scholarly journals Dynamic model analysis of hydraulic support

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401882014 ◽  
Author(s):  
Enguang Guan ◽  
Huihua Miao ◽  
Peibo Li ◽  
Jihao Liu ◽  
Yanzheng Zhao
Keyword(s):  
Support System ◽  
Natural Frequencies ◽  
Hydraulic Cylinder ◽  
Limited Range ◽  
Loop Modeling ◽  
Analysis Model ◽  
Hydraulic Support ◽  
Response Characteristics ◽  
Kinematic Diagram ◽  
The Relationship

In view of the shortcomings of traditional hydraulic support system, such as poor mobility and limited range of adjustment, a new configuration with double parallelogram structure is proposed. Combining the kinematic diagram of the mechanism of the new support system and the relevant parameters of the balance moment, using the kinematic vector closed-loop modeling method and D’Alembert’s principle, the relationship equation between the generalized coordinates of the hydraulic support and the geometric position parameters is obtained, and the analysis model with plural-freedom is established. Dynamic response characteristics and natural frequencies of column hydraulic cylinder and balance hydraulic cylinder are analyzed. The results demonstrate that the natural frequencies of the improved balance hydraulic cylinder and column hydraulic cylinder have been greatly improved, and the safety performance of the hydraulic support has been greatly increased.

scholarly journals Rigid-Flexible Modal Analysis of the Hydraulic 6-DOF Parallel Mechanism

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1604
Author(s):  
Chenyang Zhang ◽  
Hongzhou Jiang
Keyword(s):  
Dynamic Model ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Natural Frequencies ◽  
Hydraulic Cylinder ◽  
Flexible Structure ◽  
Actual Performance ◽  
Experimental Platform ◽  
Response Characteristics ◽  
Dynamic Response Characteristics

In view of the problems encountered in previous hydraulic 6-DOF parallel mechanism projects, flexible modes appear that the actual natural frequencies of x and y degrees of freedom of the parallel mechanism are lower than those obtained through calculation. The phenomenon above not only decreases the dynamic response characteristics of the mechanism, but also leads to doubts about the actual performance of the mechanism. The real reason for the phenomenon above is solved in this paper. First the flexible structure of the hydraulic cylinder is analyzed and simplified, and then the dynamic model of the rigid-flexible 6-DOF parallel mechanism is established with the extended Hamilton’s principle. Finally the rigid-flexible modes are calculated with the dynamic model obtained, further analysis and verification with a simulation model and an experimental platform are also conducted. Results show that the phenomenon of the flexible modes is mainly caused by the O-rings of the step-seals of the guide sleeve and those with less elasticity should be adopted to keep the dynamic characteristics of the parallel mechanism.

scholarly journals Influential Path of Social Risk Factors toward Suicidal Behavior—Evidence from Chinese Sina Weibo Users 2013–2018

2021 ◽  
Vol 18 (5) ◽  
pp. 2604
Author(s):  
Yujin Han ◽  
He Li ◽  
Yunyu Xiao ◽  
Ang Li ◽  
Tingshao Zhu
Keyword(s):  
Risk Factors ◽  
Path Analysis ◽  
Suicide Prevention ◽  
Suicidal Behavior ◽  
Empirical Support ◽  
National Bureau ◽  
Social Risk ◽  
Analysis Model ◽  
The Relationship ◽  
Path Analysis Model

(1) Purpose: The purpose of this study was to determine suicidal risk factors, the relationship and the underlying mechanism between social variables and suicidal behavior. We hope to provide empirical support for the future suicide prevention of social media users at the social level. (2) Methods: The path analysis model with psychache as the mediate variable was constructed to analyze the relationship between suicidal behavior and selected social macro variables. The data for our research was taken from the Chinese Suicide Dictionary, Moral Foundation Dictionary, Cultural Value Dictionary and National Bureau of Statistics. (3) Results: The path analysis model was an adequate representation of the data. With the mediator psychache, higher authority vice, individualism, and disposable income of residents significantly predicted less suicidal behavior. Purity vice, collectivism, and proportion of the primary industry had positive significant effect on suicidal behavior via the mediator psychache. The coefficients of harm vice, fairness vice, ingroup vice, public transport and car for every 10,000 people, urban population density, gross domestic product (GDP), urban registered unemployment rate, and crude divorce rate were not significant. Furthermore, we applied the model to three major economic development belts in China. The model’s result meant different economic zones had no influence on the model designed in our study. (4) Conclusions: Our evidence informs population-based suicide prevention policymakers that incorporating some social factors like authority vice, individualism, etc. can help prevent suicidal ideation in China.

