Model System For Interactions Research Articles

Shaking table test on seismic responses of asymmetrical underground subway stations

Currently, many subway stations are designed symmetrically and less attention has been paid to asymmetrical stations. The middle column of the asymmetric underground structure is offset to one side, which is not conducive to load bearing during strong earthquakes and is prone to damage. In this study, shaking table tests of a soil-symmetrical station and a soil-asymmetrical station were designed and conducted. A numerical model of the soil–structure interaction system was established, and the feasibility of the simulation method was verified. Then, the seismic responses of two kinds of stations were discussed and analysed. The results show that the dynamic response of both symmetrical and asymmetrical stations increases with the increase of the loading seismic intensity. Influenced by the size effect of the model test, there is less difference between the two models in their dynamic response. From the perspective of internal force and relative deformation, the response of the asymmetrical station is greater than that of the symmetrical station, which adequately reflects the disadvantage of asymmetrical structures in seismic design.

A Drosophila melanogaster model shows that fast growing Metarhizium species are the deadliest despite eliciting a strong immune response

ABSTRACT We used Drosophila melanogaster to investigate how differences between Metarhizium species in growth rate and mechanisms of pathogenesis influence the outcome of infection. We found that the most rapid germinators and growers in vitro and on fly cuticle were the fastest killers, suggesting that pre-penetration competence is key to Metarhizium success. Virulent strains also induced the largest immune response, which did not depend on profuse growth within hosts as virulent toxin-producing strains only proliferated post-mortem while slow-killing strains that were specialized to other insects grew profusely pre-mortem. Metarhizium strains have apparently evolved resistance to widely distributed defenses such as the defensin Toll product drosomycin, but they were inhibited by Bomanins only found in Drosophila spp. Disrupting a gene (Dif), that mediates Toll immunity has little impact on the lethality of most Metarhizium strains (an exception being the early diverged M. frigidum and another insect pathogen Beauveria bassiana). However, disrupting the sensor of fungal proteases (Persephone) allowed rapid proliferation of strains within hosts (with the exception of M. album), and flies succumbed rapidly. Persephone also mediates gender differences in immune responses that determine whether male or female flies die sooner. We conclude that some strain differences in growth within hosts depend on immune-mediated interactions but intrinsic differences in pathogenic mechanisms are more important. Thus, Drosophila varies greatly in tolerance to different Metarhizium strains, in part because some of them produce toxins. Our results further develop D. melanogaster as a tractable model system for understanding insect-Metarhizium interactions.

Peranan Sekuent Cartigram Pada Pemeriksaan MRI Knee Joint Dengan Kasus Anterior Cruciate Ligament DI Instalasi Radiologi RSUD Sidoarjo

Background: The MRI knee joint examination procedure for clinical ACL rupture in the Radiology Installation of Sidoarjo Regional Hospital often adds a T2 Mapping MR Cartigram sequence. T2 mapping MR Cartigram is a special sequence for detecting damage to the collagen component of the cartilage matrix using a quantitative approach method by producing a color map. The aim of this research is to determine the procedure, reasons for use, and diagnostic information resulting from the T2 mapping MR Cartigram sequence. Method: This type of research is qualitative research with a case study approach. The research was conducted in March-June 2022 at the Radiology Installation of Sidoarjo Regional Hospital. Research subjects included three patients, three radiographers, one radiologist, and one sending doctor. Data was collected by means of observation, interviews and documentation and then analyzed using an interactive model system method which would be processed in the form of transcripts, then identified, reduced and categorized the data and made open coding so that conclusions could be drawn. Results: The results of the study show that the clinical MRI knee joint examination procedure for ACL rupture at Sidoarjo District Hospital includes patient preparation, equipment preparation, examination techniques and routine sequences used such as PD Fatsat, T2, T1, STIR, T2*GRE, PD 3D Cube, and additional T2 Mapping MR Cartiram sequence. The use of the T2 mapping MR Cartigram sequence aims to determine the effect of ACL rupture on cartilage damage quantitatively and objectively by placing an ROI in the cartilage area so that it can provide diagnostic information including early detection of cartilage damage, increased water content, and cartilage degenerative processes. The results of the interpretation of the analysis carried out by the Sidoarjo Regional Hospital Radiologist were only subjective, namely looking at the resulting color map to see whether it looked even and homogeneous. Conclusion: Basically, existing saturation measurements are not always the same, they will depend on the patient's diagnosis for which the action will be taken. This saturation measurement uses the AVOXimeter 1000E. no less important in the continuity of actions in the cath lab room.

