屋顶花园的设计

屋顶花园的历史可以追溯到公元前2000年左右。我国自60年代起,才开始研究屋顶花园和屋顶绿化的建造技术。屋顶花园的规划设计,使屋顶的自然生态环境与城市总体生态环境融为一体,城市文明的延续与生活环境文化融合。屋顶花园的空间布局受到建筑固有平面的限制和建筑结构承重的制约,与露地造园相比,其设计既复杂又关系到相关工种的协同,建筑设计、建筑构造、建筑结构和水电等工种配合的协调是屋顶花园成败的关键。由此可见,屋顶花园的规划设计是一项难度大、限制多的园林规划设计项目。     

现代儿童玩具的安全性设计

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。     

Agreement and consensus in a Q-mode research design: an empirical comparison of measures,and an application

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     

梧州市河东防洪堤安全复核及工程加固设计

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。     

回转式电晕放电架的结构设计

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。     

析因实验设计与分析中的折扣系数及其应用——TAGUCHI方法研究

本文通过介绍在自动调节系统中常用的 TAGUCHI 最优校正法,引入折扣系数的概念;然后论述了在实验数据的方差分析中如何利用折扣系数的概念对最佳条件下响应的均值进行予测,并用两个例题分别说明折扣系数法在完全析因实验和分析因实验设计中的具体应用;最后是几点评论和补充说明。     

Estimation of the underlying structure of systematic risk with the use of principal component analysis and factor analysis

We present an improved methodology to estimate the underlying structure of systematic risk in the Mexican Stock Exchange with the use of Principal Component Analysis and Factor Analysis. We consider the estimation of risk factors in an Arbitrage Pricing Theory (APT) framework under a statistical approach, where the systematic risk factors are extracted directly from the observed returns on equities, and there are two differentiated stages, namely, the risk extraction and the risk attribution processes. Our empirical study focuses only on the former; it includes the testing of our models in two versions: returns and returns in excess of the riskless interest rate for weekly and daily databases, and a two-stage methodology for the econometric contrast. First, we extract the underlying systematic risk factors by way of both, the standard linear version of the Principal Component Analysis and the Maximum Likelihood Factor Analysis estimation. Then, we estimate simultaneously, for all the system of equations, the sensitivities to the systematic risk factors (betas) by weighted least squares. Finally, we test the pricing model with the use of an average cross-section methodology via ordinary least squares, corrected by heteroskedasticity and autocorrelation consistent covariances estimation. Our results show that although APT is very sensitive to the extraction technique utilized and to the number of components or factors retained, the evidence found partially supports the APT according to the methodology presented and the sample studied.     

Flexible work designs and employee well‐being: examining the effects of resources and demands

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.     

On third order rotatability

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.     

Optimality and efficiency of circular neighbor balanced designs for correlated observations

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.