Dynamic Analysis Model Research Articles

Determinants of Import in ASEAN Economic Community

Introduction: Imports are an important component of economic development in developing countries, including in the ASEAN Economic Community. Purpose: The aims of this study to analyze the determinants of import in ASEAN Economic Community. Methodology/Approach: The research method used is panel data analysis from 2010-2019. The research variables include imports as the dependent variable and export variables, exchange rates, population, inflation, GDP and interest rates as independent variables. This study is to analyze the determinants of imports in the economies of ASEAN community countries starting from the results of the Chow test and Hausmen test which compare the static and dynamic fixed effect panel data analysis models. Findings: The results of this study indicate that imports for ASEAN economic community are influenced by the variables of exports, FDI and population. The results of this study also show that imports for ASEAN economic community are a necessity to support their economic development. Originality/Value/Implication: The conclusion and recommendation from this research is that imports are an important component in economic development in ASEAN economic community, so it is necessary to have an integrated policy among ASEAN economic community to build economic cooperation to reduce economic dependence from outside. ASEAN economic community need to improve economic efficiency and international competitiveness to encourage exports of flagship products in international markets.

Determinants of Import in ASEAN Economic Community

Introduction: Imports are an important component of economic development in developing countries, including in the ASEAN Economic Community. Purpose: The aims of this study to analyze the determinants of import in ASEAN Economic Community. Methodology/Approach: The research method used is panel data analysis from 2010-2019. The research variables include imports as the dependent variable and export variables, exchange rates, population, inflation, GDP and interest rates as independent variables. This study is to analyze the determinants of imports in the economies of ASEAN community countries starting from the results of the Chow test and Hausmen test which compare the static and dynamic fixed effect panel data analysis models. Findings: The results of this study indicate that imports for ASEAN economic community are influenced by the variables of exports, FDI and population. The results of this study also show that imports for ASEAN economic community are a necessity to support their economic development. Originality/Value/Implication: The conclusion and recommendation from this research is that imports are an important component in economic development in ASEAN economic community, so it is necessary to have an integrated policy among ASEAN economic community to build economic cooperation to reduce economic dependence from outside. ASEAN economic community need to improve economic efficiency and international competitiveness to encourage exports of flagship products in international markets.

Dynamic analysis and energy consumption modeling of a composite spindle with active magnetic bearings for a sustainable manufacturing

Modern life is marked with the extensive use of machine tools. The latter stand for high consumers of electrical energy which increase carbon emissions. For this reason, various solutions aiming to reduce energy consumption in industrial sector are elaborated. One solution lies in the use of economical materials for the spindle rotation system supported by active magnetic bearings (AMBs), which corresponds to a problem that has never been undertaken so far. A new conception for machine tool spindle rotation system is elaborated for sustainable design. The spindle material is composed of a carbon epoxy hollow shaft wrapped with a steel layer and supported by AMBs. A Finite Element Method (FEM) modeling of the spindle rotation system was carried out to assess its dynamic consumed energy and power during the acceleration and cutting phases. For an accurate estimation, the power consumed by the spindle system was calculated taking into account the dynamic behavior of the cutting force and losses generated by the bearings. A comparison between energies consumed by the proposed spindle system and the steel spindle system was enacted.

Physics-informed data assimilation model for displacement prediction of hydrodynamic pressure-driven landslide

Due to the complex and non-linear characteristics of landslide evolution, the deformation law of landslides is always hard to be predicted. Considering the dynamical evolution process of landslide physical mechanism, a Physics-Informed Data Assimilation (PIDA) method is first proposed for landslide displacement forecasting. It can enhance the prediction ability of the physical forecasting model, and solves the problem of ignoring the physical significance of landslides in mathematical prediction model. Additionally, the superiority of Particle Filter (PF) in nonlinear and non-Gaussian system determines its application in complex problem. Aiming at the hydrodynamic pressure-driven landslide, the Sliding Zone Deterioration (SZD) model is constructed as the state equation of the PF algorithm. And the observation equation is formed by the relationship between landslide deformation and monitoring datasets. The physics-informed landslide displacement prediction model serves as a bridge, consisting of the shear strength parameter dynamic updated model and physical mechanism analysis model, for key parameters feedback, modification, and update. Comparing the results to traditional Long Short-Term Memory (LSTM) and Back Propagation Neural Network (BPNN) methods, the PIDA method combining triggering and instability mechanisms performs better in accuracy. Moreover, it enables dynamic and reliable landslide deformation prediction.

