scholarly journals Monitoring of Bridge Dynamics by Radar Interferometry

2014 ◽  
Vol 12 ◽  
pp. 10-15 ◽  
Author(s):  
Imrich Lipták ◽  
Ján Erdélyi ◽  
Peter Kyrinovič ◽  
Alojz Kopáčik
Keyword(s):  
High Frequency ◽  
Slovak Republic ◽  
High Accuracy ◽  
Radar Interferometry ◽  
Discrete Fourier Transformation ◽  
Vibration Modes ◽  
Bridge Structures ◽  
Comparison Of The Results ◽  
Method Model

The paper presents the possibilities of radar interferometry in dynamic deformationmonitoring of bridge structures. The technology is increasingly used for this purposethanks to high accuracy of realized measurements and possibility to measure deformationat multiple places of the monitored structure. High frequency of realized measurements (upto 200 Hz) enables to determine the most of significant vibration modes of bridgedeformation. This technology is presented on real case study of the cycle bridge over theriver Morava near to Bratislava (Slovak republic). A spectral analysis of vibrationfrequencies is performed by discrete Fourier transformation. The evaluation of correctnessof the obtained deformation is performed by comparison of the results with accelerometerand total station measurements and FEM (Finite Element Method) model of the structure.

Case study: Simulation and control of high frequency noise for commercial vehicle cab considering leak

2019 ◽  
Vol 67 (4) ◽  
pp. 315-329
Author(s):  
Rongjiang Tang ◽  
Zhe Tong ◽  
Weiguang Zheng ◽  
Shenfang Li ◽  
Li Huang
Keyword(s):  
High Frequency ◽  
Commercial Vehicle ◽  
Frequency Noise ◽  
High Frequency Noise ◽  
Simulation And Control ◽  
And Control

scholarly journals An Improved Time Integration Method Based on Galerkin Weak Form with Controllable Numerical Dissipation

2021 ◽  
Vol 11 (4) ◽  
pp. 1932
Author(s):  
Weixuan Wang ◽  
Qinyan Xing ◽  
Qinghao Yang
Keyword(s):  
High Frequency ◽  
Integration Method ◽  
Time Integration ◽  
Low Frequency ◽  
Weak Form ◽  
High Accuracy ◽  
Numerical Dissipation ◽  
Frequency Range ◽  
Time Integration Method ◽  
Numerical Damping

Based on the newly proposed generalized Galerkin weak form (GGW) method, a two-step time integration method with controllable numerical dissipation is presented. In the first sub-step, the GGW method is used, and in the second sub-step, a new parameter is introduced by using the idea of a trapezoidal integral. According to the numerical analysis, it can be concluded that this method is unconditionally stable and its numerical damping is controllable with the change in introduced parameters. Compared with the GGW method, this two-step scheme avoids the fast numerical dissipation in a low-frequency range. To highlight the performance of the proposed method, some numerical problems are presented and illustrated which show that this method possesses superior accuracy, stability and efficiency compared with conventional trapezoidal rule, the Wilson method, and the Bathe method. High accuracy in a low-frequency range and controllable numerical dissipation in a high-frequency range are both the merits of the method.

What Kind of People Use Carsharing for Commuting? Case Study in Shanghai

2019 ◽  
Vol 2673 (5) ◽  
pp. 770-778 ◽  
Author(s):  
Jianhong Ye ◽  
Daoge Wang ◽  
Hua Zhang ◽  
Hong Yang
Keyword(s):  
High Frequency ◽  
Urban Areas ◽  
Descriptive Analysis ◽  
User Characteristics ◽  
Logistic Regression Models ◽  
Highly Educated ◽  
Suburban Areas ◽  
Commuting Mode ◽  
Study Offer

Carsharing as a service has been growing rapidly worldwide. Its expansion has drawn wide attention in the research community with regard to the underlying driving factors and user characteristics. Despite these extensive investigations, there are still limited studies focusing on the examination of users using carsharing as a commuting mode. The answers to questions such as what kind of people would like to use carsharing for commuting and why they frequently use carsharing to commute are not clear. To enrich our understanding of these problems, this paper aims to investigate carsharing commuters in a mega city. Specifically, it intends to integrate the actual user order data with survey data from 1,920 participants to uncover the characteristics of carsharing commuters. Data from the Evcard carsharing systems in Shanghai were explicitly analyzed. Through descriptive analysis and logistic regression models, the characteristics and critical factors that affect the choice of carsharing as a commuting mode were captured. The results show that: 1. carsharing commuters mostly live or work in suburban areas in which public transport accessibility is limited; 2. carsharing commuters are more likely to be highly educated, in a higher income bracket, and older than other carsharing members; 3. high-frequency carsharing commuters own a reduced number of private cars; and 4. those high-frequency carsharing commuters with higher income are less sensitive to the carsharing costs caused by congestion. The findings in the study offer some insights into carsharing commuters and provide some supportive information for considering policies in developing carsharing systems in urban areas.

