Global Behavior Research Articles

THE MOTIVATION OF PRACTICING SPORTS DANCE DURING PHYSICAL EDUCATION LESSONS IN ORDER TO IMPROVE THE SELF-IMAGE

Background. Motivational dynamics is always manifested at the level of global behavior, which means that understanding the motivational orientation of behavior requires a systemic view of it. Objectives. Sports dance - whose specific means we used in the experimental study, are effective ways to develop the self-image, the motivational system and the motivation to achieve the self-image. 70 subjects participated in the research, students from different faculties within the University of Bucharest, based on registration in the sports dance class. Among them, 50 female students and 20 male students, aged between 19 and 25, first-year students at the University of Bucharest. All of them opted for the sports dance class at the beginning of the 2022-2023 academic year. Sports dance lessons were held throughout the academic year according to the curriculum. Methods. The observation method: were monitored the indicators related to the efficiency of the execution, the improvement of the posture, of the body attitude, the efficiency of the communication, the relationship with the others, as relevant elements for the studied phenomenon. In addition to direct observation, the video camera and the computer were used. Speaking: using dialogue to obtain useful information. For the present research, the preferred subjects are: knowledge of the particularities of the motivational system; hierarchical organization of motives; knowledge of the conditional determinative and inhibiting factors for practicing of sports dance; evaluation and knowledge of the relationship between achievement motivation and self-image. Questionnaire-based survey: the questionnaire was developed to study self-image and self-esteem. It was developed and applied in order to study the importance that the subjects give to the sports dance practiced in the physical education class for the development of the motivation to realize the self-image. Statistical-mathematical method – statistical-mathematical processing of the data resulting from the questionnaire. Graphical representation method: Microsoft Excel was used. Results. The obtained results were ranked according to the score, tabulated, interpreted and presented graphically. Conclusion. The processing of the subjects results from the initial and final testing, highlights the awareness that has occurred on the benefits that the practice of physical exercises, in general and sports dance, in particular, brings to personal development. From the results of the study, it emerged that Sports Dance develops social intelligence, interpersonal relationships, communication ability, emotional intelligence, the ability to make voluntary effort, perceptive qualities.

Underwater Line Monitoring Using Optimally Placed Inclinometers

Underwater monitoring presents challenges related to maintaining a continuous power supply and communication, necessitating the use of a smaller number of sensors to effectively cover the entire line. An underwater line tracking method is proposed to evaluate global behaviors and stresses in real time. The method employs angles at several points on the line, as well as displacements and curvatures at both ends. In this method, any line displacement, angle, and curvature are expressed as Fourier series, and Fourier coefficients are obtained by utilizing sensor data. Then, the behavior of any line location is assessed. In addition, to reduce the number of sensors and improve accuracy, optimal inclinometer locations are determined by a genetic algorithm. The proposed line tracking algorithm was validated through two numerical examples; one with an inclined tunnel and one with a marine steel catenary riser attached to a Floating Production Storage and Offloading (FPSO) vessel. Through these examples, the proposed algorithm was proven to capture global behaviors accurately when optimally located sensors are used. In the riser monitoring case, the optimized sensor placement with eight intermediate sensors achieved an average mean distance error of 1.91 m, which is lower than the 2.65 m error obtained with ten intermediate sensors without optimization.

Tailoring smart hydrogels through manipulation of heterogeneous subdomains

The mechanical interactions among integrated cellular structures in soft tissues dictate the mechanical behaviors and morphogenetic deformations observed in living organisms. However, replicating these multifaceted attributes in synthetic soft materials remains a challenge. In this work, we develop a smart hydrogel system featuring engineered stiff cellular patterns that induce strain-driven heterogeneous subdomains within the hydrogel film. These subdomains arise from the distinct mechanical responses of the pattern and film domains under applied mechanical forces. Unlike previous studies that incorporate reinforced inclusions into soft matrices to tailor material properties, our method manipulates the localization, integration, and interaction of these subdomain building blocks within the soft film. This enables extensive tuning of both local and global behaviors. Notably, we introduce a subdomain-interface mechanism that allows for the concurrent customization and decoupling of mechanical properties and shape transformations within a single material system—an achievement rarely accomplished with current synthetic soft materials. Additionally, our use of in-situ imaging characterizations, including full-field strain mapping via digital imaging correlation and reciprocal-space patterns through fast Fourier transform analysis of real-space pattern domains, provides rapid real-time monitoring tools to uncover the underlying principles governing tailored multiscale heterogeneities and intricate behaviors.