Analysis on the Dynamic Behavior of Space Shafting under Combined Load

The space shafting is the core component of the momentum exchange attitude control actuator for spacecraft.The dynamic behavior of space shafting has an important impact on the performance of the actuators. Based on the dynamic theory of rolling bearing, this paper presents a dynamic analysis model of space shafting for the interaction between bearing balls and oil-containing nonmetallic cage under combined loads. Also, the accuracy of the analysis model was verified through a high-speed camera system to conduct a cage speed test. In addition, the dynamic behavior of balls and cage under combined loads and the interaction between them is also analysed. The results show that the axial displacements of balls fluctuate periodically under combined loads, and the rotation speeds of balls and cage are easily affected by the load, presenting as the oscillation of speed. Also, the force between balls and cage increases as the load increases. The dynamic behavior of balls and cage could be effectively improved by avoiding excessive torque loads and limiting the axial preload to 40 N. The wear failure caused by unstable operation of bearings cannot be ignored. This model is more practical in completing simulation analysis of different operating conditions and structural parameters of the shafting system. It provides a theoretical reference for the structural design and performance analysis of space shafting.

A Numerical Model for Stability and Dynamic Analyses of a Floating Dock During Operations

A Numerical Model for Stability and Dynamic Analyses of a Floating Dock During Operations

Avaliação sísmica em um pórtico de concreto armado considerando a modelagem com plasticidade concentrada e distribuída

Abstract Researchers must decide on how they will model the non-linear material response in a Finite Element simulation to assess seismic vulnerability. This paper aims at giving an insight into these modelling decisions by comparing Fiber and Lumped Plasticity Finite Element Models in static and dynamic non-linear analysis in a RC frame. The methodology is based on the performance-based earthquake engineering to determine the expected damage on structures. The results indicate that both models are in good agreement with the static analysis, and when considering Extensive and Complete Damage Limit States on the dynamic analysis. The choice between them depends on the main goals of the research and resources available, since they have a significant difference in processing time.

Recovery pathway assessment of recycled HDPE for circular economy: Shorter-life vs longer-life products

High Density Polyethylene (HDPE) is a highly recyclable thermoplastic comprising 17% of all plastic produced. Yet, demand for recycled HDPE (r-HDPE) has outrun availability, partly due to manufacturers’ interest in meeting sustainability goals and recycled content mandates. Given that HDPE has a variety of uses, understanding optimal allocation of the constrained r-HDPE supply across product categories and lifespans will support the challenge of addressing broader sustainability goals and establishing circular economy (CE). By utilizing systems dynamic (SD) and life cycle analysis (LCA) modeling, this work studies whether prioritizing r-HDPE for longer-life products is more environmentally beneficial, compared to shorter-life products (e.g., food-grade packaging). Specifically, this work compares the production of milk containers and drainage pipes using virgin and r-HDPE as examples of HDPE applications through three scenarios. Key findings emerged from this study including the demonstration of a slight advantage to prioritizing allocating the constrained r-HDPE supply to the longer-life product vs the shorter-life product and a distinct challenge in hitting recycled content targets with current recycling rates and 2030 goals for the United States. This highlights a need to expand current recycling infrastructure in tandem with other CE practices to reduce plastic consumption and sustain environmental health for all.

Temporal Dynamic Synchronous Functional Brain Network for Schizophrenia Classification and Lateralization Analysis.

Available evidence suggests that dynamic functional connectivity can capture time-varying abnormalities in brain activity in resting-state cerebral functional magnetic resonance imaging (rs-fMRI) data and has a natural advantage in uncovering mechanisms of abnormal brain activity in schizophrenia (SZ) patients. Hence, an advanced dynamic brain network analysis model called the temporal brain category graph convolutional network (Temporal-BCGCN) was employed. Firstly, a unique dynamic brain network analysis module, DSF-BrainNet, was designed to construct dynamic synchronization features. Subsequently, a revolutionary graph convolution method, TemporalConv, was proposed based on the synchronous temporal properties of features. Finally, the first modular test tool for abnormal hemispherical lateralization in deep learning based on rs-fMRI data, named CategoryPool, was proposed. This study was validated on COBRE and UCLA datasets and achieved 83.62% and 89.71% average accuracies, respectively, outperforming the baseline model and other state-of-the-art methods. The ablation results also demonstrate the advantages of TemporalConv over the traditional edge feature graph convolution approach and the improvement of CategoryPool over the classical graph pooling approach. Interestingly, this study showed that the lower-order perceptual system and higher-order network regions in the left hemisphere are more severely dysfunctional than in the right hemisphere in SZ, reaffirmings the importance of the left medial superior frontal gyrus in SZ. Our code was available at: https://github.com/swfen/Temporal-BCGCN.

