Interaction Problems Research Articles

A flow-reconstruction based approach for the computation of hydrodynamic stresses on immersed body surface

This study focuses on obtaining reliable hydrodynamic stresses on the surface of rigid bodies in the simulation of fluid-solid interactions using the diffuse-interface immersed boundary method (IBM). In order to obtain the pressure and velocity gradient information on the immersed boundary, we employ a model to reconstruct the near-boundary fluid flow along the surface normal direction. Different from most existing flow reconstruction models in diffuse-interface IBMs based on the boundary layer approximation, we propose a new reconstruction model relying only on the non-slip velocity and local flow information. With this improvement, the present reconstruction model is theoretically applicable to fluid flows with intermediate Reynolds numbers (with the existence of a laminar boundary layer) and low Reynolds numbers (in the absence of a boundary layer). To examine the validity of the present reconstruction model, we conduct a series of simulations, including the uniform flow past a fixed body and the settling of a rigid body in a quiescent fluid. It is demonstrated that the present reconstruction model has a better performance than existing models in predicting hydrodynamic stresses on the immersed boundary within a wide range of Reynolds numbers from O(1) to O(100). The capability and robustness of the proposed model demonstrate its potential to address fluid-solid interaction problems with a-priori unknown or time-varying Reynolds numbers, such as fully resolved simulations of particle laden flows.

Clip-GCN: an adaptive detection model for multimodal emergent fake news domains

Emergent news is characterized by few labels, and news detection methods that rely on a large number of labels are difficult to apply to learned features for emerging events and are ineffective in coping with less labeled emergent news detection. To address the challenge of limited labeled data, this study first establishes a scenario for detecting breaking news, ensuring that the domain of detecting events is distinct from the domain of historical events. Secondly, we propose the Clip-GCN multimodal fake news detection model. The model utilizes the Clip pre-training model to perform joint semantic feature extraction of image-text information, with text information as the supervisory signal, which solves the problem of semantic interaction between modalities. Meanwhile, considering the domain attributes of news, the model is trained to extract inter-domain invariant features through Adversarial Neural Network ideation, and intra-domain knowledge information is utilized through graph convolutional networks (GCN) to detect emergent news. Through an extensive number of experiments on Chinese and English datasets from two major social media platforms, Weibo and Twitter, it is demonstrated that the model proposed in this paper can accurately screen multimodal emergent news on social media with an average accuracy of 88.7%. The contribution of this study lies not only in the improvement of model performance but also in the proposal of a solution for the challenges posed by limited labels and multimodal breaking news. This provides robust support for research in related fields.

Problems of intercultural interaction at the Embassy of K. G. Machechnin to France in 1654

The article analyzes the problems of interaction with the foreign cultural environment of the embassy of K. G. Machechnin, sent to France in 1653–1654, on the basis of the preserved complexes of Russian and French sources. The embassy had both foreign policy and diplomatic significance for restoring Russia's position in the system of relations between European countries, the messenger had not only to notify the French king about events in Eastern Europe, but also to substantiate the reasons for the outbreak of the Russian-Polish war. At the same time, in his contacts, the messenger did not remain limited to a mission to the king, but also interacted with the Queen Mother, the English Queen in exile, French courtiers, emigrants from the British Isles and Dutch merchants who traded in Russia. The purpose of the article is to analyze the features of intercultural interaction in the context of a new diplomatic history, with special attention to the problems of representation of power, the personality of diplomats and the cultural side of their mission. This emphasis gives the study relevance, due to the little attention in historiography to this mission in the context of a more classical history of international relations. The materials for the study were French court reports on ceremonies, publications in La Gazette and La muze historique, correspondence of French courtiers and article lists of Russian messengers. Conclusions are drawn about the diplomatic and foreign policy significance of the mission, about the existing problems of interaction between Russian and French diplomatic culture in the middle of the XVII century, the influence of the personality of the messenger K. G. Stepmother's view of the process of establishing diplomatic relations, as well as the specifics of transmitting news about the embassy in preserved sources. The results of the study can be used for research on the diplomatic culture of the XVII century, the history of foreign policy and international relations. В статье на основе сохранившихся комплексов русских и французских источников проанализированы проблемы взаимодействия с инокультурной средой посольства К. Г. Мачехнина, направленного во Францию в 1653–1654 гг. Посольство имело как внешнеполитическое, так и дипломатическое значение для восстановления позиций России в системе отношений между странами Европы, гонец должен был не только уведомить французского короля о событиях в Восточной Европе, но также и обосновать причины начинавшейся русско-польской войны. При этом в своих контактах гонец не остался ограничен миссией к королю, но также взаимодействовал с королевой-матерью, английской королевой в изгнании, французскими придворными, эмигрантами с Британских островов и торговавшими в России голландскими купцами. Целью статьи является анализ особенностей межкультурного взаимодействия в контексте новой дипломатической истории с особым вниманием к проблемам репрезентации власти, личности дипломатов и культурной стороне их миссии. Такой акцент придает исследованию актуальность, в связи с небольшим вниманием в историографии к этой миссии в контексте более классической истории международных отношений. В качестве материалов для исследования послужили французские придворные отчеты о церемониях, публикации в изданиях La Gazette и La muze historique, переписка французских придворных и статейные списки русских гонцов. Сделаны выводы о дипломатическом и внешнеполитическом значении миссии, о существовавших проблемах взаимодействия русской и французской дипломатической культуры в середине XVII в., влиянии личности гонца К. Г. Мачехнина на процесс складывания дипломатических отношений, а также об особенностях передачи известий о посольстве в сохранившихся источниках. Результаты исследования могут быть привлечены для исследований по дипломатической культуре XVII в., истории внешней политики и международных отношений.

