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Computers and Electronics in Agriculture
Elsevier Science Publishers
Computers and Electronics in Agriculture

Elsevier Science Publishers

0168-1699

Computers and Electronics in Agriculture/Journal Computers and Electronics in AgricultureSCIEIISTP
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    Evidence of parameters underestimation from nonlinear growth models for data classified as limited

    Zarzar C.A.Silva E.M.Fernandes T.J.De Oliveira I.R.C....
    12页
    查看更多>>摘要:? 2022 Elsevier B.V.Some growth data in aquaculture have peculiar characteristics that generate consequences in the analysis and modeling. They are usually incomplete or limited, as classified in this article. This means data are restricted to a few observations and often are limited to observations below the curve's inflection point due to economic interests in farm settings, or due to limitation of physical space in controlled research laboratories, for example. This possibly causes under and/or overestimation in the inference of nonlinear models. Through shrimp growth simulations from the Michaelis–Menten curve, the limited data were synthesized with threshold observation up to the first 7, 13, 18, 36, and 82 weeks. Seven sigmoid growth functions (Logistic, Gompertz, von Bertalanffy, Richard, Weibull, Morgan–Mercer–Flodin, and the own Michaelis–Menten growth) were fitted to respective limited data, in order to assess the research hypothesis. Taking the scenarios with incompleteness in the first 7, 13 and 18 weeks, the parameters of all growth curves modeled under a frequentist approach were underestimated. Thus, we propose a correction for this possible problem through a hierarchical Bayesian approach. Real data from shrimp farming in northeastern Brazil were used to compare it with the traditional frequentist approach employed. The sensitivity in detecting outstanding treatment (pond or batch level hierarchy) can make the new method a powerful management tool in animal production, and also in trials designed for scientific research.

    SPAD monitoring of saline vegetation based on Gaussian mixture model and UAV hyperspectral image feature classification

    Ding J.Zhang Z.Zhu C.Wang J....
    8页
    查看更多>>摘要:? 2022 Elsevier B.V.The chlorophyll content of saline vegetation can indirectly reflect salinization. Rapid and non-destructive capture of chlorophyll content of saline vegetation at a regional scale is essential for saline soil improvement and sustainability of saline agriculture. However, traditional soil–plant analyzer development (SPAD) monitoring based on SPAD-502 is carried out at the leaf scale, which does not allow rapid access to SPAD information for the whole region. In this study, we proposed that post-hyperspectral classification based on spectral differences that could contribute to enhanced estimation of SPAD in saline vegetation. To test this proposal, we partitioned the hyperspectral images using a Gaussian mixture model. Then, estimation models based on spectral partition and full-sample SPAD were developed using in situ observation data and a random forest model, respectively. Finally, the unmanned aerial vehicles (UAV) hyperspectral images were used as the input data source to digitally map the SPAD of saline vegetation in the region, using the prediction model. The results indicated that there were significant intensity and shape differences in the spectral reflectance characteristics of saline vegetation under different clusters. The SPAD prediction model, based on spectral feature partition, performed significantly better than the full sample. The SPAD maps of saline vegetation before and after clustering displayed similar spatial distribution models, but the prediction uncertainty of the models, based on spectral feature partition, was relatively low. Our results confirm the effectiveness and stability of UAV hyperspectral and spectral partition-based modeling in developing SPAD spatial distribution estimation models for saline vegetation.

    Development and testing of a grain combine harvester throughput monitoring system