Modal identification of wind turbine tower based on optimal fractional order statistical moments

AbstractIn vibration testing of civil engineering structures, the first two vibration modes are crucial in representing the global dynamic behavior of the structure measured. In the present study, a comprehensive method is proposed to identify the first two vibration modes of wind turbine towers, which is based on the analysis of fractional order statistical moments (FSM). This study offers novel contributions in two key aspects: (1) theoretical derivations of the relationship between FSM and vibration mode; and (2) successful use of 32/7‐order displacement statistical moment as the optimal FSM to identify wind turbine tower modes, by combining with noise resistance analysis, sensitivity analysis, and stability analysis, respectively. Using the proposed method, the FSM was first used to identify the modal vibration of wind turbine towers. By obtaining the response of the structure on the same vertical line, FSM was then calculated to estimate the corresponding structural modal vibration. Considering other influencing factors in the field test, the modal identification results of this index under different excitation forms and noise conditions were analyzed based on numerical simulation and verified with field wind tower test data. The results of the evaluation show that the proposed statistical moments of can accurately identify the first two vibration modes of wind turbine towers. This presents a new robust method for modal vibration identification, that is, simple and effective in its implementation.

Global and Local Shear Behavior of the Frozen Soil–Concrete Interface: Effects of Temperature, Water Content, Normal Stress, and Shear Rate

The interface between soil and concrete in cold climates has a significant effect on the structural integrity of embedded structures, including piles, liners, and others. In this study, a novel temperature control system was employed to conduct direct shear tests on this interface. The test conditions included normal stress (25 to 100 kPa), temperature (ranging from 20 to −6 °C), water content (from 10 to 19%), and shear rates (0.1 to 1.2 mm/min). Simultaneously, the deformation process of the interface was continuously photographed using a modified visual shear box, and the non-uniform deformation mechanism of the interface was analyzed by combining digital image correlation (DIC) technology with the photographic data. The findings revealed that the shear stress–shear displacement curves did not exhibit a discernible peak strength at elevated temperatures, indicating deformation behavior characterized by strain hardening. In the frozen state, however, the deformation softened, and the interfacial ice bonding strength exhibited a positive correlation with decreasing temperature. When the initial water content was 16% and the normal stress was 100 kPa, the peak shear strength increased significantly from 99.9 kPa to 182.9 kPa as the test temperature dropped from 20 °C to −6 °C. Both shear rate and temperature were found to have a marked effect on the peak shear strength, with interface cohesion being the principal factor contributing to this phenomenon. At a shear rate of 0.1 mm/min, the curve showed hardening characteristics, but at other shear rates, the curves exhibited strain-softening behavior, with the softening becoming more pronounced as shear rates increased and temperatures decreased. Due to the refreezing of interfacial ice, the residual shear strength increased in proportion to the reduction in shear rate. On a mesoscopic level, it was evident that the displacement of soil particles near the interface exhibited more pronounced changes. At lower shear rates, the phenomenon of interfacial refreezing became apparent, as evidenced by the periodic changes in interfacial granular displacement at the interface.

