Similarity Structure Analysis Research Articles

FEM simulation of dynamic response of flexible busbar systems under alternating short-circuit currents

This paper investigates dynamic responses of flexible busbar systems under balanced three-phase alternating short-circuit (SC) currents using finite element method (FEM) simulations. In current industry design standards and practices, a simplified static approach is usually adopted to estimate the SC effects, which is valid only for regular structures and often leads to overly conservative results due to the fact that the configurations of the busbar system are usually over-simplified. A flexible busbar system is geometrically similar to a suspension bridge, which involves geometry-nonlinear behavior of flexible busbars (sometimes called cables or conductors), making analytical solutions of such problems complicated. Five different simulation scenarios are included in order to investigate effects of number of subconductors per phase, dropper and insulator, spacer, and pinch. The pinch effect is modeled via setting up contact pairs. It is found that the short circuit has a dominant effect on twin-subconductor systems, but not on single-subconductor systems. The inclusion of droppers, insulators, and spacers for twin-subconductor systems is found to decrease the structural responses in general. The phenomenon of pinch is clearly captured. It is found that the structural response is more conservative if the system does not include the consideration of pinch. The approach adopted in this study can be extended to analysis of similar structures, such as transmission lines under SC, as well as for busbar systems with irregular supporting structures.

Performance evaluation of a seismic strengthening applied on a masonry school building by dynamic analyses

With its unreinforced masonry structural system, Münevver Şefik Fergar Primary School has been analyzed and retrofitted by the Istanbul Project Coordination Unit, IPKB in Istanbul. The applied strengthening is mainly composed of the addition of reinforced concrete layers to the masonry walls by shotcreting. This study is performed to monitor the variation of the dynamic properties of the building through the constructional works and evaluate the effects of the performed retrofitting. For this aim, six sets of operational modal analysis type dynamic identification, starting from the original building and ending with the retrofitted building, were performed to extract the dynamic properties of the building. To discuss the effectiveness of retrofitting efficiently, numerical analyses have also been conducted. The original and retrofitted form of the building has been modeled by finite element modeling technique and Eigenvalue analyses were performed to obtain the dynamic properties of the building numerically for both phases. The comparison of the dynamic characteristics of the original and retrofitted building enabled the assessment of the efficiency of the applied seismic strengthening. Moreover, the experimentally and numerically obtained results were compared. It is seen that, while both experimental and numerical results proved the effectiveness of the performed retrofitting to increase the dominant frequencies of the building, the difference in their quantity was worth noting and should be accounted for seismic analysis of similar structures.

Investigating Chinese students’ motives for intercultural interactions in a Chinese internationalized university

ABSTRACT This study explores the motives of host students’intercultural interactions in a Chinese academic context, which advocates internationalization of education. Three hundred and sixteen Chinese university students in an internationalized comprehensive university who reported that they had intercultural interactions responded to a self-designed questionnaire about their motives to interact with international students. Exploratory factor analyses (EFA) identified five factors: Communication Experience, Cultural Exchange, Help-Seeking, Language Enhancement and Task Fulfillment, which explained a total variance of 72.083%. The second study sought to test and verify that survey, and two hundred and five valid Chinese university student questionnaires were analyzed. Confirmatory factor analysis (CFA) indicated that the derived five-factor structure fit the data well. Similarity structure analysis (SSA) of the second dataset was then conducted to visually detect the interrelated structure of the five factors. These factors suggest that the broad motivations for using English in intercultural interactions match those of foreign language learning. These findings can contribute to both future research designs and ways that relevant parties might promote intercultural interactions toward building intercultural competence.

How Best to Define Antisemitism? A Structural Approach

Abstract: In the current discussion about definitions of antisemitism, the empirical social sciences have been marginalized. Groups of well-intentioned experts make decisions without considering the real-life experiences and perceptions of Jewish people—those who are impacted by antisemitism. I advocate returning the decision to the people, attributing greater weight in defining antisemitism to the actual perceptions of the victims—bottom-up rather than top-down. As a basis for a valid definition, we need to demonstrate these perceptions empirically. This paper presents a structural analysis of the 2018 Fundamental Rights Agency (FRA) Survey. The study, conducted through the internet, included over 16,000 self-identified Jews in 12 European Union countries. I review the findings regarding the main contents of antisemitic expressions, the channels of transmission of antisemitism, and the identity of perpetrators. Using Similarity Structure Analysis (SSA), I suggest a new and better analytic typology of the main patterns of perceptions of contemporary antisemitism.