    Zhang Y.Chen D.Dai D.Yin Y....
    8页
    查看更多>>摘要:? 2022Throughput is a key performance indicator of combine harvesters and an important basis for the control of its operating speed and loss rate. Current throughput monitoring methods are limited by low accuracy, weak stability, and poor applicability. Aimed at the real-time, accurate, and reliable detection of combine harvester throughput, we propose a throughput monitoring method based on multi-sensor decision level fusion and build a grain combine harvester throughput monitoring system (TMS). The experimental analysis method investigates the correlations of operation speed, crop density, feeding auger torque, conveyor torque, and cylinder torque with throughput, with single variable prediction models of throughput being established. Based on the findings, fusion calculations are conducted with throughput predicted using the single variable prediction models as the inputs and the correlation degrees of different variables with the throughput as the decision weight. Additionally, variations in the prediction results using different variables and results calculated by the decision-level fused model are employed for dynamic correction of the model. In this way, accurate detection of throughput is achieved. Field tests demonstrate that the maximum absolute error, average absolute error, maximum relative error, average relative error, and maximum root mean square error (RMSE) of the throughput monitoring of three combine harvesters by the proposed TMS are 0.49 kg/s, 0.2 kg/s, 4.9 %, 3.3 %, and 0.31 kg/s, respectively. The average absolute error, average relative error, and RMSE of the throughput monitoring of the three combine harvesters by the proposed TMS are 0.19 kg/s, 3.1 %, and 0.22 kg/s, respectively, thus suggesting high monitoring accuracy and stability, as well as good compatibility with various combine harvesters. This study provides important technical support for detection in the study of intelligent control technologies for combine harvesters.

    A CFD transient model of leaf wetness duration on greenhouse cucumber leaves

    Liu R.Liu K.Yang X.Liu H....
    11页
    查看更多>>摘要:? 2022The estimation of leaf wetness duration (LWD) is important for crop disease monitoring and early warning, because LWD provides the necessary conditions for pathogen infection. Crop canopy condensation caused by high humidity in greenhouses is one of the main causes of LWD formation, and measuring LWD in greenhouses is difficult. A simulation model based on agricultural meteorological parameters is typically used to replace field measurements. This study was conducted in a Chinese solar greenhouse. A 2D transient model based on computational fluid dynamics (CFD) was used to estimate the distribution of cucumber leaf condensation in a solar greenhouse during early summer nights in Beijing. The LWD was estimated by considering the duration of the simulated leaf condensation at each point and simulating the dehumidification effect under ventilation conditions. The visual observations of leaf condensation were compared with the simulation results from May 31 to June 1 and from June 3 to June 4, 2021 (cloudy and clear days, respectively). The horizontal leaf condensation was observed first near the south roof, whereas the vertical canopy had a longer LWD at 1 m from the ground (average value of 8 h). LWD was estimated using relative humidity thresholds (RMSE of 1.944 h on cloudy days and RMSE of 0.5 h on clear days), and the good agreement between measurements and estimation indicated that the 2D CFD model combined with the relative humidity threshold method could be used to estimate the temporal and spatial distribution of canopy LWD.

    Deep segmentation and classification of complex crops using multi-feature satellite imagery

    Wang L.Wang J.Zhang X.Qin F....
    15页
    查看更多>>摘要:? 2022 Elsevier B.V.Accurate remote sensing-based land use and crop maps provide important and timely information for decision support in large-scale agricultural monitoring. Most existing multi-crop products for complex agricultural areas based on traditional machine learning algorithms are not suitable for large agricultural management because of the poor model transfer capabilities. Therefore, a deep segmentation and classification model including spatiotemporal transfer across regions and years must be developed. In this study, a deep learning approach was developed based on the UNet++ architecture by integrating feature fusion and upsampling of small samples for large-scale land use and crop mapping. Classification experiments were conducted for ten categories at four sites using 10 m resolution Sentinel-2A images from 2019 to 2021 containing 4,194,304 pixels. The joint loss, including the label smoothing cross entropy and Dice coefficient, and the mean intersection over union (mIoU) were used to evaluate the model performance depending on different features and upsampling schemes. The joint loss and mIoU values of the training model and the prediction accuracies of the test sites indicate that the scheme including the upsampling and fusion of spectral bands, vegetation indices, and texture features yields the optimal model performance. For comparison, UNet, DeepLab V3+, Pyramid Scene Parsing Network (PSPNet), and random forest models were built. The improved UNet++ model exhibits the best performance, with an overall accuracy, kappa, and macro F1 above 91 %, 85 %, and 51 %, respectively. The deep segmentation and classification results without training samples demonstrate the spatiotemporal transfer capability of the UNet++ architecture during the key crop growth period. The patch parameter values also indicate that the improved model exhibits a better shape compactness and significantly reduces and suppresses patch fragmentation. Based on the analysis of the overall confusion matrix, the proposed method improves the classification accuracy for datasets with imbalanced land cover and crop types. This study provides a strategy for large-scale and complex land use and crop mapping based on the integration of feature fusion and deep learning.

