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1
Murata, Yoshinori, Shingo Sakurai, Efendi Mabruri, Toshiyuki Koyama, and Masahiko Morinaga. "Cross Interdiffusion Coefficients in Nickel- and Iron-Based Ternary Alloys." Defect and Diffusion Forum 273-276 (February 2008): 419–24. http://dx.doi.org/10.4028/www.scientific.net/ddf.273-276.419.
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It is known that two main interdiffusion coefficients, ık Dii and ık Djj , as well as two cross interdiffusion coefficients, ık Dij and ık Dji , are necessary for understanding the atomic diffusion for ternary system. Here, k is the host element of ternary system, and i and j are solute elements. These four interdiffusion coefficients are obtained from a series of experiments using two kinds of ternary diffusion couples. In general, it is believed that ık Dij and ık Dji indicate the same sign to each other, but there are a lot of experimental data showing that ık Dij and ık Dji indicate opposite sign [1]. In such a case, the physical meaning of the cross interdiffusion coefficient has not always been understood thoroughly. The purposes of this study are to measure the interdiffusion coefficients by a series of experiments and to elucidate the physical meaning of the two cross interdiffusion coefficients on the basis of the consideration about the relationship between the thermodynamic functions and the cross interdiffusion coefficients. It is concluded that ık Dij exhibits the opposite sign to ık Dji without contradicting the Onsarger’s reciprocity theorem when the ( 2 2 ) c j ∂ G ∂c shows the opposite sign to ( 2 2 ) c i ∂ G ∂c . Here, c G is Gibbs free energy of the ternary system.
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Rauschenbach, Thomas, Svendy Wittmann, and Felix Berth. "Das Deutsche Jugendinstitut (DJI)." Erziehungswissenschaft 30, no. 59 (2-2019) (December 13, 2019): 55–61. http://dx.doi.org/10.3224/ezw.v30i2.07.
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Huang, Chia-Hsing, and Liang-Chun Ho. "The relationship between the bio-energy concept stocks in Taiwan and the international stock markets." Corporate Ownership and Control 5, no. 4 (2008): 437–43. http://dx.doi.org/10.22495/cocv5i4c5p3.
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This research explores the relationship among the bio-energy company stock index in Taiwan, TAIEX, DJI, Nikkei 225 and SSE composite index for a period from January 1, 2005 to March 11, 2008. Test results indicate two things are noteworthy: 1. Granger causality tests show that the interaction between the bio-energy company stock index in Taiwan and TAIEX is one-way only; however, that between the bio-energy company stock index in Taiwan and DJI is two-way. 2. According to the results of variance decompositions, though TAIEX has the highest explanation power; nevertheless, the explanation strength tends to decrease. On the contrary, DJI and Nikkei 225 manifest constantly increasing strength in explanation. Accordingly, the influence of DJI upon the bio-energy company stock index in Taiwan keeps rising and can’t be ignored.
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Van den Hurk, Arie, and Annelies Jorna. "De DJI en de wetenschap." PROCES 95, no. 5 (October 2016): 41–56. http://dx.doi.org/10.5553/proces/016500762016095005006.
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Salma, N. M., and Khairuddin Osman. "Modelling and PID control system integration for quadcopter DJI F450 attitude stabilization." Indonesian Journal of Electrical Engineering and Computer Science 19, no. 3 (September 1, 2020): 1235. http://dx.doi.org/10.11591/ijeecs.v19.i3.pp1235-1244.
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<p><span style="font-family: Times New Roman;">In this paper we focus on the overall overview of the mathematical modelling of the DJI F450 UAV quadcopter, the hardware and software system integration based on PID control system for the attitude feedback. The parameter specification of the DJI F450 is fed into the mathematical model and implement a basic PID for the system. Future research using the DJI F450 model can benefit from this observation by implementing the modelling and tune in their own variable that varies, such as the overall of their weight. The data of PID control system simulation using the quadcopter frame model type DJI F450 parameter. The mathematical model for the quadcopter modelled DJI F450 is developed using Newton-Euler method. Altitude data for the control system is obtain from the analysis data of the Simulink simulation. The simulation is done using the Simulink toolbox inside the MATLAB software. From this paper, we can more understand the step involves in making a full control system of a quadcopter. The mathematical model for other type of quadcopter model can be implemented using the steps with their own parameter and achieve fast development.</span></p>
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Lisa Kustina, Samsul Anwar, and Imas Mawar. "PENGARUH BURSA SAHAM GLOBAL TERHADAP INDEKS HARGA SAHAM GABUNGAN DI BURSA EFEK INDONESIA." Jurnal Investasi 4, no. 1 (April 9, 2018): 1–10. http://dx.doi.org/10.31943/investasi.v4i1.32.
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Tujuan Penelitian ini adalah untuk mengetahui pengaruh bursa saham global terhadap indeks harga saham gabungan di Bursa Efek Indonesia. Bursa saham global yang digunakan dalam penelitian ini adalah Dow Jones Index (DJI), Korea Stock Price Composite Index (KOSPI), Tokyo Stock Exchange (Nikkei heikin kabuki / Nikkei 225), dan Australian Securities Exchange (ASX). Sampel yang diteliti dalam penelitian ini adalah periode 2015 hingga 2017. Penelitian ini menggunakan regresi linear berganda untuk mengolah data penelitian. Hasil Penelitian ini menunjukkan bahwa Dow Jones Index (DJI), Korea Stock Price Composite Index (KOSPI), Tokyo Stock Exchange (Nikkei heikin kabuki / Nikkei 225), dan Australian Securities Exchange (ASX) secara parsial berpengaruh terhadap Indek Harga Saham Gabungan diIndonesia. Dow Jones Index (DJI), Korea Stock Price Composite Index (KOSPI), dan Australian Securities Exchange (ASX) berpengaruh signifikan pada tingkat signifikansi 0.000 sedangkan Tokyo Stock Exchange (Nikkei 225) pada tingkat signifikansi 0.001.
The purpose of this study was to determine the effect of global stock exchanges on the composite stock price index on the Indonesia Stock Exchange. The global stock exchanges used in this study are the Dow Jones Index (DJI), the Korea Stock Price Composite Index (KOSPI), the Tokyo Stock Exchange (Nikkei Heikin Kabuki / Nikkei 225), and the Australian Securities Exchange (ASX). The sample examined in this study is the period 2015 to 2017. This study uses multiple linear regression to process research data. The results of this study indicate that the Dow Jones Index (DJI), the Korea Stock Price Composite Index (KOSPI), the Tokyo Stock Exchange (Nikkei Heikin Kabuki / Nikkei 225), and the Australian Securities Exchange (ASX) partially affect the Composite Stock Price Index in Indonesia. The Dow Jones Index (DJI), the Korea Stock Price Composite Index (KOSPI), and the Australian Securities Exchange (ASX) have a significant effect on the significance level of 0,000 while the Tokyo Stock Exchange (Nikkei 225) is at a significance level of 0.001.
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Taddia, Yuri, Francesco Stecchi, and Alberto Pellegrinelli. "Coastal Mapping Using DJI Phantom 4 RTK in Post-Processing Kinematic Mode." Drones 4, no. 2 (March 30, 2020): 9. http://dx.doi.org/10.3390/drones4020009.
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Topographic and geomorphological surveys of coastal areas usually require the aerial mapping of long and narrow sections of littoral. The georeferencing of photogrammetric models is generally based on the signalization and survey of Ground Control Points (GCPs), which are very time-consuming tasks. Direct georeferencing with high camera location accuracy due to on-board multi-frequency GNSS receivers can limit the need for GCPs. Recently, DJI has made available the Phantom 4 Real-Time Kinematic (RTK) (DJI-P4RTK), which combines the versatility and the ease of use of previous DJI Phantom models with the advantages of a multi-frequency on-board GNSS receiver. In this paper, we investigated the accuracy of both photogrammetric models and Digital Terrain Models (DTMs) generated in Agisoft Metashape from two different image datasets (nadiral and oblique) acquired by a DJI-P4RTK. Camera locations were computed with the Post-Processing Kinematic (PPK) of the Receiver Independent Exchange Format (RINEX) file recorded by the aircraft during flight missions. A Continuously Operating Reference Station (CORS) located at a 15 km distance from the site was used for this task. The results highlighted that the oblique dataset produced very similar results, with GCPs (3D RMSE = 0.025 m) and without (3D RMSE = 0.028 m), while the nadiral dataset was affected more by the position and number of the GCPs (3D RMSE from 0.034 to 0.075 m). The introduction of a few oblique images into the nadiral dataset without any GCP improved the vertical accuracy of the model (Up RMSE from 0.052 to 0.025 m) and can represent a solution to speed up the image acquisition of nadiral datasets for PPK with the DJI-P4RTK and no GCPs. Moreover, the results of this research are compared to those obtained in RTK mode for the same datasets. The novelty of this research is the combination of a multitude of aspects regarding the DJI Phantom 4 RTK aircraft and the subsequent data processing strategies for assessing the quality of photogrammetric models, DTMs, and cross-section profiles.
