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Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A circular economy (CE) calls for the value of materials and products to be maintained and recovered through narrowing, closing, and slowing loops. However, there remain challenges in capturing value through reuse of components in refurbished and repaired products. In this paper, we provide an overview of the research and practice of harvesting spare parts from used and waste electrical and electronic equipment (white goods and consumer electronic products). Through a literature review and case studies of Norway, Sweden, and California, we provide an overview of drivers and barriers for spare part harvesting. Applying a stakeholder value mapping framework, we identify the key stakeholders involved in spare part harvesting and map the values captured, missed, and destroyed to identify opportunities for increased value retention. Finally, we suggest further refinements for policy to upscale spare part harvesting in light of CE goals and objectives. [ABSTRACT FROM AUTHOR]

During the harvesting of cut-stem vegetables, the structural parameters of cutters have an important influence on the harvesting effect. Structural parameters of stalks directly affect the cutting effect of the cutter. The thickness of the stalk xylem has a strong influence on the cutting stability and cutting surface effect of the cutter. In this paper, the effect of the broccoli stalk xylem on conventional toothless cutters was investigated using broccoli stalks as the cutting object. It was found that a thicker xylem leads to shear force fluctuations, which in turn affects the smooth operation of the cutting device. Taking locust mouthparts as the research object, a bionic multi-tooth cutting method is proposed in this paper to obtain the contour curve based on the locust upper jaw cutting tooth lobe. By establishing the regression equation, the contour curve of the cutting teeth is fitted accurately. The cutter edge is designed with the locust's maxillary incisive lobe as the bionic object. ANSYS software was used to simulate the cutting of a double disc cutter and broccoli stalk. The effect of each factor was analyzed by response-surface regression to determine the optimal cutter speed, machine forward speed, cutting inclination, blade overlap, and optimal cutting position. The cutting test is verified via broccoli stalks and a cutting test bench to further determine the cutting device operating parameters. The optimal operating parameters of the cutting device were 0.239 m/s forward speed, 30.974-degree cutting edge angle, 10.066 mm blade overlap, and 467.511 rpm. [ABSTRACT FROM AUTHOR]

Developing different robotic platforms for farm operations is vital to addressing the increasing world population. A harvesting robot significantly increases a farm's productivity while farmers focus on other relevant farm operations. From the literature, it could be summarized that the design concepts of the harvesting mechanisms were categorized as grasping and cutting, vacuum suction plucking systems, twisting and plucking mechanisms, and shaking and catching. Meanwhile, robotic system components include the mobile platform, manipulators, and end effectors, sensing and localization, and path planning and navigation. The robotic system must be cost-effective and safe. The findings of this research could contribute to the design process of developing a harvesting robot or developing a harvesting module that can be retrofitted to a commercially available mobile platform. This paper provides an overview of the most recent harvesting robots' different concept designs and system components. In particular, this paper will highlight different agricultural ground mobile platforms and their associated mechanical design, principles, challenges, and limitations to characterize the crop environment relevant to robotic harvesting and to formulate directions for future research and development for cotton harvesting platforms. [ABSTRACT FROM AUTHOR]

Continuing progress in machine learning (ML) has led to significant advancements in agricultural tasks. Due to its strong ability to extract high-dimensional features from fruit images, deep learning (DL) is widely used in fruit detection and automatic harvesting. Convolutional neural networks (CNN) in particular have demonstrated the ability to attain accuracy and speed levels comparable to those of humans in some fruit detection and automatic harvesting fields. This paper presents a comprehensive overview and review of fruit detection and recognition based on DL for automatic harvesting from 2018 up to now. We focus on the current challenges affecting fruit detection performance for automatic harvesting: the scarcity of high-quality fruit datasets, fruit detection of small targets, fruit detection in occluded and dense scenarios, fruit detection of multiple scales and multiple species, and lightweight fruit detection models. In response to these challenges, we propose feasible solutions and prospective future development trends. Future research should prioritize addressing these current challenges and improving the accuracy, speed, robustness, and generalization of fruit vision detection systems, while reducing the overall complexity and cost. This paper hopes to provide a reference for follow-up research in the field of fruit detection and recognition based on DL for automatic harvesting. [ABSTRACT FROM AUTHOR]

An accurate and robust keypoint detection method is vital for autonomous harvesting systems. This paper proposed a dome-type planted pumpkin autonomous harvesting framework with keypoint (grasping and cutting points) detection method using instance segmentation architecture. To address the overlapping problem in agricultural environment and improve the segmenting precision, we proposed a pumpkin fruit and stem instance segmentation architecture by fusing transformer and point rendering. A transformer network is utilized as the architecture backbone to achieve a higher segmentation precision and point rendering is applied so that finer masks can be acquired especially at the boundary of overlapping areas. In addition, our keypoint detection algorithm can model the relationships among the fruit and stem instances as well as estimate grasping and cutting keypoints. To validate the effectiveness of our method, we created a pumpkin image dataset with manually annotated labels. Based on the dataset, we have carried out plenty of experiments on instance segmentation and keypoint detection. Pumpkin fruit and stem instance segmentation results show that the proposed method reaches the mask mAP of 70.8% and box mAP of 72.0%, which brings 4.9% and 2.5% gains over the state-of-the-art instance segmentation methods such as Cascade Mask R-CNN. Ablation study proves the effectiveness of each improved module in the instance segmentation architecture. Keypoint estimation results indicate that our method has a promising application prospect in fruit picking tasks. [ABSTRACT FROM AUTHOR]

