Fungal infection in plant leaves-A Review

The primary resource of a country is agriculture and crop production. The economic development of the country also resides on the agricultural products which ultimately determines the growth of the citizen. The major crisis in food production is the influence of diseases in plants. This ultimately abolish the economy of the country, as major portion of progress of the nation is dependent on agriculture and its products. The challenges faced by the farmers are the unawareness of the various diseases that affects different parts of the plants. They should be able to identify the early infection caused in plants by different pathogens like bacteria, fungi, virus etc., Main disease-causing agent is found to be the fungus which was the vital factor that produce serious loss in the agriculture. Again, the pesticides and fertilizers used by the agriculturist changes to be hazardous for human beings and wild life species. This problem should be considered as a chief calamity and an alternate measure must be found to support the cultivators. An innovative step adopted by the researchers are prompt detection of the diseases using machine learning and deep learning algorithms. These algorithms use different image processing techniques and computer vision process to classify the disease in plant parts at an earlier stage. This paper provides a detailed review on the fungal infection caused in plant leaves and its identification using deep learning methodology

An Automatic Rice Plant Disease Detection Model Built With Unstructured Data Using IMDT Tiling and CNN Cognitive Object Detection

Nowadays agriculture and processes are getting more intelligent mechanisms to improve the yield and reduce manual work. Smart agriculture provides numerous modern ideologies to farmers. But still, farmers face one important issue crop disease. Many researchers provide plenty of ways to recover and tackle the situation to come out of this problem. Therefore, they proceed with image processing to identify diseases from rice plant images. Farmers mainly face problems to take proper images for classification. Because of various reasons like various environmental factors, farmers ignorance, field size, capturing angle, device limitations, etc. are affecting the quality of the disease detection system, and these factors degrade overall performance. For this problem, introducing the Intelligent multi-dimensional tiling (IMDT) technique with an advanced convolution neural network with cognitive object detection (CNN-COD). IMDT technique developed with an intelligent expert system that adjusts input image size, capturing angles and other factors automatically. This advanced tiling technique supports to do the cropping and fluttering of input images for resizing. And CNN-COD model was used to calculate rice leaf width size and rescaled at the time of image segmentation with the Residual network (ResNet) model. Created dynamic tiled images are uniformly and scaled dimensional objects. These input values are used to train the CNN-COD rice plant disease, prediction model. Our proposed models were appraised on more than 4960 images which contain 8 various types of rice crop diseases. The experimental result portrayed out the CNN-COD model receives significant improvement in objection detection and image classification for the rice plant disease detection system. Mean average precision (MAP) values compared the CNN-COD model with the YOLOv4 model it got improved by 3.7% with the tiled input dataset

Apple Leaf Disease Classification Using Image Dataset: a Multilayer Convolutional Neural Network Approach

Agriculture is one of the prime sources of economic growth in Russia; the global apple production in 2019 was 87 million tons. Apple leaf diseases are the main reason for annual decreases in apple production, which creates huge economic losses. Automated methods for detecting apple leaf diseases are beneficial in reducing the laborious work of monitoring apple gardens and early detection of disease symptoms. This article proposes a multilayer convolutional neural network (MCNN), which is able to classify apple leaves into one of the following categories: apple scab, black rot, and apple cedar rust diseases using a newly created dataset. In this method, we used affine transformation and perspective transformation techniques to increase the size of the dataset. After that, OpenCV crop and histogram equalization method-based preprocessing operations were used to improve the proposed image dataset. The experimental results show that the system achieves 98.40% training accuracy and 98.47% validation accuracy on the proposed image dataset with a smaller number of training parameters. The results envisage a higher classification accuracy of the proposed MCNN model when compared with the other well-known state-of-the-art approaches. This proposed model can be used to detect and classify other types of apple diseases from different image datasets

Crisis económica y crisis política

Un ambiente político favorable es una condición necesaria para un buen manejo económico que inevitablemente afecta intereses. Los grupos están más dispuestos a aceptar los costos cuando los gobiernos tienen una imagen favorable y cuentan con un amplio apoyo ciudadano.A favorable political environment is a necessary condition for good economic management that inevitably affects interests. Groups are more willing to accept the costs when governments have a favorable image and broad citizen support

Navigation of an autonomous mobile robot using the combined force field concept

En este artículo se presentan el desarrollo, prueba y resultados obtenidos de un algoritmo de evasión de obstáculos basado en el método de campo de potencial (PFM, por su sigla en inglés) y combinado con el método de seguimiento de contornos, para resolver el problema del mínimo local que posee el PFM. Adicionalmente, se divulgan los resultados de la investigación, cuyo propósito fue desarrollar un algoritmo que permitiera a un robot móvil desplazarse en forma autónoma, con el fin de alcanzar una meta, evitando los obstáculos que encontrara en su trayectoria. Los requerimientos para el diseño del algoritmo fueron alta velocidad de respuesta, bajo consumo de recursos de hardware y capacidad de respuesta ante situaciones no previstas. Las simulaciones demuestran que el algoritmo soluciona el problema del mínimo local, inherente al uso del PFM, y puede implementarse en un robot real, cumpliendo con las características citadas previamente.This article presents the development, testing and results from an obstacle avoidance algorithm based on potential field method (PFM), combined with the contour following method to solve the problem of local minimum in the PFM. In this paper, we report the findings of the research, whose objective was to develop an algorithm that allowed a mobile robot to navigate autonomously to reach a goal, avoiding obstacles in its path. Requirements for the design of the algorithm were high response speed, low consumption of hardware resources and capacity answer to unforeseen situations. The simulations show that the algorithm solves the problem of local minimum-inherent in the use of PFM-and it can be implemented in a real robot, since it fulfills the mentioned characteristics

