Papers by Francisco Manzano
Journal of geodesy, May 27, 2024
This paper introduces a novel method for solving the resection problem in two and three dimension... more This paper introduces a novel method for solving the resection problem in two and three dimensions based on conformal geometric algebra (CGA). Advantage is taken because of the characteristics of CGA, which enables the representation of points, lines, planes, and volumes in a unified mathematical framework and offers a more intuitive and geometric understanding of the problem, in contrast to existing purely algebraic methods. Several numerical examples are presented to demonstrate the efficacy of the proposed method and to compare its validity with established techniques in the field. Numerical simulations indicate that our vector geometric algebra implementation is faster than the best-known algorithms to date, suggesting that the proposed GA-based methods can provide a more efficient and comprehensible solution to the two-and three-dimensional resection problem, paving the way for further applications and advances in geodesy research. Furthermore, the method's emphasis on graphical and geometric representation makes it particularly suitable for educational purposes, allowing the reader to grasp the concepts and principles of resection more effectively. The proposed method has potential applications in a wide range of other fields, including surveying, robotics, computer vision, or navigation.
African archaeological review/The African archaeological review, Apr 20, 2024
Australopiths are a group of early human ancestors that lived approximately 4 to 2 million years ... more Australopiths are a group of early human ancestors that lived approximately 4 to 2 million years ago and are considered a key transitional form between apes and humans. Studying australopiths can help to understand the evolutionary processes that led to the emergence of humans and gain insights into the unique adaptations and characteristics that set humans apart from other primates. A bibliometric-based review of publications on australopiths contained in the Scopus database was conducted, analyzing approximately 2000 of them. The main authors, institutions, and countries researching this subject were identified, as well as their future development. The connections between authors, countries, and research topics were also analyzed through the detection of communities. The more frequent keywords in this subject are hominid, animal, human, South Africa, and Australopithecus afarensis. Four main research clusters were identified in the field of australopiths: palaeobiology, cranial evolution, locomotion, and mandible evolution and morphometry. The most important countries in terms of collaboration networks are South Africa, the UK, France, and Germany. Research on australopiths is ongoing, and new research clusters are expected to emerge, such as those focused on pre-australopiths and the molecular evolution and taxonomy of australopiths. Overall, this work provides a comprehensive overview of the state of research on australopiths and offers insights into the current direction of the field.
Symmetry, Aug 10, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Avanzada Científica, Jun 13, 2011
Resumen El viento puede ser una gran fuente de energía renovable, por ello el conocimiento exhaus... more Resumen El viento puede ser una gran fuente de energía renovable, por ello el conocimiento exhaustivo de su comportamiento es de especial importancia a la hora de abordar cualquier proyecto que contemple su empleo. En el presente trabajo se aplican las técnicas de análisis espectral, mediante la aplicación de la Transformada Rápida de Fourier (FFT), que es una herramienta que permite conocer los diferentes componentes de periodicidad que puedan existir en un fenómeno considerado de tipo periódico y en su caso descubrir si lo es o no. Las variables analizadas fueron la velocidad y dirección del viento, con un periodo de retorno de 2 años, con datos cada 10 minutos, de 23 estaciones meteorológicas del estado de Chihuahua, México. Los resultados obtenidos fueron principalmente dos: 1.157E-005Hz y 2.315E-005Hz, es decir, el estado de Chihuahua cuenta con una periodicidad del viento cada 24 y 12 horas respectivamente, esto es importante para la evaluación del recurso eólico.