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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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Stanković, Miloš, Mohammad Meraj Mirza, and Umit Karabiyik. "UAV Forensics: DJI Mini 2 Case Study." Drones 5, no. 2 (June 1, 2021): 49. http://dx.doi.org/10.3390/drones5020049.
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Rapid technology advancements, especially in the past decade, have allowed off-the-shelf unmanned aerial vehicles (UAVs) that weigh less than 250 g to become available for recreational use by the general population. Many well-known manufacturers (e.g., DJI) are now focusing on this segment of UAVs, and the new DJI Mini 2 drone is one of many that falls under this category, which enables easy access to be purchased and used without any Part 107 certification and Remote ID registration. The versatility of drones and drone models is appealing for customers, but they pose many challenges to forensic tools and digital forensics investigators due to numerous hardware and software variations. In addition, different devices can be associated and used for controlling these drones (e.g., Android and iOS smartphones). Moreover, according to the Federal Aviation Administration (FAA), the adoption of Remote ID is not going to be required for people without the 107 certifications for this segment at least until 2023, which creates finding personally identifiable information a necessity in these types of investigations. In this research, we conducted a comprehensive investigation of DJI Mini 2 and its data stored across multiple devices (e.g., SD cards and mobile devices) that are associated with the drone. The aim of this paper is to (1) create several criminal-like scenarios, (2) acquire and analyze the created scenarios using leading forensics software (e.g., Cellebrite and Magnet Axiom) that are commonly used by law enforcement agencies, (3) and present findings associated with potential criminal activities.
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Nur Anisa, Medina, Rokhmatuloh, and Revi Hernina. "UAV application to estimate oil palm trees health using Visible Atmospherically Resistant Index (VARI) (Case study of Cikabayan Research Farm, Bogor City)." E3S Web of Conferences 211 (2020): 05001. http://dx.doi.org/10.1051/e3sconf/202021105001.
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This article describes the making of an oil palm tree health map using aerial photos extracted from UAV DJI Phantom 4. A DJI Phantom 4 was flown at 100 meters height at the Cikabayan Research Farm, Bogor City. Raw aerial photos from DJI Phantom 4 were processed using Agisoft Photoscan software to generate dense point clouds. These points were computed to produce a digital surface model (DSM) and orthophotos with a spatial resolution of 2.73 cm/pixel. Red, green, and blue bands of the photos were computed to provide the Visible Atmospherically Resistant Index (VARI). Also, orthophotos containing oil palm trees were digitized to create points in vector form. VARI pixel values were added to each point and classified into four classes: Needs Inspection, Declining Health, Moderately health, and Healthy. Resulted oil palm tree health map reveals that most of the oil palm trees in the study location are classified as Declining Health and Needs Inspection. Profitably, plantation workers can directly inspect oil palm trees whose health are declining, based on information derived from oil palm tree health map. The information that comes from this study will significantly save time and effort in monitoring oil palm trees’ healthiness.
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Kelly Sze Hiu Chin, Stanley Yau Kit Ying, Yifan Zhang, and Alex Chun Yin Siu. "Da Jiang Innovation, DJI: The Future of Possible." Academy of Asian Business Review 3, no. 2 (December 2017): 83–109. http://dx.doi.org/10.26816/aabr.3.2.201712.83.
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Silva, M. R. S., R. A. Eger, Y. A. Z. Rosenfeldt, and C. Loch. "TESTING DJI PHANTOM 4 PRO FOR URBAN GEOREFERENCING." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-1 (September 26, 2018): 407–11. http://dx.doi.org/10.5194/isprs-archives-xlii-1-407-2018.
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<p><strong>Abstract.</strong> The urban environment is dynamic and is constantly changing. In Brazil, it has been recently published a decree for urban land regulation for the cadastre &ndash; Decree No 9.310 of 2018 15 of March which fixes 8,0 centimeters as the maximum spherical positional error for vertex of an urban property stock being georeferenced by Global Navigation Satellite System &ndash; GNSS equipment or aerial orthophotograph. Nowadays it has been noticed a growing use of Unmanned Aircraft Vehicle System &ndash; UAVS for remote sensing. This work aims to test if the accuracy of orthophoto-mosaic from a small UAVS mapping data of an urban area for a parcel scale georeferencing is answering the new decree of urban land regulation for the cadastre. It is intended to check the number of Ground Control Points (GCPs) to reach the best quality in terms of geometric resolution according to the necessity of positional quality for the urban parcel georeferenced for the cadastre. As a final consideration, the results implied that mapping a small surveying area with small UAVS is worth, being a potential tool for georeferencing city blocks, and using 20 pairs of GCPs is enough to reach the quality of positional geometry adequate to the Brazilian legislation.</p>
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Jae-Do, SONG. "Drone Market Expansion and Success Factors of DJI." Korean Journal of Converging Humanities 6, no. 4 (November 30, 2018): 55–85. http://dx.doi.org/10.14729/converging.k.2018.6.4.55.
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Forte, Janina Dos Santos. "Lang dji Pota-Iela: a Língua dos Pota." Revista Brasileira de Línguas Indígenas 2, no. 1 (June 9, 2020): 29. http://dx.doi.org/10.18468/rbli.2019v2n1.p29-44.
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O presente trabalho trata de conhecimentos e práticas culturais indígenas do povo Karipuna que vive na Terra Indígena do Uaçá, no Estado do Amapá. O pota é uma prática cultural que envolve a cura e a causa de algumas doenças muitas vezes provocadas por seres sobrenaturais. O pota é reza, canto utilizado para proporcionar alívio ou até mesmo a cura dessas doenças, ele é realizado por pessoas especialistas, não necessariamente um pajé, podendo ser cantado, assobiado ou murmurado, muitas vezes, assoprado. Não se sabe ao certo a origem dessa prática, ela é muito utilizada por vários povos indígenas da região do Uaçá, por isso, o pota apresenta em sua constituição diferentes palavras de diferentes línguas da família Karib e Aruák além da língua Kheuol Karipuna. Neste trabalho, o meu objetivo é descrever as estruturas do pota identificando palavras das diferentes línguas utilizadas nas composições das rezas/canto utilizando meus conhecimentos empíricos e linguísticos. Além de descrever as estruturas do pota, registrei, através de áudio, 33 pota. Como pertencente ao povo Karipuna, sei da importância de resguardar esses saberes que fazem parte da nossa identidade.
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Przybilla, H. J., M. Bäumker, T. Luhmann, H. Hastedt, and M. Eilers. "INTERACTION BETWEEN DIRECT GEOREFERENCING, CONTROL POINT CONFIGURATION AND CAMERA SELF-CALIBRATION FOR RTK-BASED UAV PHOTOGRAMMETRY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B1-2020 (August 6, 2020): 485–92. http://dx.doi.org/10.5194/isprs-archives-xliii-b1-2020-485-2020.