Water-energy-food nexus efficiency and its factor analysis in China: A dynamic series-loop DDF model

This paper presents an analysis of the water-energy-food nexus (WEFN) system, focusing on its interlinked structure and dynamic characteristics. This paper proposes a dynamic series-loop data envelopment analysis (DEA) model with a directional distance function for measuring WEFN efficiency in China. A spatial Durbin model is constructed to investigate the impact of extreme temperatures on WEFN efficiency. The results are as follows. (1) Compared with the black-box DEA model and series network DEA model, a series-loop network DEA model can reflect the “networking effect” and “looping effect” in the WEFN system. (2) The WEFN system performs well with an average series-loop efficiency of 0.875, but the efficiency of the water subsystem scores low and needs improvement. (3) At the national level, extremely high and low temperatures have no significant effect on the WEFN efficiency in local or adjacent provinces, whereas average temperature promotes the WEFN efficiency in local provinces but hinders it in neighboring provinces. In the regions with a low temperature difference, average temperature has no impact on the WEFN efficiency of both the province itself and its neighboring provinces. Overall, this study provides valuable insights into the complex interlinkages within the WEFN system and highlights the importance of considering these relationships when improving the system efficiency.

A hybrid model for dynamic analysis of domino effects in chemical process industries

A hybrid model for dynamic analysis of domino effects in chemical process industries

Damping models for dynamic analysis of masonry vaults with discrete elements

Damping models for dynamic analysis of masonry vaults with discrete elements

Studying Foreign Trade and Economic Growth of Morocco using Regression and Grey Relational Analyses

The study conducts an empirical examination of the relationship between foreign trade and economic growth in Morocco, employing two distinct analytical models: The Dynamic Grey Relational Analysis (GRA) model and the Multiple Regression model. The empirical outcomes reveal that foreign trade exerts a statistically significant and positive influence on the economic growth of Morocco, a relationship consistently substantiated by both the GRA and regression models. Nevertheless, it is important to emphasize that the linkage between these variables is characterized by a high degree of dynamism, influenced by a diverse array of economic determinants. Furthermore, the results point to the primary pathway through which foreign trade impacts economic growth in Morocco, highlighting its role in fostering capital accumulation and technological progress. Consequently, this study implies that strategic policies oriented toward the promotion of foreign trade and foreign investment have the potential to significantly bolster sustained economic growth within the Moroccan context.

Multi-objective metaheuristic optimization for simplified modeling of soil-pile interaction systems under lateral and rocking motions

A consistent lumped-parameter model (LPM) is established to characterize the dynamic response of single and group piles in a homogeneous half-space subjected to coupled lateral-rocking vibrations. The proposed model comprises adjustable modules that can adapt to simulate a wide range of pile foundation configurations. This study utilizes a metaheuristic algorithm to solve a bicriteria optimization problem, aiming to determine both the layout and parameters of the optimal LPM. The optimal model is created to approximately reproduce the amplitude and phase angle of a soil-pile interaction (SPI) system undergoing harmonic loadings. Besides, the proposed model using frequency-independent elements allows for rapid computation of dynamic responses in the SPI system. Several analyses in the time and frequency domains validate the performance of the proposed model undergoing forced vibrations and seismic excitations. The analyzed results prove the capability and accuracy of the proposed model in approximating the dynamic responses of SPI systems. The results presented demonstrate the significant potential of the proposed model for dynamic structural analysis, particularly when accounting for structural nonlinearities in the time domain.

DL-AMDet: Deep learning-based malware detector for android

The Android operating system, with its market share leadership and open-source nature in smartphones, has become the primary target of malware. However, detecting malicious Android processes has become a significant challenge because of the complexity of size, length, and associations of various important and distinctive elements of Android applications, such as API calls and system calls. In this paper DL-AMDet, a deep learning architecture is proposed to detect Android malware applications based on its static and dynamic features. DL-AMDet consists of two main detection models the first one uses CNN-BiLSTM deep learning method for detecting malware using static analysis. The other model utilizes deep Autoencoders as an anomaly detection model to identify the malware based on dynamic analysis. The performance of the DL-AMDet architecture is evaluated using two different datasets. The results show that DL-AMDet achieves a competitive malware detection accuracy of 99.935 % for static and dynamic analysis models combined. Additionally, the results emphasize the significance of CNN-BiLSTM and Deep Autoencoders models used in DL-AMDet to outperform the existing state-of-the-art techniques.

A dynamic three-way conflict analysis model with adaptive thresholds

Three-way conflict analysis model, based on information systems, is about trisecting, getting coalitions and decision-making. Since the model is proposed by Yao, many models have been proposed to enrich the field of three-way conflict analysis. In this paper, we propose a new three-way conflict analysis model. Our work can be divided into four parts. First, we define new fuzzy granules and an new approximation operator to obtain better trisections. Second, we introduce dynamic information systems which are generalizations of classical information systems. The new information systems enable us to induce trisections dynamically. Third, a new Bayesian algorithm is proposed for thresholds-computing which plays an important role in inducing trisections. In the classical Bayesian approach, there are six original parameters given subjectively. And in our algorithm, the parameters are replaced by three centers and a distance measure. Finally, our new model is applied to tourism planning in two cases, one can be presented by a dynamic information system and the other one can be presented by a dispersed information system generalized from dynamic information system.