Correlation between autistic traits and brain functional connectivity in preschoolers with autism spectrum disorder: a resting state MEG study.

Neurophysiological studies recognized that Autism Spectrum Disorder (ASD) is associated with altered patterns of over- and under-connectivity. However, little is known about network organization in children with ASD in the early phases of development and its correlation with the severity of core autistic features. The present study aimed at investigating the association between brain connectivity derived from MEG signals and severity of ASD traits measured with different diagnostic clinical scales, in a sample of 16 children with ASD aged 2 to 6years. A significant correlation emerged between connectivity strength in cortical brain areas implicated in several resting state networks (Default mode, Central executive, Salience, Visual and Sensorimotor) and the severity of communication anomalies, social interaction problems, social affect problems, and repetitive behaviors. Seed analysis revealed that this pattern of correlation was mainly caused by global rather than local effects. The present evidence suggests that altered connectivity strength in several resting state networks is related to clinical features and may contribute to neurofunctional correlates of ASD. Future studies implementing the same method on a wider and stratified sample may further support functional connectivity as a possible biomarker of the condition.

A complex approach to solving the problem of interaction between a rigid double-connected punch and an elastic half-space

A complex approach to solving the problem of interaction between a rigid double-connected punch and an elastic half-space

A conservative discontinuous-Galerkin-in-time (DGiT) multirate time integration framework for interface-coupled problems with applications to solid–solid interaction and air–sea models

In this paper we extend the DGiT multirate framework, developed in Connors and Sockwell (2022) for scalar transmission problems, to a solid–solid interaction (SSI) problem involving two coupled elastic solids and a coupled air–sea model with the rotating, thermal shallow water equations. In so doing we aim to demonstrate the broad applicability of the mathematical theory and governing principles established in Connors and Sockwell (2022) to coupled problems characterized by subproblems evolving at different temporal scales. Multirate time integration algorithms employing different time steps, optimized for the dynamics of each subproblem, can significantly improve simulation efficiency for such coupled problems. However, development of multirate algorithms is a highly non-trivial task due to the coupling, which can impact accuracy, stability or other desired properties such as preservation of system invariants. DGiT provides a general template for multirate time integration that can achieve these properties. To elucidate the manner in which DGiT accomplishes this task, we fully detail each step in the application of the framework to the SSI and air–sea coupled problems. Numerical examples illustrate key properties of the resulting multirate schemes for both problems.

Constructing Pavement Roughness of a Three-Dimensional Bridge in Abaqus for Vehicle Scanning Method

In this study, a procedure for constructing pavement roughness in a three-dimensional bridge subjected to a vehicle using Abaqus is proposed for numerical simulation of vehicle–bridge interaction problems. As the plug-in RufGen, a graphical user interface in Abaqus/CAE for surface interaction, creates a hexahedron with a rough surface and attaches it to the bridge deck, the resulting weight of a bridge model can be much larger than the original one. In the vehicle scanning method, it is essential to keep a finite element bridge model with an unchanged weight after imposing a rough surface on it in consideration of the roughness effect for bridge health monitoring. As such, the proposed procedure is aimed at resolving this issue, with the following two highlights: First, the Toeplitz matrix is introduced to generate a rough surface in three dimensions to ensure the randomness of roughness in the two perpendicular directions under a given roughness profile. Second, a shell-type rough pavement is established for directly using as the bridge pavement or attaching to the bridge deck, which minimizes weight increment in the bridge.