This paper describes an optimal harvesting policy for a wildebeest-lion prey-predator system in the Serengeti ecosystem with prey refuge. A Holling Type II prey-predator model with a nonlinear harvesting aspect was developed. Theoretical and numerical analyses were performed, and the dynamic behaviour of the system was found to be mathematically wellposed. Data on lion population density from the Serengeti ecosystem were used to fit the model using the maximum-likelihood method. The optimal harvesting policy was numerically determined using Pontryagin's maximum principle. Furthermore, the impact of prey refuge on the predator population was numerically evaluated. The results of this study highlight the importance of managing the lion population in the ecosystem, specifically in terms of harvesting criteria, to ensure that the threshold for wildebeest-lion coexistence is not exceeded. Based on the findings, this paper argues that the lion population should be given special attention in terms of managerial harvesting criteria so that the threshold for the wildebeest-lion coexistence in the ecosystem is not exceeded. [ABSTRACT FROM AUTHOR]

The holistic objective of producing 100% renewable generated electricity motivates the development of low-power and efficient domestic wind turbines. The wind turbine's efficiency can be maximized by operating it in a variable speed configuration, thus harvesting all the wind power. However, the harvesting process requires a two-stage conversion from AC to DC and from DC–DC or DC–AC. The paper aims to analyze the performance of the first stage of AC–DC rectification in terms of output voltage ripple and voltage regulation when the loading conditions vary abruptly. In addition, this work investigates the basic uncontrolled and controlled rectification methods for low-power wind turbines. The role of the output capacitance and its effect on output voltage ripples is illustrated. Finally, the paper highlights the design of a three-phase controlled rectifier using a simple yet effective firing angle control of a silicon-controlled rectifier (SCR) device. The delay caused due to the firing angle variations is reported in the simulations and experimental results to support the conclusion drawn from this study. [ABSTRACT FROM AUTHOR]

The paper presents studies and researches made on machines performance, which is one of the most important component of the economic performance of a farm. We made measurements for determination of work quality and energetic index for tractors, considering that tractors are the main energetic power used in modern agriculture anywhere, that is why the improving of the quality and energetic index of tractors and machines is very important. The aim of the research is to improve power performances and to increase the efficiency of tractors and agricultural machines. The productivity is one of the most significant characteristics of tractors and agricultural machines, especially of harvesting machines, which are the most important machines for harvesting cereals. We wanted to emphasize that designing and making these complex agricultural machines has much evolved in the last years, from the productivity point of view and from the design and interior comfort as well. [ABSTRACT FROM AUTHOR]

Researchers have shown that even an individual can produce the wisdom of the crowds, called "the wisdom of the inner crowd." However, the previous methods leave room for improvements in terms of efficacy and response time. This paper proposes a more efficient method, which required a short time, based on findings from cognitive and social psychology. The procedure is to ask participants to give two answers to the same question: first, their own estimate and, second, their estimate of public opinion. Experiments using this method showed that the averages of the two estimates were more accurate than the participants' first estimates. That is, the wisdom of the inner crowd elicited. In addition, we found that the method could be superior to other methods in terms of efficacy and convenience. Moreover, we identified the conditions where our method worked better. We further clarify the availability and limitations of using the wisdom of the inner crowd. Overall, this paper proposes an effective and short-time method for harvesting the wisdom of the inner crowd. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that grain loss in the harvest process accounts for a large loss in all aspects of the grain supply chain. This research extensively discusses the impact of farmland management scale on grain loss in the harvest process based on survey data on farmers' productivity in the Shandong and Hebei provinces of China. The findings revealed that the scale of farmland operation directly influenced the grain loss during harvest and that this effect is greatly reduced as the farmland operation scale increases. This study also constructed an intermediary model, investigated the influence mechanisms, and added agricultural capital as a variable in the harvest link. It was discovered that the scale of agricultural land management has an indirect effect on grain loss in the harvest link via the input of agricultural capital in the harvest link. The increase in agricultural capital investment in the harvest link considerably reduced this effect. In order to decrease grain losses during the harvest process, this paper suggests expanding the size of agricultural enterprises, developing new agricultural corporate organizations, and further playing the role of the rural land market. [ABSTRACT FROM AUTHOR]

High labor wages brought on by a shrinking agricultural labor force, as well as promises of increased crop yields and decreased labor requirements, have spurred the adoption of agricultural mechanization in Bangladesh. Due to these factors, the market for more complex agricultural machinery, such as rice transplanters and combine harvesters, is growing substantially in Bangladesh. As a result, a market has developed for agricultural workshops to manufacture spare parts within the local communities. However, the current manufacturing practices of local agricultural workshops limit their ability to produce high-quality parts that can compete with spare parts imported from China. This paper presents the analysis of the manufacturing processes used in the manufacturing of two key spare parts for the mechanization of planting and harvesting in Bangladesh: rice transplanter claws and combine harvester blades. The manufacturing processes proposed in this paper use machine tools and manufacturing processes that are ubiquitous in Bangladesh, such as grinders and drill presses. Additional manufacturing processes, such as blanking and forming with punch and die sets, are proposed as the methods for increasing product quality and reducing the manufacturing time required to produce complex geometries, such as those found on rice transplanter claws and combine harvester blades. The results from the experimental testing and the finite element simulations of the deformation processes indicate that local manufacturing of high-quality rice transplanter claws and combine harvester blades is viable with the proposed manufacturing processes. [ABSTRACT FROM AUTHOR]