Proteasome activity is required for reovirus entry into cells.

Due to their limited genetic capacity, viruses are reliant on multiple host systems to replicate successfully. Mammalian orthoreovirus (reovirus) is commonly used as a model system for understanding host-virus interactions. In this study, we identify that the proteasome system, which is critical for cellular protein turnover, affects reovirus entry. Inhibition of the proteasome using a chemical inhibitor blocks reovirus uncoating. Blocking these events reduces subsequent replication of the virus. This work identifies that additional host factors control reovirus entry.

Bifurcation Analysis in a Tumor-Immune System Interaction Model with Dendritic Cell Therapy and Immune Response Delay

Bifurcation Analysis in a Tumor-Immune System Interaction Model with Dendritic Cell Therapy and Immune Response Delay

An improved local maximum synchrosqueezing transform with adaptive window width for instantaneous frequency identification of time-varying structures

Civil engineering structures usually exhibit time-varying characteristics under operational conditions due to changes in environment and loads. The identification of instantaneous frequencies (IFs) from measured responses of time-varying structures is a challenge when using the local maximum synchrosqueezing transform (LMSST) due to the difficulty in selecting the appropriate window width. In this study, an improved LMSST with adaptive window width (ALMSST) is proposed to circumvent the limitations of LMSST. The window width of ALMSST can be adaptively determined by combining the autoregressive power spectrum-based variational modal decomposition (AR-VMD) and a window width optimization algorithm. The AR-VMD is used to decompose the multi-component signal into mono-component signals. The Rényi entropy is adopted as an evaluation index in the window width optimization algorithm for selecting the optimal window width for each mono-component signal. Therefore, ALMSST can provide a highly concentrated time–frequency (TF) representation for all mono-component signals. Two simulated signals demonstrate that the ALMSST improves the accuracy of identified IFs compared with LMSST. Numerical simulation of a three-story shear building model with time-varying stiffness shows that ALMSST can accurately identify the IFs of time-varying structures under heavy noise. A cable test with linear and sinusoidal varying tension forces and a vehicle-bridge interaction (VBI) model system with different vehicle weights are investigated to verify the applicability of ALMSST to track the IFs of time-varying structures. Numerical simulation and experimental results illustrate that ALMSST performs well in identifying the IFs of time-varying structures.

Interactive System Modelling for the Internet of Things

The rapid growth in the number of Internet of Things (IoT) systems and their increasing use in safety-critical domains has led to the need for an evolution of development methods. Model-Driven Development (MDD) approaches have been used in software engineering to reduce development time and minimise errors in implemented systems. This paper introduces a novel Model-Driven Development (MDD) approach for Internet of Things (IoT) systems which considers interactivity from the perspective of both users and IoT components. A real-world example is presented to explain the motivation for the work and demonstrate the benefits and use of lightweight interactive system models adapted for the design and development of IoT systems.

