烟用包装材料交验抽样方法研究

本文以国家抽样检验标准为依据，结合烟草行业自身特点，对制定烟用包装材料交验抽样方法的原则、依据和方法进行了较为深入的探讨和研究，以卷烟条与盒包装纸为例，设计了基于三个不同国家抽样标准下的三种交验抽样方案，通过对三种方案分别进行分析评价，给出了各自的使用条件和使用方法，对提升烟草行业烟用包装材料交验抽样工作的规范化和科学化水平具有一定的促进作用。     

抽样及其在我国商品计量中的应用

本文讨论了抽样的意义，并对抽样和抽样超几何分布进行了分析研究，最后对我国商品计量抽样方案进行了计算，得出了商品计量合格率的数据表。     

展览会观众抽样调查理论研究

对展览会观众数据进行统计时,如果不能详细采集所有观众的数据,则必须采取抽样调查的方式,就会引入抽样准确度的问题。为了获得更可靠的结论,需要扩大抽样的样本量,从而增加抽样调查工作的成本与复杂度。本文通过统计学原理对此问题进行定量分析,从而在抽样准确度与抽样工作成本之间找出一个合适的平衡点。     

结构体系可靠度分析中的最小方差抽样

本文研究了并联结构体系可靠度分析中以失效概率估计值方差最小为条件的重要抽样问题。由于直接对抽样样本平均值和标准差进行优选比较困难，因而本文首先建立了三个定理，据此并通过数例分析给出正态抽样样本平均值和标准差的建议取值范围。分析和实际模拟表明，在以正态分布进行抽样的前提下，合理选取抽样样本平均值和标准差，可使抽样效率进一步提高。     

食品质量监督检验抽样中的问题及策略

抽样检验是指随机抽取一部产品代表其整体接受检验的一项程序,由检测机构按照国家标准对样品进行检测并作出判断。抽样工作的合规性以及工作质量将会对检测结果有直接影响,同时也关系到被检测企业的利益。在食品质量监督中,抽样检查是食品质量检查的重中之重,本文旨在结合笔者自身工作经验,从抽样的几个关键环节和国家相关规定出发,剖析食品抽样中需要注意的事项,希望能够对提高食品安全抽样检验工作质量有一定帮助。     

如何做好质量监督抽样检验工作

本文针对质量监督抽样工作进行探讨,分析抽样检验工作中存在问题,并提出相关建议,希望更能够为质量监督抽样检验工作的发展提供一点理论支持。     

确定抽样检验性质的重要性

了解、估计、判定产品总体质量水平的高低，往往采用抽样检验的方法，以样品的质量情况来评价或确定产品总体的质量水平。然而，由于各部门的工作内容不同，抽样检验的目的也不同。例如，有的抽样检验是为了监督产品质量水平。其性质为监督抽样检验；有的是为了控制产品质量水平，其性质为验收抽样检验；有的是为了判别产品质量水平，其性质为交易抽样检验。     

光栅调制和积分抽样

通过对光学图象调制和光电成像系统的抽样过程的研究，得出两条结论：１）光学图象的调制函数和抽样函数都具有周期重复特性，调制图象和抽样图象的频谱分布服从抽样定理；２）用谐频光栅进行图象调制和用点阵对图象抽样都可以精确恢复原图象，而阵列光栅的图象调制和光电成象系统中的积分抽样对图象恢复具有不同的效应。     

探析产品质量监督中抽样检验标准的使用

本文以抽样检验标准的概括性叙述作为切入点,从多个角度对产品质量监督中抽样检验标准的程序以及有效使用展开了综合分析,并进行了关于抽样检验标准的创新研究,以期利用抽样检验标准来更好的展开产品质量监督工作,提高检验质量。     

强化食品抽样检验推动食品安全深度监管

食品安全关乎到每个人的健康,加强对食品安全的监管工作是每个食品安全检测人员的首要任务。而面对庞大食物消费品市场,对食品安全的检测工作难以全面地针对每一个食品进行检验。因此便催生出对食品的抽样检验的方法。本文将对食品抽样检验工作的难点进行探讨,从而提出相关的加强食品安全检测的具体做法,促进食品安全检测工作的进程。     

采样抖动研究进展述评

回顾了采样抖动的研究进展, 主要针对两种基本采样抖动: 随机抖动和非随机抖动. 每一种抖动均从三种不同的技术形式进行介绍: 实时采样; 等效采样; 非均匀采样. 每一种技术形式均按照三个研究方向予以归纳展示: 采样抖动的影响; 采样抖动的测量与评估; 采样抖动的修正与补偿. 总结归纳了采样抖动研究所涉及的主要理论、方法、技术, 使用的主要信号波形, 采样抖动研究的基本问题, 研究目标和最终目的. 总结归纳出了抖动与噪声的根本区别在于其影响依赖于信号波形的时变性的本质特征.     

Effect of sampling method on the level of styrene monomer migrated from polystyrene packaging material

Different types of polystyrene packaging material were tested for styrene monomer migration into corn oil using three sampling methods: immersion sampling, vapour phase sampling and utilization of sampling cells. For high-impact-grade polystyrene, immersion sampling resulted in the highest level of migrated styrene monomer. Vapour phase sampling was of considerable interest, because migration was only slightly lower than with immersion sampling. Sampling cells gave the lowest levels of styrene monomer in oil. However, when clear crystal polystyrene was tested, little difference was found between the three sampling methods.     

