Mecanismo Diseñado y Simulado Virtualmente

Objectives: To show a process to synthesize and analyze a crank mechanism oscillator function generator. Simulate it in a virtual reality environment, without losing its physical characteristic. Evaluate deviations between analytically desired and virtually obtained. Methodology: Using the analytical method described by Hartenberg and Denavit, a graphic package and an electronic spreadsheet; knowing the angle of rotation of the crank, the angular reference position of the crank, the displacement of the oscillator, the extreme values of the independent variable and the function; precision positions, link lengths, eccentricity and oscillator reference position were determined. The links were generated, the mechanism was assembled, analyzing fifteen of its positions. Of the infinite number of existing solutions, five were synthesized. For each solution that justify it, the deviation of the generated function was evaluated with respect to the desired one. Contribution: The friendly, fast, safe, accurate and parametric process was demonstrated; modifying the inputs and checking the update of the outputs, therefore it is a contribution to the scientific progress of the area.

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Hybrid generation of smooth functions by spline interpolation

SIMULATION ◽

10.1177/003754977201800503 ◽

1972 ◽

Vol 18 (5) ◽

pp. 171-177 ◽

Cited By ~ 1

Author(s):

Anil N. Kharkar ◽

George A. Coulman

Keyword(s):

Spline Interpolation ◽

Spline Approximation ◽

Smooth Approximation ◽

Smooth Functions ◽

Function Generator ◽

Formal Procedure ◽

Simple Language ◽

Independent Variable ◽

Smooth Approximation Functions

The use of sparse data in hybrid computer simula tion has been provided with a formal procedure for generating smooth approximation functions with excellent reproduction quality. The method is use ful with data records over the independent variable or where a variable diode function generator might be used. The method depends on the theory of spline functions, which provides the specified quality of "smoothness" of the reconstructed function. An analog polynomial circuit receives parameters sequentially from the digital to generate the function. Besides illustrating an efficient method for hybrid function generation, the subject of spline approximation has been introduced to simulators in a simple language.

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Chronological review of South African guidelines for residential average annual water demand with property size as independent variable

Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie ◽

10.4102/satnt.v27i4.94 ◽

2008 ◽

Vol 27 (4) ◽

pp. 240-265

Author(s):

Heinz Jacobs

Keyword(s):

South African ◽

Computer Technology ◽

Water Demand ◽

Scientific Progress ◽

Water Systems ◽

Data Sets ◽

Research Perspective ◽

Independent Variable ◽

Annual Water ◽

Pure Research

Guidelines for residential average annual water demand (AADD) based on property size were introduced to the South African Civil Engineering fraternity in about 1960, with the most recent publication of such guidelines in 2008. The AADD forms the basis of calculations performed during the design and analysis of water systems. Over the years technology has improved, scientific progress was made and demand has changed, resulting in improved and updated guidelines for AADD. Changes in the guidelines over the years could be considered to be a result of improvement– larger and more accurate data sets are nowadays analysed statistically by improved computer technology. Also, the changes are considered to be the result of scientific advances in the fields of metering, modelling and analysis of water demand. Finally, actual changes in demand occur with time. This research provides the first documented review of the chronological development of AADD guidelines in South Africa. It is noted that only two guidelines were used for relatively long periods of time. In both cases the guidelines would not compare favourably to others from a pure research perspective, but their successful application is the result of a co-ordinated educational and marketing effort. The value of a sustained guideline structure (AADD versus stand size in this case) is also underlined.

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WORKING WITH DATA IN STATISTICAL RESEARCH

East European Scientific Journal ◽

10.31618/essa.2782-1994.2021.1.71.82 ◽

2021 ◽

Vol 1 (7(71)) ◽

pp. 36-39

Author(s):

I. Kuzmin

Keyword(s):

Null Hypothesis ◽

Statistical Data ◽

Extreme Values ◽

Mean Value ◽

Type I ◽

Statistical Research ◽

Independent Variable ◽

The Mean ◽

Range Of Values ◽

Classical Hypothesis

Statistical data in most cases are described as an arithmetic mean value and a median depending on themselves, in the absence or presence of extreme values, respectively. Also, when using the classical hypothesis testing, errors of the type I (erroneous rejection of the null hypothesis of the absence of differences) and type II (erroneous acceptance of the null hypothesis) inevitably occur. Sometimes in the data, you can make the wrong choice when choosing the dependent and independent variable. The classical check does not give a complete picture of the data of the general population. Confidence intervals for a range of values for selection within a certain probability (95%). One of the modern methods for assessing the mean, mean and other measures is resampling, in particular, bootstrap (multiple generation of samples).

