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Journal articles on the topic 'Matrice 100'

Author: Grafiati

Published: 28 June 2021

Last updated: 5 February 2022

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1

Maya-Gress, Kristian Freyri, Raúl Villafuerte-Segura, Hugo Romero-Trejo, and Miguel Ángel Bernal-Reza. "Puesta en operación y modelado de un cuatrirotos: Matrice 100 de DJI." Pädi Boletín Científico de Ciencias Básicas e Ingenierías del ICBI 9, no. 17 (July 5, 2021): 67–75. http://dx.doi.org/10.29057/icbi.v9i17.6462.

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En la actualidad el empleo de vehículos aéreos no tripulados (VANT) es muy recurrente en diversas aplicaciones industriales, comerciales, ambientales, académicas, investigación, entre otras. Uno de los temas centrales de estos vehículos es su correcta manipulación/control en ausencia del ser humano. Sin embargo, esto no se puede alcanzar sin la puesta en operación y el empleo de modelos matemáticos. En este manuscrito se presenta la puesta en operación del VANT conocido como Matrice 100 de DJI, además del empleo de las técnicas más recurrente encontradas en la literatura para la obtención de su modelo matemático correspondiente. Este VANT es una plataforma experimental con base de fibra de carbón y cuatro rotores, cuenta con un software (simulador de vuelo) de arquitectura abierta para la comunicación/manipulación; desarrollado en el entorno integral libre Android Studio. Para el modelo matemático se considera una configuración en CRUZ y se emplea la metodología propuesta por Euler-Lagrange para describir las dinámicas traslacionales y rotacionales caracterizando las energías cinéticas y potenciales involucradas, teniendo como resultado un modelo no lineal subactuado de orden doce. Para corroborar el buen funcionamiento y la manipulación de la plataforma experimental; así como su correspondencia con el modelo matemático, se presentan simulaciones desarrolladas en Simulink-Matlab y el simulador de vuelo del fabricante, además de pruebas experimentales. Para lo anterior, se emplea un control clásico PD sintonizado solo para alcanzar una altura z en el VANT (considerando solo dinámicas traslacionales).

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2

Sèbe, Gilles. "Fonctionnalisation chimique des fibres pour le contrôle de l'interface fibre/matrice des composites à renforts naturels." Revue des composites et des matériaux avancés 16, no. 1 (April 23, 2006): 89–100. http://dx.doi.org/10.3166/rcma.16.89-100.

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3

Çakır, Abdülkadir, and Seyit Akpancar. "ROS-Based Control of the DJI Matrice 100 Robot with QR Images Obtained from DJI Guidance." International Journal of Engineering Trends and Technology 68, no. 1 (January 25, 2020): 45–50. http://dx.doi.org/10.14445/22315381/ijett-v68i1p206.

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4

Varango, Concettina, Francesca Musarella, Mara Cella, and Antonella Varango. "Prospettiva e Valore della matrice Cheratinica nella valutazione dell'utilizzo di Nuove Sostanze Psicoattive nella popolazione che afferisce ai SERD." MISSION, no. 53 (May 2020): 39–44. http://dx.doi.org/10.3280/mis53-2020oa9242.

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Questo articolo nasce dall'esigenza di informare un più ampio pubblico sul pericolo rappresentato da queste sostanze, far conoscere le NPS (Novel Psychoactive substances) agli operatori del settore (personale di laboratorio, personale delle unità di emergenza/ urgenza, operatori sanitari, ricercatori, ecc.) al fine di agevolare l'analisi di campioni sconosciuti e divulgare i dati scientifici che cominciano ad emergere da studi clinici e preclinici sui loro effetti tossici e farmacologici. Dal 2009 sono comparsi nel gruppo delle N.P.S., i nuovi oppioidi sintetici, molecole estremamente potenti che comportano una seria minaccia per la salute pubblica. Si tratta di prodotti dalla notevole potenza (il fentanyl, per esempio, capostipite di questa famiglia, ha un'azione circa 100 volte maggiore rispetto a quella della morfina) che vengono utilizzati sia per sé sia come adulteranti di partite di sostanze classiche, soprattutto eroina, causando scie di decessi per overdose. 

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B., Adithya, Pavan N., Young Chai, and Ashok Patil. "Inspired by Human Eye: Vestibular Ocular Reflex Based Gimbal Camera Movement to Minimize Viewpoint Changes." Symmetry 11, no. 1 (January 16, 2019): 101. http://dx.doi.org/10.3390/sym11010101.

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Human eyeballs move relative to the head, resulting in optimal changes in the viewpoint. We tested similar vestibular ocular reflex (VOR)-based movement on Zenmuse-X3 gimbal camera relative to pre-defined YAW movements of the DJI Matrice-100 unmanned aerial vehicle (UAV). Changes in viewpoint have various consequences for visual and graphical rendering. Therefore, this study investigated how to minimize these changes. OpenGL visualization was performed to simulate and measure viewpoint changes using the proposed VOR-based eyeball movement algorithm and compared with results of VOR based gimbal movement. The gimbal camera was setup to render images (scenes) on flat monitors. Positions of pre-fixed targets in the images were used to measure the viewpoint changes. The proposed approach could successfully control and significantly reduce the viewpoint changes and stabilize the image to improve visual tracking of targets on flat monitors. The proposed method can also be used to render real-time camera feed to a head-mounted display (HMD) in an ergonomically pleasing way.

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6

Wang, Hanzhang, and Yisha Liu. "A low-cost autonomous navigation system for a quadrotor in complex outdoor environments." International Journal of Advanced Robotic Systems 17, no. 1 (January 1, 2020): 172988142090515. http://dx.doi.org/10.1177/1729881420905150.

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In this article, we design a low-cost navigation system for a quadrotor working in unknown outdoor environments. To reduce the computing burden of the quadrotor, we build a separated system and transfer the computing resources from onboard side to ground station side. Both sides’ communication is guaranteed by 5G wireless networks. We utilize a stereo camera to acquire point clouds and build Octomap for the quadrotor’s navigation. Then, the trajectory is generated in two stages. In the first stage, a modified RRT*-CONNECT algorithm is adopted to generate a set of collision-free waypoints. In the second stage, a curve fitting algorithm is utilized to get a smooth piecewise Bezier trajectory. The advantage of the proposed method is to optimize the path into a safe, smooth, and dynamically feasible trajectory in real time. The modules of the state estimation, dense mapping, and motion planning are integrated into a DJI Matrice 100 quadrotor. Finally, simulation and experiments are both conducted to show the validity and practicality of our method.

