Objects In Three-dimensions Research Articles

Three-dimension object detection and forward-looking control strategy for non-destructive grasp of thin-skinned fruits

The dynamic non-destructive grasp of thin-skinned fruits using flexible robotic hands, which requires obtaining three-dimension(3D) spatial structure information along with adaptive planning and motion control toward the target object, is a challenging topic in agricultural intelligence. To tackle the issue of 3D detection, we utilize RGB images and LiDAR point clouds for feature extraction and construct a multi-modal depth fusion convolution neural network (MDF-CNN) to obtain the classification information and perform image segmentation. Incorporating the advantages of a variable palm structure, we establish an evaluation mechanism of the optimal grasping stability (EM-OGS) using a hybrid method of the best configuration and force closure to build a new comprehensive performance optimal configuration planning (CPO-CP) method that is based on the multiple grasping performance indexes. We also create three cross-related nonlinear prediction models P-MGF, P-ODAP, and P-OBA along with a forward-looking non-destructive grasp control algorithm (FL-NGCA) using minimum grasping force to grasp thin-skinned fruits. The control algorithm carries out online, self-directed learning in the actual grasping process of the flexible hand and constantly optimizes the accuracy of the prediction model. Experimental results show that our proposed approach greatly improves the flexible hand comprehensive performance of grasping, outperforming state-of-the-art methods for non-destructive grasping of delicate fruits in most areas.

HUMAN BODY CAD MODELING IN THE FORM OF A VARIABLE DENSITY OBJECT

High rates of technological progress contribute to the development and improvement of all spheres of human activity, including biomechanical research. The development of new prostheses, orthoses and exoskeletons place increased demands on the determination of the mass-inertial characteristics of the human body. The paper analyzes the existing experimental-analytical and analytical methods for determining the center of gravity of the human body, which are based on the segmentation method. It is shown that the existing analytical methods do not provide complete information about the individual characteristics of the modeled object, when it is implemented using CAD tools, but give only generalized results without taking into account the physical development, health status and other individual characteristics. An improvement of the analysis technique is proposed, which allows increasing the accuracy of determining the mass-inertial characteristics of the human body (including the center of gravity) by its individual anthropometric parameters on the basis of a 14-segment biomechanical model. The article presents a block-diagram and description of the corresponding software module of the calculation, implemented in the Autodesk Inventor environment, in which the human body, when determining its center of gravity, is represented as a complex three-dimension object. This object consists of elements of different densities, while the data on the density of the constituent parts are obtained on the basis of the individual characteristics of the design object by interpolating information from external specialized databases. A comparative analysis of determining the coordinates of the center of gravity of a biological object using both the existing analytical and experimental-analytical segmentation techniques, and the proposed one is carried out. It is shown that the results obtained using the proposed improved analytical technique implemented in CAD, correlate very well with the results of the existing experimental analytical technique with a deviation of 3...4 %.

The neuropsychological profile of professional action video game players.

In the past 20 years, there has been growing research interest in the association between video games and cognition. Although many studies have found that video game players are better than non-players in multiple cognitive domains, other studies failed to replicate these results. Until now, the vast majority of studies defined video game players based on the number of hours an individual spent playing video games, with relatively few studies focusing on video game expertise using performance criteria. In the current study, we sought to examine whether individuals who play video games at a professional level in the esports industry differ from amateur video game players in their cognitive and learning abilities. We assessed 14 video game players who play in a competitive league (Professional) and 16 casual video game players (Amateur) on set of standard neuropsychological tests evaluating processing speed, attention, memory, executive functions, and manual dexterity. We also examined participants’ ability to improve performance on a dynamic visual attention task that required tracking multiple objects in three-dimensions (3D-MOT) over five sessions. Professional players showed the largest performance advantage relative to Amateur players in a test of visual spatial memory (Spatial Span), with more modest benefits in a test of selective and sustained attention (d2 Test of Attention), and test of auditory working memory (Digit Span). Professional players also showed better speed thresholds in the 3D-MOT task overall, but the rate of improvement with training did not differ in the two groups. Future longitudinal studies of elite video game experts are required to determine whether the observed performance benefits of professional gamers may be due to their greater engagement in video game play, or due to pre-existing differences that promote achievement of high performance in action video games.

