2,833 research outputs found

    Use of YOLOv5 object detection algorithms for insect detection

    Get PDF
    Climate change affects global temperature and precipitation patterns that influence the intensity and, in some cases, the frequency of extreme environmental events, such as forest fires, hurricanes and storms. These events can be particularly conducive to the increase of plant pests and diseases, which causes significant production losses. So, the early detection of pests is of the main importance to reduce pest losses and implement more safe control management strategies protecting the crop, human health, and the environment (e.g., precision in the pesticide application). Nowadays, pests’ detection and prediction are mainly based on counting insects on attacked organs or in traps by experts, but this is a costly and time-consuming task for extensive and geographically dispersed olive groves. Machine learning algorithms, using image analysis, can be used for autonomous pests’ detection and counting. In the present practical work, YOLOv5 was chosen to detect and count the olive fly adults (Bactrocera oleae Rossi), a key pest of olives. YOLOv5s architecture of YOLO’s algorithm was used to test its efficiency in olive fly detection on a mobile deployment solution. The results obtained were quite satisfactory, and the experimental results obtained have been analyzed and presented, encompassing a set of metrics such as precision, recall, and the mean average precision. This study will be extended for other pests and disease detection in future work. Also, this solution will be integrated into a web-based information and management service (with sensors and e-traps) that remotely detect the presence and severity of pest attacks.This work is financed by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia, within project .info:eu-repo/semantics/publishedVersio

    Parent Actions, Dualities and New Weyl-invariant Actions of Bosonic p-branes

    Get PDF
    By using the systematic approach of parent action method, we derive one Weyl-noninvariant and two Weyl-invariant actions of bosonic pp-branes (p≥2p\geq 2) starting from the Nambu-Goto action, and establish the duality symmetries in this set of four actions. Moreover, we discover a new bosonic pp-brane action (including the string theory) and deduce two corresponding Weyl-invariant formulations by proposing a new special parent action. We find that the same duality symmetries as those mentioned above exist in this new set of actions. The new pp-brane actions are also briefly analyzed.Comment: 19 pages, 14 figures. The first section is modified slightly, and references are adde

    Discrimination of varietal olive oils of the portuguese cultivars Cobrançosa, Madural and Verdeal based on their fatty acids composition

    Get PDF
    The fatty acid composition has been traditionally used to discriminate the different vegetable oils and confirm their authenticity. The aim of the present study was to check the possible use of the fatty acid profile to differentiate varietal olive oils of the three most important cultivars in Northeast Portugal (Cobrançosa, Madural and Verdeal). Fifteen varietal olive oils from each of the three cultivars were collected to achieve that goal. Fatty acids were determined, as methylesters, by HRGC. Methylesters were prepared by transesterefication with BF3/methanol after saponification with methanolic KOH. The fatty acid pattern was performed with a Chrompack CP9001 equipped with a split-splitless injector, a FID and a 50m x 0,25 mm i.d. fused silica capillary column coated with a 0.19µm film of CP-Sil88 (Chrompack). The temperatures of injector, detector and oven were 230, 250 and 185ºC, respectively. The results as shown by two-way Anova techniques and discriminant analysis demonstrate that C16:1c, C17:1, C18, C18:1c, C18:2cc and C18:3ccc can be used to discriminate the origin of each of the three olive oils

    Effect of olive fruit fly infestation on the quality of olive oil from cultivars cobrançosa, madural and verdeal transmontana

    Get PDF
    Olives (Olea europaea L.) from cultivars Cobrançosa, Madural and Verdeal Transmontana were collected separately and divided into two different groups according to the presence or absence of infestation by the olive fruit fly (Bactrocera oleae Gmel.). These two groups were then mixed in varying percentages to create five groups of olives per cultivar with infestation levels: 0, 12.5, 25, 50 and 100%. Each group was then processed to produce olive oil. The results, regarding mainly acidity, peroxide value, and stability to oxidation, suggest that olive fruit fly infestation reduces the quality of the olive oil. The effects of infestation varied according to cultivar, but in general the total tocopherol content was always lower at the 100% infestation level. The oil from cultivar Verdeal Transmontana had the lowest tocopherol content compared to oil from cultivars Cobrançosa and Madural, which could explain the lower quality of its oil

    Intelligent monitoring and management platform for the prevention of olive pests and diseases, including IoT with sensing, georeferencing and image acquisition capabilities through computer vision

    Get PDF
    Climate change affects global temperature and precipitation patterns. These effects, in turn, influence the intensity and, in some cases, the frequency of extreme environmental events, such as forest fires, hurricanes, heat waves, floods, droughts, and storms. In general, these events can be particularly conducive to the appearance of plant pests and diseases. The availability of models and a data collection system is crucial to manage pests and diseases in sustainable agricul-tural ecosystems. Agricultural ecosystems are known to be complex, multivariable, and unpredict-able. It is important to anticipate crop pests and diseases in order to improve its control in a more ecological and economical way (e.g., precision in the use of pesticides). The development of an intel-ligent monitoring and management platform for the prevention of pests and diseases in olive groves at Trás-os- Montes region will be very beneficial. This platform must: a) integrate data from multi-ple data sources such as sensory data (e.g., temperature), biological observations (e.g., insect counts), georeferenced data (e.g., altitude) or digital images (e.g., plant images); b) systematize these data into a regional repository; c) provide relevant forecasts for pest and diseases. Convolutional Neural Networks (CNNs) can be a valuable tool for the identification and classi-fication of images acquired by Internet of Things (IoT).info:eu-repo/semantics/publishedVersio