Seismic in-plane behavior of composite masonry walls strengthened with cold rolled steel sheets

The seismic behavior of masonry walls strengthened by cold rolled steel sheets is numerically evaluated in this study using finite element modeling in ABAQUS. Cold-rolled steel sheets cover two sides of an unreinforced masonry wall and are bolted together to form a composite masonry wall. The behavior of the composite masonry walls is compared to that of the corresponding unreinforced masonry walls with various failure mechanisms. The finite element models of the unreinforced masonry walls are validated through experimental data in the literature. Then, cold-rolled steel sheet-strengthened walls are simulated, and variations in strength, ductility, and failure mode are investigated. A thorough sensitivity analysis is conducted on the effects of the aspect ratio, boundary condition, axial load ratio, steel sheet thickness, and connection bolt configuration on the in-plane strength and failure mode of the walls. It is observed that the steel sheets affect the local and global behavior of the masonry walls and change their failure modes. The use of through-thickness bolts to connect steel sheets to the masonry wall provides a composite action between steel sheets and the masonry wall against in-plane lateral loads. The cold-formed steel sheets not only resist a portion of the lateral load but also significantly increase the lateral strength of the masonry walls and the ductility of the whole wall system. Based on the analysis results it can be concluded that strengthening masonry walls with cold-rolled steel sheets is a promising technique for the seismic improvement of existing conventional masonry buildings and for the design of new masonry buildings.

Modelado de paredes de mampostería confinada: revisión de métodos y aplicación utilizando macroelemento discreto

One of the main challenges assessing masonry structures is numerical simulation. An overview and classification of the current developments and available techniques for nonlinear analysis of confined masonry structures is presented. As an exploratory study, an application of a numerical model using a Discrete Macro Element Method was carried out. It consisted on the calibration of mechanical parameters for representing the capacity curve and damage progression of a confined masonry wall tested under quasi static cyclic load. Then a sensitivity analysis was carried out. It has been found that global behavior is well captured by the model regarding strength and deformation. However, failure mode at confining elements was not consistent with the observed damage. Calibration has been made only for one experimental test; thus, conclusions are only valid for this set of experimental results. It is considered that the Discrete Macro Element Method is suitable not only to reproduce the global behavior of complete buildings, which is its original purpose, but also it may be used to study element behavior with appropriate modifications. ILIA: Investigaciones Latinoamericanas en Ingeniería y Arquitectura, No. 01, 2024: 108-114.

Deep learning as Ricci flow.

Deep neural networks (DNNs) are powerful tools for approximating the distribution of complex data. It is known that data passing through a trained DNN classifier undergoes a series of geometric and topological simplifications. While some progress has been made toward understanding these transformations in neural networks with smooth activation functions, an understanding in the more general setting of non-smooth activation functions, such as the rectified linear unit (ReLU), which tend to perform better, is required. Here we propose that the geometric transformations performed by DNNs during classification tasks have parallels to those expected under Hamilton's Ricci flow-a tool from differential geometry that evolves a manifold by smoothing its curvature, in order to identify its topology. To illustrate this idea, we present a computational framework to quantify the geometric changes that occur as data passes through successive layers of a DNN, and use this framework to motivate a notion of 'global Ricci network flow' that can be used to assess a DNN's ability to disentangle complex data geometries to solve classification problems. By training more than 1500 DNN classifiers of different widths and depths on synthetic and real-world data, we show that the strength of global Ricci network flow-like behaviour correlates with accuracy for well-trained DNNs, independently of depth, width and data set. Our findings motivate the use of tools from differential and discrete geometry to the problem of explainability in deep learning.

China’s container freight prices on the global behavior of inflation rate after COVID-19

The main objective of this article is to analyze the relationship between increases in freight costs and inflation in the markets due to the increases reflected in the prices of the products in some economies in destination ports such as the United States, Europe, Japan, South Africa, the United Arab Emirates, New Zealand and South Korea. We use fractionally integrated methods and Granger causality test to calculate the correlation between these indicators. The results indicate that, after a significant drop in inflation in 2020, probably due to the confinement caused by the pandemic, the increases observed in inflation and freight costs are expected to be transitory given their stationary behavior. We also find a close correlation between both indicators in Europe, the United States and South Africa.

