scholarly journals Analytical Study of Nonlinear Vibration in a Rub-Impact Jeffcott Rotor

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8298
Author(s):  
Nicolae Herisanu ◽  
Vasile Marinca
Keyword(s):  
Nonlinear Vibration ◽  
Friction Force ◽  
Analytical Study ◽  
Analytical Approximation ◽  
Approximation Solution ◽  
State Response ◽  
Second Stage ◽  
Jeffcott Rotor ◽  
The Stability ◽  
Two Stages

The purpose of this work is to explore the nonlinear vibration of a rub-impact Jeffcott rotor. In the first stage, the motion is not affected by the friction force, but in the second stage, the motion is influenced by the normal force and the friction force. The governing equations of the rotor of this model are derived in this paper. In consequence, there appears a difference between the two stages. We establish an approximate analytical solution for nonlinear vibrations corresponding to two stages with the mention of the location of jumps. The obtained results are compared with the numerical integration results. The steady-state response and the stability of the solutions are analytically determined for the two stages. The stability of a full annular rub solution is studied with the help of the Routh–Hurwitz criterion. Effects of different parameters of the system, the saddle-node bifurcation (turning points) and the Hopf bifurcation are presented. The main contribution lies in the analytical approximation solution based on the Optimal Auxiliary Functions Method.

scholarly journals Adaptation of the PASS Questionnaire on Russian sample

2015 ◽  
Vol 20 (1) ◽  
pp. 79-84 ◽  
Author(s):  
M.V. Zvereva
Keyword(s):  
Personality Traits ◽  
Frequency Distribution ◽  
Fixed Number ◽  
Men And Women ◽  
Second Stage ◽  
Number Of Factors ◽  
Normal Frequency ◽  
The Stability ◽  
Two Stages ◽  
Questionnaire Adaptation

We present the results of the PASS questionnaire adaptation on the Russian sample. The description of the PASS and differences from the original version are provided. The study was conducted in two stages. The first stage involves the allocation of a fixed number of factors – causes of procrastination and personality traits of a procrastinator, and the allocation of the normal frequency distribution of procrastination in the Russian-speaking population. The second stage involves checking the stability of selected factors with the test-retest studies with 30 days delay. The first stage of the study involved 148 subjects, the second stage - 31 subjects. Subjects in both groups were men and women aged 18 to 25 years with at least completed secondary education. Fixed factors of procrastination causes and personality traits of procrastinators were found in the first group of subjects. In the second group of subjects, these data have been verified by test-retest.

Quadrotor Position Control Using Cascaded Adaptive Integral Backstepping Controllers

2014 ◽  
Vol 565 ◽  
pp. 98-106 ◽  
Author(s):  
Younes Al Younes ◽  
Ahmad Drak ◽  
Hassan Noura ◽  
Abdelhamid Rabhi ◽  
Ahmed El Hajjaji
Keyword(s):  
Position Control ◽  
Control Technique ◽  
Test Results ◽  
Model Uncertainties ◽  
Second Stage ◽  
Integral Action ◽  
Modeling Errors ◽  
The Stability ◽  
Adaptation Law ◽  
Two Stages

This paper proposes a nonlinear control technique to control the position of the Qball-X4 quadrotor using a cascaded methodology of two Adaptive Integral Backstepping Controllers (AIBC). The nonlinear algorithm uses the principle of Lyapunov methodology in the backstepping technique to ensure the stability of the vehicle, and utilizes the integral action to eliminate the steady state error that caused by the disturbances and model uncertainties, as well as, the adaptation law will estimate the modeling errors caused by assumptions in simplifying the complexity of the quadrotor model. The algorithm goes through two stages of cascaded AIBCs; the first stage aims to stabilize the attitude and the altitude of the quadrotor, and the second stage feeds the first stage with the desired attitude values to control the position of the quadrotor.Flight test results show that the proposed algorithm is capable of controlling the position of the nonlinear quadrotor model.

Stability and Stationary Response of a Skew Jeffcott Rotor With Geometric Uncertainty

2007 ◽  
Author(s):  
Nicolas Driot ◽  
Alain Berlioz ◽  
Claude Henri Lamarque
Keyword(s):  
Translational Motion ◽  
Dynamical Behavior ◽  
Random Parameter ◽  
Forced Response ◽  
Motion Equations ◽  
State Response ◽  
Geometric Uncertainty ◽  
Jeffcott Rotor ◽  
The Stability ◽  
Original Motion

The dynamical behavior of an asymmetrical Jeffcott rotor subjected to a base translational motion is investigated. As the geometry of the skew disk is not well defined, we introduce some randomness. This uncertainty affects a particular parameter in the time-variant motion equations. Consequently, the amplitude of the parametric excitation is a random parameter which leads us to investigate the robustness of the dynamics. The stability is first studied by introducing a transformation of coordinates (feasible in this case) making the problem simpler. Then, far away from the unstable area, the random forced steady state response is computed from the original motion equations. The Taguchi’s method is used to provide statistical moments of the forced response.

