, site-specific solutions that yielded system-wide detrimental outcomes perceived for unsheltered individuals, social service and environmental institutions, and ecosystem health. We discuss how improved institutional coordination and mutual understanding about intersecting governance systems could sustain better public land, public health, and social outcomes.

Review on Automatic Antenna Tracking System For LEO Satellites

Abstract: This paper is about comparing the Yagi- Uda Antenna, Turnstile Antenna, Parabolic Antenna Phased Array Antenna with a different parameters required to track LEO Satellites and to receive the Telemetry Information from them. LEO Satellites is Low Earth Orbit typically organized as a satellite constellation. The number of Satellite LEO would be ten to even thousand to fully cover the globe. As LEO satellites move very quickly and are most visible for 20to 30 min during each pass, it requires an antenna that can track signals, and satellite paths, and upload anddownload as much data as possible in a short amount of time. The continual motion of tracing one LEO satellite after other equates to significant mechanical performance. So in this paper, we carry out a review of which antenna suites are best for tracking the LEO, getting data from them, and also the mechanical parameter of Antennas.

An electric molecular motor

Macroscopic electric motors continue to have a large impact on almost every aspect of modern society. Consequently, the effort towards developing molecular motors1–3 that can be driven by electricity could not be more timely. Here we describe an electric molecular motor based on a [3]catenane4,5, in which two cyclobis(paraquat-p-phenylene)6 (CBPQT4+) rings are powered by electricity in solution to circumrotate unidirectionally around a 50-membered loop. The constitution of the loop ensures that both rings undergo highly (85%) unidirectional movement under the guidance of a flashing energy ratchet7,8, whereas the interactions between the two rings give rise to a two-dimensional potential energy surface (PES) similar to that shown by FOF1 ATP synthase9. The unidirectionality is powered by an oscillating10 voltage11,12 or external modulation of the redox potential13. Initially, we focused our attention on the homologous [2]catenane, only to find that the kinetic asymmetry was insufficient to support unidirectional movement of the sole ring. Accordingly, we incorporated a second CBPQT4+ ring to provide further symmetry breaking by interactions between the two mobile rings. This demonstration of electrically driven continual circumrotatory motion of two rings around a loop in a [3]catenane is free from the production of waste products and represents an important step towards surface-bound14 electric molecular motors.

Poetic Language in Plato’s Cratylus

This paper addresses Socrates’ claim in the Cratylus that he and Hermogenes must learn of the correctness of names from “Homer and the other poets.” I argue that, in treating poetry as the starting point for investigating the relationship of language to reality, Plato reveals language to be a discursive articulation of non-discursive divine Being. Thus, while language cannot fully capture Being once and for all, it can function as a moving image of it by being kept in continual motion. Poetic language, as divinely inspired, sits at the threshold between language’s discursivity and the unified reality it strives to articulate, and can therefore reinvigorate philosophical contemplation by de-sedimenting concepts articulated in language that have become stagnant, re-opening them for examination in new, previously unarticulated, ways. This vision of philosophical contemplation through language is part of a greater theme of the tension between mortal and divine modes of knowing. Humans desire divine understanding but only approach it through the motion of contemplation. Plato’s treatment of Apollo at 404e–406a reveals the two-fold nature of philosophical contemplation as relying on a certain tension between the revelation of the inarticulable, unchanging divine Being and the attempt to employ reason to test and interpret such disclosures through the unfolding motion of dialectic.

Deep-Learning Image Stabilization for Adaptive Optics Ophthalmoscopy

An adaptive optics scanning laser ophthalmoscope (AOSLO) has the characteristics of a high resolution and a small field of view (FOV), which are greatly affected by eye motion. Continual eye motion will cause distortions both within the frame (intra-frame) and between frames (inter-frame). Overcoming eye motion and achieving image stabilization is the first step and is of great importance in image analysis. Although cross-correlation-based methods enable image registration to be achieved, the manual identification and distinguishing of images with saccades is required; manual registration has a high accuracy, but it is time-consuming and complicated. Some imaging systems are able to compensate for eye motion during the imaging process, but special hardware devices need to be integrated into the system. In this paper, we proposed a deep-learning-based algorithm for automatic image stabilization. The algorithm used the VGG-16 network to extract convolution features and a correlation filter to detect the position of reference in the next frame, and finally, it compensated for displacement to achieve registration. According to the results, the mean difference in the vertical and horizontal displacement between the algorithm and manual registration was 0.07 pixels and 0.16 pixels, respectively, with a 95% confidence interval of (−3.26 px, 3.40 px) and (−4.99 px, 5.30 px). The Pearson correlation coefficients for the vertical and horizontal displacements between these two methods were 0.99 and 0.99, respectively. Compared with cross-correlation-based methods, the algorithm had a higher accuracy, automatically removed images with blinks, and corrected images with saccades. Compared with manual registration, the algorithm enabled manual registration accuracy to be achieved without manual intervention.

