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This briefing provides a short introduction to a supplement of the Ciria Manual on Scour at Bridges and Other Hydraulic Structures published in 2021. The supplement captures additional knowledge since the scour manual was published in 2015. This note is intended for designers and asset managers of structures in the water environment that may be subject to scour.

Past bridge failures due to earthquakes have been found to be due to inadequate seismic design of the bridge piers. It is thus essential to investigate the effect of lateral confinement on the seismic behaviour of bridge piers. The aim of this study was to evaluate, experimentally and numerically, the seismic performance of reinforced concrete bridge piers with various types of transverse reinforcement. For this purpose, three scaled-down (1 : 4) circular bridge pier specimens were tested under constant axial and quasi-static cyclic loading (QSCL). A control specimen was made with spiral lateral reinforcement, while the other two specimens were made with stirrups with cross-ties and strips with cross-ties. The hysteresis loops, envelope curves, energy dissipation and stiffness degradation of all three specimens were determined in order to evaluate their seismic behaviour. Compared with the control specimen, the specimen with strips and cross-ties showed increased lateral load capacity, cumulative energy dissipation and higher initial stiffness due to the effect of increased confinement. The results of finite-element analysis showed good agreement with the experimental results. The findings of this study indicate that strips with cross-ties can be used in bridge piers when a high lateral load carrying capacity and energy dissipation are required.

The performance of integral bridges subjected to a multi-component earthquake has not been thoroughly investigated. Here, the responses of an integral bridge subjected to three-component far- and near-field earthquakes are determined to evaluate its relative structural advantages and disadvantages over a conventional bridge. Further, the effect of the interaction between the internal forces in the three directions on the total responses or yielding due to simultaneous application of the three components of an earthquake is investigated. For this purpose, two geometrically comparable bridges, one integral and other conventional, are analysed under far- and near-field earthquakes using SAP2000. The parameters varied are the type of ground motion, peak ground acceleration and orientation of the major horizontal component of the ground motion. Seismic demand parameters include the maximum bending moment in the girders, maximum moments at the top and bottom of piers, displacements in three directions and the plastic hinges formed. The results of the analysis show that the deck of the integral bridge has smaller displacements when compared with the conventional bridge. A greater number of plastic hinges are formed in the integral bridge, but the degree of damage shown by the hinge rotations in the conventional bridge is greater.

The Wan Jiang Bridge in China was damaged by ship impact and subsequently restored. This paper presents a detailed evaluation of the residual service life (RSL) of the bridge using the reliability analysis method of the Joint Committee on Structural Safety, based on the structural load-bearing capacity (LBC) of the bridge and the design load. Data were collected from bridge design codes, field loading tests and finite-element (FE) analysis. The LBC was initially calculated and subsequently revised using specific coefficients. Using FE analysis, the bending moment on the control section of the bridge was determined under the most unfavourable loading conditions and the ultimate LBC of the bridge was checked. Subsequently, static and dynamic loading tests on the restored bridge were conducted, with the load and capacity determined for the control section based on FE analysis. The loads considered were dead load, vehicle load and crowd load. A time-dependent reliability index was developed for the restored bridge using the probability distributions of capacity and design load variables, and the RSL was determined. This case study, predicting the RSL of the bridge based on a multitude of data, should be valuable for future bridge maintenance and management.

This paper reports on a numerical study into the crack-dependent behaviour of a steel-plate girder bridge strengthened with carbon-fibre-reinforced polymer sheets. Progressive cracking, which represented fatigue-induced damage, was simulated from up to 10% of the girder depth. Finite-element analysis was used to evaluate the performance of the control, damaged and strengthened cases subject to standard US highway fatigue loading. The efficacy of polymer strengthening was also examined from a strength perspective, using the load factor rating method and the load and resistance factor rating method. Localised fatigue cracking caused a stress concentration along the girder and its progression rate was related to the degree of web fracture. The damage of the tensile flange was more influential in reducing the flexural capacity of the girder relative to damage of the web. The strengthening decreased the stress ranges, thereby increasing the fatigue life of the girder, and enhanced the maximum average daily traffic capacity. Reliability modelling indicated a transition in failure rates before and after 3% cracking in the girder, supporting the extended functional time resulting from strengthening.