Factors Influencing the Stability of SBR Latex

1960 ◽  
Vol 33 (2) ◽  
pp. 535-544
Author(s):  
F. A. Sliemers ◽  
Bailey Bennett ◽  
P. B. Stickney ◽  
R. G. Heiligmann ◽  
H. K. J. deDecker
Keyword(s):  
Gas Phase ◽  
Polymer Concentration ◽  
Particle Growth ◽  
Polymer Particle ◽  
Degree Of Saturation ◽  
Second Stage ◽  
Initial Stage ◽  
The Stability ◽  
Static Conditions ◽  
Two Stages

Abstract The theory is proposed as a result of this work that under “static” conditions, latex destabilization proceeds through a time-dependent localized polymer-particle dehydration. This dehydration apparently occurs in two stages. In the initial stage more or less reversible aggregates are formed. This creaming is accompanied by a perceptible increase in viscosity. In the second stage the aggregates are further dehydrated and coalescence occurs. This latter process is irreversible. Evidence is presented to support the argument that the prime requirement for the dehydration and, consequently, for the destabilization of high-stability latex is the presence of a static latex surface in contact with an unsaturated gas phase. Three factors involved here are (1) surface area, (2) surface agitation, and (3) the degree of saturation of the gas phase in contact with the surface. In addition, it is shown that particle growth precedes the destabilization and that stability is influenced by a number of other factors, including (1) temperature, (2) polymer concentration, and (3) polymer-particle size, which contribute, either directly or indirectly, to the dehydration process.

scholarly journals Efficiency of banks in Malaysia: A super efficiency approach

2019 ◽  
Vol 30 (4) ◽  
pp. 442-450
Author(s):  
Maznah Mat Kasim ◽  
Razamin Ramli ◽  
Md. Azizul Baten ◽  
Jastini Mohd Jamil ◽  
Mushtaq Taleb
Keyword(s):  
Commercial Banks ◽  
Efficiency Score ◽  
Data Envelopment ◽  
Super Efficiency ◽  
Second Stage ◽  
Sbm Model ◽  
Measuring Efficiency ◽  
Dea Models ◽  
The Stability ◽  
Two Stages

The stability of the economic system of a country very much depends on its banking industry. Data Envelopment Analysis (DEA) has been applied widely for measuring efficiency of banks. Limited studies, however, have employed the radial and non-radial DEA models to evaluate efficiency of banks without considering the ranking of the fully efficient banks since those banks have the same efficiency score. Considering the weakness of the radial and non-radial DEA, this paper aims to calculate the banks efficiency of nine commercial banks in Malaysia from 2004 to 2013 by adopting the two-stage of super efficiency slack-based measure (SE-SBM) model. This model can discriminate between the efficient banks and recalculate their efficiency scores. Then, the selected banks were able to be ranked according to their final efficiency scores. Moreover, comparative analyses of the efficiency of the banks and the year-wise efficiency of the selected banks were also conducted. The methodology consists of two stages.  In the first stage the SBM model is run to classify efficient and inefficient banks. In the second stage the super efficiency model is run to rank the efficient banks obtained from the first stage by calculating their super efficiency scores. Our empirical results show that: (1) the efficiency status of the banks fluctuated over the examined period, the high number of the efficient banks is achieved in the years 2006 and 2008, while the year 2012 has the lowest number of the efficient banks. (2) the ranking of the banks fluctuated in the studied period. (3) most of the banks are inefficient in terms of their average efficiency scores. This paper has two limitations. First, the paper did not integrate undesirable output, despite it deals with non-interest income. Second, performance evaluation of Malaysian commercial banks was only compared among the Malaysian banks.

