scholarly journals Exact Stiffness for Beams on Kerr-Type Foundation: The Virtual Force Approach

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Suchart Limkatanyu ◽  
Woraphot Prachasaree ◽  
Nattapong Damrongwiriyanupap ◽  
Minho Kwon ◽  
Wooyoung Jung
Keyword(s):  
Stiffness Matrix ◽  
Element Stiffness Matrix ◽  
Flexibility Matrix ◽  
Force Equation ◽  
Virtual Force ◽  
Proposed Model ◽  
The Matrix ◽  
Natural Element ◽  
The Individual ◽  
Interpolation Functions

This paper alternatively derives the exact element stiffness equation for a beam on Kerr-type foundation. The shear coupling between the individual Winkler-spring components and the peripheral discontinuity at the boundaries between the loaded and the unloaded soil surfaces are taken into account in this proposed model. The element flexibility matrix is derived based on the virtual force principle and forms the core of the exact element stiffness matrix. The sixth-order governing differential compatibility of the problem is revealed using the virtual force principle and solved analytically to obtain the exact force interpolation functions. The matrix virtual force equation is employed to obtain the exact element flexibility matrix based on the exact force interpolation functions. The so-called “natural” element stiffness matrix is obtained by inverting the exact element flexibility matrix. One numerical example is utilized to confirm the accuracy and the efficiency of the proposed beam element on Kerr-type foundation and to show a more realistic distribution of interactive foundation force.

Analysis of Reinforced Concrete Column Using a Beam-Column Element with a Meshed Section

2011 ◽  
Vol 255-260 ◽  
pp. 1954-1958
Author(s):  
Ling Yuan Zhou ◽  
Qiao Li
Keyword(s):  
Reinforced Concrete ◽  
Stiffness Matrix ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Beam Element ◽  
Reinforced Concrete Column ◽  
Flexibility Matrix ◽  
Stiffness Matrices ◽  
Column Element ◽  
Interpolation Functions

A efficient 3D reinforced-concrete beam element based on the flexibility method and distributed nonlinearity theory is proposed, The sections of the beam element are divided into the plane isoparametric elements in this formulation, the section stiffness matrices are calculated through the integration of stress-strain relations of concrete including reinforcing steel effect in the section. The flexibility matrices of the sections are calculated by inverting the stiffness matrices, and the element flexibility matrix is formed through the force interpolation functions. The element stiffness matrix is evaluated through the element flexibility matrix. Finally, the buckling behaviors of a reinforced concrete beam under various eccentric loads are analyzed with the proposed formulation to illustrate its accuracy and computational efficiency.

scholarly journals Shared Partisanship, Household Norms and Turnout: Testing a Relational Theory of Electoral Participation

2016 ◽  
Vol 48 (3) ◽  
pp. 807-823 ◽  
Author(s):  
Edward Fieldhouse ◽  
David Cutts
Keyword(s):  
Party Identification ◽  
Household Survey ◽  
Relational Theory ◽  
Civic Duty ◽  
Proposed Model ◽  
The Social ◽  
Empirical Tests ◽  
Partisan Identification ◽  
Consumption Benefits ◽  
The Individual

Previous research shows that the household context is a crucial source of influence on turnout. This article sets out a relational theory of voting in which turnout is dependent on the existence of relational selective consumption benefits. The study provides empirical tests of key elements of the proposed model using household survey data from Great Britain. First, building on expressive theories of voting, it examines the extent to which shared partisan identification enhances turnout. Secondly, extending theories of voting as a social norm, it tests whether the civic norms of citizens’ families or households affect turnout over and above the social norms of the individual. In accordance with expectations of expressive theories of voting, it finds that having a shared party identification with other members of the household increases turnout. It also finds that the civic duty of other household members is important in explaining turnout, even when allowing for respondent’s civic duty.

Spatio-Temporal Gaussianization Flows for Extreme Event Detection

2021 ◽  
Author(s):  
Miguel-Ángel Fernández-Torres ◽  
J. Emmanuel Johnson ◽  
María Piles ◽  
Gustau Camps-Valls
Keyword(s):  
Event Detection ◽  
Land Surface ◽  
Extreme Event ◽  
Learning Approaches ◽  
Proposed Model ◽  
Individual Contributions ◽  
Current Context ◽  
Spatio Temporal ◽  
The Individual ◽  
Anomaly Score