    Label-free detection of maize kernels aging based on Raman hyperspcectral imaging techinique

    Long Y.Tang X.Zhang B.Wang Q....
    10页
    查看更多>>摘要:? 2022 Elsevier B.V.The feasibility of Raman hperspectral imaging technique was explored to detect maize kernels aging during storage to eliminate its negative effects on maize sowing and storage. Both TTC test and germination test were employed to evaluate the viability of maize kernels and the anlysis based on pixel-level and object-level were conducted. Different variable selection algorithms were used for screening of key features related with viability and three modeling methods were performed to classify maize kernels viability. In addition, Whale Optimization Algorithm(WOA) optimization algorithm was brought in to improve the accuracy of viability classification. The results showed that object-level method was more suitable for the classification of maize kernels viability. The fusion SVM model optimized by WOA coupled with CARS and VCPA-IRIV algorithm achieved the satifactory performance. In general, Raman hperspectral imaging techinique could be used as a poweful alternative for the nondestructive detection of maize kernels aging.

    Cascade-SORT: A robust fruit counting approach using multiple features cascade matching

    He L.Wu F.Du X.Zhang G....
    11页
    查看更多>>摘要:? 2022 Elsevier B.V.Estimation of fruit yield is of great importance to agricultural management and production decision-making. Fruit counting based on computer vision is faced with many challenges, particularly dense occlusion and difficult detection. To address the problems that exist in agricultural scenarios, we propose a fruit counting pipeline based on multiple features matching. Fruit counting is regarded as a multiple object tracking problem based on tracking-by-detection framework. The proposed method combines object detection with deep learning, Kalman filter, and cascade matching, which integrated motion and appearance features for frame-by-frame data association. Using the detection results of YOLO-v3, cascade matching is leveraged to associate detection bounding boxes with tracks. In cascade matching, the appearance features of fruit, Mahalanobis distance, and intersection over union metric were fused to match objects frame-by-frame. Mahalanobis distance is used to screen detection bounding boxes initially. Furthermore, the vector of locally aggregated descriptors image retrieval method is used to calculate the similarity of appearance between the two objects. In the final step of cascade matching, residual unmatched tracks and detection candidates are matched using intersection over union metric. Moreover, the Kalman filter is optimized for predicting the trajectories of undetectable objects to enhance the accuracy and robustness of fruit counting. In the experiments, the results of predicted fruit counting for camellia is 44 while the ground truth is 38 for a video. For apple counting, the total predicted number of fruits for three videos is 310 while the actual number is 292. And compared to the method of SORT, our method is better in counting accuracy, reduced the number of ID switches, and had more robustness when the detector performance degenerated. All the above mentioned metrics indicate that the proposed method is well performance in fruit counting regardless of whether the fruit is sparsely or densely grown.

    Barriers to computer vision applications in pig production facilities

    Dilger R.N.Condotta I.C.F.S.Lucic A.Aldridge B....
    14页
    查看更多>>摘要:? 2022 Elsevier B.V.Surveillance and analysis of behavior can be used to detect and characterize health disruption and welfare status in animals. The accurate identification of changes in behavior is a time-consuming task for caretakers in large, commercial pig production systems and requires strong observational skills and a working knowledge of animal husbandry and livestock systems operations. In recent years, many studies have explored the use of various technologies and sensors to assist animal caretakers in monitoring animal activity and behavior. Of these technologies, computer vision offers the most consistent promise as an effective aid in animal care, and yet, a systematic review of the state of application of this technology indicates that there are many significant barriers to its widespread adoption and successful utilization in commercial production system settings. One of the most important of these barriers is the recognition of the sources of errors from objective behavior labeling that are not measurable by current algorithm performance evaluations. Additionally, there is a significant disconnect between the remarkable advances in computer vision research interests and the integration of advances and practical needs being instituted by scientific experts working in commercial animal production partnerships. This lack of synergy between experts in the computer vision and animal health and production sectors means that existing and emerging datasets tend to have a very particular focus that cannot be easily pivoted or extended for use in other contexts, resulting in a generality versus particularity conundrum. This goal of this paper is to help catalogue and consider the major obstacles and impediments to the effective use of computer vision associated technologies in the swine industry by offering a systematic analysis of computer vision applications specific to commercial pig management by reviewing and summarizing the following: (i) the purpose and associated challenges of computer vision applications in pig behavior analysis; (ii) the use of computer vision algorithms and datasets for pig husbandry and management tasks; (iii) the process of dataset construction for computer vision algorithm development. In this appraisal, we outline common difficulties and challenges associated with each of these themes and suggest possible solutions. Finally, we highlight the opportunities for future research in computer vision applications that can build upon existing knowledge of pig management by extending our capability to interpret pig behaviors and thereby overcome the current barriers to applying computer vision technologies to pig production systems. In conclusion, we believe productive collaboration between animal-based scientists and computer-based scientists may accelerate animal behavior studies and lead the computer vision technologies to commercial applications in pig production facilities.