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Carbone, Carlos, Oscar Garibaldi, and Zohre Kurt. "Swarm Robotics as a Solution to Crops Inspection for Precision Agriculture." KnE Engineering 3, no. 1 (February 11, 2018): 552. http://dx.doi.org/10.18502/keg.v3i1.1459.

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This paper summarizes the concept of swarm robotics and its applicability to crop inspections. To increase the agricultural yield it is essential to monitor the crop health. Hence, precision agriculture is becoming a common practice for farmers providing a system that can inspect the state of the plants (Khosla and others, 2010). One of the rising technologies used for agricultural inspections is the use of unmaned air vehicles (UAVs) which are used to take aerial pictures of the farms so that the images could be processed to extract data about the state of the crops (Das et al., 2015). For this process both fixed wings and quadrotors UAVs are used with a preference over the quadrotor since it’s easier to operate and has a milder learning curve compared to fixed wings (Kolodny, 2017). UAVs require battery replacement especially when the environmental conditions result in longer inspection times (“Agriculture - Maximize Yields with Aerial Imaging,” n.d., “Matrice 100 - DJI Wiki,” n.d.). As a result, inspection systems for crops using commercial quadrotors are limited by the quadrotor´s maximum flight speed, maximum flight height, quadrotor´s battery time, crops area, wind conditions, etc. (“Mission Estimates,” n.d.).Keywords: Swarm Robotics, Precision Agriculture, Unmanned Air Vehicle, Quadrotor, inspection.

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Mawrence, Raphael, Sandra Munniks, and João Valente. "Calibration of Electrochemical Sensors for Nitrogen Dioxide Gas Detection Using Unmanned Aerial Vehicles." Sensors 20, no. 24 (December 20, 2020): 7332. http://dx.doi.org/10.3390/s20247332.

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For years, urban air quality networks have been set up by private organizations and governments to monitor toxic gases like NO2. However, these networks can be very expensive to maintain, so their distribution is usually widely spaced, leaving gaps in the spatial resolution of the resulting air quality data. Recently, electrochemical sensors and their integration with unmanned aerial vehicles (UAVs) have attempted to fill these gaps through various experiments, none of which have considered the influence of a UAV when calibrating the sensors. Accordingly, this research attempts to improve the reliability of NO2 measurements detected from electrochemical sensors while on board an UAV by introducing rotor speed as part of the calibration model. This is done using a DJI Matrice 100 quadcopter and Alphasense sensors, which are calibrated using regression calculations in different environments. This produces a predictive r-squared up to 0.97. The sensors are then calibrated with rotor speed as an additional variable while on board the UAV and flown in a series of flights to evaluate the performance of the model, which produces a predictive r-squared up to 0.80. This methodological approach can be used to obtain more reliable NO2 measurements in future outdoor experiments that include electrochemical sensor integration with UAV’s.

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Lebas, E., C. Bretagnolle, N. Rafrafi, L. Beaumont, and R. Megard. "Cartographie des risques a priori du circuit du médicament dans les structures extrahospitalières d’un centre hospitalier spécialisé en psychiatrie : proposition d’un outil d’analyse." European Psychiatry 30, S2 (November 2015): S152. http://dx.doi.org/10.1016/j.eurpsy.2015.09.306.

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L’amélioration de la prise en charge médicamenteuse est un objectif constant des équipes en charge de la qualité et de la gestion des risques liés aux soins. En psychiatrie, le circuit du médicament concerne à la fois les secteurs intra et extrahospitaliers, pour lequel l’analyse des risques est parfois moins maîtrisée. L’objectif de ce travail est d’établir une cartographie des risques, a priori, du circuit du médicament du secteur extrahospitalier de notre établissement (800 lits) afin d’aboutir à l’élaboration de recommandations pour la sécurisation de ce circuit. Un état des lieux du fonctionnement du circuit du médicament en secteur extrahospitalier a été réalisé en collaboration avec la cellule qualité de janvier à juin 2015 au sein de 11 centres médico-psychologiques et 10 centres et/ou hôpitaux de jour. Les données recueillies lors de cette étude observationnelle ont été analysées selon la méthode AMDEC (analyse des modes de défaillance, de leurs effets, et de leur criticité). Après pondération (construction d’une matrice), les divers circuits ont été modélisés en logigrammes intégrant différents points (conciliation médicamenteuse, conditions de prescriptions, de délivrance, et d’administration) et comportant sept issues potentielles allant de la situation la plus à risque vers la plus sécurisée (pondérée à 100 %). Les étapes du circuit les plus critiques sont l’absence de conciliation, la non-informatisation des prescriptions et l’administration médicamenteuse sans prescription. Dans seulement 2 situations sur 28 (7 %) le circuit extrahospitalier est sécurisé à 100 % et dans 13 cas sur 28 (46 %), un niveau de sécurisation supérieur à 50 % (seuil d’acceptabilité défini) est atteint. Si le choix de la valeur seuil (50 %) et la pertinence d’un tel outil restent critiquables, ce travail préliminaire a permis la mise en évidence des situations les plus à risque, la création d’un groupe de travail pluridisciplinaire et l’élaboration de mesures correctives.

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Cholula, Uriel, Jorge A. da Silva, Thiago Marconi, J. Alex Thomasson, Jorge Solorzano, and Juan Enciso. "Forecasting Yield and Lignocellulosic Composition of Energy Cane Using Unmanned Aerial Systems." Agronomy 10, no. 5 (May 17, 2020): 718. http://dx.doi.org/10.3390/agronomy10050718.

