Center Of Gravity Research Articles

Spatial and Temporal Characteristics of Land Use Changes in the Yellow River Basin from 1990 to 2021 and Future Predictions

Studying spatial and temporal characteristics of land use changes and the driving factors in the Yellow River Basin as well as simulating and predicting future land use is crucial for resource management, ecological protection, and regional sustainable development in the Yellow River Basin. Based on the China Land Cover Dataset (CLCD) of the Yellow River Basin from 1990 to 2021, this study employs various methods such as the Mann–Kendall test and sliding t-test, land use dynamics, the land use transfer matrix, the standard deviation ellipse, the center of gravity migration model, and a geographic detector to explore the spatial and temporal characteristics of land use changes and driving forces in the Yellow River Basin over the past 30 years. Additionally, the study predicts land use types in the study area for the year of 2030 by using the Future Land Use Simulation (FLUS) model. The results show the following: (1) From 1990 to 2021, the area of forest, grassland, water, and impervious surfaces increased significantly, while the area of cropland, shrub, barren land, and wetlands decreased significantly. The most actively changing land use types are cropland, grassland, barren land, and impervious surfaces. (2) The center of gravity for shrub and impervious surfaces shifted westward, while wetlands showed a trend of obvious concentrated distribution, and the remaining land use types exhibited stable directional distributions. (3) Economic factors had a stronger driving effect on land use changes than topographic and climatic factors. The land use changes in the Yellow River Basin are influenced by the coordinated driving forces of multiple factors. (4) In 2030, the main land use types in the Yellow River Basin are still expected to be cropland, grassland, and forest. However, there will be a significant expansion of impervious surfaces and forest land, with substantial encroachment on cropland and grassland.

In Search of Covalency Measure of Gd(III)-Ligand Interactions.

Experimental electron density distribution of the [C(NH2)3]3[Gd(EDTA)F2]·H2O crystal was determined. The derived experimental and theoretical (DFT) topological parameters such as ∇2ρc, ρc, bond degree (BD), kinetics, and potential energy were used to study the nature of Gd-O, Gd-F, and Gd-N interactions. The natural charge of the Gd is 1.86; the natural configuration of the cation is [Xe]6s0.134f7.105d0.83, and the covalency of the Gd-L bond is mainly connected with the transfer of charge from the spx ligand orbitals onto the 5d orbitals of the Gd cation. Simultaneously, the donation of charge onto the 6s and 4f orbitals occurs to a lesser extent. Moreover it was found that the donation of the ligand charges onto the Gd(III) is larger for compounds with a lower coordination number. The obtained topological parameters were analyzed in the context of the Gd(III) f-f transition properties, i.e., energy of the excited 2S+1LJ states, Judd-Ofelt intensity parameters, and luminescence lifetimes, of 18 Gd(III) compounds with various O, N, and F donor ligands (DOTA, EDTA, CDTA, DTPA, NTA, EGTA, ODA, F-, H2O, and CO32-). The calculated nephelauxetic β parameter may reflect the penetration degree of electron lone pairs of ligands inside the metal basin. Finally, it was found for the first time that the sum of the Gd(III)-L bond energy (∑EGdL) is correlated with the position of the gravity center of the 8S7/2 → 2S+1LJ transitions and increase of covalency of the Gd(III)-L bonds is associated with decrease of their bond energy. The obtained results may shed light on chemical bonding in systems containing f-elements. Such subtle differences in the covalent contribution to the Ln-L or An-L bond may tune the selectivity of the partitioning processes of lanthanides and actinides.

