首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 171 毫秒
1.
The farm vehicle combined switch(VCS)being multifunctional and irregular,the evaluations for them have been difficult problems,which has gotten VCS manufacturers and their users into troubles.So some of their users have still been evaluated VCS with the hand touch-feeling method.In order to make the evaluation more scientific,an integrated test facility,which have three kinds of bionic robot hands(twist,push and draw-out type),and its evaluation mothed were developed for VCS.Meanwhile,some tests,which consisted of subjective tests(experts hand touch-feeling)and objective machine tests,were made to examine this technique.The aim of the tests was to grade the same kind of VCS products among three different manufacturers.By comprehensive analysis,a conclusion can be obtained that there is a significant correlation between the subjective expert method and objective machine one in the VCS evaluation.With regard to machine one,the contributions of the parameters such as the shifting force,inflection force and effective shifting time to the evaluation of VCS are major.This machine evaluation technique can be used to describe and grade the quality of VCS products,and ultimately examine their material,process and assembly,which can be a useful method for authorities who make decisions during production,sourcing/buying as well as design of VCS.  相似文献   

2.
Spade methods to visually evaluate soil structural quality (Sq) are simple, quick, cheap and can be used by farmers, gardeners, consultants and the scientific community. However, European and Brazilian users of one such method, viz. visual evaluation of soil structure (VESS) which is a development of the Peerlkamp test, have been concerned about its subjectivity. The method of soil slice break‐up and operator influence on scores have been questioned. Thus, our aim was to make soil scoring by the VESS technique more objective and thus to revise the scoring guide. We compared scoring with normal breaking up of the soil slice by hand with scoring after breaking up the slice by dropping (drop shatter) to make the soil break‐up more operator independent. After slice break‐up, aggregates were split by hand and their internal porosity was evaluated to develop the use of visible porosity as an aid to scoring. This proved inconclusive on its own, so a method of reducing larger aggregates to 1.5–2.0 cm core fragments and describing their shape and porosity was developed to score soil Sq. Breaking up a spadeful of soil by hand or by dropping resulted in the same Sq score. The method of reducing aggregates and evaluation of their shape improved VESS, particularly in the middle range of soil quality and the revised chart is shown. VESS was sensitive to changes in Sq in layers within the profile and its use for diagnosing Sq in different layers allows targeted soil improvement by tillage.  相似文献   

3.
基于深度集成学习的青梅品级智能反馈认知方法   总被引:3,自引:1,他引:2  
针对传统机器判定水果品级的开环认知模式存在特征空间和分类准则一旦建立不再更新的缺陷,模仿人由整体到局部反复推敲比对的思维信息交互认知模式,探索了一种具有认知结果熵测度指标约束的青梅品质智能反馈认知方法。首先,在有限论域不确定条件下从信息论角度建立具有信息完备性评价指标的非结构化多层面动态特征表征的青梅品级认知智能决策信息系统模型。其次,基于架构自适应的卷积神经网络(adaptive structure convolutional neural networks,ASCNNs)和集成随机权向量函数连接网络分类器(random vector functional-link net,RVFL),建立青梅图像由整体到局部有明确品级特征表征映射关系的特征空间数据结构与分类准则。再次,基于广义误差和广义熵理论,建立青梅图像认知结果的熵函数形式测度评价指标。最后,建立基于不确定过程认知结果性能测度指标约束的动态反馈认知智能运行机制。针对1 008幅青梅图像的平均识别率为98.15%,表明该文方法有效地增强了特征空间的泛化能力以及分类器的鲁棒性。该研究可为基于可见光的青梅品级快速准确机器认知提供参考。  相似文献   

4.
Pome fruit growers and crop consultants have expressed concerns about the seasonal release performance of commercial codling moth mating disruption dispenser products. Because of these concerns, we developed a laboratory flow-through volatile collection system (VCS) for measuring the volatile release of the codling moth sex pheromone, codlemone, from commercially available hand-applied dispensers. Under controlled air-flow and temperature conditions, the released vapor was trapped onto a polyurethane foam adsorbent followed by solvent extraction, solvent reduction, and GC/MS determination. Method recovery and breakthrough validations were performed to demonstrate system reliability before determining codlemone release from commercial dispensers field-aged over 140 days. The volatile collection was carried out in a consistent manner among five dispenser types most commonly used by growers, so that direct comparison of performance could be made. The comparison showed differences in the amount of pheromone released and in the patterns of release throughout the season between dispenser types. The variation in release performance demonstrates the need for routine evaluation of commercially marketed mating disruption dispensers. We believe that the simple and cost-effective volatile collection system can assist pheromone dispenser manufacturers in determining seasonal dispenser performance before new products are introduced into the commercial market and in rapidly verifying dispenser release when field-aged dispenser efficacy is in question.  相似文献   