Research on Related Model for Urban Public Crisis Handle Mechanism

2014 ◽  
Vol 989-994 ◽  
pp. 5540-5543
Author(s):  
Yong Chang Ren
Keyword(s):  
Crisis Management ◽  
Evaluation Model ◽  
Point Of View ◽  
Theoretical Point ◽  
Analysis Model ◽  
The Public ◽  
Public Crisis ◽  
Crisis Events ◽  
Response And Recovery ◽  
The Relationship

China is in a critical period of urbanization, and various social contradictions continue to be accumulated, emerged and enlarged, so public crisis management mechanism has been highly valued by governments at all levels with the public crisis events are occurred frequently. The paper conducts study for the problems in the current urban public crisis handle mechanism. First, the evaluation model of crisis management can be researched, and crisis management can be divided into four stages to evaluate respectively, they are Reduction, Readiness, Response and Recovery; then, we should research crisis prediction model to strengthen prediction, prevention and monitoring of the crisis before the crisis happened; finally, stakeholders analysis model should be studied, and scientific analyzing the interests of the various stakeholders and the relationship among them. From the theoretical point of view, the paper carries on a study for crisis handle mechanism to provide support for improving the crisis handle level.

scholarly journals Influence of the flexibility of beams and slabs in static response and dynamic properties

2016 ◽  
Vol 9 (6) ◽  
pp. 842-855 ◽  
Author(s):  
J. R. BUENO ◽  
◽  
D. D. LORIGGIO ◽  
Keyword(s):  
Finite Element Method ◽  
Natural Frequencies ◽  
Dynamic Properties ◽  
Vibration Modes ◽  
Linear Regime ◽  
Static Response ◽  
The Finite Element Method ◽  
Standard Code ◽  
The Relationship ◽  
Brazilian Standard

Abstract This article examines numerically the flexibility influence of support beams in static response and dynamic properties of a symmetric plate formed by massive slabs of reinforced concrete in elastic linear regime, using the Finite Element Method. In the static response the variation of bending mo-ments and displacements are evaluated, which depend on the relationship between the flexibility of the slab and the beam. The evaluation of dynamic properties is held in undamped free vibration, through which the vibration modes and the values of the natural frequencies is obtained, which are compared with the limits of the Brazilian standard code for design of concrete structures. Results show that the response may show great variation due to the change in the relationship between bending stiffness of the slabs and the beams.

Three Dimensional Seismic Isolation System Using Hydraulic Cylinder

2002 ◽  
Author(s):  
Shinichiro Kajii ◽  
Naoki Sawa ◽  
Nobuhiro Kunitake ◽  
K. Umeki
Keyword(s):  
Seismic Isolation ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Hydraulic Cylinder ◽  
Seismic Load ◽  
3D Seismic ◽  
Isolation System ◽  
Response Characteristics ◽  
Seismic Motion ◽  
Hydraulic Cylinders

A three-dimensional (3D) seismic isolation system for FBR building is under development. The proposed vertical isolation system consists form hydraulic cylinders with water-based liquid and accumulators to support large vertical static load and to realize low natural frequency in the vertical direction. For horizontal isolation, laminated rubber isolator or sliding type isolator will be combined. Because the major part of the feasibility of this isolation system depends on the sealing function and durability of the hydraulic cylinder, a series of feasibility tests of the hydraulic cylinder have been conducted to verify the reliability against seismic load and seismic motion. This paper describes the specification of the seismic isolations system, seismic response characteristics and the results of the feasibility tests of the seal. This study was performed as part of a government sponsored R&D project on 3D seismic isolation.

scholarly journals The effects of age and body weight on powerlifters: An analysis model of powerlifting performance based on machine learning

2019 ◽  
Vol 18 (3) ◽  
pp. 89-99
Author(s):  
Vinh Huy Chau ◽  
Anh Thu Vo ◽  
Ba Tuan Le
Keyword(s):  
Artificial Intelligence ◽  
Machine Learning ◽  
Body Weight ◽  
Root Mean Square Error ◽  
Coefficient Of Determination ◽  
Mean Square ◽  
Analysis Model ◽  
Factors Affecting ◽  
Artificial Intelligence Algorithm ◽  
The Relationship

