Ratio Of Distance Research Articles

Advanced Dynamic Centre of Pressure Diagnostics with Smart Insoles: Comparison of Diabetic and Healthy Persons for Diagnosing Diabetic Peripheral Neuropathy

Although diabetic polyneuropathy (DPN) has a very high prevalence among people with diabetes, gait analysis using cyclograms is very limited, and cyclogram research, in general, is limited to standard measures available in software packages. In this study, cyclograms (movements of the centre of pressure, COP, on and between the plantar surfaces) of diabetics and healthy individuals recorded with a smart insole were compared in terms of geometry and balance index, BI. The latter was calculated as the summed product of standard deviations of cyclogram markers, i.e., start/end points, turning points, and intersection points of the COP. The geometry was assessed by the positions of, and distances between, these points, and the distance ratios (14 parameters in total). The BI of healthy and diabetic individuals differed significantly. Of the fifteen parameters (including the BI), three were suitable as classifiers to predict DPN, namely two distances and their ratio, with false negatives ranging from 1.8 to 12.5%, and false positives ranging from 2.9 to 7.1%. The standard metric of the cyclogram provided by the software packages failed as a classifier. While the BI captures both DPN-related balance and other balance disorders, the changing geometry of the cyclogram in diabetics appears to be DPN-specific.

Effects of Different Spatial Distributions of Vegetation on the Hydraulic Characteristics of Overland Flow

ABSTRACTVegetation plays a crucial role in mitigating and controlling soil erosion caused by overland flow. However, variations in the hydraulic characteristics of overland flow induced by the spatial distribution of vegetation with different row and column spacings are often overlooked in existing literature, potentially leading to significant deviations in predicting these characteristics. In this study, 180 lab‐scale runoff tests were conducted to clarify the hydraulic characteristics of overland flow considering six α (the ratio of the lateral distance of vegetation to stem diameter) levels, six β (the ratio of the slope distance of vegetation to stem diameter) levels, and three slope angles (θ) under five flow discharges (Q) conditions. The results show that the observed flow regime of overland flow belongs to the transition flow regions, shifting from slow to rapid as α and/or β increase. The friction coefficient and the proportion of frictional resistance in the total flow resistance increase with increasing α and β. The local resistance dominates the total flow resistance of bare glass slopes. The local resistance coefficient ξ decreases with increasing α and β, however, it initially increases and then decreases with increasing θ. The impact of β on the local resistance is greater for gentle slopes, whereas the impact of α is more significant for steep slopes. ξ exhibits a negative correlation with Re and the ξ‐Re curves gradually level off as α or β increases, while they become steeper with increasing θ. A prediction model for the total flow resistance was established taking into account the combined effects of Re, α, β and θ, which provides better prediction performance than two other relevant models. The results obtained from this study provide valuable insights into the hydraulic characteristics of overland flow and offer clear guidance for vegetation management in controlling soil erosion on slopes with heterogeneous vegetation coverage.

Enhancing Predicted Visual Acuity After SmartSight Lenticule Extraction: Identifying Key Factors With Machine Learning.

To develop a predictive model aimed at assessing the likelihood of improvement in corrected distance visual acuity (CDVA) for patients undergoing lenticule extraction using the SmartSight system from SCHWIND eye-tech-solutions. This model evaluates the effectiveness and weight of various clinical and procedural parameters in predicting enhancements in visual acuity. Data from 1,262 eyes treated with the SmartSight system, encompassing 86 features, were analyzed. Regression and classification techniques were employed to estimate the probability of CDVA gain, ensuring robust results by comparing different methods. The dataset was divided into training (70%, 883 treatments) and testing (30%, 379 treatments) subsets to ensure comprehensive model evaluation using machine learning methods. Feature significance was determined via analysis of variance and principal components analysis to identify impactful parameters. Three principal components accounting for more than 70% of the data variance were identified. The first component was primarily linked to system settings, whereas the second and third components were associated with patient gender and laterality. Factors significantly influencing CDVA improvement included a higher spot-to-track distance ratio, tighter track distance, lower pulse energy, lower average laser power, larger spot distance, greater cap thickness, and lower dosage. These variables were ranked based on their impact on CDVA enhancement. Using low-energy asymmetric spacing for lenticule extraction with the SmartSight system is safe and effective. This approach improves visual outcomes for patients undergoing treatment for myopic astigmatism, offering a reliable method for predicting CDVA improvements. [J Refract Surg. 2024;40(12):e974-e984.].