Considering the problems of low soil fragmentation rates, high working resistance, and high energy consumption in the harvesting process of Cyperus esculentus in China, a method of Cyperus esculentus harvesting based on counter-rotation digging is proposed. The mechanism of interaction between the rotary tillage blade and Cyperus esculentus–soil is systematically investigated, and the vertical and horizontal disturbance performance of the positive and counter-rotating harvesting methods on soil and Cyperus esculentus is compared and analyzed. The results of the experiment showed that the intensity of soil and Cyperus esculentus disturbance by counter-rotation increased by 166.67% and 297.78%, respectively, and the effective disturbance time of soil and Cyperus esculentus increased by 133.33% compared to that of positive rotation. The working depth and rotation speed of the rotary tillage blade were the most significant for soil and Cyperus esculentus disturbance intensity. The working depth increased from 150 mm to 170 mm, and the soil disturbance intensity increased by 17.91% and 21.37% for positive and counter-rotating operation, respectively, and the rotation speed of the rotary tillage blade increased from 270 rpm to 330 rpm, and the soil disturbance intensity increased by 28.85% and 35.29%, respectively. Compared with the positive rotation operation, the Cyperus esculentus counter-rotation soil fragmentation rate increased by 4.09%, the Cyperus esculentus damage rate decreased by 10.69%, and the buried fruit rate decreased by 7.38%. This paper helps to understand the interaction mechanism between the rototiller and Cyperus esculentus–soil and lays a theoretical foundation for the subsequent design and optimization of the Cyperus esculentus digging device. [ABSTRACT FROM AUTHOR]

Fully utilizing the carbon sequestration potential of forests will help to further mitigate the aggravation of the greenhouse effect. In this paper, five typical tree species in Xiaoxing'anling are used as research objects. Based on the differences in the carbon dioxide sequestration capacity of different tree species at different growth cycles, a mathematical model of annual carbon sequestration benefits is established, the optimal annual cutting rates of five tree species are calculated, and the carbon sequestration capacity after ten years and economic benefits of the forest are predicted. The results showed that proper cutting of mature trees can increase annual carbon sequestration by 32% compared to no cutting. In addition, by comparing different forest management strategies, it was found that reasonable harvesting can bring higher economic benefits. We also confirmed that the increase in environmental temperature is one of the factors leading to the decrease in forest carbon sequestration capacity. The results of this paper can provide a theoretical basis for optimal forest management strategies. [ABSTRACT FROM AUTHOR]

Vibration harvesting is a promising method for walnut production owing to its low cost and high efficiency. However, current research focuses on simulation analysis and lacks a theoretical model explaining the walnuts' specific vibration response. This affects the design of the input vibration parameters during harvesting and thus reduces the harvesting efficiency. In this paper, a novel theoretical model of walnuts during vibration harvesting was established to analyze the vibration response, including the motion morphology (motion trajectory and dropping position) and detachment force. A field test was then carried out to verify the theoretical model. The theoretical and experimental results showed that the motion trajectory of the walnuts during vibration harvesting is similar to an ellipse, and the dropping position is at either of the two end points of the trajectory. The detachment force was found to be proportional to the vibration amplitude and the square of the vibration frequency theoretically. This paper provides a theoretical reference for designing the optimal input vibration parameters of a harvesting device to improve the harvesting rate of walnuts. [ABSTRACT FROM AUTHOR]

Non-integer orders for fractional differintegral based adaptive filtering are very useful for addressing the various levels of textural discrimination in any image. This paper addresses a novel contribution for image enhancement by harvesting the collective benefits of fractional-order differentiation (FOD) as well as fractional-order integration (FOI). A 2-D fractional-order (FO) "Differintegration" (FODI) based dual-operator is proposed for imparting "on-demand adaptive-filtering" through spatial masking for adaptive textural boosting along with contrast enhancement. In addition, FODI based adaptive filtering is also employed for improving the conventional Multiscale Retinex approach. Consequently, the second novel contribution in this paper is the proposed framework for Differintegration based Fractional-order Multi-scale Retinex (DFMSR) for effective reflectance channel computation. The proposed DFMSR module is readily compatible with other image pre-processing methods for effective suppression of airborne and/or illumination based visual imperfections. An optimal fractional-order two-dimensional adaptive filtering mechanism is proposed in this paper. The proposed model is highly modular. So, it can also be pipelined in parallel manner, along with any well-established state-of-the-art contrast enhancement approach. Total quality improvement for remotely sensed textural data is achieved in this work. Being highly modular, four different possible variants of proposed approach are also discussed in this draft, so that a generalized solution can be identified for overall quality improvement for diverse variety/domains of the visual data or images. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan University of Technology Natural Science Edition is the property of Henan University of Technology Journal Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

During the crop harvesting process, it is important to obtain the crop yield quickly, accurately and in real time to accelerate the development of smart agriculture. This paper investigated a denoising method applicable to the impact-type sunflower yield sensor signal under the influence of complex noise background in the pneumatic seed delivery structure for a sunflower combine harvester. A signal processing method combining complementary ensemble empirical mode decomposition (CEEMD) and wavelet threshold denoising (WTD) based on an adaptive decomposition capability was proposed by analyzing the non-smoothness of the signal with the impact-type sunflower yield sensor signal in sunflower fields. CEEMD was used to decompose the sunflower seed impact analog signal and field impact-type sunflower yield sensor signal adaptively, and the high frequency components were processed by WTD. Finally the de-noised signal was obtained by reconstruction. An evaluation objective function of the denoising ability of the algorithm based on signal-noise ratio, root mean square error, smoothness and waveform similarity indexes with different weights was also constructed. The results showed that the evaluation objective functions of the simulated and measured signals after denoising by the CEEMD-WTD method are 1.9719 and 4.5318, respectively, which are better than the single denoising methods of EMD (1.5096 and 4.0012), EEMD (1.8248 and 4.0724), CEEMD (1.9516 and 4.3384), and WTD (1.8737 and 4.5294). This method provides a new idea for signal denoising of the impact-type sunflower yield sensor installed in the pneumatic seed delivery structure, and further provides theoretical support and technical references for the development of sunflower high-precision yield measurements in smart agriculture. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ensuring a diverse range of grape varieties for fresh consumption, for as long as possible during a year, represents an equally important goal not only for producers but for traders as well. Our paper presents results regarding the evaluation of seven table grape varieties, six seeded varieties: 'Cardinal', 'Victoria', 'Muscat Hamburg', 'Alphonse Lavallée', 'Matilde', 'Black Magic' and one seedless variety, 'Attica', in specific pedo-climatic conditions from South-Western Romania. Observations, measurements and analyses were focused on: agrobiological, quantitative and qualitative characteristics (weight, length and width of bunch; berry weight, their length and width; grape yield, sugar content, titrable acidity, °Brix/acidity ratio). The assessment of vulnerability of table grape varieties at winter temperature conditions were also analysed. In the conditions of a low supply and high demand for table grapes at the end of July -middle of August in our country, the good productions and early harvesting of the 'Victoria', 'Black Magic' seeded varieties and 'Attica' seedless variety, represents a high market opportunity for Romanian table grape producers. [ABSTRACT FROM AUTHOR]