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Abstract. Unmanned Aerial Vehicles (UAV) are enjoying increasing popularity in the photogrammetric community. The Chinese supplier DJI is the market leader with about 70% of the global consumer UAV market. The Phantom model has been available for more than 10 years and its current version "RTK" is equipped with a 2-frequency GNSS receiver, as a basis for direct georeferencing of image flights, using RTK or PPK technologies.In the context of the paper, different case studies are investigated, which allow statements on the geometric accuracy of UAV image flights as well as on the self-calibration of the camera systems.In the first example, four DJI Phantom 4 RTK systems are examined, which were flown in a cross flight pattern configuration on the area of the UAV test field "Zeche Zollern" in Dortmund, Germany. The second example analyses the results of an open moorland area where the establishment of GCPs is extremely difficult and expensive, hence direct georeferencing offers a promising way to evaluate deformations, soil movements or mass calculations. In this example a DJI Matrice 210 v2 RTK drone has been used and the results of two different software packages (Agisoft Metashape and RealityCapture) are analysed. The third example presents a reference building that has been established by the Lower Saxony administration for geoinformation in order to evaluate UAV photogrammetry for cadastral purposes. Here again a DJI Phantom 4 RTK has been tested in a variety of flight configurations and a large number of high precision ground control and check points.The case studies show that the RTK option leads to sufficient results if at least 1 GCP is introduced. Flights without any GCPs lead to a significant height error in the order of up to 30 GSD.
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Перлін, C. І., and С. М. Лозова. "ДЕЯКІ НАПРЯМИ ВИКОРИСТАННЯ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ У СЛІДЧІЙ ТА ЕКСПЕРТНІЙ ПРАКТИЦІ." Науково-теоретичний журнал «Вісник Луганського державного університету внутрішніх справ імені Е.О. Дідоренка» 1, no. 89 (March 6, 2020): 269–79. http://dx.doi.org/10.33766/2524-0323.89.269-279.
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У статті розглянуто сучасний стан використання безпілотних літальних апаратів у криміналістичної діяльності. Проаналізовано нові засоби і методи, які можуть бути вико-ристані в криміналістичній діяльності, пов'язаній із фіксацією слідчих (розшукових) дій, а також у процесі проведення та оформлення результатів експертних досліджень на прикладі квадрокоптера DJI Mavic 2 Pro, який використовується в практичній діяльності Харківського науково-дослідного експертно-криміналістичного центру Міністерства внутрішніх справ України. Надано визначення поняття «безпілотний літальний апарат». Запропоновано кри-міналістичну класифікацію безпілотних літальних апаратів, що заснована на загальних підходах до систематизації техніко-криміналістичних засобів. Розглянуто основні технічні ха-рактеристики квадрокоптера DJI Mavic 2 Pro і його корисні функції. Сформульовано пропо-зиції щодо впровадження в слідчу та експертну практику безпілотних літальних апаратів.
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Gülci, S., M. Akgül, A. E. Akay, and İ. Taş. "USING READY-TO-USE DRONE IMAGES in FORESTRY ACTIVITIES: CASE STUDY OF ÇINARPINAR in KAHRAMANMARAS, TURKEY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W6 (November 13, 2017): 51–53. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w6-51-2017.
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This short paper aims to present pros and cons of current usage of ready-to-use drone images in the field of forestry also considering flight planning and photogrammetric processes. The capabilities of DJI Phantom 4, which is the low cost drone producing by Dji company, was evaluated through sample flights in Cinarpinar Forest Enterprise Chief in Kahramanmaras in Turkey. In addition, the photogrammetric workflow of obtained images and automated flight were presented with respect to capabilities of available software. The flight plans were created by using Pix4DCapture software with android based cell phone. The results indicated that high-resolution imagery obtained by drone can provide significant data for assessment of forest resources, forest roads, and stream channels.
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Rogers, Stephanie R., Ian Manning, and William Livingstone. "Comparing the Spatial Accuracy of Digital Surface Models from Four Unoccupied Aerial Systems: Photogrammetry Versus LiDAR." Remote Sensing 12, no. 17 (August 29, 2020): 2806. http://dx.doi.org/10.3390/rs12172806.
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The technological growth and accessibility of Unoccupied Aerial Systems (UAS) have revolutionized the way geographic data are collected. Digital Surface Models (DSMs) are an integral component of geospatial analyses and are now easily produced at a high resolution from UAS images and photogrammetric software. Systematic testing is required to understand the strengths and weaknesses of DSMs produced from various UAS. Thus, in this study, we used photogrammetry to create DSMs using four UAS (DJI Inspire 1, DJI Phantom 4 Pro, DJI Mavic Pro, and DJI Matrice 210) to test the overall accuracy of DSM outputs across a mixed land cover study area. The accuracy and spatial variability of these DSMs were determined by comparing them to (1) 12 high-precision GPS targets (checkpoints) in the field, and (2) a DSM created from Light Detection and Ranging (LiDAR) (Velodyne VLP-16 Puck Lite) on a fifth UAS, a DJI Matrice 600 Pro. Data were collected on July 20, 2018 over a site with mixed land cover near Middleton, NS, Canada. The study site comprised an area of eight hectares (~20 acres) with land cover types including forest, vines, dirt road, bare soil, long grass, and mowed grass. The LiDAR point cloud was used to create a 0.10 m DSM which had an overall Root Mean Square Error (RMSE) accuracy of ±0.04 m compared to 12 checkpoints spread throughout the study area. UAS were flown three times each and DSMs were created with the use of Ground Control Points (GCPs), also at 0.10 m resolution. The overall RMSE values of UAS DSMs ranged from ±0.03 to ±0.06 m compared to 12 checkpoints. Next, DSMs of Difference (DoDs) compared UAS DSMs to the LiDAR DSM, with results ranging from ±1.97 m to ±2.09 m overall. Upon further investigation over respective land covers, high discrepancies occurred over vegetated terrain and in areas outside the extent of GCPs. This indicated LiDAR’s superiority in mapping complex vegetation surfaces and stressed the importance of a complete GCP network spanning the entirety of the study area. While UAS DSMs and LiDAR DSM were of comparable high quality when evaluated based on checkpoints, further examination of the DoDs exposed critical discrepancies across the study site, namely in vegetated areas. Each of the four test UAS performed consistently well, with P4P as the clear front runner in overall ranking.
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Laporte-Fauret, Quentin, Vincent Marieu, Bruno Castelle, Richard Michalet, Stéphane Bujan, and David Rosebery. "Low-Cost UAV for High-Resolution and Large-Scale Coastal Dune Change Monitoring Using Photogrammetry." Journal of Marine Science and Engineering 7, no. 3 (March 7, 2019): 63. http://dx.doi.org/10.3390/jmse7030063.
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In this paper, coastal dune data are collected at Truc Vert, SW France, using photogrammetry via Unmanned Aerial Vehicles (UAVs). A low-cost GoPro-equipped DJI Phantom 2 quadcopter and a 20 MPix camera-equipped DJI Phantom 4 Pro quadcopter UAVs were used to remotely sense the coastal dune morphology over large spatial scales (4 km alongshore, i.e., approximately 1 km2 of beach-dune system), within a short time (less than 2 h of flight). The primary objective of this paper is to propose a low-cost and replicable approach which, combined with simple and efficient permanent Ground Control Point (GCP) set-up, can be applied to routinely survey upper beach and coastal dune morphological changes at high frequency (after each storm) and high resolution (0.1 m). Results show that a high-resolution and accurate Digital Surface Model (DSM) can be inferred with both UAVs if enough permanent GCPs are implemented. The more recent DJI Phantom 4 gives substantially more accurate DSM with a root-mean-square vertical error and bias of 0.05 m and −0.03 m, respectively, while the DSM inferred from the DJI Phantom 2 still largely meets the standard for coastal monitoring. The automatic flight plan procedure allows replicable surveys to address large-scale morphological evolution at high temporal resolution (e.g., weeks, months), providing unprecedented insight into the coastal dune evolution driven by marine and aeolian processes. The detailed morphological evolution of a 4-km section of beach-dune system is analyzed over a 6-month winter period, showing highly alongshore variable beach and incipient foredune wave-driven erosion, together with wind-driven inland migration of the established foredune by a few meters, and alongshore-variable sand deposition on the grey dune. In a context of widespread erosion, this photogrammetry approach via low-cost flexible and lightweight UAVs is well adapted for coastal research groups and coastal dune management stakeholders, including in developing countries where data are lacking.
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Hu, Tianyu, Xiliang Sun, Yanjun Su, Hongcan Guan, Qianhui Sun, Maggi Kelly, and Qinghua Guo. "Development and Performance Evaluation of a Very Low-Cost UAV-Lidar System for Forestry Applications." Remote Sensing 13, no. 1 (December 28, 2020): 77. http://dx.doi.org/10.3390/rs13010077.