Abstract As a up and coming sport, powerlifting is gathering more and more attetion. Powerlifters vary in their strength levels and performances at different ages as well as differing in height and weight. Hence the questions arises on how to establish the relationship between age and weight. It is difficult to judge the performance of athletes by artificial expertise, as subjective factors affecting the performance of powerlifters often fail to achieve the desired results. In recent years, artificial intelligence has made groundbreaking strides. Therefore, using artificial intelligence to predict the performance of athletes is among one of many interesting topics in sports competitions. Based on the artificial intelligence algorithm, this research proposes an analysis model of powerlifters’ performance. The results show that the method proposed in this paper can predict the best performance of powerlifters. Coefficient of determination-R2=0.86 and root-mean-square error of prediction-RMSEP=20.98 demonstrate the effectiveness of our method.

scholarly journals Vasyl Domanytskyi’s Participation in Work of “Vik” Publishing House

2019 ◽  
pp. 21-32
Author(s):  
Bohdan Tsymbal
Keyword(s):  
Publishing House ◽  
Limited Range ◽  
Starting Point ◽  
Terminus Post Quem ◽  
Archival Documents ◽  
History Of ◽  
The Russian Empire ◽  
Relationship Of ◽  
The Relationship ◽  
Printed Sources

The paper explores the initial activity of Kyiv publishing house “Vik” and Vasyl Domanytsky’s participation in its work. The history of the publishing house has not been properly studied yet. The vast majority of sources used by the scholars contain many inconsistencies, and the existing research works don’t pay attention to the causes of the differences, but rather exacerbate the problem due to uncritical attitude to the sources. The author, therefore, focuses on three issues: 1) the time when the publishing house was founded; 2) its employees; 3) Domanytskyi’s participation in its work. Researchers date the origins of the publishing house differently, within a wide period of 1894–1897. Most of them rely on a limited range of printed sources that may contain some mistakes. Based on the crossed analysis of the ‘main’ (popular) sources with the involvement of those less popular among specialists, the author identified the causes of differences in the works of the scholars and made an attempt to explain the causes of such inaccuracies. The new archival materials not only confirmed the results of studying the printed sources but also helped to establish the earliest documented date directly related to the work of the publishing house. This date may be reasonably taken as a starting point of its history. Studying the archival documents of the censorship department allows making some assumptions about the staff of the publishing house, which although remains insufficiently studied. The list of personalities is still limited to the five most famous members of the publishing circle. The findings also help to clarify the terminus post quem of Vasyl Domanytskyi’s involvement in the work of the publishing house. The results obtained are important not only for the further study of the history of Ukrainian book printing but also for highlighting the relationship of publishers with the censorship in the Russian Empire and the work of the Kyiv “Moloda Hromada” circle. The paper explores the initial activity of Kyiv publishing house “Vik” and Vasyl Domanytsky’s participation in its work. The history of the publishing house has not been properly studied yet. The vast majority of sources used by the scholars contain many inconsistencies, and the existing research works don’t pay attention to the causes of the differences, but rather exacerbate the problem due to uncritical attitude to the sources. The author, therefore, focuses on three issues: 1) the time when the publishing house was founded; 2) its employees; 3) Domanytskyi’s participation in its work. Researchers date the origins of the publishing house differently, within a wide period of 1894–1897. Most of them rely on a limited range of printed sources that may contain some mistakes. Based on the crossed analysis of the ‘main’ (popular) sources with the involvement of those less popular among specialists, the author identified the causes of differences in the works of the scholars and made an attempt to explain the causes of such inaccuracies. The new archival materials not only confirmed the results of studying the printed sources but also helped to establish the earliest documented date directly related to the work of the publishing house. This date may be reasonably taken as a starting point of its history. Studying the archival documents of the censorship department allows making some assumptions about the staff of the publishing house, which although remains insufficiently studied. The list of personalities is still limited to the five most famous members of the publishing circle. The findings also help to clarify the terminus post quem of Vasyl Domanytskyi’s involvement in the work of the publishing house. The results obtained are important not only for the further study of the history of Ukrainian book printing but also for highlighting the relationship of publishers with the censorship in the Russian Empire and the work of the Kyiv “Moloda Hromada” circle.

scholarly journals The relationship between favorable conditions for innovation in technology parks, the innovation produced, and companies’ performance