In Dobrogea the culture of the peach tree has had great perspectives even from the beginning due to the extremely favorable climate. The peach species loves warm weather and has always found good growing and harvesting conditions in the south-eastern part of Romania. In this period, 7 Romanian and foreign peach tree cultivars were studied at Research Station for Fruit Growing (RSFG) Constanta: 'Mimi', 'Catherine sel.1', 'Springcrest', 'Raluca', 'Cardinal' 'Filip' and 'Cora'. This paper presents the manner in which certain peach tree cultivars reacted to frost in the springtime of 2020, 2021 and 2022, as well as the effect of the hail on Jun 14th, 2022 on the peach production. The greatest losses caused by the frost were registered in the spring-time of 2020 as far as the fructiferous buds are concerned: 90% at 'Springcrest', 80% at 'Cardinal', 60% at 'Raluca' and 'Filip', 40% at 'Mimi', 'Cora' and 'Catherine sel.1', 20%. The losses caused by the hail on July 14th, 2022 affected the production of the 'Springcrest' cultivar by 80% and of the 'Cardinal' and 'Cora' by 70%. The climatic changes that have been registered throughout the past 10 years have negatively influenced the culture of the peach tree and the effects have been classified according to the cultivar and its biology, as well as to the topographic placement of the allotments. The studies that have been carried out, together with the obtained results demonstrate the importance of choosing the cultivar assortment taking into account the favorability of the area, as well as the importance of installing anti-hail nets when setting up fruit-growing plantations [ABSTRACT FROM AUTHOR]

This paper is devoted to the study of ecosystem based fisheries management. The model represents the interaction between prey and predator population with Holling II functional response consisting of different carrying capacities and constant intrinsic growth rates. We have considered the continuous harvesting of predator only. It is observed that if the intrinsic growth rate of predator population crosses a certain critical value, the system enters into Hopf bifurcation. Our observations indicate that tax, the management object in fisheries system play huge impacts on this system. The optimal harvesting policy is disposed by imposing a tax per unit of predator biomass. The optimal harvest strategy is determined using Pontryagin's maximum principle, which is subject to state equations and control limitations. The implications of tax are also examined. We have derived different bifurcations and global stability of the system. Finally, numerical simulations are used to back up the analytical results. [ABSTRACT FROM AUTHOR]

The experiment was conducted with a natural meadow of Agrostis capillaris-Festuca fallax type in the Rhodope Mountains (Smolyan region, Southern Bulgaria). The block-method in four repetitions and the harvesting plot area of 10 m2 with the following ways of use by years and undergrowths was used. The object of this study included annually (in 4 variants) and in the alternate years (in 3 variants) hay-grazing - use, grazing-hay - use, hay-grazing-grazing - use or only grazing-use of the particular regrowths in the different years. The harvesting in grazing-us? mode (grazing imitation) was accomplished in height of the grass stand 10-12 cm. The harvesting in hay-making mode was accomplished in flowering phenophase of the grasses. It was established that the studying different ways ?f harvesting given comparatively high dry matter yields. The following indicators were estimated: 1. Dry mass (DM) yield (in t/ha) - it was established by drying constant weight at 105 Celsius degree in muffle-oven of 0.5 kg green mass samples, taken immediately after cutting each trial plot and repetition; 2. Chemical composition of the absolutely dry matter included crude protein and crude fiber contents of the basic botanical groups (grasses and legumes) in the grass stand. They were determined by infrared spectroscopy on InfraAlyzer-400. For that purpose were done calibrations of 50 plant samples for each botanical group as every tenth sample was examined by analyzing after Weende-method. The crude fat content was determined after Soxletmethod, the crude ash - by weighing after dry calcination in a muffle-oven and the nitrogen-free extract substances (NFES) as an amount among the crude protein, the crude fiber, the crude fat and the crude ash. The crude protein and crude fiber of the grass biomass were in well-expressive opposite dependence. The others studied chemical indicators (crude fat, crude ash and NFES) had a less influence on the ways that were used for the grass stand. [ABSTRACT FROM AUTHOR]

This paper investigates the maximum principle for a nonlinear size structured model that describes the optimal management of the fish resources taking into account harvesting the fish and putting the fry. First, we show the existence of a unique non-negative solution of the system, and give a comparison principle. Next, we prove the existence of optimal policies by using maximizing sequence and Mazur's theorem in convex analysis. Then, we obtain necessary optimality conditions by using tangent-normal cones and adjoint system techniques. Finally, some examples and numerical results demonstrate the effectiveness of the theoretical results in our paper. [ABSTRACT FROM AUTHOR]

This paper provides radio frequency (RF) energy harvesting and coverage probability analysis using stochastic geometry in a two-hop communication network. In the first hop, terrestrial base stations (TBSs) transmit RF energy and data to the aerial base stations (ABSs) and in the second hop, ABSs forward the data to the user. Numerical results show that the energy harvesting and coverage probabilities can be maximized at almost the same altitude of the ABSs with respect to the TBSs height for low TBSs densities. However, as the density of the backhaul nodes and the energy harvesting sub-timeslot increases, energy harvesting probability improves while coverage probability monotonically decreases by increasing the ABSs height. [ABSTRACT FROM AUTHOR]

