[13] **viXra:1907.0534 [pdf]**
*submitted on 2019-07-26 08:31:02*

**Authors:** Edgar Valdebenito

**Comments:** 3 Pages.

We recall some Elementary sums for Pi.

**Category:** General Mathematics

[12] **viXra:1907.0531 [pdf]**
*submitted on 2019-07-26 08:35:13*

**Authors:** Edgar Valdebenito

**Comments:** 2 Pages.

We give three series for Pi.

**Category:** General Mathematics

[11] **viXra:1907.0527 [pdf]**
*submitted on 2019-07-26 10:43:36*

**Authors:** Egger Mielberg

**Comments:** 12 Pages.

The Sense Theory is not a part of traditional mathematics. It is a new paradigm of how we can formalize complex cognitive processes of the human brain. The basis of the theory is a sense function which determines sense conformity between a set of objects or/and events and a single subject (described object/event).
The sense function has a series of unique properties that can help find associative connections between trillions different-type objects/events.
By the function, we can investigate a whole process of forming a single sense of big data set of different business or scientific events.

**Category:** General Mathematics

[10] **viXra:1907.0346 [pdf]**
*submitted on 2019-07-17 08:27:21*

**Authors:** Edgar Valdebenito

**Comments:** 3 Pages.

This note presents some formulas for Pi.

**Category:** General Mathematics

[9] **viXra:1907.0320 [pdf]**
*submitted on 2019-07-16 16:39:05*

**Authors:** Vinicius Teixeira do Nascimento, Angel Ramon Sanchez Delgado, Sergio Drumond Ventura

**Comments:** 11 Pages.

Nowadays integrated crop-livestock production systems have been presented as a viable and sustainable alternative in economic, social and environmental terms. This work develops and implements a mixed integer programming model (MIXP) that represents or simulates numerically the optimum operational conditions of an integrated crop-livestock system with no-tillage (iCLS-NT), including animal transit. For the computational implementation of the model, data on the fitness of the live weight gain of each animal of the herd considered, in each period and area of the (iCLS-NT), (confinement, pasture and annual crop), as well as marginal net income of each crop and the costs per unit of food considered. In order to test the validity of the developed mathematical model, data were randomly generated. To solve each MIXP, we used the solver INTLINPROG in the software MATLAB. Thus, after the computational implementation, it was verified that the program meets all restrictions imposed, maximizes the weight gain of each animal, provides the best selection of annual crops and minimizes feeding costs in the confinement area.

**Category:** General Mathematics

[8] **viXra:1907.0264 [pdf]**
*submitted on 2019-07-15 20:00:11*

**Authors:** Halina dos Santos Salles, Paulo Frederico Souza Lomeu, Franciane Conceição Peters, Webe João Mansur

**Comments:** 9 Pages.

In building design, the designers aim a better and safer project, regarding several structural aspects, besides the reduction of the costs of the inputs. Optimization methods can be used for this purpose without compromising structural safety. Thus, this article aims at the structural optimization by genetic algorithms of reinforced concrete 3D frames. In this study a Genetic Algorithm was developed, containing the specifications for the dimensioning of the structural elements reinforcement. The objective function is formed by the costs of concrete, molds and steel and will be minimized, according to the restrictions of NBR 6118:2014 (Concrete Structures Project - Procedure). The structural model is processed in the Ansys ® software, where discretization occurs through the finite element method, to analyze and obtain the stresses and deformations of the structure. The study consideres design variables: height of beams and columns. The results show that this methodology provided responses consistent when compared to the practice and also surprised with solutions that could be rejected by designers.

**Category:** General Mathematics

[7] **viXra:1907.0263 [pdf]**
*submitted on 2019-07-15 20:01:49*

**Authors:** Antônio Chicharo Prata Lisboa, Claudia Mazza Dias, Julio Henrique Lopes de Almeida

**Comments:** 14 Pages.

This work has the purpose of performing the Dual Cycle analysis, suitable for high rotation engines, with the objective of obtaining its Energetic and Exergetic efﬁciencies, as well as quantifying the destruction of exergy in the processes. The results are obtained through parametric studies, which allow the evaluation of the behavior of parameters of interest. The calculations are developed in an open code written in Python® with the support of libraries numpy and scipy.