To understand the influence of the layout and geometric parameters of the lining concrete on the mechanical properties of multi-cell single-box girder bridges with corrugated steel webs, the Fenghua River Bridge is taken as an example. This is a single-box three-cell continuous girder bridge with corrugated steel webs that is the largest of its kind in China. It was used to establish the finite-element model in this paper. The results of this study suggest that the lining concrete single-side arrangement has good economic and mechanical properties. The influence of the geometric parameters of the lining concrete on the mechanical properties of the structure was studied using the finite-element model, and the length and thickness range of the lining concrete of the single-box multi-cell composite girder bridge with corrugated steel webs are provided. The research results provide useful suggestions for the design of lining concrete in real bridge projects, and thereby make up the gap in the existing code.

Different methodologies have been suggested in the literature to simulate the adverse impact of reinforcement corrosion on the non-linear structural behaviour of deteriorated reinforced concrete (RC) structures. The modelling methodology used, however, can significantly bias the predicted time-dependent structural behaviour of deteriorated structures. Considering the critical importance of numerical modelling in bridge maintenance scheduling and effective decision making, the influence of different modelling strategies on the anticipated time-variant structural performance of corroded concrete bridge columns is investigated. To this end, various simple and advanced modelling methodologies are evaluated. The effect of the considered modelling scenarios on the estimation of damage limit states, the sequence of multiple failure modes, structural capacity (both ductility and strength) and energy dissipation capacity of a benchmark circular RC column is evaluated over its service life. The results show that the modelling strategy significantly affects the predicted time-variant structural performance of the deteriorated structure.

Scouring around piers is recognised as one of the main causes of bridge failure. Local scour refers to the localised erosion of soil at piers and abutments caused by flow-induced vortices around their base. This paper studies experimentally the response of a bridge pier, supported on a cylindrical embedded foundation, subjected to flood-induced scour. A hybrid two-step methodology is developed to study the hydraulic and the mechanical part of the problem. In the first step, the hydraulic problem of local scour around a pier is experimentally modelled in 1g using a recently developed miniaturised tidal generator. The experimentally generated scour hole is then three-dimensionally scanned to produce a three-dimensional (3D)-printed mould. The latter is used in the second step to reproduce the scour hole in an Ng model, subsequently tested in a drum centrifuge to study the mechanical part of the problem under proper stress scaling. Foundation performance before and after local scour is studied through vertical, lateral monotonic and slow cyclic pushover tests. The effects of general (uniform) scour are also investigated by removing a soil layer of constant thickness. Local scour is shown to have a minor effect on vertical bearing capacity. In stark contrast, the lateral performance is significantly affected, with the foundation moment capacity Mult being reduced by up to 38%. The effect of general scour is even more pronounced, leading to 48% reduction of Mult. The rate of cyclic settlement accumulation is also much more severely affected by general scour as compared to local scour. Overall, the effects of local scour on foundation performance differ substantially to those of general scour, bringing into question the common simplification of ignoring the geometry of the scour hole, making no distinction between local and general scour.

Vibration properties of civil structures, which are commonly analysed for damage detection, are affected by changing environmental and operational conditions, and most notably are subjected to bilinear effects from changing ambient temperature conditions. Therefore, damage detection in structures during the past decade has focused on eliminating the effects of these changing environments that affect the vibration properties of the structures. Several methods have been proposed in the literature to tackle the non-linear effects from changing environments. However, these methods can only analyse systems (e.g. natural frequency–environmental and operational system) that have an incremental change in relationship; they cannot model the bilinear effects from the changing temperature conditions, which may lead to false alerts. Hence, a damage detection method is proposed in this paper to tackle the piecewise effects from changing temperature conditions. The method makes use of a Gaussian mixture model to separate the different effects acting on the structures and uses principal component analysis for data processing. The method is applied to the Z24 Bridge, in Switzerland, which was subjected to bilinear effects from changing temperature conditions. The results obtained demonstrate that the proposed method successfully takes into account the piecewise effects to indicate the presence of damage.

This paper presents two-dimensional (2D) and three-dimensional (3D) numerical simulations of a half-scale geosynthetic reinforced soil (GRS) bridge abutment during construction and bridge load application. The backfill soil was characterized using a nonlinear elastoplastic model that incorporates a hyperbolic stress–strain relationship and the Mohr–Coulomb failure criterion. Geogrid reinforcements were characterized using linearly elastic elements with orthotropic behavior. Various interfaces were included to simulate the interaction between the abutment components. Results from the 2D and 3D simulations were compared with physical model test measurements from the longitudinal and transverse sections of a GRS bridge abutment. Facing displacements and bridge seat settlements for the 2D and 3D simulations agree well with measured values, with the 2D-simulated values larger than the 3D-simulated values due to boundary condition effects. Results from the 3D simulation are in reasonable agreement with measurements from the longitudinal and transverse sections. The 2D simulation can also reasonably capture the static response of GRS bridge abutments and is generally more conservative than the 3D simulation.

