A computer vision approach for weeds identification through Support Vector Machines

This paper outlines an automatic computervision system for the identification of avena sterilis which is a special weed seed growing in cereal crops. The final goal is to reduce the quantity of herbicide to be sprayed as an important and necessary step for precision agriculture. So, only areas where the presence of weeds is important should be sprayed. The main problems for the identification of this kind of weed are its similar spectral signature with respect the crops and also its irregular distribution in the field. It has been designed a new strategy involving two processes: image segmentation and decision making. The image segmentation combines basic suitable image processing techniques in order to extract cells from the image as the low level units. Each cell is described by two area-based attributes measuring the relations among the crops and weeds. The decision making is based on the SupportVectorMachines and determines if a cell must be sprayed. The main findings of this paper are reflected in the combination of the segmentation and the SupportVectorMachines decision processes. Another important contribution of this approach is the minimum requirements of the system in terms of memory and computation power if compared with other previous works. The performance of the method is illustrated by comparative analysis against some existing strategies

A Mercantilist Approach to the Chinese Economic Growth: Balance of Trade, GDP, and Investment

Este documento estudia las relaciones de corto y largo plazo entre el comercio, la inversión y el crecimiento económico chino desde 1992 hasta 2019. Se estimó un modelo de corrección de errores vectoriales (CEV) para analizar las relaciones causales entre la balanza comercial, la inversión (tanto nacional como extranjera), y el crecimiento económico. Los resultados nos ayudaron a discutir los mecanismos considerados dentro de la literatura mercantilista para relacionar una balanza comercial positiva y el crecimiento económico. La estimación sugiere un mecanismo causal entre las variables más cercana a la explicación del mercantilismo financiero o del desarrollismo frente al acercamiento del mercantilismo monetario. Esto es, el efecto positivo de la balanza comercial sobre el crecimiento económico de China parece estar relacionado con el aumento de la inversión nacional en vez de la atracción de inversión extranjera directa.This paper studies the short-run and long-run relationships between trade, investment, and the Chinese economic growth from 1992 to 2019. A vector error correction (VEC) model was estimated in order to analyze the causal relationships among balance of trade, investment (both national and foreign), and economic growth. The results helped us to discuss the mechanisms considered within the mercantilist literature to relate a positive balance of trade and economic growth. Particularly, the estimation suggests that the causality mechanism between the variables is closer to a financial mercantilist or developmental explanation or rather than a monetarist mercantilist approach. That is, the positive effect of the commercial balance on economic growth in China seems related to the increase of national investment, instead of the attraction of foreign direct investment

Convergencia entre las economías de México y EUA

Este trabajo analiza el proceso de convergencia del ingreso por habitante de EUA y de México de 1954 a 2008. Se encuentra un punto de ruptura en la evolución de esta relación en el último trimestre de 1982; esto llevó a analizar la brecha entre los dos ingresos, durante dos períodos, y se observa que la brecha durante el período 1983-2008 es significativamente mayor que durante el período 1954-1982. Luego, se estudia el proceso de convergencia cotejando que estas variables estuvieran cointegradas y verificando la estabilidad de los parámetros. Cabe destacar que durante el período de 1954- 2008 se dieron claramente dos períodos de cointegración, el de 1954-1982 y el de 1992-2008. Durante el primer período (1954-1982) se dio un proceso de convergencia absoluta, un proceso de alcance “catching up”. Durante el segundo período (1992-2008) se encuentra cointegración y estabilidad en los parámetros, lo que indica una convergencia estable pero incompleta en niveles menores a los registrados durante el primer período. El trabajo también ofrece una interpretación de estos resultados, con el propósito de fomentar el debate sobre las causas y soluciones del estancamiento económico de México. Clasificación JEL: 054, 011, E22, F43

New data on the distribution and natural history of the lesser grison (Galictis cuja), hog-nosed skunk (Conepatus chinga) and culpeo (Pseudalopex culpaeus) in northwestern Argentina

We present a total of 190 new distribution records of three little-known mammalian carnivores (Conepatus chinga; Galictis cuja,and Lycalopex culpaeus) obtained using camera trap techniques and direct observation in the highlands of Jujuy province, northwestern Argentina. These new records extend the present known distributions of these three species to the west of the province and to higher altitudes, and provide additional information on habitat association and activity patterns.Fil: Tellaeche, Cintia Gisele. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Cátedra de Fisiología Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reppucci, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Cátedra de Fisiología Animal; ArgentinaFil: Luengos Vidal, Estela Maris. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Cátedra de Fisiología Animal; ArgentinaFil: Lucherini, Mauro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Cátedra de Fisiología Animal; Argentin

Accuracy Evaluation of Dense Matching Techniques for Casting Part Dimensional Verification

Product optimization for casting and post-casting manufacturing processes is becoming compulsory to compete in the current global manufacturing scenario. Casting design, simulation and verification tools are becoming crucial for eliminating oversized dimensions without affecting the casting component functionality. Thus, material and production costs decrease to maintain the foundry process profitable on the large-scale component supplier market. New measurement methods, such as dense matching techniques, rely on surface texture of casting parts to enable the 3D dense reconstruction of surface points without the need of an active light source as usually applied with 3D scanning optical sensors. This paper presents the accuracy evaluation of dense matching based approaches for casting part verification. It compares the accuracy obtained by dense matching technique with already certified and validated optical measuring methods. This uncertainty evaluation exercise considers both artificial targets and key natural points to quantify the possibilities and scope of each approximation. Obtained results, for both lab and workshop conditions, show that this image data processing procedure is fit for purpose to fulfill the required measurement tolerances for casting part manufacturing processes.This research was partially funded by ESTRATEUS project (Reference IE14-396). given are accurate and use the standard spelling of funding agency names at https://search.crossref.org/funding, any errors may affect your future funding