2018 ◽  
Vol 15 (3) ◽  
pp. 286-302 ◽  
Author(s):  
Lucas Bonacina Roldan ◽  
Peter Bent Hansen ◽  
Domingo Garcia-Perez-de-Lema
Keyword(s):  
Organizational Performance ◽  
Analysis Model ◽  
Content Type ◽  
Practical Support ◽  
Proposed Model ◽  
Technology Parks ◽  
Effective Development ◽  
Favorable Conditions ◽  
The Relationship ◽  
Depth Interviews

PurposeInnovation is today considered a competitive differential for improving the performance of companies, and technology parks are seen as environments with favorable conditions for such innovation. The purpose of this study is to develop a framework for analyzing favorable conditions for innovation in technology parks, the innovations produced and organizational performance.Design/methodology/approachTo this end, the authors conducted bibliographic research and in-depth interviews with managers of companies based at the Tecnopuc Science and Technology Park, and managers of the park itself, to establish practical support for previous theoretical findings.FindingsAs a result, a framework was developed to link the favorable conditions for innovation, and organizational performance.Research limitations/implicationsThe analysis model proposed here synthesizes the contributions made by several scholars on the theme, allowing for a more detailed and integrated interpretation of the phenomenon, namely, the ways through which the effective development of innovation takes place in companies residing in technology parks and the contribution of innovation to the specific performance of companies.Practical implicationsThe use of the proposed framework can help direct park managers’ action towards those relationships or activities that prove to be ineffective in achieving desired goals.Originality/valueThe use of the proposed model in empirical surveys will allow for better understanding of the phenomenon involving the features of technology parks and their effects on innovation and the performance of companies installed there, considering that such parks allow them to access resources with lower transaction costs.

scholarly journals Modeling Study on Stiffness Characteristics of Hydraulic Cylinder under Multi-Factors

2017 ◽  
Vol 63 (7-8) ◽  
pp. 447 ◽  
Author(s):  
Hao Feng ◽  
Qungui Du ◽  
Yuxian Huang ◽  
Yongbin Chi
Keyword(s):  
Mechanical System ◽  
Volume Expansion ◽  
Hydraulic Cylinder ◽  
Experimental Results ◽  
Axial Deformation ◽  
Response Characteristics ◽  
Stiffness Model ◽  
Hydraulic Cylinders ◽  
Stiffness Characteristics ◽  
Cylinder Barrel

For a complex mechanical system driven by hydraulic cylinders, the dynamic response characteristics of the mechanical system are significantly affected by the stiffness characteristics of hydraulic cylinders. This paper comprehensively studies the impacts of various factors on the stiffness characteristics of the hydraulic cylinders, including the oil bulk modulus, the air content in the hydraulic oil, the axial deformation of the piston rod, the volume expansion of the cylinder barrel, the volume expansion of the metal pipes and the flexible hoses, and the deformation of the hydraulic cylinder sealing. By combining the theoretical analysis and the experimental results, the level of each impacting factor was quantified, and the stiffness model of the hydraulic cylinder was established. Finally, comparative analysis of the stiffness was conducted by taking the experimental hydraulic cylinder as an example; it was verified that the calculated results of the proposed hydraulic cylinder stiffness model approximated the experimental results. Compared with stiffness models presented in current literature, the average accuracy was improved by more than 15 %.

Response Characteristics of Serially Connected Semisubmersibles

1999 ◽  
Vol 43 (04) ◽  
pp. 229-240
Author(s):  
H. R. Riggs ◽  
R. C. Ertekin
Keyword(s):  
Energy Loss ◽  
Natural Frequencies ◽  
Normal Modes ◽  
Induced Response ◽  
Linear Wave ◽  
Response Characteristics ◽  
Response Modes ◽  
Wave Induced ◽  
The Impact ◽  
Large Aircraft

One design for a mobile offshore base is to link serially as many as five large semisubmersibles to form a platform long enough to support large aircraft. This paper investigates the linear, wave-induced response characteristics of serially-connected semisubmersibles. A major motivation of this study is to understand more completely the forces required to link semisubmersible modules. The impact of connector strategy and damping on the response, especially the connector forces, is investigated, and the response "modes" which contribute to the connector forces are evaluated in detail. It is shown that the response characteristics can be impacted significantly by the connection strategy, and that connector damping can be a significant source of energy loss when compared to radiation damping. The wet natural frequencies and normal modes are also determined and used to explain the response characteristics of different connection strategies. Although the analyses are based on a specific semisubmersible design, the results provide insight on how other systems of connected semisubmersibles would likely behave.

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