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Historical masonry mosques are a cultural heritage that is actively used today and should be transferred to the future in safe. These structures, which generally have a masonry load-bearing system, have been observed to be seriously damaged in different earthquakes. Many studies are carried out to determine the earthquake behavior of historical masonry mosques. However, reasons such as various material properties, failure mechanisms, uncertain geometry and loading conditions make it difficult to determine the seismic behavior of these structures. In this study, the finite element model of Konya Karapınar Sultan Selim Mosque was created using different two material properties (E=750fc and E=200fc). In the finite element models, time history analyzes were carried out using 5 different ground motions. As a result of dynamic analyses, different collapse mechanisms of the mosque were investigated. In addition, the earthquake performance limits of the mosque based on displacement were determined and compared with the codes, guidelines and literature recommendations. The effect of the elasticity modulus on the performance limits of the mosque has been examined. [ABSTRACT FROM AUTHOR]

Dynamic calculations of train crossing of railway bridges must be carried out in Europe in accordance with current valid standards for both new and existing bridges. The high‐speed load model (HSLM) trains to be used are defined in the Eurocode, denoted as HSLM‐A1 to ‐A10. In the near past, the results gained from these dynamic calculations of train crossing have shown, that the current valid HSLM model trains do not cover the bridge vibration response level for certain real operating trains. It turned out that the application of the HSLM‐A trains might lead to an unsafe design of new railway bridges and destabilization of the ballast layer may occur, leading to safety critical track position defects and eventually to train derailments. Hence, in 2019 the consortium TU Darmstadt, KU Leuven, Austrian Institute of Technology and REVOTEC was commissioned by the German Federal Railway Authority to develop a completely new European high‐speed train load model for dynamic calculations of railway bridges that should account for almost all current running operating trains in the European railway network. The project ended in June 2023 and this paper presents the steps carried out to develop the high‐speed train load model, denoted as HSLM‐C, and the results of validation calculations considering more than 300 existing railway bridges of different construction type. [ABSTRACT FROM AUTHOR]

Qualitative and quantitative assessments evaluate the structural vulnerability of liquid storage tanks. Liquid storage tanks are typically constructed and operated in areas with hard soils to minimize confining influences. However, many of these critical structures are in coastal areas with soft soils. The research conducted in this study entails the utilization of the finite element method accurately model the seismic behavior of a semi-buried concrete tank under various conditions, including changing water levels and soil properties. The study examines fluid–structure and soil–structure interactions through dynamic analyses of the rectangular semi-buried tank and comparing its different parameters. It also identifies sensitive areas where there is a probability of liquid leakage in storage tanks. The modeling is compared with the qualitative evaluation in the Japanese vibration capability diagnosis table. The results show that the tensile stress in the wall adjacent to the expansion joint is greater than the corresponding stress in the wall in all cases. In the dynamic analyses of the soil types, the pressure on the surface increases with increasing water height. A comparison of the quantitative and qualitative evaluation results shows the possible leakage of the tank in soft soil in the expansion joint. [ABSTRACT FROM AUTHOR]

This paper proposes a control technique for a large-scale grid-connected photovoltaic (PV) plant that maintains the connection of an inverter to the grid voltage under different types of faults, while injecting a reactive power to accommodate the required grid connection. This control strategy is suggested to improve the low-voltage ride-through (LVRT) capability of grid-connected PV power generation plants. A 20 MW solar PV power plant is modeled and simulated using Matlab/Simulink. The power plant is composed of 10 parallel groups of arrays with a power rating of 2 MWp. The solar PV arrays are connected to a medium-voltage side-rated 22 KV to the utility grid. A dynamic analysis of the grid-connected large-scale solar PV power plant is introduced. This analysis is accomplished in order to determine the impact of three-phase short-circuits at the point of common-coupling (PCC), where the solar PV power station is connected to ensure a practical voltage level by injecting active and reactive power. The reactive power support allows for faster restoration of voltage values at the PCC. When subjected to transient disturbances, the stability of the studied system relies on both the type of the disturbance and the initial operating situation. The disturbance may be either small, resulting from electrical load changes, or large, such as from a transmission line short-circuit (fault) and significant generator loss. [ABSTRACT FROM AUTHOR]