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Crop monitoring and appropriate agricultural management practices of elite germplasm will enhance bioenergy’s efficiency. Unmanned aerial systems (UAS) may be a useful tool for this purpose. The objective of this study was to assess the use of UAS with true color and multispectral imagery to predict the yield and total cellulosic content (TCC) of newly created energy cane germplasm. A trial was established in the growing season of 2016 at the Texas A&M AgriLife Research Center in Weslaco, Texas, where 15 energy cane elite lines and three checks were grown on experimental plots, arranged in a complete block design and replicated four times. Four flights were executed at different growth stages in 2018, at the first ratoon crop, using two multi-rotor UAS: the DJI Phantom 4 Pro equipped with RGB camera and the DJI Matrice 100, equipped with multispectral sensor (SlantRange 3p). Canopy cover, canopy height, NDVI (Normalized Difference Vegetation Index), and ExG (Excess Green Index) were extracted from the images and used to perform a stepwise regression to obtain the yield and TCC models. The results showed a good agreement between the predicted and the measured yields (R2 = 0.88); however, a low coefficient of determination was found between the predicted and the observed TCC (R2 = 0.30). This study demonstrated the potential application of UAS to estimate energy cane yield with high accuracy, enabling plant breeders to phenotype larger populations and make selections with higher confidence.

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11

St-Onge, Denis A., and Isabelle McMartin. "La Moraine du Lac Bluenose (Territoires du Nord-Ouest), une moraine à noyau de glace de glacier." Géographie physique et Quaternaire 53, no. 2 (October 2, 2002): 287–95. http://dx.doi.org/10.7202/005696ar.

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Résumé Au sud du détroit du Dolphin et de l'Union, dans les Territoires du Nord-Ouest, des crêtes morainiques hautes de 100 m, composées de till à gros blocs marquent l'emplacement d'un front glaciaire à l'est et au nord du lac Bluenose. Les principales crêtes sont soit massives, soit composites avec de petites crêtes secondaires à leur sommet. En amont glaciaire (est) des crêtes, les formes de relief les plus fréquentes sont des collines recouvertes de blocs dont la hauteur atteint 60 m et des monticules entre lesquels se trouvent de nombreux lacs. Un important glissement de terrain au cœur de la moraine expose de la glace riche en sédiments, enfouie sous 3 m de till. Ce diamicton à matrice sabloneuse et riche en blocs exhibe une structure en colonnes et une fissilité prismatique. La glace enfouie qui incorpore des blocs et des cailloux est zonée, ce qui permet de déceler des plis et des déformations plus complexes. Le contact entre la glace enfouie et le diamicton est net, sub-horizontal et discordant. La glace est interprétée comme étant la partie basale d'un glacier enfouie par des sédiments glacigéniques, surtout du till. Dans une zone à écoulement à contre pente de la partie frontale de l'inlandsis du Wisconsinen supérieur des chevauchements ont transporté des sédiments qui ont recouvert la glace morte à la marge du front de glace active. Nous croyons que dans l'éventualité où un réchauffement climatique causerait la fonte de la glace enfouie, laquelle représente un volume important de la Moraine du Lac Bluenose, le relief serait transformé en un paysage bosselé semblable à celui qui existe dans des régions plus méridionales du Canada central.

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Doughty, Cheryl, and Kyle Cavanaugh. "Mapping Coastal Wetland Biomass from High Resolution Unmanned Aerial Vehicle (UAV) Imagery." Remote Sensing 11, no. 5 (March 6, 2019): 540. http://dx.doi.org/10.3390/rs11050540.

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Salt marsh productivity is an important control of resiliency to sea level rise. However, our understanding of how marsh biomass and productivity vary across fine spatial and temporal scales is limited. Remote sensing provides a means for characterizing spatial and temporal variability in marsh aboveground biomass, but most satellite and airborne sensors have limited spatial and/or temporal resolution. Imagery from unmanned aerial vehicles (UAVs) can be used to address this data gap. We combined seasonal field surveys and multispectral UAV imagery collected using a DJI Matrice 100 and Micasense Rededge sensor from the Carpinteria Salt Marsh Reserve in California, USA to develop a method for high-resolution mapping of aboveground saltmarsh biomass. UAV imagery was used to test a suite of vegetation indices in their ability to predict aboveground biomass (AGB). The normalized difference vegetation index (NDVI) provided the strongest correlation to aboveground biomass for each season and when seasonal data were pooled, though seasonal models (e.g., spring, r2 = 0.67; RMSE = 344 g m−2) were more robust than the annual model (r2 = 0.36; RMSE = 496 g m−2). The NDVI aboveground biomass estimation model (AGB = 2428.2 × NDVI + 120.1) was then used to create maps of biomass for each season. Total site-wide aboveground biomass ranged from 147 Mg to 205 Mg and was highest in the spring, with an average of 1222.9 g m−2. Analysis of spatial patterns in AGB demonstrated that AGB was highest in intermediate elevations that ranged from 1.6–1.8 m NAVD88. This UAV-based approach can be used aid the investigation of biomass dynamics in wetlands across a range of spatial scales.

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Pasichnyk, N. A., V. P. Lysenko, and O. O. Opryshko. "Methodical approaches to plant identification in high-resolution images in multispectral monitoring using UAVS." PLANT AND SOIL SCIENCE 12, no. 2 (2021): 47–53. http://dx.doi.org/10.31548/agr2021.02.047.

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Crop management used in these technologies is one of the main trends in the modernization of agricultural technologies. To implement crop management, growers need accessible and effective information about the state of crops. The aim of the work is to develop a method of plant identification on multispectral images of high resolution for crops of continuous sowing on the example of winter wheat. The research was conducted on 03/17/2019 on winter wheat crops in the tillering vegetation phase, Mukan variety in production fields near the village of Horodyshche, Kyiv region. Aerial monitoring from a height of 100 meters was carried out using a spectral complex Slantrange 3p, mounted on a UAV UAV DJI Matrice 600. To extract the reference graphics data from Slantview made a copy of the screen in full screen mode of the image window. Statistical processing of graphical data of spectral monitoring results was performed in MathCad. It was found that the reliable establishment of the spectral portrait of the soil for its pixel-by-pixel filtering from multispectral images is a difficult task because its color significantly depends on the state of moisture, which may differ in open and shaded by plants. A more promising way to eliminate random inclusions is to use a spectral portrait of plants based on the intensity ratios of its spectral components. A promising parameter for assessing the condition of crops is to assess their area of heir horizontal surface, which can be determined by pixel analysis of the image. A filtering option is proposed, which, as in the solutions implemented in Slantview software, needs to be debugged. In further researches it is expedient to consider questions of methodical maintenance of an estimation of quality of a filtration of data of spectral monitoring of vegetation.