Mathematics, Apr 22, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Agrociencia, Nov 9, 2008
RESUMEN Los modelos de infiltración de agua en el suelo que dependen de una medida o dato puntual... more RESUMEN Los modelos de infiltración de agua en el suelo que dependen de una medida o dato puntual, como los de Kostiakov, Philips, Horton, y Green y Ampt, no consideran la influencia de los árboles circundantes. La hipótesis planteada en este trabajo fue que ésta puede influir en los valores genéricos tomados en campo y, por tanto, deben corregirse. Los factores que pueden influir son: la especie arbórea, la distancia al tronco, la altura del árbol y su manejo (cultivado o no). La infiltración fue medida con un infiltrómetro de doble anillo a varias distancias del tronco para tres especies de árboles cultivados con riego: Citrus sinensis, Citrus limon, Olea europaea y otras tres forestales: Eucalyptus globulus, Pinus halepensis, y Tamarix canariensis, así como sobre suelo desnudo y sobre una cubierta continua de césped (Zoysia spp). Realizados los ajustes a los distintos modelos, y tomando la conductividad hidráulica como parámetro para este estudio, se comprobó que es necesario corregir los parámetros de infiltración cuando se usan para superficies arboladas, que la infiltración decrece conforme aumenta la distancia al árbol, y que a mayor altura de éste, mayor es la alteración de la conductividad hidráulica del suelo. Esta metodología permite obtener la densidad óptima de árboles de cada especie, para mantener la infiltración en los mayores valores posibles.
Tecnologia y Ciencias del Agua, 2014
En este trabajo se evaluan los metodos de obtencion de curvas IDF para Mexico: Wencel modificado,... more En este trabajo se evaluan los metodos de obtencion de curvas IDF para Mexico: Wencel modificado, Chen, Chen modificado, Temez y Temez modificado. Los datos proceden de 63 estaciones automaticas (EMAS), distribuidas por todo el pais, con registros cada 10 minutos y durante siete anos como minimo. Para el analisis se han diferenciado estaciones de costa cuando estan a 50 km o menos de esa zona, y las demas como de interior. Se han valorado para cada una de las estaciones, todos los parametros de los metodos de calculo de curvas IDF mencionados, para duraciones entre 10 minutos y 24 horas, y para periodos de retorno de 2 a 500 anos. Se ha comprobado que cuando se tienen registros de lluvia cada 10 minutos o menos, se recomienda el metodo de Wencel; cuando se tienen registros de lluvia horarios, se aconseja el metodo de Chen; cuando los datos de lluvia son diarios, para duraciones menores de 2 h, se necesita el metodo de Temez modificado; para duraciones de mas de 2 h, el mejor es el d...
RESUMEN Los modelos de infiltración de agua en el suelo que dependen de una medida o dato puntual... more RESUMEN Los modelos de infiltración de agua en el suelo que dependen de una medida o dato puntual, como los de Kostiakov, Philips, Horton, y Green y Ampt, no consideran la influencia de los árboles circundantes. La hipótesis planteada en este trabajo fue que ésta puede influir en los valores genéricos tomados en campo y, por tanto, deben corregirse. Los factores que pueden influir son: la especie arbórea, la distancia al tronco, la altura del árbol y su manejo (cultivado o no). La infiltración fue medida con un infiltrómetro de doble anillo a varias distancias del tronco para tres especies de árboles cultivados con riego: Citrus sinensis, Citrus limon, Olea europaea y otras tres forestales: Eucalyptus globulus, Pinus halepensis, y Tamarix canariensis, así como sobre suelo desnudo y sobre una cubierta continua de césped (Zoysia spp). Realizados los ajustes a los distintos modelos, y tomando la conductividad hidráulica como parámetro para este estudio, se comprobó que es necesario corregir los parámetros de infiltración cuando se usan para superficies arboladas, que la infiltración decrece conforme aumenta la distancia al árbol, y que a mayor altura de éste, mayor es la alteración de la conductividad hidráulica del suelo. Esta metodología permite obtener la densidad óptima de árboles de cada especie, para mantener la infiltración en los mayores valores posibles.
Tecnologia y Ciencias del Agua, Jun 1, 2014
This paper assesses the methods of obtaining IDF curves for the country of Mexico: modified Wence... more This paper assesses the methods of obtaining IDF curves for the country of Mexico: modified Wencel, Chen, modified Chen, Témez and modified Témez. The data came from a total of 63 automated weather stations distributed throughout the country, recording data every 10 minutes for a minimum of 7 years. For the analysis, stations 50 km or less from the coast were identified as coastal and the remaining as inland. For each station, all of the parameters for the methods mentioned to calculate the IDF curves were evaluated for durations of 10 minutes to 24 hours, and return periods of 2 to 500 years. It was shown that when rainfall records for 10 minutes or less are used the Wencel method is recommended, and when the records are hourly the Chen method is recommended. When rainfall data are daily for durations under 2 h, the modified Temez method is required, and for durations of more than 2 h the best method is the modified Chen for inland areas and modified Temez for coastal areas.