<p>Automatic anticipation and detection of extreme events constitute a major challenge in the current context of climate change. Machine learning approaches have excelled in detection of extremes and anomalies in Earth data cubes recently, but are typically both computationally costly and supervised, which hamper their wide adoption. We alternatively present here an unsupervised, efficient, generative approach for extreme event detection, whose performance is illustrated for drought detection in Europe during the severe Russian heat wave in 2010. The core architecture of the model is generic and could naturally be extended to the detection of other kinds of anomalies. First, it computes hierarchical appearance (spatial) and motion (temporal) representations of several informative Essential Climate Variables (ECVs), including soil moisture, land surface temperature, as well as features describing vegetation health. Then, these representations are combined using Gaussianization Flows that yield a spatio-temporal anomaly score. This allows the proposed model not only to detect droughts areas, but also to explain why they were produced, monitoring the individual contributions of each of the ECVs to the indicator at its output.</p>

scholarly journals Synthesis and Characterization of a Bioartificial Polymeric System with Potential Antibacterial Activity: Chitosan-Polyvinyl Alcohol-Ampicillin

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3109 ◽  
Author(s):  
Andres Bernal-Ballen ◽  
Jorge Lopez-Garcia ◽  
Martha-Andrea Merchan-Merchan ◽  
Marian Lehocky
Keyword(s):  
Antibacterial Activity ◽  
Polyvinyl Alcohol ◽  
Statistical Significance ◽  
Antibacterial Properties ◽  
Intermolecular Forces ◽  
Polymeric System ◽  
Bacterial Strains ◽  
Natural Polymers ◽  
The Matrix ◽  
The Individual

Bio-artificial polymeric systems are a new class of polymeric constituents based on blends of synthetic and natural polymers, designed with the purpose of producing new materials that exhibit enhanced properties with respect to the individual components. In this frame, a combination of polyvinyl alcohol (PVA) and chitosan, blended with a widely used antibiotic, sodium ampicillin, has been developed showing a moderate behavior in terms of antibacterial properties. Thus, aqueous solutions of PVA at 1 wt.% were mixed with acid solutions of chitosan at 1 wt.%, followed by adding ampicillin ranging from 0.3 to 1.0 wt.% related to the total amount of the polymers. The prepared bio-artificial polymeric system was characterized by FTIR, SEM, DSC, contact angle measurements, antibacterial activity against Staphylococcus aureus and Escherichia coli and antibiotic release studies. The statistical significance of the antibacterial activity was determined using a multifactorial analysis of variance with ρ < 0.05 (ANOVA). The characterization techniques did not show alterations in the ampicillin structure and the interactions with polymers were limited to intermolecular forces. Therefore, the antibiotic was efficiently released from the matrix and its antibacterial activity was preserved. The system disclosed moderate antibacterial activity against bacterial strains without adding a high antibiotic concentration. The findings of this study suggest that the system may be effective against healthcare-associated infections, a promising view in the design of novel antimicrobial biomaterials potentially suitable for tissue engineering applications.

Study of the Stiffness Matrix of Preloaded Duplex Angular Contact Ball Bearings

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Shengye Lin ◽  
Shuyun Jiang
Keyword(s):  
Stiffness Matrix ◽  
Degrees Of Freedom ◽  
Ball Bearing ◽  
Ball Bearings ◽  
Fixed Position ◽  
Angular Contact Ball Bearing ◽  
Face To Face ◽  
Radial Stiffness ◽  
Proposed Model ◽  
Stiffness Characteristics

This paper studies the stiffness characteristics of preloaded duplex angular contact ball bearings. First, a five degrees-of-freedom (5DOF) quasi-static model of the preloaded duplex angular contact ball bearing is established based on the Jones bearing model. Three bearing configurations (face-to-face, back-to-back, and tandem arrangements) and two preload mechanisms (constant pressure preload and fixed position preload) are included in the proposed model. Subsequently, the five-dimensional stiffness matrix of the preloaded duplex angular contact ball bearing is derived analytically. Then, an experimental setup is developed to measure the radial stiffness and the angular stiffness of duplex angular contact ball bearings. The simulated results match well with those from experiments, which prove the validity of the proposed model. Finally, the effects of bearing configuration, preload mechanism, and unloaded contact angle on the angular stiffness and the cross-coupling are studied systematically.

