scholarly journals Experimental Dynamic Rigidity of an Elastic Coupling with Bolts

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 989
Author(s):  
Marilena Ghitescu ◽  
Ion-Marius Ghitescu ◽  
Sorin Vlase ◽  
Paul Nicolae Borza
Keyword(s):  
Mechanical System ◽  
Torsional Vibrations ◽  
Elastic Coupling ◽  
Metallic Elements ◽  
Circular Area ◽  
Stress Concentrators ◽  
Metallic Element ◽  
Different Types ◽  
Dynamic Rigidity ◽  
Different Shapes

The paper presents an elastic coupling with bolts and intermediary non-metallic elements, which allows for radial and axial deviation and can absorb shocks and torsional vibrations. The designed bolts have a particular shape of a circular area of a length equal to the width of the non-metallic element, a cylindrical area larger than the diameter of the cylindrical groove where the non-metallic elements are mounted, and a cylindrical area smaller than the threaded area to avoid stress concentrators and bolt breakage. The coupling represents a symmetrical piece, having two planes of symmetry. Therefore, the study of such a mechanical system can be considerably simplified considering the design and description of the repeating elements. The novelty of this coupling consists in the existence of an intermediate disc between two half-couplings (driving and driven half-coupling). The non-metallic elements with different shapes are made of different types of rubber, mounted on cylindrical bolts fixed by the driving half-coupling, transmitting the motion in both directions.

scholarly journals Research on a Rice Counting Algorithm Based on an Improved MCNN and a Density Map

Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 721
Author(s):  
Ao Feng ◽  
Hongxiang Li ◽  
Zixi Liu ◽  
Yuanjiang Luo ◽  
Haibo Pu ◽  
...  
Keyword(s):  
Grain Weight ◽  
Gaussian Kernel ◽  
Density Level ◽  
Thousand Grain Weight ◽  
Original Algorithm ◽  
Different Types ◽  
Different Shapes ◽  
Density Map ◽  
Important Basis ◽  
Adhesion Condition

The thousand grain weight is an index of size, fullness and quality in crop seed detection and is an important basis for field yield prediction. To detect the thousand grain weight of rice requires the accurate counting of rice. We collected a total of 5670 images of three different types of rice seeds with different qualities to construct a model. Considering the different shapes of different types of rice, this study used an adaptive Gaussian kernel to convolve with the rice coordinate function to obtain a more accurate density map, which was used as an important basis for determining the results of subsequent experiments. A Multi-Column Convolutional Neural Network was used to extract the features of different sizes of rice, and the features were fused by the fusion network to learn the mapping relationship from the original map features to the density map features. An advanced prior step was added to the original algorithm to estimate the density level of the image, which weakened the effect of the rice adhesion condition on the counting results. Extensive comparison experiments show that the proposed method is more accurate than the original MCNN algorithm.

A new class of isotropic generators for developing 6-DOF isotropic manipulators

Robotica ◽  
2008 ◽  
Vol 26 (5) ◽  
pp. 619-625 ◽  
Author(s):  
K. Y. Tsai ◽  
T. K. Lee ◽  
Y. S. Jang
Keyword(s):  
Reference Point ◽  
Parallel Manipulators ◽  
Geometric Constraint ◽  
Kinematic Chains ◽  
New Class ◽  
New Methods ◽  
Center Point ◽  
Different Types ◽  
Different Shapes ◽  
Straight Lines

SUMMARYDeveloping 6-DOF isotropic manipulators using isotropic generators is simple and efficient, and isotropic generators can be employed to develop serial, redundant, or parallel isotropic manipulators. An isotropic generator consists of a reference point and six straight lines. The existing generators, however, have one common geometric constraint: the reference point is equidistant from the six straight lines. Some practical isotropic designs might not be obtained due to this constraint. This paper proposes methods for developing new isotropic generators. The generators thus developed are not subject to the constraint, and the new methods allow us to specify the location of the tool center point, the size of the platform or the base, or the shape of isotropic parallel manipulators. Many new generators are presented to develop 6-DOF parallel manipulators with different shapes or different types of kinematic chains.