    Towards an intelligent approaches for cotton diseases detection: A review

    Manavalan R.
    14页
    查看更多>>摘要:? 2022 Elsevier B.V.Cotton is one of the leading fibers and plays a dominant role in the global industrial and agricultural economy. It is a primary material for the textile industry production. Various cotton leaf diseases include Bacteria blight, Foliar disease, Alternaria, etc. decrease the mass cotton production gain and quality. Hence, early diagnosis is demanded to avoid the ailments on cotton plants' leaves to increase productivity. The monitoring of cotton leaf disease and plants' health is complicated in farmers' naked eyes based on their own acquired knowledge and experience. It is expensive and impossible all-time for large plantation areas and leads to inaccurate control measurements of pesticides. The monitoring of the bugs and attacks in cotton plants is a sarcastic task for agriculture sustainability. Information on several diseases and syndrome can assist the farmers in determining the right pest control strategies to regulate diseases to improve cotton productivity. The study results betray that the available automated identification methods for cotton crop diseases are still in infancy. This review recognizes that automatic, economical, reliable, accurate, and rapid diagnosis systems are needed for cotton leaf disease discovery to increase production and quality. In this view, this paper exhibits an in-depth methodological review of various computational methods operated in different stages of plant-pathogen systems like image preprocessing, segmentation, feature extraction and selection, and classification to diagnosis the diseases for increasing cotton production. The issues behind the computational approaches of plant pathogens are addressed in-depth. The strengths and weaknesses of the state-of-art method in literature are highlighted. Further, the research issues also presented with valid future directions and further scope. Hence, novel, fully automatic computer-assisted systems are demanded to detect and classify numerous diseases in cotton plants.

    Recognition methods of threshing load conditions based on machine learning algorithms

    Ma Z.Jiang S.Li Y.Xu L....
    12页
    查看更多>>摘要:? 2022In order to identify the load conditions of threshing and separating device of combine harvester quickly and accurately, this experiment was conducted to collect vibration acceleration signals of the outer surface of threshing and separating device under different load conditions by field test in 2020 with the new rice variety Nanjing Jinggu as the research object. Firstly, based on the statistical analysis and signal analysis method, time domain, frequency domain, and time–frequency domain characteristics were extracted and fused into total domain characteristics to characterize the overall signal attributes of load conditions of the threshing and separation device so as to reduce the difficulty of data decision. Secondly, Principal Component Analysis (PCA) and Kernel Principal Component Analysis (KPCA) were used to remove the correlation and nonlinearity among the extracted characteristics, reduce the dimensionality of the characteristic vector and improve the accuracy of the diagnostic model. Finally, Support Vector Machine (SVM), Extreme Learning Machine (ELM) and Random Forest (RF) were used to diagnose the load conditions of the dimension reduction collection of total domains, and the accuracy rate and recognition time were used as evaluation indexes for the comparative analysis of model recognition. The results showed that the KPCA clustering separation effect is significant. RF has the highest recognition accuracy, which the accuracy of training set and prediction set are 100% and 98% respectively. The accuracy of ELM-KPCA model training set and prediction set is 100% and 90% respectively, and the analysis time is 6.206 s. This model accuracy is high, and the analysis time is the shortest, then ELM-KPCA model can be the best model for load conditions recognition of combine harvester.