Case Study of Congklak Playing Therapy in Children to Improve Social Interaction Due to Gadget Addiction

Objective: To see the effectiveness of congklak play therapy in increasing social interaction in children because of gadget addiction. Method: The research design used is a case study research method, with a descriptive research type. The research subject used was 1 school-age child client with social interaction problems due to gadget addiction. Result: Subjectively, the client experiences an increase in interaction with the people around him and a decrease in the intensity of his use of gadgets. Clients can better control their emotions, and there is an increase in learning. Likewise, objectively, the client seems to be able to control his emotions, and often interacts with the people around him. Conclusion: After doing research on An. M., the data obtained by the client's mother complains that the client rarely interacts with other people; the client often plays gadgets until he forgets the time; and when the gadget is taken, he often gets angry. The client's mother gets information from the client's school teacher that the client is less cooperative while studying at school. Based on the assessment, the diagnosis that emerged was social interaction disorder. The author conducted an intervention to overcome social interaction disturbances for four days. The intervention that the author has done is to provide congklak play therapy. After the intervention, the client's signs and symptoms of impaired social interaction diminished. The client has often interacted with people around him by using his gadget a little less.

Institutional Regulation of the CIS Observer Mission in Election Campaigns and Coverage of Its Activities in the Media

This study is aimed at studying the institutional, organizational and legal problems of interaction between the media and international observers during elections and referendums in the member states of the Commonwealth of Independent States. The issue of countering foreign interference in the electoral process was not considered in the work.Aim. Eliminate methodological problems in defining the content of the term “international observation”, and proving the need to institutionalize the process of covering the activities of international observers in the media.Tasks. Identify the necessary areas of media activity when covering the activities of international observers during elections and referendums.Methods. The state of the modern election monitoring environment indicates the existence of a fine line between the need to ensure openness of electoral processes and the inadmissibility of interference in the internal affairs of states. It is necessary to identify restrictive thresholds for the activities of the media when covering the processes of international observation of elections and referendums and their institutionalization in relevant advisory documents based on the presumed impartiality of both international observers and the media.Results. The study showed that the most important task of the process of legitimizing the electoral process is to ensure its full coverage of the activities of all its subjects in the media. International monitoring media coverage should cover a wide range of issues throughout the entire electoral process from start to finish, including; activities of observers during the official election campaign before the start of voting; on election day and during the vote counting process; in the period after the elections from the moment the official results are announced until the formation of new authorities. At the same time, at all stages, coverage should cover a wide range of issues of the essence of the electoral process and its management; legal regulation of elections and referendums and existing institutional structures to support the process.Conclusions. Media coverage of the activities of international observers should be considered not only as one of the most important modes of political communication, but also as a means of countering selective absenteeism. Objective and impartial coverage of the activities of international observers in the media can undoubtedly contribute to both the internal political mobilization of the population and the international recognition of the state.

Mapped material point method for large deformation problems with sharp gradients and its application to soil‐structure interactions

AbstractThe material point method (MPM) is often applied to large deformation problems that involve sharp gradients in the solution field. Representative examples in geomechanics are interactions between soils and various “structures” such as foundations, penetrometers, and machines, where the displacement fields exhibit sharp gradients around the soil‐structure interfaces. Such sharp gradients should be captured properly in the MPM discretization to ensure that the numerical solution is sufficiently accurate. In the MPM literature, several types of locally refined discretizations have been developed and used for this purpose. However, these local refinement schemes are not only quite complicated but also restricted to certain types of basis functions or update schemes. In this work, we propose a new MPM formulation, called the mapped MPM, that can efficiently capture sharp gradients with a uniform background grid compatible with every standard MPM basis function and scheme. The mapped MPM is built on the method of auxiliary mapping that reparameterizes the given problem in a different domain whereby sharp gradients become much smoother. Because the reparameterized problem is free of undesirably sharp gradients, it can be well solved with the standard MPM ingredients including a uniform background grid. We verify and demonstrate the mapped MPM through several numerical examples, with particular attention to soil‐structure interaction problems.