Influence of timing jitter on quadrature charge sampling

The influence of timing jitter on quadrature charge sampling for a direct conversion receiver has been evaluated. In contrast to voltage sampling, the charge sampling mixer integrates the signal current instead of tracking the signal voltage. The charge sampling mixer has been applied to RF direct sampling in wireless receivers. The influence of timing jitter on charge sampling has been analysed in some literatures. However, in wireless receivers, quadrature sampling is required in order to demodulate I-phase and Q-phase signals. Different from charge sampling, timing jitter causes crosstalk between these signals. The influence of timing jitter on quadrature sampling is investigated.     

一种实验用高温高尘气体灰分同时取样装置的研制

针对高温高尘环境中气体和灰分取样所面临的取样管融化烧断问题、堵塞问题和卤化碱凝结问题,提出一种实验用髙温高尘气体灰分同时取样装置。该装置由取样探头和过滤取样器两部分组成,其中采用三层水冷套管的取样探头解决取样管融化烧断问题,采用外部过滤取样器解决高尘导致的堵塞问题,采用烟气温度控制方法解决卤化碱凝结问题。     

A Novel Multiple Dependent State Sampling Plan Based on Time Truncated Life Tests Using Mean Lifetime

The design of a new adaptive version of the multiple dependent state (AMDS) sampling plan is presented based on the time truncated life test under the Weibull distribution. We achieved the proposed sampling plan by applying the concept of the double sampling plan and existing multiple dependent state sampling plans. A warning sign for acceptance number was proposed to increase the probability of current lot acceptance. The optimal plan parameters were determined simultaneously with nonlinear optimization problems under the producer’s risk and consumer’s risk. A simulation study was presented to support the proposed sampling plan. A comparison between the proposed and existing sampling plans, namely multiple dependent state (MDS) sampling plans and a modified multiple dependent state (MMDS) sampling plan, was considered under the average sampling number and operating characteristic curve values. In addition, the use of two real datasets demonstrated the practicality and usefulness of the proposed sampling plan. The results indicated that the proposed plan is more flexible and efficient in terms of the average sample number compared to the existing MDS and MMDS sampling plans.     

抽样引起的测量不确定度评定

若测量值定义为抽样目标中的分析物浓度,那么与抽样相关的不确定性必然导致最终测量结果的不确定度。抽样不确定度主要来源于抽样目标的不均匀性、抽样方案不明确、抽样和样品制备过程中引入的交叉污染、分析物损失等。以欧洲分析化学会的指南为基础,介绍了抽样不确定度评定的经验方法,该方法将测量不确定度来源区分为抽样过程和分析过程中的随机效应与系统效应。通过实例说明了如何通过重复实验和方差分析来量化抽样和分析过程中的随机效应,从而评估抽样和样品制备所引入的不确定度。     

产品质量检验的分层抽样法研究

分层抽样作为现代统计方法中最常用的抽样组织形式,已在实践中受到主管广泛重视,它比纯随机抽样具有更高的抽样精度。本文在介绍分层抽样法的基础上将该方法应用于A企业的B产品的抽样检验中,并取得了较好的效果。产品被滞留在生产车间内的比例由20％批／班次减少为平均5％批／班次,生产秩序明显好转。     

配网重点物资采购抽检方案研究

针对现行配网物资采购抽检制度中存在的不同批量的产品事实上宽严程度不一致的问题,基于常用的MIL-STD-1916抽样标准,提出一种计数调整型的配网重点物资抽检方案。该抽检方案结合电网的抽检实际,在考虑科学性的基础上,兼顾电网抽检相关文件中规定的重点物资抽样检验4个“百分之百”的要求和(n|0)要求,且不加大现有抽检工作量。研究成果可以直接应用于配网物资采购抽检实际工作中。     

Multiple deferred state sampling inspection

Multiple deferred state sampling is on attribute inspection procedure in which the decision criterion for each lot dictates one of three decisions: (1) accept the lot; (2) reject the lot; or (3) conditionally accept or reject the lot based on the disposition of future related lots. It is intended to supplement existing sampling procedures such as chain sampling, dependent stage sampling, exponential smoothed sampling, and fixed deferred state sampling.     

A new sampling scheme for developing metamodels with the zeros of Chebyshev polynomials

The accuracy of metamodelling is determined by both the sampling and approximation. This article proposes a new sampling method based on the zeros of Chebyshev polynomials to capture the sampling information effectively. First, the zeros of one-dimensional Chebyshev polynomials are applied to construct Chebyshev tensor product (CTP) sampling, and the CTP is then used to construct high-order multi-dimensional metamodels using the ‘hypercube’ polynomials. Secondly, the CTP sampling is further enhanced to develop Chebyshev collocation method (CCM) sampling, to construct the ‘simplex’ polynomials. The samples of CCM are randomly and directly chosen from the CTP samples. Two widely studied sampling methods, namely the Smolyak sparse grid and Hammersley, are used to demonstrate the effectiveness of the proposed sampling method. Several numerical examples are utilized to validate the approximation accuracy of the proposed metamodel under different dimensions.