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A Study on the Preliminary Validity Analysis of Korean Firefighter Job-Related Physical Fitness Test
The purpose of this study is to revise and modify the firefighter job-related performance tests from overseas to implement into the circumstances in Korea, examine its validity by analyzing the level of association between the test employed in the ongoing firefighter selection process, and propose a Korean firefighter job-related physical fitness test. Therefore, a modified version of Candidate Physical Ability Test (CPAT) from the United States firefighter selection process was conducted on 28 male firefighter officer candidates. Recorded results from VO2max, heart rate, blood lactate, anaerobic power test, and the ongoing Korean firefighter physical fitness test were analyzed to assess the validity of the modified test. IBM SPSS Statistics Ver. 27.0 was employed for the data correlation analysis in different fitness factors and the total circuit physical test time. The results revealed the proposed modified firefighter job-related physical fitness test showed significant correlation with VO2max (r = −0.450, p < 0.05), METS (r = −0.735, p < 0.01) recovery lactate over 15 min (r = −0.460, p < 0.05), peak power (r = −0.484, p < 0.05), average power (r = −0.647, p < 0.01), and in the ongoing firefighter physical fitness test, grip strength (r = −0.709, p < 0.01), lower back strength (r = −0.681, p < 0.01), standing long jump (r = −0.618, p < 0.01), sit-ups (r = −0.397, p < 0.05), and shuttle run (r = −0.523, p < 0.01). Fitness factors including VO2max, recovery lactate, anaerobic power, muscular strength, and so forth known to play a crucial role in firefighting operations were also shown to be important in the modified firefighter job-related physical fitness test. However, we suggest that studies with a larger sample size are needed in order to generalize our findings.
Journal Article
Physical activity assessment : a lifecourse approach
\"The book provides readers with a thorough grounding in physical activity assessment from a lifecourse perspective and assesses current methods of measurement, including comparison studies, criterion methods, subjective assessment methods and physical activity monitors. It then goes on to offer guidance on the optimal measurement techniques of physical activity across the lifecourse, suggesting how data should be collected, analysed and quantified in light of modern technology and global connectivity, and what these methods mean for physical activity guidelines and interventions, and public health outcomes\"-- Provided by publisher.
Book
Investigating the preparation and characterization of nano-clay modified asphalts
In order to extend the lifespan of flexible pavements materials, a binder quality requests to be modified. The aim of the present research is to assess the physical features of original and modified asphalts with nanoclay materials. These features including; softening point values, penetration grades, viscosity values, penetration index values, and ductility. Three percentages of nanoclay contents (3, 5, and 7) % by of the asphalt weight were blended by a shear blender set at (4000) rpm., and mixing time set about 45 min. at 140 °C. Physical tests results showed that adding nanoclay material as a modifier was beneficial in enhancing the asphalts features. For example, viscosity values and softening point values increase when increase in the nanoclay content. Consequently, the mixing temperatures and compaction temperatures of the modified asphalts increase with increase the nanoclay content to reach (170 °C). While the penetration and ductility values decrease when increase the modifier content. Regarding the penetration index of the modified asphalts, it is enhanced by increase in the nanoclay proportions. Hence, the modified asphalt with 7% of nanoclay produces the greater value of penetration index accordingly, it has a positive influence on the rutting resistance.
Journal Article
A Differential Evolutionary-Based XGBoost for Solving Classification of Physical Fitness Test Data of College Students
The physical health of college students is an important basis for societal development, which directly impacts the competitiveness of future talents and the overall vitality of the nation. To accurately and timely identify the physical health status of college students, a hybrid model of DE-XGBoost is proposed in this study: a discrete coding strategy is designed to solve the XGBoost hyperparameter optimization problem, and differential evolution (DE) is used to achieve global parameter optimization. Based on 20,452 physical test records of a university in 2022, the empirical comparison shows that the accuracy rate, recall rate, and F1 value of the model are improved by 3.5–7.9% compared with support vector machine (SVM), gradient boosting machine (GBM), and multi-layer perceptron (MLP), showing significant performance advantages. This research provides a novel and efficient framework for physical fitness classification, with potential applications in educational curriculum design.