Caracterización de agregados pétreos con el ensayo Micro Deval

En este documento se presentan los aspectos más relevantes del proceso de implementación del ensayo Micro Deval, contemplado por la Norma ASTM D 6928, “Standard test method for resistance of coarse aggregate to degradation by abrasion in the Micro-Deval apparatus”, en los laboratorios de Suelos y Pavimentos del Centro de Estudios Geotécnicos de la Escuela Colombiana de Ingeniería. En esta segunda parte se incluyen los resultados obtenidos de los ensayos Micro Deval y de Desgaste Los Ángeles y sus variantes (100 rev. y en húmedo 500 rev.) realizados sobre 15 muestras de agregados, utilizados en la ciudad de Bogotá principalmente para la elaboración de mezclas asfálticas. Igualmente, se incluye el análisis de estos resultados junto con unas conclusiones preliminares, así como algunas recomendaciones derivadas de este proceso. Como se ha mostrado en otros estudios, sobre los materiales analizados en el presente no se evidenció una adecuada correlación con el ensayo de Desgaste Los Ángeles, ni con la absorción de los agregados. Sin embargo, las líneas de tendencia muestran un incremento en las pérdidas medidas con el ensayo de Desgaste Los Ángeles y en la absorción con el aumento en las pérdidas en el Micro Deval. Del análisis de los resultados encontrados también se concluye que si se tienen en cuenta los requisitos del agregado grueso para mezclas asfálticas en caliente, fijados por el IDU en las Especificaciones ET-2005, para tránsitos pesados (tipo T4 –T5) y capas de rodadura, el ensayo de Desgate Los Ángeles resulta ser más conservador que el Ensayo Micro Deval. Se recomienda continuar evaluando fuentes de materiales para seguir ajustando las respectivas especificaciones a las condiciones imperantes en nuestro medio.This report shows the most relevant aspects of the implementation of the Micro Deval test, according to ASTM D 6928, “Standard test method for resistance of coarse aggregate to degradation by abrasion in the Micro-Deval apparatus”, at the Escuela Colombiana de Ingeniería Soils and Pavements Laboratory. Micro-Deval and Los Angeles tests results in 15 samples of aggregates used in Bogotá, principally for asphalt mixes, are shown as well as the analyses of these results along with preliminary conclusions and recommendations. As other studies have shown, the Micro-Deval results had no correlation with the Los Angeles and aggregates absorption results. The trend lines do, however, show increasing Los Angeles Abrasion and absorption results with the increasing Micro Deval results. From the analysis of the materials results used in this investigation, it can be concluded that the Los Angeles test is more conservative than Micro-Deval test, for coarse aggregate used in hot asphalt mixes under IDU high volume of traffic (types T4 – T5) and surface courses, according the Specifications IDU ET-2005. It is recommended to evaluate more aggregate sources to continue adjusting specifications to our particular conditions

Setting asphalt temperature viscosity for designing hot-mix asphalt

El estándar actual para la determinación de la viscosidad con el viscosímetro rotacional (INV E-717) exige que para cada temperatura a la que se quiera determinar la viscosidad del asfalto se utilicen diferentes muestras de ensayo. Considerando que para la construcción de las curvas de susceptibilidad térmica del asfalto (VTS) es necesario determinar la viscosidad a diferentes temperaturas, se deben ensayar varias muestras. Para evitar la utilización de muestras diferentes para cada temperatura, se realizó un estudio con el fin de desarrollar una metodología alternativa que permita establecer curvas VTS del asfalto a partir de ensayos de viscosidad efectuados en una sola muestra. Los resultados indican que las temperaturas de mezcla y compactación estimadas con las curvas VTS, establecidas a partir de la metodología propuesta, son prácticamente iguales a las determinadas siguiendo la normativa vigente, y podrían utilizarse para determinar las características de susceptibilidad térmica de los asfaltos para el diseño de mezclas asfálticas en caliente.The current test standard for rotational viscosity determination (INV E-717) demands that different test specimens be used to determine viscosity at each temperature of interest. Since the development of the Viscosity-Temperature Susceptibility (VTS) curve of given asphalt binder requires the evaluation of its viscosity at different temperatures, different samples are necessary to gather the required information. To avoid inconveniences and time losses involved in using different samples for each temperature level, we conducted a study aimed at developing an alternative methodology to determine VTS curves of asphalt binders using only one test specimen. The results indicate that mixing and compaction temperatures estimated with the VTS curves developed with the proposed methodology yield the same values than those obtained following the current standard. We could use it as an alternative methodology to determine the viscosity-temperature susceptibility characteristics of asphalt binders used for designing hot mix asphalt