The influence of backfill type and material properties on the performance of field-scale geosynthetic reinforced soil (GRS) abutment models is investigated. Two alternative types of backfill as recommended in the Federal Highway Administration (FHWA) guidelines (called open-graded and well-graded) were used to build two field-scale model abutments and compare their load-bearing performance under a loading beam. Results are presented and discussed relative to the loading beam settlement, facing deformation and reinforcement strains. The well-graded backfill was found to result in smaller beam settlements and facing lateral deformations, especially at smaller loads that were comparable to service load levels. However, it was significantly faster and easier to compact the open-graded aggregate to the unit weight recommended in the guidelines. Nevertheless, performances of both abutment models were found to be satisfactory relative to the limiting requirements on the beam settlement and facing deformations at service load levels.

Improving the weight restrictions on weight-restricted bridges can make transportation networks more suitable for economic development; however, revenue shortfalls or institutional policy gaps can impede certain types of bridge improvements. Weight-restricted bridges that are not located on high-traffic-volume routes do not qualify for North Carolina State bridge improvement programs and funding targeted for improving weight restrictions. As a result, bridges that are critical nodes in North Carolina’s commerce freight network may not receive dedicated sources of funding for improvements or replacements that add value and long-term viability to the freight network. This study develops a novel process for identifying and prioritizing weight-restricted bridges critical to commerce freight. Bridge criticality is evaluated from two perspectives using a Geographic Information System (GIS) travel model to predict truck routes. Bridges traversed in the travel model receive scores based on the count of modeled traversals and the cost of modeled detours. Scores are weighted by the trucking intensity of traversals and the distance from traversed bridges to route origins. This process offers an objective system-wide evaluation of weight-restricted bridges that can be used to inform bridge improvements and replacement projects that fall outside of dedicated funding prioritization processes. A targeted validation of final bridge scores based on local stakeholder input should be considered to confirm the modeled criticality scores.

In this experimental study, the temporal development of local scour is studied around semi-circular end bridge abutments under quasi-unsteady clear-water flow conditions in a rectangular sediment channel. A step-wise hydrograph of 6 h duration is used in the experiments. Six different abutment lengths having constant width, with uniform sand as bed material, were tested for three different successive flows – each applied continuously for 2 h. Bathymetry of the bed level was measured around the abutment every 15 min with the help of a measurement device to observe temporal development of the local scour around the semi-circular end abutment. Effects of the abutment length, flow intensity and time on the scour depths around semi-circular end bridge abutments, along with those at the front, upstream and downstream faces of the abutment, are also investigated and discussed. It is shown that the maximum scour depth always occurs at the front noses of the abutments compared with those at the upstream and downstream noses. A dimensionless empirical formula is derived to predict the scour depth at the front nose of the abutment as a function of related parameters. The results reveal that flow intensity is the most critical parameter in scour development.

Graph processing has become an important part of various areas of computing, including machine learning, medical applications, social network analysis, computational sciences, and others. A growing amount of the associated graph processing workloads are dynamic, with millions of edges added or removed per second. Graph streaming frameworks are specifically crafted to enable the processing of such highly dynamic workloads. Recent years have seen the development of many such frameworks. However, they differ in their general architectures (with key details such as the support for the concurrent execution of graph updates and queries, or the incorporated graph data organization), the types of updates and workloads allowed, and many others. To facilitate the understanding of this growing field, we provide the first analysis and taxonomy of dynamic and streaming graph processing. We focus on identifying the fundamental system designs and on understanding their support for concurrency, and for different graph updates as well as analytics workloads. We also crystallize the meaning of different concepts associated with streaming graph processing, such as dynamic, temporal, online, and time-evolving graphs, edge-centric processing, models for the maintenance of updates, and graph databases. Moreover, we provide a bridge with the very rich landscape of graph streaming theory by giving a broad overview of recent theoretical related advances, and by discussing which graph streaming models and settings could be helpful in developing more powerful streaming frameworks and designs. We also outline graph streaming workloads and research challenges. ISSN:1045-9219 ISSN:1558-2183 ISSN:2161-9883

