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铜含量分析仪广泛应用于发电厂除盐水、蒸汽冷凝水、炉水及化工、制药、化纤、半导体行业高纯水测量。本文对不确定度的分量进行综合考虑,找到了产生不确定度的主要分量,评定了铜含量分析仪测量结果示值误差的不确定度。 相似文献
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饮料中糖精钠含量是衡量饮料质量安全的重要卫生指标之一,文章研究用高效液相色谱法检测饮料中糖精钠含量测量结果的不确定度.以高效液相色谱法检测饮料中糖精钠含量,根据数学模型从随机误差引入的不确定度分量、系统误差引起的不确定度分量进行了计算.高效液相色谱法检测饮料中糖精钠含量测量结果的不确定度为0.008g/kg. 相似文献
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依据JJF1059-1999测量不确定度评定与表示技术规范分析了ARL3460型直读光谱仪测量中低合金钢中锰元素含量的不确定度分量主要来源,对测量结果的不确定度进行了评定。 相似文献
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对离子选择电极法测定固体废物浸出液中氟化物含量进行了不确定度的评定。通过建立被测量的测量模型,识别对测量结果有明显影响的不确定度的来源,定量评定各输入量的标准不确定度,合成得到测定结果的相对扩展不确定度。 相似文献
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对铁含量分析不确定度的分量进行综合考虑,找到了产生不确定度的主要分量,评定了铁含量分析仪测量结果示值误差的不确定度. 相似文献
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目的：分析用石墨炉原子吸收光谱法测定阿胶中铬的测量不确定度。方法：应用测量不确定度评定理论,结合实际的试验方法,建立数学模型,确定和计算测定过程各不确定度分量,分析总的相对不确定度。结果：阿胶中铬含量为1．1mg/kg,取包含因子k=2,其扩展不确定度为0．2mg／kg,最终测定阿胶中铬含量为（1．1±0．2）mg／kg;同时对影响测定结果的不确定度的各部分因素进行了量化。结论：影响测量结果的不确定度主要因素是回收率,标准曲线拟合引入的误差以及重复测定标准偏差其次,标准物质及其稀释过程引入的不确定度、环境条件等对测量结果的不确定度影响较小。 相似文献
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《内蒙古科技与经济》2016,(12)
利用BS224S型电子天平对煤中全水分进行10次测量,测定其煤中全水分含量,并对测量的不确定度进行评估,通过建立数学模型,分别对由电子天平的分辨率引入的不确定度、称量不准引入的不确定度及测量重复性引入的不确定度进行分析,最终确定了煤中全水分测定的不确定度主要影响因素是天平的重复性测量。 相似文献
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Sampled-data control for time-delay systems 总被引：1，自引：0，他引：1
The sampled-data systems are hybrid ones involving continuous time and discrete time signals, which makes the traditional analysis and synthesis methodologies of time-delay systems unable to be directly used in the cases of hybrid systems with time-delay. The primary disadvantages of current design techniques of sampled-data control are their inabilities to deal effectively with time-delay and the model uncertainty. In this paper, we generalized the analysis methodology of time-delay systems to that of the hybrid systems with time-delay and uncertainty, which developed a design procedure of sampled-data control for time-delay systems. Asymptotic stability of the time-delay hybrid systems was developed. The time-delay dependent robust sampled-data control for the time-varying delay of an uncertain linear system was then discussed. The results were described as linear matrix inequalities, which can be solved using newly released LMITool. 相似文献
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This research focuses specifically on uncertainty and information seeking in a digital environment. In this research we argue that different types of uncertainty are associated with the information seeking process and that, with the proliferation of new and different search tools, sources and channels, uncertainty, positive/desirable or negative/undesirable, continues to be a significant factor in the search process. Users may feel uncertain at any stage of the information search and retrieval process and uncertainty may remain even after completion of the process resulting in what may be called persistent uncertainty. An online questionnaire was used to collect data from users in the higher education sector. There were three parts to the questionnaire focusing on: information seeking activities, information seeking problems, and access to specific information channels or sources. Quantitative analysis was carried out on the data collected through the online questionnaire. A total of 668 responses were returned from the chosen user categories of academic staff, research staff and research students. This research has shown that there are some information seeking activities and information seeking problems that are the most common causes of uncertainty among significant number of users from different disciplines, age, gender, ICT skills, etc. This is also the case with respect to access to and use of specific information sources/channels, although the degrees of uncertainty in relation are relatively small. Possible implications of this study and further research issues are indicated. 相似文献
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基于高技术产业集群的环境不确定性、社会网络与知识外溢关系的实证研究 总被引：1，自引：0，他引：1
本文构建了基于高技术产业集群的环境不确定性、社会网络及知识外溢之间的关系模型,在理论分析的基础上,提出相关假设。使用结构方程模型方法,利用AMOS4．0软件对长春高新区软件产业集群中136家软件企业的问卷调研数据进行实证分析,实证结果表明,环境不确定性影响集群社会网络的构建和发展,而集群社会网络对知识外溢具有重要的促进作用。 相似文献