Spatial-temporal evolution patterns of influenza incidence in Xinjiang Prefecture from 2014 to 2023 based on GIS

Using GIS technology, this study investigated the spatiotemporal distribution pattern of influenza incidence in Xinjiang from 2014 to 2023 based on influenza surveillance data. The study revealed a noticeable fluctuation trend in influenza incidence rates in Xinjiang, particularly notable spikes observed in 2019 and 2023. The results of the 3-year moving average showed a significant long-term upward trend in influenza incidence rates, confirmed by Theil-Sen method (MAD = 2.202, p < 0.01). Global spatial autocorrelation analysis indicated significant positive spatial autocorrelation in influenza incidence rates from 2016 and from 2018 to 2023 (Moran’s I > 0, P < 0.05). Local spatial autocorrelation analysis further revealed clustering patterns in different regions, with high-high clustering and low-high clustering predominating in northern Xinjiang, and low-low clustering predominating in southern Xinjiang. Hotspot analysis indicated a progressive rise in the number of influenza incidence hotspots, primarily concentrated in northern Xinjiang, particularly in Urumqi, Ili Kazakh Autonomous Prefecture, and Hotan Prefecture. Standard deviation ellipse analysis and the trajectory of influenza incidence gravity center migration showed that the transmission range of influenza in Xinjiang has been expanding, with the epidemic center gradually moving northward. The spatiotemporal heterogeneity of influenza incidence in Xinjiang highlights the need for differentiated and precise influenza prevention and control strategies in different regions to address the changing trends in influenza prevalence.

Gait planning and adjustment for a hexapod walking robot with one leg failure

ABSTRACT Gait adjusting is an effective way to solve leg failure problems and is also the foundation of intelligent self-adjustment. This paper takes a hexagonal type of robot as a prototype and proposes a ‘2-2-1’ gait grouping and gait sequence for the one leg failure case based on the ‘4 + 2’ gait. The longitudinal stability margin is used to evaluate the FLF-A and FLF-B gaits with left front leg failure and FLM-A and FLM-B gait with left middle leg failure. The foothold positions are adjusted by changing the median angle of the stance phase of the body-coxa joint in each leg in order to make sure the centre of gravity is in a stable support polygon. The experiments of the robot walking show that the FLF-A gait and the FLM-B gait are more stable than the FLF-B and FLM-A after adjustment. The pitch and roll angles are maintained within − 3° to 3°, which verify the effectiveness of the stance phase leg median position adjustment strategy. This study could be used to do forward pre-adjustment in the case of one leg failure.

Numerical integration of mechanical forces in center-based models for biological cell populations

Center-based models are used to simulate the mechanical behavior of biological cells during embryonic development or cancer growth. To allow for the simulation of biological populations potentially growing from a few individual cells to many thousands or more, these models have to be numerically efficient, while being reasonably accurate on the level of individual cell trajectories. In this work, we increase the robustness, accuracy, and efficiency of the simulation of center-based models by choosing the time steps adaptively in the numerical method and comparing five different integration methods. We investigate the gain in using single rate time stepping based on local estimates of the numerical errors for the forward and backward Euler methods of first order accuracy and a Runge-Kutta method and the trapezoidal method of second order accuracy. Properties of the analytical solution such as convergence to steady state and conservation of the center of gravity are inherited by the numerical solutions. Furthermore, we propose a multirate time stepping scheme that simulates regions with high local force gradients (e.g. as they happen after cell division) with multiple smaller time steps within a larger single time step for regions with smoother forces. These methods are compared for a model system in numerical experiments. We conclude, for example, that the multirate forward Euler method performs better than the Runge-Kutta method for low accuracy requirements but for higher accuracy the latter method is preferred. Only with frequent cell divisions the method with a fixed time step is the best choice.