Pyruscommunis is a fruit that has its origins in China and Asia. It is a plant that is characterised by delicious, soft, fruits that are edible throughout the world. It is a known fact that this fruit grows well in temperate regions. In the USA, Pyruspyrifolia is another variety that's grown successfully. Some Asian pear varieties include Chinese Sand pear, Apple pear, Patharnakh and Gola pear, and these differ from each other in shape and colour. The purpose of this paper is to address pointers on harvesting Pyruscommunis L and P. pyrifolia in moderate to cold climates. [ABSTRACT FROM AUTHOR]

With the increasing scarcity of available forest for harvesting, there is a potential need for alternatives to wood fibers for pulp and paper production. Hemp is considered to be a good source of long and strong fibers. In this study, the effect of the harvesting age of hemp stems on their chemical composition and the biomass produced by the plants were studied. Hemp stems were harvested at ages of 30, 60, 90, and 120 days. Standard TAPPI procedures were used for chemical analyses of the stems. There was little variation observed in the percentage of the constituents such as lignin, hemicellulose, and α-cellulose with the plant growth. However, a very significant decrease was seen in the percentages of extractives, ash, and silica with plant growth. The rate of increase of biomass was higher in the first half of the growing period, i.e., from 30 to 60 days, compared to the second half, from 60 to 90 days. On the basis of the chemical constituents and the biomass produced, it is concluded that hemp grown for the pulp and paper industry should be harvested between 60 and 90 days for optimal results. [ABSTRACT FROM AUTHOR]

In this essay, we introduce a bioeconomic predator–prey model which incorporates the square root functional response and nonlinear prey harvesting. Due to the introduction of nonlinear prey harvesting, the model demonstrates intricate dynamic behaviors in the predator–prey plane. Economic profit serves as a bifurcation parameter for the system. The stability and Hopf bifurcation of the model are discussed through normal forms and bifurcation theory. These results reveal richer dynamic features of the bioeconomic predator–prey model which incorporates the square root functional response and nonlinear prey harvesting, and provides guidance for realistic harvesting. A feedback controller is introduced in this paper to move the system from instability to stability. Moreover, we discuss the biological implications and interpretations of the findings. Finally, the results are validated by numerical simulations. [ABSTRACT FROM AUTHOR]

• Saffron stigmas crop generates a large amount of biomass called by-product with high added value. • Saffron floral by-products (tepals, leaves, stamens, styles, spaths, and others) are rich in flavonoids, anthocyanins, carotenoids, and volatile compounds. • Chemical compounds contained in the saffron floral by-products have excellent antioxidant and anti-microbiological activities. • Bioactive compounds of saffron floral by-products are a great coloring and aromatic agents strongly used in industrial formulations. Saffron (Crocus Sativus L.), is the most expensive spice in the world, derived from the red filaments (stigmas) of a sterile triploid geophyte plant that belongs to the Iridaceae family. Saffron stigmas have been traditionally used in food and cosmetic products due to their coloring, flavoring, and aromatic aspects, attributed to their bioactive compounds, namely crocin, picrocrocin, and safranal. After harvesting saffron stigmas, a considerable amount of saffron floral parts so-called by-products are generated: petals, leaves, stamens, and others. Recent scientific studies have focused on cosmetic, therapeutic, and nutraceutical applications of not only saffron stigmas but also their several floral by-products. The chemical compounds contained in the whole saffron flower such as polyphenols, flavonoids, and anthocyanins, are endowed with excellent potentialities like antioxidant, and antimicrobial activities which makes them strongly used in food and cosmetic products. This paper aims to provide a systematic overview of specialized (secondary) metabolites applications of saffron stigmas as well as its by-products in various fields, also, the mechanisms of action of saffron bioactive compounds activities have been explained in this paper. [ABSTRACT FROM AUTHOR]

The study of harvesting mechanisms in predator-prey systems with an Allee effect on prey has always garnered significant attention. In this paper, the dynamics and harvesting strategies of a predator-prey system are investigated, where the prey is subject to the Allee effect. The positivity and boundedness of solutions, the existence and stability of equilibria are further studied. The existence of a Hopf bifurcation at the interior equilibrium point of the system is investigated and verified by numerical simulations. Furthermore, we investigate the maximum sustainable yield (MSY), maximum sustainable total yield (MSTY) and the optimal economic profit of the proposed system. We find that MSY can be attained through predator harvesting, while MSTY is observed when harvesting efforts are uniform across species. In these situations, the biological system maintains stability. Using the method of control parametrization, the optimal economic profit and harvesting strategy are obtained. The results show that the harvesting efforts can affect the stability of the system, resulting in several interesting biological phenomena. This research provides a theoretical basis for biological resource management. [ABSTRACT FROM AUTHOR]

Wireless sensors with low power consumption will play an important role in smart city applications. A power supply is required for the operation of these sensors. Considering the limited life of batteries and the need for regular maintenance, batteries are not an optimal solution for sensor networks with so many sensors. Radio Frequency Energy Harvesting (RFEH) and Wireless Power Transfer (WPT) are power supply methods that can easily supply power to low-power devices. Due to its ubiquitous nature, RF energy can be used as a source of power for wireless sensor nodes, wireless body area networks, wireless charging systems, RFID tags, and the Internet of Things. This paper presents the lifetime enhancement of the wireless sensor node based on the optimization of the SIW antenna for energy harvesting using the Particle Swarm Optimization (PSO) method. Here, an antenna and rectifier called a rectenna, needed by the harvesting node to convert power from free space transmitted by the base station into dc signals is designed, tested, and fabricated and the Direct Current (DC) output is used to power a low-power device. Compact structures and large arrays are possible with millimeter wave rectennas by Substrate Integrated Waveguide (SIW) technology is used since it has been advantageous to millimeter wave systems because it provides increased isolation and lower radiation leakage and losses. Also, we consider multi-objective multi-dimensional optimization for SIW antenna design, and geometric parameters are optimized to achieve better efficiency. The antenna is designed using HFSS, fabricated, and tested under ambient conditions and the results obtained show the percentage of lifetime of the sensor node improvement increases exponentially as the energy harvesting period increases. [ABSTRACT FROM AUTHOR]

