NOTE ON THE INCLUSION OF SITE CLASSIFICATION INFORMATION IN EQUATIONS TO ESTIMATE STRONG GROUND MOTIONS

Two main regression methods have been proposed for using site category information within ground motion prediction equations, these are: (a) joint estimation of the site category coefficients and the magnitude and distance coefficients; or (b) estimation of site category coefficients by using the residuals from the equation derived without considering soil conditions. Method (a) requires each record be assigned a site category whereas for method (b), because it relies on residuals, site information can be missing for some records. This short note finds that if the mean of the transformed distances within each site category is the same then the two methods give the same site coefficients. If, however, these means are significantly different then method (b) can yield incorrect site coefficients.     

A DAMAGE MODEL FOR THE ANALYSIS OF THE SEISMIC RESPONSE OF MONUMENTAL BUILDINGS

In this paper the Author proposes a damage model for the analysis of masonry plates and shells, which is based on an improvement of a previous constitutive model. The modifications introduced, connected to the head joint damage, allow us to study the influence of masonry texture on the damage modes once the mechanical characteristics of the elements constituting the masonry and the results of tests on simple assemblages are known. Having a nonlinear constitutive model is certainly one of the basic elements for understanding the damage mechanisms in masonry buildings. If, in fact, an elastic-linear constitutive model may be used under normal loading conditions, in critical situations it is necessary to model the damage and the dissipation mechanisms that occur between the elements, stone (brick) and mortar, in correlation with their characteristics and kind of masonry. To validate the model a comparison is made between the numerical and experimental results, in the case of tests available in the literature in masonry panels subjected to out-of plane loading and in a real structure through the observation of the damage in Umbria (Italy) surveyed after the 1997 earthquake.     

A MICROMECHANICAL INELASTIC MODEL FOR HISTORICAL MASONRY

A micromechanical damage model for the Snite element modelling of historical masonry structures is presented in this article. Masonry is considered as a composite medium made up of a periodic assembly of blocks connected by orthogonal bed and head mortar joints. The constitutive equations, in plane stress, are based on the homogenisation theory and they consider the non linear stress-strain relationship in terms of mean stress and mean strain. Different in-plane damage mechanisms, involving both mortar and blocks, are considered and the damage process is governed by evolution laws based on an energetic approach derived from Fracture Mechanics and on a non-associated Coulomb friction law. The failure domain of the model is analysed both in the equivalent stress and in the principal stress space considering different orientations of the bed joints relative to the loading direction. A comparison with experimental results is provided. A numerical simulation of masonry walls subjected to horizontal forces proportional to their own weight is shown in order to discuss the model's capability of describing the influence of the masonry microstructure on its mechanical behaviour.     

信息技术对南京城市居民休闲活动与出行的影响

从网络休闲角度出发,运用结构方程模型就信息技术对南京城市居民休闲活动与出行的影响进行实证研究,探索居民社会经济属性、信息化水平、网络休闲活动和出行之间的关系。结果显示:信息技术对南京城市居民的休闲活动已经产生了广泛的影响;而网络休闲活动的增加也确实减少了居民每日的非必要性出行时间,说明对居民出行有替代或修正性的影响;此外,居民的社会经济属性是影响居民网络休闲活动和出行选择的根本,其中,年龄和学历,学历和收入,分别是当前影响居民网络休闲活动状况以及居民出行方式选择的关键。     

Quantitative estimation of overpressure caused by gas generation and application to the Baiyun Depression in the Pearl River Mouth Basin,South China Sea

Hydrocarbon generation can yield high fluid pressures in sedimentary basins as the conversion of solid kerogen to hydrocarbons can result in an increase in fluid volume. To quantify the relationship between gas generation and overpressure in source rocks, a set of equations for computing the pressure change due to gas generation has been derived. Those equations can be used to quantitatively estimate overpressure generated by type III kerogen in source rocks by considering gas generation and leakage, gas dissolution in formation water and residual oil, thermal cracking of oil to gas, and hydrocarbon episodic expulsion from source rocks. The equations also take consideration of other factors including source rock porosity, transformation ratio, total organic carbon (TOC), hydrogen index, and compressibility of kerogen, oil, and water. As both oil and gas are taken into account in the equations, they can also be used to estimate the evolution of overpressure caused by hydrocarbon generation of type I and type II kerogen source rocks. Sensitivity analyses on the type III kerogen source rock indicate that hydrogen index is the most influential parameter for overpressure generation, while TOC and residual gas coefficient (β: ratio of residual gas over the total gas generated) have a moderate effect. Overpressure can be generated even if the gas leakage/loss in the source rock is up to 80% of the total gas generated. This suggests that the internal pressure seal of the source rock is not a critical factor on the pressure change as long as the source rocks are capable of sealing liquid oil. The equations were applied to evaluate the overpressure in the Eocene–Oligocene Enping Formation source rocks due to hydrocarbon generation in the Baiyun Depression, the Pearl River Mouth Basin by considering the source rock properties, hydrocarbon generation history, and hydrocarbon expulsion timing. Two episodes of overpressure development due to gas generation and release were modeled to have occurred in the Enping Formation source rock since 16 Ma. The overpressure release at 10.2–5.3 Ma via hydrocarbon expulsion was apparently related to the Dongsha phase of tectonic deformation, whereas the pressure release at 2–0 Ma was due to pressure generation that was exceeded the fracture‐sealing pressure in the source rocks.     