Ultra-trace metallic element detection in liquid samples using laser induced breakdown spectroscopy based on matrix conversion and crosslinked PVA polymer membrane

2016 ◽  
Vol 31 (8) ◽  
pp. 1622-1630 ◽  
Author(s):  
Qingyu Lin ◽  
Xiaodan Han ◽  
Jie Wang ◽  
Zhimei Wei ◽  
Kunping Liu ◽  
...  
Keyword(s):  
Laser Induced Breakdown Spectroscopy ◽  
Metallic Elements ◽  
Breakdown Spectroscopy ◽  
Liquid Samples ◽  
Metallic Element ◽  
Laser Induced Breakdown ◽  
Ultra Trace ◽  
Trace Metallic Element ◽  
Matrix Conversion ◽  
Sensitive Method

A novel, sensitive method based on crosslinked polyvinyl alcohol (PVA) was developed for determining trace-amounts of metallic elements in liquid samples using laser induced breakdown spectroscopy (LIBS).

ON GEOMETRIC AND ORTHOGONAL MOMENTS

2000 ◽  
Vol 14 (07) ◽  
pp. 875-894 ◽  
Author(s):  
JUN SHEN ◽  
WEI SHEN ◽  
DANFEI SHEN
Keyword(s):  
Pattern Analysis ◽  
Equivalence Theorem ◽  
Image Features ◽  
Shape Classification ◽  
Orthogonal Moments ◽  
Zero Crossings ◽  
Different Types ◽  
Base Functions ◽  
Different Shapes ◽  
Function Discontinuity

Moments are widely used in pattern recognition, image processing, computer vision and multiresolution analysis. To clarify and to guide the use of different types of moments, we present in this paper a study on the different moments and compare their behavior. After an introduction to geometric, Legendre, Hermite and Gaussian–Hermite moments and their calculation, we analyze at first their behavior in spatial domain. Our analysis shows orthogonal moment base functions of different orders having different number of zero-crossings and very different shapes, therefore they can better separate image features based on different modes, which is very interesting for pattern analysis and shape classification. Moreover, Gaussian–Hermite moment base functions are much more smoothed, they are thus less sensitive to noise and avoid the artifacts introduced by window function discontinuity. We then analyze the spectral behavior of moments in frequency domain. Theoretical and numerical analyses show that orthogonal Legendre and Gaussian–Hermite moments of different orders separate different frequency bands more effectively. It is also shown that Gaussian–Hermite moments present an approach to construct orthogonal features from the results of wavelet analysis. The orthogonality equivalence theorem is also presented. Our analysis is confirmed by numerical results, which are then reported.

scholarly journals Vibration Pattern Related to Transverse Cracks in Rotors

2002 ◽  
Vol 9 (4-5) ◽  
pp. 217-224 ◽  
Author(s):  
Nicolò Bachschmid ◽  
Ezio Tanzi
Keyword(s):  
Thermal Effects ◽  
Transverse Cracks ◽  
Vibration Excitation ◽  
Different Types ◽  
Vibration Pattern ◽  
Rotating Shafts ◽  
Different Shapes

A method for calculating the breathing behavior of transverse cracks of different types in rotating shafts is described. Thermal effects are included. Some results in terms of vibration excitation related to different shapes of cracks are presented.

scholarly journals Some Aspects about Theoretical Static Rigidity and Experimental Static Rigidity of a New Elastic Coupling with Cylindical Bolts and Nonmetallic Elements

2019 ◽  
Vol 16 (2) ◽  
pp. 11-19
Author(s):  
Marilena Ghiţescu ◽  
Marius Ghiţescu ◽  
Arina Modrea
Keyword(s):  
Elastic Coupling ◽  
Metallic Elements ◽  
Torque Transmission ◽  
Static Rigidity ◽  
Different Dimensions ◽  
Elastic Couplings ◽  
Elastic Elements ◽  
Mechanical Transmissions ◽  
The Way

Abstract The elastic couplings are frequently used in mechanical transmissions design, to take over the radial, axial and angular misalignments and also to take over the shocks and the overloads that could appear. In this paper is presenting some aspects about the construction of couplings with bolts using non-metallic elements, e.g. rubber, having different hardness, the elements involved in torque transmission, in this case elastic elements, having also different dimensions or forms, in the way to have a good elasticity and capacity of vibration absorbtion, determining theoretical static rigidity and experimental static rigidity of a new elastic coupling with cylindrical bolts and nonmetallic elements and compare of results for these values.

scholarly journals Better to Explain or to Testify? The Position of the Accused as a Source of Oral Evidence in a Criminal Trial in a Comparative Perspective