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为了用尽可能小的蒙特卡罗模拟样本来反映模型模拟结果中的不确定性,把拉丁超几何体采样引入地统计随机模拟的LU分解算法.首先把拉丁超几何体采样与普通随机采样在LU分解算法中的表现进行比较,然后把基于拉丁超几何体采样的LU分解法应用于空间直观森林景观模型LANDIS的模拟.结果表明,与普通随机采样相比,拉丁超几何体采样能捕获更多的不确定性,特别是在蒙特卡罗模拟次数较少时.LANDIS模型的模拟结果表明,由地统计学随机模拟所引入的不确定性在象元尺度上随模拟时间增加而增加,但是在景观尺度上并没有受很大影响.这表明由地统计学随机模拟所参数化的LANDIS模型可用于大时空尺度森林景观变化的预测 相似文献
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《Information processing & management》2020,57(6):102304
The way that users provide feedback on items regarding their satisfaction varies among systems: in some systems, only explicit ratings can be entered; in other systems textual reviews are accepted; and in some systems, both feedback types are accommodated. Recommender systems can readily exploit explicit ratings in the rating prediction and recommendation formulation process, however textual reviews -which in the context of many social networks are in abundance and significantly outnumber numeric ratings- need to be converted to numeric ratings. While numerous approaches exist that calculate a user's rating based on the respective textual review, all such approaches may introduce errors, in the sense that the process of rating calculation based on textual reviews involves an uncertainty level, due to the characteristics of the human language, and therefore the calculated ratings may not accurately reflect the actual ratings that the corresponding user would enter. In this work (1) we examine the features of textual reviews, which affect the reliability of the review-to-rating conversion procedure, (2) we compute a confidence level for each rating, which reflects the uncertainty level for each conversion process, (3) we exploit this metric both in the users’ similarity computation and in the prediction formulation phases in recommender systems, by presenting a novel rating prediction algorithm and (4) we validate the accuracy of the presented algorithm in terms of (i) rating prediction accuracy, using widely-used recommender systems datasets and (ii) recommendations generated for social network user satisfaction and precision, where textual reviews are abundant. 相似文献
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本文基于176份中国制造企业的调研数据,研究环境不确定性、供应链整合战略以及企业绩效之间的关系。实证研究结果表明:(1)环境不确定性显著影响供应链整合战略实施。相对于需求不确定和技术不确定的促进作用,供应不确定显著抑制供应链整合的实施。(2)三种供应链整合战略对企业绩效影响不同。内部整合显著提升企业绩效,客户整合仅显著提升运作绩效,而供应商整合对于企业绩效无显著影响。本文丰富和完善了供应链整合的研究,对管理实践也具有一定的指导意义。 相似文献
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利用沿海地区481名留任员工的调查数据拟合假设关系模型,研究发现:两种裁员不确定感都是消极影响员工心理调控能力的重要因素,但它们对员工心理调控能力的影响机制却并不一致;员工自我调控对员工绩效的正向影响要远大于自我效能;通过多群因果分析和联合T检验发现,组织干预感知对裁员不确定感、心理调控和员工绩效三者之间的关系起调节作用。 相似文献
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公平是所有社会交换和经济交换关系所必须考虑的基础元素,它对个体在交换关系中的合作行为有着直接而显著的影响,这在创业企业家—创业投资人关系中同样适用。引入了公平启发理论和不确定管理理论,探讨了以下问题:在投资后管理阶段,创业投资人的公平感知如何影响着他的合作行为;创业投资人的不确定感知以及他对双边关系所做的专用性投资如何影响着公平感知—合作行为之间的关系;以及如何理解创业投资人的投资后管理行为。 相似文献
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本文提出了一个反映环境不确定性、企业文化强度、企业学习强度和企业绩效关系的过程模型。采用来自企业层面的数据，应用结构等式模型对本文的过程模型进行了实证检验。研究发现：过程模型得到了验证。其中环境不确定性和企业文化强度、企业学习强度显著正相关，企业学习强度、企业文化强度对企业绩效均有显著的正向作用，其中企业学习强度的正向作用更大。 相似文献
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Antonio Davila 《Research Policy》2003,32(8):1397-1420
This study investigates the use of variable compensation to motivate new product development managers and its impact upon the performance of new product development projects. Using data from 56 projects, the paper examines how technology-intensive firms compensate their product development managers. The study finds a positive and significant relationship between the use of short-term economic incentives and project performance; however, the slope of this relationship is not linear and its intensity (slope) decreases as the percentage of variable compensation increases; furthermore, the relationship is contingent on the level of project uncertainty. The results also indicate that higher project uncertainty is associated with a lower level of variable compensation. Moreover, organizational structure, through its effect upon the allocation of uncertainty among organizational participants, also affects the level of variable compensation. 相似文献