Tópicos Sugeridos dentro de su búsqueda.
Tópicos Sugeridos dentro de su búsqueda.
Buscar alternativas:
para variable » para variables (Expander búsqueda), una variable (Expander búsqueda), la variable (Expander búsqueda)
para variable » para variables (Expander búsqueda), una variable (Expander búsqueda), la variable (Expander búsqueda)
1
artículo
Publicado 2019
Enlace
Enlace
Background: Mechanical reasoning (MR) is the ability to identify the components of a system and understand how they interact in order for the system to work. Different mechanical systems, such as those of wheels and gears, require different types of reasoning. Objective: This study seeks to analyze the relationship that working memory (WM) and processing speed (PS) have with MR. Method: One hundred seventy-three (173) university students were assessed through the DAT test which consisted of 30 MR problems, the symbol search subtest of the WAIS-III battery for assessing the PS, and the BIMET-V and BIMET-VE batteries to evaluate the WM verbal and visuospatial components. Results: Regression analyses showed that the proposed variables do not predict the performance in gear problems, while the visuospatial WM and the PS predict the performance in wheel problems. Discussion: The results sugge...
2
artículo
The stirring speed required for the culture of kefir grains was studied, to optimize its growth in a culture medium of molasses and whey. The results show that this mixture of microorganisms requires stirring to optimize its growth and can grow in a wide range of stirring speeds, from laminar flow, with Reynolds number lower than 2000, to turbulent flow with Reynolds number greater than 3500. This shows that the culture of kéfir grains, can adapt to different stirring speeds, making its culture very easy with respect to this variable
3
artículo
The stirring speed required for the culture of kefir grains was studied, to optimize its growth in a culture medium of molasses and whey. The results show that this mixture of microorganisms requires stirring to optimize its growth and can grow in a wide range of stirring speeds, from laminar flow, with Reynolds number lower than 2000, to turbulent flow with Reynolds number greater than 3500. This shows that the culture of kéfir grains, can adapt to different stirring speeds, making its culture very easy with respect to this variable
4
tesis de maestría
Publicado 2017
Enlace
Enlace
La aplicación del modelo de los cuantos vectoriales en la propagación de la luz y el logro del aprendizaje de la velocidad variable de la luz en estudiantes de la Facultad de Ciencias Físicas de la Universidad Nacional Mayor de San Marcos, es un trabajo de investigación que propone la enseñanza de nuevos conocimientos generados de la investigación científica incluyéndolos en una o más unidades didácticas de asignaturas afines con la Física contemporánea. El estudio muestra que al aplicar el modelo de los cuantos vectoriales en la propagación de la luz en el vacío se obtiene una ecuación que describe la variación de la velocidad de la luz con el tiempo para una magnitud dada del cuanto vectorial asociado a la escala espacial en consideración. Mediante el uso de instrumentos de evaluación adecuados se demuestra el logro del aprendizaje de nuevos conocimientos generados de...
5
artículo
Cotton is an important industrial crop in the textile sector, it is the most important natural fiber produced in the world. The quality of cotton fiber is mainly reflected in length, fineness and resistance. The cotton fiber arrives attached to the seeds from the field and goes through the ginning process. The objective of the present study was to find a relationship between the RPM speeds at which the saw gin works used for cotton ginning, and the fiber length, fineness and resistance. Data were obtained from the average of ten samples, ten samples of between 18 and 20 grams of cotton fiber were used as an experimental unit. The response variables were the length of 2.5% of the fiber, 50, 60 and 70%, as well as the fineness and strength of the fiber. The experimental design was a CRD with nine repetitions and three treatments that were 700, 650 and 580 RPM. A significant difference betw...
