机器视觉技术在农业机械上的应用

随着计算机和图像处理技术的发展,机器视觉技术的研究和应用已扩展到农业工程领域,并取得了许多重要研究成果.介绍了该技术在播种、喷雾和移栽等方面的研究和应用情况,指出了机器视觉技术在我国农业机械检测和自动导航中具有广阔的应用前景.     

Objective wrinkle evaluation system of fabrics based on 2D FFT

Drying is one of the main processes in the course of washing laundry. During the washing and drying processes in an electric or gas dryer, wrinkles can form on garments. To minimize the wrinkles on the clothes after the processes, a reliable and objective method of assessment of wrinkles should be devised. Wrinkles have been assessed with visual inspection methods by human observers, which were defined by AHAM or AATCC. This method cannot provide objective data for wrinkles because people judge the same things differently according to their own subjective criteria. Thus, this paper is focused on the development of an objective and quantitative system for grading fabric wrinkles based on the 2D-FFT. The system developed in this study has been proven to be objective and quantitative in comparison with the existing test methods.     

不同水分条件下水稻籽粒形态及其与粒重的关系

运用机器视觉检测技术, 以普通杂交稻汕优63和超级杂交稻国稻6号为材料, 在幼穗分化开始至分化后30 d分别设置不同的控水处理, 通过水分仪结合称重法控制土壤含水量, 研究了稻穗及穗上不同部位籽粒的形态性状, 并分析各性状与粒重的关系。结果表明：水稻的籽粒面积、长度及千粒重对水分反应较明显, 水分亏缺对籽粒面积和粒重的影响引起比粒重(单位籽粒面积的重量)变化, 长宽比对水分也有一定反应, 宽度对水分的响应因品种而异。籽粒形态性状、产量及其构成因素均随水分亏缺的加重而有不同程度下降, 穗生长发育全阶段的控水处理影响最大, 其次是中期的重度和中度控水处理以及前期、后期的重度控水处理, 各时段控水对不同部位籽粒形态的影响与穗分化发育的顺序历期基本吻合。除粒宽与其他形态性状之间呈极显著或显著负相关以外, 其余各籽粒形态性状之间均呈极显著正相关。籽粒面积、长度及长宽比与千粒重之间存在极显著或显著的相关关系, 可以作为水稻抗旱性鉴定有效的籽粒形态指标。     

基于机器视觉的工业机器人智能分拣系统设计研究

随着我国工业发展脚步的不断加快,机器人在工业智能化中发挥的作用日益突出,将其应用到机械零件分拣工作中,可以利用机器人的智能化特点,代替传统模式下的人工操作.基于此,本文主要从机器视觉技术出发,探讨基于机器视觉的工业机器人智能分拣系统设计,以此来为日后工业生产效率及质量的提升提供参考.     

Effect of blindfolding on centre of pressure variables in healthy horses during quiet standing

In a standing horse the centre of pressure (COP), measured as the resultant vertical ground reaction force (GRF) of all supporting limbs, is adjusted in response to visual, vestibular and proprioceptive information. Stabilographic analysis measures balance by tracking COP movements in the horizontal plane. Loss of visual input affects stability of balance in people and has clinical implications in that instability inherent in some neurological diseases increases with the eyes closed. The objectives of this study were to evaluate the visual contribution to postural stability in horses. The hypothesis was that the magnitude and variability of postural sway variables increases when visual input is removed. Vertical GRFs were measured using two synchronized force plates and COP movements were tracked in 20 horses as they stood without visible movements of the hooves, head or neck. Three trials of 60 s duration were recorded under sighted and blindfolded conditions. Stabilographic variables (craniocaudal and mediolateral COP amplitudes, velocities and mean power frequencies and their within-trial variabilities) were calculated and compared using univariate analysis of variance.Compared with the sighted condition, blindfolding increased the magnitude and the within-trial variability of craniocaudal and mediolateral COP amplitudes and mediolateral COP velocity. The findings indicated that loss of visual input had more effect on the measured COP variables in the time domain (amplitudes, velocities) than in the frequency domain (mean power frequency). The effects of blindfolding on postural stability should be further investigated as part of a diagnostic approach to the evaluation of balance in horses with neurological impairment.     