In this paper, the Difference of Seismic Response across Different Spans (DSR) in the longitudinal distribution of High-Speed Railway Multi-spans Simply Supported Bridge (HSRSB) under longitudinal earthquake excitation is investigated, and an evaluation method which can intuitively reflect the difference of seismic response is proposed. A feasible way to strengthen the connection stiffness between adjacent girders is proposed to control DSR. The rationality of the finite element model used is verified by comparing the numerical results with the experimental ones, showing a satisfactory agreement. Comparing the seismic response of a bridge model considering the subgrade-track constraints (BCTM) and a bridge model without subgrade-track constraints (BWTM), it is found that the DSR in the longitudinal distribution causes some new disadvantages, which are neglected in BWTM. The BCTM considering DLC generates a model called BCDM. The effect of the number of span on DSR are studied based on BCDM. The analysis of this model showed that DLC suppresses the DSR and reduces the seismic response of most bridge components. It also transfers the seismic disadvantage from the bridge part to the subgrade-track structure. As it is more convenient and cost-effective to repair the base plate of the subgrade than the bridge components after earthquake seismic event, this disadvantage transfer is in favor of forming a new anti-seismic system that subgrade-track structure is used to protect the bridge part.

Various strands of work have explored how spatial proximity helps (metaphorically) bridge barriers to resource mobilization and foster knowledge transfer. However, much of that work takes spatial connectedness as a given. We argue that spatial connectedness is a distinct construct that affects the extent to which spaces are not just proximate but are actually able to link people, ideas, resources, and knowledge together. We explore one such source of connectedness—physical (not metaphorical) bridges. We find that the opening of newly built bridges enhances startup founding in the local geographic community. Beyond their impact on startup founding, newly built bridges also influence the organizing process for such ventures. This includes a positive impact on the entry of prospective founders into entrepreneurship and an increase in the number of early-stage investors. The subsequently founded ventures are also more likely to engage in recombination and to cross industry boundaries. We explore scope conditions around industry and connective heterogeneity. We also test for robustness to various modeling approaches. The discussion highlights contributions of these findings to the study of entrepreneurship, as well as of organizations and the institutional fields in which they operate.

In this paper, we define soft union near-ring on a soft set by using soft sets, inclusion relation and union of sets. This new notion functions as a bridge among soft set theory, set theory and near-ring theory. We then derive its basic properties and investigate the relationship between soft intersection near-ring and soft union near-ring. Furthermore, we obtain some analog of classical near-ring theoretic concepts for soft union near-ring and give the applications of soft union near-ring to near-ring theory. © 2022 World Scientific Publishing Company.

Knowledge graph builds the bridge from massive data generated by the interaction and communication between various objects to intelligent applications and services in Internet of Things. The graph representation learning technology represented by graph neural network plays an essential role in the understanding and reasoning of the knowledge graph with complicated internal structure. Although they are capable of assigning different attention weights to neighbors, the graph attention network and its variants are inherently flawed and inadequate in modeling high-order knowledge graphs with high heterogeneity. Therefore, we propose a novel multi-relational graph attention network framework in this paper for knowledge reasoning over heterogeneous graphs by employing tensor and tensor operations. Specifically, we formulate the general high-order heterogeneous knowledge graph firstly. Then, the tensor graph attention network (TGAT), composed of three components: heterogeneous information propagation, multi-modal semantic-aware attention, and knowledge aggregation, is developed to simulate rich interactions between mixed triples, entities, and relationships when aggregating local information. What’s more, we utilize Tucker model to compress the parameters of TGAT and further reduce the storage and calculation consumption of the intermediate calculation process on the premise of maintaining the expressive power. We conduct extensive experiments to solve the link prediction task on four real-world heterogeneous graphs, and the results demonstrate that the TGAT model proposed in this paper remarkably outperforms state-of-the-art competitors and improves the hits@1 accuracy by up to 7.6%.

To ensure the structural safety and normal operation of a cable-stayed bridge in China (Rainbow Bridge), cables were replaced and construction monitoring and control were conducted. In the process of cable replacements, the cable force and girder elevation were monitored and the distribution of cable force was adjusted according to the construction monitoring results to improve the structural force and increase the safety reserve of the structure. In the process of monitoring the cable force, the difference between the measured cable force and the design cable force was 0.4–4.4%. After adjusting the cable force, the difference between the measured cable force and the design cable force was less than 2%, and the change in the cable force was uniform, meeting the original design requirements. In the monitoring process of the main girder elevation, the elevation was increased by a maximum of 0.054 m. After completing cable adjustment, the main girder elevation was increased by 0–5 mm. This elevation was more reasonable and met the design requirements.