6
artículo
Cotton is an important industrial crop in the textile sector, it is the most important natural fiber produced in the world. The quality of cotton fiber is mainly reflected in length, fineness and resistance. The cotton fiber arrives attached to the seeds from the field and goes through the ginning process. The objective of the present study was to find a relationship between the RPM speeds at which the saw gin works used for cotton ginning, and the fiber length, fineness and resistance. Data were obtained from the average of ten samples, ten samples of between 18 and 20 grams of cotton fiber were used as an experimental unit. The response variables were the length of 2.5% of the fiber, 50, 60 and 70%, as well as the fineness and strength of the fiber. The experimental design was a CRD with nine repetitions and three treatments that were 700, 650 and 580 RPM. A significant difference betw...
7
artículo
Cotton is an important industrial crop in the textile sector, it is the most important natural fiber produced in the world. The quality of cotton fiber is mainly reflected in length, fineness and resistance. The cotton fiber arrives attached to the seeds from the field and goes through the ginning process. The objective of the present study was to find a relationship between the RPM speeds at which the saw gin works used for cotton ginning, and the fiber length, fineness and resistance. Data were obtained from the average of ten samples, ten samples of between 18 and 20 grams of cotton fiber were used as an experimental unit. The response variables were the length of 2.5% of the fiber, 50, 60 and 70%, as well as the fineness and strength of the fiber. The experimental design was a CRD with nine repetitions and three treatments that were 700, 650 and 580 RPM. A significant difference betw...
8
artículo
The propagation of light in 99,99 % of empty space existing in natural systems is investigated to a new level of description, assuming that light is the only inuence that can transmit information. First, the electromagnetic eld is considered as a non-inertial reference system and it is deduced by geometric reasoning that the propagation vector of the electromagnetic wave changes direction at each instant of time due to the angular velocity associated with the plane of vibration of the electric/magnetic eld. Consequently, the actual path of a ray of light would have the shape of a conical spiral. The geometric analysis of the path of light rays in a vacuum lead to a simple formulation of the parametric equations that would represent the essential kinematics of the points of the empty space of natural systems (the substrate). This leads to an equation that describes the variation of the sp...
9
artículo
Field orientation control is a technique used in AC servo mechanisms that makes it possible to achieve a rapid torque response because it is based on the interaction between flux and current as in a DC motor. An alternative for servo controlmechanisms in AC is the Direct Torque Control that represents an advance in the objective of improving the performance and reliability in the control of induction motors and is fundamentally based on the comparison of the instantaneous values of Torque and Flow, calculated from of its primary variables (stator voltage and current), with their respective reference values. The resulting Flow and Torque errors are processed by hysteresis controllers to then select the voltage to be applied, through the activation of the power switches of a three-phase voltage inverter. The selection criteria are made so that there is a rapid torque response and hig...
10
artículo
Publicado 2007
Enlace
Enlace
In the present work I analyzed the variability of the seeds size of Vismia glaziovii Ruhl. and its Vismia glaziovii Ruhl. and its Vismia glaziovii possible effect on germination speed and its seedling size. The results show that the size of the seeds does not vary signifi cantly between trees from which they came; but the variation as large as seed between the fruits of each tree is signifi cant. Also, the size of the seed does not infl uence the speed of germination nor the seedling size. We suggested that variability in size is not suffi cient as indicator of differences in the amount of stored resource. This study will allow contributing to the knowledge of some aspects of the dynamics of seeds and the regeneration of this species.
11
artículo
Publicado 2022
Enlace
Enlace
Autism Spectrum Disorder (ASD) is considered a neurodevelopmental disorder, whose prevalence has increased in recent years, showing in some cases deficits in the cognitive area, with processing speed (PS) being one of the affected variables. Therefore, the present study aims to: 1) compare the scores obtained in relation to the PS variable between students aged 6 to 11 with ASD and their peers with neurotypical development in Metropolitan Lima; and 2) establish the PS profile of the included students with ASD. For this, 30 children aged 6 to 11 attending to regular basic education institutions (RBE) in Metropolitan Lima were sampled, 15 with neurotypical development and 15 included with ASD. For the first objective, a case-control design (CCD) was used, while the second objective was a selective non-probabilistic cross-sectional design. Results showed a lower performance by the group wit...