A novel analytical technique based on singular integral operators to study EMPS model with two unequal collinear cracks in magneto-electro-elastic solids

A novel analytical technique based on singular integral operators (SIO) is presented to study the strip electric-magnetic polarization saturation (EMPS) model in magneto-electro-elastic (MEE) solids with two unequal collinear cracks. Unknown semipermeable crack-face conditions and saturated zone lengths are evaluated using iterative techniques and the obtained new analytical solutions for dislocation densities. Numerical studies of fracture parameters are conducted with respect to variations in electrical loading, inter crack space distance and crack-length ratio. The accuracy and efficacy of the SIO method are validated against published results for cases with two equal collinear cracks and center crack.

Three‐body confrontation differential game for an aggressive attacker

AbstractIn this work, we study the three‐body confrontation differential game, in which an Attacker attempts to capture a Target while a Defender guards the latter. We decompose the three‐body game into two subgames based on the game of kind theory: the included angle game and the distance ratio game. By integrating the Apollonius circle with these subgames, we define the semipermeable surface and infer the optimal guidance strategies for the three players on this surface. Unlike existing methods, our method effectively addresses the coupling relationship between the target, defender, and attacker, resulting in greater applicability. Based on the derived semipermeable surface, the conditions for the three players to win the game are also presented. These winning conditions are comprehensively considered from both lines of sight, including the angle and the ratio between the Attacker–Target distance and the Attacker–Defender distance, thereby providing a game solution through an analysis of the players' dynamics. From the perspective of viewing angle ratio, our method bridges the gap in the viewing angle game outcomes compared to existing methods. To demonstrate the effectiveness of our method, we provide simulation examples that illustrate the three‐body confrontation game in various scenarios.

Study on Path Planning in Cotton Fields Based on Prior Navigation Information

Aiming at the operation scenario of existing crop coverage and the need for precise row alignment, the sowing prior navigation information of cotton fields in Xinjiang was used as the basis for the study of path planning for subsequent operations to improve the planning quality and operation accuracy. Firstly, the characteristics of typical turnaround methods were analyzed, the turnaround strategy for dividing planning units was proposed, and the horizontal and vertical operation connection methods were put forward. Secondly, the obstacle avoidance strategies were determined according to the traits of obstacles. The circular arc–linear and cubic spline curve obstacle avoidance path generation methods were proposed. Considering the dual attributes of walking and the operation of agricultural machinery, four kinds of operation semantic points were embedded into the path. Finally, path generation software was designed. The simulation and field test results indicated that the operation coverage ratio CR ≥ 98.21% positively correlated with the plot area and the operation distance ratio DR ≥ 86.89% when non-essential reversing and obstacles were ignored. CR and DR were negatively correlated with the number of obstacles when considering obstacles. When considering non-essential reversing, the full coverage of operating rows could be achieved, but DR would be reduced correspondingly.

