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The development of the economy and technology has attracted greater attention to regional seismic resistance, a key technology for which is the simulation of regional seismic ground motions. This study proposes a simple and highly operable method for the generation of regional seismic ground motions, which includes five steps. First, a seismic ground motion recorded at a seismic station is selected as the original ground motion. The original ground motion is then decomposed into eight sub-signals by wavelet packet transform (WPT). Next, the eight sub-signals are adjusted by the frequency attenuation model. The generated ground motion is then amplitude modulated by the peak ground acceleration (PGA) attenuation model. The frequency attenuation model and the PGA attenuation model are obtained by fitting seismic data from the 1999 Chi-Chi earthquake. Finally, the propagation of the ground motion is considered. The proposed method can provide a time history of seismic ground motions for any point in a region. To investigate the rationality and applicability of the proposed method, the characteristics of the generated seismic ground motions are compared with those of true seismic ground motions. The average error of the PGA of the generated ground motions and the true ground motions is 0.072$g$; thus, the proposed method is suitable for use in small-scale regions. Furthermore, 4-story and 15-story structures are used for structural response analysis. The story drift ratio error between the generated ground and true ground motions is found to be within an acceptable error range. The proposed method provides a new way to generate ground motions for regional seismic investigation.

The aim of this work is to implement a statistical mechanics theory of social interaction, generalizing econometric discrete choice models. A class of simple mean-field discrete models is introduced and discussed both from the theoretical and phenomenological point of view. We propose a parameter evaluation procedure and test it by fitting the model against three families of data coming from different cases: the estimated interaction parameters are found to have similar positive values, giving a quantitative confirmation of the peer imitation behavior found in social psychology. Furthermore, all the values of the interaction parameters belong to the phase transition regime suggesting its possible role in the study of social systems.

This research explores the ability of 60mm thick reinforced concrete (RC) plates to resist impacts from ogive-nosed hard steel projectiles. The projectiles used in the present study have a diameter of 19mm, a length of 200mm, and a mass of 0.4kg impacted on the RC plates with incident velocities ranging from 92m/s to 161m/s. Numerical simulations were conducted using ABAQUS/Explicit finite element software to validate the experimental results. The Holmquist–Johnson–Cook (HJC) material model was employed to simulate the constitutive behavior of concrete, while the Johnson–Cook (JC) material model was used to simulate the material response of reinforcing steel bars. The residual velocities obtained from the simulations closely matched the actual experimental results, showing a polynomial correlation with the incidence velocities of the projectiles. Moreover, the experimentally and numerically determined ballistic limit for the 60mm thick RC plate was found to be 108m/s and 109.5m/s, respectively. In contrast, the ballistic limit calculated using empirical mathematical expressions was 107.4m/s. This alignment between predicted, calculated, and actual ballistic limits underscores the reliability and accuracy of both numerical and empirical approaches.

The aim of this study is to establish a biomechanical model of bone on the basis of cellular structure and then to evaluate its accuracy for the clinical application. The thighbone of swine was scanned by computed tomography (CT). The resulting sectional images were input into MIMICS10.01 to generate a three-dimensional geometric model. A biomechanical model of bone was built on the basis of cellular structure, and calculations of the model were implemented in MATLAB with the finite element method. With this cellular mechanics model, axial compression load was simulated, and load–axial and load–transverse strain at the measurement points were detected. To evaluate the model, a mechanics model derived from an empirical formula was simulated under the same conditions, and an actual biomechanical experiment was also conducted. The simulated results obtained from the two models were then compared with the test results, indicating that the simulated results for the cellular model were closer to the test results than those for the empirical mechanics model. Therefore, the proposed cellular mechanics model shows advantages in accuracy and scope of application for bone modeling.

This work addresses the shelf life characteristics of P3HT: PCBM blend based organic solar cells (OSC) fabricated with Ca–Al and LiF–Al cathodes. Some of these devices are encapsulated in nitrogen ambient and some in room ambient. Device electrical characteristics are studied under both dark and light. In the analysis under dark ambient conditions, the degradation in peak dark current is monitored over time (in days) and an empirical model is postulated for the degradation based on statistical curve fitting techniques. In the analysis under light, degradation of parameters such as fill factor (FF), open circuit voltage (V_oc) and short circuit current density (J_sc) is monitored over time in these devices (for different cathodes and different ambients) and the results are analyzed and compared. Also, accelerated stress tests are conducted wherein the devices are subjected to continuous illumination for a period of 1.5 h under two different intensities (0.76 sun and 1 sun) and again, the results are analyzed and compared. A model is fitted to the observed degradation in normalized J_sc and the degradation constants (k_deg) are obtained. It is seen that the devices fabricated with cathode as LiF–Al and being encapsulated in nitrogen ambient provide the best performance over time.

Energy consumption and its associated consequences can be reduced by implementing district cooling strategies that supply low temperature water to a wide range of end users through chillers and distribution networks. Adequate understanding, performance prediction and further optimization of vapor compression chillers used widely in district cooling plants have been a subject of intense research through model-based approaches. In this context, we perform an extensive review of different modeling techniques used for predicting steady-state or dynamic performance of vapor compression liquid chillers. The explored modeling techniques include physical and empirical models. Different physical models used for vapor compression chillers, based on physics laws, are discussed in detail. Furthermore, empirical models (based on artificial neural networks, regression analysis) are elaborated along with their advantages and drawbacks. The physical models can depict both steady- and unsteady-state performance of the vapor compression chiller; however, their accuracy and physical realism can be enhanced by considering the geometrical arrangement of the condenser and evaporator and validating them for various ecofriendly refrigerants and large system size (i.e., cooling capacity). Apparently, empirical models are easy to develop but do not provide the necessary physical realism of the process of vapor compression chiller. It is further observed that DC plants/networks have been modeled from the point of view of optimization or integration but no efforts have been made to model the chillers with multiple VCR cycles. The development of such models will facilitate to optimize the DC plant and provide improved control strategies for effective and efficient operation.

Nowadays, many banks in Europe, as well as many financial institutions in general, have realised the need to change their business activities, and must pay attention to “how to invest”. A new approach to investing money is green investments. Green investments are part of the green economy that contributes to the sustainable development concept. This study provides a detailed description of the terms of green investments, green finance and green bonds. This is used to compare countries at different levels of sustainable development. Malaysia is a country that is much more on the road to economic sustainability, and it will be compared to Serbia, North Macedonia, and Bosnia and Herzegovina, as countries that are in the process of transition. We aim to present the best practices of green investment in developed countries and provide suggestions for these practices to be adopted and the actions required to implement them in less developed economies.