12
tesis de grado
Publicado 2020
Enlace
Enlace
El presente trabajo de investigación tuvo el objetivo de determinar en qué medida las políticas de crédito se relacionan con el activo disponible, en la empresa Lava Speed SAC, Ate 2020. El desarrollo de esta investigación fue siguiendo la metodología de tipo correlacional, con un diseño no experimental y de corte trasversal. La recolección de datos se hizo a través de encuestas para cada variable, la misma fue aplicada a 17 personas. Los resultados fueron: 1) la relación entre las políticas de crédito y el activo disponible fue de 56.4%; 2) la relación entre los procesos de cobranza y el activo disponible fue de 58.9 %; 3) la relación entre la evaluación de crédito y el activo disponible fue de 27.1%. Se concluyó en que 1) las políticas de crédito se relacionan en forma positiva, media y significativa con el activo disponible; 2) la evaluación de crédito se relacion...
13
artículo
Publicado 2012
Enlace
Enlace
This paper describes the influence of process variables to produce orange vinegar. Orange juice was fermented with Saccharomyces cerevisiae until reach 14% v/v. The biooxidation was carried out with Acetobacter sp., in submerge culture using a laboratory scale fermentor. In order to avoid the inhibitory effect of ethanol on acetic acid bacteria, the orange wine was diluted to 6% v/v with a mineral solution. It was performed a factorial design 2k to study the influence of variables. It was studied air flow rate/agitation at levels of 0.3-0.6 vvm and 200-400 rpm and the effect of air flow rate/temperature at 0.4-0.6 vvm and 25-30°C, respectively. Duplicate treatments were carried out and the results were evaluated in terms of productivity and fermentation yield. Statistical design (p-value<0.05) was analyzed using Statgraphics Centurion XV Corporate software. Treatments performed at 20...
14
artículo
Publicado 2012
Enlace
Enlace
This paper describes the influence of process variables to produce orange vinegar. Orange juice was fermented with Saccharomyces cerevisiae until reach 14% v/v. The biooxidation was carried out with Acetobacter sp., in submerge culture using a laboratory scale fermentor. In order to avoid the inhibitory effect of ethanol on acetic acid bacteria, the orange wine was diluted to 6% v/v with a mineral solution. It was performed a factorial design 2k to study the influence of variables. It was studied air flow rate/agitation at levels of 0.3-0.6 vvm and 200-400 rpm and the effect of air flow rate/temperature at 0.4-0.6 vvm and 25-30°C, respectively. Duplicate treatments were carried out and the results were evaluated in terms of productivity and fermentation yield. Statistical design (p-value<0.05) was analyzed using Statgraphics Centurion XV Corporate software. Treatments performed at 20...
15
artículo
Publicado 2019
Enlace
Enlace
Objective: To determine the association between presence of neurological comorbidities and walking speed in older adults attended at the Naval Medical Center Cirujano Mayor Santiago Távara 2010-2015. Methods: Observational retrospective study through secondary analysis of a database of 1785 older adults. To determine the relationship between variables, the Chi-square test with a level of significance of 5%, and the STATA v.14 program were used. Results: 18.7% of the probands had Parkinsons disease, 44.9% had mild cognitive impairment, and only 3.1% had cerebrovascular disorder. There were significant differences in walking speed with respect to advanced age and female sex (greater in 80 y.o. or older females). There was a significant relationship between mild cognitive impairment and cerebrovascular disorder with walking speed. The probability of a slow walking speed adj...