A criteria and indicator prognosis for sustainable forest management assessments: Concepts and optional policy baskets for the high forest zone in Ghana

ABSTRACT

This article establishes principles conveyed by criteria and indicators as a useful tool for measuring progress made toward sustainable forest management (SFM). Pedagogically, the conceptual construction raises questions on the following topics: (a) the various management practices and policies that exist in the high forest zone, (b) how criteria and indicators for assessments are selected, and (c) how progress made toward SFM is measured. Performance scores are established for indicators identified within the three sectors (forest ecosystems, forest communities, and the economy) for sustainability assessment. Measuring progress toward SFM operations are quantitatively performed with estimated maximum and minimum thresholds levels at which resource-use would be sustained using the Measure of Forest Resource-Use Sustainability Scale (MoFRUSS). The outcome of the measurement operations, as depicted by MoFRUSS, reveals the actual extent to which stakeholder’s initiatives toward sustainable forest management has progressed and in which direction it is moving. It also offers optional policy baskets for resource management interventions from which the socio-eco economic bundle is recommended if the forestry sector of Ghana’s Vision 2020 (sustainable development) is to be achieved with improved societal well-being, improved environmental health and vitality, and improved economic growth and development.     

Sensors for product characterization and quality of specialty crops—A review

This review covers developments in non-invasive techniques for quality analysis and inspection of specialty crops, mainly fresh fruits and vegetables, over the past decade up to the year 2010. Presented and discussed in this review are advanced sensing technologies including computer vision, spectroscopy, X-rays, magnetic resonance, mechanical contact, chemical sensing, wireless sensor networks and radio-frequency identification sensors. The current status of different sensing systems is described in the context of commercial application. The review also discusses future research needs and potentials of these sensing technologies. Emphases are placed on those technologies that have been proven effective or have shown great potential for agro-food applications. Despite significant progress in the development of non-invasive techniques for quality assessment of fruits and vegetables, the pace for adoption of these technologies by the specialty crop industry has been slow.     

智能车辆自主导航神经网络控制器设计

针对自主设计、制造的智能车辆,提出了设计新的神经网络控制器来实现对车辆导航路径的自主跟踪控制。分析了神经网络导向控制器的设计方法,选择了神经网络导向控制器的输入、输出变量,并建立了神经网络导向控制器的结构。在此基础上,采用人工驾车采集的数据对控制器进行了训练。完成了计算机仿真和实际路径跟踪控制试验,试验结果表明该神经网络控制器能够很好地实现对导航路径的自主跟踪控制。     

The teleost pseudobranch: a role for preconditioning of ocular blood supply?

The physiological relevance of the teleost pseudobranch as a remnant of a reduced gill arch is still unclear. Numerous hypotheses have been proposed regarding its physiological role, but direct confirmatory evidence is lacking. The close relationship by serial blood flow arrangement with the fish eye’s choroid rete has sparked the idea that pseudobranchial preconditioning of blood pH may facilitate initiation of the Root effect and thus support the establishment of high oxygen tensions for retinal diffusive supply. This idea was critically tested by studies on isolated pseudobranchs in situ (Oncorhynchus mykiss), perfused with RBC/Ringer or RBC/plasma suspensions of widely varied composition (pH 7.4–8.2). Detailed analysis of inflowing as compared to effluent perfusates indicated normal aerobic metabolism expressed by a rise in Pco₂ (+0.39 ± 0.13 mmHg ), an oxygen utilization of 25% and a high oxygen consumption of ∼400 nmol g⁻¹ min⁻¹. Upon passage of the pseudobranch, pH (corrected for Haldane effect) was only slightly acidified (−0.03 to −0.10), [HCO₃ ⁻] and [lactate] were slightly enhanced (+0.51 mmol l⁻¹ or 0.13 mmol l⁻¹, respectively). In order to test for yet unknown plasma components involved in pseudobranch function, a second series of experiments was conducted using RBC-suspensions in fresh plasma instead of Ringer, with results closely resembling those of the RBC/Ringer series. Lacking any physiologically significant correlation with the level of perfusate pH, the obtained data indicate pseudobranchial basic metabolic activity rather than pH regulatory characteristics. Also the observed absolute changes in pH are negligible in terms of pH regulation towards the Root-threshold. Accordingly, the present experiments as well as plausibility evaluation of mechanisms do not support the idea of blood pH pre-adjustment prior to entry into the choroid rete structure of the teleost eye to facilitate the Root-mediated oxygen release.