Osteosynthesis using Scorpion plate for neer type V distal clavicle fracture

BackgroundNeer type V distal clavicle fractures are considered the most unstable fracture type and are characterized by the disruption of continuity between the coracoclavicular (C-C) ligaments and proximal or distal bone fragments. However, owing to the rarity of such fractures, there is currently no universally accepted surgical procedure for their treatment. Recently, the scorpion plate, an anatomical, non-locking, pre-contoured plate with two grasping arms to fix the distal or inferior clavicular fragments, was introduced. This study aimed to investigate the postoperative functional and radiological outcomes of osteosynthesis using only scorpion plates in Neer type V fractures.MethodsWe retrospectively identified 23 patients who underwent scorpion plate fixation for Neer type V fractures at two general hospitals. All patients underwent only plate fixation without C-C ligament augmentation. Subsequently, we investigated their postoperative functional outcomes, complication rates, and modified C-C distance ratio at 1 year.ResultsThe mean postoperative Constant score was 96 ± 5, with all cases achieving bone union. Complications within 1 year postoperatively included plate loosening in one patient (4.3%) and plate irritation in two patients (8.7%). Additionally, the modified C-C distance ratio averaged 114 ± 15%.ConclusionsThis study offers novel insights into the management of Neer type V distal clavicle fractures. Our findings indicate that osteosynthesis using only scorpion plates can lead to satisfactory functional outcomes with minimal complications.

Numerical investigation of hydrodynamic performance and power consumption in stirred reactors with perforated Scaba 6SRGT impellers for non‐Newtonian fluid

AbstractThe present study aims to further understand the effect of perforated Scaba 6SRGT impellers on stirring performance and impeller power consumption by numerically investigating the hydrodynamic properties of non‐Newtonian fluids in a three‐dimensional stirred reactor. After model validation, the fluid velocity, stagnant region dimensionless volume, and impeller power consumption are quantitatively analyzed under the conditions of influencing parameters, including blade perforation pitch, ratio of distance between adjacent perforations, and perforation arrangement. The results reveal that the range of distribution of acceleration and peak velocity of the fluid along the radial appear in regions lower and larger than the dimensionless radius of the impeller (|r/R| = 0.45), respectively. Increasing the perforation pitch from 14 to 20 mm increases fluid velocity from 0.284 to 0.305 m/s and power consumption from 26.99 to 27.25 W, while reducing the stagnant region volume from 16.76% to 14.71%. The fluid velocity and impeller power consumption slightly increase with the ratio of distance between adjacent perforations. Circular‐shaped middle perforations yield higher fluid velocities and vorticity compared to lozenge‐shaped ones. The highest and lowest power consumptions are obtained by circular–circular–circular and lozenge–lozenge–lozenge perforation shape arrangements with values of 27.25 and 26.9 W, respectively.

Reducing low-frequency noise radiation from a concrete box girder bridge using acoustic short circuits

Low-frequency noise (20–200 Hz) radiated from concrete box girder bridges on urban viaduct railway lines is a significant source of disturbance to nearby residents. Many researchers have investigated methods which can be used to effectively reduce this bridge noise. Currently, most of the methods are based on the principles of vibration isolation and/or absorption. This paper, after modelling and analysing the contributions of various parts of a concrete box girder bridge to the total noise radiated from the bridge, presents a study on the potential in bridge noise control of making holes to create acoustic short circuits on the bridge wings. It is found that by this means the bridge noise can be reduced by up to 6.8 dB at standard-specified measurement points. Additionally, a 3dB-effectiveness distance ratio design method for acoustic short-circuiting is proposed, which effectively reduces bridge noise and achieves stable noise reduction outcomes.

Construct Validity of a Wearable Inertial Measurement Unit (IMU) in Measuring Postural Sway and the Effect of Visual Deprivation in Healthy Older Adults.

Inertial Motor sensors (IMUs) are valid instruments for measuring postural sway but their ability to detect changes derived from visual deprivation in healthy older adults requires further investigations. We examined the validity and relationship of IMU sensor-derived postural sway measures compared to force plates for different eye conditions in healthy older adults (32 females, 33 males). We compared the relationship of the center of mass and center of pressure (CoM and CoP)-derived total length, root means square (RMS) distance, mean velocity, and 95% confidence interval ellipse area (95% CI ellipse area). In addition, we examined the relationship of the IMU sensor in discriminating between open- (EO) and closed-eye (EC) conditions compared to the force plate. A significant effect of the instruments and eye conditions was found for almost all the variables. Overall, EO and EC variables within (force plate r, from 0.38 to 0.78; IMU sensor r, from 0.36 to 0.69) as well as between (r from 0.50 to 0.88) instruments were moderately to strongly correlated. The EC:EO ratios of RMS distance and 95% CI ellipse area were not different between instruments, while there were significant differences between total length (p = 0.973) and mean velocity (p = 0.703). The ratios' correlation coefficients between instruments ranged from moderate (r = 0.65) to strong (r = 0.87). The IMU sensor offers an affordable, valid alternative to a force plate for objective, postural sway assessment.