Privacy Preserving Multi-Server k-means Computation over Horizontally Partitioned Data

The k-means clustering is one of the most popular clustering algorithms in data mining. Recently a lot of research has been concentrated on the algorithm when the dataset is divided into multiple parties or when the dataset is too large to be handled by the data owner. In the latter case, usually some servers are hired to perform the task of clustering. The dataset is divided by the data owner among the servers who together perform the k-means and return the cluster labels to the owner. The major challenge in this method is to prevent the servers from gaining substantial information about the actual data of the owner. Several algorithms have been designed in the past that provide cryptographic solutions to perform privacy preserving k-means. We provide a new method to perform k-means over a large set using multiple servers. Our technique avoids heavy cryptographic computations and instead we use a simple randomization technique to preserve the privacy of the data. The k-means computed has exactly the same efficiency and accuracy as the k-means computed over the original dataset without any randomization. We argue that our algorithm is secure against honest but curious and passive adversary.Comment: 19 pages, 4 tables. International Conference on Information Systems Security. Springer, Cham, 201

External and skull morphology of the Andean cat and Pampas cat: New data from the high Andes of Argentina

Andean and Pampas cats are 2 Neotropical small felids of the genus Leopardus. Until now, most of the scarce morphometric data published for these felids, especially the rare Andean cat (L. jacobita), were obtained from museum skins and skulls of undetermined sex. Here, we present morphological data from Pampas cats (L. colocolo) and the largest sample of live Andean cats (5 Andean cats and 6 Pampas cats) captured in the Argentine High Andes. We provide a craniometric analysis of all available adult skulls of Andean cats, including the first known female specimens of Andean and Pampas cats (n = 42). We nearly double the number of published external measurements for live Andean cats, and provide measurements and photos of all available skulls of adult Andean cats, including 2 new skulls with known sex. The data show that Andean cats are larger than Pampas cats and morphometric differences may be related to sexual dimorphism in both species. Principal component analysis of skull measurements showed almost complete separation of Andean and Pampas cats.Fil: Tellaeche, Cintia Gisele. Universidad Nacional de Jujuy. Instituto de Ecorregiones Andinas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Ecorregiones Andinas; Argentina. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias. Centro de Estudios Ambientales Territoriales y Sociales; ArgentinaFil: Reppucci, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Administración de Parques Nacionales. Delegación Regional del Noroeste; ArgentinaFil: Morales, Miriam Mariana. Universidad Nacional de Jujuy. Instituto de Ecorregiones Andinas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Ecorregiones Andinas; Argentina. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias. Centro de Estudios Ambientales Territoriales y Sociales; ArgentinaFil: Luengos Vidal, Estela Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Lucherini, Mauro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentin

Filling a gap in Andean Cat Leopardus jacobita (Cornalia, 1865) (Mammalia: Carnivora: Felidae) distribution range: New record in La Rioja province, Argentina

A pelt of an Andean Cat specimen was discovered in La Rioja Province, Argentina, a region with no previous data recorded, located in a large distribution gap between the two currently identified evolutionarily significant units (ESU). This new record not only improves our knowledge about the species distribution but can also provide relevant genetic information for a better understanding of the relationship between the two ESU.Fil: Tellaeche, Cintia Gisele. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias. Centro de Estudios Ambientales Territoriales y Sociales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Jujuy. Universidad Nacional de Jujuy. Centro de Investigaciones y Transferencia de Jujuy; ArgentinaFil: Guerisoli, Maria de Las Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Napolitano, Constanza. Universidad de Los Lagos; ChileFil: Di Nucci, Dante Luis. Fundación de Historia Natural Félix de Azara; ArgentinaFil: Reppucci, Juan Ignacio. Administración de Parques Nacionales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentin

Walk-through programming for robotic manipulators based on admittance control

The present paper addresses the issues that should be covered in order to develop walk-through programming techniques (i.e. a manual guidance of the robot) in an industrial scenario. First, an exact formulation of the dynamics of the tool the human should feel when interacting with the robot is presented. Then, the paper discusses a way to implement such dynamics on an industrial robot equipped with an open robot control system and a wrist force/torque sensor, as well as the safety issues related to the walk-through programming. In particular, two strategies that make use of admittance control to constrain the robot motion are presented. One slows down the robot when the velocity of the tool centre point exceeds a specified safety limit, the other one limits the robot workspace by way of virtual safety surfaces. Experimental results on a COMAU Smart Six robot are presented, showing the performance of the walk-through programming system endowed with the two proposed safety strategies

Close Range Photogrammetry for Direct Multiple Feature Positioning Measurement without Targets

The main objective of this study is to present a new method to carry out measurements so as to improve the positioning verification step in the wind hub part dimensional validation process. This enhancement will speed up the measuring procedures for these types of parts. An industrial photogrammetry based system was applied to take advantage of its results, and new functions were added to existing capabilities. In addition to a new development based on photogrammetry modelling and image processing, a measuring procedure was defined based on optical and vision system considerations. A validation against a certified procedure by means of a laser-tracker has also been established obtaining deviations of ±0.125 μm/m