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• A novel framework to define limit states for the seismic fragility assessment of circular tunnels is introduced. • Nonlinear static pushover analyses are employed to examine the seismic capacity of tunnels. • Nonlinear dynamic analyses are employed to examine seismic demand of tunnels. • The proposed framework is applied to 27 ground-tunnel configurations. • PGA -based fragility functions are derived, which are compared with the existing fragility curves. This paper introduces a novel framework to define limit states for the seismic fragility assessment of circular tunnels in soil. A numerical framework is developed for this purpose, focusing on the response of tunnels subjected to ground seismic shaking in the transverse direction. New limit states are defined based on the ovaling deformation of the tunnel, corresponding to different levels of liner stiffness degradation caused by seismic shaking. The latter is evaluated via nonlinear static pushover analyses of the examined ground-tunnel configurations. Nonlinear dynamic analyses are performed to evaluate the demand of examined tunnels and develop Probabilistic Seismic Demand Models (PSDMs). The uncertainties related with the definitions of capacity and demand are thoroughly evaluated based on the results of the nonlinear static pushover and dynamic analyses, respectively. The proposed framework is applied to a 6 m diameter circular tunnel embedded in uniform clayey soil deposit at a burial depth of 15 m. Various assumptions are made regarding the thickness and mechanical properties of the liner and the soil, leading to the investigation of 27 ground-tunnel configurations. A suite of ground motions is selected to perform dynamic analyses of each examined configuration. Based on the results of the analyses new PSDMs and PGA -based fragility functions are derived. Comparisons of the proposed fragility curves with existing, empirical, and analytical fragility curves for tunnels, reveal differences, which in some cases are significant and are mainly attributed to the different definitions of Engineering Demand Parameters (EDPs) and limit states between the compared curves, as well as to different assumptions in the analytical frameworks proposed by various studies. The proposed framework may be applied to other ground-tunnel configurations to develop fragility functions for a more rigorous risk and resilience assessment of these types of systems. [ABSTRACT FROM AUTHOR]

Minarets are slender and tall structures that are built from different types of materials. Modern materials are also starting to be used in such structures with the recent developments in material technology. The seismic vulnerability and dynamic behavior of minarets can vary, depending on the material characteristics. Within this study's scope, thirteen different material types used in minarets in Türkiye were chosen as variables. A sample minaret model was chosen as an example with nine different heights to reveal how material characteristic change affects seismic and dynamic behavior. Information and mechanical characteristics were given for all the material types. Natural fundamental periods, displacements, and base shear forces were attained from structural analyses for each selected material. The empirical period formula for each material is proposed using the obtained periods, depending on the different minaret heights taken into consideration. At the same time, fundamental natural periods for the first ten modes and 13 different types of materials used in the study were estimated with the established Artificial Neural Network (ANN) model. The real periods from the experimental analyses were compared with the values estimated by the ANN using fewer parameters, and 99% of the results were successful. In addition, time history analyses were used to evaluate the seismic performance of the minaret (three different materials were considered). In this specific case, the acceleration record from the 2011 Van (Eastern Turkiye) earthquake (Mw = 7.2) was taken into consideration. Performance levels were determined for the minaret according to the results obtained for each material. It has been concluded that material characteristics significantly affect the dynamic and seismic behavior of the minarets. [ABSTRACT FROM AUTHOR]

This paper presents an important improvement in seismic design of structures based on the application of the Theory of Plastic Mechanism Control (TPMC). TPMC was originally proposed in the '90s requiring an iterative algorithm and upgraded in 2015 leading to the so‐called closed form solution. In the recent years, TPMC has shown its value as an effective design procedure which can be applied to any structural typology. Moreover, it has been used as a code competitor design tool in important RFCS founded research projects confirming its effectiveness, simplicity, and suitability to any structural typology. The aim of the TPMC is the design of structures able to exhibit at collapse a global type mechanism. The TPMC was originally based on the extension of the kinematic theorem of plastic collapse to the concept of mechanism equilibrium curve, working in the α−δ$\alpha - \delta $ plane (being α the multiplier of the seismic forces and δ the top sway displacement). The novelty of this work is improvement of the design procedure by working in the α−θ$\alpha - \theta $ plane, being θ the plastic rotation. This new TPMC approach, namely TPMC(θ), has demonstrated to be as reliable as the former approach, thus leading to structures able to develop a collapse mechanism of global type but with the optimization of the structure using lighter columns. The effectiveness of the new procedure has been confirmed by both pushover and dynamic non‐linear analyses. [ABSTRACT FROM AUTHOR]