Liquid Sloshing in Soil-Supported Multiple Cylindrical Tanks Equipped with Baffle under Horizontal Excitation

The dynamic behavior of liquid storage tanks is one of the research issues about fluid–structure interaction problems. The analysis errors of the dynamics of multiple adjacent tanks can exist if neglecting soil–tank interaction since tanks are typically supported on flexible soil. In the present paper, the dynamics of a group of baffled cylindrical storage tanks supported on a circular surface foundation and undergoing horizontal excitation are analytically examined. For upper multiple tank–liquid–baffle subsystems, accurate solutions to the velocity potential for liquid sloshing are acquired according to the subdomain partition technique. A theoretical model is utilized to portray the continuous sloshing of each tank. For the soil–foundation subsystem, a lumped-parameter model is used to characterize the impacts of soil on upper-tank structures using Chebyshev complex polynomials that present the fitting results of horizontal, rocking, and coupling impedance functions. Then, a model of the soil–foundation–tank–liquid–baffle system is constructed on the basis of the substructure approach. The present sloshing frequencies, sloshing height, and hydrodynamic shear as well as the moment under rigid/soft soil foundations are compared to the available exact results and the numerical results to prove the validity of the present model. The error of the maximum sloshing height between the present and the numerical solutions is within 5.27%; the solution efficiency of system dynamics from the present model is 40–50 times faster than that from the ADINA model. A detailed parameter analysis of the dynamic characteristics and earthquake responses of the coupling system is presented. The research novelty is that an equivalent analytical model is presented, and it allows for investigating the dynamics of soil-supported multiple cylindrical tanks with a baffle, providing acceptable accuracy and high calculation efficiency.

Syntax, vocabulary, phraseology: Aspects of correlation and interaction

This article raises the issues of using an integrative approach with respect to the study of language units, the problems of interaction of syntax, vocabulary and phraseology, and their interpenetration and contact within the framework of the semantic structure of the language as a functioning system. We also consider syntactic units that are in the zone of abstract meanings that ensure the integrity and vital activity of the language. The diachronic aspect of the coverage of the questions posed contributed to the identification of two processes – grammaticalization and lexicalization, which stimulate mutual transitions and borderline positions between principal and auxiliary parts, predicative and nominative parts, mono and polysemantic parts, as well as stable and instable parts in the sentence. The syntactic phraseomodels, analyzed in the article, are frequent in the sphere of hypotaxis when expressing adversarial-concessional, temporal and causal relations. It is especially important that the language has the integrativity of abstract vocabulary and relational semantics, designed to cement and structure speech activity. The syntactic phraseomodels under consideration complicate relational semantics with modal or expressive meanings. The modal component is usually realized through the vocabulary of anthropocentric content, covering the entire spectrum of human speech-psychomental activity, it is represented by separate semantic fields and lexical-semantic groups. Within the framework of expressive contexts, as essential elements are the lexical content of pretexts and the presence of emotive components in their composition. In these phrases, one can see a cause-and-effect relationship between two propositions, the real and potential ones in the subordinate part, although such models often move into the sphere of intensity semantics and the zone of emotiveness. The syntactic phraseomodels under consideration and those of them that have acquired a stable appearance are prone to parceling, budding from the base part and functioning more autonomously in the text. Thus, semantic-syntactic relations interact with abstract vocabulary and have a certain range of emotional-evaluative and modal meanings.

A thin-plate approximation for ocean wave interactions with an ice shelf

A variational principle is proposed to derive the governing equations for the problem of ocean wave interactions with a floating ice shelf, where the ice shelf is modelled by the full linear equations of elasticity and has an Archimedean draught. The variational principle is used to form a thin-plate approximation for the ice shelf, which includes water–ice coupling at the shelf front and extensional waves in the shelf, in contrast to the benchmark thin-plate approximation for ocean wave interactions with an ice shelf. The thin-plate approximation is combined with a single-mode approximation in the water, where the vertical motion is constrained to the eigenfunction that supports propagating waves. The new terms in the approximation are shown to have a major impact on predictions of ice shelf strains for wave periods in the swell regime.

Nonlinear 3D Finite Element Analysis of a Coupled Soil–Structure System by a Deterministic Approach

Fully coupled soil–structure analyses were performed for a building of strategic importance located in the city of Messina (Sicily, Italy). The structure was built after the destructive 1908 earthquake, also known as the ‘Messina and Reggio Calabria earthquake’, which caused severe ground shaking. A parametric study considering three seismograms of this earthquake was performed. Deep in situ and laboratory investigations allowed the definition of the geometric and geotechnical model of the subsoil. Numerical analyses were performed with PLAXIS3D finite element software (Version 21.01.00.479). The Hardening Soil model with small-strain stiffness was accurately calibrated using laboratory and field data. The dynamic response was investigated in terms of accelerations, response spectra, amplification functions, displacements and stress–strain hysteretic loops. The findings show that many aspects must be investigated for the retrofitting of buildings with shallow foundation in areas characterized by a medium to high level of seismic risk: (i) a key role is played by an accurate investigation of the soil; taking into account the specific conditions of the soil, it was possible to investigate its filtering effects; (ii) the dynamic response of the fully-coupled soil–structure system deviates from the free field-site response analysis; (iii) the results reveal the importance of considering the soil nonlinearity in seismic soil–structure interaction problems.