Onboard multivariate hazard assessment for UIKKU chemical tanker by Gaidai reliability method

The current study outlines a novel multimodal structural reliability methodology, suitable for naval dynamic systems, that are either numerically simulated, or directly physically measured. Cross-correlations between the system's principal/key dimensions/components, along with the high dimensionality of complex naval dynamic systems, are not easily addressed by existing reliability methods, that are mostly univariate or bivariate. The objective of this study had been to apply a novel reliability/hazard assessment methodology to UIKKU chemical tanker onboard dynamic measurements to demonstrate the efficiency of the proposed multimodal structural reliability methodology. Current investigation utilized onboard measured ice loadings, exerted on the UIKKU tanker hull and propulsion devices during its Arctic voyage. Onboard dynamic data recordings then were interpreted to gain knowledge about dynamic load levels. The hull of UIKKU had been instrumented so that ice-induced loads/stresses on vessel shell plating had been monitored at various key locations, both in longitudinal as well as in vertical directions, along the vessel’s hull. Longitudinal bending stresses at several locations on the vessel hull and vessel vertical accelerations had been measured to analyze global vessel behaviour when colliding e.g., moderately heavy ice ridges. In addition to UIKKU onboard measurements onboard, Russian partners had instrumented icebreaker vessel Capitan Dranitsyn to real-time measure strains/stresses within ice belt grillage, located at the vessel’s bow. Icebreaker vessel Capitan Dranitsyn acted as escort icebreaker during the whole Arctic voyage. Obtained results may be utilized to harmonize IACS Polar ship rules. In the current study, the onboard measuring system along with measured results, during the whole voyage have been briefly represented.

Normas ambientales voluntarias, acciones de mitigación nacionalmente apropiadas y Pacto Verde

The increased voluntary environmental standards in coffee production have been a relevant issue, especially in sustainability and global value chain behavior. Likewise, measures such as Nationally Appropriate Mitigation Actions (NAMA) and the European Union's Green Deal influence this sector. Through a literature review, this article analyzes the interrelations between voluntary standards, NAMA, and the potential to comply with Green Deal requirements, as well as the impact on the productive sector. Standards can contribute to sustainable development goals and emissions reduction, but they are not the ultimate solution to improve the conditions of primary producers. From a market access perspective, productive organizations that have applied sustainability standards and countries with NAMA strategies for the coffee sector are better prepared to comply with the Green Deal. However, the need for public policies to support the sectors, the generation of adequate financing mechanisms, and prospective studies to improve the positioning in the value chains continue to be necessary elements of action that must be strengthened in the short and medium term. Finally, there is still pending conciliation within the World Trade Organization on how these measures will be incorporated into its operating structure.

A model of mechanical loading of the lungs including gravity and a balancing heterogeneous pleural pressure.

Recent years have seen the development of multiple in silico lung models, notably with the aim of improving patient care for pulmonary diseases. These models vary in complexity and typically only consider the implementation of pleural pressure, a depression that keeps the lungs inflated. Gravity, often considered negligible compared to pleural pressure, has been largely overlooked, also due to the complexity of formulating physiological boundary conditions to counterbalance it. However, gravity is known to affect pulmonary functions, such as ventilation. In this study, we incorporated gravity into a recent lung poromechanical model. To do so, in addition to the gravitational body force, we proposed novel boundary conditions consisting in a heterogeneous pleural pressure field constrained to counterbalance gravity to reach global equilibrium of applied forces. We assessed the impact of gravity on the global and local behavior of the model, including the pressure-volume response and porosity field. Our findings reveal that gravity, despite being small, influences lung response. Specifically, the inclusion of gravity in our model led to the emergence of heterogeneities in deformation and stress distribution, compatible with in vivo imaging data. This could provide valuable insights for predicting the progression of certain pulmonary diseases by correlating areas subjected to higher deformation and stresses with disease evolution patterns.