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Accurate and repeated forest inventory data are critical to understand forest ecosystem processes and manage forest resources. In recent years, unmanned aerial vehicle (UAV)-borne light detection and ranging (lidar) systems have demonstrated effectiveness at deriving forest inventory attributes. However, their high cost has largely prevented them from being used in large-scale forest applications. Here, we developed a very low-cost UAV lidar system that integrates a recently emerged DJI Livox MID40 laser scanner (~$600 USD) and evaluated its capability in estimating both individual tree-level (i.e., tree height) and plot-level forest inventory attributes (i.e., canopy cover, gap fraction, and leaf area index (LAI)). Moreover, a comprehensive comparison was conducted between the developed DJI Livox system and four other UAV lidar systems equipped with high-end laser scanners (i.e., RIEGL VUX-1 UAV, RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE). Using these instruments, we surveyed a coniferous forest site and a broadleaved forest site, with tree densities ranging from 500 trees/ha to 3000 trees/ha, with 52 UAV flights at different flying height and speed combinations. The developed DJI Livox MID40 system effectively captured the upper canopy structure and terrain surface information at both forest sites. The estimated individual tree height was highly correlated with field measurements (coniferous site: R2 = 0.96, root mean squared error/RMSE = 0.59 m; broadleaved site: R2 = 0.70, RMSE = 1.63 m). The plot-level estimates of canopy cover, gap fraction, and LAI corresponded well with those derived from the high-end RIEGL VUX-1 UAV system but tended to have systematic biases in areas with medium to high canopy densities. Overall, the DJI Livox MID40 system performed comparably to the RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE systems in the coniferous site and to the Velodyne Puck LITE system in the broadleaved forest. Despite its apparent weaknesses of limited sensitivity to low-intensity returns and narrow field of view, we believe that the very low-cost system developed by this study can largely broaden the potential use of UAV lidar in forest inventory applications. This study also provides guidance for the selection of the appropriate UAV lidar system and flight specifications for forest research and management.
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Jullyantari, Ni Luh Putu, I. Made Anom Sutrisna Wijaya, and I. Putu Gede Budisanjaya. "Pendugaan Intensitas Serangan Penyakit BLB (Bacterial Leaf Blight) pada Tanaman Padi menggunakan Pendekatan Citra Termal." Jurnal BETA (Biosistem dan Teknik Pertanian) 9, no. 1 (April 30, 2021): 86. http://dx.doi.org/10.24843/jbeta.2021.v09.i01.p09.
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Penyakit BLB merupakan salah satu penyakit yang berbahaya bagi tanaman padi. Penyakit ini biasanya menyerang di setiap fase pertumbuhan. Perhitungan intensitas serangan penyakit BLB masih dilakukan secara manual. Pengembangan teknologi dalam pendugaan intensitas serangan penyakit BLB sangat diperlukan. Penelitian ini bertujuan untuk membangun persamaan pendugaan intensitas serangan penyakit BLB menggunakan pendekatan citra termal. Penelitian ini menggunakan Drone DJI Inspire 1 dengan kamera termal DJI Zenmuse XT. Pengolahan data menggunakan software Agisoft Photoscan, Arcgis 10.3 dan Microsoft Excel. Dari hasil analisis citra termal diperoleh bahwa persamaan pendugaan intensitas serangan adalah y = 4.9533x-144.42 dan akurasi pendugaannya tinggi yaitu 90,45% dengan nilai eror 8,43%. Suhu kanopi dapat diklasifikasi menjadi empat sesuai dengan intensitas serangan yaitu 29,83-31,84oC untuk intensitas serangan ringan, 31,85-34,39oC untuk intensitas serangan sedang, 34,40-43,52oC untuk intensitas serangan berat dan 43,53-48,09oC untuk intensitas serangan puso. Berdasarkan hasil dari penelitian yang telah dilakukan dapat disimpulkan bahwa pendekatan citra termal dapat digunakan untuk menduga intensitas serangan penyakit BLB pada tanaman padi.
Bacterial Leaf Blight (BLB) is a dangerous disease for rice plants. This disease can attack in every phase of growth. Calculation of BLB disease attack intensity is currently still done manually. Technology development in estimating the intensity of BLB disease is very necessary. This study aims to establish the equation for estimating BLB disease intensity using a thermal image approach. Drone DJI Inspire 1 with a thermal camera DJI Zenmuse XT was used in this research. Processing data using software Agisoft Photoscan, Arcgis 10.3 and Microsoft Excel. From the results of the thermal image analysis, it was found that the equation for estimating attack intensity is y = 4.9533x-144.42 and estimation accuracy is high at 90,45% with an error value of 8,43%. Temperature of the canopy can be classified into four according to the intensity of the attack, namely 29,83-31,84oC for mild attack intensity, 31,85-34,39oC for moderate attack intensity, 34,40-43,52oC for intensity of severe attacks and 43,53-48,09oC for intensity of puso attacks. From these results it can be concluded that the thermal image approach can be used to estimate BLB disease attacks on rice plants.
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Mutohharo, Naji Hatul, and Putri Nurhayati. "FLUKTUASI SAHAM SYARIAH DI INDONESIA SAAT PANDEMI COVID-19 AKIBAT PERUBAHAN VARIABEL MAKROEKONOMI: ANALISIS PADA SUB SEKTOR HOTEL, RESTAURANT DAN PARIWISATA." Jurnal Ekonomi Syariah Teori dan Terapan 8, no. 4 (July 28, 2021): 384. http://dx.doi.org/10.20473/vol8iss20214pp384-400.
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ABSTRAKPandemi COVID-19 merebak dengan cepat keseluruh negara di dunia menimbulkan banyak dampak termasuk dalam bidang perekonomian. Adanya kebijakan-kebijakan khusus untuk mencegah penyebaran virus, seperti pembatasan mobilisasi dan kegiatan public memberikan dampak yang cukup masif, termasuk pada bidang pariwisata. Penelitian ini bertujuan untuk melihat pengaruh beberapa variabel makro, berupa nilai tukar, IHSG, Dow Jones Index (DJI), Dow Jones Islamic Market Index (DJIMI), dan harga minyak dunia terhadap fluktuasi harga saham perusahaan sub sektor hotel, restoran, dan pariwisata yang terdaftar dalam Indeks Saham Syariah Indonesia. Menggunakan metode Partial Least Square (PLS), menunjukkan hasil sepanjang 2 Maret hingga 30 September 2020, nilai tukar dan IHSG berpengaruh positif signifikan terhadap harga saham, sedangkan harga minyak berpengaruh tidak signifikan. DJI berpengaruh negatif tidak signifikan terhadap harga saham sedangkan DJIMI berpengaruh negatif signifikan. Sepanjang pandemi dapat dimungkinkan banyak variabel makro maupun mikro yang mengalami goncangan dan turut memberi pengaruh terhadap harga saham pada sub sektor hotel, restaurant dan pariwisata.Kata Kunci: Dow Jones Index, Dow Jones Islamic Market Index, Harga Minyak, IHSG, Nilai Tukar. ABSTRACTThe COVID-19 pandemic, which spreads rapidly around the world, has raised many impacts, including in economic sector. There are particular policies to prevent the spreading of COVID-19 virus, such as restrictions of mobilization and public activities which give some massive impacts, including the tourism sector. This study aims to see the impact of several macroeconomic variables, those are exchange rate, IHSG, Dow Jones Index (DJI), Dow Jones Islamic Market Index (DJIMI), and world oil price, due stock price fluctuations in the hotel, restaurant and tourism sub-sector companies listed on Indonesia Sharia Stock Index. Using Partial Least Square (PLS) method, it shows the results from March 2 to September 30 2020, exchange rate and IHSG have positive significant effect on stock price, while oil price has no significant effect. DJI has a negative and insignificant effect on stock price, while DJIMI has a negative significant effect. Through this pandemic, there are many macro or micro variables may experience shocks and give some contribution to the effect of sharia stock price in the hotel, restaurant and tourism sub-sector.Keywords: Dow Jones Index, Dow Jones Islamic Market Index, Exchange Rate, IHSG, Oil Price.
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Shaw, L., P. Helmholz, D. Belton, and N. Addy. "COMPARISON OF UAV LIDAR AND IMAGERY FOR BEACH MONITORING." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W13 (June 4, 2019): 589–96. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w13-589-2019.
