The Jaws Effect: How movie narratives are used to influence policy responses to shark bites in Western Australia

This article examines the way political actors use film narratives to influence policymaking following shark bites. To analyse these relationships I propose the concept of the Jaws Effect, where film-based historical analogies are used as a political device to frame real-life events in ways that make the events governable and prejudice certain policy options. Three elements of the Jaws Effect are reviewed including the intentionality of the shark, perception that these events are fatal and the belief that ‘the shark’ must be killed. These elements are applied to a case study of policy responses to shark bite episodes in Western Australia in 2000, 2003, 2011 and 2014. The reasons why this political device may not always work are also suggested.

本文研究了政治主体以什么方式使用电影叙事来影响鲨鱼咬人之后的政策制定。笔者提出“《大白鲨》效应”的概念,也就是以取自电影的历史类比为政治手段来言说现实生活中的事件,让事件根据言说者的需要,不利于某些政策选择。本文分析了《大白鲨》效应的三要素：鲨鱼的目的性;现实生活的事件性命攸关;鲨鱼必须被杀死。笔者将三要素用于研究2000、2003、2011和2014年西澳大利亚鲨鱼要人事件之后的政策反应。文章也探讨了为什么这种政治手法并不总能凑效。     

浅析名人效应下的书画收藏误区

名人效应是我国历代书画艺术领域中引人关注的重要现象,这一现象反映在艺术市场上,是书画价格的高低不在于其作品质量如何,而主要取决于其作名气的大小;这种艺术价值与市场价格的错位,成为中国书画艺术及其市场发展的“瓶颈”。为此,本对这种“瓶颈”的现象、成因及其对策做了深入的探讨和论述。     

Investigating the likelihood of a reservoir offset in the radiocarbon record for ancient Egypt

Some radiocarbon dates for ancient Egypt have been significantly offset from the established historical chronology (see Bonani et al., 2001). In this paper, short-lived plant species collected in Egypt between 1700 and 1900 AD were used to investigate the possibility that the radiocarbon record had been influenced by reservoir effects. AMS radiocarbon measurements were made on 66 known-age samples, resulting in an average offset from expected values of 19 years. The implications of this minor discrepancy on the likelihood of a reservoir process are discussed, and the agreement of the data with recent models of radiocarbon seasonality is also considered.     

A Stability-Based Target Displacement for Direct Displacement-Based Design of Bridge Piers

P-Δ effects can cause instability if they are not properly accounted for during the design of bridge piers and other structures. When a bridge pier is designed with the Direct Displacement-Based Design Method, P-Δ effects are evaluated at the end of the design process and compared to the flexural strength of the pier to find a stability index. If the stability index exceeds the specified value, the design must be repeated, iteratively reducing the target design displacement. This article presents a model that when used at the beginning of design (without knowledge of strength) allows the estimation of the maximum lateral displacement that a bridge pier can sustain without exceeding the specified value of the stability index, therefore eliminating the need for iteration. The examples that are presented prove that the model is accurate and very useful for design of extended pile bents.     

Dynamic Stability and Design of C-Bent Columns

Symmetrically reinforced bridge columns with a horizontal cantilever in one direction, called C-bent columns, tend to deform predominantly in the direction of applied moment when subject to strong earthquake shaking. For this reason, the strength in the direction of applied moment is generally increased in design. This article describes the use of inelastic dynamic time history analyses with a suite of ground motion records to quantify the amount of strength increase required to minimize likely peak and permanent displacement demands. It is shown that the strength should be increased by approximately 2.3 times the applied moment in design.     

Shake Table Test and Numerical Analysis of a Bridge Model Supported on Elastomeric Pad Bearings

Elastomeric pad bearings are widely applied in short- to medium-span girder bridges in China, with the superstructure restrained by reinforced concrete (RC) shear keys in the transverse direction. Field investigations after the 2008 Wenchuan earthquake reveal that bearing systems had suffered the most serious damage, such as span falling, bearing displaced, and shear key failure, while the piers and foundations underwent minor damage. As part of a major study on damage mechanism and displacement control method for short- to medium-span bridges suffered in Wenchuan earthquake, a 1:4 scale, two-span bridge model supported on elastomeric pad bearings were recently tested on shake tables at Tongji University, Shanghai. The bridge model was subjected to increasing levels of four seismic excitations possessing different spectral characteristics. Two restraint systems with and without the restraint of RC shear keys were tested. A comprehensive analytical modeling of the test systems was also performed using OpenSees. The experimental results confirmed that for the typical bridges on elastomeric pad bearings without RC shear keys, the sliding effect of the elastomeric pad bearings plays an important role in isolation of ground motions and, however, lead to lager bearing displacement that consequently increases the seismic risk of fall of span, especially under earthquakes that contain significant mid-period contents or velocity pulse components. It is suggested from the test results that RC shear keys should be elaborately designed in order to achieve a balance between isolation efficiency and bearing displacement. Good correlation between the analytical and the experimental data indicates that the analytical models for the bearing and RC shear key as well as other modeling assumptions were appropriate.     

东北亚地区国际经济合作的文化地理研究

本文以地域文化观点,历史地论证了东北亚地区民族文化的若干相近之点;根据东北亚地区社会经济发展的不平衡,论述了地区经济合作的必要与可能;随着地区经济的大规模合作,必然加强其间的科学文化交流,从而将产生巨大的文化地理效应,并可能在原有基础上形成更具地域性的文化圈。     

Definition of Seismic Input for Out-of-Plane Response of Masonry Walls: I. Parametric Study

Response of masonry walls to out-of-plane excitation is a complex, yet inadequately addressed theme in seismic analysis. The seismic input expected on an out-of-plane wall (or a generic “secondary system”) in a masonry building is the ground excitation filtered by the in-plane response of the walls and the floor diaphragm response. More generally, the dynamic response of the primary structure, which can be nonlinear, contributes to the filtering phenomenon. The current article delves into the details and results of several nonlinear dynamic time-history analyses executed within a parametric framework. The study addresses masonry structures with rigid diaphragm response to lateral loads. The scope of the parametric study is to demonstrate the influence of inelastic structural response on the seismic response of secondary systems and eventually develop an expression to estimate the seismic input on secondary systems that explicitly accounts for the level of inelasticity in the primary structure in terms of the displacement ductility demand. The proposed formulation is discussed in the companion article.     

Effect of Shaft Diameter of Pile on Lateral Winkler Springs' Stiffness

Soil was modelled with linearly elastic three-dimensional finite elements. Lateral spring stiffness was calculated from FE results. Spring stiffness is shown varying linearly with shaft diameter. It is also found that spring stiffness is inversely proportional to powers (less than unity) of pile flexural rigidity. Scaling factors for shaft diameter and pile flexural rigidity are introduced. Basic stiffness of lateral spring is studied considering both full vertical slippage and zero slippage between the soil and the pile. Relevant relationships for stiffness are proposed. Some applications are suggested.     

Optimal Spectral Acceleration-based Intensity Measure for Seismic Collapse Assessment of P-Delta Vulnerable Frame Structures

This study proposes an “optimal” spectral acceleration-based intensity measure (IM) to assess the collapse capacity of highly inelastic frame structures vulnerable to the P-delta effect. The IM is derived from the geometric mean of the spectral pseudo-acceleration over a certain period interval. The lower bound period of the averaging interval is related to the mode in which 95% of the effective modal mass is exceeded. The upper bound period is 1.6 times the fundamental period. This IM provides minimum, or close to the minimum, dispersion for frames with different fundamental periods of vibration, or number of stories.