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The smoothness of the high-speed railway (HSR) on the bridge may exceed the allowable standard when an earthquake causes vibrations for HSR bridges, which may threaten the safety of running trains. Indeed, few studies have evaluated the exceeding probability of rail displacement exceeding the allowable standard. The purposes of this article are to provide a method for investigating the exceeding probability of the rail displacement of HSRs under seismic excitation and to calculate the exceeding probability.

In order to investigate the exceeding probability of the rail displacement under different seismic excitations, the workflow of analyzing the smoothness of the rail based on incremental dynamic analysis (IDA) is proposed, and the intensity measure and limit state for the exceeding probability analysis of HSRs are defined. Then a finite element model (FEM) of an assumed HSR track-bridge system is constructed, which comprises a five-span simply-supported girder bridge supporting a finite length CRTS II ballastless track. Under different seismic excitations, the seismic displacement response of the rail is calculated; the character of the rail displacement is analyzed; and the exceeding probability of the rail vertical displacement exceeding the allowable standard (2mm) is investigated.

The results show that: (1) The bridge-abutment joint position may form a step-like under seismic excitation, threatening the running safety of high-speed trains under seismic excitations, and the rail displacements at mid-span positions are bigger than that at other positions on the bridge. (2) The exceeding probability of rail displacement is up to about 44% when PGA = 0.01g, which is the level-five risk probability and can be described as 'very likely to happen'. (3) The exceeding probability of the rail at the mid-span positions is bigger than that above other positions of the bridge, and the mid-span positions of the track-bridge system above the bridge may be the most hazardous area for the running safety of trains under seismic excitation when high-speed trains run on bridges.

The work extends the seismic hazardous analysis of HSRs and would lead to a better understanding of the exceeding probability for the rail of HSRs under seismic excitations and better references for the alert of the HSR operation.

This study aims to assess policies and mechanisms in Caribbean and Pacific small island developing states (SIDS) that address climate-induced migration and displacement. The migration of communities away from vulnerable regions is highly likely to be an adaptation strategy used in low-elevation SIDS, as the impacts of climate change are likely to result in significant loss and damage, threatening their very territorial existence. SIDS must ensure that residents relocate to less vulnerable locations and may need to consider international movement of residents. Ad hoc approaches to migration and displacement may result in increased vulnerability of residents, making the development and enforcement of comprehensive national policies that address these issues a necessity.

Interviews with United Nations Framework Convention on Climate Change (UNFCCC) negotiators for SIDS as well as analysis of secondary data, including Intended Nationally Determined Contributions, are utilized to determine policies and mechanisms in place that focus on climate-induced migration and displacement.

While climate change is acknowledged as an existential threat, few SIDS have policies or mechanisms in place to guide climate-induced migration and displacement. Potential exists for migration and displacement to be included in policies that integrate disaster risk reduction and climate change adaptation along with national sustainable development plans. Regional bodies are beneficial to providing guidance to SIDS in the development of nationally appropriate frameworks to address climate-induced migration and displacement.

Existing gaps in policies and mechanisms and challenges faced by SIDS in developing strategies to address climate-induced migration and displacement are explored. Best practices and recommendations for strategies for SIDS to address migration and displacement are provided.

This paper aims to design an active shock absorber scheme for use in conjunction with a passive shock absorber to suppress the horizontal vibration of elevator cars in a smaller range and shorter time. The developed active shock absorber will also improve the safety and comfort of passengers driving in ultra-high-speed elevators.

A six-degree of freedom dynamic model is established according to the position and condition of the car. Then the active shock absorber and disturbance compensation-based adaptive control scheme are designed and simulated in MATLAB/Simulink. The results are analysed and compared with the traditional shock absorber.

The results show that, compared with traditional spring-based passive damping systems, the designed active shock absorber can reduce vibration displacement by 60%, peak acceleration by 50% and oscillation time by 2/3 and is more robust to different spring stiffness, damping coefficient and load.

The developed active shock absorber and its control algorithm can significantly reduce vibration amplitude and converged time. It can also adjust the damping strength according to the actual load of the elevator car, which is more suitable for high-speed elevators.

This paper aims to assess to what extent South American countries have integrated recommendations of the international agenda to address human mobility in the context of disasters and climate change in their national laws and policies.

This research sought to find the level of discussions around human mobility in disaster laws, NDCs and National Adaptation Plans (NAPs) by looking for a range of search terms connected to human mobility in the context of disasters and climate change, followed by the content analysis of these terms.

Some advances with regards to human mobility are already confirmed in the domestic level of South American countries through humanitarian visas to disaster displaced persons and the inclusion of the topic in the DRR, climate change laws, NAPs and INDCs/NDCs. But they have not developed specific strategies with regards to it. Hence, their advances still require that national norms and policies are harmonized with the international guidelines. This will enable to fill the protection gap of people in context of disasters and climate change.