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<p><strong>Abstract.</strong> With recent advancements in UAV based technology the use of airborne photogrammetry and LiDAR poses a new and effective approach for continuous, fast and efficient beach monitoring surveys. This paper aims to compare three platforms (a DJI Phantom Pro 4 using Ground Control Points, a DJI Matrice 200 with built in PPK allowing direct georeferencing and a DJI Matrice 600 with a Riegl Mini-VUX LiDAR system) in order to assess if they enable beach surveys to be performed efficiently, accurately and cost- effectively. A series of beach surveys were performed over a period of 6 months enabling the ability of each UAV surveying technique to be assessed for the identification and evaluation of trends in the changing topography of beaches and shorelines. The study area (Warnbro Sound, Western Australia) is an area that has experienced significant coastal change over the last 20 years as well as several serious weather events in the course of this research. The results show a significant positive bias of a consistent vertical offset to the ground surface by 4&ndash;9&thinsp;cm between the two image based systems in comparison to the LiDAR system. Although these height offsets are significant it is still within the accuracy required to perform successful beach surveys, and all systems were able to quantify the change of the beach shoreline in area (m<sup>2</sup>) and volume (m<sup>3</sup>).</p>
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Chiabrando, F., and L. Teppati Losè. "PERFORMANCE EVALUATION OF COTS UAV FOR ARCHITECTURAL HERITAGE DOCUMENTATION. A TEST ON S.GIULIANO CHAPEL IN SAVIGLIANO (CN) – ITALY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W6 (August 23, 2017): 77–84. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w6-77-2017.
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Even more the use of UAV platforms is a standard for images or videos acquisitions from an aerial point of view. According to the enormous growth of requests, we are assisting to an increasing of the production of COTS (Commercial off the Shelf) platforms and systems to answer to the market requirements. In this last years, different platforms have been developed and sell at low-medium cost and nowadays the offer of interesting systems is very large. One of the most important company that produce UAV and other imaging systems is the DJI (Dà-Jiāng Innovations Science and Technology Co., Ltd) founded in 2006 headquartered in Shenzhen – China. The platforms realized by the company range from low cost systems up to professional equipment, tailored for high resolution acquisitions useful for film maker purposes. According to the characteristics of the last developed low cost DJI platforms, the onboard sensors and the performance of the modern photogrammetric software based on Structure from Motion (SfM) algorithms, those systems are nowadays employed for performing 3D surveys starting from the small up to the large scale. <br><br> The present paper is aimed to test the characteristic in terms of image quality, flight operations, flight planning and accuracy evaluation of the final products of three COTS platforms realized by DJI: the Mavic Pro, the Phantom 4 and the Phantom 4 PRO. The test site chosen was the Chapel of San Giuliano in the municipality of Savigliano (Cuneo-Italy), a small church with two aisles dating back to the early eleventh century.
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Singha, Subroto, and Burchan Aydin. "Automated Drone Detection Using YOLOv4." Drones 5, no. 3 (September 11, 2021): 95. http://dx.doi.org/10.3390/drones5030095.
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Drones are increasing in popularity and are reaching the public faster than ever before. Consequently, the chances of a drone being misused are multiplying. Automated drone detection is necessary to prevent unauthorized and unwanted drone interventions. In this research, we designed an automated drone detection system using YOLOv4. The model was trained using drone and bird datasets. We then evaluated the trained YOLOv4 model on the testing dataset, using mean average precision (mAP), frames per second (FPS), precision, recall, and F1-score as evaluation parameters. We next collected our own two types of drone videos, performed drone detections, and calculated the FPS to identify the speed of detection at three altitudes. Our methodology showed better performance than what has been found in previous similar studies, achieving a mAP of 74.36%, precision of 0.95, recall of 0.68, and F1-score of 0.79. For video detection, we achieved an FPS of 20.5 on the DJI Phantom III and an FPS of 19.0 on the DJI Mavic Pro.
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Rahmad, Riki. "Pemanfaatan Drone DJI Phantom 4 Untuk Identifikasi Batas Administrasi Wilayah." JURNAL GEOGRAFI 11, no. 2 (August 1, 2019): 218–23. http://dx.doi.org/10.24114/jg.v11i2.10604.
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Kao, Da-Yu, Min-Ching Chen, Wen-Ying Wu, Jsen-Shung Lin, Chien-Hung Chen, and Fuching Tsai. "Drone Forensic Investigation: DJI Spark Drone as A Case Study." Procedia Computer Science 159 (2019): 1890–99. http://dx.doi.org/10.1016/j.procs.2019.09.361.
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Memdani, Laila, and Guruprasad Shenoy. "Impact of terrorism on stock markets across the world and stock returns." Journal of Financial Crime 26, no. 3 (July 2, 2019): 793–807. http://dx.doi.org/10.1108/jfc-09-2018-0093.
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Purpose The purpose of this paper is to study the following: short-run and long-run associations between the terror-affected country’s stock market index and other global countries’ equity indices and gold; the volatility of stock market indices when one of the countries is affected by a terrorist attack; and the linkages between terrorism and the returns in the selected stock markets. Design/methodology/approach To study the impact of the Taj attack on other global indices, the authors selected top five countries’ stock market indices, namely, FTSE, DJI, NIKKEI, SSEC and DAX. The short-run and long-run associations are also compared with gold. The authors used the autoregressive distributed lag model, LM test and bounds test for analyzing the short-run and long-run impact; ARCH family models to study the volatility impact; and the MAR model to study the impact on returns. Findings The authors found that all the global indices had a short-run association with the terror-affected country’s benchmark index, i.e. BSE. Gold moved as expected, with it having a short-run impact on the terror-affected country. All the global indices except DJI have volatility of share price movement either positively or negatively. As the benchmark of the terror-affected country fell, NIKKEI, HSI, IXIC, DAX and CAC also fell; that is, it had a positive influence on the terror-affected country’s index. Post the Mumbai attacks, DJI, NIKKEI, SSEC, DAX, BSE and CAC performed well in performance measure returns compared with the pre-attack period. Whereas, FTSE and GOLD performed well in performance measure returns in the pre-attack period compared with the post-attack period. GOLD proved that it is the best avenue to invest in, as it has only a short-term association with the terror-affected country’s index. Research limitations/implications The authors studied the short-run and long-run associations with only five countries’ benchmark indices. Practical implications The authors found that all the global indices had long- and short-run associations with the terror-affected country’s benchmark index, i.e. BSE. Global indices like DJI, NIKKEI, SSEC, DAX and FTSE had a short-term association with the affected country’s index. Gold moved as expected, with it having a short-run impact on the terror-affected country. All the global indices except DJI have volatility of share price movement either positively or negatively. As the benchmark of the terror-affected country fell, NIKKEI, HSI, IXIC, DAX, TSX, BVSP and CAC also fell; i.e., it had a positive influence on the terror-affected country’s index. Post the Mumbai attacks, DJI, NIKKEI, SSEC, DAX, BSE and CAC performed well in performance measure returns compared with the pre-attack period. Whereas, FTSE and GOLD performed well in performance measure returns in the pre-attack period compared with the post-attack period. GOLD proved that it is the best avenue to invest in, as it has only a short-term association with the terror-affected country’s index. In all the relationships were mixed with respect to terror attacks, and GOLD took the lead run out of all the associations it had in the 16-year time span from 2000 to 2016. Social implications The research has got an important implication to the investors. It shows that patience is the key, as all the indices had only short-term associations with the BSE. It implies that investors’ returns will be negative in the short run, but if they continue investing, in the long run, the impact of terrorism tapers out and the returns will increase. Originality/value There is a lot of research done on the impact of the US attacks on the stock markets of other countries, but on the impact of the Taj attack in India, there is hardly any research.
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Stankevich, Sergey, Mykola Lybskyi, and Artur Lysenko. "Aerial imaging superresolution based on subpixel processing of images acquired by quadcopter." Ukrainian journal of remote sensing, no. 15 (February 11, 2018): 40–42. http://dx.doi.org/10.36023/ujrs.2017.15.113.
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Insufficient spatial resolution is a common problem in aerial imaging. An approach for spatial resolution enhancement using several images of low spatial resolution with relative subpixel displacement for the superresolution is proposed. Demo example of superresolution of test aerial image acquired by 4K camera onboard DJI Phantom 4 quadcopter is described.