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BALLICO, Edoardo. "The numerical range of matrices over F4." TURKISH JOURNAL OF MATHEMATICS 43, no. 2 (March 27, 2019): 955–64. http://dx.doi.org/10.3906/mat-1810-100.

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Yeom, Junho, Jinha Jung, Anjin Chang, Akash Ashapure, Murilo Maeda, Andrea Maeda, and Juan Landivar. "Comparison of Vegetation Indices Derived from UAV Data for Differentiation of Tillage Effects in Agriculture." Remote Sensing 11, no. 13 (June 29, 2019): 1548. http://dx.doi.org/10.3390/rs11131548.

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Unmanned aerial vehicle (UAV) platforms with sensors covering the red-edge and near-infrared (NIR) bands to measure vegetation indices (VIs) have been recently introduced in agriculture research. Consequently, VIs originally developed for traditional airborne and spaceborne sensors have become applicable to UAV systems. In this study, we investigated the difference in tillage treatments for cotton and sorghum using various RGB and NIR VIs. Minimized tillage has been known to increase farm sustainability and potentially optimize productivity over time; however, repeated tillage is the most commonly-adopted management practice in agriculture. To this day, quantitative comparisons of plant growth patterns between conventional tillage (CT) and no tillage (NT) fields are often inconsistent. In this study, high-resolution and multi-temporal UAV data were used for the analysis of tillage effects on plant health and the performance of various vegetation indices investigated. Time series data over ten dates were acquired on a weekly basis by RGB and multispectral (MS) UAV platforms: a DJI Phantom 4 Pro and a DJI Matrice 100 with the SlantRange 3p sensor. Ground reflectance panels and an ambient illumination sensor were used for the radiometric calibration of RGB and MS orthomosaic images, respectively. Various RGB and NIR-based vegetation indices were then calculated for the comparison between CT and NT treatments. In addition, a one-tailed Z-test was conducted to check the significance of VIs’ difference between CT and NT treatments. The results showed distinct differences in VIs between tillage treatments during the whole growing season. NIR-based VIs showed better discrimination performance than RGB-based VIs. Out of 13 VIs, the modified soil adjusted vegetation index (MSAVI) and optimized soil adjusted vegetation index (OSAVI) showed better performance in terms of quantitative difference measurements and the Z-test between tillage treatments. The modified green red vegetation index (MGRVI) and excess green (ExG) showed reliable separability and can be an alternative for economic RGB UAV application.

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Kouonon, Léonie Clémence, Kouamé Guillaume Koffi, Koffi Adjoumani, Anouman Désirée Sandrine Mobio, and Koudougnon Alice Estère Goba. "Caractérisation phénotypique du néré (Parkia biglobosa (Jacq.) R. Br. ex G. Don, Fabaceae) dans trois types de savane de Côte d’Ivoire." International Journal of Biological and Chemical Sciences 14, no. 2 (May 12, 2020): 555–69. http://dx.doi.org/10.4314/ijbcs.v14i2.20.

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Afin de préserver les nombreux biens et services fournis par Parkia biglobosa (Jacq.) R. Br. ex G. Don, Fabaceae, il est fondamental de connaître la variabilité phénotypique de l’espèce pour sa domestication. L’objectif de cette étude est de déterminer des caractères morphologiques permettant d’identifier des arbres-plus dans les savanes de Côte d’Ivoire. La variabilité phénotypique d’arbres distants d’au moins 100 m des trois types de savane a été étudiée à travers 22 caractères quantitatifs relatifs aux troncs, feuilles, fruits et graines. La matrice de données obtenue a été analysée avec différents tests tels que MANOVA suivie de ANOVA 1, AFD et la CAH. Les paramètres permettant de distinguer les arbres selon leur origine sont : hauteur totale d’arbre, épaisseur graine, poids de graine et pulpe par fruit, longueur du fruit, longueur et épaisseur du pédicelle, longueur et épaisseur du pédoncule. Les arbres en savane guinéenne ont de longs et épais pédoncules, des pédicelles épais et de longs fruits. Les arbres en savane sub-soudanaise sont hauts avec des graines et pédicelles épais, un poids de graine et de pulpe par fruit en moyenne élevé alors que les arbres en savane soudanaise sont hauts avec un long pédoncule. Mots clés: Parkia biglobosa, néré, variabilité phénotypique, conservation, savane. English Title: Phenotypical caracterization of african locust bean (Parkia biglobosa (Jacq.) R. Br. ex G. Don, Fabaceae) from three savannahs types in Côte d’Ivoire To preserve goods and services provided by Parkia biglobosa (Jacq.) R. Br. ex G. Don, Fabaceae, it is essential to know the phenotypical variability of this species for domestication purpose. The objective of this study is to define morphological discriminant traits to identify tree-plus in the savannahs from Côte d'Ivoire. The phenotypical variability of trees distant at least 100 m from three types of savannah was studied through 22 quantitative traits related to trunks, leaves, fruits and seeds. Matrix data was analyzed with different tests such as MANOVA followed by ANOVA 1, AFD and CAH. Traits that allow distinguishing trees according to their origin are: total height, seed thickness, seed and pulp weight per fruit, fruit length, pedicel length and thickness, peduncle length and thickness. In the Guinean savannah, trees have long and thick peduncles, thick pedicels and long fruits. In Sub-Sudanese savannah, trees are tall with thick seeds and pedicels, high seeds and pulp weight per fruit while Sudanese savannah trees are tall with a long peduncle. Keywords: Parkia biglobosa, locust bean, phenotypical variability, conservation, savannah.

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Stępniak, Czesław. "Inverting covariance matrices." Discussiones Mathematicae Probability and Statistics 26, no. 2 (2006): 163. http://dx.doi.org/10.7151/dmps.1080.

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Ricci, Paolo Emilio. "A note on Q-matrices and higher order Fibonacci polynomials." Notes on Number Theory and Discrete Mathematics 27, no. 1 (March 2021): 91–100. http://dx.doi.org/10.7546/nntdm.2021.27.1.91-100.

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The results described in a recent article, relative to a representation formula for the generalized Fibonacci sequences in terms of Q-matrices are extended to the case of Fibonacci, Tribonacci and R-bonacci polynomials.