The results assess the level of harmonization above-mentioned between international instruments with national policies on human mobility in the context of disasters and climate change in South America.

The purpose of the work is to provide a comprehensive review of the digital image correlation (DIC) technique for those who are interested in performing the DIC technique in the area of manufacturing.

No methodology was used because the paper is a review article.

no fundings.

Herein, the historical development, main strengths and measurement setup of DIC are introduced. Subsequently, the basic principles of the DIC technique are outlined in detail. The analysis of measurement accuracy associated with experimental factors and correlation algorithms is discussed and some useful recommendations for reducing measurement errors are also offered. Then, the utilization of DIC in different manufacturing fields (e.g. cutting, welding, forming and additive manufacturing) is summarized. Finally, the current challenges and prospects of DIC in intelligent manufacturing are discussed.

The purpose of this paper is to present the major gaps in the field of planning policy and its implementation regarding climate change and disaster risk reduction (DRR), with special reference to the displacement of people, together with the knowledge needed to increase community resilience. The researched relations are illustrated by the example of Serbia. The Republic of Serbia has been faced with increasingly visible impacts of climate change in recent years – floods, heat waves, droughts and others. During the floods that hit Serbia in 2014, over 30,000 people experienced displacement. These events have triggered numerous efforts, both to repair the incurred damage and to analyze opportunities for prevention.

This research has used document analysis to investigate contemporary approaches defined by policies, programs and research reports regarding climate change and DRR, with special reference to the displacement of people. An analytical framework has been used to evaluate to what extent the planning policy framework in Serbia addresses these issues in the context of achieving resilient development. Secondary analysis of research data has been used to recognize the gaps and identify needs for increasing community resilience.

Based on the growing trends in projections of climate change as a result of induced natural disasters for the region in the future and international trends in coping with these issues, this paper argues that it is necessary to improve the implementation of the planning policy framework and the capacities of professionals and citizens, to reduce future displacement and increase community resilience to climate change. The key weaknesses found within DRR and the emergency management system in Serbia were the lack of an appropriate information base of the cadastre of risk zones and the lack of information and coordination of actors on the local to the national level. During the “pre-disaster” period, findings stress a weak partnership and capacity development practice at the local level, as well as between local responsible bodies and regional/national entities in charge of emergency management and DRR. The paper singles out the main preconditions for achieving effective resilient planning, so that such a plan can move “people away from marginal areas” and provide living conditions that are resilient.

This paper provides a comprehensive insight analysis of the relations between climate change and DRR, with special reference to the planning policy. Using the lessons learned from the recent climate-induced disaster with its implications on displacement, the paper identifies needs for strengthening capacities to establish more resilient communities in Serbia. The gaps and needs identified, as well as the recommendations provided, may be of value for neighboring countries as well, who face similar challenges in climate change adaptation and who need to increase disaster risk resilience.

Terrestrial laser scanning (TLS) point clouds have been widely used in deformation measurement for structures. However, reliability and accuracy of resulting deformation estimation strongly depends on quality of each step of a workflow, which are not fully addressed. This study aims to give insight error of these steps, and results of the study would be guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds. Thus, the main contributions of the paper are investigating point cloud registration error affecting resulting deformation estimation, identifying an appropriate segmentation method used to extract data points of a deformed surface, investigating a methodology to determine an un-deformed or a reference surface for estimating deformation, and proposing a methodology to minimize the impact of outlier, noisy data and/or mixed pixels on deformation estimation.

In practice, the quality of data point clouds and of surface extraction strongly impacts on resulting deformation estimation based on laser scanning point clouds, which can cause an incorrect decision on the state of the structure if uncertainty is available. In an effort to have more comprehensive insight into those impacts, this study addresses four issues: data errors due to data registration from multiple scanning stations (Issue 1), methods used to extract point clouds of structure surfaces (Issue 2), selection of the reference surface S_ref to measure deformation (Issue 3), and available outlier and/or mixed pixels (Issue 4). This investigation demonstrates through estimating deformation of the bridge abutment, building and an oil storage tank.

The study shows that both random sample consensus (RANSAC) and region growing–based methods [a cell-based/voxel-based region growing (CRG/VRG)] can be extracted data points of surfaces, but RANSAC is only applicable for a primary primitive surface (e.g. a plane in this study) subjected to a small deformation (case study 2 and 3) and cannot eliminate mixed pixels. On another hand, CRG and VRG impose a suitable method applied for deformed, free-form surfaces. In addition, in practice, a reference surface of a structure is mostly not available. The use of a fitting plane based on a point cloud of a current surface would cause unrealistic and inaccurate deformation because outlier data points and data points of damaged areas affect an accuracy of the fitting plane. This study would recommend the use of a reference surface determined based on a design concept/specification. A smoothing method with a spatial interval can be effectively minimize, negative impact of outlier, noisy data and/or mixed pixels on deformation estimation.