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Salamh, Fahad E., Mohammad Meraj Mirza, and Umit Karabiyik. "UAV Forensic Analysis and Software Tools Assessment: DJI Phantom 4 and Matrice 210 as Case Studies." Electronics 10, no. 6 (March 19, 2021): 733. http://dx.doi.org/10.3390/electronics10060733.
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Unmanned Aerial Vehicles (UAVs) also known as drones have created many challenges to the digital forensic field. These challenges are introduced in all processes of the digital forensic investigation (i.e., identification, preservation, examination, documentation, and reporting). From identification of evidence to reporting, there are several challenges caused by the data type, source of evidence, and multiple components that operate UAVs. In this paper, we comprehensively reviewed the current UAV forensic investigative techniques from several perspectives. Moreover, the contributions of this paper are as follows: (1) discovery of personal identifiable information, (2) test and evaluation of currently available forensic software tools, (3) discussion on data storage mechanism and evidence structure in two DJI UAV models (e.g., Phantom 4 and Matrice 210), and (4) exploration of flight trajectories recovered from UAVs using a three-dimensional (3D) visualization software. The aforementioned contributions aim to aid digital investigators to encounter challenges posed by UAVs. In addition, we apply our testing, evaluation, and analysis on the two selected models including DJI Matrice 210, which have not been presented in previous works.
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Lermen, Dominik, Lotte Glück, and Peter Schirmacher. "2016 ISBER Annual Meeting and Exhibits in Berlin—“Breaking Down Walls: Unifying Biobanking Communities to Secure Our Sustainability”." Biopreservation and Biobanking 14, no. 1 (February 2016): 84–86. http://dx.doi.org/10.1089/bio.2016.28999.dji.
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Wang, Hui, and R. B. Pandey. "Momentum analysis of DJI stocks near sharp rise, crash, and consolidation." Physica A: Statistical Mechanics and its Applications 334, no. 3-4 (March 2004): 524–30. http://dx.doi.org/10.1016/j.physa.2003.10.048.
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Aziz, Luthfi Abdul. "Representasi Identitas Nasionalisme Indonesia dalam Iklan Rokok Dji Sam Soe “Mahakarya”." CHANNEL: Jurnal Komunikasi 7, no. 2 (October 25, 2019): 125. http://dx.doi.org/10.12928/channel.v7i2.13576.
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Arambašić, Radmila. "IZRADA 3D MODELA PRIMJENOM BLISKO - PREDMETNE FOTOGRAMETRIJE." Zbornik radova Fakulteta tehničkih nauka u Novom Sadu 34, no. 10 (October 1, 2019): 1896–99. http://dx.doi.org/10.24867/04kg02arambasic.
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Predmet ovog rada jeste generisanje trodimenzionalne predstave Spomenika palim Krajišnicima kod Banja Luke, na osnovu snimaka iz vazduha prikupljenih bespilotnom letjelicom DJI Phantom 4 Advanced, u kombinaciji sa terstičkim snimcima sa zemlje prikupljenim digitalnom kamerom. Postupak modelovanja i vizuelizacije finalnog modela izvršeno je u sofveru Reality Capture, te je u okviru analize rada uključen pregled postignutih rezultata i ocjena njihove tačnosti.
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Arrochman, Ibnu Fajar, Dhomas Hatta Fudholi, and Yudi Prayudi. "PENGGUNAAN METODE STATIS DAN LIVE FORENSIK PADA UAV UNTUK MENDAPATKAN BUKTI DIGITAL." ILKOM Jurnal Ilmiah 11, no. 2 (August 31, 2019): 152–58. http://dx.doi.org/10.33096/ilkom.v11i2.444.152-158.
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In recent years, the use of drones by civilians is increasing rapidly by the presentation of total sales continued to increase rapidly every year. With the increasing possibility of Unmanned Aerial Vehicle (UAV) abuse, crime in the use of UAVs to be larger. Through forensic analysis of data using static forensic and live forensic to obtain data that allows it to be used as digital evidence. To dig up information that could be used as digital evidence in the UAV and controllers, as well as to know the characteristics of digital evidence on a UAV. The results showed that digital evidence on a UAV, the smartphone is used as a controller UAV has a very important role in the investigation. The findings in aircraft has a percentage of 50% and a camera memory card with 16.6%. DJI Phantom 3 Advanced GPS coordinates always store data in flight LOG; the data is always stored even when the flight mode is used does not use GPS signals to stability. Due to DJI Phantom 3 Advanced always use GPS on flights, file, image or video captured by the camera has the best GPS location coordinates to the metadata therein.
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Strauß, Nadine, Rens Vliegenthart, and Piet Verhoeven. "Intraday News Trading: The Reciprocal Relationships Between the Stock Market and Economic News." Communication Research 45, no. 7 (April 28, 2017): 1054–77. http://dx.doi.org/10.1177/0093650217705528.
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This study investigates the interdependent relationships between the stock market and economic news in the U.S. context. 2,440 economic tweets from Reuters and Bloomberg published in September 2015 were analyzed within short-term intervals (5 minutes, 20 minutes, and 1 hour) as well as 50 influential Bloomberg market coverage stories distributed via their terminals for the same period of time. Using Vector Auto Regression analyses, it was found that news volume, news relevance, and expert opinion in tweets seem to influence the fluctuation of the Dow Jones Industrial Average (DJI) positively, while economic news appears to respond to market fluctuation with less coverage, including fewer retweets, favorites, updates, or expert opinions conveyed. Inspecting the influential market stories by Bloomberg, the results imply that while Bloomberg terminals provide firsthand information on the market to professionals, tweets rather seem to offer follow-up reporting to the public. Furthermore, given that the effect of economic tweets on the DJI fluctuations was found to be strongest within longer time intervals (i.e., 1 hour), the findings imply that public traders need more time to evaluate information and to make a trading decision than professional investors.
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Kuželka, Karel, and Peter Surový. "Mapping Forest Structure Using UAS inside Flight Capabilities." Sensors 18, no. 7 (July 12, 2018): 2245. http://dx.doi.org/10.3390/s18072245.
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We evaluated two unmanned aerial systems (UASs), namely the DJI Phantom 4 Pro and DJI Mavic Pro, for 3D forest structure mapping of the forest stand interior with the use of close-range photogrammetry techniques. Assisted flights were performed within two research plots established in mature pure Norway spruce (Picea abies (L.) H. Karst.) and European beech (Fagus sylvatica L.) forest stands. Geotagged images were used to produce georeferenced 3D point clouds representing tree stem surfaces. With a flight height of 8 m above the ground, the stems were precisely modeled up to a height of 10 m, which represents a considerably larger portion of the stem when compared with terrestrial close-range photogrammetry. Accuracy of the point clouds was evaluated by comparing field-measured tree diameters at breast height (DBH) with diameter estimates derived from the point cloud using four different fitting methods, including the bounding circle, convex hull, least squares circle, and least squares ellipse methods. The accuracy of DBH estimation varied with the UAS model and the diameter fitting method utilized. With the Phantom 4 Pro and the least squares ellipse method to estimate diameter, the mean error of diameter estimates was −1.17 cm (−3.14%) and 0.27 cm (0.69%) for spruce and beech stands, respectively.
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Nghia, Nguyen Viet. "Building DEM for deep open-pit coal mines using DJI Inspire 2." Journal of Mining and Earth Sciences 61, no. 1 (February 28, 2020): 1–10. http://dx.doi.org/10.46326/jmes.2020.61(1).01.
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Using photo data of unmanned aerial vehicle (UAV) for building 3D models has been widely used in recent years. However, building a 3D model for deep open - pit coal mines with the mean height difference between surface and bottom of mines to over 500 m, there has not been researched mentioned. The paper deals with the assessment possibility of developing 3D models for deep open - pit mines from UAV image data. To accomplish this goal, DJI's Inspire 2 flying device is used to take the photo at Coc Sau coal mine. The flying area is 4 km2, the flight altitude compared to the takeoff point on the mine surface is 250 m, the overlaying coverage is both horizontal and vertical is 70%. The average errors of the horizontal and height elements of the reference points photo correlates are 0.011 m, 0.017 m, 0.016 m, 0.049 m, and 0.051 m. The maximum error on the X-axis is - 0,025 m, and the Y-axis is 0.028 m, the maximum horizontal error is 0.034 m, the maximum error on the Z-axis is 0.095 m, and the position error is 0.095 m. These results show that the 3D model established from photographic data by Inspire 2 device has satisfied the requirements of the accuracy of establishing the mining terrain map 1: 1000 scale.