Code response spectrum models, which are used widely in the earthquake-resistant design of buildings, are simple to apply but they do not necessarily represent the real behavior of an earthquake. A code response spectrum model typically incorporates ground motion behavior in a diversity of earthquake scenarios affecting the site and does not represent any specific earthquake scenario. The soil amplification phenomenon is also poorly represented, as the current site classification scheme contains little information over the potential dynamic response behavior of the soil sediments. Site-specific response spectra have the merit of much more accurately representing real behavior. The improvement in accuracy can be translated into significant potential cost savings. Despite all the potential merits of adopting site-specific response spectra, few design engineers make use of these code provisions that have been around for a long time. This lack of uptake of the procedure by structural designers is related to the absence of a coherent set of detailed guidelines to facilitate practical applications. To fill in this knowledge gap, this paper aims at explaining the procedure in detail for generating site-specific response spectra for the seismic design or assessment of buildings. Surface ground motion accelerograms generated from the procedure can also be employed for nonlinear time-history analyses where necessary. A case study is presented to illustrate the procedure in a step-by-step manner.

Qualitative and quantitative assessments evaluate the structural vulnerability of liquid storage tanks. Liquid storage tanks are typically constructed and operated in areas with hard soils to minimize confining influences. However, many of these critical structures are in coastal areas with soft soils. The research conducted in this study entails the utilization of the finite element method accurately model the seismic behavior of a semi-buried concrete tank under various conditions, including changing water levels and soil properties. The study examines fluid–structure and soil–structure interactions through dynamic analyses of the rectangular semi-buried tank and comparing its different parameters. It also identifies sensitive areas where there is a probability of liquid leakage in storage tanks. The modeling is compared with the qualitative evaluation in the Japanese vibration capability diagnosis table. The results show that the tensile stress in the wall adjacent to the expansion joint is greater than the corresponding stress in the wall in all cases. In the dynamic analyses of the soil types, the pressure on the surface increases with increasing water height. A comparison of the quantitative and qualitative evaluation results shows the possible leakage of the tank in soft soil in the expansion joint.

In this paper, the seismic behaviour and the strut retrofitting of the Mozaffarieh Timche in the historical covered Tabriz Bazaar is investigated. The Bazaar was added to the UNESCO World Heritage List in August 2010. Historical buildings are particularly vulnerable to seismic events because they were designed solely for gravitational loads without any consideration of seismic parameters. The study was carried out in three main steps, the first of which consisted of compression and three-point bending tests on the construction materials to determine their mechanical properties. Thereafter, a three-dimensional finite element model of the Mozaffarieh Timche was developed. Finally, numerical modelling and dynamic analyses were performed. The results revealed that neither the orthogonal walls nor the vaults have adequate resistance to lateral loads. Consequently, they need to be retrofitted in a suitable manner. To avoid collapse or wide crack patterns, two types of strengthening methods are proposed. Steel ties should be applied for reinforcing and for connecting walls to each other, and a spatial structure needs to be placed on the roof in order to control the large displacement of the vaults. The strengthened model showed an acceptable performance with regard to major earthquake excitation, with minimum change to the historic architectural view of the structure. [ABSTRACT FROM AUTHOR]

Minarets are slender and tall structures that are built from different types of materials. Modern materials are also starting to be used in such structures with the recent developments in material technology. The seismic vulnerability and dynamic behavior of minarets can vary, depending on the material characteristics. Within this study’s scope, thirteen different material types used in minarets in Türkiye were chosen as variables. A sample minaret model was chosen as an example with nine different heights to reveal how material characteristic change affects seismic and dynamic behavior. Information and mechanical characteristics were given for all the material types. Natural fundamental periods, displacements, and base shear forces were attained from structural analyses for each selected material. The empirical period formula for each material is proposed using the obtained periods, depending on the different minaret heights taken into consideration. At the same time, fundamental natural periods for the first ten modes and 13 different types of materials used in the study were estimated with the established Artificial Neural Network (ANN) model. The real periods from the experimental analyses were compared with the values estimated by the ANN using fewer parameters, and 99% of the results were successful. In addition, time history analyses were used to evaluate the seismic performance of the minaret (three different materials were considered). In this specific case, the acceleration record from the 2011 Van (Eastern Turkiye) earthquake (Mw = 7.2) was taken into consideration. Performance levels were determined for the minaret according to the results obtained for each material. It has been concluded that material characteristics significantly affect the dynamic and seismic behavior of the minarets.

