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31.
现代儿童玩具的安全性设计   总被引:1,自引:0,他引:1  
随着人们生活水平的不断提高,玩具已经由从前的奢侈品变成如今大多数孩子的必需品。但是由于儿童没有识别、防范和躲避危险的能力,现代一些玩具产品的质量、安全性直接关系到儿童的身体健康和生命安全。在玩具的开发设计中,就必须考虑儿童玩具的性质和特点,保证儿童在玩的过程中既安全又快乐。  相似文献   
32.
Subject of this paper is the analysis of consensus within small groups of respondents, based on a proportionally large number of variables. The target group is researchers who are interested in Q-mode research. Measures of agreement are compared, and an application from a recent project is presented. Cohen’s κ is the preferable measure, Krippendorff’s α is an alternative, which is based on a different concept of expected disagreement. At group level, along with κ and α for multiple raters, additional measures are r wg, intraclass correlation, and κ SC. Predictions about level differences between groups can be assessed by a t-test and θ  相似文献   
33.
阐述了对广西梧州市河东防洪堤进行安全复核的缘由,介绍了几种安全复核的方法和工程加固设计方案,并结合现场实际情况论证河东防洪堤安全复核的结论,证明对其所采取的工程措施是有效的。  相似文献   
34.
电晕处理机是一种应用非常广泛的塑料薄膜表面处理设备,放电架是其主要组成部分。针对放电架结构的特点,介绍了一种放电架总体结构的设计方法,并对其主要组成部件的结构设计进行了详细的论述。这种放电架采用回转式结构,利用气缸推动回转组件运转,提高了放膜的方便性和安全性。  相似文献   
35.
Advances in communication technology continue to expand the possibilities for redesigning work environments to allow for temporal and spatial flexibility. Although flexible work designs (FWDs) are typically launched with high expectations, recent research shows that FWDs also pose challenges to employees and can even impede employee well‐being. Based on the Job Demands–Resources model, we argue that FWDs offer both advantages (FWD‐related resources) and challenges (FWD‐related demands) to employee well‐being. The results (n = 999) show that FWDs are related to employee well‐being through several positive and one negative pathways. FWDs are positively associated with employee well‐being through enhanced work/life balance, autonomy, and effective communication and negatively associated with employee well‐being through increased interruptions. Thus, we introduce a framework that reveals the underlying positive and negative mechanisms in the relationship between FWDs and employee well‐being.  相似文献   
36.
Third order rotatability of experimental designs, moment matrices and information surfaces is investigated, using a Kronecker power representation. This representation complicates the model but greatly simplifies the theoretical development, and throws light on difficulties experienced in some previous work. Third order rotatability is shown to be characterized by the finitely many transformations consisting of permutations and a bi-axial 45 degree rotation, and the space of rotatable third order symmetric matrices is shown to be of dimension 20, independent of the number of factorsm. A general Moore-Penrose inverse of a third order rotatable moment matrix is provided, leading to the information surface, and the corresponding optimality results are discussed. After a brief literature review, extensions to higher order models, the connections with tensor representations of classic matrix groups, and the evaluation of a general dimension formula, are all explored.  相似文献   
37.
The purpose of this paper is to apply the Kunert and Martins (2000b) method for finding optimal designs into the case of dependence. Using this method we study optimality of circular neighbor balanced designs at distances 1 and 2 under the one-dimensional interference model with errors correlated according to a circular autoregressive process. We determine the efficiency of binary designs for specified values of correlation coefficient, for which these designs are not optimal.Research partially supported by the KBN Grant Number 5 P03A 041 21.  相似文献   
38.
In this paper we present a new method for constructing multi-level supersaturated designs with n rows, m columns and the equal occurrence property. We investigate the existence of multi-level supersaturated designs using a single generator vector and its k-cyclic permutations as rows. We find the conditions needed, in order this vector to generate a balanced supersaturated design. These conditions are simplified for the case of three level supersaturated designs. By using the proposed method three level supersaturated designs are constructed and explored. Moreover, many new, optimal and near optimal, multi-level supersaturated designs are provided as well.  相似文献   
39.
Orthogonal main-effect plans for two and three factors in small blocks are obtained from the dual of adjusted orthogonal row-column designs. The method for constructing efficient plans is presented, and a relationship between the average efficiency factors of the row-column design and the corresponding main effects is given for the two-factor case. Orthogonal Main Effect.  相似文献   
40.
A general method for construction of E(s 2)-optimal, two-level supersaturated designs (SSDs) with the equal occurrence property, from supplementary difference sets is introduced. It is proved that SSDs constructed in this way are E(s 2)-optimal. Comparisons are made with previous works and it is shown that the proposed method gives promising results for the construction of E(s 2)-optimal large SSDs.  相似文献   
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