Joint Coordinates Research Articles

A skeleton-based method for exercise recognition based on 3D coordinates of human joints

<p>The aim of the work is to develop the method of identification and comparison of poses and exercises performed by a person that will have a low sensitivity to data errors. This method uses their formal descriptions in the form of conjunctions of logical statements and should work regardless of the shooting angle at which the video was taken and the proportions of the person on it. Each statement describes the position of the joints relative to each other along one of the axes. The joint coordinates are corrected by taking into account the length of the bones that connect them that eliminates the necessity to process outliers and it also improves the accuracy of joints positioning. Removal of errors out of the data using the method of averaging the graph along each axis at every step. In order to do this, consecutive points are grouped so that the difference between the maximum and the minimum does not exceed the error. The groups are then filtered to leave only those in which both are smaller or both are larger. The proposed method of identification requires just a modern smartphone and has no restrictions on how to take video of exercises.</p>

Friction-induced nonlinear dynamics in a spline-rotor system: Numerical and experimental studies

Excessive vibrations induced by intrinsic internal friction in spline joints critically impact the reliability and safety of high-speed rotating machinery. To address this concern, this paper presents experimental and numerical research on a flexible rotor system subjected to frictional contact within the spline joint. Experiments are conducted on a scaled rotor test rig designed to emulate the tail rotor drive shaft of helicopters, aiming to explore vibration behaviors under various operating conditions. A reduced-order mathematical model based on the test rig, considering the multi-interface friction of the spline joint and deformation coordination with a flexible coupling, is formulated. The numerical study, which incorporates both stability analysis and transient nonlinear dynamics, is then presented to quantitatively evaluate the occurrence conditions and excitation mechanisms leading to friction-induced instabilities. A parameter study is further conducted to elucidate the roles of various parameters in shaping self-excited vibration behaviors. The results reveal that the cross-coupling of frictional forces within the spline joint acts as the driving force of instabilities at supercritical speeds, with the resulting self-excited responses dominated by the frequency of the first critical speed. The study also highlights the necessity of integrating experimental and numerical analysis to better predict and understand the self-excited vibration phenomena in the spline-shaft systems.

Lower-extremity inter-joint coordination variability in active individuals with transtibial amputation and healthy males during gait.

This study was aimed to compare the variability of inter-joint coordination in the lower-extremities during gait between active individuals with transtibial amputation (TTAs) and healthy individuals (HIs). Fifteen active male TTAs (age: 40.6±16.24years, height: 1.74±0.09m, and mass: 71.2 ± 8.87kg) and HIs (age: 37.25±13.11years, height: 1.75±0.06m, and mass: 74 ± 8.75kg) without gait disabilities voluntarily participated in the study. Participants walked along a level walkway covered with Vicon motion capture system, and their lower-extremity kinematics data were recorded during gait. The spatiotemporal gait parameters, lower-extremity joint range of motion (ROM), and their coordination and variability were calculated and averaged to report a single value for each parameter based on biomechanical symmetry assumption in the lower limbs of HIs. Additionally, these parameters were separately calculated and reported for the intact limb (IL) and the prosthesis limb (PL) in TTAs individuals. Finally, a comparison was made between the averaged values in HIs and those in the IL and PL of TTAs subjects. The results showed that the IL had a significantly lower stride length than that of the PL and averaged value in HIs, and the IL had a significantly lower knee ROM and greater stance-phase duration than that of HIs. Moreover, TTAs showed different coordination patterns in pelvis-to-hip, hip-to-knee, and hip-to-ankle couplings in some parts of the gait cycle. It concludes that the active TTAs with PLs walked with more flexion of the knee and hip, which may indicate a progressive walking strategy and the differences in coordination patterns suggest active TTA individuals used different neuromuscular control strategies to adapt to their amputation. Researchers can extend this work by investigating variations in these parameters across diverse patient populations, including different amputation etiologies and prosthetic designs. Moreover, Clinicians can use the findings to tailor rehabilitation programs for TTAs, emphasizing joint flexibility and coordination.