The aim of this research is to study the dynamic behaviour of a real gantry crane subjected to the actions induced by the trolley and payload movement. A specific numerical procedure was developed and implemented in the finite element method in order to simulate different trolley movement modes on the crane's main beam. From the results, it is clear that the crane displacement, especially the longitudinal one, is strongly dependent on the acceleration both in the starting phase and in the stopping phase to which the trolley is subjected during its movement on the crane main beam. The last part of this research simulates the sudden stop of the trolley movement and subsequent payload swinging; in this case, the length of the rope that suspend the payload to the trolley has a fundamental role in the trend and maximum longitudinal crane displacement value.

Historical masonry arch bridges which might be vulnerable to natural disasters are important part of the cultural heritage. Natural disasters, especially earthquakes can inflict damage to these structural systems. This paper aims to investigate a comparison of the effects of near and far-fault ground motions on the seismic response of masonry arch bridges under different earthquakes. Kalender masonry arch bridge which is located in Ergani, Turkey is selected as a numerical model. For this purpose, three-dimensional finite element model of the bridge is generated with ANSYS finite element software with macro modelling approach. Seismic response of the bridge is assessed by means of time-history analyses. The near-fault and far-fault ground motions, which have approximately equal peak ground accelerations, of 1979 Imperial Valley, 1999 Chi-Chi, 1999 Kocaeli and 2010 Darfield earthquakes are considered for the analyses. Comparisons between maximum displacements, maximum and minimum stress, which were acquired from the dynamic analyses of the masonry bridge subjected to each fault effect, are obtained. The study demonstrates that far-fault ground motions are as important as near-fault ground motions and it can be used together with near-fault ground motion for further evaluation of such historical masonry bridges. [ABSTRACT FROM AUTHOR]

A simple jerk system with only one exponential nonlinearity is proposed and discussed. Dynamic analysis of the integer-order jerk system shows the existence of chaotic oscillations. A model for the fractional-order jerk system is derived. The Adomian decomposition method is used to analyse the fractional-order jerk system. Stability analysis of the fractional-order jerk system shows that chaotic oscillations exist in orders less than one and bifurcation analysis shows the range of fractional orders for periodic and chaotic oscillations. To show the randomness of the fractional-order jerk system, a pseudorandom number generator is designed and tested. The NIST-800-22 tests show that the proposed fractional-order jerk system is effective in showing randomness. Finally, an image hiding application to the audio data has been realized by using the developed RNG algorithm. The encrypted image is hidden by being embedded in the audio data, and then, on the receiver side, the data are recovered by taking the image data from the hidden audio file. [ABSTRACT FROM AUTHOR]

This paper focuses on the evaluation of the seismic performance of Cerere, the central sculpture of Bartolomeo Ammannati's Juno Fountain, currently located in Florence, at the Museum of Bargello. A 3D geometrical model based on a laser scanner survey has been obtained and employed to build the finite element model (FEM) used in the analyses. The seismic response of the sculpture has been checked by performing different dynamic analyses, applying three three-dimensional spectrum-compatible ground motions, and using different computer codes and assumptions. The considered numerical models differ from each other regarding the material behavior (linear and non-linear) and the connection between the statue and its pedestal. The obtained results reveal that this latter assumption affects very much the dynamic response of the system. The role played by the possible assumptions regarding the number of components constituting the seismic input and the amount of friction between the pedestal and the statue are also discussed. [ABSTRACT FROM AUTHOR]