DOAJ (DOAJ: Directory of Open Access Journals), 2012
RESUMEN: La calidad eléctrica juega un papel importantísimo en las redes eléctricas de hoy en día... more RESUMEN: La calidad eléctrica juega un papel importantísimo en las redes eléctricas de hoy en día. Por esta razón, es de vital importancia contar con herramientas adecuadas que permitan una eficaz detección de anomalías o perturbaciones en dichos sistemas eléctricos. Frente a las técnicas usadas tradicionalmente, como la transforma de Fourier, hoy en día se están desarrollando nuevos métodos basados en transformadas de dominio, como la Transformada Wavelet o la Transformada S, unido a técnicas basadas en inteligencia artificial como la lógica difusa o las redes neuronales. En este artículo se hace un repaso, a la vez que se discuten estas nuevas técnicas, situándolas en contexto con las técnicas tradicionales y poniendo de manifiesto la superioridad y precisión que se consigue aplicando estos nuevos paradigmas matemáticos. Se detalla, fundamentalmente, la Transformada S y la Wavelet como herramienta de gran proyección y futuro en el análisis de la calidad eléctrica debido a su precisión, inmunidad al ruido e información de calidad que aporta.
Energies
The negative consequences of toxic emissions from internal combustion engines, energy security, c... more The negative consequences of toxic emissions from internal combustion engines, energy security, climate change, and energy costs have led to a growing demand for clean power sources in the automotive industry. The development of eco-friendly vehicle technologies, such as electric and hydrogen vehicles, has increased. This article investigates whether hydrogen vehicles will replace electric vehicles in the future. The results showed that fuel-cell cars are unlikely to compete with electric cars. This is due to the advancements in electric vehicles and charging infrastructure, which are becoming more cost-effective and efficient. Additionally, the technical progress in battery electric vehicles (BEVs) is expected to reduce the market share of fuel-cell electric vehicles (FCEVs) in passenger vehicles. However, significant investments have been made in hydrogen cars. Many ongoing investments seem to follow the sunk cost fallacy, where decision-makers continue to invest in an unprofitabl...
Electric Power Systems Research, 2020
The aim of this work is to present major upgrades to existing power theories based on geometric a... more The aim of this work is to present major upgrades to existing power theories based on geometric algebra for single-phase circuits in the frequency domain. It also embodies an interesting new approach with respect to traditionally accepted power theories, revisiting power concepts in both sinusoidal and non-sinusoidal systems with linear and nonlinear loads for a proper identification of its components to achieve passive compensation of true non-active current. Moreover, it outlines traditional power theories based on the apparent power S and confirms that these should definitively be reconsidered. It is evidenced that traditional proposals based on the concepts of Budeanu, Fryze and others fail to identify the interactions between voltage and current harmonics. Based on the initial work of Castro-Núñez and others, new aspects not previously included are detailed, modified and reformulated. As a result, it is now possible to analyze non sinusoidal electrical circuits, establishing power balances that comply with the principle of energy conservation, and achieving optimal compensation scenarios with both passive and active elements in linear and non-linear loads.