5.
针对机械系统设计方案各评价技术指标间模糊且相互关联的特点,研究了机械系统方案设计的决策问题,该文在综合考虑从优隶属度和灰色关联的基础上,提出了改进灰色关联模糊决策方法,从整体角度寻求复杂系统的最优设计方案。运用模糊数学隶属函数理论,对原始数据进行无量纲化和归一化处理,为防止技术指标信息在评价过程中丢失,建立了技术指标权重集及灰色关联系数矩阵,通过综合评价模型,实现了机械产品总体设计方案的模糊优选。最后,以YF27-315型薄板冲压液压机设计为例,验证该模型可以有效减少评价过程中的主观因素干扰,能全面、客观地对机械产品设计方案作出决策。  相似文献   

6.
基于博弈论的可拓评价方法在灌区运行状况评价中的应用   总被引:9,自引:4,他引:5  
针对目前灌区运行状况评价方法的不足,引入改进的物元可拓评价方法.运用博弈论的综合赋权法将主观权重和客观权重相结合,克服了传统的可拓评价方法中单纯依靠指标数据赋权而忽略了指标自身对评价的重要性等弊端.在等级评定中,通过计算等级变量特征值得到等级所属程度.运用上述方法对东港灌区运行状况进行评价研究,结果与实际情况吻合良好,表明将改进的可拓评价方法运用到灌区的综合评价中是合理可行的.  相似文献   

7.
In this study, a liquid chromatography (LC)/turbo ion spray (TIS)-mass spectrometry (MS) method was developed to examine the chromatography or "fingerprint profile" of seven Cimicifuga herbs and six Cimicifuga racemosa (black cohosh) commercial products. Triterpene glycoside components were selected as chemical markers for analysis because they have appeared as a major compound group in Cimicifuga species. LC/MS chromatograms unveiled the patterns of C. racemosa, Cimicifuga dahurica, Cimicifuga foetida, Cimicifuga heracleifolia, Cimicifuga japonica, Cimicifuga acerina, and Cimicifuga simplex, which are very different from each other. 23-Epi-26-deoxyactein was found only in C. racemosa, C. dahurica, and C. foetida. A highly selective and sensitive LC/MS/MS method for quantitative analysis of 23-epi-26-deoxyactein with detection levels up to 2.5 ng in these samples was also developed and was applied to six commercial C. racemosa products. C. racemosa and its six commercial products contained about 6-15% of 23-epi-26-deoxyactein in total triterpene glycosides. On the other hand, the estimated amount of total triterpene glycosides in other commercial products was either greater or lesser than what the manufacturers claimed. The technique and LC/MS profiles generated in this study provide a reliable and reproducible method that can be readily utilized for botanical identification of Cimicifuga plants, for examination and validation of its commercial products, and for "chemical" quality control in the manufacture of black cohosh products.  相似文献   

8.
拖拉机双离合器自动变速器换挡品质评价指标   总被引:1,自引:3,他引:1  
针对双离合器自动变速器拖拉机在田间高负载作业工况下进行换挡时,原换挡品质评价指标不能充分考察对性能的影响,提出了变速器输出转矩传递系数和变速器输出转矩2个评价指标。归纳了奇数挡和偶数挡离合器接合与分离时序对换挡品质影响规律,建立了拖拉机DCT换挡动力学模型和换挡品质仿真模型。以东方红1804拖拉机为研究对象,对其犁耕工况进行了仿真分析,结果表明:当离合器油压上升滞后时间分别为0、0.1及0.2 s时,对应的变速器最小输出转矩传递系数分别为0.42、0.36及0.12,变速器最小输出转矩分别为2 257、1 932及725 N·m,产生的动载荷逐渐增大,拖拉机动力性变差;提出的2个换挡品质评价指标可较好地对换挡过程中产生的动载荷和拖拉机动力性进行评价,对原换挡品质评价指标进行了补充,完善了拖拉机DCT换挡品质评价体系。该研究为拖拉机双离合器自动变速器换挡控制策略制定提供了理论依据。  相似文献   

9.
综合集成赋权法在灌区节水改造效益评价中的应用   总被引:6,自引:3,他引:3  
为了合理确定大型灌区节水改造后评估指标权重,从而对节水改造效益进行科学评价,应用基于单位化约束条件的综合集成赋权法进行指标权重确定计算,并将该方法应用于陕西省关中大型灌区节水改造项目效益评价中。应用结果表明,与单纯的主观赋权法和客观赋权法以及目前其他已有的综合集成赋权法相比,基于单位化约束条件的综合集成赋权法能够兼顾主客观影响因素,且原理科学、计算过程简便,有较好的实际应用价值。  相似文献   

10.
土地资源评价方法及评价因素权重的确定探析   总被引:13,自引:0,他引:13       下载免费PDF全文
综述了目前土地资源评价方法和评价系数权重的确定研究成果,评价了主观赋权法(德尔菲、AHP法)和客观赋权法(主成分分析法、因子分析法、灰色关联法和熵值法)的优、缺点,并认为运用主观赋权法掺杂了决策者的主观随意性,而运用客观赋权法却缺乏决策者的意愿。指出主、客观信息综合集成的新方法是土地资源评价方法及评价因素权重确定的新途径。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号