Advances in soft grasping in agriculture

Agricultural robotics and automation are facing some challenges rooted in the high variability 9 of products, task complexity, crop quality requirement, and dense vegetation. Such a set of 10 challenges demands a more versatile and safe robotic system. Soft robotics is a young yet 11 promising field of research aimed to enhance these aspects of current rigid robots which 12 makes it a good candidate solution for that challenge. In general, it aimed to provide robots 13 and machines with adaptive locomotion (Ansari et al., 2015), safe and adaptive manipulation 14 (Arleo et al., 2020) and versatile grasping (Langowski et al., 2020). But in agriculture, soft 15 robots have been mainly used in harvesting tasks and more specifically in grasping. In this 16 chapter, we review a candidate group of soft grippers that were used for handling and 17 harvesting crops regarding agricultural challenges i.e. safety in handling and adaptability to 18 the high variation of crops. The review is aimed to show why and to what extent soft grippers 19 have been successful in handling agricultural tasks. The analysis carried out on the results 20 provides future directions for the systematic design of soft robots in agricultural tasks.Comment: Chapter 12 of the book entitled "Advances in agri-food robotics

EXPERIMENTAL AND NUMERICAL FAILURE ANALYSIS OF DEEP STEEL COLUMN SECTIONS

The availability of reliable numerical models is essential to reduce the uncertainties present in the prediction of structural behavior. Experimental studies allow the calibration and development of numerical models capable of characterizing the realistic behavior of structural elements and components until the limit state of collapse is approached. Exterior columns in perimeter steel moment-resisting frame structures that are exposed to strong earthquakes experience bending moment demands with high levels of axial load due to overturning. Deep wide flange sections can be used as exterior columns to increase the lateral stiffness of moment frames without significantly increasing the overall weight of the structure. However, experimental data on the cyclic response of deep steel wide flange sections subjected to large drift, rotation, and axial load demands are scarce. To address this need, this research presents results from an experimental program that deals with studying and quantifying the behavior of 1:8 scaled W36X652 column sections exposed to different monotonic and cyclic loading histories consisting of large drift ratios of up to 0.1 rad, rotations at the tip of the column of up to 0.1 rad, and variable levels of axial loads up to 60% (in compression) of the column axial load carrying capacity that vary between tension and compression are used. The experiments consist of quasi-static experiments and hybrid simulations. The influence of member behavior and axial load on the parameters that control the collapse of the structure was studied. Column plastic rotations from 0.012 to 0.08 rad and post-capping rotations from 0.03 to 0.37 rad were observed depending on the loading history and level of axial load. Further, numerical models of the column were calibrated utilizing the experimental results performed in this research. These models can be used for design and performance prediction of deep column section, especially valued in seismic design and assessment

Bio-inspired kinematical control of redundant robotic manipulators

Purpose – This paper aims to propose an innovative kinematic control algorithm for redundant robotic manipulators. The algorithm takes advantage of a bio-inspired approach. Design/methodology/approach – A simplified two-degree-of-freedom model is presented to handle kinematic redundancy in the x-y plane; an extension to three-dimensional tracking tasks is presented as well. A set of sample trajectories was used to evaluate the performances of the proposed algorithm. Findings – The results from the simulations confirm the continuity and accuracy of generated joint profiles for given end-effector trajectories as well as algorithm robustness, singularity and self-collision avoidance. Originality/value – This paper shows how to control a redundant robotic arm by applying human upper arm-inspired concept of inter-joint dependency

Relationship between Single Walled Carbon Nanotubes Individual Dispersion Behavior and Properties of Electrospun Nanofibers

The dispersion stability behavior of single walled carbon nanotube (SWCNT) has important effects on morphological and mechanical properties of SWCNT/polymer composite nanofibers. The effects of SWCNTs incorporation on the morphological and structural developments and the relation between this develop-ments and mechanical properties of the polyacrylonitrile (PAN) nanofibers were demonstrated. The uni-form, stable dispersion and well oriented SWCNT within the PAN matrix were achieved through using polyvinylpyrrolidone (PVP) as dispersing agent. Our data indicate that with increasing the amount of SWCNT (from 0 to 2 wt %), the average nanofiber diameter was increased from 163±19 nm to 307±34 nm. The analysis of the mechanical properties of the composite nanofibers displays that they exhibit an im-provement in the tensile strength of ∼172% from 3.93±0.45 MPa to 10.74±1.03 MPa, and the elastic modu-lus was increased by ~885% from 61.39±15.58 GPa to 605.08±65.55 GPa, as compared to the pure electro-spun nanofibers. The optimal SWCNT concentration for electrospun nanofibers with better morphological and mechanical properties is ~2 wt %. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3516

A Novel Study of Electrospun Nanofibers Morphology as a Function of Polymer Solution Properties

Electrospinning is a process of production fibers with diameters ranging from the submicron down to the nanometer size by applying a high voltage to a polymer solution. The important parameters in the morphology of electrospun polymer fibers are polymer structure, polymer solution properties, processing conditions, and ambient parameters. In the present work electrospinning of polyacrylonitrile (PAN) has been attempted to generate uniform nanofibers without beads. Electrospinning was performed at various concentrations ranging from 4 to 18 w/v%. The effects of polymer solution properties on electrospinnability of the PAN/DMF solutions have investigated. Fiber morphology was observed under a scanning electron microscopy (SEM). For the polymer electrospun from low concentration (Be4. The relationship between solution viscosity and its concentration is in the form: η 0.0205C4.16 and relation between the diameter of electro-spun the PAN nanofiber and solution concentration is in the form: d 0.0326C3.45. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3514