Recent theoretical developments in the domain of strategic groups, specifically those related to cognitive groups and strategic group identity, seem to suggest that strategic group membership is likely to be relatively stable over time and that firms in a strategic group co-evolve. Yet appropriate data analytic approaches that use information about firms over time to identify stable strategic groups and their evolutionary paths have been lacking. To overcome such limitations, this research proposes a new clusterwise bilinear multidimensional scaling model that can simultaneously identify (1) the number of strategic groups, (2) the dimensions on which the strategic groups are based, and (3) the evolution of the strategy of these groups over time. Our discussion encompasses various alternative model specifications, together with model selection heuristics based on statistical information criteria. An illustration of the proposed methodology using data pertaining to strategic variables for a sample of public banks in the tristate area of New York, Ohio, and Pennsylvania across three time periods (1995, 1999, and 2003) identifies two underlying dimensions with five strategic groups that display very different evolutionary paths over time. Post hoc analysis shows pronounced differences in firm performance across the five derived strategic groups. This article concludes with a discussion of the implications of the findings, as well as potential future research directions. John Wiley & Sons, Ltd. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper conducts numerical studies on the response of a deep ocean rocket launching triceratops for five rocket launching cases at a water depth of 1055 m. It is observed that the relative response of the structure increases with the increase in the thrust force and moments; relative surge response of deck and buoyant legs are marginal compared to heave and pitch due to the ball and socket joint connecting the deck and the buoyant legs. Hence, the novel response characteristics offered by the ball joints are utilized for launching large rockets. As the launch varies from small to huge rockets, the variation in the tether tension is also increased. The Quadra-response spectrum for the launch shows the importance of the resonance condition under rocket launch. Parametric studies of varying sea states along with light air, moderate breeze, and strong breeze conditions were selected for the study. The worst scenario for a deck is observed under a strong breeze when large rockets are launched. The numerical analysis shows that the relative displacements due to the rocket launch depend on the environmental parameters and thus emphasize a holistic design approach incorporating the combined effects of wave, wind, and rocket. • Offshore triceratops is an ideal option for space launches. • Partial isolation inducted by ball joints enables desirable dynamic characteristics for such operations. • Ball joints restrain the transfer of impulse force to the legs during space launch. • Operational stability of offshore triceratops during rocket launch is verified. [ABSTRACT FROM AUTHOR]

This paper aims to present how to determine the critical section of a railway axle that is broken due to fatigue. It has been achieved by examining failures in the axle of the train wagons. For this purpose, a full wagon model with 19 degree-of-freedom (DOF) has been considered to obtain the dynamic forces acting on the wagon axle. By examining the dynamic forces and moments that affect the axle the critical section of the axle is determined to predict the region of the broken region. Furthermore, the variation of the safety factor related to wagon load and wagon speed is discussed by considering the passengers. [ABSTRACT FROM AUTHOR]

Simple dynamical systems are of interest always. In this paper, we propose a simple jerk system with one exponential nonlinearity. Dynamical properties of the proposed system are investigated. To show the practical realizability of the proposed system we implement the exponential jerk system using off the shelf components. Fractional order and time delays are considered as complex analysis patterns of nonlinear systems. We investigate the fractional order time delayed exponential jerk system. For numerical analysis we use the modified Adomian Decomposition Method. To show the engineering importance of the proposed system, we derive a pseudo random number generator based on it.Various test results are presented to show the randomness of the system. [ABSTRACT FROM AUTHOR]

• Numerical model of the fatigue experiments connected in an electrodynamic shaker base on the spectral element. • Analysis of a suitable boundary condition. • Analysis of the electrodynamic shaker-specimen interaction on the waves reflection point of view. • Model validation by comparing with a finite element model and experimental data. Generally, dynamic and fatigue tests require complicated and time-consuming simulation to achieve good performance. However, to estimate a structure's fatigue lifetime during a vibrational test, when the frequency response function is required, can be expensive or unsuitable. Thus, the coupling interaction between the electrodynamic shaker and the specimen is addressed, and an equivalent shaker spectral element model presented. In this context, the paper presents a study based on the spectral element approach to model the electrodynamic shaker. The spectral analysis is performed to predict the dynamic response of the specimen coupled with shaker by using the spectral element method. To validate the model it is compared with the experimental tests and numerical simulation obtained by using the Finite Element method. The dynamic response predictions using the presented model are similar to the experimental responses, showing the efficiency of this approach. [ABSTRACT FROM AUTHOR]