Xinglinpu Bridge was built on the S3801 freeway in 2019 in preparation for the winter Olympics in Beijing, China. It is a cable-stayed steel bridge with pylons in the shape of flower baskets. Using Xinglinpu Bridge as a case study, a systematic approach to the dimensional quality assessment of complex bridges using a combination of three-dimensional (3D) point clouds obtained by terrestrial laser scanning (TLS) and unmanned aerial vehicle (UAV) surveys is proposed in this paper. The currently available methods for dimensional quality assessment of complex bridges rely largely on manual inspection and contact-type measurement devices, which are time consuming and costly. To overcome these limitations, this paper presents a framework for dimensional quality assessment composed of three parts: scanning schemes for TLS and UAV, scanning implementation and measurement of geometric dimensions. The results of configuration detection verified the high-quality construction of Xinglinpu Bridge, although millimetre-scale differences were obtained between the point clouds and the design value. The potential and limitations of 3D laser scanning for assessing the quality of complex bridges are discussed.

Several provinces in Canada have modified the live load model specified in national bridge design codes to account for locally permitted trucks. Manitoba similarly introduced a live load model for the design of provincial bridges in accordance with AASHTO LRFD, the Modified HSS-25. This article presents truck weight datasets and methods used to develop Manitoba-specific live load statistics to conduct a reliability analysis for three typical simply supported structure types: precast prestressed concrete box girder, precast prestressed concrete I-girder and steel girder. The average reliability indices ranged from 4.69 to 4.95 with respect to the AASHTO LRFD live load statistics used to calibrate the code and 4.65 to 5.04 with respect to the Manitoba statistics. The results demonstrate a level of safety that exceeds the code requirements, indicating that structures designed to the HSS-25 potentially possess the structural capacity to withstand increased vehicular load effects for the considered bridge types.

The River Dee Bridge is a 270 m long concrete box girder bridge constructed as part of the Aberdeen Western Peripheral Route. The detailed design commenced in 2014, with construction finishing in late 2018. The bridge has a mainspan of 120 m and was built using the balanced cantilever construction method. This paper focuses on the design challenges encountered during the detailed design of this structure, particularly associated with the tight geometrical constraints imposed by environmental and aesthetic considerations on the foundations and the superstructure. The post-tensioned tendon design, which was particularly challenging for this relatively narrow and shallow box section, is also discussed.

This paper deals with the modeling and estimation of the sociological phenomena called echo chambers and segregation in social networks. Specifically, we present a novel community-based graph model that represents the emergence of segregated echo chambers as a Markov bridge process. A Markov bridge is a one-dimensional Markov random field that facilitates modeling the formation and disassociation of communities at deterministic times which is important in social networks with known timed events. We justify the proposed model with six real world examples and examine its performance on a recent Twitter dataset. We provide model parameter estimation algorithm based on maximum likelihood and, a Bayesian filtering algorithm for recursively estimating the level of segregation using noisy samples obtained from the network. Numerical results indicate that the proposed filtering algorithm outperforms the conventional hidden Markov modeling in terms of the mean-squared error. The proposed filtering method is useful in computational social science where data-driven estimation of the level of segregation from noisy data is required.

Bridge management professionals need effective tools to help guide the decision making process and maintain quality infrastructure in a region. Using logistic regression for a novel binary response defined by at-risk and not-at-risk bridges based on their existing overall condition scores, the probability of a bridge being at risk is expressed in terms of the primary bridge factors age, load, the type of construction material and structural design and conditions of the deck, superstructure and substructure. These estimated probabilities multiplied by specified consequence values are used to introduce the risk classes and their ranks. Employing the method for training and validating sets of sizes 13 540 and 3385 in 2017 and 13 481 and 3370 in 2018 data in the National Bridge Inventory (NBI) Indiana, a statistically significant model is established containing the age, load and conditions of both superstructure and substructure. Moreover, at-risk bridges are identified from Indiana NBI data in both years and for a subset from Connecticut in 2017. The innovative bridge-ranking tool prioritises bridges for maintenance purposes such as replacing or repairing and hence efficiently guides the management in the decision making process for capital expenditures and perhaps for predicting the missing overall bridge condition.

This paper sets out the challenges from the perspective of the designer associated with the construction of the River Dee Bridge built by the balanced cantilever method. The importance of managing the construction sequence and its impact on both the design and programme are discussed. Monitoring and managing the loads in the temporary works were crucial to ensuring the stability of the structure. The issues associated with the temporary jacking system and the monitoring adopted are also considered.

Veno-arterial membrane oxygenation (VA-ECMO) can be used as a rescue therapy for patients in refractory cardiogenic shock. While there is experience as a bridge-to-transplant and bridge-to-ventricular assist device in the heart failure population, there are not reports of its use as a bridge to definitive valvular intervention. Here we present a case of VA-ECMO as a bridge to transcatheter mitral valve-in-valve (TMVIV) with a Sapien aortic prosthesis (Edwards Life Sciences, Irvine, CA).