Study on seismic vulnerability analysis of the interaction system between saturated soft soil and subway station structures

The seismic vulnerability of interaction system of saturated soft soil and subway station structures was explored in this paper. The coupled nonlinear numerical models of interaction system were established using the u–p formulation of Biot′s theory to describe the saturated two-phase media. A refined finite element model of interaction system was developed to study its nonlinear seismic responses and seismic hazard mechanism. In this study, the multi-yield elastoplastic constitutive model was adopted for the soil, while a fiber section elastoplastic constitutive model was used for the structure. The seismic response of the structure was calculated by inputting the artificial seismic wave obtained from the power spectrum-triangular series method. The maximum inter-story drift angle was taken as a structural performance parameter for the subway station structure. The structural demand cloud was obtained under random ground motion sequences. Based on the probabilistic seismic demand model analysis method, the seismic vulnerability curve of the subway station structure was plotted, and the seismic vulnerability curve was analyzed as per the vulnerability of performance parameters. With the increase of soil strength, the vulnerability index of subway station structure under different peak acceleration ground motion decreased correspondingly. Based on the above vulnerability theory and analysis methods, it can be found from the above vulnerability theory and analysis methods that the subway station structure with established buried depth in saturated soft soil site exhibits a certain degree of safety and reliability, and can meet the seismic fortification goal of "no damage in small earthquakes, repairable in medium earthquakes and no collapse in large earthquakes". The results of vulnerability analysis are in line with the actual seismic survey, and the vulnerability analysis method proposed in this paper can be applied to the vulnerability analysis of underground structures on saturated soft soil foundation.

Dynamic Response of Curved Tunnels under Vertical Incidence of Transversal SV Waves

Long tunnels often have curved sections when alignment designs are influenced by topography, adverse geology, and environmental factors. When the transversal SV wave is incident vertically, the curved section of the tunnel is subject to a connection between longitudinal and transversal loads, which are asymmetrical about the tunnel longitudinal axis. Compared to straight tunnels, curved tunnels are more complex in terms of forces and deformations and may become a key control section limiting the seismic safety of curved tunnels. To investigate the seismic response of curved tunnels, numerical simulations of curved tunnels with different radii of curvature under transversal SV seismic waves were carried out in this study. Local artificial boundaries were programmed and used for the 3D rock tunnel interaction system model to simulate semi-infinite rock and to eliminate fake reflections of seismic waves on local boundaries. The results show that longitudinal deformation and cross-sectional deformation occurred simultaneously in curved tunnels when the transversal SV wave was incident vertically. As the curvature increased, the longitudinal deformation of the curved tunnel increased. The cross-section of the tunnel was in oblique compression, and the cross-sectional internal force showed significant asymmetry. When the radius of curvature was 250 m, the difference in bending moment between the left and right haunch was 35.2%. These characteristics differ from those of straight tunnels and should be paid attention in the seismic design of curved tunnels.

Seismic performance and fragility of two-story and three-span underground structures using a random forest model and a new damage description method

This paper proposes a new method for evaluating the seismic performance and fragility of large underground structures. A typical underground subway station consisting of a two-story and three-span structure was used as the research subject. Considering the variation of sites and the uncertainty of input ground motions, we developed a finite element model of a nonlinear dynamic soil-underground structure interaction system. Based on the incremental dynamic analysis method, the nonlinear seismic responses of the subway station structure were calculated for 900 cases. Python (software) was used to accelerate the processing of the large number of numerical simulation data. Based on the seismic damage characteristics of an underground structure, this paper proposes a new concept of average seismic damage value to evaluate the damage condition of the underground structure to overcome the inadequacies induced by an expert’s intuitive judgment. Meanwhile, the random forest prediction model was adopted to predict the seismic performance levels (SPLs) of the underground structure, and a non-parametric test was performed to verify the correlation between the degree of seismic damage and the inter-story drift ratios (IDR) of the large underground structure. This proved that the IDR could describe the seismic damage of shallow-buried underground structures; we advanced a precise quantification system of the SPL for shallow-buried subway station structures with two-story and three-span using probability statistics. The peak ground velocity (PGV) is more suitable than the peak ground acceleration (PGA) for use as the seismic intensity measure (IM) for large underground structures when the stiffness of the soil foundation becomes soft. In addition, the seismic fragility curves of the shallow-buried subway station structure were constructed and analyzed using the developed quantification system for the SPL.