Structure Design and Solution of Kinematics of Robot Manipulator for 3D Concrete Printing

In relation to automated 3D concrete construction printing, a structure design of a suitable robot manipulator is presented as well as analytical solutions of related kinematics. The proposed structure has a higher number of degrees of freedom which can significantly increase the dexterity of a robot end-effector carrying a printing head. It should perform a continual motion along complicated large-scale printing trajectories. The related robot kinematics is derived by a novel representation of working layers in the complex plane using exponential functions. It leads to an explicit derivation of kinematic equations. The theoretical results are presented by examples of motion trajectories with typical configurations of the proposed structure. Note to Practitioners—This paper deals with a design of suitable robot structures for 3D concrete printing. Such concept is determined for on-site printing of residential houses. This area is developing a lot, but without a systematic design of energy-efficient, space-fitting robotic arms. A suitable structure is proposed, including a kinematic description to determine joint coordinates necessary for robot motion control. To ensure continuous energy-balanced motion during a large-scale printing, the redundant links in the structure are also used. Next research tasks focus on trajectory optimisation in complex print profiles.

An injectable peptide hydrogel with excellent self-healing ability to continuously release salvianolic acid B for myocardial infarction

Drug-loaded hydrogels can improve blood supply and inhibit extracellular matrix degradation after myocardial infarction. However, due to the continual dynamic motion of cardiac tissue, the hydrogel structure cannot be reconstructed in time, causing accelerated degradation and drug burst release. Here, a novel, superior, self-healing elastin-mimic peptide hydrogel (EMH) was fabricated for the local delivery of salvianolic acid B (SaB). The self-healing ability of EMH is enhanced by SaB-loaded polydopamine nanoparticles (SaB-PDA). In vitro, the pre-hydrogel (SaB-PDA/pre-EMH) is endowed with excellent biocompatibility and a low viscosity, making it suitable for intramyocardial injection. Once injected into the myocardial infarction (MI) region, SaB-PDA/pre-EMH can form SaB-PDA/EMH with great mechanical strength under the action of upregulated transglutaminase (TGase) in heart tissue post-MI. The superior self-healing ability of SaB-PDA/EMH allows for an increase in retention time in the beating ventricular wall. Therefore, with long-term release of SaB, SaB-PDA/EMH can inhibit ventricular remodeling and promote angiogenesis for MI treatment.

Translating Whispers: Recitation, Realism, Religion

The essay analyzes the beginning of the seventh chapter of Naguib Mahfouz›s Palace Walk in which, at the heart of this realist novel, we encounter a vivid description of Qur’anic recitation. The scene does not discuss what is recited so much as it offers an account of how. “His voice could not be heard,” we are told, “but the continual motion of his lips gave him away. From time to time a faint whisper slipped out in a sibilant s sound.” What is a minor detail in a novel otherwise filled with events reveals a sort of literary limit to the descriptive labor of realism. In the translator’s use of “sibilant s sound” is a creative rendering of the Arabic letters sīn and ṣād and the evocation of waswasa. Drawing together reflections on the whispered s and the speaking body, this essay considers the potentials of language folding upon itself, torn between the tongue of the speaker described in prose and the poetic resonance of the Qur’anic verse. Alongside discussions of the postlingual turn, this whispered detail invites reflections on registers of discourse both liturgical and literary.