Prediction of Fractures After Open Wedge High Tibial Osteotomy Based on the Distance From the Tibial Osteotomy Point to the Medial Edge of the Tibia

ObjectiveTo investigate the relationship between the distance from the medial tibial osteotomy point to the medial tibial edge and the development of lateral tibial hinge fracture (type II) and intra-articular tibial plateau fracture (type III) in patients who have degenerative disease undergoing open wedge high tibial osteotomy (OWHTO). This information will aid surgeons in avoiding the occurrence of fractures. MethodsThis retrospective study analyzed 304 patients who underwent OWHTO from January 2018 to January 2024 in the Affiliated Hospital of Qingdao University. The distance from the tibial osteotomy point to the medial tibial edge on imaging was analyzed to determine its association with fracture. A one-way analysis of variance was used to compare the differences in height, weight, body mass index (BMI), the distance from the medial tibial osteotomy point to the medial tibial edge, sex, left and right sides of the knee, and osteoporosis in the occurrence of type II and type III fractures. Receiver operating characteristic curves were used to identify the critical distances associated with type II and type III fractures. Logistic regression analysis was used to obtain the odds ratio (OR) of the critical distance adjusted for age, sex, left and right sides, BMI, and T value. ResultsThere were 40 fractures (13.3%) in 304 patients after OWHTO, comprising 21 type II fractures (7.0%) and 19 type III fractures (6.3%). A single-factor variance analysis showed that the tibial bone cutting distance to the medial tibial edge (P = 0.02) and osteoporosis (P = 0.01) were significantly different from the fracture. Receiver operating characteristic curves showed that the critical distances for type II and type III fractures were 40.5 and 47.1 mm, respectively. Logistic regression analysis showed that the ORs of type II and type III fractures were 1.061 (95% CI [confidence interval] = 1.010 to 1.115) and 1.064 (95% CI = 1.011 to 1.119), respectively. ConclusionIn patients undergoing OWHTO, the risk factors for type II and III fractures are osteoporosis and the distance from the tibial bone cutting point to the medial tibial edge. This distance should be minimized during OWHTO to avoid type II and III fractures.

Auto-contouring of cardiac substructures for Stereotactic arrhythmia radioablation (STAR): A STOPSTORM.eu consortium study

Background/PurposeHigh doses to healthy cardiac substructures (CS) in stereotactic arrhythmia radioablation (STAR) raise concerns regarding potential treatment-induced cardio-toxicity. However, CS contours are not routinely created, hindering the understanding of the CS dose–effect relationships. To address this issue, the alignment of CS contouring was initiated within the STOPSTORM consortium. In this study, we developed and evaluated auto-contouring models trained to delineate CS and major vessels in ventricular tachycardia (VT) patients. MethodsEight centres provided standard treatment planning computed tomography (CT) and/or contrast-enhanced CT datasets of 55 VT patients, each including 16 CS. Auto-contouring models were trained to contour either large structures or small structures. Dice Similarity Coefficient (DSC), 95 % Hausdorff distance (HD95) and volume ratio (VR) were used to evaluate model performance versus inter-observer variation (IOV) on seven VT patient test cases. Significant differences were tested using the Mann-Whitney U test. ResultsThe performance on the four chambers and the major vessels (median DSC: 0.88; HD95: 5.8–19.4 mm; VR: 1.09) was similar to the IOV (median DSC: 0.89; HD95: 4.8–14.0 mm; VR: 1.20).For the valves, model performance (median DSC: 0.37; HD95: 11.6 mm; VR: 1.63) was similar to the IOV (median DSC: 0.41; HD95: 12.4 mm; VR: 3.42), but slightly worse for the coronary arteries (median DSC: 0.33 vs 0.42; HD95: 24.4 mm vs 16.9 mm; VR: 1.93 vs 3.30). The IOV for these small structures remains large despite using contouring guidelines. ConclusionCS auto-contouring models trained on VT patient data perform similarly to IOV. This allows for time-efficient evaluation of CS as possible organs-at-risk.