Static and Dynamic Analysis of Coupled Vibration of Suspension Bridge Structure Under Earthquake Action

This article investigates the coupled vibration problem of suspension bridge structures under earthquake action, and conducts static and dynamic analysis using computer algorithms. In terms of static analysis, complex structures are divided into many small elements, and the stress and deformation of each element are calculated through finite element analysis, thereby obtaining the static characteristics of the entire structure. In terms of dynamic analysis, the seismic response analysis method based on time history considers seismic action as a time-varying external excitation, and calculates and simulates the dynamic response of the suspension bridge structure. In order to achieve efficient and accurate calculations, this article also adopts optimization algorithms and numerical calculation methods. Through a comprehensive study of statics and dynamics analysis, the key characteristics and regularities of coupled vibration of suspension bridge structures under earthquake action have been obtained. These research results not only provide important theoretical guidance and technical support for related engineering practices, but also provide useful references and inspirations for dynamic analysis and optimization design of similar structures. Meanwhile, using computer algorithms and simulation software for static and dynamic analysis can significantly reduce analysis costs and time, improve analysis accuracy and efficiency, and have broad application prospects.

Hiding in plain sight: The discovery of complete genomes of 11 hypothetical spindle-shaped viruses that putatively infect mesophilic ammonia-oxidizing archaea.

The genome of a putative Nitrosopumilaceae virus with a hypothetical spindle-shaped particle morphology was identified in the Yangshan Harbour metavirome from the East China Sea through protein similarity comparison and structure analysis. This discovery was accompanied by a set of 10 geographically dispersed close relatives found in the environmental virus datasets from typical locations of ammonia-oxidizing archaeon distribution. Its host prediction was supported by iPHoP prediction and protein sequence similarity. The structure of the predicted major capsid protein, together with the overall N-glycosylation site, the transmembrane helices prediction, the hydrophilicity profile, and the docking simulation of the major capsid proteins, indicate that these viruses resemble spindle-shaped viruses. It suggests a similarly assembled structure and, consequently, a possibly spindle-shaped morphology of these newly discovered archaeal viruses.

Real-Time Stress Field Prediction of Umbilical Based on PyEf-U-Net Convolutional Neural Network

Stress field analysis is an essential part of umbilical component layout design. The stress field analysis of an umbilical, via numerical simulation, has commonly been applied in practical engineering. The high economic and time cost associated with numerical simulation and analysis of the stress field in an umbilical has been replaced by data-driven, deep-learning-based, real-time computational methods. In this study, a novel Pyramidal Efficient U-Net (PyEf-U-Net) network is proposed to predict the stress field distribution of the umbilical. The input dataset is obtained via the Differential Evolution-Generalized Lagrange Multiplier (DE-GLM) method, which is entered into the network for training, with a detailed discussion of the effects of hyperparameters such as optimizer, learning rate, and loss function on the performance of the network. The experimental research demonstrates that the proposed PyEf-U-Net can accurately predict the stress field of the umbilical in real time with a prediction accuracy of 94.2%, which is superior to other deep learning networks. The proposed method can provide an effective way for rapid mechanical analysis and design of the umbilical in practical engineering, while the method can be extended to the mechanical analysis and design of other similar marine engineering equipment structures.

Characteristics and factors of mode families of axial turbine runner

Axial turbines are widely used in hydropower systems. Owing to the complex hydraulic excitation force during operation, its flow-passing components, particularly the runner, are prone to severe vibrations. To further understand the vibration of the runner under different excitation forces, this study systematically investigated the modal characteristics of an axial turbine runner through numerical simulation using the example of a prototype Kaplan runner, including a shaft. The finite element method (FEM) and acoustic-structure coupling method were used to solve the natural modes of the runner in vacuum and the added mass effect of water, respectively. It was found that the modes of cantilever-blade structures without a shaft are mainly represented as vibrations of the blades, which can be classified into a series of mode families based on the single-blade modes, corresponding to a series of frequency bands with very small widths. The composition of members in each mode family depended strictly on the number of blades with a clear rule. For axial turbines, the modal vibration of the shaft and blades is prone to coupling, which leads to abnormal changes in some modes in the mode family, resulting in the scattering of the natural frequencies and greatly improving the possibility of resonance. The law of mode coupling was revealed, and the effects of the blade opening and bearing stiffness on the mode coupling and frequency bandwidth were explored. The stiffness of the bearing close to the runner significantly affected the frequency bandwidths. The greater the stiffness, the smaller are the bandwidths. This study can provide a reference for resonance cause analysis and vibration avoidance design of axial turbines and similar structures.