Good vibrations: living with the motions of our unsettled planet

Abstract. By its very nature Earth is unsettled and in continual motion. Earthquakes and volcanoes are an expression of the convective motions of the planet, and our existence on Earth is a consequence of this tectonic activity. Yet, as humans, we often struggle to understand our role in relation to such unpredictable natural phenomena and use different methods to attempt to find order in nature's chaos. In dwelling on the surface of our “unsettled planet”, we adapt and live with a range of ground vibrations, both natural and anthropogenic in origin. Our project, funded by the University of Bristol's Brigstow Institute, seeks to explore how we perceive and understand the shaky ground we live on, using an interdisciplinary approach that brings together the Earth sciences, the history of art and literature, and performance art. Inspired by historical commentary in the aftermath of large earthquakes, which frequently notes the unscheduled ringing of church bells excited by the shaking around them, we reflect on how these purported unscheduled bell-ringing events were caused not only by near earthquakes but also by distant incidents. To investigate this phenomenon, we installed a state-of-the-art broadband seismometer in the Wills Memorial Building tower to record how Great George (the tower bell) responds to the restless world around him. The installed seismometer has been recording activity around and within the tower on a near-continuous basis between late-March 2018 and January 2019. Here, we present the signals recorded by the seismometer as Great George overlooks the hustle and bustle of the city around him and investigate how connected we are to our unsettled planet, even from our tectonically quiet setting in Bristol. We find that the seismometer not only shows the ebb and flow of activity in and around Bristol but also registers earthquakes from as nearby as Lincolnshire, UK, or as far away as Fiji, halfway around the world. In order to contextualize our findings, our project also considers what determines how people have responded to earth-shaking events, drawing on both historical and recent examples, and looks to contemporary art practice to consider how an awareness of our unsettled planet can be communicated in new ways. The project has led to a number of art installations and performances, and feedback from artists and audiences shows how making art can be used to both investigate our connections with the Earth and to articulate (and even accept) the uncertainties inherent in encountering unstable ground.

Designing Ordered Structure with Piezoceramic Actuation Units (OSPAU) for Generating Continual Nanostep Motion.

Continual precision actuations with nanoscale resolution over large ranges have extensive requirements in advanced intelligent manufacturing and precise surgical robots. To produce continual nanostep motion, conventionally, multiple pairs of piezo‐actuators are employed to operate in inchworm principle under complex three‐ or four‐phase timing signal drive. Inspired by the idea of ordered structures with functional units, a much simpler nanostep piezoelectric actuator consisting of (2 × 2) arrayed, cofired multilayer piezoceramic actuation units is developed, which operates in an artificially generated quasi shear mode (AGQSM) that is missing in natural piezoelectric ceramics. Under only one‐phase square‐wave voltage drive, the actuator can produce a stable, continual nanostep motion in two ways at nonresonant frequencies, and the obtained minimum step displacement is as low as 7 nm in open control, indicating its potential application as a precise finger or knife actuator in surgical robots. This work is of great guiding significance for future actuator designs using the methodology of ordered structure with piezoceramic actuation units and AGQSM.

Trajectory planning and motion control of full-row seedling pick-up arm

Frequent start-stops of automatic seedling transplanters would lengthen the seedling picking time due to alternating movement of the motor, and cause positioning errors and frequent motor vibrations when starting the machine. To solve these problems and ensure the pick-up continuity of automatic transplanters, in this study the smooth circular arc interpolation algorithm and the least square method for multinomial curve fitting were used to conduct the trajectory planning of automatic transplanter based on the movement of the pick-up arm of the transplanter. Velocity and time curves were fitted in segments to acquire motion control parameters and further tracking control was conducted. The mathematical model of the control system was established using Simulink, and simulation analysis and system debugging test were performed. Experiments show that the trajectory curves obtained by MATLAB’s data processing can realize the continual and smooth motion trajectory of the pick-up arm; stepper motor velocity control can effectively track the planning curve and improve the seedling pick-up efficiency. The pick-up and pushing time of each motion of the planned plug seedling transplanter reduced by 1.0678 s and the start-stop times reduced from 6 to 1, which solved the frequent motor vibrations when starting the machine and improved the stability of the system. In addition, overstep and out-of-step of the motor at the start-stop moment were avoided and displacement error was reduced. Keywords: trajectory planning, motion control, motion trajectory simulation, transplanter, stepper positioning DOI: 10.25165/j.ijabe.20201303.5264 Citation: Ren L, Wang N, Cao W B, Li J Q, Ye X C. Trajectory planning and motion control of full-row seedling pick-up arm. Int J Agric & Biol Eng, 2020; 13(3): 41–51.