Lower extremity joint angle, moment, and coordination throughout a double limb drop vertical jump in individuals with anterior cruciate ligament reconstruction

ABSTRACT Individuals with anterior cruciate ligament reconstruction (ACLR) utilise different landing biomechanics between limbs, but previous analyses have not considered the continuous or simultaneous joint motion that occurs during landing and propulsion. The purpose of this study was to compare sagittal plane ankle/knee and knee/hip coordination patterns as well as ankle, knee, and hip angles and moments and vertical ground reaction force (vGRF) between the ACLR and uninjured limbs during landing and propulsion. Fifteen females and thirteen males performed a drop vertical jump from a 30 cm box placed half their height from force platforms. Coordination was compared using a modified vector coding technique and binning analysis. Kinematics and kinetics were time normalised for waveform analyses. Coordination was not different between limbs. The ACLR limb had smaller dorsiflexion angles from 11 to 16% of landing and 24 to 75% of landing and propulsion, knee flexion moments from 5 to 15% of landing, 20 to 31% of landing, and 35 to 91% of landing and propulsion, and vGRF from 92 to 94% of propulsion compared with the uninjured limb. The ACLR limb exhibited smaller dorsiflexion angles to potentially reduce the knee joint moment arm and mitigate the eccentric and concentric demands on the ACLR knee during landing and propulsion, respectively.

Parent-child sensorimotor coordination in toddlers with and without hearing loss.

Infants experience the world through their actions with objects and their interactions with other people, especially their parents. Prior research has shown that school-age children with hearing loss experience poorer quality interactions with typically hearing parents, yet little is known about parent-child interactions between toddlers with hearing loss and their parents early in life. In the current study, we used mobile eye-tracking to investigate parent-child interactions in toddlers with and without hearing loss (mean ages: 19.42 months, SD = 3.41 months). Parents and toddlers engaged in a goal-directed, interactive task that involved inserting coins into a slot and required joint coordination between the parent and the child. Overall, findings revealed that deaf toddlers demonstrate typical action skills in line with their hearing peers and engage in similar interactions with their parents during social interactions. Findings also revealed that deaf toddlers explored objects more and showed more temporal stability in their motor movements (i.e. less variation in their timing across trials) than hearing peers, suggesting further adaptability of the deaf group to their atypical sensory environment rather than poorer coordination. In contrast to previous research, findings suggest an intact ability of deaf toddlers to coordinate their actions with their parents and highlight the adaptability within dyads who have atypical sensory experiences.

Workout Classification Using a Convolutional Neural Network in Ensemble Learning.

To meet the increased demand for home workouts owing to the COVID-19 pandemic, this study proposes a new approach to real-time exercise posture classification based on the convolutional neural network (CNN) in an ensemble learning system. By utilizing MediaPipe, the proposed system extracts the joint coordinates and angles of the human body, which the CNN uses to learn the complex patterns of various exercises. Additionally, this new approach enhances classification performance by combining predictions from multiple image frames using an ensemble learning method. Infinity AI's Fitness Basic Dataset is employed for validation, and the experiments demonstrate high accuracy in classifying exercises such as arm raises, squats, and overhead presses. The proposed model demonstrated its ability to effectively classify exercise postures in real time, achieving high rates in accuracy (92.12%), precision (91.62%), recall (91.64%), and F1 score (91.58%). This indicates its potential application in personalized fitness recommendations and physical therapy services, showcasing the possibility for beneficial use in these fields.

RGB 이미지 기반 인간 동작 추정을 통한 투구 동작 분석

Pitching is a major part of baseball, so much so that it can be said to be the beginning of baseball. Analysis of accurate pitching motions is very important in terms of performance improvement and injury prevention. When analyzing the correct pitching motion, the currently used motion capture method has several critical environmental drawbacks. In this paper, we propose analysis of pitching motion using the RGB-based Human Pose Estimation (HPE) model to replace motion capture, which has these shortcomings, and use motion capture data and HPE data to verify its reliability. The similarity of the two data was verified by comparing joint coordinates using the Dynamic Time Warping (DTW) algorithm.