Prevalence of masked hypertension in children with chronic kidney disease: a cross-sectional study.

Hypertension poses a significant risk as a complication of chronic kidney disease (CKD), contributing to its hastened advancement. Implementing ambulatory blood pressure monitoring (ABPM), a straightforward and non-invasive method proves beneficial in identifying masked hypertension. A cross-sectional study was carried out involving children aged 5-15years diagnosed with CKD to estimate the difference in masked HTN prevalence between the 2014 and 2022 AHA ABPM guidelines. The study encompassed a comprehensive assessment, including 24-h blood pressure monitoring and was performed using ABPM. Left ventricular mass (LVM) was computed based on measurements obtained from M-mode echocardiography. PWV was determined by calculating the ratio of distance (D) to time (t). We examined a cohort of 138 children diagnosed with CKD. Our findings reveal that, in accordance with the 2022 American Heart Association (AHA) ABPM guidelines, prevalence of masked hypertension stands at 29.7% marking a notable increase of 17.4% compared to the 2014 ABPM guidelines signifying a substantial proportion of undetected hypertensive cases. Furthermore, the prevalence of hypertension is 48.5% as detected by ABPM, marking a notable increase of 22.5%. A substantial occurrence of masked hypertension was identified in pediatric CKD patients through the application of ABPM. ABPM proves to be an effective tool for uncovering masked hypertension in children with CKD.

Joint jammer selection and power optimization in covert communications against a warden with uncertain locations

In covert communications, joint jammer selection and power optimization are important to improve performance. However, existing schemes usually assume a warden with a known location and perfect channel state information (CSI), which is difficult to achieve in practice. To be more practical, it is important to investigate covert communications against a warden with uncertain locations and imperfect CSI, which makes it difficult for legitimate transceivers to estimate the detection probability of the warden. First, the uncertainty caused by the unknown warden location must be removed, and the optimal detection position (OPTDP) of the warden is derived which can provide the best detection performance (i.e., the worst case for a covert communication). Then, to further avoid the impractical assumption of perfect CSI, the covert throughput is maximized using only the channel distribution information. Given this OPTDP based worst case for covert communications, the jammer selection, the jamming power, the transmission power, and the transmission rate are jointly optimized to maximize the covert throughput (OPTDP-JP). To solve this coupling problem, a heuristic algorithm based on maximum distance ratio (H-MAXDR) is proposed to provide a sub-optimal solution. First, according to the analysis of the covert throughput, the node with the maximum distance ratio (i.e., the ratio of the distances from the jammer to the receiver and that to the warden) is selected as the friendly jammer (MAXDR). Then, the optimal transmission and jamming power can be derived, followed by the optimal transmission rate obtained via the bisection method. In numerical and simulation results, it is shown that although the location of the warden is unknown, by assuming the OPTDP of the warden, the proposed OPTDP-JP can always satisfy the covertness constraint. In addition, with an uncertain warden and imperfect CSI, the covert throughput provided by OPTDP-JP is 80% higher than the existing schemes when the covertness constraint is 0.9, showing the effectiveness of OPTDP-JP.