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Rassam, Daud W., and David J. Williams. "A relationship describing the shear strength of unsaturated soils." Canadian Geotechnical Journal 36, no. 2 (September 25, 1999): 363–68. http://dx.doi.org/10.1139/t98-102.

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A relationship describing the shear-strength profile of a desiccating soil deposit is essential for the purpose of analysis, especially when a numerical method is adopted where each zone in a discretised grid is assigned an elevation-dependent shear-strength value. The matric-suction profile of a desiccating soil deposit is nonlinear. Up to the air-entry value, an increase in matric suction is associated with a linear increase in shear strength. Beyond air entry, as the soil starts to desaturate, a nonlinear increase in shear strength occurs. The soil-water characteristic curve is stress dependent, as is the shear-strength gain as matric suction increases. In this paper, a three-dimensional, nonlinear regression analysis showed that a power-additive function is suitable to describe the variation of the shear strength of unsaturated soils with matric suction. The proposed function incorporates the effect of normal stress on the contribution of matric suction to the shear strength.Key words: air-entry value, matric suction, nonlinear regression, soil-water characteristic curve, tailings, unsaturated shear strength.

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Gómez Plata, Adrián Ricardo. "Uso de la descomposición TOEPLITZ en la estratificación de matrices." Ciencia e Ingeniería Neogranadina 17, no. 1 (June 1, 2007): 5–12. http://dx.doi.org/10.18359/rcin.1080.

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Las matrices Normales N son una subvariedad estratificada en forma de estrella de R^[(2n)^2]; se prefiere para propósitos prácticos, tener en forma concreta como es la estratificación de algunas matrices. Se presentará aquí algunos teoremas que permiten decantar una estratificación de las matrices Normales hecha por medio de la descomposición de Toeplitz y que conlleva a realizar el cálculo de valores propios usando el método Hermitiano de Lanczos o el método de Arnoldo según Huthanen [4].

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Han, Shao-Rong, Hai Gong, Yan-Ming Wang, Xiao-Yan Lv, Cong Zhang, An-Na Tong, Guang-Hui Yuan, and Bao-Yi Zhang. "The Preparation of Matrine Liposome and Its Antiglioma Activity Study." Journal of Chemistry 2014 (2014): 1–5. http://dx.doi.org/10.1155/2014/317320.

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The aim of the study was to study the preparation of matrine liposome and its activity for resisting cells, to study the preparation of matrine liposome by orthogonal design, and to observe the inhibiting effect of matrine on glioma through MTT method, Flow Cytometer, and electron microscope. The results showed that we take the encapsulation efficiency as the index; the optimal preparation of matrine liposome is 100 mg of lecithin, 40 mg of cholesterol, phosphate buffered saline (PBS) with pH value 6.4, and 40 mg of matrine. The result of MTT testing is shown that the tested group with medium and high dosage (0.75, 1.0, 1.25 mg/L) of matrine has significant inhibiting rate to the growth of BT 325 cells. TheAvalue in tested group with medium and high dosage is up to0.19±0.03. The methods of Flow Cytometer and electron microscope prove that matrine can inhibit the growth of BT 325 cells. Matrine is active in inhibiting brain glioma.

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Meilani, Inge, Harianto Rahardjo, Eng-Choon Leong, and Delwyn G. Fredlund. "Mini suction probe for matric suction measurements." Canadian Geotechnical Journal 39, no. 6 (December 1, 2002): 1427–32. http://dx.doi.org/10.1139/t02-101.

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A modified triaxial apparatus with mini suction probes was fabricated to study the matric suction along the specimen height during unsaturated triaxial testing. Three mini suction probes were placed at 3/4, 1/2, and 1/4 height of the specimen, each at 120° apart in the lateral direction. This paper presents the development of the mini probe for matric suction measurements. Evaluation of the performance shows that the fabricated mini probe provides a rapid response and accurate reading under negative and positive pore-water pressure changes. Matric suctions as high as 400 kPa were successfully measured on soil specimens over a time span of 15 h. On the other hand, the mini suction probes were also found to be able to measure a matric suction of 200 kPa for a longer period of 155 h.Key words: matric suction, mini suction probe, triaxial, unsaturated soils, mid-height pore-water pressure measurement.

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23

Sidorov, Alexey A., Mikhail A. Kiskin, Alexander E. Baranchikov, Vladimir K. Ivanov, and Igor L. Eremenko. "Methods for Synthesis of Molecular Materials with Unique Physical Properties." Vestnik RFFI, no. 2 (June 25, 2019): 82–100. http://dx.doi.org/10.22204/2410-4639-2019-102-02-82-100.

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The authors discovered and investigated new types of stable heterometallic carboxylate complexes in which divalent transition metal atoms of the 4th period of the Periodic Table of Chemical Elements (V, Co, Ni, Cu, Zn) combine with atoms of lithium, magnesium, calcium or rare earth elements. These polynuclear heterometallic compounds retain their structure under conditions when the homometallic compounds of these transition metals decompose to mononuclear complexes. The different metals combination in one molecule allows us to use the obtained heterometallic compounds for producing disperse and film oxide materials, and bimetallic oxide catalysts. The stability of the complexes allows to immobilize them in various matrices and to assemble 3D polymer structures on their base. Since the metal ions under consideration (V, Co, Ni, Cu, Zn) are capable to form isostructural heterometallic compounds, it becomes possible to obtain compounds within a single structural type with a given combination of physical properties, determined by the nature of the metal ions.

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24

Eliahou, Shalom, and Michel Kervaire. "Modular sequences and modular Hadamard matrices." Journal of Combinatorial Designs 9, no. 3 (2001): 187–214. http://dx.doi.org/10.1002/jcd.1007.

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25

Petala, Athanasia, Athanasia Nasiou, Dionissios Mantzavinos, and Zacharias Frontistis. "Photocatalytic Evaluation of Ag2CO3 for Ethylparaben Degradation in Different Water Matrices." Water 12, no. 4 (April 20, 2020): 1180. http://dx.doi.org/10.3390/w12041180.