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Seff, Faisal Mubarak, and Ridha Darmawaty. "Istikhdam Uslub Dji Sam Soe (234) fi Qira'ah An-Nushush Ghair Masykulah." An Nabighoh: Jurnal Pendidikan dan Pembelajaran Bahasa Arab 21, no. 02 (December 31, 2019): 155. http://dx.doi.org/10.32332/an-nabighoh.v21i02.1678.
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The superior ability to read Arabic texts without charity is a must for PBA students. But in reality they have difficulty in this because most of the material in the language language they study is rarely used in producing language, especially with the use of various terms that exacerbate these difficulties. Therefore, a strategy that is able to assist them in applying language rules in reading scripts with the use of simple terms and explanations is a must. And the strategy of Dji Sam Soe (234) is one solution with the character of the problem at hand. This study aims to describe the effectiveness of the strategy of Dji Sam Soe (234) in reading texts without a mark on cross-level PBA students in the 2016-2017 academic year by using the Quasi experimental design of one group time series design. Porpusif sampling is a sample selection technique, which is students in the third, fifth and seventh semester who have participated in Qiraatul Kutub supporting courses with instruments in the form of sentences and paragraphs. The results of this study indicate that there is an increase in the ability to read manuscripts without harakat in the form of sentences or paragraphs at each level, although the average ability is slightly different in the ability to read texts in paragraph forms, where seventh semester students are better than semesters three and five.
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Taddia, Y., F. Stecchi, and A. Pellegrinelli. "USING DJI PHANTOM 4 RTK DRONE FOR TOPOGRAPHIC MAPPING OF COASTAL AREAS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W13 (June 4, 2019): 625–30. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w13-625-2019.
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<p><strong>Abstract.</strong> Imagery acquisition systems by Unmanned Aerial Vehicles (UAVs) have been rapidly evolving within the last few years. In mapping applications, it is the introduction of a considerable amount of Ground Control Points (GCPs) that enables the final reconstruction of a real-scale framed model. Since the survey of GCPs generally requires the use of total stations or GNSS receivers in Real Time Kinematic (RTK), either with or without a Network approach (NRTK), this on-site operation is particularly time consuming. In addition, the lack of clearly image-recognizable points may force the use of artificial markers (signalised GCPs) whenever no features are naturally available in the field. This implies a real waste of time for the deployment of the targets, as well as for their recovery. Recently, aircrafts’ manufacturers have integrated the on-board RTK capability on their UAVs. In such a way, the high precision GNSS system allows the 3D position detection of the camera at the time of each capture within few centimetres. In this work, we tested the DJI Phantom 4 RTK for the topographic survey of a coastal section in the Northern Adriatic Sea (Italy). The flights were performed flying at an 80&thinsp;m altitude to ensure a Ground Sample Distance (GSD) of about 2 centimetres. The site extended up to 2 kilometres longitudinally. The results confirm that the on-board RTK approach really speeds up the precise mapping of coastal regions and that a single GCP may be needed to make a reliable estimation of the focal length.</p>
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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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HLOTOV, V., B. LADANIVSKYI, Z. KUZYK, A. BABUSHKA, and I. PETRYSHYN. "Development of the aerosurveying complex based on the DJI S1000 octocopter UAV." Modern achievements of geodesic science and industry 41, no. I (April 1, 2021): 86–96. http://dx.doi.org/10.33841/1819-1339-1-41-86-96.
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Goal. The purpose of the work is to develop an aerial photography complex based on a DJI S1000 helicopter UAV for aerial photography, which includes a laser scanner (LS) and a digital camera (CPC). Method. For several decades, aerial photography has been an effective tool for geodetic works, geophysical surveys and various types of monitoring. On the other hand, the use of not only digital imaging, but also laser scanning of objects allows to maximize the accuracy of obtaining the coordinates of points on the ground and eliminate such a process as plan-height binding in the field, which occupies more than 80 % of field work that is, much cheaper the process of creating cartographic materials. In addition, the use of laser scanners on board unmanned aerial vehicles helps to solve a number of scientific and applied problems in various fields, such as engineering research, environmental monitoring, landscape research and modeling, construction, architecture, archeology and more. Comprehensive study, research and monitoring of the environment involves the availability and use of highly efficient modern technologies, special software for data processing and analysis and qualified human resources. Aerial laser scanners are the latest high-precision technology for obtaining data about the object by noncontact method and have a multi-purpose purpose. I have been actively using them in the world since the early 2000s. They have a number of advantages over traditional aerial photography. Drugs are manufactured by the world’s leading companies, they are available on the market and are in great demand among foreign specialists. Unfortunately, in Ukraine, airborne laser scanners are used in limited quantities to perform special tasks with the involvement of foreign experts. In this area we have a significant lag compared to other European countries. Therefore, the acquisition and application of such a software and technology complex and UAV will help solve and accelerate the solution of many important scientific and applied problems in Ukraine, as well as increase the potential, opportunities and prestige in domestic and world science and practice. Results. A mock-up model of installation and implementation of Velodyne VLP-16 on a DJI S1000 helicopter UAV has been developed. The authors analyzed the known systems and created the best option for connecting and connecting the elements, which made it possible to simplify the layout of the devices, which in turn made it possible to reduce the cost of the proposed complex. Scientific novelty and practical significance. For the first time in Ukraine, a method of installing a helicopter-type UAV was developed and proposed. With the help of an airborne laser scanning system installed on board an unmanned aerial vehicle of helicopter type it is possible to solve a number of important scientific and applied tasks, such as: monitoring the technical condition of large and hard-to-reach structures – nuclear, hydro and thermal power plants, power lines, etc. ; monitoring the condition of roads, detecting places of surface damage and other dangerous places in order to prevent car accidents; detection of damage to forests and agricultural lands; observation and prevention of landslides in mountains and industrial quarries, places of soil erosion; monitoring of water resources, changes in contours and heights of the coastal strip; detection of roof defects, deformations, wall cracks on highrise buildings for architectural measurements, 3D modeling, documentation and preservation of cultural heritage sites; assistance in archaeological exploration to identify archaeological sites and study artifacts. In addition, peripheral drugs can be installed on other moving objects (cars, railcars, boats, etc.) and scanning from fixed bases in stationary conditions.
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Фесенко, Г. "Особливості визначення оптимального плану використання флотів БПЛА заданого радіусу дії для моніторингу об’єктів на території атомних станцій." Науковий журнал «Інженерія природокористування», no. 4(14) (February 24, 2020): 62–67. http://dx.doi.org/10.37700/enm.2019.4(14).62-67.
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Запропоновано алгоритм визначення оптимальної сукупності флотів БПЛА угруповання для моніторингу заданих точок на території 30-кілометрової зони Запорізької АЕС для різних критеріїв оптимізації. Показана можливість застосування запропонованого алгоритму для визначення оптимального плану використання угруповання з 6 флотів БПЛА для моніторингу 10 постів контролю автоматизованої системи контролю радіаційної обстановки Запорізької АЕС. Зони спостереження для кожного з флотів БПЛА сформовано відповідно до радіусу їх дії. Показано, що радіус дії кожного флоту визначається з урахуванням часового ресурсу батареї та швидкості БПЛА, відстані між стартовою позицію та постом контролю, а також часу моніторингу. Розглянуто два варіанти комплектування флотів БПЛА. В першому випадку всі флоти укомплектовані БПЛА DJI MAVIC AIR. У другому варіанті комплектування у складі третього флоту використано БПЛА Parrot Bebop-Pro Thermal. У якості критеріїв оптимізації обрано загальну кількість флотів для виконання моніторингу (основний критерій), та сумарний час виконання угрупованням флотів БПЛА моніторингу постів контролю. У якості методу оптимізації використано метод послідовник поступок. Показано, що для запропонованих вихідних даних заміна БПЛА Parrot Bebop-Pro Thermal на БПЛА DJI MAVIC AIR у третьому флоті дозволяє зменшити як кількість залучених для моніторингу флотів (з чотирьох до 2 одиниць), так і сумарний час виконання угрупованням флотів моніторингу (на 33,2 хвилини). Отримані результати доцільно використовувати для обґрунтування складу флотів БПЛА та їх розміщення під час виконання ними завдань щодо моніторингу елементів інфраструктури потенційно небезпечних об’єктів.