The use of small-arms stability measures in combat shooting assessments

The acquisition of weapons at scale requires objective measures to discriminate between products and inform decisions. Testing of weapons commonly occurs on known-distance ranges in static positions at static targets using accuracy and timing as the main variables of interest. However, testing weapons in more representative environments may better show variations in ergonomic-related factors such as centre-of-gravity (CoG) changes. This study aimed to examine the utility of weapon accelerations as a measure of stability, understand how stability changes with repeated shots and the responsiveness to changes in the CoG. Eighteen soldiers shot 60 times under four conditions: an unweighted rifle and the addition of a mass fixed at three different positions. A weapon-mounted accelerometer captured the accelerations of the weapon 200 ms before shot release. Twelve stability measures were calculated and reduced via a principal component analysis. Three of these metrics were then assessed for changes over the shots and between the four conditions. Decreased stability occurred over the 60 shots for all conditions, suggesting increasing fatigue. Stability only differed between one pair of conditions with one metric, implying that stability can be maintained with the different weapon configurations.

Investigating the Relationship between Balanced Composition and Aesthetic Judgment through Computational Aesthetics and Neuroaesthetic Approaches

Background: Symmetry is a special kind of balance. This study aims to systematically explore and apply the role of balanced composition in aesthetic judgments by focusing on balanced composition features and employing research methods from computational aesthetics and neuroaesthetics. Methods: First, experimental materials were classified by quantifying balanced composition using several indices, including symmetry, center of gravity, and negative space. An EEG experiment was conducted with 18 participants, who were asked to respond dichotomously to the same stimuli under different judgment tasks (balance and aesthetics), with both behavioral and EEG data being recorded and analyzed. Subsequently, participants’ data were combined with balanced composition indices to construct and analyze various SVM classification models. Results: Participants largely used balanced composition as a criterion for aesthetic evaluation. ERP data indicated that from 300–500 ms post-stimulus, brain activation was more significant in the aesthetic task, with unbeautiful and imbalanced stimuli eliciting larger frontal negative waves and occipital positive waves. From 600–1000 ms, beautiful stimuli caused smaller negative waves in the PZ channel. The results of the SVM models indicated that the model incorporating aesthetic subject data (ACC = 0.9989) outperforms the model using only balanced composition parameters of the aesthetic object (ACC = 0.7074). Conclusions: Balanced composition is a crucial indicator in aesthetics, with similar early processing stages in both balance and aesthetic judgments. Multi-modal data models validated the advantage of including human factors in aesthetic evaluation systems. This interdisciplinary approach not only enhances our understanding of the cognitive and emotional processes involved in aesthetic judgments but also enables the construction of more reasonable machine learning models to simulate and predict human aesthetic preferences.

Spatiotemporal evolution and driving mechanism of Dongting Lake based on 2005–2020 multi-source remote sensing data

As one of the largest inland lakes in China, Dongting Lake has attracted widespread attention owing to its rich natural resources, unique geographical landscape, and important ecological functions. Recently, Dongting Lake has experienced phenomena such as an early dry season and backflow during the flood season. Multi-source remote sensing data and the normalised difference water index (NDWI) threshold method were used to systematically analyse the water area of the lake from 2005 to 2020. Additionally, it employed a centre of gravity migration model and a geographic detector model to investigate the lake's evolution patterns and driving mechanisms. The research identified notable fluctuations in Dongting Lake's water area during this period, with a particularly sharp decline in 2006—from 1509.74 km2 to 815 km2, marking a decrease of 694.74 km2 and a shrinkage rate of 46.01 %. Spatial analysis indicated that the centre of gravity of these water areas changed primarily between Nandashan Town, the Dongting Lake Management Committee, Wanzihu Township, and Qingtan Township, underscoring their significant influence on lake dynamics, including runoff, surface water availability, sediment deposition, and precipitation, all of which displayed strong positive correlations (Pearson coefficients of 0.57, 0.68, and 0.63, respectively), whereas population density showed a negative correlation (Pearson coefficient of −0.56). Furthermore, the study highlighted the substantial impact of the Digital Elevation Model (DEM) and its interaction with slope and aspect on Dongting Lake's evolution, with Q values of 0.537 and 0.543, respectively, emphasising their critical roles in shaping lake area changes and providing a crucial scientific basis for enhancing the understanding and effective management of water resources in the Dongting Lake Basin through comprehensive analysis of its spatiotemporal evolution and driving mechanisms.