    Continuous Micro-Environments Associated Orchid Bees Benefit from an Atlantic Forest Remnant, Paraná State, Brazil

    Get PDF
    The fragmentation and habitat loss are the main causes of pollinators decline worldwide, however very little is known about the composition and distribution of neotropical pollinators along continuous micro-environments. To fill this gap, we carried out samplings of Euglossini bees in a continuous area of forest with micro-environments of primary (remnant) and secondary (regeneration) forest of Atlantic Forest. We evaluated the differences in the composition and uniformity of orchid bees in different micro-environments, in order to characterize the responses of the local environmental changes in the attraction of bees to chemical traps. Our results indicated that the composition and uniformity were similar between the two forest fragments studied here, although there are greater abundance of some species by micro-environments. We conclude that the characteristics of the sites in a continuous environment with primary and secondary forest do not seem to have an effect on the composition of the Euglossini fauna, and that the chemical substances are complementary in the attractiveness of the orchid bee males. Thus, our findings suggest that micro-environments in a continuous matrix near forest remnants can help to promote the reintegration of the orchid bee communities and contribute to the conservation of areas in process of forest regeneration

    Assessment of a low-cost solar water heating systems in farrowing facilities

    Get PDF
    ArticleThe objective of this study was to develop a prototype solar heater using alternative materials and then to compare its thermal efficiency against that of two other commercial solar heating systems when heating the floor of piglet housing. To evaluate the thermal heaters, temperature sensors were installed in the inlet and outlet of each floor and the thermal reservoir. The results showed good performance, however the thermal efficiency of the alternative heater was lower than the conventional systems. However, due to the construction of this solar collector with alternative materials its cost was relatively low and its operation is easier than the other conventional heater, therefore this heater is a good alternative to use for small livestock producer

    Classification PDO olive oils on the basis of their sterol composition by multivariate analysis

    Get PDF
    The sterol compositions (GLC/FID/capillary column) of monovarietal olive oils (51 samples) from the most important cultivars of northeastern Portugal (Cvs. Cobranc¸osa, Madural and Verdeal Transmontana) and 27 commercial samples of olive oils with protected denomination of origin (PDO) from the same region and cultivars were evaluated. Δ-sitosterol, Δ5-avenasterol and campesterol were the most representative sterols. Cholesterol, stigmasterol, clerosterol and Δ7-stigmastenol were also found in all samples. All studied samples respected EC Regulation N. 2568, and in all cases total sterols were remarkably higher than the minimum limit set by legislation, ranging from 2003 to 2682 mg/kg. Results were analysed with the help of several statistical techniques, including reduction of dimensionality by principal component analysis with cross-validation of the number of components, followed by the use of canonical variate predictive biplots for model development and canonical variate interpolative biplots for approximate classification of monovarietal and PDO olive oils. These biplots proved to be a very interesting solution in the present case study, overcoming the problems of interpretation and classification that arise whenever different multivariate analyses are coupled together

    Interface state contribution to the photovoltaic effect in organic phototransistors:Photocapacitance measurements and optical sensing

    Get PDF
    Made available in DSpace on 2018-12-11T16:50:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Instituto Nacional de Ciência e Tecnologia em Eletrônica OrgânicaWe report the results of an investigation into the contribution that trapping in interface states makes to the photovoltaic effect observed in organic phototransistors. To isolate this effect from other processes that occur in the transistor structure when under illumination, we focus attention on the photo-response of metal-insulator-semiconductor (MIS) capacitors - the core structure of transistors. The capacitors comprised poly(3-hexylthiophene), (P3HT), as the active semiconductor in combination with one of three insulators, namely, poly(amide-imide), (PAI), SU-8 photoresist and polysilsesquioxane (PSQ). Following initial characterization in the dark, the capacitor response was measured both during and after irradiation with light in the wavelength range 400–700 nm. Three different approaches were employed to study the photo-response, each providing a different insight into the processes occurring. Capacitance-voltage sweeps before, during and after illumination provided direct evidence supporting the view that the photovoltaic effect occurred as a result of electron trapping in interface states of density up to ∼2 × 1012 cm−2 in the P3HT/PAI combination but lower for SU-8 and PSQ. The dynamic photo-response, in which device capacitance was held constant by changing the applied bias, showed a fast component related to optically induced photoconduction in the semiconductor and a slower component reflecting the dynamics of interface electron trapping. Finally, photo-induced capacitance changes occurring with constant applied voltage were used to demonstrate a simple 3 × 3 imaging array.School of Electronic Engineering Bangor University, Dean StreetBrazilian Nanotechnology National Laboratory (LNNano) Brazilian Centre of Research in Energy and Materials (CNPEM)Department of Physics São Paulo State University (UNESP), PO Box 266Institute of Physics of São Carlos University of São Paulo (USP), PO Box 369Catarinense Federal Institute of Education Science and Technology, PO Box 21Department of Physics São Paulo State University (UNESP), PO Box 26

    Conformal p-branes as a Source of Structure in Spacetime

    Get PDF
    We discuss a model of a conformal p-brane interacting with the world volume metric and connection. The purpose of the model is to suggest a mechanism by which gravity coupled to p-branes leads to the formation of structure rather than homogeneity in spacetime. Furthermore, we show that the formation of structure is accompanied by the appearance of a multivalued cosmological constant, i.e., one which may take on different values in different domains, or cells, of spacetime. The above results apply to a broad class of non linear gravitational lagrangians as long as metric and connection on the p-brane manifold are treated as independent variables.Comment: 10 pages, ReVTeX, no figure
    • …
    corecore