Research on the Relationship between Dynamic Characteristics and Friction Torque Fluctuation of CMGB under the Condition of Time-Varying Moment

In this paper, a dynamic simulation analysis model was established for CMGB (control moment gyroscope bearing) under the conditions of time-varying moment. The influences of the moment’s response time, axial preload, and working temperature on the dynamic characteristics and friction torque of CMGB were analyzed, and the relevant verification tests were conducted. The results show that the friction torque fluctuation of CMGB directly corresponds to the dynamic characteristics. The faster the response time of the time-varying moment, the larger the friction torque fluctuation of CMGB. The larger preload minimizes the difference in the ball’s loading state, which is the actual reason for reducing the friction torque fluctuation. Moreover, as the working temperature increases, the friction torque fluctuation of CMGB decreases.

Prediction of nonlinear vibration characteristics for high-speed and ultra-precision mechanism with clearance joints

The main purpose of this study is to present a comprehensive approach to illustrate the dynamic behavior of ultra-precision mechanism with clearance joints. According to geometrical features, the Largrange's equations of this mechanism is established. In order to describe the contact-impact process accurately, the models of dissipative contact force and modified friction force are introduced into the dynamic analysis model of this mechanism with clearance joints, which could describe the vibration characteristics clearly. Moreover, the experimental performance platform of high-speed and ultra-precision mechanism is designed and built. Then, the dynamic response of this mechanism is represented with the simulation and experiment, which demonstrates the effectiveness of proposed model. In addition, the probability statistics, largest Lyapunov exponent and bifurcation characteristics are employed to study the effects of clearance joints on the dynamic behavior of this mechanism.

A semi-analytical multi-harmonic balance method on full-3D contact model for dynamic analysis of dry friction systems

Dry friction damping structures are widely-used in aero-engines to mitigate vibration. The nonlinear nature of friction and the two-dimensional in-plane motion on the contact interface bring challenges to accurately and efficiently predict the forced response of frictionally damped structures. The state-of-the-art Multi-Harmonic Balance Method (MHBM) on quasi-3D contact model in engineering cannot precisely capture the kinematics on the friction interface although the efficiency is high. The full-3D contact model can describe the constitutive relationship of the interface in a more accurate manner; however, the efficiency and convergence are not guaranteed for large-scale models. In this paper, a semi-analytical MHBM on full-3D contact model is proposed. The original Trajectory Tracking Method (TTM) for evaluating the contact force is reformulated to make the calculation more concise and the derivation of the Analytical Jacobian Matrix (AJM) feasible. Based on the chain rule of derivation, the AJM which is the core to upgrade the performance is deduced. Through a shrouded blade finite element model, the accuracy and efficiency of the proposed method are compared with both the MHBM on full-3D contact model with numerical Jacobian matrix and the MHBM on quasi-3D contact model with AJM. The results show that the AJM improves significantly the efficiency of the MHBM on full-3D contact model. The time cost of the proposed method is in the same order of magnitude as that of the MHBM on quasi-3D contact model. We also confirm that the full-3D contact model is necessary for the dynamic analyses of shrouded blades. If one uses the quasi-3D model, the estimation relative error of damping can even reach 31.8% in some cases. In addition, the AJM also brings benefits for stability analysis. It is highly recommended that engineers use the MHBM on full-3D contact model for the dynamic analysis and design of shrouded blades.

Nonlinear dynamic analysis of a geometrically imperfect sandwich beam with functionally graded material facets and auxetic honeycomb core in thermal environment

In this study, a model for the nonlinear dynamic analysis of the geometrically imperfect sandwich beam with functionally graded material (FGM) facets and auxetic honeycomb core is proposed. The auxetic feature of the honeycomb material is realized by a homogenization method, which gives the expressions of the effective material coefficients in terms of material property and cellular geometric parameters. The nonlinear motion equation of the geometrically imperfect beam is derived based on the Reddy's higher shear deformation theory, von Kármán nonlinear theory, as well as general geometric imperfection function. The thermal effect on the material properties and structural rigidity is also taken into account in this model. The Newmark method and Newton–Raphson iterative method are employed to solve the nonlinear motion equation of the sandwich beam. In numerical examples, the dynamic response of the sandwich beam under two types of load, i.e. moving load and impulse load, are discussed in details. The influences of various factors (such as material parameter, geometric imperfection, and thermal condition) on the nonlinear dynamic behaviors of the sandwich beam are elaborately investigated. The numerical results show those factors can play significant roles in the bearing ability, structural stiffness, or nonlinear dynamic behaviors of the sandwich beam in certain conditions. Some key conclusions on the influences are drawn from the numerical results, which can be a useful reference for future investigations.