Automatic detection of defects in mature litchi plays a vital role in the classification of fruit grades. The existing method mainly relies on manual, it is difficult to meet the needs of different varieties of litchi various types of commodity packaging, and there are problems such as low efficiency, high cost and poor quality of goods. To address the above problems, this paper proposes an improved You Only Look Once(YOLO)v7 algorithm for the automatic detection of post-harvest mature litchi epidermal defects. First, a dataset of litchi defects (black spot, fall off, crack) was constructed, in which the train and test sets had 4133 and 516; Next, A Simple Parameter-Free Attention(SimAM) mechanism is introduced into the original YOLOv7 backbone network, while GSconv is used in the neck instead of convolution, and the shallow network is used instead of the deep network for lateral linking, finally, the Mish function is used as the activation function. Experimental results show the precious and mAP of the original YOLOv7 are 87.66% and 88.98%, and those of the improved YOLOv7 are 91.56% and 93.42%, improvements of 3.9% and 4.44%. A good foundation is laid for the automated classification of ripe litchi after harvesting. [ABSTRACT FROM AUTHOR]

Apple orchards, as an important center of economic activity in forestry special crops, can achieve yield prediction and automated harvesting by detecting and locating apples. Small apples, occlusion, dim lighting at night, blurriness, cluttered backgrounds, and other complex scenes significantly affect the automatic harvesting and yield estimation of apples. To address these issues, this study proposes an apple detection algorithm, "YOLOv5-ACS (Apple in Complex Scenes)", based on YOLOv5s. Firstly, the space-to-depth-conv module is introduced to avoid information loss, and a squeeze-and-excitation block is added in C3 to learn more important information. Secondly, the context augmentation module is incorporated to enrich the context information of the feature pyramid network. By combining the shallow features of the backbone P2, the low-level features of the object are retained. Finally, the addition of the context aggregation block and CoordConv aggregates the spatial context pixel by pixel, perceives the spatial information of the feature map, and enhances the semantic information and global perceptual ability of the object. We conducted comparative tests in various complex scenarios and validated the robustness of YOLOv5-ACS. The method achieved 98.3% and 74.3% for mAP@0.5 and mAP@0.5:0.95, respectively, demonstrating excellent detection capabilities. This paper creates a complex scene dataset of apples on trees and designs an improved model, which can provide accurate recognition and positioning for automatic harvesting robots to improve production efficiency. [ABSTRACT FROM AUTHOR]

Promotion of research and development in advanced technology must be implemented in agriculture to increase production in the current challenging environment where the demand for manual farming is decreasing due to the unavailability of skilled labor, high cost, and shortage of labor. In the last two decades, the demand for fruit harvester technologies, i.e., mechanized harvesting, manned and unmanned aerial systems, and robotics, has increased. However, several industries are working on the development of industrial-scale production of advanced harvesting technologies at low cost, but to date, no commercial robotic arm has been developed for selective harvesting of valuable fruits and vegetables, especially within controlled strictures, i.e., greenhouse and hydroponic contexts. This research article focused on all the parameters that are responsible for the development of automated robotic arms. A broad review of the related research works from the past two decades (2000 to 2022) is discussed, including their limitations and performance. In this study, data are obtained from various sources depending on the topic and scope of the review. Some common sources of data for writing this review paper are peer-reviewed journals, book chapters, and conference proceedings from Google Scholar. The entire requirement for a fruit harvester contains a manipulator for mechanical movement, a vision system for localizing and recognizing fruit, and an end-effector for detachment purposes. Performance, in terms of harvesting time, harvesting accuracy, and detection efficiency of several developments, has been summarized in this work. It is observed that improvement in harvesting efficiency and custom design of end-effectors is the main area of interest for researchers. The harvesting efficiency of the system is increased by the implementation of optimal techniques in its vision system that can acquire low recognition error rates. [ABSTRACT FROM AUTHOR]

The problem of optimal forest rotation in a nonstationary environment can, in general, not be solved analytically. Even qualitatively characterizing how the solution changes over time is only possible in some special cases. In this paper, we consider an approximation of the true solution to the nonstationary problem. We derive an approximate harvesting rule by solving a sequence of stationary problems that assume the growth conditions at that point in time will prevail indefinitely. Each such problem can be solved using the classic Faustmann rule. We numerically compare this approximate solution to the true solution, both in terms of the harvesting rule and the resulting expected profits, for a wide range of scenarios. We find that the harvesting rules are very similar (mostly <1 $\lt 1$% difference) and the profit losses associated with following the approximate rule are very small (less than 0.3%). Recommendations For Resource Managers: We consider a forest‐rotation decision when climate change, or technology, change the growth of trees. Recommendations for forest owners or managers may include: Taking climate change and technology into account is important for forest managers' decision of when to harvest.Predicting precisely how climate change will change future forest growth is probably not important for the rotation decision.But observing the changes in forest growth without too much delay is most likely very important.Our results pertain to the forest‐rotation decision and do not take into account, for example, thinning, changing tree species, or selling the land for other use. [ABSTRACT FROM AUTHOR]