Comparison of Upper Lip Bite Test and Thyromental Distance with Other Airway (Malampatti and Inter Incisor Distance) Assessment Tests for Predicting Difficult Endotracheal Intubation

Objective: To study the ability of upper lip bite test and thyromental distance to predict difficult endotracheal intubation when compared to standard assessment tests such as Mallampati and inter incisor distance. Study Design: Cross-sectional validation study. Place and Duration of Study: Department of Anesthesiology, Pak-Emirates Military Hospital, Rawalpindi, Pakistan, Sep 2020 to Mar 2021. Methodology: We studied a total of 50 patients who reported for the administration of general anesthesia. All patients underwent evaluation with modified Mallampati test, upper lip bite test and thyromental distance test. All participants underwent subsequent intubation according to a standard protocol. The researcher documented difficult intubations. Results: We found the upper lip bite test to have a sensitivity of 75.7%, a specificity of 84.2%, and a diagnostic accuracy of 78.6%. Thyromental distance had a sensitivity, specificity, and diagnostic accuracy of 51.4%, 78.9% and 60.7%, respectively while the modified Mallampati had a sensitivity of 64.9%, 89.5%, specificity and a diagnostic accuracy of 73.2%. Conclusion: Upper lip bite test is a useful bedside assessment tool with which to predict the probability of a difficult endotracheal intubation. Height to thyromental distance ratio test is also acceptable for rapid assessment.

Study on the Mechanical Behavior of Top-Chord-Free Vierendeel-Truss Composite Slabs

A top-chord-free Vierendeel-truss composite slab (TVCS) comprises a concrete slab, several vertical webs, and a steel bottom chord. In this study, static tests and finite element analyses were conducted based on an actual project to investigate the deformation, crack characteristics, ultimate bearing capacity, and failure mode of the composite slab. The findings indicated that the loading process of this type of floor can be divided into elastic, elastoplastic, and failure stages. The section stress distribution in the elastic stage was further analyzed. The crack development pattern exhibited a fine density in the pure bending sections of the concrete slabs, while demonstrating good overall flexural bearing capacity and ductility for the composite slab. Experimental results were compared with the ANSYS finite element model simulation to validate the accuracy of the simulation. Parametric analysis was conducted to assess the impact of concrete strength, steel strength, vertical web width, and distance ratios on the mechanical characteristics of the composite slab. By introducing an adjustment coefficient for the vertical web distance ratio, a revised calculation formula for flexural bearing capacity was proposed, which aligned well with the finite element analysis.

Study evaluating the curling property of weft knitted fabrics based on pixel analysis

Curling is a common phenomenon observed in knitted fabrics. Curling poses many problems for fabric and clothing production, especially for digital devices, where it can affect the production quality and efficiency, while there is still no accurate method for evaluating it. This study established an evaluation method for the curling properties of knitted fabrics based on pixel statistics. Weft knitted fabric samples were created using a fabric cutter and a piece of paper was placed underneath the fabric. The fabric sample curls, whereas the paper represents a non-curling state. Subsequently, a scanner was used to scan the projections of the circular samples and paper to obtain digital images. The pixel amounts of the curled fabric and paper digital images were measured using the Photoshop 2020 software. The ratio between the fabric and paper projection pixels can be calculated by subtracting from 100% and converting the curling area ratio to the curling distance ratio. This can be used to represent the curling properties of knitted fabrics. The error between the theoretical and measured values is <0.1%, indicating a high level of accuracy. Ten knitted fabrics were validated for analysis. The sample with the maximum deviation between the left, middle, and right positions was 5.9%, whereas that with the minimum deviation was 0.3%. Subsequently, the fabrics were retested on the 7th and 14th days to assess reproducibility. The maximum deviation for each fabric on the 1st, 7th, and 14th days was 4.1%, and the minimum deviation was 0%. Therefore, it can be concluded that the method described in this study can accurately quantify the curling properties of knitted fabrics.