16
artículo
Publicado 2025
Enlace
Enlace
El desempeño de diferentes estrategias para resolver colisiones en tablas hash sondeo lineal, sondeo cuadrático y listas enlazadas fue evaluado, junto con tres funciones hash no criptográficas de alto rendimiento: Fowler-Noll-Vo versión 1a de 32 y 64 bits, y xxHash de 64 bits, bajo criterios de eficiencia temporal y consumo de memoria. La metodología adoptó un enfoque aplicado y experimental que consideró múltiples configuraciones, variando tamaños de tabla y cargas de trabajo, para simular escenarios reales y complejos. Tras superar las fases iniciales de redimensionamiento, que causan picos temporales disruptivos, tanto el direccionamiento abierto como las listas enlazadas lograron niveles estables y comparables de rendimiento en inserción y búsqueda. Se resalta que las listas enlazadas, debido a la gestión de referencias adicionales, presentan un consumo de memoria ligeram...
17
tesis de grado
Publicado 2025
Enlace
Enlace
El presente estudio analiza el efecto del acceso a conexiones de banda ancha fija, clasificadas por rangos de velocidad, sobre el ingreso promedio mensual proveniente del trabajo a nivel departamental en el Perú durante el período 2015-2023. Reconociendo el riesgo de endogeneidad en estudios previos como los de Koutroumpis (2009) y Katz y Callorda (2019), se plantea emplear modelos econométricos de variables instrumentales para identificar relaciones causales más precisas.La variable dependiente que el presente estudio propone utilizar es el logaritmo del ingreso promedio mensual proveniente del trabajo, como un proxy del desempeño económico departamental. Las principales variables explicativas son los niveles de velocidad de conexión por cada mil habitantes de la población económicamente activa (PEA), complementadas por variables de control: porcentaje de hogares con electricid...
18
tesis de grado
Publicado 2022
Enlace
Enlace
In Peru, constructions are commonly built with cement and bricks, then proceed to decorate and embellish the walls using texturing. Currently, in Peru, this process is done in a traditional way where generally support tools are used such as trowels, rollers, and brushes, among others. As this process is done manually, the texturing is of lower aesthetic quality. Due to its geographic location, Peru is one of the countries that most often applies cement in its constructions, which makes it the most accessible and suitable material for applying textures to walls. Currently, there is no specific machine for texturing, so the conceptual design of a lightweight machine for texturing on concrete surfaces was proposed using the VDI 2221 design methodology, integrating a variable speed control system and display of parameters in real-time.
19
tesis de grado
Publicado 2019
Enlace
Enlace
En la presente tesis se ha desarrollado un sistema de medición modular autónomo (SMA) capaz de realizar mediciones con diversos sensores análogos y digitales con diferentes protocolos de comunicación, como serial, I2C, SPI, GPIO, etc. El SMA posee su propio sub-sistema de alimentación autónomo solar fotovoltaico, además que su diseño se adapta a condiciones rurales, donde el SMA puede ser expuesto a las lluvias, el polvo, la radiación solar, así como otros. Este proyecto surge como alternativa simple para ser el elemento central en mediciones multiparamétricas, el cual permite recolectar información cada cierto tiempo en una memoria microSD interna y además tiene la potencialidad de transmisión de información inalámbrico a través de conexión vía Wi-Fi o Bluetooth y de georreferenciación usando un módulo GPS. Para probar el SMA se le conectaron sensores de temperatura...
20
artículo
Publicado 2024
Enlace
Enlace
Objective: To evaluate the relationship between anthropometric profile and serve speed in male Peruvian tennis players. Methods: A quantitative, observational, cross-sectional, and analytical study was conducted with 79 male tennis players from the FiXU sports medical center in Lima, Peru, during 2023 and 2024. Variables such as height, weight, BMI, and limb dimensions were measured. Serve speed was assessed using a calibrated speed gun. Results: The average serve speed was 94.38 km/h (±9.98). The average height of the players was 174.61 cm (±4.17) and the average weight was 72.20 kg (±6.97). Height (r=0.796) and weight (r=0.533) showed significant correlations with serve speed. Weekly playing hours (r=0.611) and years of experience (r=0.435) also showed positive associations. Linear regression identified height (B=1.91, p<0.001), weight (B=0.76, p<0.001), and forearm length (B=...
