Principles Of Movement Research Articles

Effect of squeeze motion on the tribo-performances of molybdenum disulfide powder lubricated textured cemented carbide specimens

Purpose This study aims to improve the lubrication performance of molybdenum disulfide powders at textured surface of cemented carbide materials, a squeeze motion of vibration assistance method was introduced and investigated. Design/methodology/approach Surface texture was fabricated on YT15 cemented carbide samples using a laser marking machine. After that, a tribological experiment was carried out on a self-built friction testing machine under different amplitude and frequency of squeeze motion conditions. Moreover, a simulation model was also established to verify the principle of squeeze motion on the lubrication performance improving of MoS2 particles at textured interfaces. Findings Analysis results indicated that surface texture on test sample can increase the storage ability of solid lubrication particles, and the lubrication film at the contact interface is more easily formed due to the reciprocating action. Squeeze motion can improve the storage ability of it due to an intermittent contact, which provides an opportunity for MoS2 particles infiltration, and then a more uniform distribution and load-bearing properties of force chain are also established and formed simultaneously. Thus, a better tribological performance at the contact interface is obtained. Originality/value The main contribution of this work is to provide a reference for the molybdenum disulfide powder lubrication with textured surface of cemented carbide materials. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0166/

A Fusion Localization System for Security Robots Based on Millimeter Wave Radar and Inertial Sensors

In smoggy and dusty environments, vision- and laser-based localization methods are not able to be used effectively for controlling the movement of a robot. Autonomous operation of a security robot can be achieved in such environments by using millimeter wave (MMW) radar for the localization system. In this study, an approximate center method under a sparse point cloud is proposed, and a security robot localization system based on millimeter wave radar is constructed. To improve the localization accuracy of the robot, inertial localization of the robot is integrated with MMW radar. Based on the concept of inertial localization, the state equation for the motion principle of the robot is deduced. According to principle of MMW localization, the measurement equation is derived, and a kinematics model of the robot is constructed. Further, by applying the Kalman filtering algorithm, a fusion localization system of the robot based on MMWs and inertial localization is proposed. The experimental results show that with iterations of the filtering algorithm, the gain matrix converges gradually, and the error of the fusion localization system decreases, leading to the stable operation of the robot. Compared to the localization system with only MMW radar, the average localization error is approximately reduced from 11 cm to 8 cm, indicating that the fusion localization system has better localization accuracy.

THE ESSENTIAL ROLE OF PHYSIOTHERAPY IN PROFESSIONAL FOOTBALL

The role of physiotherapists in professional football is critical for both the physical recovery of athletes and the implementation of strategies that promote injury prevention and enhance performance. With a comprehensive understanding of biomechanics and movement principles, physiotherapists can assess players’ performance and work closely with coaching staff to devise effective game tactics. Their expertise enables them to identify movement patterns and areas of stress that can lead to injuries, ultimately helping to minimize these risks. Education plays a vital part in the physiotherapist's responsibilities, as they teach athletes about health maintenance and the significance of injury prevention. This educational component is essential for ensuring that players can sustain a long and successful sports career. Despite progress in prevention and rehabilitation practices, studies reveal persistent gaps between clinical practice and scientific evidence. Increased regulation of the profession, coupled with a multidisciplinary approach that incorporates psychological support, emphasizes the growing importance of physiotherapy within football. Moreover, recognizing the psychological factors that influence recovery and utilizing evidence-based protocols are vital for optimizing rehabilitation outcomes. The physiotherapist’s influence extends beyond physical recovery; they are integral in fostering the overall health and well-being of athletes, which significantly impacts team performance. Moving forward, the field of physiotherapy in football must prioritize continuous professional development, the adoption of innovative practices, and the establishment of an environment that values both the physical and mental health of players.

Research on rotational rollback suppression of diamond-shaped active locking flexure mechanism (ALFM) driven by piezoelectric wafers

Abstract Piezoelectric actuators have a wide range of applications in many areas due to their advantages of fast response speed, high resolution, compact and simple structure, diverse configurations, and resistance to electromagnetic interference. However, existing piezoelectric actuators generally have large fallback, and a few researchers have applied the ALFM to the fallback suppression of actuators. In this paper, an ALFM using a piezoelectric wafer as the driving source is innovatively designed, and the structure and dimensions are simulated and optimized using Finite Element Method, according to which the piezoelectric wafer-type ALFM is used to design a new inertial piezoelectric actuator that can suppress backward movement. The motion principle of the piezoelectric actuator is theoretically analyzed, followed by the establishment of the machine dynamics model of the piezoelectric actuator and simulation with MATLAB/simulink to verify the reasonableness of the dynamics model. Finally, a series of experiments are carried out on the processed drive model, and the results show that the maximum accuracy of the actuator is 8.5 μrad, and the maximum load capacity is 160 g. The comparison experiments at 30 Hz and 40 Hz with and without the ALFM prove that the locking mechanism does supress the actuator from backing off to a certain extent, which verifies the reasonableness of the scheme proposed in this paper.