Carbonation in bridges and buildings in Bogota

Se presentan y analizan los resultados de dos proyectos de grado de la Especialización en Estructuras de la Escuela Colombiana de Ingeniería, en los que se recopiló la información sobre carbonatación en edificios y puentes de Bogotá, obtenida en estudios de patología realizados entre 1999 y 2004. Se encontró que en aproximadamente el 50% de los elementos estudiados, el frente de carbonatación ya ha alcanzado o está muy próximo a alcanzar el refuerzo y que un 40% ya ha empezado a sufrir corrosión. También se halló que el avance del frente de carbonatación y el desarrollo de corrosión en el acero de refuerzo son relativamente altos en estructuras jóvenes, en comparación con estructuras de mayor edadIn this paper, results from several forensic investigations regarding carbonation made from 1999 to 2004 on Bogotá bridges and buildings, and compiled by two groups of graduate students at the Escuela Colombiana de Ingeniería are presented and analyzed. The carbonation front already reached or is close to reach the steel reinforcement in about 50% of the elements that were explored, and that active corrosion is occurring in about 40% of the elements. Finally, the degree of carbonation and corrosion of steel is relatively high in young structures when compared to old ones

El ensayo Micro Deval. Sus características y ámbitos de aplicación

En este documento se presentan los aspectos más relevantes del proceso de implementación del ensayo Micro Deval, contemplado por la Norma ASTM D 6928, “Standard test method for resistance of coarse aggregate to degradation by abrasion in the Micro-Deval apparatus”, en los laboratorios de Suelos y Pavimentos del Centro de Estudios Geotécnicos de la Escuela Colombiana de Ingeniería. En el proceso de implementación se evaluaron las principales características, ventajas y limitaciones del ensayo, los factores que afectan sus resultados, las correlaciones con otros ensayos relacionados con la dureza y con la durabilidad de los agregados, en especial con el ensayo de Desgaste Los Ángeles, y las correlaciones del ensayo con el comportamiento en servicio de los pavimentos, obtenidas en diferentes ambientes por diversos autores. Estos aspectos se tratan en este documento y se dejan para otro documento los resultados encontrados, al aplicar el ensayo Micro Deval, sobre agregados provenientes principalmente de fuentes de la ciudad de Bogotá. Se concluye en general que el Ensayo Micro Deval tiene gran aceptación, es simple, consume poco tiempo, tiene buena repetibilidad, reproducibilidad y comprobada correlación con el comportamiento en servicio de los agregados, ya se usen para la conformación de capas granulares o para la elaboración de mezclas asfálticas.This report shows the most relevant aspects of the implementation of the Micro Deval test, according to ASTM D 6928, “Standard test method for resistance of coarse aggregate to degradation by abrasion in the Micro-Deval apparatus”, at the Escuela Colombiana de Ingeniería Soils and Pavements Laboratory. During the implementation process the main characteristics, advantages, weaknesses, limiting factors of the test were evaluated, as well as correlations with other tests related to hardness and durability of aggregates, particularly the Los Angeles test and correlations with pavements in-service performance in different environments according to different authors. It is concluded that the Micro-Deval test is a widely accepted test, simple, no time consuming, has good repeatability, reproducibility and shows good correlation with aggregates in-service performance, either for granular bases or asphalt mixes. As other studies have shown, the Micro-Deval results had no correlation with the Los Angeles and aggregates absorption results

El crecimiento a largo plazo: Resumen ejecutivo

Los trabajos de Solow, en 1956 y 1957, constituyen los aportes más significativos sobre el proceso de crecimiento y sus causas. Sin duda, representaron un paso trascendental para demostrar que, luego de la revolución industrial, el estado normal es el aumento persistente del ingreso per cápita. Sin embargo, en los últimos cincuenta años no se ha avanzado mayormente en establecer la contribución directa del capital y la tecnología en los diferentes tipos de economías, y el grado de interrelación entre ellos. Ni el trabajo de Solow ni el de los autores de la nueva teoría del crecimiento, entre los cuales sobresalen Romer y Lucas, suministran una explicación adecuada de las fuentes de crecimiento de las economías en desarrollo. Todos ellos coinciden en señalar que el avance tecnológico es la única causa del crecimiento del ingreso per cápita a mediano y largo plazo.The works of Solow, in 1956 and 1957, constitute the most significant contributions on the growth process and its causes. Undoubtedly, they represented a transcendental step in demonstrating that, after the industrial revolution, the normal state is a persistent increase in per capita income. However, in the last fifty years no major progress has been made in establishing the direct contribution of capital and technology in the different types of economies, and the degree of interrelation between them. Neither Solow's work nor that of the authors of the new growth theory, including Romer and Lucas, provide an adequate explanation of the sources of growth in developing economies. All of them coincide in pointing out that technological progress is the only cause of growth in per capita income in the medium and long term