Prediction of the Stability Envelope of Rotor-Bearing System

2005 ◽  
Vol 128 (2) ◽  
pp. 197-202 ◽  
Author(s):  
J. K. Wang ◽  
M. M. Khonsari
Keyword(s):  
Hopf Bifurcation ◽  
Bifurcation Theory ◽  
Trial And Error ◽  
Rotor Bearing ◽  
Trial And Error Method ◽  
The Stability ◽  
Error Method ◽  
Bearing System

A method is developed for predicting the stability envelope of a rotor-bearing system using the Hopf bifurcation theory. Results are compared to published literature obtained using a trial-and-error method.

scholarly journals PEMANFAATAN SILINDER LIMBAH TES BETON SEBAGAI DINDING PENAHAN TANAH TIPE GRAVITASI

2015 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Dimas Prasetyo Muhammad, Gerard Aponno, Suselo Utoyo
Keyword(s):  
Stability Analysis ◽  
Safety Factor ◽  
Retaining Wall ◽  
Cost Estimate ◽  
Trial And Error ◽  
Foundation Soil ◽  
Trial And Error Method ◽  
The Stability ◽  
Error Method ◽  
Horizontal Arrangement

The utilization of concrete-test-cylindrical waste was few due to it’s tendency to roll over when being stacked and the stacked form was not uniform like cubed waste. That is why the writer wants to use the cylindrical waste as a material of gravity-typed retaining wall.The purpose of this study is to find out the stability, cost, and implemention method of cylindrical waste as a material such retaining wall.The stability analysis of retaining wall made from cylindrical concrete was compared to commonly stoned retaining wall through trial and error method. The next step was to make the construction of retaining wall made from cylindrical concrete and stone to see the implemetion method and cost needed per m3.       Stability analysis results in cylindrical concrete retaining wall safe from rolling, sliding, and reaction of foundation soil. Compared to stoned retaining wall of 3,00 m tall and 1,70 m long, it has safety factor (SF) Fgl = 2.13, Fgs = 2,37, and qumax = 4,07 ton/m2  which means it is close to the FS of stoned retaining wall Fgl = 2.18, Fgs = 2,39, and qumax = 9,89 ton/m2 ; at IDR 1.012.093,74 per m3 which means it is IDR 389.553 more expensive  ; and it is of horizontal arragement.Keywords: retaining wall, concrete-test cylinder, stability, cost estimate, horizontal arrangement.

scholarly journals Analysis of the Tool Stick-Out Influence on Machining Chatter

2021 ◽  
Author(s):  
Asier Barbeito Albizu ◽  
Pedro-José Arrazola ◽  
Klaus Bonde Ørskov
Keyword(s):  
Trial And Error ◽  
Machining Processes ◽  
Stability Lobe Diagram ◽  
Workpiece Surface ◽  
Stability Lobe ◽  
Excited Vibration ◽  
Machining Chatter ◽  
Trial And Error Method ◽  
The Stability ◽  
Error Method

Increased stability in machining processes is highly desired by all machining industries when vibrations and specially chatter occur. This phenomenon is defined as a self-excited vibration that occurs due to the regeneration of waviness of the workpiece surface. In machining industry, the trend is to rely on the trial and error method or mere experience when deciding the machining spindle speeds, depths of cut and tool stick-outs, all of which are parameters directly related to chatter occurrence. Currently, the shortest possible tool stick-out is chosen by default, but literature has proven that longer stick-outs may bring some advantages when it comes to material removal rates. Aiming to prove this theory, this paper will discuss the influence of the tool stick-out on machining chatter occurrence. To that end, the effect of the tool stick-out on the modal parameters of the system, on the Stability Lobe Diagram (SLD) and on productivity will be analysed. Therefore, a number of Tap-Tests to different tool/tool-holder/stick-out combinations have been performed, in order to gather the data (FRFs and SLDs) where the analysis is based on. Last but not least, some machining tests have been conducted aiming to compare the theoretical chatter occurrence conditions, provided by the SLD, with the experimental ones. For that, two Al5083 workpieces have been slot milled under different cutting conditions, facilitating the unexpected results wherein the conclusions have been based upon.