Temperature field evolution and heat transfer during continual local induction cladding

The evolution of temperature field of the continual motion induction cladding and the depth of heat affected zone are studied in this study. A three-dimensional finite element model for the point type continual induction cladding is established to investigate temperature distributions of fixed and motion induction cladding modes. The novel inductor is designed for cladding of curved surfaces. The modeling reliability is verified by the temperature measurements. The influence of process parameters on the maximum temperature and the generation and transfer of heat are studied. Quantitative calculation is performed to its melting rate to verify the temperature distribution and microstructures. The results show that a good metallurgical bond can be formed between the cladding layer and substrate. The melting rate gradually falls from the top of the cladding layer to the substrate, and the grain size in the substrate gradually rises. The heat affected zone is relatively small compared to integral heating.

Influence of Sediment Mobility on Universal von Kármán Coefficient k and Traversing Length of Eddy in Fluvial Streams

Sediment mobility in stream corroborates many significant mechanisms in terms of interactions of transported particles in the carrier fluid flows. In general, the sediment entrainment in stream refers to temporal and continual motion of non-cohesive grains. This phenomenon significantly influences the near-bed turbulent flow characteristics in streams. Laboratory experiments were conducted in a rectangular open-channel flume of 15 m long, 0.90 m wide and 0.75 m deep fitted with side glass walls and the study is concerned with the determination of von Karman coefficient with non-cohesive bed-load to strive the eddy traversing length, sizes and TKE dissipation rate close to the bed. Two modes of experimental conditions are considered: (1) immobile-bed with no sediment transport known as clear-water flows; and (2) continuous weak bed-load sediment transport, without bed-forms development refer to a mobile-bed flows. In both cases, the sediment beds should remain flat and hydraulically rough. The experimental result reveals that the von Karman coefficient goes down in the traditional log-law of wall in mobile-bed streams with respect to the flow over an immobile bed. A close observation in sediment mobility due to bed load transport shows the reduction in traversing length of an eddy and increment in near-bed eddy size. The increment in near-bed eddy sizes are attributed to the reduction in turbulent kinetic energy dissipation rate close to the stream bed.

Trajectory planning and motion control of full-row seedling pick-up arm

Frequent start-stops of automatic seedling transplanters would lengthen the seedling picking time due to alternating movement of the motor, and cause positioning errors and frequent motor vibrations when starting the machine. To solve these problems and ensure the pick-up continuity of automatic transplanters, in this study the smooth circular arc interpolation algorithm and the least square method for multinomial curve fitting were used to conduct the trajectory planning of automatic transplanter based on the movement of the pick-up arm of the transplanter. Velocity and time curves were fitted in segments to acquire motion control parameters and further tracking control was conducted. The mathematical model of the control system was established using Simulink, and simulation analysis and system debugging test were performed. Experiments show that the trajectory curves obtained by MATLAB’s data processing can realize the continual and smooth motion trajectory of the pick-up arm; stepper motor velocity control can effectively track the planning curve and improve the seedling pick-up efficiency. The pick-up and pushing time of each motion of the planned plug seedling transplanter reduced by 1.0678 s and the start-stop times reduced from 6 to 1, which solved the frequent motor vibrations when starting the machine and improved the stability of the system. In addition, overstep and out-of-step of the motor at the start-stop moment were avoided and displacement error was reduced. Keywords: trajectory planning, motion control, motion trajectory simulation, transplanter, stepper positioning DOI: 10.25165/j.ijabe.20201303.5264 Citation: Ren L, Wang N, Cao W B, Li J Q, Ye X C. Trajectory planning and motion control of full-row seedling pick-up arm. Int J Agric & Biol Eng, 2020; 13(3): 41–51.