Looking backwards, looking forwards: collective and critical conversations on psychology in South Africa

To mark the 30th anniversary of the Psychological Society of South Africa (PsySSA), 11 of PsySSA’s past presidents, along with two facilitators, gathered in early 2024 for a roundtable discussion on psychology in South Africa. This article represents an edited transcript of that conversation. The guiding motif of the discussion – looking backwards, looking forwards – led discussants through the historical temporalities, institutional, professional and disciplinary debates, as well as the political concerns that face and have forged South African psychology. The discussants were specifically concerned with the challenges of unifying organised psychology; the generative forces, conflicts and antagonisms within psychology; psychology’s pedagogical and intellectual developments; and what it means to politicise psychology in and beyond South Africa. In looking ahead, the discussion concluded with an internationalist reflection on how psychology in South Africa contributes to global knowledges and praxes. The conversation was characterised by epistemic, sectoral and political tensions, as well as ambivalences and shifting centres of gravity, all of which reflect the accomplishments made within South African psychology, as well as psychology’s status as a strongly contested and patently unfinished organisational, disciplinary, professional, service and knowledge project.

Remote Sensing Monitoring and Multidimensional Impact Factor Analysis of Urban Heat Island Effect in Zhengzhou City

In the 21st century, the rapid urbanization process has led to increasingly severe urban heat island effects and other urban thermal environment issues, posing significant challenges to urban planning and environmental management. This study focuses on Zhengzhou, China, utilizing Landsat remote sensing imagery data from five key years between 2000 and 2020. By applying atmospheric correction methods, we accurately retrieved the land surface temperature (LST). The study employed a gravity center migration model to track the spatial changes of heat island patches and used the geographical detector method to quantitatively analyze the combined impact of surface characteristics, meteorological conditions, and socio-economic factors on the urban heat island effect. Results show that the LST in Zhengzhou exhibits a fluctuating growth trend, closely related to the expansion of built-up areas and urban planning. High-temperature zones are mainly concentrated in built-up areas, while low-temperature zones are primarily found in areas covered by water bodies and vegetation. Notably, the Normalized Difference Built-up Index (NDBI) and the Normalized Difference Vegetation Index (NDVI) are the two most significant factors influencing the spatial distribution of land surface temperature, with explanatory power reaching 42.7% and 41.3%, respectively. As urban development enters a stable stage, government environmental management measures have played a positive role in mitigating the urban heat island effect. This study not only provides a scientific basis for understanding the spatiotemporal changes in land surface temperature in Zhengzhou but also offers new technical support for urban planning and management, helping to alleviate the urban heat island effect and improve the living environment quality for urban residents.

NDVI Changes and Influencing Factors of Different Soil and Water Conservation Zones in Shandong Province