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The present study examines the photocatalytic properties of silver carbonate (Ag2CO3) for ethyl paraben (EP) degradation under simulated solar irradiation. Ag2CO3 was prepared according to a solution method and its physicochemical characteristics were studied by means of X-ray diffraction (XRD), the Brunauer–Emmett–Teller (BET) method, diffuse reflectance spectroscopy (DRS), and transmission electron microscopy (TEM). Complete EP (0.5 mg/L) removal was achieved after 120 min of irradiation with the use of 750 mg/L Ag2CO3 in ultrapure water (UPW), with EP degradation following pseudo-first-order kinetics. The effect of several experimental parameters was investigated; increasing catalyst concentration from 250 mg/L to 1000 mg/L led to an increase in EP removal, while increasing EP concentration from 0.25 mg/L to 1.00 mg/L slightly lowered kapp from 0.115 min−1 to 0.085 min−1. Experiments carried out with the use of UV or visible cut-off filters showed sufficient EP degradation under visible irradiation. A series of experiments were performed in real water matrices such as bottled water (BW) and wastewater (WW), manifesting Ag2CO3’s equally high photocatalytic activity for EP degradation. To interpret these results different concentrations of inorganic anions (bicarbonate 100–500 mg/L, chloride 100–500 mg/L) present in aqueous media, as well as 10 mg/L organic matter in the form of humic acid (HA), were added sequentially in UPW. Results showed accelerating effects on EP degradation for the lowest concentrations tested in all cases.

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Kerpedjiev, Peter, Jes Frellsen, Stinus Lindgreen, and Anders Krogh. "Adaptable probabilistic mapping of short reads using position specific scoring matrices." BMC Bioinformatics 15, no. 1 (2014): 100. http://dx.doi.org/10.1186/1471-2105-15-100.

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27

Efimov, Mikhail A., and Alexander E. Guterman. "Monotone maps on diagonalizable matrices." Mathematical Inequalities & Applications, no. 4 (2014): 1441–52. http://dx.doi.org/10.7153/mia-17-106.

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28

Jackson, Donald A., and Keith M. Somers. "Are probability estimates from the permutation model of Mantel's test stable?" Canadian Journal of Zoology 67, no. 3 (March 1, 1989): 766–69. http://dx.doi.org/10.1139/z89-108.

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Matrix comparison tests (i.e., Mantel's test or quadratic assignment) are employed with increasing frequency to measure the concordance between genetic, behavioural, morphological, ecological, and geographic distances. Such tests compare an observed measure of matrix association with a null distribution derived from a randomly generated subset of all possible permutations of one of the original matrices. Typically, 500–2000 randomly permutated matrices are used to generate the statistical distribution and thereby estimate the probability of obtaining an observed association between two matrices. We demonstrate that a considerable error (i.e., 5–6%) may be associated with probability estimates based on such low numbers of permutations. To ensure the stability of the probability estimates (i.e., increase the reliability of the test), we recommend the use of a minimum of 10 000 permutations, and 100 000 permutations if the observed probability approaches a critical significance value (e.g., 0.05).

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29

Zhao, Wen Ling. "The Non-Singularity on the Level-2(r₁,r₂)-Circulant Matrices of Type (n₁,n₂)." Advanced Materials Research 108-111 (May 2010): 657–62. http://dx.doi.org/10.4028/www.scientific.net/amr.108-111.657.

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As special matrices, it is well known that the circulant matrices are very important. Various types of circulant matrices have been applied in such as signal dealing and oil exploration, and so on in recent years. In this paper, motivated by [1], we give some discriminations by using only the elements in the first row of the Level- -Circulant Matrices of Type and parameter on non singularity, and give two examples at last.

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30

Radhakrishnan, M., N. Elumalai, R. Perumal, and R. Arulprakasam. "Idempotent circulant matrices." Journal of Physics: Conference Series 1000 (April 2018): 012154. http://dx.doi.org/10.1088/1742-6596/1000/1/012154.

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31

Han, Gui Chun. "New Criteria for Nonsingular H-Matrices." Advanced Materials Research 1006-1007 (August 2014): 1043–46. http://dx.doi.org/10.4028/www.scientific.net/amr.1006-1007.1043.

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The concept of quasi-double diagonally dominant matrices is introduced, and it’s equivalent representation is given. As its application, one sufficient condition for nonsingular H-matrices is obtained. The effectiveness of the proposed criterion for nonsingular H-matrices is showed by numerical example.

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32

Béal, C., F. Fonseca, A. Thomas, and Mireca Marin. "Caractérisation et lyophilisation de matrices fromagères." Sciences des Aliments 26, no. 1 (February 28, 2006): 89–102. http://dx.doi.org/10.3166/sda.26.89-102.

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33

Fyodorov, Y. V. "Level Curvature Distribution: from Bulk to the Soft Edge of Random Hermitian Matrices." Acta Physica Polonica A 120, no. 6A (December 2011): A—100—A—113. http://dx.doi.org/10.12693/aphyspola.120.a-100.

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34

Berkolaiko, G. "Spectral gap of doubly stochastic matrices generated from equidistributed unitary matrices." Journal of Physics A: Mathematical and General 34, no. 22 (May 24, 2001): L319—L326. http://dx.doi.org/10.1088/0305-4470/34/22/101.

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35

Gao, Hui Shuang. "Discussion for Block H-Matrices." Advanced Materials Research 1006-1007 (August 2014): 1039–42. http://dx.doi.org/10.4028/www.scientific.net/amr.1006-1007.1039.

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In this paper, a new sufficient and necessary condition for judging block strictly-double diagonally dominant matrices is given firstly. By this theorem, some new practical criteria for nonsingular blockH-matrices are obtained. In the end, the result effectiveness is illustrated by numerical examples.

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36

Golemac, Anka, and Tanja Vučičić. "New (100,45,20) symmetric designs and Bush-type Hadamard matrices of order 100." Discrete Mathematics 245, no. 1-3 (February 2002): 263–72. http://dx.doi.org/10.1016/s0012-365x(01)00309-0.

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37

Barker, George P., and Joyce J. Conklin. "Reflexive algebras of matrices." Rocky Mountain Journal of Mathematics 15, no. 1 (March 1985): 107–16. http://dx.doi.org/10.1216/rmj-1985-15-1-107.

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38

Gadiyar, H. Gopalkrishna, K. M. Sangeeta Maini, R. Padma, and H. S. Sharatchandra. "Entropy and Hadamard matrices." Journal of Physics A: Mathematical and General 36, no. 7 (February 5, 2003): L109—L112. http://dx.doi.org/10.1088/0305-4470/36/7/103.