Fragility analysis of nuclear power plant structure under real and spectrum-compatible seismic waves considering soil-structure interaction effect

Both the real and spectrum-compatible seismic waves are widely used as input loads in the seismic assessment of critical structures in engineering applications, which are also allowed by international codes. However, the effect of the real seismic waves and spectrum-compatible seismic waves generated by different methods on the dynamic responses of structures has not been thoroughly emphasized. This study focused on quantitatively comparing the dynamic responses and fragility of the AP1000 nuclear power plant under real and spectrum-compatible seismic waves. Real and spectrum-compatible seismic waves generated by the modification and synthetic methods were used to perform the time history analysis. The effects of three input motion types on a high-accuracy soil–structure interaction system model were investigated based on various dynamic response indexes. The fragility assessment and maximum tension strain contours of the AP1000 nuclear power plant subjected to the three types of seismic waves were also presented to evaluate the influence of the input motions. The results revealed that spectrum-compatible seismic waves can cause larger dynamic responses than real seismic waves at the same peak ground acceleration level. Additionally, although some response indexes, such as strain energy, are sensitive to the input motions when the nuclear power plant is in a nonlinear state, the generation methods of spectrum-compatible seismic waves have insignificant effects on most dynamic response indexes, fragility assessment, and damaged zone locations.

Parameter Sensitivity Analysis of the Seismic Response of a Piled Wharf Structure

To investigate the seismic response characteristics of piled wharf structures, a numerical model of the soil-structure interaction system is established. Extensive fiducial error and grey correlation analyses are also conducted to obtain the grey correlation degree sequence of the internal force of piled wharf structure and deformation, as well as the acceleration of surrounding soils. The results show that the peak acceleration at the typical point of the soil is more sensitive to the variations in friction angle and ground motion intensity, while the lateral extreme displacement is the most sensitive to the variations in the elastic modulus of the soil. The grey correlation sequences of the peak acceleration and lateral extreme displacement at the feature points of the soil around the pile greatly vary, indicating that the key factors of the different sequences control the target parameters corresponding to them. The sensitivity of the internal force of the pile foundation of the pier structure to the ground motion intensity and friction angle is more sensitive than the elastic modulus and cohesion. This presented parameter sensitivity analysis procedure for the seismic response of piled wharf structures can provide a reference for the seismic design of piled wharf structures, as well as for disaster prevention prediction.

Artificial Intelligence-Enabled Interactive System Modeling for Teaching and Learning Based on Cognitive Web Services

The future of modern education and web-based learning is inherently associated with the advancement in modern technologies and computing capacities of new smart machines, such as artificial intelligence (AI). AI is a high-performance computing environment powered by special processors that use cognitive computing for machine learning and data analytics. There are major challenges in online or web-based learning, such as flexibility, student support, classification of teaching, and learning activities. Hence, this paper proposes smart web-based interactive system modeling (SWISM)based on artificial intelligence for teaching and learning. The paper aimed to categorize learners according to their learning skills and discover how to enable learners with machine learning techniques to have appropriate, quality learning objects. Furthermore, local weight, linear regression, and linear regression methods have been introduced to predict the student learning performance in a cloud platform.