FIRST REPORT OF THE GENUS AETHIOPELLA HANDSCHIN, 1942 AND SPECIES FOLSOMIA INOCULATA STACH, 1947 (HEXAPODA, COLLEMBOLA) FROM IRAN

Collembola are a widespread and abundant group of arthropods with distribution all over the world. Collembola fauna is less well-known in the northern districts of Iran. This study was conducted to investigate the Collembola fauna in the forests of Mazandaran province, North Iran, during 2016. During this study, 13 genera and 9 species belonging to 6 families were found. The genus Aethiopella Handschin, 1942 and the species Folsomia inoculata Stach, 1947 are reported for the first time from Iran, with the genus Arrhopalites Börner, 1906 recorded for the first time from Mazandaran province

DOLPH: Diffusion Models for Phase Retrieval

Phase retrieval refers to the problem of recovering an image from the magnitudes of its complex-valued linear measurements. Since the problem is ill-posed, the recovery requires prior knowledge on the unknown image. We present DOLPH as a new deep model-based architecture for phase retrieval that integrates an image prior specified using a diffusion model with a nonconvex data-fidelity term for phase retrieval. Diffusion models are a recent class of deep generative models that are relatively easy to train due to their implementation as image denoisers. DOLPH reconstructs high-quality solutions by alternating data-consistency updates with the sampling step of a diffusion model. Our numerical results show the robustness of DOLPH to noise and its ability to generate several candidate solutions given a set of measurements

uHD: Unary Processing for Lightweight and Dynamic Hyperdimensional Computing

Hyperdimensional computing (HDC) is a novel computational paradigm that operates on long-dimensional vectors known as hypervectors. The hypervectors are constructed as long bit-streams and form the basic building blocks of HDC systems. In HDC, hypervectors are generated from scalar values without taking their bit significance into consideration. HDC has been shown to be efficient and robust in various data processing applications, including computer vision tasks. To construct HDC models for vision applications, the current state-of-the-art practice utilizes two parameters for data encoding: pixel intensity and pixel position. However, the intensity and position information embedded in high-dimensional vectors are generally not generated dynamically in the HDC models. Consequently, the optimal design of hypervectors with high model accuracy requires powerful computing platforms for training. A more efficient approach to generating hypervectors is to create them dynamically during the training phase, which results in accurate, low-cost, and highly performable vectors. To this aim, we use low-discrepancy sequences to generate intensity hypervectors only, while avoiding position hypervectors. By doing so, the multiplication step in vector encoding is eliminated, resulting in a power-efficient HDC system. For the first time in the literature, our proposed approach employs lightweight vector generators utilizing unary bit-streams for efficient encoding of data instead of using conventional comparator-based generators.Comment: 7 pages, 6 figures, Accepted to the Design, Automation and Test in Europe (DATE) Conference 202

Investigating the Prevalence of Latent Tuberculosis among Healthcare Workers of Major Hospitals of Ahvaz, Iran

Background and Objective: Healthcare and laboratory workers in hospitals have a higher exposure to hospital-acquired infections (HAIs) than the general populations. Tuberculosis (TB) infection is a common HAI that is communicated from the patients with TB admitted or hospitalized in the healthcare centres. This study aims to determinate the incidence and prevalence of latent TB infection among healthcare workers in the major Hospitals in Ahvaz, Khuzestan province, Iran.Methods: This is a case-control study conducted on healthcare workers diagnosed with TB between January 2010 to December 2017. The study population consisted of healthcare workers of the three major hospitals of Ahvaz, Khuzestan including Imam Khomeini Hospital, Golestan Hospital and Shafa Hospital. All subjects underwent Mantoux tuberculin skin test (TST) and after 48 to 72 hours the reaction was measured as the length of induration. The induration equal to or greater than 10 mm was considered as positive TB. Moreover, the subjects and controls were asked to complete a self-administered questionnaire on potential risk factors for TB.Results: Among 513 subjects, male and female subjects were respectively 186 and 327. Of all subjects, 67 subjects (male: 42; female: 25) showed positive TST (10 mm ≤ induration) and 275 subjects showed 5 mm >induration. There was a significant relationship between TST result and the workplace of the subjects. Gender showed no significant relationship with the TST result.Conclusion: All healthcare workers who are in direct contact with TB patients must undergo regular TB screening test and the workers should be trained for self-conducting TST

Fabrication of Homogeneous Multi-Walled Carbon Nanotube/ Poly (Vinyl Alcohol) Composite Nanofibers for Microwave Absorption Application

Poly (vinyl alcohol) (PVA) / sodium dodecyl sulfate (SDS) / multi walled carbon nanotubes (MWCNT) camposite nanofibers with various MWCNT contents (up to 10 wt%) were fabricated by electrospinning process and their microwave absorption properties were evaluated by a vector network analyzer in the frequency range of 8 – 12 GHz (X-band) at room temperature. The uniform, stable dispersion and well oriented MWCNT within the PVA matrix were achieved through using SDS as dispersing agent. The SEM analysis of the nanofibers samples revealed that the deformation of the nanofibers increases with increasing MWCNT concentration. Very smooth surface of the composite electrospun nanofibers even for the nanofibers with concentration of 10 wt MWCNT have been successfully prepared because of the high stability dispersion of MWCNT. It was observed that absorption microwave properties improved with increasing in the loading levels of MWCNT. Finally, the PVA/SDS/MWCNT composite nanofibers sample with the 10 wt content of MWCNT has shown the reflection loss of 15 dB at the frequency of 8 GHz. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3558