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39

Lucas, Andrew, Mark Stalzer, and John Feo. "Parallel Implementation of Fast Randomized Algorithms for Low Rank Matrix Decomposition." Parallel Processing Letters 24, no. 01 (March 2014): 1450004. http://dx.doi.org/10.1142/s0129626414500042.

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We analyze the parallel performance of randomized interpolative decomposition by decomposing low rank complex-valued Gaussian random matrices of about 100 GB. We chose a Cray XMT supercomputer as it provides an almost ideal PRAM model permitting quick investigation of parallel algorithms without obfuscation from hardware idiosyncrasies. We obtain that on non-square matrices performance scales almost linearly with runtime about 100 times faster on 128 processors. We also verify that numerically discovered error bounds still hold on matrices two orders of magnitude larger than those previously tested.

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40

Jing-Min, Ye, He Hui-Qing, Jiang Xu-Hong, Liu Zhan-Mei, Cheng Xing-An, and He Zhao-Chang. "The crystal structure of a matrine derivative, 13-(4-Cl-pyrrole)-matrine, C18H26ClN4O." Zeitschrift für Kristallographie - New Crystal Structures 234, no. 4 (June 26, 2019): 785–86. http://dx.doi.org/10.1515/ncrs-2019-0105.

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41

Lv, Haixia, Suying Ma, Xiao Wang, and Xiaojun Shang. "Simultaneous Determination of Co-formulated Matrine and Secnidazole in Suppositories by Reverse Phase High Performance Liquid Chromatography." Tropical Journal of Pharmaceutical Research 12, no. 3 (June 17, 2016): 413–18. http://dx.doi.org/10.4314/tjpr.v12i3.21.

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Purpose: To develop and validate a new, simple, sensitive and accurate high performance liquid chromatographic (HPLC) method for the simulataneous determination of matrine and secnidazole in suppositories.Methods: The method involved using a SinoChoom ODS-BP C18 column (5 ƒÊm, 4.6 mm ~ 200 mm) and mobile phase consisting of acetonitrile.triethylamine (0.05 %) in 0.025 mol/L KH2PO4 (20:80, v/v).The flow rate was 1 mL/min and detection was monitored at 210 and 311 nm for matrine and secnidazole, respectively. Total run time was 10 min and the column was maintained at 35 oC.Results: The excipients in the suppository did not interfere with the drug peaks. Matrine was eluted at a retention time (RT) of 4.30 min while linearity for the quantification of drug was obtained in the concentration range of 10.0 - 100.0 ƒÊg/mL (r2 = 0.9991). Secnidazole was eluted at a retention time (tr) of 6.69 min and linearity for the quantification of the drug was obtained in the concentration range of 10.0 - 150.0 ƒÊg/mL (r2 = 0.9993). Intra- and inter-day variations were < 1.0 % for both matrine andsecnidazole.Conclusion: The developed HPLC method was validated according to International Conference on Harmonisation (ICH) guidelines and proved to be suitable for the simultaneous determination of matrine and secnidazole in suppositories.Keywords: Matrine, Secnidazole, Suppository, HPLC, Assay

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42

Liu, Xue Ting, Yan Lei Zhao, and Hou Sheng Zhang. "The Property of Kippenhahn Curves in Engineering Applications." Advanced Materials Research 108-111 (May 2010): 663–69. http://dx.doi.org/10.4028/www.scientific.net/amr.108-111.663.

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In this paper, let and be deoted reducible companion matrices, we study the property of the Kippenhahn curve and of the numerical rang being an elliptic disc by making use of matrices Kronecker sum , Kronecker product and Hadamard product and the Kippenhahn curve continually.

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43

Иванов, А. А., В. В. Чалдышев, Е. Е. Заварин, А. В. Сахаров, В. В. Лундин, and А. Ф. Цацульников. "Резонансное отражение света оптической решеткой экситонов, сформированной 100 квантовыми ямами InGaN." Физика и техника полупроводников 55, no. 9 (2021): 733. http://dx.doi.org/10.21883/ftp.2021.09.51286.13.

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Optical properties of a structure with a periodic system of 100 InGaN quantum wells (QWs) separated by non-tunneling GaN barriers have been investigated at room temperature. The structure periodicity corresponded to the Bragg diffraction condition at the frequency of the QW excitons. Numerical modeling using transfer matrices gave a quantitatively accurate fit of the experimental results. The model included the resonance response of A, B, and C excitons in QWs and an optical absorption tail in the barriers and buffer layer. We have determined the radiative and non-radiative broadening of the excitons in the InGaN QWs.

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44

Wang, Xiuping, Zhizhong Xue, Xuelin Lu, Yahui Liu, Guangming Liu, and Zhe Wu. "Salt leaching of heavy coastal saline silty soil by controlling the soil matric potential." Soil and Water Research 14, No. 3 (May 27, 2019): 132–37. http://dx.doi.org/10.17221/106/2018-swr.

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Techniques of drip irrigation are broadly applied for the reclamation of saline-alkali lands, during which effective management of water use to accelerate salt leaching is essential for crop production. In 2017, a field experiment with five treatments of soil matric potential (SMP) levels of −5, −10, −15, −20, and −25 kPa was conducted in heavy saline silty soil land in Bohai Bay, China to study the effects of drip irrigation on salt leaching. The results showed that salt leaching was enhanced with increasing SMP, particularly under an SMP of −5 kPa within a 30 cm soil profile depth and 15 cm distance from the dripper, and the average electrical conductivity of saturated paste extracts (ECe) decreased from 13.8 to 1.52 dS/m. Water consumption increased with increasing SMP, but the yield of oil sunflower did not differ significantly between SMPs of –5 and –10 kPa. These findings indicated that a relatively high crop yield of oil sunflower and effective salt leaching can be achieved if the SMP can be controlled at –10 kPa in heavy saline silty soil.

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45

Yoneda, Gen, and Hisa-aki Shinkai. "Diagonalizability of constraint propagation matrices." Classical and Quantum Gravity 20, no. 4 (January 22, 2003): L31—L36. http://dx.doi.org/10.1088/0264-9381/20/4/102.

