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71.
This paper presents an autonomous robot capable of picking strawberries continuously in polytunnels. Robotic harvesting in cluttered and unstructured environment remains a challenge. A novel obstacle‐separation algorithm was proposed to enable the harvesting system to pick strawberries that are located in clusters. The algorithm uses the gripper to push aside surrounding leaves, strawberries, and other obstacles. We present the theoretical method to generate pushing paths based on the surrounding obstacles. In addition to manipulation, an improved vision system is more resilient to lighting variations, which was developed based on the modeling of color against light intensity. Further, a low‐cost dual‐arm system was developed with an optimized harvesting sequence that increases its efficiency and minimizes the risk of collision. Improvements were also made to the existing gripper to enable the robot to pick directly into a market punnet, thereby eliminating the need for repacking. During tests on a strawberry farm, the robots first‐attempt success rate for picking partially surrounded or isolated strawberries ranged from 50% to 97.1%, depending on the growth situations. Upon an additional attempt, the pick success rate increased to a range of 75–100%. In the field tests, the system was not able to pick a target that was entirely surrounded by obstacles. This failure was attributed to limitations in the vision system as well as insufficient dexterity in the grippers. However, the picking speed improved upon previous systems, taking just 6.1 s for manipulation operation in the one‐arm mode and 4.6 s in the two‐arm mode. 相似文献
72.
《Information & Management》2020,57(6):103244
Online reviews have a significant influence on consumers, and consequently firms are motivated to manipulate online reviews to promote their own products. This paper develops an analytical model to systematically explore the impact of online review manipulation on asymmetrical firms who sell substitutable search products in a competing market. Results show that a firm’s manipulation of online reviews is not necessary to hurt its competitor’s profit. In addition, if firms are free to choose whether to manipulate online reviews, both firms will always choose to manipulate online reviews. Moreover, there exists a prisoner’s dilemma in which online reviews are overmanipulated. 相似文献
73.
This paper explores the role of political connection on the overinvestment of Chinese energy firms. We argue that political connection can act as a “helping hand” that enables energy firms to obtain more government support to invest and a “grabbing hand” that forces politically connected energy firms to heavily overinvest for the promotion benefit of local politicians. Our analysis shows that overinvestment of an energy firm is positively affected by its political connection. In terms of the “helping hand” effects, we find that politically connected energy firms are more likely overinvest when they receive more government subsidy. In terms of the “grabbing hand” effects, we show that local politician is more likely to force energy firms to overinvest if the politician is approaching the 65-year-old promotion line. Although firms are less likely to overinvest during the economic downturn, local politician shapes the investment decision of energy firms through the “grabbing hand” effects. 相似文献
74.
Dr.-Ing. Jennifer C. Scheydt 《Beton- und Stahlbetonbau》2020,115(Z1):23-28
Suitability of geopolymers for the use in an agricultural environment An exchange between research institutions and the construction industry is an important prerequisite for practice-relevant research, which should not lack sufficient scientific depth. In this context, there has been a lively collaboration between HeidelbergCement AG and the Karlsruhe Institute of Technology (KIT) or the Materials Testing and Research Institute (MPA) Karlsruhe, respectively. An applicable tool to gain answers on relevant questions is the joint supervision of student theses. In addition to gaining knowledge, this offers the students the opportunity to gain deeper insights into a company. On the other hand, the company can possibly attract young people as new employee. In the following, the results of a jointly supervised master thesis on the suitability of geopolymers for the use in an agricultural environment [1] will be presented. These research results have already been reported elsewhere [2]. 相似文献
75.
76.
Recent European Directives promoted the development of biofuels, requesting mandatory limits to their emissions ot greenhouse gases (GHG). Second-generation biofuels based on lignocellulosic biomass are prime candidates but their GHG emissions are variable and uncertain. Agro-ecosystem modeling can capture them and the performance of biofuel feedstocks.This study aimed at optimizing feedstock supply for a bioethanol unit in France, from agricultural residues, annual and perennial crops. Their productivity and environmental impacts were modelled on a regional scale using geo-referenced data on soil properties, crop management, land-use and future weather data. Several supply scenarios were tested. Cereal straw was the most efficient feedstock but had a low availability, and only miscanthus could meet the bioethanol plant's demand. Sorghum combined poor yields and high GHG emissions compared by miscanthus and triticale. A mix of three biomass sources used less than 3% of the regional agricultural land while abating GHG emissions by 60%. 相似文献
77.
Tsai-De Chang Li-Nian Huang Yi-Jia Lin Zhong-Bin Wu Shang-Han Tsai Ying-Hong Lin 《International journal of molecular sciences》2022,23(21)
We developed an insulated isothermal PCR (iiPCR) method for the efficient and rapid detection of Fusarium oxysporum (Fo), which is a fungus that infects various hosts and causes severe crop losses. The Fo iiPCR method was sensitive enough to detect up to 100 copies of standard DNA template and 10 fg of Fo genomic DNA. In addition, it could directly detect 1 pg of mycelium and 10 spores of Fo without DNA extraction. Our study compared the performance of Fo iiPCR to that of three published in planta molecular detection methods—conventional PCR, SYBR green-based real-time PCR, and hydrolysis probe-based real-time PCR—in field detection of Fo. All diseased field samples yielded positive detection results with high reproducibility when subjected to an Fo iiPCR test combined with a rapid DNA extraction protocol compared to Fo iiPCR with an automated magnetic bead-based DNA extraction protocol. Intraday and interday assays were performed to ensure the stability of this new rapid detection method. The results of detection of Fo in diseased banana pseudostem samples demonstrated that this new rapid detection method was suitable for field diagnosis of Fusarium wilt and had high F1 scores for detection (the harmonic mean of precision and recall of detection) for all asymptomatic and symptomatic Fo-infected banana samples. In addition, banana samples at four growth stages (seedling, vegetative, flowering and fruiting, and harvesting) with mild symptoms also showed positive detection results. These results indicate that this new rapid detection method is a potentially efficient procedure for on-site detection of Fo. 相似文献
78.
文章主要分析了“互联网+”概念,阐述了我国农业发展中存在的问题,同时提出了相应改进对策,仅供参考. 相似文献
79.
虽然近年我国提倡机械化农业发展,但仍有部分农户未意识到农业机械化的重要性,使得农业机械化发展受到一定的限制.文章就北流市农机技术推广工作中存在的问题,提出结合网络推广,进行培训以及出台补贴制度并拓展市场的解决措施,以推进农机技术推广工作的顺利进行,促进农业增效农民增收. 相似文献
80.
文章分析了推广农业技术改革中在在的问题,探讨了创新推广农业技术的方法,并对创新推广农业额技术的发展趋势进行了研究. 相似文献