The course of weather conditions during the growing season, but also beyond it, decides the economics of hop cultivation every year. Ongoing climate changes manifested by more frequent occurrence of compound hot and dry waves affect hop cultivation not only in the Czech Republic, but in the entire region of Central Europe. The paper evaluates the harvest results (yields, alpha acid content) of four Czech hop varieties in the period 2019-2022 with a focus on the weather diametrically opposed vintages 2021 and 2022 on a specific agricultural farm in the Žatec (Saaz) hop-growing region. While the 2021 vintage was rich in precipitation in the decisive vegetation phase, the 2022 vintage was very dry and hot. The age of the plants significantly influenced the alpha acid content of the varieties Saaz, Sládek and Premiant independently of the vintage. Young growths of the Saaz variety contained at least 60% rel. more alpha acids than older growths (more than 5 years old), while the increase in the Sládek variety was 30-40% rel. and in the Premiant variety 20-25% rel. In the case of the variety Agnus, the age of the plants did not have a demonstrable effect on the content of alpha acids. In 2021 the yields of all varieties were negatively affected by the calamitous occurrence of downy mildew. In 2022, the rainfall deficit was so large that it could not be fully compensated even by the maximum use of drip irrigation. Of the evaluated varieties, the Agnus variety coped best with the different weather conditions of the assessed vintages. This shows that the cultivation of climate resistant varieties is one of the promising but time-consuming ways to face the expected climate changes. Other options include regular renewal of hop growths, consistent regionalization, i.e. planting hop in locations that are suitable for the given variety and efficient use of irrigation systems. [ABSTRACT FROM AUTHOR]

In this paper, piece-wise smooth predator prey Filippov system to describe the role of refuge to prey and additional food to predators is explored. Logistic growth of prey and Holling type II predation is considered. Selective proportional harvesting of predators is included. Refuge is provided to a fraction of preys when their density is below a threshold value. This reduces the food availability for predators. To compensate this, additional food is provided to predators. The dynamics on the boundary is computed using the Filippov regularization method. The stability and existence of different equilibrium states of the independent smooth subsystems are analyzed. The role of quality of additional food with respect to prey in the characterization of the equilibrium points as regular or virtual equilibrium points for the Filippov system is investigated. It is verified that if only refuge is provided to prey with no additional food to predators then both the interior equilibrium state will never be regular simultaneously for the Filippov system. It is observed from the sliding mode dynamics that there is no escaping region. It is proved that both refuge to prey and additional food to predators enhances the sliding region on the boundary. The analysis of boundary equilibrium points, tangent points and pseudoequilibrium points on the boundary is carried out. The role of effort on harvesting on the expansion or shrinking of the limit cycle is elaborated numerically. Boundary bifurcation for the interior equilibrium state of the subsystems is demonstrated. Numerical simulation is used to elaborate the dynamics of Filippov system. [ABSTRACT FROM AUTHOR]

Purpose: This article demonstrates the possibility of energy harvesting by mistuned pendulums with torsional coupling. Two pendulums of different lengths with coils and magnets at the pivots are used as electromagnetic harvesters. The ambient energy source to the system is considered in the form of harmonic base excitations. Torsional coupling is achieved by connecting the pendulums with a torsional spring. The non-linearity of the underlying dynamics arises due to mechanical coupling and forcing amplitude. Numerical results are presented to analyze the performance of the pendulum energy harvester under different torsional coupling values. Method: The mathematical model of the electro-mechanical system with torsionally coupled pendulums under harmonic excitation is developed. The mistuning is introduced by two pendulums with different lengths l1 and l2. The coupling between them is achieved by a torsional spring of stiffness kc. These pendulums are connected to the shafts of the electromagnetic generators with a magnet attached to the pendulum as a rotor and coil as stator. Current i is generated due to electromagnetic induction whenever pendulum oscillates. The numerical and harmonic balance method analysis were carried out. Runge-Kutta integration was used for numerical analysis. The analysis was carried out to determine the effect of coupling, length and resistive coefficient. The bifurcation diagram and Poincare plots were used for dynamic analysis and cross recurrence plots for analysis of relations between pendulum harvesters. Results: The effect of coupling on harvester performance was carried out, the variation of maximum power and frequency band with coupling can be categorized into 3 zones. The ranges for Zone-I, II and III of maximum power are [0-0.059], [0.06-0.11] and above 0.11 respectively. In Zone-I total power and the total band are dominating over pendulum-1 and pendulum-2. In Zone-II, the performance of pendulum-2 is comparable with the total performance. In contrast, the performance of pendulum-1 is low. Saturation of maximum power and bandwidth can be observed in zone-III. Uncoupled pendulum-1 and 2 exhibits a periodic oscillation. A low amplitude quasi-periodic response of pendulum-1 and high amplitude quasiperiodic response of pendulum-2 can be observed for coupling of β = 0.04. Both pendulums exhibit high amplitude chaotic response at β = 0.07. The introduction of coupling induced nonlinearity in both pendulums. the amplitude and velocity also increased due to the quasi-periodicity and chaos induced in pendulums due to the coupling and better energy harvesting capabilities can be expected. The harmonic balance analysis indicates that there is a possibility of obtaining a high amplitude current at lower frequencies provided proper initial conditions are chosen. Conclusion: A twin electromagnetic pendulum energy harvester with torsional coupling is analyzed in order to optimize the efficient energy harvesting and study the energy harvester dynamics. The paper categorized the three distinct zones based on the coupling ratio β and length ratio α2. One can select parameters from these zones based on need. Zones-II and III are the most promising zones. If one wants to harvest broader energy Zone-II is preferable with harvesting only from the energy harvester with a low resonant frequency which in turn saves material cost. To harvest peak power one can, select Zone-III and harvest from both energy harvesters. The performance in the respective zones can be further enhanced by using optimal initial conditions to obtain high energy orbits at lower frequencies. The probability of obtaining high energy orbits decreases with an increase in the coupling ratio. The effect synchronization with coupling on energy harvesting plays an important role form magnitude and bandwidth point of view. The analytical results obtained by the Harmonic Balance Method are in good agreement with numerical results. [ABSTRACT FROM AUTHOR]