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46

Grujić-Letić, Nevena, Branislava Rakić, Emilia Šefer, Maja Milanović, Maja Nikšić, Ivana Vujić, and Nataša Milić. "Quantitative determination of caffeine in different matrices." Macedonian Pharmaceutical Bulletin 62, no. 1 (2016): 77–84. http://dx.doi.org/10.33320/maced.pharm.bull.2016.62.01.007.

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Caffeine is odorless, bitter taste substance which can be naturally found in coffee, cocoa, tea leaves, and is intentionally added in food and pharmaceutical products. It can also be found in surface water in small concentrations where is often used as an excellent indicator of human waste. The aim of the work is determination of caffeine content in food, beverages, analgesics and surface water using solidphase extraction followed by high-performance liquid chromatography (HPLC). Caffeine content was determined in 12 commercial tea and coffee products, non-alcoholic energy drinks and food, 5 combined preparations of analgesics and the Danube samples collected from 7 representative locations. The results showed that caffeine content in food ranged 5,6-158 mg/100 g, tea samples 24,71-30,81 mg/100 ml, coffee samples 1328-3594 mg/100 g, energy drinks 9,69-30,79 mg/100 ml and in the Danube samples 15,91-306,12 ng/l. Caffeine content in combined commercial formulations of non-narcotic analgesics of all brands did meet specifications. The data suggested that the proposed HPLC method can be used for routine determination and control of caffeine content in different matrices.

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47

Zhao, Wen Ling. "The Property of Kippenhahn Curves of Kronecker Sum and Applications." Advanced Materials Research 108-111 (May 2010): 670–75. http://dx.doi.org/10.4028/www.scientific.net/amr.108-111.670.

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In many physical applications, we must solve a system of linear equations such as . The Kronecker sum can get a convenient representation for linear equations . In this paper, let and be denoted reducible companion matrices. We study the property of the Kippenhahn curve and of the numerical rang being an elliptic disc by making use of matrices Kronecker sum and the Kippenhahn curve continually.

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48

Beck-Broichsitter, Steffen, Horst Gerke, and Rainer Horn. "Shrinkage Characteristics of Boulder Marl as Sustainable Mineral Liner Material for Landfill Capping Systems." Sustainability 10, no. 11 (November 2, 2018): 4025. http://dx.doi.org/10.3390/su10114025.

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The soil shrinkage behavior of mineral substrates needs to be considered for engineering long-term durable mineral liners of landfill capping systems. For this purpose, a novel three-dimensional laser scanning device was coupled with (a) a mathematical-empirical model and (b) in-situ tensiometer measurements as a combined approach to simultaneously determine the shrinkage behavior of a boulder marl, installed as top and bottom liner material at the Rastorf landfill (Northern Germany). The shrinkage behavior, intensity, and geometry were determined during a drying experiment with undisturbed soil cores (100 cm3) from two soil pits; the actual in-situ shrinkage was also determined in 0.2, 0.5, 0.8, and 1.0 m depth by pressure transducer tensiometer measurements during a four-year period. The volume shrinkage index was used to describe the pore size dependent shrinkage tendency and it was classified as low (4.9%) for the bottom liner. The in-situ matric potentials in the bottom liner ranged between −100 and −150 hPa, even during drier periods, thus, the previously highest observed drying range (pre-shrinkage stress) with values below −500 hPa and −1000 hPa was not exceeded. Therefore, the hydraulic stability of the bottom liner was given.

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AL-Emami, Omar, Gabriela M Medero, Fernando A M Marinho, and Melis Sutman. "Analysis of the suction evolution during direct shear test in a silty sand soil." E3S Web of Conferences 195 (2020): 03031. http://dx.doi.org/10.1051/e3sconf/202019503031.

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Shear strength of soils is one of the essential parameters for analysing and solving divers geotechnical problems (e.g. the bearing capacity of shallow footings pile foundations, slope stability and earth embankments). In this study, a series of conventional large-scale (300 X 300 mm) direct shear tests were carried out on saturated and constant water content silty sand specimens at ei = 0.6 and 1.0 tested under applied vertical stresses of 100, 200, or 400 kPa to investigate the influence of matric suction on the shear strength characteristics of the tested material. A loading steel cap was modified to allow the direct measurements of the matric suction using two commercial available Equitensiometer suction probes (EQ3). The experimental program indicated that, for both studied void ratios, the obtained shear strength of specimens under constant water content is found to be distinctly greater than those obtained from saturated samples. The results showed that the samples compacted at ei = 1.0 exhibited collapse behaviour during saturation stage, whereas same samples did not show any volume change during stabilisation stage when tested under constant water content condition. The study results also showed that the matric suction reduction during consolidation stage depends on initial void ratio of the tested samples as well as the level of applied vertical stress. Moreover, the matric suction evolution during shearing process of both studied void ratios specimens decreased with increasing the level of applied vertical stress.

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50

Ma, Zhi-Jie, Qi Li, Jia-Bo Wang, Yan-Ling Zhao, Yan-Wei Zhong, Yun-Feng Bai, Rui-Lin Wang, et al. "Combining Oxymatrine or Matrine with Lamivudine Increased Its Antireplication Effect against the Hepatitis B VirusIn Vitro." Evidence-Based Complementary and Alternative Medicine 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/186573.

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Some recent clinical reports have shown that the combination of oxymatrine, a phyto-derived drug, with lamivudine (3TC) could improve its curative effect against hepatitis B virus (HBV) infection. However, the experimental data in support of this combination strategy are lacking. In this study, we investigated the anti-HBV activity of the combination of 3TC and either oxymatrine or matrine on HepG2 2.2.15in vitro. The activities of the combination and the solo compound, each in different concentrations, were compared on the 3rd, 6th, and 9th experimental days. The cytotoxicity results showed that the nontoxic concentrations of both oxymatrine and matrine to HepG2 2.2.15 cells were 800 μg/mL. We found that the single use of oxymatrine below 100 μg/ml, matrine below 200 μg/ml, and 3TC below 30 μg/ml showed weak inhibitory effects on the secretion of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and HBV-DNA in culture media; the combination of 3TC (30 μg/ml) with oxymatrine (100 μg/ml) or matrine (100 μg/ml) showed significant inhibitory effects that were higher than or equivalent to the single use of 3TC at 100 μg/ml. The results provide a new impetus to develop novel, multicomponent anti-HBV drugs through the combination of natural products with nucleoside analogs to enhance their activity.

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