Renewable Energy, 2018
The demand on energy has reached very high levels, the main reason of it, is the rapid 23 increas... more The demand on energy has reached very high levels, the main reason of it, is the rapid 23 increase of urbanization, the neighbourhoods, built environment, public transportation and 24 services. In order to achieve energy sustainability, renewable energies must be taken into 25 account. Among the renewable energies, wind energy is one of the most sustainable, 26 research in this field is a crucial role for the development of a country as Mexico. This 27 paper analyzed the contribution of Mexican institutions in literature specialized on wind 28 during the period 1969-2016, considering complete years; 31,890 documents have been 29 considered. It has been used Elsevier's Scopus database and bibliographic analysis 30 techniques, considering in the analysis all the material reported by Scopus as source type,
Renewable and Sustainable Energy Reviews, 2016
Palestine is a developing country of a different nature from that of the developing countries of ... more Palestine is a developing country of a different nature from that of the developing countries of the world. It is a state under occupation that does not have many natural resources. It is prohibited from exploiting its natural resources such as water, salt, and natural gas, and even producing or importing electricity, occupation is the total importer of fossil fuels, adding 87% of its electricity needs. The design of green energy-saving buildings, combined with the exploitation of renewable energy resources, especially solar energy, with 3000 sunshine a year and an average of solar radiation of 5.4 kW h/m 2 /day, may be the only way out of the current situation. The main objective of this work is to provide a review of the green building sector in Palestine in terms of research issued, governmental and non-governmental bodies concerned with the development of this field, in addition to the most important projects implemented as green building in Palestine, and finally discussing the most important obstacles hindering the adoption of green building as a long-term sustainable development strategy. Our urban heritage has an architectural and construction style that meets the requirements of sustainable construction. However, the rapid and dramatic change in the construction sector, in terms of building materials and construction, has increased the energy burden. Throughout Palestine there are seven climatic zones, which in itself is a challenge to the design of green construction, in addition to low public awareness of the concept of sustainable construction. The study concluded that, the absence of legislations and laws binding the minimum requirements of green building are among the most important obstacles to the adoption of sustainable construction as a long-term strategy to achieve the desired independence in the energy sector, in addition to the non-use of financial tools to stimulate investment in the green building sector in Palestine.
Dyna (Medellin, Colombia)
Journal of Maps, 2013
The Geographic Atlas of Spain (AGE) designed by Tomas Lopez in1804 consisted of an anthology of m... more The Geographic Atlas of Spain (AGE) designed by Tomas Lopez in1804 consisted of an anthology of maps of the Spanish regions that was drawn in the second half of the eighteenth century. It was the most ambitious and successfully completed cartographic work undertaken to date. Nowadays there is no study that examines this work as a whole. This paper analyzes the complete cartographic errors of this work in Spain. A total amount of 90 sheets of maps, from 36 kingdoms or provinces of Spain in 1804 have been analyzed. A total of 21,800 settlements or towns have been digitized, which have been linked to the current ones about 75%. Linear error of each settlement has been calculated by comparing the historical mapping coordinates to the current ones. The average linear error obtained for all analyzed settlements was 6.5 km. Linear errors of all settlements have been represented for Spain by GIS. Finally, an inverse relationship between the higher density of settlements and the largest linear error has been found; as well as the communication networks of that time act as corridors that connect areas of lower errors.
Journal of Cleaner Production, 2013
ABSTRACT Monitoring environmental parameters in the Amazon Rainforest is currently of great signi... more ABSTRACT Monitoring environmental parameters in the Amazon Rainforest is currently of great significance, as the rainforest actively contributes to the reduction of the climate change impact. The present study demonstrates the integration of various communication technologies based on open source software for monitoring environmental parameters in the Peruvian Amazon. The Napo River is a direct tributary of the Amazon River, connecting 450 km in the region of Loreto, Peru. The WiFi network that runs alongside the river is considered the longest in the world. This network will serve as a transport network over which available measurements, including humidity, temperature, total solar radiation (TSR), photosynthetically active radiation (PAR), and volumetric water content from the environmental sensors, will be relayed. The linkage between the diverse technologies, from the sensor network to the communication network, and the visualisation on the Internet are explained. The entire project has been planned using low-cost sensors, open source software, and minimal energy consumption.
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Papers by Francisco Manzano
as electrostatic precipitators (ESPs) or fabric filters. Currently, these ESPs take 25 or 35 years in service and if the performance expectations
of their Plants are positives, improving investments required which can adapt to the new particulate emission limits becoming more
stringent. This paper analyzes an alternative means great savings in investment costs; Conversion of the existing ESP casing to a Pulse Jet
fabric filter. This study also presents a real case, implementing this conversion with good results in unit of 660 MW power plants of Italy.