With the increasing demand of users for personalized social services, social recommendation (SR) has been an important concern in academia. However, current research on SR universally faces two main challenges. On the one hand, SR lacks the considerable ability of robust online data management. On the other hand, SR fails to take the ambiguity of preference feedback into consideration. To bridge these gaps, a deep learning-embedded social Internet of Things (IoT) is proposed for ambiguity-aware SR (SIoT-SR). Specifically, a social IoT architecture is developed for social computing scenarios to guarantee reliable data management. A deep learning-based graph neural network model that can be embedded into the model is proposed as the core algorithm to perform ambiguity-aware SR. This design not only provides proper online data sensing and management but also overcomes the preference ambiguity problem in SR. To evaluate the performance of the proposed SIoT-SR, two real-world datasets are selected to establish experimental scenarios. The method is assessed using three different metrics, selecting five typical methods as benchmarks. The experimental results show that the proposed SIoT-SR performs better than the benchmark methods by at least 10% and has good robustness.

Changes in the size and weight regulations for trucks have been used to improve their productivity, safety, and operational performance in Canada. In response to these changes, bridge design codes undergo modifications to envelop the potential range of trucks in operation. A five-decade timeline is presented to: (i) document how bridge codes and their live load models have evolved, with a focus on the Manitoba-specific HSS-25 truck; and (ii) discuss how responsive the bridge design codes have historically been to changes in truck size and weight regulations. While at times bridge codes are released in conjunction with expected regulation changes, there is often delay in the issuance of those codes. Assessments of the current truck fleet, which now includes long combination vehicles (LCVs), may be a consideration for future bridge live load models.

The notion of situational analysis has different origins. The most relevant, historically, are Max Gluckman's ethnography of a conventional crowd, that met at the “inauguration of a bridge in Zululand,” and Goffman's innovative ecology of public encounters and gatherings, as exposed in Behavior in Public Places (1963). In the first case, the situational analysis was highlighting the link between face to face relationships and exchanges, and the macroprocesses of the colonial society in Rhodesia; in the second case, it intended to discover an “interactional order,” meaningful in itself, “loosely coupled” with social structures. Both meanings can be found in the literature on social movements. Keywords: collective behavior; protests; public participation; resistance; strikes

Plug-in electric vehicles charger is preferred to cover an ultra-wide battery voltage range with the vehicle-to-grid capability. Conventional bidirectional resonant dc/dc converters suffer from the contradiction among wide voltage gain range, squeezed dc-link voltage span, and narrow switching frequency band. To solve the issue, this manuscript proposes a novel H5-bridge based bidirectional CLLC converter. By configuring the switch pattern, the H5-bridge can form the modes of single half bridge, dual half bridge, half full bridge, and dual full bridge, respectively. Correspondingly, six gain curves can be derived. Combined with the variable dc-link framework, the converter constrains the switching frequency in the vicinity of the resonant frequency with optimal efficiency. The converter achieves an ultra-wide battery voltage range with a squeezed dc-link span. A bidirectionally synchronous rectification method is proposed to improve the efficiency further. To verify the proposed concept, a 1-kW rated prototype with 320420V dc-link is built and tested. It validates the battery voltage 55420V for charging and 230420V for discharging. Zero voltage turning-on and zero current turning-off are achieved in the rectifying MOSFETs. The prototype exhibits 98.04% peak efficiency and good overall efficiency performance.

This study is aimed at improving the seismic stability of bridge abutments. To study the effects of the combined use of a block of expanded polystyrene (EPS) and geogrid, a series of 1 g shaking table tests were conducted on a reduced-scale model of a cantilever-type bridge abutment and its backfill soil. The experiment results indicated that the base sliding and tilting of the wall can be further reduced by partly replacing the backfill soil with blocks of EPS, in combination with the use of the middle-height geogrid. Moreover, the relative settlement of the backfill soil at the interface with the wall could be reduced by the combined use of EPS and geogrid. Furthermore, the resultant normal force and rotational moment acting on the wall from the backfill soil during excitation also became small for the reinforced wall with both EPS and geogrid.