scholarly journals Tackling Illegal Activities Through Tax Law – Al Capone Case Study

2015 ◽  
Vol 6 (1) ◽  
pp. 47-56
Author(s):  
Matej Kacaljak
Keyword(s):  
Criminal Law ◽  
Tax Evasion ◽  
Slovak Republic ◽  
Basic Structure ◽  
Tax Law ◽  
Legal Environment ◽  
Legal Institutions ◽  
The Usa ◽  
Illegal Activities

Abstract This paper discusses the Al Capone case and identifies legal institutions which contributed to the conviction of Al Capone for tax evasion in the USA and discusses similarities in Slovak law. The Slovak legal environment is assessed with the aim of identifying potential room for improvement. Under an assumption of identical factual circumstances, it is tested whether Al Capone would be convicted of tax evasion in the Slovak Republic and if not, what would be the main reasons. The paper concludes that due to some, probably unintentional, specifics of Slovak tax and criminal law, Al Capone could not be convicted of tax evasion by the Slovak courts. In our opinion, these specifics do not, however, constitute material elements of the basic structure of Slovak tax and criminal law and could be relatively easily corrected.

An Efficient Galerkin BEM to Compute High Acoustic Eigenfrequencies

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Mario Durán ◽  
Jean-Claude Nédélec ◽  
Sebastián Ossandón
Keyword(s):  
Numerical Method ◽  
Integral Equations ◽  
High Frequency ◽  
High Accuracy ◽  
Integral Representations ◽  
Stability And Convergence ◽  
Symmetric Matrices ◽  
Frequency Interval ◽  
Numerical Treatment ◽  
The Stability

An efficient numerical method, using integral equations, is developed to calculate precisely the acoustic eigenfrequencies and their associated eigenvectors, located in a given high frequency interval. It is currently known that the real symmetric matrices are well adapted to numerical treatment. However, we show that this is not the case when using integral representations to determine with high accuracy the spectrum of elliptic, and other related operators. Functions are evaluated only in the boundary of the domain, so very fine discretizations may be chosen to obtain high eigenfrequencies. We discuss the stability and convergence of the proposed method. Finally we show some examples.

HFTViz: Visualization for the exploration of high frequency trading data

2021 ◽  
pp. 147387162110649
Author(s):  
Javad Yaali ◽  
Vincent Grégoire ◽  
Thomas Hurtut
Keyword(s):  
Portfolio Management ◽  
High Frequency ◽  
High Speed ◽  
High Frequency Trading ◽  
Domain Experts ◽  
Risk Return ◽  
Visualization Tools ◽  
Liquidity Measures ◽  
Trading Volumes

High Frequency Trading (HFT), mainly based on high speed infrastructure, is a significant element of the trading industry. However, trading machines generate enormous quantities of trading messages that are difficult to explore for financial researchers and traders. Visualization tools of financial data usually focus on portfolio management and the analysis of the relationships between risk and return. Beside risk-return relationship, there are other aspects that attract financial researchers like liquidity and moments of flash crashes in the market. HFT researchers can extract these aspects from HFT data since it shows every detail of the market movement. In this paper, we present HFTViz, a visualization tool designed to help financial researchers explore the HFT dataset provided by NASDAQ exchange. HFTViz provides a comprehensive dashboard aimed at facilitate HFT data exploration. HFTViz contains two sections. It first proposes an overview of the market on a specific date. After selecting desired stocks from overview visualization to investigate in detail, HFTViz also provides a detailed view of the trading messages, the trading volumes and the liquidity measures. In a case study gathering five domain experts, we illustrate the usefulness of HFTViz.

Comparison of Numerical Methods for Determining Torsion Stiffness of Automotive Chassis

2011 ◽  
Author(s):  
Steven Tebby ◽  
Ebrahim Esmailzadeh ◽  
Ahmad Barari
Keyword(s):  
Finite Element Analysis ◽  
Analytical Approach ◽  
Torsional Stiffness ◽  
Design Stage ◽  
Element Analysis ◽  
Detailed Design ◽  
Vertical Displacements ◽  
Comparison Of The Results ◽  
Torsion Stiffness

The torsion stiffness of an automotive chassis can be determined using an analytical approach based purely on geometry, using an experimental method, or alternatively by employing a Finite Element Analysis (FEA) process. These three methods are suitable at different design stages and combined together could prove to be practical methods of determining the torsion stiffness of a chassis. This paper describes and compares two distinct FEA processes to determine the torsion stiffness of an automotive chassis during the detailed design stage. The first process iteratively applies forces to the model and records displacements, while the second process gradually applies vertical displacements in place of force to determine the torsional stiffness threshold. Each method is explained and supported with a case study to provide a basis of comparison of the results.

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