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Copyright of Formación Universitaria is the property of Centro de Informacion Tecnologica (CIT) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Góndola, Enseñanza y Aprendizaje de las Ciencias is the property of Gondola, Ensenanza y Aprendizaje de las Ciencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Uni-Pluri/Versidad is the property of Universidad de Antioquia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Social Review (2695-9755) is the property of Eagora Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present research study aims to develop a novel methodology for estimating the VKT (Vehicle Kilometers Traveled) indicator and the energy consumption according to road transport type. Calculations are made for the Province of Loja (Ecuador) for the year 2014 by using an OLADE (Latin American Energy Organization) energy balance method. This is combined with a model similar to the Hardy Cross hydraulic flow systems solution with linear equations. The transportation system is represented as an energy balance and the inputs are: total fleet and vehicle type, specific average consumption for each vehicle type, and global fuel sales. The results show that there is a 2% variation between calculated consumed energy and total dispatched energy. The total energy used is 1,123,198 BEP, of which 24.65% is for passenger transport and 66.18% for cargo transport. It is concluded that the proposed methodology is appropriate, applicable nation-wide, and replicable in other provinces. [ABSTRACT FROM AUTHOR]

Copyright of Formación Universitaria is the property of Centro de Informacion Tecnologica (CIT) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Nicolaita de Estudios Económicos is the property of Universidad Michoacana de San Nicolas de Hidalgo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tennessee Eastman plant (TEP) involves very complex process with presence of non linearity, for that it is necessary the control of important variables. In this paper a TEP model is developed. Gray box models are selected to model the process. Gray box models have advantages with respect to classic model techniques, these techniques are knowledge models and empirical models. First, models are obtained employing mass and energy balances, defining parameters and making supposed. Then, from process data and employing MatLab® software, empirical models are obtained. The combination of all models constitutes the gray box final model and the general objective of this paper. [ABSTRACT FROM AUTHOR]

In this paper, an iterative algorithm is constructed to improve the solution of a system of linear equations, of the form Ax = b, when it is solved using the Gauss-Jordan method and by using finite arithmetic. Understanding the functioning of the algorithm, showing its scope and analyzing how it is deduced, is achieved through the concept of matrix norm, together with some of its properties. The concept of the condition number of a matrix is introduced, and are found bounds for it by using the matrix norms. Finally, it is explained the iterative algorithm of the Refinement, showing the power of this one, when it is solved a system of linear equations ill conditioned. [ABSTRACT FROM AUTHOR]

The objective of the article is to present a proposal for the restructuring of the interurban transportation system of travellers by road in Aragón, based on a previous diagnosis. Several sources of information and spatial analysis methods are used. The difficulty of providing a quality transport service in regions of low population density and settlements dispersion is noted and the inefficiencies of the current system of linear concessions are identified. A new system of zonal concessions is proposed, which allows for greater coordination and integrates general and school transportation. The proposal is valued economically and compared with the plans of the regional administration. [ABSTRACT FROM AUTHOR]

Objective. Determine the progeny difference expected (DEP) for the weaning weight adjusted to 205 days (PD) in crossbreed Brahman females born in 2016 as selection criteria for future breeders. Materials and methods. It is analyzed 3467 records generated between 1983 and 2016 in the Napo farm (San Vicente, Manabí, Ecuador). The statistical model included the random effect of the father and as fixed effects: breed composition, sex and year of birth. The variance analysis was performed using the GLM procedure of the SAS statistical package. The components of the variance between and within the father to calculate the heritability (h²) of the PD and the breeding values, the MTDFRELM software was used, applying the animal model, through the evaluation system of the Best Linear Unbiased Predictor (BLUP). Results. It was found that the PD average for the 349 females born in 2016 was 173.67±34.23 kg. A highly significant difference (p=0.01) was found for the random and fixed effects. The h² for PD was 0.13±0.04. The DEP fluctuated between -6.13 and +5.58 kg with a range between the breeding values of 11.71 kg and an accuracy between 0.50 and 0.72. Conclusion. The low h² found for PD shows the high influence of non-genetic factors; it is necessary to identify the best crossbreed that adapts to the livestock in order to obtain high performance products in the PD. [ABSTRACT FROM AUTHOR]

The article lists doctoral theses of mathematics that were presented in Spain in year 2018 on several topics including light field distribution within Synechocystis Sp. Pcc 6803 culture, linear systems and random differential equations.

Copyright of Revista Tecno Lógicas is the property of Instituto Tecnologico Metropolitano and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)