Development of craquelure patterns in paintings on canvas

Canvas paintings are layered structures composed of canvas support sized with animal glue, a preparatory layer of the ground, and paint and varnish layers on the top. Preventing or limiting humidity-induced stresses in these structures requires an understanding of the relevant processes and risks. A three-dimensional model of a canvas painting was used to analyse stresses and crack development in the two-layer structure comprised of a glue-sized canvas on a wooden stretcher with a layer of stiff chalk-glue ground representing a pictorial layer in historic canvas paintings. The model was subjected to a large relative humidity fall which induced shrinkage of the glue-sized canvas. The modelling revealed that when a stretcher with flexible wooden bars is considered, high tensile stresses arise in the ground layer at the corners of the painting, and cracks are formed in these areas in the direction perpendicular to the painting’s diagonal. Ratios of critical distances between cracks to the ground layer thickness for which stresses in the midpoints between the cracks dropped to below the level inducing fracture in the material were estimated for various magnitudes of the relative humidity drop and thicknesses of the ground layer. Increasing ground layer thickness limits the hygric response of the sized canvas and makes the paintings less vulnerable to humidity variations. The ratio of stress along the diagonal calculated for painting with one crack to the solution without cracks was described by the double Lorentz function. A simple procedure of calculating stress variations along the diagonal—using the function—on a sequential addition of cracks was developed. Cracks in central parts of canvas painting were found to be induced by permanent cumulative drying shrinkage of the oil-based paints and grounds due to the evolution of the molecular composition of the oil binder. The outcome of the modelling indicated that the risk of cracking of the pictorial layers in canvas paintings due to drops in ambient relative humidity was small.

Micromechanism of interparticle normal magnetic attraction effect in magnetorheological suspensions based on magnetic-dipole theory

In order to reveal adsorption-regulation micromechanism and debonding micromechanism between wall surface and magnetorheological (MR) wall-climbing robot legs, an interparticle normal magnetic attraction (NMA) mechanics model was constructed based upon the magnetic-dipole theory. According to analysis of NMA mechanics, it was confirmed that the interparticle NMA could be intensified with enhancing magnetic-particle diameter but was weakened with ratio of adjacent magnetic-particles distance to magnetic-particle radius. It means that the adhesive capacity between MR wall-climbing robot legs and wall surface could be strengthened by increasing magnetic-particle size and decreasing interparticle distance. Furthermore, it was found that the NMA of the first particle in the magnetic chain was positively related to magnetic-particles number until the magnetic-particles number reached a critical value. Consequently, the adsorption ability between MR wall-climbing robot legs and wall surface could be effectively controlled by changing magnetic-particles number. Besides, the strongest NMA appeared at the middle of the magnetic chain. However, the weakest NMA locates at both ends of the magnetic chain. Thus, it could be concluded that the end of the magnetic chain would be separated from wall surface rather than fracture occurred in the middle of the magnetic chain when the MR wall-climbing robot legs divorced from wall surface.

A Non-Contacted Height Measurement Method in Two-Dimensional Space.

Height is an important health parameter employed across domains, including healthcare, aesthetics, and athletics. Numerous non-contact methods for height measurement exist; however, most are limited to assessing height in an upright posture. This study presents a non-contact approach for measuring human height in 2D space across different postures. The proposed method utilizes computer vision techniques, specifically the MediaPipe library and the YOLOv8 model, to analyze images captured with a smartphone camera. The MediaPipe library identifies and marks joint points on the human body, while the YOLOv8 model facilitates the localization of these points. To determine the actual height of an individual, a multivariate linear regression model was trained using the ratios of distances between the identified joint points. Data from 166 subjects across four distinct postures: standing upright, rotated 45 degrees, rotated 90 degrees, and kneeling were used to train and validate the model. Results indicate that the proposed method yields height measurements with a minimal error margin of approximately 1.2%. Future research will extend this approach to accommodate additional positions, such as lying down, cross-legged, and bent-legged. Furthermore, the method will be improved to account for various distances and angles of capture, thereby enhancing the flexibility and accuracy of height measurement in diverse contexts.