Swimming force characterizations of multistaged bi-helical microswimmer and 3D vortex trap manipulation

Vortex trap manipulation of microscopic objects in three-dimensions by helical microswimmers has a great potential towards non-contact biological cell manipulation or microassembly. However, in the current state-of-the-art, it has been limited in 2D manipulation due to the conflicting characteristics of optimizing the trapping force and propulsion force. In this paper, we propose a new design of the helical microswimmers enabling purely non-contact, selective and 3D vortex trap micromanipulation. The proposed helical microswimmers are fabricated by 3D nanoprinting technology based on two-photon laser absorption. The vertically standing helical mirostructures on top of the supporting micropillars allows uniform coating of ferromagnetic metal layer with minimum shadow area during metallization by sputtering. Furthermore this reduces the risk of damaging or losing materials during micromanipulation process for releasing them after fabrication which allows propulsion force characterizations and optimization. We characterized to reveal their propulsion force and this proved the propulsion force was recovered back to even higher than the single helical microswimmers. We consider that the proposed helical microswimmers with 3D manipulation could have a great impact to non-contact biological cell manipulation.

Designing Android-Based Augmented Reality Application on Three Dimension Space Geometry

Augmented reality (AR) technology is a visual technology that combines virtual world objects into real world views in real time. By utilizing augmented reality technology on an android smartphone, a geometry object of space can be visualized concretely through three-dimension virtual modeling that is similar to the original object. This research incorporates AR technology into 3dimension space geometry objects and then it is implemented in three dimension objects lectures for cadets of Ship Machinary Study Program. The purpose of this research is to find out: how the cadets response in using the AR application. This application is an application that runs on the android mobile platform, where the AR application requires video streaming taken from a smartphone camera as an input source, then this application will detect markers using a tracking system, after the markers have been detected, the object model in the geometry of the space will appear above the marker as if the object model is real. The methods or stages in designing this application use the Prototype Model, whereas the implementation of the application uses a one-group pretest-posttest design pattern. The results showed that the use of the AR application on the Android platform was able to get a positive response from cadets in lecturing the Concept of Geometry Course, especially three-dimension objects.

A Review of Process Parameters That Effect to Extrusion on Demand

An additive Manufacturing (AM) process has been introduced to fabricate three-dimension objects from liquid polymers and powder particles e.g. polymers and metals, this process has been also applied to fabricate three-dimension ceramic objects called paste materials which compose of liquid and solid components. To build additive model, the paste material is extruded via pressure force through the nozzle by using ram extrusion, then the model is constructed layer-by-layer on the table to form designed shape. To improve a capability of extrusion process, the Extrusion On Demand (EOD), that refers to the ability of paste extrusion to regulate start and stop, has been developed to improve an accuracy of material deposition. This paper presents a review of process parameters that effect to extrusion on demand such as ram velocity, Dwell time, paste property and extrusion mechanisms.

The Design of a Cylindrical Cam Structure whose Profile could be Reconstructed

Traditional cam profile curve is not changeable after it is made. So it can’t meet the requirement when the follower needs to change the motion within a short time. Therefore, we designed a new cylindrical cam structure whose profile curve could be reconstructed by adjust inserted depth of the chips. We built its three-dimension object model by SOLIDWORKS and explained its advantages and shortcomings. We illustrated its advantages by provided an example of application. And results show the new cam structure is high versatility and convenient to realize the needs of different follower motion by reconstruct its profile.

Breaking the Crowther limit: Combining depth-sectioning and tilt tomography for high-resolution, wide-field 3D reconstructions

To date, high-resolution (<1 nm) imaging of extended objects in three-dimensions (3D) has not been possible. A restriction known as the Crowther criterion forces a tradeoff between object size and resolution for 3D reconstructions by tomography. Further, the sub-Angstrom resolution of aberration-corrected electron microscopes is accompanied by a greatly diminished depth of field, causing regions of larger specimens (>6 nm) to appear blurred or missing. Here we demonstrate a three-dimensional imaging method that overcomes both these limits by combining through-focal depth sectioning and traditional tilt-series tomography to reconstruct extended objects, with high-resolution, in all three dimensions. The large convergence angle in aberration corrected instruments now becomes a benefit and not a hindrance to higher quality reconstructions. A through-focal reconstruction over a 390 nm 3D carbon support containing over 100 dealloyed and nanoporous PtCu catalyst particles revealed with sub-nanometer detail the extensive and connected interior pore structure that is created by the dealloying instability.