Highlights • The impact factors (IMs) of continuous beam bridges increase dramatically when resonance phenomena occur. Vehicle-bridge resonance is closely related not only to vehicle frequency and bridge frequency but also to the disturbance frequency caused by vehicle movement. Travelling velocity exerts an important influence on resonance. In most cases, the IM of a continuous beam bridge reaches its peak at a low travelling velocity. • Vehicle-bridge resonance may be caused by the first-order mode or the second-order mode of a bridge. Second-order curvature modes exert an especially crucial influence on the IMs of the negative moment at the interior supports. The maximum IM of continuous beam bridges at the interior supports is much larger than the maximum IM at the mid-spans, which is an important feature of the IMs of continuous beam bridges. • For the VM at the interior supports, the maximum DAF may be more than 1.7. If the design vehicular load specified in AASHTO code is used, the DLA of 33% is applicable to the force effect at the supports. However, when the same static traffic load standard is applied to both interior supports and mid-spans, a DLA of 75%, which is used for the deck joint in AASHTO code (2017), is necessary for the moment effect at interior supports. Abstract The impact factors of multi-span continuous box girder bridges in highways are influenced by many factors, including road roughness, vehicle-bridge interactions (VBIs), and travelling velocity. Currently, the empirical formulas specified by bridge design codes are based on single factors (bridge length or fundamental frequency). These formulas yield inconsistent results that can differ widely. In this paper, the regularity of the dynamic amplification factors (DAFs) of continuous beam bridges is investigated by selecting 15 continuous beam bridges and conducting VBI analyses. The results indicate that the DAFs of the continuous beam bridges increase dramatically when resonance phenomena occur. The vehicle-bridge resonance is closely related to vehicle frequency, bridge frequency and the disturbance frequency caused by vehicle movement. The travelling velocity exerts an important influence on the resonance. In most cases, the DAF of a continuous beam bridge peaks at the velocity range of 40–60 km/h. Vehicle-bridge resonance may be caused by the first-order or second-order mode of a bridge. Second-order curvature modes exert an especially crucial influence on the DAF of the negative moment at the interior supports. The empirical formulas used in current bridge design codes fail to account for the influence of resonance and travelling velocity on the DAFs of bridges. The maximum DAF at the interior supports of the continuous beam bridges may exceed 1.7. [ABSTRACT FROM AUTHOR]

This paper summarises the experience gained from wave basin experiments aimed at investigating the dynamic response of a spar buoy offshore wind turbine, under different wind and wave conditions. The tests were performed at the Danish Hydraulic Institute within the framework of the EU-Hydralab IV Integrated Infrastructure Initiative. The Froude-scaled model was subjected to regular and irregular waves, and to steady wind loads. Measurements were taken of hydrodynamics, displacements of the floating structure, wave induced forces at critical sections of the structure and at the mooring lines. First, free vibration tests were performed to obtain natural periods and damping ratios. Then, displacements, rotations, accelerations, and forces were measured under regular and irregular waves and three different wind conditions corresponding to cut-in, rated speed and cut-out. RAO, Statistical and spectral analyses were carried out to investigate the dynamic behaviour of the spar buoy wind turbine. The results show that most of the dynamic response occurs at the wave frequency, with minor contributions at the first and second harmonics of this, and at the natural rigid-body frequencies. In addition, in many cases a non-negligible contribution was found at the first bending frequency of the structure; this suggests that Cauchy scaling of the model cannot be neglected. According to the EU-Hydralab IV programme ‘Rules and conditions’ ( www.hydralab.eu ), the raw data are public domain, and therefore they represent a unique dataset of measurements, possibly useful for further analyses, for calibration and validation of numerical models, and for comparison with full scale observations. [ABSTRACT FROM AUTHOR]

We present the results of nonlinear dynamic analyses performed on reinforced concrete (RC) moment resisting frames (MRFs). The analyses were performed considering SSI by means of both a plane-strain soil-structure finite element model approach and a structure-on-springs approach. The results show that the complete FE model approach may produce significant differences in the evaluation of the seismic demand, in terms of maximum inter-storey drift, with respect to the fixed-base structure and to the structure-on-springs approach, mainly because of the different incorporation of the damping in the two modeling approaches. Differences in the soil properties, the seismic design level of the structures and the modeling technique of SSI effects are reflected as reduction in the seismic demand with respect to a fixed-base model, up to 50% in maximum inter-story drift ratio and up to 20% in maximum base shear for the complete FE model and up to 20% in both maximum base shear and maximum inter-story drift ratio for the simplified BNWF model. [ABSTRACT FROM AUTHOR]

