COMPLEX MODE SUPERPOSITION ALGORITHM FOR SEISMIC RESPONSES OF NON-CLASSICALLY DAMPED LINEAR MDOF SYSTEM

This paper deals with a complex mode superposition method for the seismic responses of general multiple degrees of freedom (MDOF) discrete system with complex eigenvectors and eigenvalues. A delicate general solution, completely in real value form, for calculat-ing seismic time history response of the MDOF system which cannot be uncoupled by normal modes, is deduced based on the algorithms of the complex superposition method. This solution comprises of two parts which are in relation to the Duhamel integration to sine and cosine function respectively. The related term of the Duhamel integration to sine function is actually the displacement response of the oscillator with corresponding modal frequency and the damping ratio. The other can be transferred into a combina-tion of the displacement and velocity responses of the same oscillator. In order to meet the practical needs of seismic design based on code design spectra for various kinds of structures equipped by viscous dampers, the complex complete quadratic combination (CCQC) method is deduced following similar procedures such as the well-known CQC method, in which a new modal velocity correlation coefficient, together with a new modal displacement-velocity correlation coefficient are involved besides the modal displacement correlation coefficient in normal CQC formula. The new algorithm of CCQC is not only as concise as that of the normal CQC but also has explicit physical meaning. The results obtained from complex mode superposition approaches are discussed and verified in some examples through step by step integration computation under a prescribed earth-quake motion input. From these examplary analyses, it may be pointed that the CCQC algorithm normally yields conservative outcome and that the forced mode uncoupling approach has good approximation even the discussed examplary structures are strongly non-proportional.     

TORSIONAL EFFECTS IN THE PUSHOVER-BASED SEISMIC ANALYSIS OF BUILDINGS

The general trends of the inelastic behaviour of plan-asymmetric structures have been studied. Systems with structural elements in both orthogonal directions and bi-axial eccentricity were subjected to bi-directional excitation. Test examples include idealised single-storey and multi-storey models, and a three-storey building, for which test results are available. The response in terms of displacements was determined by nonlinear dynamic analyses. The main findings, limited to fairly regular and simple investigated buildings, are: (a) The amplification of displacements determined by elastic dynamic analysis can be used as a rough, and in the majority of cases conservative estimate in the inelastic range, (b) Any favourable torsional effect on the stiff side, which may arise from elastic analysis, may disappear in the inelastic range. These findings can be utilised in the approximate pushover-based seismic analysis of asymmetric buildings, e.g. in the N2 method. It is proposed that the results obtained by pushover analysis of a 3D structural model be combined with the results of a linear dynamic (spectral) analysis. The former results control the target displacements and the distribution of deformations along the height of the building, whereas the latter results define the torsional amplifications. The proposed approach is partly illustrated and evaluated by test examples.     

Anton Raederscheidt’s Distorted Self-Portraits and Their Significance for Understanding Balance in Art

Following a right cerebral stroke, the German artist Anton Raederscheidt produced a remarkable series of self-portraits that depicted his severe visual neglect and gradual recovery. These distorted images, like those drawn by others with this disorder, inform us about lateral balance in art and why it is common in the art of cultures separated in time and space. After describing how artists in various cultures have employed lateral balance, I present Arnheim’s view that this aspect of art is the result of visual forces generated by the brain. Following a brief history of visual neglect, I present evidence that this disorder provides us with clues to the origin of the visual forces responsible for lateral balance in art. The relevant brain mechanisms control exploration of visual space by integrating orienting movements with visual spatial information. The prevalence of lateral balance in art becomes understandable when we consider that these brain mechanisms evolved to promote survival in our vertebrate ancestors. I end with a speculative neurological account of the aesthetics of lateral balance – why it is pleasing and its absence is displeasing.     

‘English ain't English in the Australian workplace’: a narrative analysis of Korean migrant women's labour market experiences

Drawing upon human capital theory, this article examines the labour market experiences of Korean migrant women in Australia. Narrative analysis reveals that Korean migrant women experience post-entry barriers in the Australian labour market. These barriers are not only attributable to their English language skills but also to their cultural background and personal orientations' aspirations. This article finds that migrants whose language, cultural and personal orientation and academic qualifications are similar to those of the dominant culture tend to feel less disadvantaged in the labour market. The narrative analysis allows Korean migrant women to describe symbolically in their own words their labour market experiences and the decisions, factors and emotions that constitute their experiences. The findings reinforce an increasing call for incorporating the cultural and personal aspects of human capital (beyond linguistic proficiency) into an understanding of the post-entry labour market experiences of migrant workers in their adopted country.     

Environmental Conditions of The Late Paleolithic and Early Neolithic Sites in Southern Sakhalin

The article presents the results of a palynological study conducted at Late Paleolithic (Olympiya-5 and Ogonki-5) and Early Neolithic (Slavnaya-5) sites located in the southern part of Sakhalin Island. The reconstructed environments оf Late Paleolithic sites in southern Sakhalin included dark coniferous (fir and spruce) forests, indicative of a relatively warm phases of the last stadial coinciding with Daansgard-Oeschger oscillations. The Early Holocene conditions in southern Sakhalin were relatively warm although a virtually complete absence of pollen of deciduous trees suggests that the Boreal period was not the Holocene climatic optimum in that region.     

Notes of papers read before the society through the Yangtse Gorges

Critics of spatial modeling make several damaging points: (1) results are often trivial; (2) they contradict a priori insights derived from theory or experience; and (3) they preclude an evaluation of the substantive coherence of theories. These critiques arise because analysts have selected criteria of statistical explanation over substantive interpretation. This paper reviews the trade‐off as exemplified by regression models. The paper then presents an alternative methodology, staged regression analysis, and discusses its three‐fold advantage over traditional regression models: (1) avoiding statistical‐substantive trade‐offs; (2) facilitating comparisons among spatial systems; and (3) evaluating and refining existing theory.     

基于ABAOUS的THG630卧式加工中心有限元静态分析

本文基于有限元分析软件ABAOUS,对THG630焊接结构卧式加工中心的立柱结构进行了静态分析,包括了钻孔和切削两种工况下的立柱变形和应力情况。为卧式加工中心的有限元动态分析奠定了理论基础。     

Analysis of sexual dimorphism of craniofacial traits using geometric morphometric techniques

This work deals with the assessment of cranial sexual dimorphism in human skeletal samples applying geometric morphometric techniques. The purpose of this research is to apply such techniques to quantitatively describe in craniofacial traits the degree and pattern of shape and size sexual dimorphism. Likewise, we evaluate the precision and accuracy of semilandmark‐based techniques for sex estimation. We employ a sample of 125 adult skulls of known sex from the Coimbra collection. A set of coordinate points was selected to describe glabella, mastoid, frontal and zygomatic processes. The results of intra‐class correlation coefficient (ICC) show excellent intra‐ and inter‐observer agreement (ICC > 0.96) in the location of the coordinates of points employed. The principal component analysis (PCA) performed on shape variables shows a large superposition of both sexes, suggesting a relatively low degree of dimorphism in shape. As a consequence, the average percentages of correct sex estimations based on these variables were of 60.12 and 68.90%, obtained by discriminant analysis with leave‐one‐out cross validation and k‐means clustering respectively. Conversely, when centroid size is included in PCA, females and males exhibit large separation along the first component. The highest values of correct assignment (77.86 and 72.15%) were found using shape–size variables with discriminant and k‐means clustering analysis, indicating that the traits analysed display marked sex differences related to the larger size and more robust features of males. Finally, the advantages of geometric morphometric techniques are discussed. Copyright © 2009 John Wiley & Sons, Ltd.