Nonlinear vibration and stability analysis of a flexible beam-ring structure with one-to-one internal resonance

The nonlinear dynamic characteristics of a flexible beam-ring structure under fundamental harmonic excitation are systematically investigated. The nonlinear partial differential governing equations of motion for the beam-ring structure are derived by using Hamilton's principle and discretized into two coupled ordinary differential equations including quadratic and cubic nonlinearities by Galerkin's technique. The potential internal resonance relationship of the beam-ring structure is recognized through analyzing the mode shapes and linear frequencies. The method of multiple scales is utilized to approximately analyze the dynamic system and yield a set of autonomous equations under the case of 1:1 internal resonance and a primary resonance. The amplitude-frequency characteristics and the stability of the steady-state responses are studied numerically. The frequency-response curves show that some parameters of the amplitude-frequency equations have significant contributions to the nonlinear responses near resonance of the beam-ring structure. Finally, the bifurcation diagram is obtained and the Poincare map, power spectra and the largest Lyapunov exponent are used to identify the nonlinear dynamic behaviors of the beam-ring structure. From the numerical simulations, it is found that there exist typical nonlinear phenomena such as multi-value solutions, jumps, bifurcations, multiple periodic and chaotic motions in the beam-ring system. This work also proposes a reference for nonlinear modeling and dynamic analysis of similar complex structures.

Effect of Construction Errors in Cable Forces of Single-Story Orthogonal Cable Network Structures Based on GA-BPNN

The construction process of cable net structure is complicated, which leads to the strong randomness of construction errors. The safety state of the cable net structure is very sensitive to construction errors. Obtaining the coupling relationship between construction errors and cable force response efficiently and accurately is critical to developing the construction technique of cable structures. This paper proposed an analysis method based on a genetic algorithm optimized back propagation neural network (GA-BPNN) to judge the influence of construction error on the cable force of single-layer orthogonal cable network structures. Taking the speed skating stadium of the 2022 Winter Olympic Games as the research object, this paper analyzed the structure form of the venue. According to the characteristics of cable network structure and GA-BPNN calculation, the principle of construction error analysis was put forward. The influence of construction errors of load-bearing cables and stable cables on cable force response was analyzed. The influence degree of different component errors on structural cable forces was obtained, and the most unfavorable key components were obtained. For the key components, the influence trend of different construction errors on cable force was analyzed, and the fitting formula was given. Driven by GA-BPNN, it can realize the analysis of structural and mechanical responses under the action of multi-type, multi-component, and multi-combination construction errors. The results show that the research method efficiently and accurately obtains the performance law of structural cable force under the influence of construction error, effectively predicts the influencing factors of the structural safety risk, and effectively avoids structural safety accidents caused by construction error. The construction errors analysis method based on GA-BPNN proposed in this paper can provide a reference for similar structural analysis and application.

The phytochrome-interacting factor DcPIF3 of carrot plays a positive role in drought stress by increasing endogenous ABA level in Arabidopsis

The phytochrome-interacting factor (PIF) subfamily of basic helix-loop-helix (bHLH) transcription factors plays a critical role in plant growth and development. However, there has been no detailed report on the PIFs in carrot. In this study, we present the identification and characterization of DcPIF gene family in carrot (Daucus carota L.). Phylogenetic analysis indicated that PIFs from carrot and other five plant species could be divided into four groups supported by similar gene structure and motif analysis. Expression profiles showed that all DcPIF genes were tissue-specific and could be induced by drought or abscisic acid (ABA) treatment except DcPIF7.1, among which DcPIF3 was the most responsive. The DcPIF3-overexpressed Arabidopsis plants exhibited more tolerance to drought stress, with higher antioxidant capacity and lower malondialdehyde content after drought treatment than wild type plants. Further stress tolerance assays revealed that DcPIF3 plays a positive role in drought stress by increasing endogenous ABA level and promoting the expression of ABA-related genes. Our results can enrich the understanding of DcPIF family genes and lay a foundation for further investigation of DcPIF3 function to defend against drought stress in carrot.

Palaeoecological features of Lower Asselian (Lower Permian) carbonate skeletal mounds in the Pisanyi Kamen’ section (Un’ya River, Northern Urals)