Analysis of EEG Activities of Middle School Students in the Process of Imagination of a Three-dimension Object

Analysis of EEG Activities of Middle School Students in the Process of Imagination of a Three-dimension Object

SnAM: a simulation software on serial manipulators

The solution of kinematics problems for serial manipulators is fundamental for their synthesis, analysis, simulation, and computer control; for this reason, this paper introduces a public domain package and open software called SnAM (Serial n-Axis Manipulators), which is developed under the ADEFID (ADvanced Engineering soFtware for Industrial Development) framework, where the manipulator is conceptualized as a derived class from CRobokin, CMachine and CIpiSModel, which are fundamental ADEFID classes. SnAM has been developed with efficient algorithms in a closed-loop solution to solve direct kinematics, whereas for the case of inverse kinematics, matrix formulation, elimination and numerical methods are implemented. Furthermore, for the architecture definition, the user is able to display a dialog box in which the design parameters are set based on the Denavit–Hartenberg convention with the aid of sliding bars, while the solid model is updated simultaneously showing the actual configuration. Since ADEFID provides tools to graphical interface with embedded control components SnAM adopt them to not only simulate virtually, but also with an adaptive prototype designed for this purpose. Furthermore, SnAM assists the user in tasks related to trajectory planning, collision-avoidance and three-dimension objects scanning.

A Study of the Roentgenologic Appearance of the Lobes of the Lung and the Interlobar Fissures

ROENTGENOGRAMS consist of superimposed shadows of a three-dimension object projected on a flat plane. The shadows obtained on the film are of two dimensions and do not give a true picture of the shape of the process or its location. To bring out the third dimension, stereo-roentgenograms are often taken. The use of postero-anterior and lateral projections gives us two films in planes at right-angles to each other, which is of great aid in studying the position and shape of the parts under consideration. The necessity of knowing the exact position and shape of a disease process is especially important in the chest. Processes occurring in the interlobar septa offer particular difficulty in interpretation on a single postero-anterior projection. Because of the oblique position of the septa, the horizontal ray projects the shadow of the septa on the roentgenogram as a broad surface, giving the impression of a diffuse area of lung involvement. Stereo-roentgenograms do not bring out the true nature or location of this process. A lateral view, in the same plane as the interlobar fissure, gives us a totally different conception as to the limits of the process. No longer should roentgenologists be satisfied to make a diagnosis of shadows of increased density occupying the upper or lower part of the chest. With the demand for information made by the chest surgeon, roentgenologists are called upon to be more accurate in locating the disease process, as well as to be more specific regarding its nature. Considerable literature has appeared concerning the roentgenologic appearance of certain disease processes, but there is no satisfactory study available as a guide to the exact appearance on the roentgenogram of the lobes of the lung and the interlobar septa. This study was undertaken to provide such a set of diagrams, showing the appearance of the lobes of the lung and interlobar septa in the postero-anterior and lateral views. The shadows obtained were subsequently compared to clinical cases of unquestioned diagnoses. We do not mean to imply that all disease processes affecting these divisions of the lung would occupy the areas designated in the diagrams: previous disease conditions of the lung may have resulted in retraction, distortion, or displacement of the region of the lung under consideration. The entire interlober septum may not be, and usually is not, involved by the disease process. Likewise, only a portion of one or more lobes may be affected. Notwithstanding such factors which may play a part in the distortion of these shadows, the general configuration of the affected parts of the lung closely simulate the diagrams experimentally produced. In a previous article one of us described the roentgenologic appearance of the potential interlobar spaces. The present study is a continuation of the subject, illustrating the affected spaces by clinical cases.