PEMBENTUKAN DAN PELATIHAN KADEK SAJIKU (SEHAT JIWAKU) SEBAGAI UPAYA MEWUJUDUKAN DESA SIAGA SIEHAT JIWA MASYARAKAT TELUK TOMINI

The Mental Health Alert Village (DSSJ) is a community-based mental health program service model formed from the alert village's development. A form of community empowerment through a community-based mental health service approach, namely the formation and training of mental health cadres. Cadres play a role in identifying risk groups through data collection, early detection, providing health education, motivating patients and families and conducting program outreach to the community. This Thematic KKN service aims to empower the community by forming and training serving (healthy my soul) cadres. The methods include training, lectures, questions and answers, discussions and practice. This program is in collaboration with the Tabongo Village Government, Dulupi. Implementation of activities at the preparation stage emphasizes the preparation of teams and partners through joint coordination meetings regarding the need for implementing actions. This activity was part of my mental health care training (SAJIKU). Community participation in training for enthusiastic cadres was targeted at 80% of those invited to attend; in reality, 100% followed. There was an increase ine-ISSN : 2715-9558 p-ISSN : 2716-0912 Volume 6 Issue 153Jurnal Pengabdian Kepada Masyarakat Ungu (ABDI KE UNGU)knowledge from pre and post-scores; the average pre-test score was 50 to 82 for the average post-test score. Cadres are expected to continue to practice learning about mental health by continuing to carry out mental health care activities and providing education to the community.

International Instruments for the Principle of Equality

The purpose of this paper is to show what are the international instruments for the realization of equality and non-discrimination. The international instruments for the realization of equality and to fight discrimination are always in continuous development, being harmonized with the initiatives of different countries. These initiatives not only individually but also in joint coordination. The concept of equality and freedom has evolved enormously in the last decades, but it still remains a present problem. The aim is that these principles are not only foreseen in international conventions or other legal acts, but to be realized in practice. The main objectives of the paper are: 1. To give a broader picture of all international instruments for the realization of equality, 2. To show what measures are taken to realize the principle of equality. Methodology: for the realization of the paper, I have based the collection of information from secondary sources, such as various authors who have spoken about equality and the most important international instruments that sanction the principle of equality. Qualitative methods have been used and the collected information will be analyzed, drawing the relevant recommendations and conclusions. First, what equality is will be determined, then continuing with the interpretation of international acts for the realization of equality and protection from discrimination. Received: 25 December 2023 / Accepted: 25 February 2024 / Published: 23 April 2024

Automatic detection of foot-strike onsets in a rhythmic forelimb movement

Rhythmic movement is the fundamental motion dynamics characterized by repetitive patterns. Precisely defining onsets in rhythmic movement is essential for a comprehensive analysis of motor functions. Our study introduces an automated method for detecting rat's forelimb foot-strike onsets using deep learning tools. This method demonstrates high accuracy of onset detection by combining two techniques using joint coordinates and behavioral confidence scale. The analysis extends to neural oscillatory responses in the rat's somatosensory cortex, validating the effectiveness of our combined approach. Our technique streamlines experimentation, demanding only a camera and GPU-accelerated computer. This approach is applicable across various contexts and promotes our understanding of brain functions during rhythmic movements.

A Performance Comparison of Japanese Sign Language Recognition with ViT and CNN Using Angular Features

In recent years, developments in deep learning technology have driven significant advancements in research aimed at facilitating communication with individuals who have hearing impairments. The focus has been on enhancing automatic recognition and translation systems for sign language. This study proposes a novel approach using a vision transformer (ViT) for recognizing Japanese Sign Language. Our method employs a pose estimation library, MediaPipe, to extract the positional coordinates of each finger joint within video frames and generate one-dimensional angular feature data from these coordinates. Then, the code arranges these feature data in a temporal sequence to form a two-dimensional input vector for the ViT model. To determine the optimal configuration, this study evaluated recognition accuracy by manipulating the number of encoder layers within the ViT model and compared against traditional convolutional neural network (CNN) models to evaluate its effectiveness. The experimental results showed 99.7% accuracy for the method using the ViT model and 99.3% for the results using the CNN. We demonstrated the efficacy of our approach through real-time recognition experiments using Japanese sign language videos.