PLANNING OF SPATIAL DEVELOPMENT IN TIMES OF WAR AND RECONSTRUCTION: A VISION FOR UKRAINE

In 2022, Ukraine became the object of full-scale russian aggression, which led to human casualties and destruction, and landscape degradation. The final consequences of the hostilities are yet to be assessed, while the need for large-scale reconstruction of the country and its regions is once again evident. In this context, a comprehensive vision of the principles of the development of territories in the post-war period is of particular relevance. The article pays attention to the framework requirements for the planning process in Ukraine and the peculiarities of the documents to be developed at the national and local levels. It has been emphasized that in view of European integration, the General Scheme of Planning of the Territory of Ukraine is the most important document which defines conceptual solutions for planning and rational use of the territory of our state, maintaining a full-fledged living environment, ensuring sustainable development, environmental protection, historical, architectural and cultural sites, determining state priorities and conditions for the development of individual regions and settlements. It should be formed as an interactive modeling system of state management that will determine the strategy for the spatial development of Ukraine as part of the European planning space. The key directions for updating the existing General Scheme have been identified. The processes of reforming urban planning documentation at the local level have been analyzed, with special attention to the proposed integrated recovery programs. The importance of further introduction into the planning process of methods related to the assessment of territories and impacts on the environment and public health has been emphasized.

Stability and Hopf bifurcation of a tumor–immune system interaction model with an immune checkpoint inhibitor

In this paper we study a three-dimensional tumor–immune system interaction model consisted of tumor cells, activated T cells, and immune checkpoint inhibitor anti-PD-1. Based on the uncontrollable character of tumor cells in the absence of immune response and treatment, the growth of tumor cells is assumed to be exponential. We discuss the distribution of equilibria qualitatively and study the stability of all possible equilibria with and without anti-PD-1 drug. When no drug is applied, the model has a tumor-free equilibrium and at most one tumorous equilibrium. Biologically, there exists a threshold dT1 for the death rate dT of T cells: when dT≥dT1 tumor cells will keep growing; when dT<dT1 tumor cells may be eradicated for some positive initial values and keep growing for some other positive initial values. For the case with anti-PD-1 treatment, the model has at most five tumor-free equilibria and two interior equilibria. Our analysis indicates that there exists a threshold γA1 for the intravenous continuous injection γA: when γA≤γA1 the fate of tumor cells is the same as the case with no drug applied; when γA>γA1 the model may exhibit bistable phenomena and periodic orbits. Furthermore, we establish the existence of local Hopf bifurcation around the interior equilibrium and determine the stability of the bifurcating periodic orbits. Our simulations show that the model exhibits a stable periodic orbit which implies the long term coexistence and balance of the tumor and immune system.

Strategy optimization of district energy system in case of sudden demand response or power accident

With the wide application of regional centralized cooling (heating) system in the world and the growing maturity of energy supply technology, the focus of system optimization gradually transforms from technical optimization to strategic optimization to attain the common goals of economy and energy saving. Aiming at the operation strategy model of power grid interactive district energy system based on time-of-use (TOU) price proposed in previous research, this paper proposes new objective equations and constraints to explore the strategic deployment of district energy system when accepting the power grid requirements to reduce or increase the power load directly to improve the economy and energy efficiency of centralized cooling (heating) system. The modified optimization strategy model is used to respond to sudden demand response or power accidents. The strategy model can be directly controlled by the power grid, and the TOU price is no longer the main factor affecting the formulation of the strategy. In the face of sudden demand response or power accidents, the operation strategy optimization model proposed in this paper can guarantee the energy supply demand of users and optimize the economic benefits and energy efficiency of the systems. The operation strategies under various optimization objectives can be obtained through the simple input of energy loss of the pipeline and user cooling or heating load. The proposed model is suitable for the load allocation of energy system with single energy supply form and for the strategy optimization of multi energy coupling system. The accuracy and validity of the proposed model under various optimization objectives are verified based on experiment and simulative research.