Internet of Things (IoT) devices are extensively used in modern industries combined with the conventional industrial control system (ICS) network through the industrial cloud to make the production data easily available to the corporate business management and easier control for highly profitable production systems. The different devices within the conventional ICS network originally manufactured to run on an isolated network and was not considered for the privacy and security of the control and production/architecture data being trafficked over the manufacturing plant to the corporate. Due to their extensive integration with the industrial cloud network over the internet, these ICS networks are exposed to a significant threat of malicious activities created by malicious software. Protecting ICS from such attacks requires continuous update of their database of anti-malware tools which requires efforts from manual experts on a regular basis. This limits real time protection of ICS. Earlier work by Huda et al. (2017) based on a semi-supervised approach performed well. However training process of the semi-supervised-approach (Huda et al., 2017) is complex procedure which requires a hybridization of feature selection, unsupervised clustering and supervised training techniques. Therefore, it could be time consuming for ICS network for real time protection. In this paper, we propose an adaptive threat detection model for industrial cloud of things (CoT) based on deep learning. Deep learning has been used in many domain of pattern recognition and a popular approach for its simple training procedure. Most importantly, deep learning can learn the hidden patterns of the domain in an unsupervised manner which can avoid the requirements of huge expensive labeled data. We used this particular characteristic of deep learning to design our detection model. Two different types of deep learning based detection models are proposed in this work. The first model uses a disjoint training and testing data for a deep belief network (DBN) and corresponding artificial neural network (ANN). In the second proposed detection model, DBN is trained using new unlabeled data to provide DBN with additional knowledge about the changes in the malicious attack patterns. Novelty of the proposed detection models is that the models are adaptive where training procedures is simpler than earlier work (Huda et al, 2017) and can adapt new malware behaviors from already available and cheap unlabeled data at the same time. This will avoid expensive manual labeling of new attacks and corresponding time complexity making it feasible for ICS networks. Performances of standard DBNs are sensitive to its configurations and values for the hyper-parameters including number of hidden nodes, learning rate and number epochs. Therefore proposed detection models find an optimal configuration by varying the structure of DBNs and other parameters. The proposed detection models are extensively tested on a real malware test bed. Experimental results show that the proposed approaches achieve higher accuracies than standard detection algorithms and obtain similar performances with earlier semi-supervised work (Huda et al., 2017) but provide a comparatively simplified training model. [ABSTRACT FROM AUTHOR]

In this study, sine-shaped micro-grooved surfaces with depth of 12–24 μm and width of 30–60 μm were precisely and smoothly fabricated using dry etching technique on aluminium surfaces. After hydrophobic modification, the wettability and the heat transfer characteristics of dropwise condensation on the micro-grooved surfaces were investigated experimentally, and the coalescence and sweeping processes of droplets on micro-grooved surfaces were dynamically analyzed. As the results show, the wetting behavior and heat transfer characteristics on the micro-grooved surfaces presented anisotropic characteristics, the static contact angle in perpendicular direction θ ⊥ was significantly larger than that in parallel direction θ ∥ , and same trends can also be observed for contact angle hysteresis. In heat transfer experiments, the plates were set vertically and the grooves were arranged in two positions, vertical and horizontal. For the vertically grooved surface, the sweeping effects of falling droplets were enhanced by the vertical grooves and the heat transfer during dropwise condensation was increased to 30–50%. Better heat transfer performance can be achieved when the ratio of height to pitch, A/P, increased. Different from vertical grooved surfaces, the experimental results obtained from horizontal grooved surfaces were similar to the results of smooth surface. Both net force and sliding velocity increased as droplets grew, and larger geometrical size was favorable to droplets falling for same ratio of A/P. The velocities of sliding down on horizontal grooved surface were only 60–70% of that on smooth surface, while the velocities of sliding down on vertical grooved surfaces can reach 1.2 times or higher than that on smooth surface. [ABSTRACT FROM AUTHOR]

The paper investigates the influence of Soil-Structure-Interaction (SSI) effects on the seismic performances of 2D reinforced concrete (RC) moment resisting frames (MRFs), which were investigated by means of non-linear dynamic analyses. The goal was pursued by means of a parametric study in which (1) the soil properties, (2) the modelling technique of the SSI effects, (3) the seismic design level of the structures were varied. The soil classes suggested by Eurocode 8 were taken as reference to define the mechanical properties of soil. As concerns the SSI modelling, both a sub-structures approach and a direct approach were considered. Finally, structures of 4 and 8 floors designed for vertical loads only or according to the Italian regulations for constructions (NTC-08) were considered. RC-MRFs founded on soft soils were considered, because SSI effects on the seismic response are expected higher. The study shows that SSI affects the seismic demand in terms of maximum base shear and maximum inter-story drift ratio with different significance depending on the modelling approach. [ABSTRACT FROM AUTHOR]

Approaches for modeling the complex mechanical systems of mobile machines are discussed. Basic definitions related to schematization and dynamic analyses of mechanical systems are justified. Typical mistakes in schematization and building the mathematical models are analyzed. The technique for modeling the mechanical variable-structure systems is proposed.