Altered Fine Structure of B Lymphocytes Correlated with Defective Terminal Differentiation

1973 ◽  
Vol 31 ◽  
pp. 386-387
Author(s):  
Dale E. Bockman ◽  
L. Y. Frank Wu ◽  
Alexander R. Lawton ◽  
Max D. Cooper
Keyword(s):  
Immune Deficiency ◽  
B Lymphocytes ◽  
Plasma Cells ◽  
Present Report ◽  
Specific Antigen ◽  
Terminal Differentiation ◽  
Second Stage ◽  
Two Stages ◽  
Deficiency Diseases ◽  
Cell Line Generation

B-lymphocytes normally synthesize small amounts of immunoglobulin, some of which is incorporated into the cell membrane where it serves as receptor of antigen. These cells, on contact with specific antigen, proliferate and differentiate to plasma cells which synthesize and secrete large quantities of immunoglobulin. The two stages of differentiation of this cell line (generation of B-lymphocytes and antigen-driven maturation to plasma cells) are clearly separable during ontogeny and in some immune deficiency diseases. The present report describes morphologic aberrations of B-lymphocytes in two diseases in which second stage differentiation is defective.

Distributed Entropy Energy-Efficient Clustering algorithm for cluster head selection (DEEEC)

2020 ◽  
Vol 39 (6) ◽  
pp. 8139-8147
Author(s):  
Ranganathan Arun ◽  
Rangaswamy Balamurugan
Keyword(s):  
Energy Efficient ◽  
Clustering Algorithm ◽  
Cluster Head ◽  
Residual Energy ◽  
Energy Utilization ◽  
Sensor Nodes ◽  
Second Stage ◽  
Energy Efficient Clustering ◽  
Two Stages ◽  
Ch Selection

In Wireless Sensor Networks (WSN) the energy of Sensor nodes is not certainly sufficient. In order to optimize the endurance of WSN, it is essential to minimize the utilization of energy. Head of group or Cluster Head (CH) is an eminent method to develop the endurance of WSN that aggregates the WSN with higher energy. CH for intra-cluster and inter-cluster communication becomes dependent. For complete, in WSN, the Energy level of CH extends its life of cluster. While evolving cluster algorithms, the complicated job is to identify the energy utilization amount of heterogeneous WSNs. Based on Chaotic Firefly Algorithm CH (CFACH) selection, the formulated work is named “Novel Distributed Entropy Energy-Efficient Clustering Algorithm”, in short, DEEEC for HWSNs. The formulated DEEEC Algorithm, which is a CH, has two main stages. In the first stage, the identification of temporary CHs along with its entropy value is found using the correlative measure of residual and original energy. Along with this, in the clustering algorithm, the rotating epoch and its entropy value must be predicted automatically by its sensor nodes. In the second stage, if any member in the cluster having larger residual energy, shall modify the temporary CHs in the direction of the deciding set. The target of the nodes with large energy has the probability to be CHs which is determined by the above two stages meant for CH selection. The MATLAB is required to simulate the DEEEC Algorithm. The simulated results of the formulated DEEEC Algorithm produce good results with respect to the energy and increased lifetime when it is correlated with the current traditional clustering protocols being used in the Heterogeneous WSNs.

Analisis Kebutuhan Petunjuk Praktikum Berbasis Keterampilan Proses Sains untuk Mencapai Kemampuan Merancang Eksperimen

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Fitriah Khoirunnisa ◽  
Friska Septiani Silitonga ◽  
Veri Firmansyah
Keyword(s):  
Core Competence ◽  
Process Skills ◽  
Learning Materials ◽  
Science Process Skills ◽  
Second Stage ◽  
The Core ◽  
The Core Competence ◽  
Two Stages ◽  
Practical Instruction ◽  
Design Experiments