Global existence and asymptotic behavior of affine solutions to Navier–Stokes equations in ℝN with degenerate viscosity and free boundary

Global existence and asymptotic behavior of affine solutions to Navier–Stokes equations in ℝN with degenerate viscosity and free boundary

Variation of the Passive Film on Compositionally Concentrated Dual-Phase Al0.3Cr0.5Fe2Mn0.25Mo0.15Ni1.5Ti0.3 and Implications for Corrosion

AbstractThe passive film on a dual-phase Al0.3Cr0.5Fe2Mn0.25Mo0.15Ni1.5Ti0.3 FCC + Heusler (L21) compositionally concentrated alloy formed during extended exposure to an applied potential in the passive range in dilute chloride solution was characterized. Each phase, with its own distinct composition of passivating elements, formed unique passive films separated by a heterophase interface. High-resolution, surface sensitive characterization enabled chemical analysis of the passive film formed over individual phases. The film formed over the L21 phase had a higher concentration of Al, Ni, and Ti, while the film formed over FCC phase was of similar thickness but contained comparatively higher Cr, Fe, and Mo concentrations, consistent with the differences in bulk microstructure composition. The passive film was continuous across phase boundaries and the distribution of passivating elements (Al, Cr, and Ti) indicated both phases were independently passivated. Spatially resolved analysis of the surface chemistry of the dual-phase CCA revealed that the cation with the highest composition in passive film formed on the FCC phase was Cr (52.4 at. pct) and for the L21 phase was Ti (53.1 at. pct) despite the bulk concentration of each element being below 20 at. pct in their respective phases. Al, Cr, and Ti were enriched in both phases within the passive film relative to their respective bulk compositions. In parallel studies, single-phase alloys with compositions representative of the FCC and L21 phases were synthesized to evaluate the corrosion behavior of each phase in isolation. The corrosion behavior of the dual-phase alloy showed passivity evidenced by a pitting potential of 0.615 VSCE in 0.01 M NaCl. The pitting potential and other electrochemical parameters suggested a combination of behaviors of both single-phase samples, suggesting that the global corrosion behavior may be represented by a composite theory applied to phases, their area fractions, and interphase length. However, the interphase in the dual-phase CCA was a local corrosion initiation site and may limit localized corrosion protectiveness. The alloy design implications for optimization of second phase structure and morphology are discussed.

Phase Behavior of System Carbon Dioxide + Hydrogen Sulfide

The global phase equilibrium behavior of the CO2+H2S system is discussed in this work for temperatures ranging from 160 K up to the critical region. Solid phases of CO2 and H2S and corresponding equilibria have been modeled by considering either a 4th-order equation of state (also used for the fluid phases) or a solid fugacity model for the pure components combined with an activity coefficient model (both coupled with a reference equation of state for the fluid phases).Phase equilibrium calculations have been performed by the minimization of the Gibbs Free Energy of mixing and compared to existing literature data.The types of pressure-mole fraction phase diagrams that can be encountered in the low-temperature thermodynamic region have been described. The temperature and pressure ranges where the phase behavior of the system changes have been identified and a representative phase diagram is presented for each range.

VLOG: Vehicle Identity Verification Based on Local and Global Behavior Analysis

VLOG: Vehicle Identity Verification Based on Local and Global Behavior Analysis

The comparison of eight different common in vitro and ex vivo environments with in vivo conditions applying model collagen samples: correlation possibilities and their limits

New biomaterials are routinely evaluated for their degradation behaviour in the real body environment. Following the 3R strategy, in vitro simulated body conditions are often preferred. No studies that simultaneously compare such conditions with the real body environment have been conducted to date. Model porous collagen scaffolds were exposed for 21 days to eight different environments: simple salt-based and enzymatic media, human blood plasma, cell culture media with and without human fibroblasts and ex vivo model cortical bone, and subsequently compared with an in vivo environment represented by a pig peritoneum. The mechanical properties of the scaffolds were then determined via uniaxial compression testing, and the structural properties via the micro-CT, weight loss, infrared spectroscopy, X-ray diffraction and histological methods. Interestingly, the various analysed simulated body conditions caused differing alterations in the collagen scaffold characteristics when compared with the real body environment. The mechanical properties were similar during the first 7 days of incubation but diverged after 14 and 21 days. The structural properties varied significantly after just 7 days of incubation. The histological evaluation of the scaffolds exposed to the cellular, ex vivo and in vivo conditions revealed the poor ability of cells to completely populate the scaffolds, accompanied by the massive ingrowth of connective tissue into the in vivo exposed scaffolds, which resulted in their variable global behaviour. In conclusion, the value of in vitro simulated body environments lies in their screening capacity and feasibility; however, direct extrapolation to real body conditions needs to be verified going forward.