Game-based environments frequently afford students the opportunity to exert agency over their learning paths by making various choices within the environment. The combination of log data from these systems and dynamic methodologies may serve as a stealth means to assess how students behave (i.e., deterministic or random) within these learning environments. The current work captures variations in students' behavior patterns by employing two dynamic analyses to classify students' sequences of choices within an adaptive learning environment. Random Walk analyses and Hurst exponents were used to classify students' interaction patterns as random or deterministic. Forty high school students interacted with the game-based system, iSTART-ME, for 11-sessions (pretest, 8 training sessions, posttest, and a delayed retention test). Analyses revealed that students who interacted in a more deterministic manner also generated higher quality self-explanations during training sessions. The results point toward the potential for dynamic analyses such as random walk analyses and Hurst exponents to provide stealth assessments of students' learning behaviors while engaged within a game-based environment. [ABSTRACT FROM AUTHOR]

We analyze how the bubble trends of different asset prices are dynamically transmitted between one another under a co-integrated VAR model. The vector bubble trends are defined by a random walk trend derived from Beveridge-Nelson decomposition allowing a co-integration between multiple asset prices and their fundamentals. This I(1) bubble trend is connected to the no-arbitrage condition for efficient asset pricing and is composed of Accumulated Cointegration Error (ACE). Under this setup, we may conduct dynamic analyses of the vector ACE bubble trends, which enables us to assess the interrelationships of bubbles of different assets and the dynamic role of bubbles in asset pricing. It may be critical for a preemptive policy reaction to block any possible contagion of an asset price bubble that might be harmful to the economy. Using the monthly data of the U.S. and impulse response analyses, we empirically find that (i) there are ACE bubble trends in both stock and housing prices; (ii) the stock and housing price bubbles are highly correlated with one another; (iii) stock prices are more bubble-dependent than housing prices; and (iv) the stock bubble affects the housing bubble, but the reverse case does not hold. [ABSTRACT FROM AUTHOR]

In the areas of seismic engineering, shaking table tests are powerful methods for assessing the seismic capacity of buildings. Since the size and capacity of existing shaking tables are limited, using scale structural models seems to be necessary. In recent years, many experimental studies have been performed using shaking table tests to determine seismic response of structural models subjected to various earthquake records. However, none of the past research works discussed practical procedure for creating the physical model. Therefore, in this study, a comprehensive procedure for design, building and commissioning of scale tall building structural models has been developed and presented for practical applications in shaking table test programmes. To validate the structural model, shaking table tests and numerical time history dynamic analyses were performed under the influence of different scaled earthquake acceleration records. Comparing the numerical predictions and experimental values of maximum lateral displacements, it became apparent that the numerical predictions and laboratory measurements are in a good agreement. As a result, the scale structural model can replicate the behaviour of real tall buildings with acceptable accuracy. It is concluded that the physical model is a valid and qualified model that can be employed for experimental shaking table tests. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Computer simulations are currently often utilized tools in vehicle design, diagnostics of vehicle behaviour and evaluation of their characteristics. The vehicle multibody system (MBS) represents a complicated mechanical system especially when flexible bodies are considered, modelled and implemented in the calculation. Multibody system dynamics is based on classical mechanics and its engineering applications range from mechanisms, through means of transport, to biomechanics. Results of multibody system dynamics are most important for an assessment and diagnostics of transport means behaviour even in the development phase. This paper deals with the multibody system dynamic approach and its application in vehicle multibody systems. The first part of this paper focuses on a general approach to the multibody system of vehicles, especially of rail vehicles, and it includes fundamentals of multibody system dynamics. The next part deals with practical use of multibody system software. A multibody system of a passenger car have been modelled using commercial software, we have carried out simulations of a passenger car running on the real track, and subsequently we assessed its ride properties and evaluated its passenger comfort level. [ABSTRACT FROM AUTHOR]