Preservation of organic carbon during active fluvial transport and particle abrasion

Abstract Oxidation of particulate organic carbon (POC) during fluvial transit releases CO2 to the atmosphere and can influence global climate. Field data show large POC oxidation fluxes in lowland rivers; however, it is unclear if POC losses occur predominantly during in-river transport, where POC is in continual motion within an aerated environment, or during transient storage in floodplains, which may be anoxic. Determination of the locus of POC oxidation in lowland rivers is needed to develop process-based models to predict POC losses, constrain carbon budgets, and unravel links between climate and erosion. However, sediment exchange between rivers and floodplains makes differentiating POC oxidation during in-river transport from oxidation during floodplain storage difficult. Here, we isolated in-river POC oxidation using flume experiments transporting petrogenic and biospheric POC without floodplain storage. Our experiments showed solid phase POC losses of 0%–10% over ∼103 km of fluvial transport, compared to ∼7% to >50% losses observed in rivers over similar distances. The production of dissolved organic carbon (DOC) and dissolved rhenium (a proxy for petrogenic POC oxidation) was consistent with small POC losses, and replicate experiments in static water tanks gave similar results. Our results show that fluvial sediment transport, particle abrasion, and turbulent mixing have a minimal role on POC oxidation, and they suggest that POC losses may accrue primarily in floodplain storage.

Theoconomy: Fixing the forecasting error

Most of the economic wealth accumulated by humans over all the ages is founded on an error of judgement or a delusion that to acquire wealth, possessions and status will bring permanent happiness. It is this deception which rises and keeps the economic household in continual motion. Founded on this delusion, humanity has created cities as well as common wealth, and invent and improve all the sciences and arts which ennoble and embellish human life. This delusion is also the cause of half of the world’s problems such as the unrelenting demand on the earth’s resources, pollution, world wars, et cetera. It is because of this delusion that the modern age is caught up in the philosophy of futility, fetishism of commodities and conspicuous consumption. This can no longer be tolerated. A new narrative ought to be found. Humans have to change their positions. A greater degree of mindfulness and consciousness are required. In this article, the nature and character of this deception in terms of Adam Smith’s universe of capitalism is expounded and a new narrative, theoconomy , is introduced to correct the error of judgement by humans.

Mooring Experimental Study of Motion Response for Pendulum Wave Energy Converters

Wave Energy Converters (WECs) is the type of Ocean energy need continual motion while operation for producing steady electricity. The mooring configuration as the answer for making sustainable WECs during operational life on the rough sea. The authors are researching trimaran pontoon of pendulum WECs type with anchors and four cables of mooring. The purpose of this research to determine the heave, pitch, and roll response from the pontoon. In this research, there are variations of wave height and wave periods. Experiment located at hydraulics laboratory in regular wave condition. The scale-up of the pontoon is (1:10) compared to real dimension. IMU (Inertial Measurement Unit) sensor used in this experiment to detect pontoon motion. Pontoon has the optimum condition at wave periods at 0.6s and height 0.4 m. Heave motion best displacement is 0.372m, Roll motion value is 1.425 degree and Pitch is 4.6164 degree. The pontoon needs fairlead for placed the mooring cables.

A self-sustained soft actuator able to rock and roll.

A triangular shaped liquid crystal network is shown to undergo a continual, rocking chair-like oscillatory chaotic motion upon exposure to a surface of constant temperature. With the addition of an azobenzene chromophore, dual response is achieved, extending the actuation freedom towards a film that shows rocking and rolling motion.

The life-cycle of Riemann–Silberstein electromagnetic vortices

To study the singularities of a monochromatic electromagnetic wave field in free space, it is desirable to use a quantity that combines both the electric field E and the magnetic field B in equal measure. The Riemann–Silberstein (R–S) field is a way of doing this. It is based on the real physical E and B and one constructs from them the complex vector field Then, one constructs and studies the optical vortices of this R–S complex scalar field. Unlike the better-known and much studied optical vortices of a monochromatic complex scalar field, which are stationary, these vortices are normally in continual motion; they oscillate at the optical frequency. We study their life cycle in the simplest model that is sufficiently generic, namely, fields generated by the interference of four randomly chosen plane elliptically polarised waves. The topological events in the life cycle do not repeat on a 3D space lattice in a stationary laboratory frame. In space–time, however, the R–S vortices are invariant under any Lorentz transformation, and because of this and the inherent time repetition there is a particular moving frame in space–time, reached by a Lorentz transformation, where there exists a repeating pattern of events in space. Its 4D unit cell constitutes, in effect, a description of the whole infinite pattern. Just because they are in constant motion, it is not surprising that the R–S vortex lines in the model make reconnections and appear as rings that either shrink to nothing or appear from nothing. However, these processes occur in groups of four, reflecting the fact that the unit cell is face-centred. What distinguishes the R–S field from the other complex scalar fields containing vortices is the existence of this face-centred repeating cell.