Partitioned analysis of acoustic fluid–solid-saturated porous medium interaction problems by a generalized saturated porous medium model and localized Lagrange multipliers

A partitioned formulation of acoustic fluid–solid-saturated porous medium interaction problems is presented based on a generalized saturated porous medium (GSPM) model and a new localized Lagrange multiplier (LLM) method. In this formula, all various media are modeled as the GSPM and a novel, powerful continuous condition is proposed for the interaction interfaces. This condition applies not only to interfaces of two partitions but also to intersections of simultaneous interactions of any number of media with different porosities. A (u, p) frame is introduced between partitions and the LLM fields are used to connect partitions with the frame. Furthermore, finite element spatial discretization and time integration strategies are provided for both matching meshes and nonmatching meshes. This partitioned formulation is validated numerically by computing the dynamic response of a horizontally layered seawater-seabed-bedrock model subjected to plane waves. The application scenarios for this method include, but are not limited to, the dynamic coupling analysis of marine engineering structures and hydraulic engineering structures. Future work will present and discuss a set of benchmarks and applications that involve the responses of existing dams to seismic excitation.

Development of foreign language communicative needs among students

Relevance. The dynamism of economic and socio-cultural processes in society, significantly expands the boundaries of the possibilities of the modern individual, related to the realisation of individual potential, the achievement of goals. The increasing globalization and technological progress underscore the vital importance of foreign language proficiency for navigating diverse cultural landscapes and succeeding in the globalized job market, necessitating a thorough exploration of the evolving communicative needs among students. Purpose. The purpose of this study is to analyze the development of foreign language communicative needs among students, emphasizing the role of the competence-based approach in fostering these needs. This research aims to identify the key characteristics and methods that enhance students' motivation and ability to engage in intercultural dialogue through foreign language acquisition. Methodology. The methods of theoretical analysis of scientific sources, inductive and deductive methods of generalisation of empirical data available in scientific practice concerning the problem of the development of foreign language communicative needs among students when studying foreign languages are used, in the focus of the implementation of the competence approach. Results. Implementing a competence-based approach significantly contributes to the development of foreign language communicative needs in students. By integrating pedagogical, psychological, social tools, students improve their language skills and become more effective in intercultural interactions, leading to a more harmonious multicultural personality. Conclusions. The article presents scientific data on the implementation of the competence-based approach in the process of developing a foreign language communicative need among students when teaching foreign languages. The presented scientific data on the application of the competence approach, in order to develop foreign language communicative needs of students, will expand the theoretical and methodological aspect of studying the problem of intercultural interaction of a modern personality, clarify the features and means of optimising the cognitive motivation of students studying foreign languages. Keywords: competence approach; foreign language communicative need; educational process; foreign language teaching; students

Numerical Simulation of Compensation Injection Problems Near Deep Excavations

The stress-strain state (SSS) of the “ground foundation – foundation pit under the protection of a fence – compensation injection zone” system is complex, multifactorial and transforming in space. Taking into account a wide range of phenomena when changing the SSS of the soil base is associated with significant difficulties, especially without the use of numerical modeling using software and computer systems. Numerical modeling in the implementation of the finite element method (FEM) for the problems of complex interaction of a soil basis with underground structures during compensatory grouting makes it possible to assign injection zones in any position in space (horizontally, vertically, at an angle), determine the necessary injection parameters to achieve the building lifting of the soil basis when solving the inverse problem. In this study, using examples of numerical modeling of compensation grouting problems near the pit fence with different locations of existing buildings, the authors identified the determining factors affecting the distribution of internal forces in the enclosing structures of the excavation, as well as on the existing structures of the underground structure. The results of comparison of calculations in two-dimensional and three-dimensional formulations are presented, an increase in the bending moment of the retaining wall when carrying out work on compensatory injection by 187-279% is shown for different parameters of the distance to the grouting horizon. The results of the conducted studies confirm the need to take into account the increase in internal efforts during the work on compensatory injection in the structures of the pit fences when assigning reinforcement. In addition, in some cases it is necessary to provide additional protective measures to prevent a negative impact on the constructed underground structures to reduce emergency situations.