Forest biomass harvest has the potential to provide feedstocks for energy production to offset fossil fuel consumption. However, concerns have been raised regarding the ecological sustainability of removing additional biomass from forests, in particular the impacts on biodiversity. In this paper, we used a suite of ground-dwelling arthropod taxa (ground beetles, spiders, and rove beetles) to measure community compositional changes along a gradient of biomass removal treatments 7 years postharvest, and compared against reference. Based on multivariate regression trees, changes in species composition reflected the intensity gradient of the biomass removal treatments or stand attributes associated with the level of forest floor disturbance across all arthropod groups. For each arthropod group, changes in composition were defined primarily by reductions or loss of abundant forest associated species and increases in the number and abundance of species associated with more xeric conditions and increased disturbance intensity. There were no differences between full-tree and tree-length treatments. Overall, results indicated a strong arthropod response to the removal of overstory, forest floor disturbance, and reductions in understory cover mostly resulting from the glyphosate applications. Arthropod recovery would benefit from overstory retention, reduction in forest floor disturbance, and judicious use of glyphosate. [ABSTRACT FROM AUTHOR]

Seas, marine, and coastal regions are integral and essential parts of our ecosystem. Many scientific approaches have been taken to ensure the sustainable use of marine resources. Artificial intelligence (AI) plays a vital role in harvesting resources so that the system regenerates itself for the long term. This paper develops a two-input and two-output fuzzy logic-based model to predict the fisheries' remaining biomass after harvesting and maintaining a high revenue level in the Bangladesh Sundarbans region. Fishing & tourism are taken as input parameters, and revenue & biomass are taken as output parameters. A total of 20 rules (IF-THEN type) have been generated in the fuzzy rule editor of Fuzzy Inference System (FIS), considering all possible combinations between input–output parameters. The data which we obtained from the real ecosystem exactly corresponds to the results that we got from our proposed model. Our fuzzy logic model yields valid predictions of the remaining biomass level without compromising profit, only by controlling the harvesting and tourist entry. [ABSTRACT FROM AUTHOR]

Cassava (Manihot esculenta Crantz) is a major tuber crop worldwide, but its mechanized harvesting is inefficient. The digging–pulling cassava harvester is the primary development direction of the cassava harvester. However, the harvester clamping–pulling mechanism cannot automatically adjust its position relative to the stalks in forward movement, which results in clamping stalks with a large off-center distance difficulty, causing large harvest losses. Thus, solving the device's clamping location problem is the key to loss reduction in the harvester. To this end, this paper proposes a real-time detection method for field stalks based on YOLOv4. First, K-means clustering is applied to improve the consistency of cassava stalk detection boxes. Next, the improved YOLOv4 network's backbone is replaced with MobileNetV2 + CA, resulting in the KMC-YOLO network. Then, the proposed model's validity is demonstrated using ablation studies and comparison tests. Finally, the improved network is embedded into the NVIDIA Jetson AGX Xavier, and the model is accelerated using TensorRT, before conducting field trials. The results indicate that the KMC-YOLO achieves average precision (AP) values of 98.2%, with detection speeds of 33.6 fps. The model size is reduced by 53.08% compared with the original YOLOv4 model. The detection speed after TensorRT acceleration is 39.3 fps, which is 83.64% faster than before acceleration. Field experiments show that the embedded model detects more than 95% of the time at all three harvest illumination levels. This research contributes significantly to the development of cassava harvesters with intelligent harvesting operations. [ABSTRACT FROM AUTHOR]

Hemerocallis citrina Baroni with different maturity levels has different uses for food and medicine and has different economic benefits and sales value. However, the growth speed of Hemerocallis citrina Baroni is fast, the harvesting cycle is short, and the maturity identification is completely dependent on experience, so the harvesting efficiency is low, the dependence on manual labor is large, and the identification standard is not uniform. In this paper, we propose a GCB YOLOv7 Hemerocallis citrina Baroni maturity detection method based on a lightweight neural network and attention mechanism. First, lightweight Ghost convolution is introduced to reduce the difficulty of feature extraction and decrease the number of computations and parameters of the model. Second, between the feature extraction backbone network and the feature fusion network, the CBAM mechanism is added to perform the feature extraction independently in the channel and spatial dimensions, which improves the tendency of the feature extraction and enhances the expressive ability of the model. Last, in the feature fusion network, Bi FPN is used instead of the concatenate feature fusion method, which increases the information fusion channels while decreasing the number of edge nodes and realizing cross-channel information fusion. The experimental results show that the improved GCB YOLOv7 algorithm reduces the number of parameters and floating-point operations by about 2.03 million and 7.3 G, respectively. The training time is reduced by about 0.122 h, and the model volume is compressed from 74.8 M to 70.8 M. In addition, the average precision is improved from 91.3% to 92.2%, mAP@0.5 and mAP@0.5:0.95 are improved by about 1.38% and 0.20%, respectively, and the detection efficiency reaches 10 ms/frame, which meets the real-time performance requirements. It can be seen that the improved GCB YOLOv7 algorithm is not only lightweight but also effectively improves detection precision. [ABSTRACT FROM AUTHOR]

Jordan is facing significant challenges related to water scarcity, including overexploitation of groundwater, increasing demand, and wasteful practices. Despite efforts to manage water resources, inadequate planning has resulted in ongoing water security concerns and deteriorating water quantity and quality. To address water stress, Jordan has implemented measures such as desalination, dam construction, and water conservation initiatives. However, water stress remains high, necessitating a comprehensive strategy that includes short-term demand-side interventions and long-term supply-side reforms. Financial and governance challenges hinder the implementation of these measures, requiring private investment and coordination among stakeholders. This paper provides a comprehensive review of Jordan's water resources, analyzing current trends, challenges, and opportunities. The aim is to offer insight into the current situation and propose sustainable management approaches. The findings will be valuable for policymakers, researchers, and stakeholders working towards addressing Jordan's complex water challenges and securing a sustainable water future for its citizens. [ABSTRACT FROM AUTHOR]