Exploring the characteristics of vegetation change and its influencing factors is essential to construct an ecological environment. Based on the NDVI dataset from 2000 to 2020, this study analyzed the spatial temporal attributes of NDVI changes in Shandong Province using the Sen trend analysis and the gravity center migration model. Furthermore, the spatial heterogeneity of NDVI and its influencing factors within the whole study area and different soil and water conservation zones were investigated using a Geo-detector model, considering population, hydrological, topographic, soil types, and vegetation types. The results were as follows： ① The NDVI in Shandong Province from 2000 to 2020 showed a fluctuating upward trend with significant seasonal characteristics that varied from different zones. The annual NDVI change showed a trend of single-peak in the Ⅲ-4-2t, Ⅲ-4-1xt, and Ⅲ-5-2w but showed a trend of double-peak in the Ⅲ-5-3fn. ② Regarding the spatial distribution, the NDVI was higher in the west-north and west-south areas and lower in the north and coastal areas. During the 21 years, the primary type of NDVI change was "medium-high coverage → high coverage," especially in the northeastern part of the soil conservation area of the Ⅲ-4-2t, the western part of the Ⅲ-4-1xt, and the ecological maintenance area of the Ⅲ-5-2w. Overall, 61.47% of the area had a positive trend of NDVI change with the gravity center of high coverage mitigating to the northeast, and the ecological environment was improved. ③ Soil types and population density were the dominant factors affecting NDVI in Shandong Province, with q values of 0.174 and 0.130, respectively. The chief factor in the Ⅲ-5-3fn, Ⅲ-4-2t, and Ⅲ-4-1xt was population density, with q values higher than 0.22, and the dominant factors in the Ⅲ-5-2w were soil types and vegetation types, with q values of 0.326 and 0.227, respectively. The interaction of the two factors enhanced the influence of the single factor, and the relationship between the influencing factors showed two-factor enhancement and nonlinear enhancement. The q-value of population density ∩ relative humidity was the highest, with a value of 0.257 in the Ⅲ-5-3fn. The q-value of population density ∩ soil types was the highest in the Ⅲ-4-2t and Ⅲ-4-1xt, reaching 0.297 and 0.378, respectively. The q-value of soil types ∩ vegetation types was the highest, with a value of 0.444 in the Ⅲ-5-2w. The results are expected to provide valuable references for improving the ecological environment of Shandong Province and lay a scientific foundation to make different conservation strategies for the individual soil and water conservation zones.

Spatio-Temporal Distribution Characteristics of Buddhist Temples and Pagodas in the Liaoning Region, China

Buddhist culture in Liaoning has a long and rich history. The continuous spread of Buddhism has promoted the development of Buddhist architecture, leaving us a rich architectural art heritage. Furthermore, it has also profoundly influenced China’s architectural characteristics, social culture, and economic development. This paper takes Buddhist temples and pagodas in Liaoning as the research objects and uses methods such as the geographic concentration index, nearest neighbor index, kernel density estimation, and standard deviation ellipse to analyze their spatio-temporal distribution characteristics and influencing factors across different periods. 1. Temporal distribution. During the Liao Dynasty (907–1125 AD) and the Qing Dynasty (1636–1912 AD), the construction of Buddhist temples and pagodas was the highest, with a linear increase in the Qing Dynasty. 2. The overall spatial distribution of Buddhist temples and pagodas in Liaoning is uneven, showing an agglomeration distribution state. The distribution status of different periods was different, and the Ming (1368–1644 AD) and Qing dynasties (1636–1912 AD) showed obvious aggregation distribution. The overall state is “more in the west and less in the east” and “more in the north and less in the south”. 3. In different periods, the spatial distribution direction of Buddhist temples and pagodas in Liaoning was relatively obvious and was southwest–northeast, and the center of gravity gradually shifted to the northwest. 4. The kernel density of different periods presents the density distribution and area of each period. The overall distribution is dense to scattered and then to highly dense. 5. The spatio-temporal distribution characteristics of Buddhist temples and pagodas in Liaoning are mainly composed of deep-seated political factors, rapid economic development and stable social environment, diverse culture, natural geography, cultural relics protection, and the artistic value of Buddhist architecture in the Liaoning region.

Effectiveness of Prenatal Gentle Yoga and Effleurage Massage in Low Back Pain Third Trimester Pregnant Women