SYSTEM OF STATE REGULATION OF PROFESSIONAL TRAINING OF MANAGING STAFF OF HIGHER MEDICAL EDUCATION IN UKRAINE

The article addresses the topical issue of public administration of professional training for higher medical education management personnel in Ukraine. It explores the current state and development prospects of the training system for managers of higher medical education institutions, and identifies priority areas for its improvement. The relevance of the research is determined by the need to provide the Ukrainian healthcare system with highly qualified managers capable of effectively managing higher medical education institutions in the context of dynamic changes and integration into the European and world educational and scientific space. The article defines the main approaches and mechanisms for implementing state policy in the field of healthcare and higher medical education. It identifies the directions for improving the organizational, legal, and economic mechanisms of state regulation of professional training for management personnel of higher medical institutions in Ukraine in terms of clarifying the content of the key research concepts "management personnel of higher medical education institutions" and "state administration of professional training for management personnel of higher medical education institutions". It is determined that the reforming and development of the healthcare and higher medical education sector of Ukraine in the context of integration into the European and world educational and scientific space requires the preparation of a new generation of managers - healthcare managers. It is determined that this category of managers includes vice-rectors and heads of relevant scientific, educational-methodological and educational commissions, deans and vice-deans of faculties, heads of departments and other structural units. The formation of a comprehensive mechanism of state administration of professional training for management personnel of higher medical education institutions should be carried out on the basis of such principles as scientific justification, legality, common interests and values, consistency, comprehensiveness, systematicity, subsidiarity, transparency, innovation, adequacy, efficiency, and responsibility. The article analyzes the features of the system of state administration of professional training for management personnel of higher medical education institutions in Ukraine and abroad. Based on a comparative analysis of management training systems in 6 developed countries of the world, it is proved that the system of professional training and advanced training of management personnel of higher medical education institutions should function in accordance with the current trends in the healthcare sector and the field of higher medical education, comply with the implementation of state policy principles, and be systematic. Statistical analysis of the dynamic changes in the indicators of provision with higher medical education institutions and medical institutions over the years of Ukraine's independence demonstrates the need for joint coordination and cooperation to coordinate the efficiency of the healthcare system. Thus, the article reveals the essence and features of state administration of professional training for management personnel of higher medical institutions, analyzes the regulatory framework governing this area, and identifies the main areas for improving the training system for managers of higher medical education institutions, namely: Updating the content and forms of training; Introduction of innovative teaching methods; Improvement of teachers' qualification; Strengthening the practical focus of training; Development of international cooperation.

Fusing angular features for skeleton‐based action recognition using multi‐stream graph convolution network

AbstractDistinguishing similar actions has been a challenging challenge in skeleton‐based action recognition. Since the joint coordinates in these actions are similar, it is difficult to accomplish the recognition task using traditional joint features. To address this issue, the use of angle features to capture subtle nuances in various body parts, along with a critical angle enhancement module that assigns weights to different angle feature representations for a given action are proposed, highlighting the critical angle feature representation. The approach is evaluated using a three‐stream ensemble method on three large action recognition datasets, NTU‐RGB+D, NTU‐RGB+D 120, and Kinetics‐400. The experimental results demonstrate that incorporating angular information can effectively complement joint and skeletal features, leading to improved recognition of similar actions and enhanced model performance and robustness.

An overview of Graph Convolutional Networks in skeleton-based action recognition

The field of research is currently focused on human activity recognition. Hence, numerous pertinent literature reviews have expounded upon the multifaceted nature of data, the process of selecting feature vectors, and the advantages and disadvantages of classification networks. Graph Convolutional Networks (GCNs) have demonstrated significant efficacy in the domain of human action recognition. In recent years, with the rapid development of 3D skeleton data collection, a plethora of studies in action recognition based on skeleton data have emerged. Skeleton data consists of three-dimensional coordinates of multiple spatiotemporal skeletal joints, making it an effective representation of kinematics. It can be easily acquired through low-cost depth sensors and also directly extracted from two-dimensional images using video-based pose estimation algorithms, attracting widespread attention. As relational networks continue to evolve, GCNs have been applied to various fields, including human action recognition. GCNs have demonstrated significant advantages in feature extraction from skeleton data. However, using GCNs alone may have various limitations. Therefore, in recent years, many enhancement measures for GCNs have emerged. This review aims to summarize the research achievements of Graph Convolutional Network improvements in the field of human action recognition in recent years. It intends to assist future researchers in quickly organizing their research ideas, facilitating the generation of new results.