Fragility curves of a slender structure fitted with tuned mass dampers subjected to turbulent wind and seismic loading

In the context of structural performance assessment, several studies have employed fragility curves and surfaces to evaluate the damage probability for predefined intensity levels of a single or multiple hazards. Further, some of these studies have considered the use of tuned mass dampers (TMDs) to reduce the response of structures under wind or seismic loading. In this work, fragility curves and surfaces of a slender structure fitted with TMDs subjected to turbulent wind and seismic loading alone and simultaneously are developed. For the numerical analyses, simulated records for wind and earthquake ground motion are considered. For the development of fragility curves and surfaces, three damage states that include local and global behavior of the structure are considered. The analysis results indicate that, for the structure considered, higher probability of damage is found from wind action than from earthquake, and that an important reliability enhancement is achieved with the use of TMDs.

Sensibility Analysis of Traditional Span Frame

ABSTRACT Traditional timber frames may have a complex mechanical behavior regarding to today engineer skills and design standards. For an identical rebuilding as required for the Notre-Dame de Paris Cathedral, accurate modeling must be performed to assess modern reliability. Identical rebuilt means same green oak material, same geometry and timber connections. In the context of the rebuilt of the Notre-Dame carpentry, a part of the timber frame based on the original schemes of the nave extracted from historical graphic document was reproduced. A full-scale replica was erected in order to perform mechanical tests. Through an in-situ monitoring, this structure represents a case study in order to provide data relative to the kinetics of displacements. This investigation allows to evaluate the global behavior of the structure. Based on the finite element method (F.E.M), a dedicated model is used to analyze the sensitivity of the material properties, the beam geometry and the wood-to-wood connections in order to design the testing carried out on the wooden structure. From these full-scale tests, we determine the real stiffness of the carpentry. Then, a retro-analysis was proposed to evaluate the axial stiffness of connections according to the corresponding finite element model, by fitting data to reproduce the real displacements. The study reveals that this property is substantial to describe the global behavior. Furthermore, we carried out in the laboratory an experimental campaign consisting in characterizing traditional joints. The goal was to estimate their stiffness and their specific failure modes by using image correlation. Concomitantly, numerical simulations were developed in order to investigate the dependence of the stiffness according to moisture content variation of oak species. The global research supplies useful tools and results, which may be able to improve the understanding of the mechanical performance of traditional structures and provide valuable information for design purposes.

Comparative behavior of circular precast UHPC columns with hoops and spiral reinforcement

Ultra-high performance concrete (UHPC) offers outstanding mechanical properties that can greatly influence the future of our structures. Despite the remarkable durability and high tensile and compressive strength of UHPC, its widespread use in large structural applications remains limited. This limitation is attributed to several factors such as the relatively high cost of the material and the slow development of large-scale production technology and procedures. In light of these challenges, the objective of this research is two-fold: first, demonstrate the successful fabrication of four full precast UHPC columns using economic mixture and construction-scale production in a precast plant setting, and next, compare the axial behavior of the fabricated circular columns with different transverse reinforcement detailing. The study carefully considers the choice of lateral confinement and spacing along the height of the column (spiral and hoop reinforcement with 1.5 in and 3 in spacing). The paper presents the global and local behavior that include load capacity, stiffness, axial and reinforcement strains, and ductility. The spirally confined column with 1.5 in spacing showed 26 % higher ductility than the counter hoop reinforced column, while both configurations showed a significant increase in ductility of 34 % when the transverse reinforcement spacing is reduced from 3 to 1.5 in. The research shows that the ACI design reduction factor for conventional concrete (0.65) and the accidental eccentricity reduction factor (0.8) for hoops are unnecessarily conservative and might be increased to 0.75 and 0.85, respectively as for the spiral reinforcement in the case of UHPC columns.