CONTEXTUAL SUBTEXT INFORMATION OF A FOREIGN LANGUAGE TEXT: HERMENEUTIC APPROACH

2020 ◽  
Vol 2020 (30) ◽  
pp. 75-87
Author(s):  
Lidiya Derbenyova
Keyword(s):  
Foreign Language ◽  
Optimal Solution ◽  
Decision Making Process ◽  
Trial And Error ◽  
Transmission Of Information ◽  
Hermeneutic Approach ◽  
Trial And Error Method ◽  
Problems Of Translation ◽  
Error Method ◽  
Language Text

The article focuses on the problems of translation in the field of hermeneutics, understood as a methodology in the activity of an interpreter, the doctrine of the interpretation of texts, as a component of the transmission of information in a communicative aspect. The relevance of the study is caused by the special attention of modern linguistics to the under-researched issues of hermeneutics related to the problems of transmission of foreign language text semantics in translation. The process of translation in the aspect of hermeneutics is regarded as the optimum search and decision-making process, which corresponds to a specific set of functional criteria of translation, which can take many divergent forms. The translator carries out a number of specific translation activities: the choice of linguistic means and means of expression in the translation language, replacement and compensation of nonequivalent units. The search for the optimal solution itself is carried out using the “trial and error” method. The translator always acts as an interpreter. Within the boundaries of a individual utterance, it must be mentally reconstructed as conceptual situations, the mentally linguistic actions of the author, which are verbalized in this text.

The determination of units in totally real cubic fields

1960 ◽  
Vol 56 (4) ◽  
pp. 318-321 ◽  
Author(s):  
H. J. Godwin
Keyword(s):  
Trial And Error ◽  
Integral Lattice ◽  
Cubic Field ◽  
Cubic Fields ◽  
Trial And Error Method ◽  
Totally Real ◽  
Rational Integral ◽  
Fundamental Units ◽  
Error Method

The determination of a pair of fundamental units in a totally real cubic field involves two operations—finding a pair of independent units (i.e. such that neither is a power of the other) and from these a pair of fundamental units (i.e. a pair ε1; ε2 such that every unit of the field is of the form with rational integral m, n). The first operation may be accomplished by exploring regions of the integral lattice in which two conjugates are small or else by factorizing small primes and comparing different factorizations—a trial-and-error method, but often a quick one. The second operation is accomplished by obtaining inequalities which must be satisfied by a fundamental unit and its conjugates and finding whether or not a unit exists satisfying these inequalities. Recently Billevitch ((1), (2)) has given a method, of the nature of an extension of the first method mentioned above, which involves less work on the second operation but no less on the first.

MXene: a promising photocatalyst for water splitting

2016 ◽  
Vol 4 (29) ◽  
pp. 11446-11452 ◽  
Author(s):  
Zhonglu Guo ◽  
Jian Zhou ◽  
Linggang Zhu ◽  
Zhimei Sun
Keyword(s):  
Water Splitting ◽  
Trial And Error ◽  
Hydrogen Fuel ◽  
Photocatalytic Water Splitting ◽  
Arduous Task ◽  
Trial And Error Method ◽  
Error Method

Identifying suitable photocatalysts for photocatalytic water splitting to produce hydrogen fuelviasunlight is an arduous task by the traditional trial-and-error method.

scholarly journals Measuring the Deformation of a Flat Die by Applying a Laser Beam on a Reflecting Surface

2009 ◽  
Vol 424 ◽  
pp. 197-204 ◽  
Author(s):  
W. Assaad ◽  
H.J.M. Geijselaers ◽  
K.E. Nilsen
Keyword(s):  
Finite Element ◽  
Laser Beam ◽  
Extrusion Process ◽  
Trial And Error ◽  
Element Calculation ◽  
Extrusion Dies ◽  
Cheap Method ◽  
Trial And Error Method ◽  
Reflecting Surface ◽  
Error Method

The design of extrusion dies depends on the experience of the designer. After the die has been manufactured, it is tested during an extrusion process and machined several times until it works properly. The die is designed by a trial and error method which is expensive interms of time consumption and the amount of scrap. Research is going on to replace the trial pressing with finite element simulations that concentrate on material and tool analysis. In order to validate the tool simulations, an experiment is required for measuring the deformation of the die. Measuring the deformation of the die is faced with two main obstacles: high temperature and little free space. To overcome these obstacles a method is tried, which works by applying a laser beam on a reflecting surface. This cheap method is simple, robust and gives good results. This paper describes measuring the deformation of a flat die used to extrude a single U shape profile. In addition, finite element calculation of the die is performed. Finally, a comparison is performed between experimental and numerical results.