In this work, we aim at building a bridge from coarse behavioral data to an effective, quick-response, and robust behavioral model for online identity theft detection. We concentrate on this issue in online social networks (OSNs) where users usually have composite behavioral records, consisting of multidimensional low-quality data, e.g., offline check-ins and online user-generated content (UGC). As an insightful result, we validate that there is a complementary effect among different dimensions of records for modeling users' behavioral patterns. To deeply exploit such a complementary effect, we propose a joint (instead of fused) model to capture both online and offline features of a user's composite behavior. We evaluate the proposed joint model by comparing it with typical models and their fused model on two real-world datasets: Foursquare and Yelp. The experimental results show that our model outperforms the existing ones, with the area under the receiver operating characteristic curve (AUC) values 0.956 in Foursquare and 0.947 in Yelp, respectively. Particularly, the recall (true positive rate) can reach up to 65.3% in Foursquare and 72.2% in Yelp with the corresponding disturbance rate (false-positive rate) below 1%. It is worth mentioning that these performances can be achieved by examining only one composite behavior, which guarantees the low response latency of our method. This study would give the cybersecurity community new insights into whether and how real-time online identity authentication can be improved via modeling users' composite behavioral patterns.

In recent years, the designers of long girder bridges in seismic areas have frequently opted for a continuous deck. One implication of this choice is that in many instances bridge abutments are called upon to carry large seismic forces, engaging the dynamic response of the soil–abutment system. To deal with this problem, this paper describes the formulation of a novel one-dimensional, inertial macroelement for simulating the dynamic behaviour of bridge abutments. The non-linear force–displacement relationship is characterised by a multi-surface plasticity model using a rigorous thermodynamic approach. The plastic response of the model is bounded by the ultimate capacity of the soil–abutment system that includes dissymmetry of the soil response in active and passive loading directions, while inertial effects transferred by the near-field approach embankment are simulated through appropriate participating masses in the macroelement formulation. The paper describes a straightforward calibration procedure of the proposed macroelement for horizontal, longitudinal loading of the abutment. The macroelement has been incorporated into a simplified, global, finite-element model of a multi-span girder bridge and validated through comparisons with results from a full three-dimensional (3D) dynamic time domain analysis under seismic loading. The inertial macroelement predictions of abutment deformations, axial deck loads and pier reaction forces are in very good agreement with the 3D soil–structure interaction model, and are achieved at much lower computational costs. The proposed inertial macroelement represents a significant improvement over existing simplified models based on linear response of the soil–abutment system.

The aim of this paper is to analyze the influence of adding serial inductance in AC side of the 3ph -6 pulse bridge rectifier on the reduction of harmonic distortion rate. A simulated model with serial inductance was analyzed. The 3-phase 6-pulse diode bridge rectifier was chosen because it corresponds to the operation of the 6-pulse thyristor bridge rectifier at maximum load (while keeping the angle α = 0). Both the total harmonic distortion (THDi) and the power factor (PF) for the circuit have been measured. The results obtained of the THDi has been recorded for four values of serial inductance and results was compared with the (IEEE 519-1992) standard. Comparison results indicates that for values of inductive reactance (Xi) up to 67% cause a reduction of THDi which is above the standard values, while for (Xi) more than 67% cause a reduction in THDi within the acceptable standard level. Analyzing of results prove that the adding of serial inductance at the AC side leads to good reduction in harmonic distortion rate, but with some reduction in power factor value, which results in some energy losses.

Consistent application of neurotropic factors is necessary in peripheral nerve regeneration, yet challenging to achieve. Here we used a novel neurotropic factor controlled release system consisted of fibrin, fibronectin and hydrogel to slowly release two neurotrophic factors. At the same time, physiological saline and reverse nerve suturing were used as negative and positive control. A year after surgery, animals which were treated by neurotrophic factor slow release system achieved far better neural regeneration and myelination, as well as superior recovery of hindfoot than the negative control group. In the meanwhile, the results in the experimental group are still inferior to the nerve allograft group. In can be concluded from those results that, consistent releasing of neurotrophic factors can significantly promote long peripheral nerve regeneration, but still short of achieving the results same as the gold standard of autologous nerve grafting.

The aim of this work is to estimate the seismic reliability of a simple typical two-span lifeline base-isolated bridge designed to behave essentially elastic or as per the Canadian Highway Bridge Design Code, for seven localities in Quebec. Two limit states are considered for possible failure due to unacceptable damage: flexure at the pier-base and displacement within the seismic isolation systems (SIS). The main problem random variables considered and modeled are seismic hazard, temperature, pier base dimensions, and material mechanical properties. The Monte Carlo method was used to evaluate the probability of failure and the reliability of each limit state. Preliminary results reveal that notwithstanding the large temperature and seismic hazard variabilities between the seven sites in Quebec, the global bridge reliability indices are almost uniform, approximately 3.45 ± 0.02. Furthermore, the security factor (i.e., 1.25) on the SIS displacement capacity results in reliability indices for SIS displacement that are not levelled with the flexural reliability indices and requires further examination and consideration.