SkeletonGait: Gait Recognition Using Skeleton Maps

The choice of the representations is essential for deep gait recognition methods. The binary silhouettes and skeletal coordinates are two dominant representations in recent literature, achieving remarkable advances in many scenarios. However, inherent challenges remain, in which silhouettes are not always guaranteed in unconstrained scenes, and structural cues have not been fully utilized from skeletons. In this paper, we introduce a novel skeletal gait representation named skeleton map, together with SkeletonGait, a skeleton-based method to exploit structural information from human skeleton maps. Specifically, the skeleton map represents the coordinates of human joints as a heatmap with Gaussian approximation, exhibiting a silhouette-like image devoid of exact body structure. Beyond achieving state-of-the-art performances over five popular gait datasets, more importantly, SkeletonGait uncovers novel insights about how important structural features are in describing gait and when they play a role. Furthermore, we propose a multi-branch architecture, named SkeletonGait++, to make use of complementary features from both skeletons and silhouettes. Experiments indicate that SkeletonGait++ outperforms existing state-of-the-art methods by a significant margin in various scenarios. For instance, it achieves an impressive rank-1 accuracy of over 85% on the challenging GREW dataset. The source code is available at https://github.com/ShiqiYu/OpenGait.

Disentangled Diffusion-Based 3D Human Pose Estimation with Hierarchical Spatial and Temporal Denoiser

Recently, diffusion-based methods for monocular 3D human pose estimation have achieved state-of-the-art (SOTA) performance by directly regressing the 3D joint coordinates from the 2D pose sequence. Although some methods decompose the task into bone length and bone direction prediction based on the human anatomical skeleton to explicitly incorporate more human body prior constraints, the performance of these methods is significantly lower than that of the SOTA diffusion-based methods. This can be attributed to the tree structure of the human skeleton. Direct application of the disentangled method could amplify the accumulation of hierarchical errors, propagating through each hierarchy. Meanwhile, the hierarchical information has not been fully explored by the previous methods. To address these problems, a Disentangled Diffusion-based 3D human Pose Estimation method with Hierarchical Spatial and Temporal Denoiser is proposed, termed DDHPose. In our approach: (1) We disentangle the 3d pose and diffuse the bone length and bone direction during the forward process of the diffusion model to effectively model the human pose prior. A disentanglement loss is proposed to supervise diffusion model learning. (2) For the reverse process, we propose Hierarchical Spatial and Temporal Denoiser (HSTDenoiser) to improve the hierarchical modelling of each joint. Our HSTDenoiser comprises two components: the Hierarchical-Related Spatial Transformer (HRST) and the Hierarchical-Related Temporal Transformer (HRTT). HRST exploits joint spatial information and the influence of the parent joint on each joint for spatial modeling, while HRTT utilizes information from both the joint and its hierarchical adjacent joints to explore the hierarchical temporal correlations among joints. Extensive experiments on the Human3.6M and MPI-INF-3DHP datasets show that our method outperforms the SOTA disentangled-based, non-disentangled based, and probabilistic approaches by 10.0%, 2.0%, and 1.3%, respectively.

Human–machine interaction and implementation on the upper extremities of a humanoid robot

Estimation and tracking the various joints of the human body in a dynamic environment plays a crucial role and it is a challenging task. Based on human–machine interaction, in the current research work the authors attempted to explore the real-time positioning of a humanoid arm using a human pose estimation framework. Kinect depth sensor and media pipe framework are used to obtain the three-dimensional position information of human skeleton joints. Further, the obtained joint coordinates are used to calculate the joint angles using the inverse kinematics approach. These joint angles are helpful in controlling the movement of the neck, shoulder, and elbow of a humanoid robot by using Python-Arduino serial communication. Finally, a comparison study was conducted between the Kinect, MediaPipe, and real-time robots while obtaining the joint angles. It has been found that the obtained result from the MediaPipe framework yields a minimum standard error compared to Kinect-based joint angles.