AbstractAmong the many Upper Carboniferous and Lower Permian reef structures that are known worldwide, a Lower Permian 360 m long succession of reefal rocks in the Urals, interpreted as representing skeletal mounds, stands out for its complexity. The abundance of lime mud material, both in the skeletal mounds and in the adjacent sediments, indicates that they grew below fair‐weather wave base. An important feature of these Lower Permian organic buildups in the Urals is the widespread development of synsedimentary biologically induced cements, which often prevail in the rock volume. One of the most representative (and unique) skeletal mounds sequences in the Northern Urals is the Pisanyi Kamen’ section located on the Un'ya River. This paper aims to identify changes in the character of the palaeocommunity in the Pisanyi Kamen’ section. In the skeletal mounds development in the Lower Asselian interval of the Pisanyi Kamen’ section, seven events are distinguished. These are: (a) stabilisation of a soft sea floor by bryozoans and heterotrophic microbes; (b) colonisation of a hard sea floor by bryozoans and the appearance of abundant bioinduced cements; (c) displacement of bryozoans by a phylloid algae community; (d) appearance of a higher diversity community; (e) the mound top reaching the fair‐weather wave base; (f) collapse of the ecosystem; and (g) recurrent colonisation of a hard sea floor by phylloid algae. This work summarises the current state of knowledge regarding the Lower Permian skeletal mounds structure of the Northern Urals. The description of the ecological succession offers a new tool for the analysis of similar structures.

Involute spline couplings in aero-engine: Predicting nonlinear dynamic response with mass eccentricity

This work presents a nonlinear dynamic model considering the multi-tooth meshing behaviour and mass eccentricity of an involute spline coupling to tackle the serious problem of involute spline failure, in aviation power transmission systems. The dynamic meshing force is calculated for the same. Based on this, the influence of different mass eccentricities on the nonlinear dynamic response of the spline coupling was investigated in aero-engines. The results show that when the mass eccentricity is small, its impact on the system is insignificant. When the eccentricity reaches a certain value, the quasi-periodic and chaotic state appears alternately. Meanwhile, it can be concluded that the acceleration-frequency spectrum during the multi-periodic phase is an approximation of the working frequency with the accuracy affected by multiple teeth engagements. This was validated by the vibration experiments of the involute spline coupling. The proposed model, which considers the multi-tooth meshing behaviour and the mass eccentricity provides a reference model for the dynamic analysis of similar structures. The nonlinear dynamic response results attained lay a good theoretical foundation for fretting damage analysis and precise designs for involute spline couplings.

Second-order analysis of lattice booms considering restraint from the web members

Lattice booms, used in mobile cranes, are welded using slender high-strength steel tubes, and their carrying capacity is determined through the local stability of the chords. However, of the two methods for calculating it, the overall stability formula of axially compressed members is too conservative, and geometrically nonlinear analysis with imperfections is too complicated to apply. To achieve a more accurate and simple calculation of the local chord stability, a second-order analysis considering restraint from web members and initial geometric imperfections is proposed. This study demonstrates that web members not only reduce the maximum chord deflection but also supply a restraint moment for the chords, thereby reducing the maximum stress of the chords, which was ignored or partially ignored in the past. A numerical example is presented to verify the effectiveness and correctness of the second-order analysis of the maximum stress on the chords presented in this paper. This method can be extended to the design and analysis of other similar lattice structures.

COERÊNCIA, COMPLEXIDADE E NOVIDADE PERCEBIDAS EM DISPOSITIVOS DE PULSO PARA CORREDORES

Este artigo apresenta uma pesquisa que teve por objetivo analisar os efeitos da coerência, complexidade e novidade de dispositivos de pulso esportivos para corredores na Qualidade Visual Percebida. Foi usada a Teoria das Facetas para o delineamento da pesquisa e os métodos de Sistema de Classificação Múltipla e Análise de Estrutura de Similaridade (Similarity Structure Analysis - SSA) para, respectivamente, a coleta e a análise dos dados obtidos. As evidências empíricas apontam que as três categorias de dispositivos de pulso tomadas para estudo mostraram-se aderentes à avaliação proposta, que os participantes são mais influenciados por dispositivos de pulso para corredores com contraste baixo (coerência alta), complexidade moderada e preferem o estilo típico em relação à Qualidade Visual Percebida, e que inexiste consenso dos resultados entre os corredores masculinos e femininos da população amostral abordada.

Tools of the trade: MicroCT reveals native structure and functional morphology of organs that drive caterpillar\u2013ant interactions

Caterpillars of many lycaenid butterflies are tended by ants that offer protection from predators and parasitoids. Specialized structures such as glands, ciliary organs and chitinous ornamentation in caterpillars play key roles in the underlying tactile, acoustic, and chemical communication between caterpillars and ants. Although the ecological, evolutionary, and behavioural aspects of these interactions are well studied, the mechanisms (i.e., the functional morphology) that drive the specialized interactive organs are poorly characterized. We used advanced X-ray microtomography (MicroCT) to delineate internal, native morphology of specialized larval dew patches, nectar glands, and tactile ciliary organs that mediate interactions between Crematogaster ants and caterpillars of the obligate myrmecophilous Apharitis lilacinus butterfly. Our non-destructive MicroCT analysis provided novel 3-D insights into the native structure and positions of these specialized organs in unmatched detail. This analysis also suggested a functional relationship between organ structures and surrounding muscles and nervation that operate the glands and tactile organs, including a ‘lasso bag’ control mechanism for dew patches and muscle control for other organs. This provided a holistic understanding of the organs that drive very close caterpillar–ant interactions. Our MicroCT analysis opens a door for similar structural and functional analysis of adaptive insect morphology.