**Category:** General Mathematics

[6] **viXra:1907.0262 [pdf]**
*submitted on 2019-07-15 20:04:02*

**Authors:** Wilian Jeronimo dos Santos, Rosane Ferreira de Oliveira, Marcos Bacis Ceddia, Juliana Lima de Almeida

**Comments:** 10 Pages.

The present work aimed to create a tool that can contribute to the prediction of moisture content in heterogeneous and well-drained plots of soil over a given period of time. To characterise the water balance, which is a criterion for the redistribution of water in the soil, an analogy is made to the competition model in population dynamics. This analogy can be explained by “competition” for water among the different soil compartments. The different layers “compete” with each other for water due to difference in hydraulic potential. In this sense, the model proposed is based on models of interspecific competition. Furthermore, the numerical methodology proposed is characterized to be solved more easily than the traditional and highly non-linear Richards’ equation. Numerical results were compared against simulation results from the Hydrus-1D program.

**Category:** General Mathematics

[5] **viXra:1907.0261 [pdf]**
*submitted on 2019-07-15 20:05:32*

**Authors:** Carlos Andrés Reyna Vera-Tudela

**Comments:** 12 Pages.

The Boundary Element Method transforms partial differential equations that govern the problem domain into integral equations involving only contour values after the introduction of weighting functions called fundamental solutions. When the problem studied involves internal loads, such as self weight, one must search for a solution that preserves the philosophy of the method. For this purpose, the Dual Reciprocity technique is used. This work illustrates dual reciprocity with Navier’s equation with a self-weight load term. Numerical results are presented.

**Category:** General Mathematics

[4] **viXra:1907.0216 [pdf]**
*replaced on 2019-07-17 17:09:07*

**Authors:** Colin James III

**Comments:** 3 Pages. © Copyright 2019 by Colin James III All rights reserved. Respond to author by email only: info@cec-services dot com. See updated abstract at ersatz-systems.com.

The equation of the weak duality theorem, (Ax≤b, x≥0) ≤ (A^Ty≥c, y≥0), is confirmed as tautologous. Three proofs of it in the literature are not tautologous. The equation of the strong duality theorem, (Ax≤b, x≥0) = (A^Ty≥c, y≥0), is refuted as not tautologous. These form a non tautologous fragment of the universal logic VŁ4. What follows is the weak duality theorem could just as easily exclude the “or equal to” relation to read (Ax≤b, x≥0) < (A^Ty≥c, y≥0) as the corrected weak duality theorem.

**Category:** General Mathematics

[3] **viXra:1907.0215 [pdf]**
*submitted on 2019-07-12 10:03:19*

**Authors:** John Mark Vincent

**Comments:** 5 Pages.

A new method for multi-dimensional global optimization is presented. The fundamental idea is to obtain the Chebyshev norm from a set of L_p=norms; an original extrapolation procedure is used to converge to the optimum value, which is identical to the Chebyshev norm. This allows the optima to be efficiently pin-pointed by repeatedly bisecting the domain. Estimates of computational cost indicate that the method is fast.

**Category:** General Mathematics

[2] **viXra:1907.0149 [pdf]**
*submitted on 2019-07-10 03:16:40*

**Authors:** Li xiaohong

**Comments:** 14 Pages.

Chord mathematics is a mathematical model of chord language. The main features are: octave duodecimal number system, symmetric, mirror phase, and spatial expression of chord language, also known as "chord geometry".
Chord mathematics is scattered in various disciplines related to chord language, such as musicology, chord colorology, meridian science (life expression), etc. In this paper, quantitative, number system, positive and negative, coordinate, formula, calculation method and so on are integrated and unified.
Chord language is composed of chord spectrum, with quantum, string (opening, closed string, N string), symmetry, mirroring and other physical, mathematical (geometric) characteristics, manifested in music (time expression), painting (space expression), meridian (life expression) and other disciplines, with spiritual, physical duality, it has thousands of years of accumulation of understanding, The more mature mathematical model, which can be observed and verified, should be the characteristic of the theory of everything.
Key words: chord mathematics, chord geometry, duodecimal system, discrete, symmetric, mirror image

**Category:** General Mathematics

[1] **viXra:1907.0044 [pdf]**
*submitted on 2019-07-02 08:45:44*

**Authors:** Edgar Valdebenito

**Comments:** 2 Pages.

This note presents some formulas for Pi.

**Category:** General Mathematics