Background: Pregnant women often complain of low back pain, typically becoming more intense as pregnancy progresses due to changes in posture, such as increased lordosis and a shift in the center of gravity. If not addressed, this pain can negatively impact the quality of life by interfering with daily activities. However, Prenatal gentle yoga and effleurage massage are effective ways to avoid back pain. Objective: To examine how women in their third trimester of pregnancy might manage their lower back discomfort using effleurage massage and gentle yoga. Methods: In the quasi-experimental design of this research, selective sampling approaches are used. Additionally, a two-group pretest-posttest design is utilized, and there is no control group provided. The research was conducted in the PMB Ika Winoto area, and forty expectant mothers with back pain who were in the third trimester were among them. The Effleurage treatment consisted of a 30-minute massage session, with each movement performed for about 10 minutes, administered twice to each participant. Prenatal yoga sessions were also conducted twice a week, with each session lasting 60 minutes. A numerical rating scale, also known as the NRS, was used to assess the amount of back pain that the patient was experiencing). To fully examine the data, a Wilcoxon Signed Rank Test was used. Results: P-values for the Effleurage massage group and the Prenatal Gentle Yoga group were 0.000 and 0.005, respectively, according to the analysis findings. The average reduction in low back pain intensity was 9.86 for the Effleurage massage group and 6.87 for the Prenatal Gentle Yoga group. Conclusion: Both pregnancy gentle yoga and effleurage massage work well to relieve low back pain. Regarding how pregnant women who are still in the third trimester of their pregnancy should be treated for low back pain, the effleurage massage method works better than prenatal yoga. Therefore, for expectant mothers who are suffering from low back discomfort, these techniques represent effective alternative medicines that are simple to use and have few adverse effects.

Optimization of the handling behaviour of an electric car by adjusting the kinematic gains of suspension

Abstract In this paper, within the scope of development of an electric car on a vehicle platform that is borned as internal combustion engine is presented. The vehicle dynamics behaviour changes due to the change of weight distribution and centre of gravity. Replacing the internal combustion engine with an electric motor, plus the addition of the battery moves the center of gravity towards the rear of the vehicle. Due to the increase in the rear axle load, the tendency of the vehicle to oversteer increases. To overcome this phenomenon, the rear suspension kinematic gains (camber, toe change due to vertical movement of the wheel) are adjusted thanks to the multi-link suspension. In the fist part of the study the platform is measured and Admas Car model is correlated depends on measured handling metrics. Subsequently, centre of gravity changes are applied to the verified Adams Car model. Also main platform handling metrics is defined as design targets and rear axle kinematic gains are defined as design parameters. A design of experiments (DOE)-based optimization study was performed via Adams®/Insight commercial software to achieve required handling metrics which satisfy design targets. Kinematic gains of the suspension system is analyzed via Adams car and sensitivity deepens on harpoints is determined. Design space for hardpoints is determined depends on mechanical design. The lowest and highest points are determined on the x, y and z axis and experiment list are designed according to DOE. Maneuvers that are for measuring the handling metrics are performed one after the other by changing the parameters according to the boundary conditions comes from DOE. A regression mathematical model is obtained and optimum parameters are calculated for the handling behaviour optimisation. Optimum parameters are applied on the Adams Car model again and handling manoeuvres are repeated. Results show that, although weight distribution changes, handling behaviours remain the same as based platform.

Dynamics of a falling plate at low Reynolds numbers

Free-falling of objects in fluids is universal in nature and engineering. The falling styles of the falling object are affected by the properties of both the object and the fluid. Based on the assumption that the final state of a free-falling object at low Reynolds numbers is stable and equivalent to that of a fixed object with incoming flow, we utilize the results for the fixed plate to interpolate and obtain the state of the falling plate. It is found that the plate would exhibit multiple stable falling solutions. The number of stable falling solutions is dependent on the location of the gravity center of the plate. The distribution of the multi-solution region is affected by both Archimedes number (Ar) and the density ratio (m*). The results of the actual fall of the plate do not always agree with those obtained by the static interpolation method due to the fact that the fall of the plate is a dynamic process. We simulate the falling behaviors of plates whose center of gravity is located in the multi-solution region for different initial release angles θ0. According to the falling behaviors of the plate, there are four regions that are observed and denoted in the multi-solution region: (1) single stable region; (2) bistable region; (3) single stable and fluttering region; and (4) bistable and fluttering region. The effects of Ar,m*, and the dimensionless moment of inertia I* of the plate on the distribution of the four regions are evaluated.