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Huang, Jingjing, and Danlei Gu. "Multiscale Multifractal Detrended Cross-Correlation Analysis of High-Frequency Financial Time Series." Fluctuation and Noise Letters 18, no. 03 (July 16, 2019): 1950014. http://dx.doi.org/10.1142/s0219477519500147.
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In order to obtain richer information on the cross-correlation properties between two time series, we introduce a method called multiscale multifractal detrended cross-correlation analysis (MM-DCCA). This method is based on the Hurst surface and can be used to study the non-linear relationship between two time series. By sweeping through all the scale ranges of the multifractal structure of the complex system, it can present more information than the multifractal detrended cross-correlation analysis (MF-DCCA). In this paper, we use the MM-DCCA method to study the cross-correlations between two sets of artificial data and two sets of 5[Formula: see text]min high-frequency stock data from home and abroad. They are SZSE and SSEC in the Chinese market, and DJI and NASDAQ in the US market. We use Hurst surface and Hurst exponential distribution histogram to analyze the research objects and find that SSEC, SZSE and DJI, NASDAQ all show multifractal properties and long-range cross-correlations. We find that the fluctuation of the Hurst surface is related to the positive and negative of [Formula: see text], the change of scale range, the difference of national system, and the length of time series. The results show that the MM-DCCA method can give more abundant information and more detailed dynamic processes.
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Zerle, Claudia, Waltraud Cornelißen, and Walter Bien. "Das Timing der Familiengründung und dessen Folgen für Familien." Journal of Family Research 24, no. 1 (April 1, 2012): 46–66. http://dx.doi.org/10.20377/jfr-191.
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Little is known about the consequences of the timing of family formation for the living conditions, the civil status, the conduct of life and the well-being of mothers, fathers and their children. This study is based on the DJI Survey AID:A, and the official statistics of the 2007 German Microcensus. The analysis includes considerations about the definition of “early” and “late” parenthood. Results: Living conditions, educational background, marital status and the stability of partnership vary by the timing of the first child. The timing of family formation hardly has an impact on the time that parents spend with their first child nor does it influence their contentment.
Zusammenfassung
Ausgehend vom lückenhaften Forschungsstand zu den Folgen des Timing von Elternschaft für die Lebenslage, Lebensform, und Lebensführung von Müttern, Vätern und Kindern werden Hypothesen zu diesem Zusammenhang entwickelt und anschließend mit Daten des DJI-Surveys AID:A für die Familiengründungsphase überprüft. Wo möglich, werden die Befunde mit Daten aus dem Mikrozensus 2007 validiert. Der Analyse sind Überlegungen zur Definition von „früher“ und „später“ Elternschaft vorgeschaltet. Die Untersuchung zeigt, dass zentrale Aspekte der sozialen Lage und der Institutionalisierungsgrad der Paarbeziehung mit dem biografischen Zeitpunkt der Familiengründung variieren. Das Zeitbudget für das Kind und die Zufriedenheit der Eltern werden durch den biografischen Zeitpunkt der Familiengründung aber kaum beeinflusst.
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Ammar, Adel, Anis Koubaa, and Bilel Benjdira. "Deep-Learning-Based Automated Palm Tree Counting and Geolocation in Large Farms from Aerial Geotagged Images." Agronomy 11, no. 8 (July 22, 2021): 1458. http://dx.doi.org/10.3390/agronomy11081458.
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In this paper, we propose an original deep learning framework for the automated counting and geolocation of palm trees from aerial images using convolutional neural networks. For this purpose, we collected aerial images from two different regions in Saudi Arabia, using two DJI drones, and we built a dataset of around 11,000 instances of palm trees. Then, we applied several recent convolutional neural network models (Faster R-CNN, YOLOv3, YOLOv4, and EfficientDet) to detect palms and other trees, and we conducted a complete comparative evaluation in terms of average precision and inference speed. YOLOv4 and EfficientDet-D5 yielded the best trade-off between accuracy and speed (up to 99% mean average precision and 7.4 FPS). Furthermore, using the geotagged metadata of aerial images, we used photogrammetry concepts and distance corrections to automatically detect the geographical location of detected palm trees. This geolocation technique was tested on two different types of drones (DJI Mavic Pro and Phantom 4 pro) and was assessed to provide an average geolocation accuracy that attains 1.6 m. This GPS tagging allows us to uniquely identify palm trees and count their number from a series of drone images, while correctly dealing with the issue of image overlapping. Moreover, this innovative combination between deep learning object detection and geolocalization can be generalized to any other objects in UAV images.
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Song, C. Y., and J. Kim. "NUMERICAL STUDY FOR AERODYNAMIC PERFORMANCE OF DJI MAVIC PRO PLATINUM BY USING SIMERICS." Journal of Computational Fluids Engineering 26, no. 1 (March 31, 2021): 33–43. http://dx.doi.org/10.6112/kscfe.2021.26.1.033.
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Hinge, L., J. Gundorph, U. Ujang, S. Azri, F. Anton, and A. Abdul Rahman. "COMPARATIVE ANALYSIS OF 3D PHOTOGRAMMETRY MODELING SOFTWARE PACKAGES FOR DRONES SURVEY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W12 (February 21, 2019): 95–100. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w12-95-2019.
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<p><strong>Abstract.</strong> Drones are becoming popular in spatial mapping or survey. The use of drones survey can be seen from it low flying heights (capable to create a clear images), accessible on difficult or non-friendly vehicle access areas, faster data acquisition and higher data resolution henceforth improve the quality of the survey. However, this paper focuses on the post-processing of drone images for 3D surface modeling. With the motivation of producing better 3D models, four software packages are used for comparison. Those software packages are eyesMap3D, Drone Deploy, Agisoft PhotoScan and Pix4Dmapper. The equipment used to ensure a high level of quality model is the Leica GPS1200+ stationary GPS module and the DJI Phantom 4 PRO drone. The Leica GPS1200+ stationary GPS module were used to track the exact position of tie points on the ground. Meanwhile the DJI Phantom 4 PRO drone is used as data inputs (images) for the software packages stated. In addition, the drone is used to fly over a golf course, with a challenge of homogenous surface for 3D surface modeling. Based on the output, it shows that each software packages produces slightly different outputs. This paper summarizes the outputs and discusses the key elements in each software packages. This variation might be useful for future references in 3D surface modeling that can conform in different applications requirements.</p>
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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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Taddia, Y., C. Corbau, E. Zambello, V. Russo, U. Simeoni, P. Russo, and A. Pellegrinelli. "UAVS TO ASSESS THE EVOLUTION OF EMBRYO DUNES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W6 (August 24, 2017): 363–69. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w6-363-2017.
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The balance of a coastal environment is particularly complex: the continuous formation of dunes, their destruction as a result of violent storms, the growth of vegetation and the consequent growth of the dunes themselves are phenomena that significantly affect this balance. This work presents an approach to the long-term monitoring of a complex dune system by means of Unmanned Aerial Vehicles (UAVs). Four different surveys were carried out between November 2015 and November 2016. Aerial photogrammetric data were acquired during flights by a DJI Phantom 2 and a DJI Phantom 3 with cameras in a nadiral arrangement. GNSS receivers in Network Real Time Kinematic (NRTK) mode were used to frame models in the European Terrestrial Reference System. Processing of the captured images consisted in reconstruction of a three-dimensional model using the principles of Structure from Motion (SfM). Particular care was necessary due to the vegetation: filtering of the dense cloud, mainly based on slope detection, was performed to minimize this issue. Final products of the SfM approach were represented by Digital Elevation Models (DEMs) of the sandy coastal environment. Each model was validated by comparison through specially surveyed points. Other analyses were also performed, such as cross sections and computing elevation variations over time. The use of digital photogrammetry by UAVs is particularly reliable: fast acquisition of the images, reconstruction of high-density point clouds, high resolution of final elevation models, as well as flexibility, low cost and accuracy comparable with other available techniques.