A tripartite model system for Southern Ocean diatom-bacterial interactions reveals the coexistence of competing symbiotic strategies

Southern Ocean (SO) diatoms play an important role in global carbon flux, and their influence on carbon export is directly linked to interactions with epiphytic bacteria. Bacterial symbionts that increase diatom growth promote atmospheric carbon uptake, while bacterial degraders divert diatom biomass into the microbial loop where it can then be released as carbon dioxide through respiration. To further explore SO diatom-bacterial associations, a natural model system is needed that is representative of these diverse and important interactions. Here, we use concurrent cultivation to isolate a species of the ecologically-important SO diatom, Pseudo-nitzschia subcurvata, and its co-occurring bacteria. Although vitamin-depleted, axenic Pseudo-nitzschia grew poorly in culture, addition of a co-isolated Roseobacter promoted diatom growth, while addition of a co-isolated Flavobacterium negatively impacted diatom growth. Microscopy revealed both bacterial isolates are physically associated with diatom cells and genome sequencing identified important predicted functions including vitamin synthesis, motility, cell attachment mechanisms, and diverse antimicrobial weapons that could be used for interbacterial competition. These findings revealed the natural coexistence of competing symbiotic strategies of diatom-associated bacteria in the SO, and the utility of this tripartite system, composed of a diatom and two bacterial strains, as a co-culture model to probe ecological-relevant interactions between diatoms and the bacteria that compete for access to the phycosphere.

Learning anisotropic interaction rules from individual trajectories in a heterogeneous cellular population

Interacting particle system (IPS) models have proven to be highly successful for describing the spatial movement of organisms. However, it is challenging to infer the interaction rules directly from data. In the field of equation discovery, the weak-form sparse identification of nonlinear dynamics (WSINDy) methodology has been shown to be computationally efficient for identifying the governing equations of complex systems from noisy data. Motivated by the success of IPS models to describe the spatial movement of organisms, we develop WSINDy for the second-order IPS to learn equations for communities of cells. Our approach learns the directional interaction rules for each individual cell that in aggregate govern the dynamics of a heterogeneous population of migrating cells. To sort a cell according to the active classes present in its model, we also develop a novel ad hoc classification scheme (which accounts for the fact that some cells do not have enough evidence to accurately infer a model). Aggregated models are then constructed hierarchically to simultaneously identify different species of cells present in the population and determine best-fit models for each species. We demonstrate the efficiency and proficiency of the method on several test scenarios, motivated by common cell migration experiments.

Stochastic Analysis of Train Running Safety on Bridge with Earthquake-Induced Irregularity under Aftershock

As a type of urban life project in China, bridges need a certain capacity of trains running safely after an earthquake to ensure and guarantee transportation on railway lines, post-disaster reconstruction and relief work. Since aftershocks may occur after the main shock, the earthquake-induced irregularity and aftershock intensity are fully considered, based on the running safety index in the seismic design of bridges. However, there is a lack of research on the running safety of trains after an earthquake; it is mainly judged on experience, and lacks theoretical basis. In this paper, the established finite element model of a train bridge interaction system with symmetry was considered. The point estimation method (PEM) combined with moment expansion approximation (MEA) is used for random calculation of the Housner Intensity (HI). Furthermore, running safety indexes were analyzed and the running safety performance of a simply supported bridge with symmetry was assessed under a post-earthquake condition. Then the limit value, to ensure the traffic safety performance after an earthquake, is calculated based on stochastic analysis. The HI can be calculated with full consideration of the randomness of aftershock intensity and structural parameters. On this basis, a calculation method of the HI that considers the randomness of aftershock intensity is proposed. This study can be helpful for the performance-based design of symmetric railway structures under post-earthquake conditions.

Application of Speech Interaction System Model Based on Semantic Search in English MOOC Teaching System

In order to improve the effect of English MOOC teaching, this study combines the semantic search algorithm to construct an English MOOC teaching system to promote the interactive effect of English teaching. Moreover, this study analyzes a DOA estimation method based on sparse iterative covariance and an improved method, and no prior knowledge of noise is required to use this method in noisy data scenarios. In addition, this study constructs an English interactive teaching system based on semantic search. Finally, this study uses the course resources of the MOOC platform to teach students, perform organizational collaboration, and answer the questions. The research shows that the speech interaction system model based on semantic search proposed in this study has a better application effect in the English MOOC teaching system.