Aerodynamic Characterization of a Hypersonic Projectile Using Acceleration-Based Measurements and Numerical Methods

Armor-piercing fin-stabilized projectiles stand out by their exceptionally high slenderness ratios and ground-level flight at super- and hypersonic speeds. As space constraints limit the integration of measurement equipment into such slender test models, nonintrusive measurement techniques become favorable. The present analysis demonstrates a renewed approach to the free-flight technique, which sets models into unconstrained flight through the test section. It enabled the evaluation of the quasi-steady drag, lift, and pitching moment characteristics, and, to some extent, also the dynamic pitch damping characteristics. An alternative to the free-flight technique is the free-oscillation technique, which limits the motion to a rotation around the center of gravity. The free-oscillation technique allowed a higher-fidelity analysis of the static and dynamic pitching moments. Both methods were based on the analysis of the accelerations derived from trajectory tracking. This acceleration-based approach enabled the evaluation of the highly nonlinear characteristics. The high slenderness of the investigated projectile leads to a significant contribution of the viscous forces to the overall drag. These viscous forces are sensitive to the laminar-turbulent boundary-layer state, as well as the thermal boundary conditions. The application of a high-resolution schlieren system enabled the assessment of the local laminar-turbulent boundary-layer state, while the use of low- and high-enthalpy testing facilities enabled the assessment of the aerothermal influence. Steady-state Reynolds-averaged Navier–Stokes simulations, which included laminar-turbulent transition modeling, were employed to replicate the results of the experimental efforts.

Working space planning for wheeled robot overturning stability

Abstract Mobile manipulators have been widely used in the field of building construction. Typical features of construction robots include crossing various rugged terrains in construction sites, carrying heavy payloads, and performing tasks in a large workspace, which may lead to unstable posture or overturning. The tipping of the mobile manipulator, especially when carrying a payload, will cause danger to the surrounding environment and staff, leading to the termination of the task. The purpose of this study is to establish a real-time tipping prediction system, which can be used to avoid tipping of mobile manipulators. By employing the CAD model of the robot and parameters such as the center of gravity and direction, we can ascertain and assess the instability of the robot and the overturning algorithm, thus providing early warning and averting any potential danger.

Reliabilities of three methods used to evaluate computer-assisted mandibular reconstructions using free fibula flaps

ObjectiveThis study compared the reliabilities of three different methods used to calculate surgical deviations after mandibular reconstructions using free fibular flaps. Study designThis retrospective study involved 35 patients who underwent computer-assisted mandibular reconstructions using free fibula flaps. The deviations between the virtual surgical plans and the postoperative results were independently analyzed by two researchers using three distinct methods. In Method A, the fibular axis, the center of gravity, and the osteotomy plane served as landmarks when measuring surgical deviations. In Methods B and C, manually designated points were used to measure errors in the fibular length and intersegmental angle. The primary outcome variables were the intraclass correlation coefficients (ICCs) that revealed the inter-rater agreements for all three methods. ResultsThe use of Method A was associated with good agreement in terms of the fibular length deviation (ICC = 0.765) and intersegmental angle (ICC = 0.897); both were higher than those afforded by Methods B (ICC = 0.158 and 0.108) and C (ICC = 0.406 and 0.463). The measurements of the fibular transfer osteotomy deviation (ICC = 0.888), linear deviation (0.926), and angular deviation (0.958) were very reliable. ConclusionsMethod A afforded the highest reliability in clinical practice when evaluating surgical deviations after mandibular reconstruction using fibular flaps.