Thermo-kinetic investigation of heavy metal ions adsorption onto lignin considering coupled adsorption–desorption mechanisms: Modeling and experimental validation

2018 ◽  
Vol 09 (02) ◽  
pp. 1850014
Author(s):  
Farnaz Seyedvakili ◽  
Mohammad Samipoorgiri
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Individual Characteristics ◽  
Adsorption And Desorption ◽  
Isotherm Equation ◽  
Proposed Model ◽  
Isotherm And Kinetic Models ◽  
The Individual ◽  
Adsorption Desorption

A coupled adsorption–desorption thermo-kinetic model is developed incorporating both adsorption and desorption reactions. A local pseudo-equilibrium condition at the interface of adsorbent and adsorbate bulk phases was used as isotherm equation which can even be applied for multi-pollutants scenarios. The developed model is then validated using collected experimental data of heavy metal ions (Pb, Cu, Cd, Zn, and Ni). Comparisons were made for a number of isotherm and kinetic models to examine the performance of the proposed model. The developed model revealed desirable accuracy and superiority over other models in predicting the adsorption behavior and can be used for other systems of concern. The model correlates the adsorption kinetic with an [Formula: see text] value of 0.9391 and desorption kinetic with an [Formula: see text] value of 0.9383. By application of the proposed model to any available adsorption datasets, the individual characteristics of adsorption and desorption can be determined.

scholarly journals Estimating the probability of forecasted events

2016 ◽  
Vol 4 (1) ◽  
pp. 76
Author(s):  
Alexander Madera
Keyword(s):  
New Products ◽  
Error Matrix ◽  
The Matrix ◽  
The Individual

The article elaborates a method for estimating the probabilities of occurrence of prognosticated events in future. On the basis of the data from the previous periods about prognosticating the relevant events, as well as the data about the trends observed at present, two matrices are formed, the product of which is the matrix for the prognosis errors committed by the individual or the expert. The article shows that the vector for probabilities of the prognosticated events is the eigenvector of the prognosis error matrix, which corresponds to its single eigenvalue. Application of the elaborated method is shown on the definite example for forecasting demand of new products.

scholarly journals Time Coordination of Periodic Passenger Train Connections in Conditions of Single-Track Lines

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Filip Lorenz ◽  
Vit Janos ◽  
Dusan Teichmann ◽  
Michal Dorda
Keyword(s):  
Mathematical Model ◽  
Mathematical Programming ◽  
Real Data ◽  
Real Problem ◽  
Single Track ◽  
Railway Stations ◽  
Optimization Software ◽  
Proposed Model ◽  
The Individual ◽  
The Given

The article addresses creation of a mathematical model for a real problem regarding time coordination of periodic train connections operated on single-track lines. The individual train connections are dispatched with a predefined tact, and their arrivals at and departures to predefined railway stations (transfer nodes) need to be coordinated one another. In addition, because the train connections are operated on single-track lines, trains that pass each other in a predefined railway stations must be also coordinated. To optimize the process, mathematical programming methods are used. The presented article includes a mathematical model of the given task, and the proposed model is tested with real data. The calculation experiments were implemented using optimization software Xpress-IVE.

scholarly journals The Safety of Professionalization Subjects in Psychological and Neuropsychological Aspects

2021 ◽  
Vol 12 (1) ◽  
pp. 19-39
Author(s):  
Olha Lazorko ◽  
Virna Zhanna ◽  
Vasyl Yahupov ◽  
Oksana Valchuk-Orkusha ◽  
Iryna Melnyk ◽  
...  
Keyword(s):  
Professional Training ◽  
Functional Organization ◽  
Personal Characteristics ◽  
Personal Protection ◽  
Proposed Model ◽  
Security Problem ◽  
The Subject ◽  
Methodological Principles ◽  
The Individual ◽  
Graduating Students

Recently, the revision of priorities in the interpretation of the security problem and their transformation from the interests of the state to the interests of man himself, have actualized the study of psychological protection. Especially aspects of personal protection are relevant in the professional sphere, which led to the development of the problem of personal protection as a subject of professionalization, taking into account psychological and neuropsychological factors. The purpose of the study is to empirically verify the structurally functional organization of personal protection as a subject of professionalization. The proposed model is based on the methodological principles and conditions of the content of the subject, system and synergetic approaches (the subject principle determines the subjective features expressed in subjective-personal characteristics, the system principle - substantial features expressed in socially personal characteristics; the synergetic principle - quality features that are integrative sign of professional protection of the individual. The sample of the study was: graduating students (n = 180); 4th and 5th year students (n = 230); doctors and medical workers (n = 441). The characteristics of psychodiagnostic tools used in these blocks of the empirical research program are described. The results of the study demonstrated the excellent content of empirical referents of professional protection of the individual in the period of professional optation, professional training and actual professional implementation in ordinary and special conditions of activity. The scientific position of the empirical study of professional safety of the individual is realized in the separation of the experience of social satisfaction, the system-forming factor of which is the urgent need that initiates the manifestation of successful professional realization.

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