Journal Article
Evaluating an operator physical fitness test prototype for tactical air control party and air liaison officers : a preliminary analysis of test implications
\"The U.S. Air Force asked the RAND Corporation to assist its development and validation of gender-neutral tests and standards for battlefield airmen (BA) specialties. The Air Force has conducted an extensive validation study of occupational relevance of physical fitness tests and standards. Following the fitness test validation study, one enlisted specialty (Tactical Air Control Party [TACP]) and one officer BA specialty (Air Liaison Officer [ALO]) moved forward with an implementation plan to further evaluate a set of recommended tests and continuation standards. This report describes RAND's assistance to the Air Force on two fronts: (1) conducting a preliminary evaluation of potential issues and concerns that might influence implementation effectiveness and (2) developing a framework for evaluating the implementation of occupationally relevant and specific tests and standards. This work provides the foundation for ongoing review and evaluation of Air Force fitness tests and standards, which are designed to ensure that airmen are capable of performing critical physical tasks associated with their assigned specialties\"--RAND website.
Book
Finite Element Method Simulations and Experiments of Detachments of Lycium barbarum L
When harvesting Lycium barbarum L., excess amounts of detachments of the half-ripe fruit, unripe fruit, flowers, and leaves significantly affect the yield and adversely affect the subsequent processing, such as drying and grading. Finite element method (FEM) simulations and experiments of detachments were performed to harvest more ripe fruit and less half-ripe fruit, unripe fruit, flowers, and leaves. Three-dimensional (3D) models of the ripe fruit, half-ripe fruit, unripe fruit, flowers, leaves, fruit calyxes (flower calyx), fruit stems (flower stem), and branches were constructed using a 3D scanner, and material mechanics models of the above parts were established based on physical tests with universal testing machines. Detachment simulations and experiments of the ripe fruit, half-ripe fruit, unripe fruit, flowers, and leaves were performed to determine the detachment mechanisms and sequences. The detachment forces of each set of two parts were obtained. The field experiments showed that the detachment force between the fruit and calyx of ripe fruit was the lowest value of these forces, and only the ripe fruit was the first to detach from the calyx when harvesting. The results provided data support on the mechanics properties of wood and the optimization basis for the harvesting method of L. barbarum.
Journal Article
Three-Dimensional Physical Test Study on the Overburden Breaking Behavior of Non-Penetrating Pre-Splitting in Small-Coal-Pillar Roadway Roofs
In longwall coal mining, significant deformation of small-pillar roadways presents challenges for the safe and efficient retreat of mining panels. Non-penetrating directional pre-splitting alters the roof structure of these roadways and effectively manages their stability under high stress during mining operations. In this study, a three-dimensional experimental model for the non-penetrating pre-splitting of small-coal-pillar roadway roofs was established, the apparent resistivity change in the rock layer during mining of the working face was determined, the propagation law of high-frequency electromagnetic waves in the overlying rock was studied, and the stress distribution law of the surrounding rock was investigated. After non-penetrating pre-splitting in the roof, the apparent resistivity change rate of the overlying rock increased and the electromagnetic waveform exhibited scattering and diffraction, forming a short cantilever beam. After mining, the stress in the adjacent mining panel gateway reduced, resulting in a pressure relief effect on the surrounding rock. These findings were further validated through field application, where the overall deformation of the roadway was reduced by 57%. The research results shed light on the management of roof control in small-coal-pillar roadways and the rational determination of non-penetrating pre-splitting parameters.
Journal Article
Numerical Analysis and Experiments on Heavy Oil Heating of Shipwrecks
Analyze the change of oil temperature flow times during the heating process of wreck heavy oil and the temperature gradient change in the radiation area of the heating source. Using the result guide the heating process of low-temperature underwater oil recovery operations on the wreck. fluid software was used for the analysis process of the numerical simulation, and the physical model test is a simulation test of low temperature underwater electromagnetic heating of heavy oil. In this way, data related to the heating process of heavy oil can be obtained. from the numerical analysis results and the physical model test results, it can be concluded that the numerical simulation results are similar to the experimental verification results. The result can be used for engineering guidance. Due to the physical properties of heavy oil, the oil temperature decays faster during the heating process and the radiation effect of heat source is small, using the electromagnetic heater heats the heavy oil in the oil tank, and the heavy oil can be heated to meet the requirements of the pumping operation in a short time. The calculation model parameters are derived from actual operations. Numerical calculations and physical test results are of great significance to engineering guidance and can guide the underwater cryogenic oil pumping operation of shipwrecks.
Journal Article