2021 ◽  
Vol 27 ◽  
pp. 47-77
Author(s):  
Hanna Kuczyńska
Keyword(s):  
Common Law ◽  
Criminal Trial ◽  
Comparative Perspective ◽  
Legal Systems ◽  
Anglo Saxon ◽  
Present Evidence ◽  
Different Types ◽  
Different Shapes ◽  
The Common ◽  
Oral Evidence

In this article the position of the accused as a source of personal evidence in three different European legal systems: Poland, Germany, and England, will be presented. This analysis will be oriented to understand the way of functioning of the two different models of giving statements of fact by the accused at a criminal trial. The main difference is that in the common law model of criminal trial the accused may only present evidence by testifying as a witness speaking about what happened, whereas in the continental model the accused gives a specific personal type of evidence (that in the Anglo-Saxon literature is rather described as “oral evidence”) that is known as explanations. From this differentiation several consequences arise: among others, the possibility of presenting untruthful explanations and presenting many versions of events in the continental model which have to be assessed by the judges. At the same time, the same right of the accused to silence and not to give incriminating evidence applies in both models of criminal trial – however, in two different shapes and with different types of limitations.

scholarly journals Passing through resonance of the unbalanced rotor with self-balancing device

2021 ◽  
Author(s):  
Olga Drozdetskaya ◽  
Alexander Fidlin
Keyword(s):  
Mechanical System ◽  
Stationary System ◽  
Slow Dynamics ◽  
Averaging Technique ◽  
Unbalanced Rotor ◽  
Different Types ◽  
Limited Power ◽  
Damped Systems ◽  
System Configurations ◽  
Strongly Damped

AbstractThe slow dynamics of unbalanced rotors with a passive self-balancing system are investigated considering the interaction of the mechanical system with a limited power engine. The slow dynamics equations are obtained using the averaging technique for partially strongly damped systems. Stationary system configurations, different types of nonstationary solutions while passing through resonance, and areas of stability and attraction are investigated.

scholarly journals Improving Landscape Spacious Development

2018 ◽  
Vol 7 (3.2) ◽  
pp. 463
Author(s):  
Vladyslav Tymoshevskyi ◽  
Ilona Yurko ◽  
Grigoriy Shariy
Keyword(s):  
Functional Relationship ◽  
Arable Land ◽  
Payback Period ◽  
Capital Expenditures ◽  
Geometrical Parameters ◽  
Triangular Form ◽  
Design Decisions ◽  
Land Protection ◽  
Different Types ◽  
Different Shapes

The purpose of research resulted in recommendations development for landscapes spatial and territory organization improvement, in particular, on the basis of fields geometric parameters influence analysis. The conducted researches are focused on ordering of arable land territory, having spatial and territory unfavorable conditions for management. Analysis is carried out and estimation of fields geometrical parameters influence on mechanized cultivation is provided. The scale for assessing feasibility of crop rotation separating triangular form fields into trapezoidal form workspaces was formed. Different forms triangular plots (rectangular, equilateral, isosceles, scalene) and areas (from 6 to 72 ha) are considered during the study. For a comprehensive analysis of design decisions, economic indicators were used, namely: capital expenditures, annual expenses, additional products cost. Power polynomials were used to establish trends and describe the functional relationship between the different shapes of land plots area and the annual profit, resulted expenses and payback period. They were described by equations and graphs were constructed. Unprofitable, ineffective, expedient and optimal division of the triangular different types areas into trapezoidal form workspaces are presented in the table. The obtained results can be used in land management projects development for territories spatial development, territory organization, rational use organization and land protection. 

INFLUENCE OF RIGIDITY OF ELASTIC ELEMENTS OF COUPLING COUPLINGS ON TORSIONAL VIBRATION OF SHUNTING LOCOMOTIVES DRIVES

2021 ◽  
pp. 30-35
Author(s):  
A. P. Evdokimov
Keyword(s):  
Torsional Vibration ◽  
Continued Fractions ◽  
Torsional Rigidity ◽  
Torsional Vibrations ◽  
Elastic Coupling ◽  
Elastic Elements

The results of calculations of torsional vibrations of elements of power drives of shunting locomotives with different torsional rigidity of rubbercord shells of elastic coupling couplings are presented. Based on the results obtained, the choice of rubbercord shells is justified depending on their torsional rigidity. The basis for the choice of shells is the obtained results of calculations of the resonant amplitudes of torsional vibrations by the method of continued fractions.

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