Penelitian ini bertujuan menganalisis kebutuhan petunjuk praktikum berbasis Keterampilan Proses Sains (KPS) untuk mencapai kemampuan merancang eksperimen pada materi kalor reaksi kalorimetri. Penelitian dilakukan terhadap peserta didik kelas XI SMA Negeri 2 Kota Tanjungpinang. Variabel penelitian mencakup analisis kebutuhan bahan ajar dan analisis kesesuaian Kompetensi Inti (KI) dan Kompetensi Dasar (KD). Jenis penelitian yang dilakukan adalah penelitian deskriptif kualitatif. Tahapan pertama dalam penelitian ini adalah menganalisis kebutuhan bahan ajar dengan cara membandingkan dua petunjuk praktikum yang selama ini telah digunakan di sekolah tersebut, ditinjau dari aspek struktur format penulisan, aspek kreativitas, dan aspek keterampilan proses sains yang terdapat dalam petunjuk praktikum. Sehingga didapatkan kesimpulan bahwa petunjuk praktikum yang selama ini digunakan tidak memberikan kesempatan kepada peserta didiknya untuk merancang eksperimen yang telah ditentukan. Tahapan kedua yaitu menganalisis kesesuaian kompetensi inti dan kompetensi dasar, yang bertujuan untuk menentukan indikator pencapaian kompetensi (IPK) yang akan menjadi acuan dalam mengembangkan petunjuk praktikum berbasis keterampilan proses sains. Dari kedua tahapan yang telah dilakukan maka dapat disimpulkan bahwa peserta didik memerlukan petunjuk praktikum yang mampu mengonstruksi pikiran dan mengaktifkan kinerja mereka, sehingga pendekatan Keterampilan Proses Sains menjadi pilihan dalam mengembangkan petunjuk praktikum yang sesuai dengan karakteristik kurikulum 2013.   This research aims to analyze the needs of Science Process Skills based Practical Instruction to achieve the ability to design experiments on the calor of reaction. This research was done to the students of class XI SMA Negeri 2 Tanjungpinang City. Research Variable includes the analysis of the needs of the learning materials and analysis of the suitability of the Core Competence (KI) and Basic Competence (KD). The type of research conducted is descriptive qualitative research. The first stages in this research is to analyze the needs of learning materials by comparing two practical instructions that had been implementing in the school, from the aspects of the structure of writing format, creativity, and science process skills embedded in practical instructions. The conclusion of this research that current practical instructions does not give an opportunity to the participants to design determined experiments. The second stage, namely analyzing the suitability of core competence and basic competence, which aims to determine the indicators of achievement of the competencies (GPA) which will be a reference in developing process skills-based teaching instructions science. Of the two stages that has been done then it can be concluded that learners need practical instructions to construct  thinking and and their performance, so the Science Process Skills approach is an option in developing practical instruction suitable for the characteristics of the curriculum of 2013.

ESTIMATING GAS AND ROCK OUTBURST RISK ON THE BASIS OF KNOWLEDGE AND EXPERIENCE – THE EXPERT SYSTEM BASED ON FUZZY LOGIC

2014 ◽  
Vol 59 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Norbert Skoczylas
Keyword(s):  
Fuzzy Logic ◽  
Expert System ◽  
Mining Industry ◽  
Automatic Assessment ◽  
Science Field ◽  
Second Stage ◽  
Two Stages ◽  
Outburst Hazard

Abstract The Author endeavored to consult some of the Polish experts who deal with assessing and preventing outburst hazards as to their knowledge and experience. On the basis of this knowledge, an expert system, based on fuzzy logic, was created. The system allows automatic assessment of outburst hazard. The work was completed in two stages. The first stage involved researching relevant sources and rules concerning outburst hazard, and, subsequently, determining a number of parameters measured or observed in the mining industry that are potentially connected with the outburst phenomenon and can be useful when estimating outburst hazard. Then, the Author contacted selected experts who are actively involved in preventing outburst hazard, both in the industry and science field. The experts were anonymously surveyed, which made it possible to select the parameters which are the most essential in assessing outburst hazard. The second stage involved gaining knowledge from the experts by means of a questionnaire-interview. Subjective opinions on estimating outburst hazard on the basis of the parameters selected during the first stage were then systematized using the structures typical of the expert system based on fuzzy logic.

Integrated assessment and mapping of the environmental situation in the Russian Federation regions

2017 ◽  
Vol 924 (6) ◽  
pp. 6-16
Author(s):  
V.S. Tikunov ◽  
O.Yu. Chereshnia
Keyword(s):  
Russian Federation ◽  
Pollution Index ◽  
Pollution Level ◽  
Anthropogenic Pressure ◽  
Environmental Capacity ◽  
Environmental Friendliness ◽  
Second Stage ◽  
Environmental Situation ◽  
The Russian Federation ◽  
Two Stages

The article presents a methodology for a comprehensive assessment of the environmental situation in Russian Federation regions based on the pollution index and the index of the ecological tension. The evaluation was carried out in two stages. At the first stage, the degree of pollution of the atmosphere, hydrosphere and lithosphere of the regions was estimated on the basis of the emission of pollutants into the atmosphere, departing from stationary sources, the formation of solid domestic wastes (SDW) and the discharge of contaminated wastewater. Based on these three indicators, a pollution index was constructed that estimates aggregate pollution level. In the second stage, the authors made the estimation of loads generated by atmospheric emissions, solid waste and waste water discharged into the territory of each region, per capita and in relation to the environmental capacity of the economy. This allows us to take into account the area of pollution, anthropogenic pressure and environmental responsibility of the population, as well as the environmental friendliness of production. On the basis of relative indicators, the index of ecological tension was created.

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