Adjustment of a Grazing Incidence Spectrometer for Maximum Resolution

1969 ◽  
Vol 23 (2) ◽  
pp. 128-132 ◽  
Author(s):  
E. Alexander ◽  
B. S. Fraenkel
Keyword(s):  
Grazing Incidence ◽  
Trial And Error ◽  
Routine Method ◽  
Maximum Resolution ◽  
Trial And Error Method ◽  
Error Method

A routine method to adjust a grazing incidence spectrometer for maximum resolution is described. The trial and error method uses as variable, the distance of the slit from the Rowland circle. Examples of resolved doublets are shown.

scholarly journals Analytical and Experimental Investigation of the Stability of the Rotor-Bearing System of a New Small Turbocharger

1987 ◽  
Author(s):  
H. R. Born
Keyword(s):  
Experimental Investigation ◽  
Dynamic Stability ◽  
Squeeze Film ◽  
Test Results ◽  
Flow Capacity ◽  
Squeeze Film Dampers ◽  
Rotor Bearing ◽  
The Stability ◽  
Turbine Design ◽  
Bearing System

This paper presents an overview of the development of a reliable bearing system for a new line of small turbochargers where the bearing system has to be compatible with a new compressor and turbine design. The first part demonstrates how the increased weight of the turbine, due to a 40 % increase in flow capacity, influences the dynamic stability of the rotor-bearing system. The second part shows how stability can be improved by optimizing important floating ring parameters and by applying different bearing designs, such as profiled bore bearings supported on squeeze film dampers. Test results and stability analyses are included as well as the criteria which led to the decision to choose a squeeze film backed symmetrical 3-lobe bearing for this new turbocharger design.

scholarly journals Directivity Enhancement in Non-Reciprocal Bandpass Filters using an Evolutionary Algorithm

2021 ◽  
Author(s):  
Prantik Dutta ◽  
Arun Gande ◽  
Gopi Ram
Keyword(s):  
Evolutionary Algorithm ◽  
Insertion Loss ◽  
Return Loss ◽  
Bandpass Filter ◽  
Trial And Error ◽  
Swarm Optimization ◽  
Lumped Element ◽  
Trial And Error Method ◽  
Error Method ◽  
Maximum Directivity

In this letter, a non-reciprocal filter with enhanced directivity is analyzed methodically and the filter parameters are optimized using an evolutionary algorithm. The return loss, insertion loss, and isolation characteristics of the filter exhibit a trade-off that makes manual tuning a trial-and-error method. The veracity of the numerical modeling is conformed by designing a 150 MHz lumped element non-reciprocal bandpass filter based on the parameters extracted using an evolutionary algorithm based particle swarm optimization (PSO). The simulated and measured results comply well with the modeling and the results exhibit maximum directivity of 28.2 dB without degradation in insertion loss (1.1 dB) and return loss (16.2 dB) within the passband. The algorithm can be utilized in designing non-reciprocal filters having different center frequencies and bandwidths.

scholarly journals Stability and Hopf Bifurcation Analysis of a Vector-Borne Disease with Time Delay

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Yuanyuan Chen ◽  
Ya-Qing Bi
Keyword(s):  
Hopf Bifurcation ◽  
Time Delay ◽  
Bifurcation Theory ◽  
Center Manifold ◽  
Local Analysis ◽  
Normal Form Theory ◽  
Form Theory ◽  
Vector Borne ◽  
The Stability ◽  
Delay Differential

A delay-differential modelling of vector-borne is investigated. Its dynamics are studied in terms of local analysis and Hopf bifurcation theory, and its linear stability and Hopf bifurcation are demonstrated by studying the characteristic equation. The stability and direction of Hopf bifurcation are determined by applying the normal form theory and the center manifold argument.

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