On wave-current interaction with a horizontal cylinder near free surface by a fourth-order-accurate finite volume compact solver

We present a numerical solver for dealing with the problem of wave-current interaction with a horizontal cylinder near free surface. The solver solves the filtered Navier-Stokes equations which are discretized using a fourth-order-accurate compact finite volume scheme on a collocated grid. The turbulence effect is modelled by a subgrid-scale model using a large eddy simulation, and the free surface and the cylinder are modelled by a volume of fluid method and a ghost cell immersed boundary method. The pressure-velocity coupling is ensured via a momentum interpolation method. We obtain the hydrodynamic force and its spectra characteristics, dynamic pressure distribution, streamline topology and vorticity patterns with different immersed depths under uniform currents, regular waves and wave-current flows. Validation is performed by comparing the calculated hydrodynamic force with the measured data within one wave period. The results show that the position of vortex shedding and dissipation is different for the cases under different immersed depth in regular waves and wave-current flows. The dynamic pressure around the cylinder as the force reaches its peak value changes with immersed depth. The value and phase of the force are sensitive to immersed depth.

Perilaku Komunikasi Verbal dan Nonverbal Orang Tua dengan Remaja Pengguna Gadget Aktif: Kasus Tiga Keluarga di Gang Rukun Sidoarjo Hilir Kecamatan Tembung

In everyday life, communication is not just about transmitting messages; it involves complex verbal and nonverbal dimensions. The digital era, driven by the advancement of Information and Communication Technology (ICT), has brought significant changes in the way we interact. Its influence is strongly felt among teenagers who are actively involved in using gadgets. Although designed to facilitate communication, gadgets often become a potential source of problems in human interaction. This research uses a qualitative method with descriptive data analysis, focusing on the communication dynamics between parents and teenagers who actively use gadgets. The research results show that the use of the Batak language in verbal communication by parents is the main highlight, highlighting the cultural richness in family interaction. In addition to the verbal dimension, interaction is also observed through nonverbal communication including facial expressions, body movements, and body posture in the context of parent-teenager relationships.

Fluid structure interaction problem for flow past three unequal sized square cylinders at different Reynolds numbers

The flow past three square cylinders of unequal size placed in an inline arrangement is studied using the lattice Boltzmann method at different Reynolds numbers [Re = (u∞ d)/ν] within the range of Re = 120, 150, 160, 175, and 200 for various gap spacings (g = s/d), ranging from 1 to 6. This study focused on the symmetric examination of flow behavior for various gap spacing within the three unequal-sized square cylinders. The main objective of this study was to investigate the effects of Reynolds numbers and gap spacing for flow structure mechanism and vortex shedding suppression in between the gap and down-stream position of all three cylinders. Results are obtained in terms of vorticity contours visualization, drag and lift coefficients, Strouhal number, and physical parameters. In vorticity contour visualization, different flow behaviors are observed, known as flow regimes, and are named according to their characteristics, and they are (i) steady flow regime, (ii) shear layer reattachment flow regime (SLR), (iii) fully developed vortex shedding flow regime, (iv) two-row fully developed vortex shedding flow regime, and (v) fully developed irregular vortex shedding flow regime. The present study also includes a discussion on aerodynamic forces, namely the mean drag coefficient (Cdmean), root mean square of the lift coefficient (Clrms), and Strouhal numbers (St) for three cylinders with sizes d = 20, d1 = 15, and d2 = 10, respectively. The maximum value of Cdmean for the first cylinder (C1) is obtained at (Re, g) = (200, 3) that is, 1.5156, where the existing flow regime is the SLR flow regime, while for C2 and C3, the maximum Cdmean values are examined at critical flow behaviors, where the existing flow regime is a fully developed irregular vortex shedding flow regime. Negative values of Cdmean are also examined for cylinders C2 and C3 at some combinations of (Re, g), attributed to the effect of thrust. Furthermore, it is noticed that the values of Strouhal number are increased with an increment in values of gap spacing. The highest value of the Strouhal number for all three cylinders is observed for C1 at (Re, g) = (120, 5), reaching 0.1556 along with a two-row fully developed flow regime. Furthermore, it is investigated from the present problem that the position of unequal sized square cylinders strongly influenced the flow structure mechanism. The information found and discussed in this study could be effective for structure designing arrangement in the case of three square cylinders of unequal size placed in a horizontal arrangement.