A 415 m long three-span steel railway bridge was built over the tidal Hooghly River near Kolkata in India in 2016. The new Sampreeti Bridge is just 22 m downstream from the 1887 Jubilee Bridge it replaces, which is due to be moved to an outdoor engineering heritage museum. Despite 130 years of engineering advances, the forces of nature proved equally challenging to overcome. As happened previously, a pier caisson was swept away by monsoon rains – twice – and accommodating dynamic loading required adoption of the latest bearing technology.

The Hong Kong–Zhuhai–Macao Bridge has a total length of 55 km. One of the greatest technical challenges is an immersed tunnel section stretching over 5.664 km and consisting of 33 prefabricated units (tunnel elements). The tunnel is buried 22 m below the seabed, and is therefore subjected to a significant overburden pressure (at a level of ∼100 kPa) during its whole service life. Conventional tunnel elements are either monolithic or segmented. Monolithic elements act like rigid beams, whereas segmented elements behave like a flexible chain. Under this high level of overburden pressure, the tunnel is liable to problems such as concrete cracking, joint opening and leaking. A novel solution for the semi-rigid (structural) system was proposed and adopted. The central idea is to use compressive force and frictional force at the vertical faces of the segment joints to improve the integrity of the longitudinal structure of the tunnel elements. This paper reviews the concept, design and in situ post-construction observations of this semi-rigid system.

This article investigates the employment effect of short-time work in the Netherlands during the Great Recession (2009–2011). Short-time work was introduced during the period as a special arrangement with the aim of reducing unemployment hikes by offering firms the possibility of adjusting the working time of specialised workers rather than adjust the size of their workforce. The authors focus on the effect of short-time work at the individual level of the worker and study whether short-time programme participants in surviving firms had a lower job turnover rate and transition rate to unemployment compared to workers who did not participate in the programme. Furthermore, the authors study whether the flexibility policies of the firm had a substantial influence on the effectiveness of short-time work in protecting workers from unemployment. Specifically, they investigate whether the effect of short-time work is related to the intensiveness of its use by the firm and the extensiveness of the use of external flexibility arrangements – i.e. temporary contracts and temporary agency workers – by the firm. For this purpose, the authors apply a discrete-time survival model using a unique dataset with monthly register data from Statistics Netherlands. Participants in the short-time work programme are compared with non-participant workers from firms that used short-time work and workers from firms that did not make use of the programme. The findings indicate that, in surviving firms, short-time work had a positive effect: the risk of unemployment and job separation is, in most cases, lower for short-time work participants than non-participants. Short-time work is most effective in protecting workers from unemployment in firms that extended the use of the programme to many workers and for a relatively small number of hours, and that made either moderate use of temporary agency workers or extensive use of fixed-term contracts.

BACKGROUND: Travel distance to medication treatment for opioid use disorder (OUD) is a challenge for many patients, but little is known about how distance is associated with medication treatment utilization. This study examines the association between distance to the nearest physician waivered to prescribe buprenorphine and patient-level buprenorphine treatment among West Virginia Medicaid expansion enrollees with diagnosed OUD. METHODS: We conducted a cross-sectional spatial analysis with 2016 Medicaid claims data, separately examining individuals living in metropolitan and non-metropolitan areas. We calculated the driving distance from the centroid of patients’ residential ZIP codes to the street address of the nearest waivered physician derived from the 2015 Drug Enforcement Administration listing. Regression models examined the association between distance and initiation and duration of buprenorphine (among those initiating). RESULTS: We focused on 8,008 individuals with OUD in 2016. The nearest waivered prescriber in metropolitan areas was an average of 7.13 miles away from patients’ residential ZIP codes and 14.54 miles in non-metropolitan areas. The providers they actually visited were a mean of 33.63 miles away in metro areas and 46.36 in non-metropolitan areas. In multivariable analyses, compared to those living 20 miles from a waivered physician was associated with −32.13 fewer days of treatment (95% CI: −57.86, −6.40) in metro areas and −16.70 fewer days in non-metro areas (95% CI: −32.32, −1.08). CONCLUSIONS: Longer travel distance to buprenorphine treatment is associated with shorter duration of care that is likely to be clinically meaningful.

Tetrasilabicyclo[1.1.0]but-1(3)-enes, compounds containing an Si=Si double bond with an inverted geometry, have recently emerged as a new class of stable π-electron systems of silicon. Herein, we r...