New regression equations for stature estimation for medieval Scandinavians

Estimating stature from skeletal remains in an archaeological context requires appropriate methods that take into account possible temporal and spatial changes in body proportions. New regression equations—both least squares (LSQ) and reduced major axis (RMA) equations—were thus developed for estimating living stature from the long bone lengths of medieval inhabitants (N = 60) of Westerhus, Sweden. The living stature of these skeletal specimens was determined by using the anatomical method. Findings in this study reveal that LSQ regression equations systematically overestimate statures of short individuals and underestimate those of tall individuals, whereas the RMA equations—both combined sexes and sex‐specific equation—provide more accurate stature estimations for individuals of very different statures. The combined sexes RMA‐equations should be used for cases in which the sex is unknown because they provide more accurate stature estimations than sex‐specific equation with a wrong sex determination. These new equations are more appropriate than generally used regression equations for estimating statures of the medieval period Scandinavians. Copyright © 2009 John Wiley & Sons, Ltd.     

On the intrinsic accuracy and precision of luminescence dating techniques for fired ceramics

Luminescence dating techniques have been used extensively for archaeological and geological samples. Such techniques are based on thermally or optically stimulated signals. This paper presents simulations of several luminescence techniques for equivalent dose (ED) estimation for ceramic materials containing quartz. The simulations are carried out using a recently published comprehensive kinetic model for quartz, consisting of 11 electron and hole traps and centers. The complete sequence of the experimental protocols for several thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques are simulated using the same set of kinetic parameters. The specific simulated protocols are: additive dose TL protocol, predose technique (both additive and multiple activation versions), phototransfer protocol, single aliquot regenerative optically stimulated luminescence (SAR-OSL) protocol, and SAR thermoluminescence protocol (SAR-TL). One hundred random variants of the natural samples were generated by keeping the transition probabilities between energy levels fixed, while allowing simultaneous random variations of the concentrations of the 11 energy levels. The relative intrinsic accuracy and precision of the protocols are simulated by calculating the equivalent dose (ED) within the model, for a given natural burial dose of the sample. The intrinsic accuracy of these techniques is estimated by simulating natural irradiation of the samples with a known burial dose, followed by simulation of the luminescence method used to recover the estimated dose ED. The percent difference between the burial dose and the ED value represents the simulated accuracy of the luminescence technique. The relative intrinsic precision of these techniques is estimated by fitting Gaussian probability functions to the ED values obtained with the 100 model variants. It is found that the various techniques can reproduce natural paleodoses in the range 10 mGy–10 Gy with a typical intrinsic accuracy of +1 to 10%. Techniques based on single aliquot protocols were found in general to be more precise than techniques requiring the use of multiple aliquots. In addition, techniques based on interpolation of experimental data were found to be consistently both more precise and accurate than those based on extrapolation of experimental data.     

Using General Estimating Equations to Analyze Oral Health in the Moche Valley of Perú

This study introduces a new method for analyzing oral health indicators and thus reconstructing diet. To this end, we examined the dental remains of 173 individuals recovered from the site of Cerro Oreja in the Moche Valley of Perú, who lived during the Salinar (400–1 BC) or Gallinazo (AD 1–200) phases. The infectious and degenerative conditions analyzed include: dental caries, dental wear, dental abscess, antemortem tooth loss and dental calculus, all of which have been used to track dietary and thus subsistence‐related economic and sociopolitical changes. Data were analyzed using generalized estimating equations, an extension of generalized linear models. Significant changes in the frequency of occurrence of most dental conditions suggest that during the period of study, there was an increase in the consumption of agricultural products. However, these changes in oral health did not equally affect females and males. By the end of the Gallinazo phase, significant sex differences developed, with females more often affected by dental caries and males displaying greater mean molar wear scores. Copyright © 2011 John Wiley & Sons, Ltd.     

Transposition in Japanese state identities: overseas troop dispatches and the emergence of a humanitarian power?

This article aims to illustrate the trajectory of Japan's security identity transposition. As one of the catalysts in identity transposition, it focuses on the constitutive roles of norms regulating Japan's overseas dispatches of the Self-Defense Forces (SDF). Whilst keeping the identities of ‘a peace state’ and ‘a civilian power’, the authors argue that Japan has crafted a new security identity after the end of the cold war and the 9/11 terrorist attacks—namely, ‘an international humanitarian power’. As evidence of this transposition, the authors illustrate a dramatic increase in the number of overseas SDF dispatches on humanitarian missions, and the shift of domestic and foreign responses to it. The authors note that Japan has been on the road to remilitarisation and internationalisation during the past four decades through the enactments of laws for overseas SDF dispatches, the general public's shift of attitude on the SDF's roles, the evolution of the alliance in a more operational direction, and the creation of threats from North Korea and China. Lastly, the authors argue that there is still a long way to go before Japan emerges as a normal state because of the presence of many domestic and structural barriers, especially multiple identities defining the Japanese state.     

Modelling the effect of Mesolithic populations on the slowdown of the Neolithic transition

The expansion of the Neolithic transition in Europe took place gradually from the Near East across the whole continent. At Northern Europe, observations show a slowdown in the speed of the Neolithic front in comparison to other regions of the continent. It has been suggested that the presence of high population densities of hunter-gatherers at the North could have been the main cause for this slowdown. This proposal has recently been described by a mathematical model that takes into account: (i) the resistance opposed by the Mesolithic populations to the advance of Neolithic populations in their territory, and (ii) a limitation on the population growth dynamics due to the competition for space and resources. But these two effects are not equally responsible for the slowdown of the spread. Indeed, here we show that the limitation on the population growth dynamics seems to have been the main cause of the delay of the expansion of farming in Northern Europe.