Due to difficulty in logistics, an independent measurement cannot be established to assess the deformation accuracy based on TLS data point cloud in the case studies of this research. However, common laser scanners using the time-of-flight or phase-shift principle provide point clouds with accuracy in the order of 1–6 mm, while the point clouds of triangulation scanners have sub-millimetre accuracy.

This study aims to give insight error of these steps, and the results of the study would be guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds.

The results of this study would provide guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds. A low-cost method can be applied for deformation analysis of the structure.

Although a large amount of the studies used laser scanning to measure structure deformation in the last two decades, the methods mainly applied were to measure change between two states (or epochs) of the structure surface and focused on quantifying deformation-based TLS point clouds. Those studies proved that a laser scanner could be an alternative unit to acquire spatial information for deformation monitoring. However, there are still challenges in establishing an appropriate procedure to collect a high quality of point clouds and develop methods to interpret the point clouds to obtain reliable and accurate deformation, when uncertainty, including data quality and reference information, is available. Therefore, this study demonstrates the impact of data quality in a term of point cloud registration error, selected methods for extracting point clouds of surfaces, identifying reference information, and available outlier, noisy data and/or mixed pixels on deformation estimation.

This study aims to propose a vertical coupling dynamic analysis method of vehicle–track–substructure based on forced vibration and use this method to analyze the influence on the dynamic response of track and vehicle caused by local fastener failure.

The track and substructure are decomposed into the rail subsystem and substructure subsystem, in which the rail subsystem is composed of two layers of nodes corresponding to the upper rail and the lower fastener. The rail is treated as a continuous beam with elastic discrete point supports, and spring-damping elements are used to simulate the constraints between rail and fastener. Forced displacement and forced velocity are used to deal with the effect of the substructure on the rail system, while the external load is used to deal with the reverse effect. The fastener failure is simulated with the methods that cancel the forced vibration transmission, namely take no account of the substructure–rail interaction at that position.

The dynamic characteristics of the infrastructure with local diseases can be accurately calculated by using the proposed method. Local fastener failure will slightly affect the vibration of substructure and carbody, but it will significantly intensify the vibration response between wheel and rail. The maximum vertical displacement and the maximum vertical vibration acceleration of rail is 2.94 times and 2.97 times the normal value, respectively, under the train speed of 350 km·h⁻¹. At the same time, the maximum wheel–rail force and wheel load reduction rate increase by 22.0 and 50.2%, respectively, from the normal value.

This method can better reveal the local vibration conditions of the rail and easily simulate the influence of various defects on the dynamic response of the coupling system.

The purpose of this study concerns numerical studies and experimental validation of the mechanical behavior of hybrid specimens. These kinds of composite specimens are made up of thin carbon and glass substrates on which some Macro Fiber Composite^® (MFC) piezoelectric patches are glued. A proper design and manufacturing of the hybrid specimens as well as testing activities have been performed. The research activity has been carried out under the FutureWings project, funded by the European Commission within the 7th Framework.

The paper describes the basic assumptions made to define specimen geometries and to carry out experimental tests. Finite element (FE) results and experimental data (laser technique measurements) have been compared: it shows very good agreement for the displacements’ distribution along the specimens.

Within the objectives of the project, the study of passive and active deformation characteristics of the hybrid composite material has provided reference technical data and has allowed for the correct adaptation of the FE models. More in particular, using the hybrid specimens, both the bending deformations and the torsion deformations have been studied.

The deformation capability of the hybrid specimens will be used in the development of prototypical three-dimensional structures, that, through the electrical control of the MFC patches, will be able to change the curvature of their cross section or will be able to change the angle of torsion along their longitudinal axis.

The design of nonstandard specimens and the tests executed represent a novelty in the field of structures using piezoelectric actuators. The numerical and experimental data of the present research constitute a small step forward in the field of smart materials technology.

This paper employs the gravity model to investigate how the growth of China’s textile and clothing (T&C) exports is displacing the exports of other Asian developing countries over the 1990-2015 period. Aggregate analyses were undertaken, and the endogeneity of Chinese exports were accounted by applying instrumental variables with country fixed effects. It was found that there was a negative impact of China’s emergence on T&C exports on other Asian developing countries. We further explored whether such displacement effect varies across Asian countries and the results showed that a more pronounced effect was found in low-income countries than high-income ones. Our findings suggest that the export competitiveness of China’s neighbors, i.e. both more and less developed Asian countries, are affected by the emergence of China in T&C Trade. The implications of China’s One Belt, One Road initiative are also discussed.