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Bend-Direction and Rotation Plastic Optical Fiber Sensor

Sensors ◽

10.3390/s20185405 ◽

2020 ◽

Vol 20 (18) ◽

pp. 5405

Author(s):

Demetrio Sartiano ◽

Thomas Geernaert ◽

Elena Torres Roca ◽

Salvador Sales

Keyword(s):

Light Intensity ◽

Optical Fiber ◽

Methyl Methacrylate ◽

Optical Fiber Sensor ◽

Fiber Sensor ◽

Plastic Optical Fiber ◽

Reference Position ◽

Numerical Software ◽

Intensity Changes ◽

Angle Of Rotation

A plastic filament of poly (methyl methacrylate) (PMMA) was fabricated by extrusion. The mode confinement was simulated using numerical software. The idea is to study how the light intensity changes inside the plastic optical fiber (POF) when a bending in multiple directions is applied. The results obtained from the simulation were compared to the experimental observations. The non-circular shape of the POF allows sensing a rotation applied as well. The angle of rotation was obtained processing two images of the end facet of the fiber (one with the fiber in a reference position and one with the rotated fiber), using an intensity-based automatic image registration. The accuracy in the rotation calculation was of 0.01°.

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АНАЛІТИЧНЕ ДОСЛІДЖЕННЯ ДИНАМІКИ ТИПОВИХ КУЛІСНИХ МЕХАНІЗМІВ ТЕХНОЛОГІЧНИХ МАШИН ЛЕГКОЇ ПРОМИСЛОВОСТІ

Bulletin of the Kyiv National University of Technologies and Design Technical Science Series ◽

10.30857/1813-6796.2018.3.1 ◽

2018 ◽

Vol 122 (3) ◽

pp. 9-18

Author(s):

В. М. Дворжак

Keyword(s):

Differential Equation ◽

Computer Simulation ◽

Angular Velocity ◽

Equation Of Motion ◽

Analytical Investigation ◽

Light Industry ◽

Sewing Machine ◽

Characteristic Points ◽

Crank Mechanism ◽

Angle Of Rotation

Improving methods of designing technological machines mechanisms of light industry in CAD-programs. The analytical method of vector transformation of coordinates for calculation of typical mechanisms of technological machines and a numerical method for solving differential equations are used. Mathematical models describing the functions of the position of the moving links and the characteristic points of the multi-link mechanism of the thread take-up mechanism for the sewing machine and the dynamics of its operation are obtained. Schematic modeling of the mechanism in the Mathcad program was performed. The graphs of the dependence of the angular velocity and acceleration on time and on the angle of rotation of the crank mechanism. The algorithm of numerical and analytical investigation of the dynamics of the flat six-link articulated mechanism of the thread take-up of the sewing machine is proposed on the basis of the numerical solution of the differential equation of motion of the mechanism and a computer simulation of the mechanism in the program Mathcad. Practical Value is to use the results of research in kinematic and dynamic study of the target sewing machine mechanisms.

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Replications can cause distorted belief in scientific progress

Behavioral and Brain Sciences ◽

10.1017/s0140525x18000584 ◽

2018 ◽

Vol 41 ◽

Cited By ~ 2

Author(s):

Michał Białek

Keyword(s):

Real World ◽

Scientific Progress ◽

The Public ◽

Psychological Science

AbstractIf we want psychological science to have a meaningful real-world impact, it has to be trusted by the public. Scientific progress is noisy; accordingly, replications sometimes fail even for true findings. We need to communicate the acceptability of uncertainty to the public and our peers, to prevent psychology from being perceived as having nothing to say about reality.

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Scientific progress is like doing a puzzle, not building a wall

Behavioral and Brain Sciences ◽

10.1017/s0140525x18000900 ◽

2018 ◽

Vol 41 ◽

Author(s):

Alexa M. Tullett ◽

Simine Vazire

Keyword(s):

Scientific Progress ◽

Original Research ◽

Jigsaw Puzzle ◽

Replication Research

AbstractWe contest the “building a wall” analogy of scientific progress. We argue that this analogy unfairly privileges original research (which is perceived as laying bricks and, therefore, constructive) over replication research (which is perceived as testing and removing bricks and, therefore, destructive). We propose an alternative analogy for scientific progress: solving a jigsaw puzzle.

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