Jewish Perceptions of Antisemitism in the European Union, 2018: A New Structural Look

AbstractThis paper aims at providing a new systemic contribution to research about perceptions of antisemitism/Judeophobia by contemporary Jews in 12 European Union countries. The perspective – the viewpoint of the offended side – has been less prominent relatively in research literature on antisemitism. The data analysis demonstrates the potential power of Similarity Structure Analysis (SSA) as a better theoretical and empirical tool to describe and conceptualize the contents of chosen research issues. After a brief review of some methodological problems in the study of antisemitism, this paper will re-elaborate data first published in the report of the 2018 FRA study Experiences and Perceptions of Antisemitism – Second survey on Discrimination and Hate Crimes against Jews in the EU (FRA 2018a). Topics include the perceived importance of antisemitism as a societal issue, the contents of anti-Jewish prejudice and discrimination, channels of transmission, perpetrators of offenses, regional differences within Europe, and the role of antisemitism perceptions as a component of Jewish identification. Special attention is paid to the distinction between cognitive and experiential perceptions of antisemitism, and to the typology of practical, populist, political, and narrative antisemitism.

A COMPLEXIDADE E A COERÊNCIA VISUAL NA AGRADABILIDADE PERCEBIDA EM SALAS DE AULA PARA ENSINO SUPERIOR


 
 
 Objetiva-se avaliar a agradabilidade percebida em salas de aula para ensino superior. A Teoria das Facetas estruturou a investigação, que utilizou o questionário para coletar dados, a Análise da Estrutura de Similaridade (SSA) e uma tabela de distribuição de frequência para interpretá-los. Os resultados corroboram parcialmente com as sugestões teóricas.
 
 

ANALYSIS OF COMBINED PLATES WITH ALLOWANCE FOR CONTACT WITH ELASTIC FOUNDATION

The paper covers the problems of combined plates with circular base and consisting of a few sections with different laws of thickness variation. Analytical methods of analysis of similar structures are not yet devel­oped. The present work suggests the analytical method for solving of the stated problems, the contact with the elas­tic subgrade is also considered. The above-mentioned approach is shown on the example of the analysis of the bot­tom of the cylindrical reservoir, resting on the elastic subgrade. The inner part of this construction is represented by the ring plate of variable thickness which increases along the direction from the internal boundary. The outer part is represented by the ring plate of the constant thickness. The influence of the elastic basis and the upper part of the reservoir is taken into consideration. The solutions for stresses and deflections of the combined plate are given in closed form in terms of Bessel functions. The conditions of the plate’s sections conjugation are fulfilled.

Eco-friendly approach utilizing green synthesized nanoparticles for paper conservation against microbes involved in biodeterioration of archaeological manuscript

Potential high bio-deterioration of certain microorganisms due to their metabolic activities on organic materials causes serious problems in the conservation of cultural heritage. This study focuses on establishing an efficient conservation strategy against microbial deterioration using biosynthesized nanoparticle (NPs). Isolation, identification, and characterization of microorganisms involved in deterioration of archaeological manuscript dating back to 17th century (1677 A.D) were conducted. Eleven bacterial species and fifteen fungal species were obtained and identified using 16S rRNA and ITS sequences, respectively. All strains exhibited potent cellulolytic activity. Bacillus subtilis strain (B3) and Penicillium chrysogenum strain (F9) achieved the highest cellulolytic activity amongst obtained bacterial and fungal strains. Paper models conservation effect of biosynthesized silver and zinc oxide NPs against strain (B3) and strain (F9) was evaluated. Microbial growth inhibition, color change according to CIE L*a*b* color space, fourier transform infrared spectroscopy (FT-IR) were assessed. Furthermore, morphology and the elemental component of paper models were analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Silver NPs achieved better results than zinc oxide NPs for paper preservation. Application of 1.0 or 2.0 mM silver NPs exhibited the best preservation effect on the paper models achieving 100% microbial inhibition (bacteria and fungi, respectively). Moreover, NPs-treated paper models showed slight color change and exhibited similar structural analysis as original papers. These results showed the potentiality of this green strategy to be applied for conservation of cellulose-constructed cultural heritage.