Nonlinear dynamic finite element analysis of vehicle impacts into road restraint systems

Despite that the safety of cars is continuously increasing, improving the safety of road transportation remains a key issue of modern society. The design of suitable road restraint systems plays an important role. As the tests of barriers are technically demanding and expensive, and road traffic intensity is continuously growing, it is crucial to develop advanced models that would make it possible to explore various scenarios under which road vehicles may accidently impact into the road restraint barrier. The submitted study focuses on the use of nonlinear dynamic finite element analysis (NLDFEA) in the reliability assessment of road restraint systems, with a particular focus on steel barriers subjected to impacts by heavy vehicles. The outcomes of theoretical analyses are compared with the results in a compiled unique database of full-scale road barrier impact test results. It appears that a good match between crash test results and the validated NLDFEA model can be achieved, differences being mostly within a range of 10 %. When modelling the crashes of buses and HGVs, it is particularly important to model correctly shape and geometry of the front and impacting side of the vehicle, tyre sizes, wheelbase and overall truck dimensions, and position of the centre of gravity of the vehicle including trailer and cargo. Recommendations for subsequent research studies and for practical applications are finally provided.

Kinematic Analysis of the Final Release position of elite Archer

The purpose of the study was kinematical analysis of an Elite archers. In present study total sample five Indian International level male Recurve category Archers was selected by Purposive sampling technique from SAI Archery training Center Sonipat. The age of the subjects was between 24 (± 5) years, hight of the subjects 6.0` (± 5 Inch), participation year between 2016-2022, shooting FITA score between 650-720 in archery was selected as a subjects for the study. According to Casio EX-F1 high speed camera was used, which have frequency from 60-300 frames per second (f/s). The data were recorded from Superior view, Lateral view, Anterior view and Medial view. The distance between shooting line and target is 70 meter. Shooting line is passed horizontally through the Center of Gravity box, Center of Gravity box is a square box drown with the measurement of 1×1 m, Center of Gravity box is equally divided into 4 parts. A straight line is passed vertically on it and a horizontal line which is shooting line and is drawn 70 meter apart from the target. The distance between bull eye of the target and the floor surface is 5 feet. Siliconcoach Pro8 update motion analysis software and Tracker motion analysis software was used for kinematical analysis of at the time of final release position in archery. Descriptive statistic was used. To find out multi correlation between dependent variable performance on target 1-10 (bull eye) in points and independent variables (selected linear variables). The significant correlation was found between Height of body Center of Mass, Height of body Center of Gravity, Height of Projectile and obtained value (-.893), (.878), (-.945) is greater than tabulated value of (.878) therefore it shows significant relationship of this independent variable with performance in archery. Whereas, in case of Body force aliment right medial, Body force aliment left medial the obtained values (.360) and (.770) are lower than tabulated value of (.878) therefore it shows insignificant relationship of these independent variable with performance in archery. The significant correlations with height variables suggest that certain aspects of an archer's body positioning, such as the height of the center of mass, center of gravity, and projectile, play a crucial role in archery performance. The negative correlation with the height of the center of mass implies that a lower center of mass is associated with better performance. The insignificant correlations with body forced alignment variables suggest that, at least within the parameters measured, the lateral alignment of the body (right and left medial) does not significantly influence performance in archery. Since the significant relationship was found between Height of body Center of Mass and Height of body Center of Gravity, Height of Projectile and Body force aliment left medial of the subject among independent variables as calculated “r” (-.960), (.887), (-.959) is found greater than the required tabulated value of (.878) at .05 level of significance. In case be seen the significant relationship was found between Height of body Center of Gravity and Body force aliment left medial of the subject among independent variables as calculated “r” (.935), is found greater than the required tabulated value of (.878) at .05 level of significance. The strong correlations among these variables indicate a close relationship between the height-related kinematic variables (center of mass, center of gravity, and projectile) and the lateral alignment of the body (body forced alignment left medial). The negative correlations suggest that as the height of the center of mass decreases, the height of the center of gravity and the height of the projectile tend to decrease, and as the height of the projectile decreases, the body forced alignment left medial tends to increase. The study concludes that there is a statistically significant and positive relationship between the height of the center of gravity and body forced alignment on the left medial side in archery. This finding implies that variations in the height of the center of gravity are associated with corresponding changes in the lateral alignment of the body, specifically towards the left medial side.