Motion planning and control of planar serial chain articulating locomotion system

This paper addresses two important problems in motion planning and control of serial chain planar articulating locomotion systems moving on a flat surface. Locomotion systems generally use closed curve cyclic gaits to perform maneuvers in the environment. The geometric mechanics tools are used to identify the cyclic gaits. Firstly, a motion control approach is presented using a single cyclic gait parametrized with variable gait parameters. The parameterized gait is used to drive the system along a continuous trajectory with varying curvature. On the other hand, the proposed approach presents how the gait parameters can be controlled to smoothly track a continuous trajectory. Secondly, this paper presents a joint coordination approach to generalize the height function based approach to design cyclic gaits for the system having joint space with more than two degrees of freedom. Using joint coordination approach, cyclic gaits can be designed for different motion behaviors such as longitudinal motion, sideways motion and rotation in place. The joint coordination approach also helps generalizing the proposed motion control approach to planar serial chain articulating robots with any even number of joints.

When the Mess Is the Message: Simultaneous Signing in an ASL Multiparty Interaction

Abstract: This article presents the results of a microanalysis of sequences when two or more deaf signers overlap. This contribution focuses on cooperative overlap —which consists of extended moments of turn-exchanges that move along the unfolding discourse while cohering interlocutors in relation to each other. This aspect of signed interaction has received little scholarly attention but appears to be one crucial part of the "enchronic glue" (Enfield 2022) of language binding interactions (and interactants) together. Little is known about the specific underpinnings of these seemingly messy interactive moments. We seek here to understand how such extended overlaps are achieved by deaf coparticipants where the outcome results in a forward move of the interaction. A total of thirty-three instances of collaborative overlapping signing were identified, accounting for approximately seven out of the seventy-five minute multiparty interaction between four American Sign Language (ASL) signers. Out of these, specific interactional sequences were analyzed using techniques from ethnomethodology and conversation analysis to answer the following question: What embodied practices are used to negotiate overlaps while maintaining interactional synchrony? In addition to lexical repetition strategies identified in earlier work, these closely timed sequences of overlap are successful because they engage multiple articulators coordinated across signers. Further, it appears that these practices that are symbolic of the joint coordination of co-constructed discourse are a behavior that signers both willingly engage in to achieve specific interactive tasks, namely clarification-seeking, confirmation, and coordinated depiction. Results do not only account for how deaf signers achieve collaborative overlaps but also reveal the interactive reasons why signers engage in these seemingly messy moments of interaction.

Why did the “world of the 1960s” disappear? About the reasons for the decline of the youth protest movement in late 60s of the XX century in the countries of Western Europe and the USA

The article is about the reasons of the decline of the Western European and USA youth protest movement in late 60s of the 20th century. According to the authors, the main reasons for the decline of the Movement are: the spontaneity of the protests, the absents of the joint coordination of actions, mistrust political institutions, the narrowness and limitations of ideas and slogans). The change of attitude towards the youth by the government circles and public of the Western countries in the early 1970s played an important role in the minimization of protest activity. As the result of it was the development of a fundamentally new youth policy based on the “whip and gingerbread” method: on the one hand, there was a strengthening of the repressions against riots participants, and on the other hand, the involvement of youths representative into political, state, business and public institutions with the aim of integration began protest activists in public life. Finally, the new trends in the social and political development of the Western countries in early 1970s become the significant factor in the decline of the protest movement. Such trends included changes in economic, political and cultural interactions in countries of Western Europe and USA, in particular the deterioration of the economic situation, as well as the extension of the social elite at the expense of students and graduates of technical and economic faculties. Finally, the new trends in the social and political development of the Western countries in early 1970s becаme the significant factor in the decline of the protest movement, in particular the deterioration of the economic situation, as well as the expansion of the social elite at the expense of students and graduates of technical and economic faculties. This contributed to the further erosion of the social base of the protests and the focus of youth on their careers.