An improved Kepler optimization algorithm for module parameter identification supporting PV power estimation

Identification of photovoltaic (PV) module characteristics in solar systems is a vital task, nowadays, for optimal PV power estimation. In this paper, this challenge task has been studied using a novel advanced Kepler optimization algorithm (KOA). The standard version of KOA is adopted and assessed for getting the nine parameters of the PV triple diode model (3DM) considering three different practical PV modules. Kepler's principles of planetary motion are used by KOA to forecast the location and velocity of planets at any particular moment. However, the success rate of the KOA is not compatible, and its efficiency needs to be enhanced. As a result, an Improved KOA (IKOA) is created by incorporating an advanced mechanism of Local Escaping Operator (LEO), resulting in improved process of searching with evading local optima. This mechanism means that the exploitation approach will activate with around half of the solutions for every iteration starting at the initial phase of the iteration journey. The suggested IKOA besides the standard KOA are developed for predicting PV parameters for three distinct PV modules which are Photowatt PWP201, R.T.C France and STM6-40/36. The results corresponding to the latest algorithms are also compared with the proposed IKOA about different published works. The simulation findings reveal that the suggested IKOA exhibits notable average improvement rates for the three modules of 62.27 %, 55.1 %, and 32.12 %, respectively. Furthermore, the suggested IKOA asserts significant superiority and robustness over previously reported results.

Application of 3D Motion Graphic Design Technology of Object Simulation Human Body in Sports Teaching

In the current era, the rapid development of computer technology has brought unprecedented opportunities for innovation in physical education teaching. The introduction of computer technology not only improves the efficiency of physical education teaching but also provides more accurate and scientific means for sports training. In response to this trend, this paper proposes an innovative human body model design method and explores in detail the key implementation techniques of computer simulation of 3D motion maps, aiming to further optimize and improve the quality of physical education teaching. The design of human body models plays a crucial role in physical education teaching and training, as it can help students and teachers better understand the mechanisms and principles of human movement. By introducing computer technology, this paper can construct a more precise, dynamic, and realistic human body model that conforms to the actual motion situation. This model can simulate various movement states of the human body, providing students with an intuitive and vivid learning experience. In the classroom, teachers can use projection or virtual reality devices to display 3D motion models, allowing students to intuitively see the details and changes of motion movements, deepening their understanding of the essentials of the movements. Teachers can demonstrate different movements in real time by operating models, and explain the technical points and precautions of each movement. Students can observe the motion trajectory and posture changes of the model from multiple perspectives to improve learning efficiency. The system generates personalized feedback reports based on students’ movement data, pointing out the problems and improvement directions that students have during the exercise process. Teachers can provide more accurate guidance to students based on these feedbacks, helping them correct incorrect movements and improve their skill levels.

Effects of Using Physical Activity Applied Dancing Arts Model to Promote the Well-Being of the Elderly

This article aimed to study Effects of using Physical Activity Applied Dancing Arts Model to Promote the Well-Being of the Elderly. This is a quantitative research using the One Group Pretest-Posttest Design model of physical activity using applied dance, and a satisfaction questionnaire. The results of the study showed that form of exercise activities using applied dance to promote the well-being of the elderly. It consists of a total of 7 activities. Independent movement principle related to emotions and feelings with music. The activity was spent 16 times, 1 hour 30 minutes each. Comparative results of the mean health scores in each aspect before and after the experimental use of the exercise activity model using applied dance poses. It was found that the mean score after the experiment was higher than before the experiment. The statistical significance at the .01 level. The satisfaction in the activities was at the highest level. This research reflects the role and importance of bringing the science and art of dancing and music to apply the principles of body movement in expression to cause development or development of the physical, emotional, social and intellectual, and most importantly is to build relationships within society between individuals.

Sailing into Tranquility: The Rise of Slow Yachting in Luxury Tourism

ABSTRACT This study introduces the concept of “slow yachting” by investigating the alignment of Slow Movement principles within the luxury yachting sector. Using insights from 24 Ultra High Net Worth Individuals (UHNWIs) owning and chartering yachts, this paper explores five distinct dimensions of slow yachting: Luxurious Tranquility, Personal Retreat, Social Cohesion, Environmental Symbiosis, and Discovery Travel. The research illustrates how luxury yachting experiences embrace slow tourism principles. The study reveals the nuanced interplay between quality, authenticity, and sustainability in luxury travel experiences, establishing the foundation for a unique paradigm of mindful yachting. The theoretical implications underscore the importance of fostering mindful, immersive, and socially engaging travel experiences within the luxury yachting domain, catering to the discerning preferences of ultra-high-net-worth travelers while advocating for responsible and enriching tourism practices.

Principles of Donkey Movement

Observed through historical epochs and evolutionary periods, the movement of mammals basically developed into two groups. One group consists of ungulates (Perissodactyla), and the other group consists of ungulates (Artiodactyla). Among ungulates, wild and tame horses, wild and tame donkeys, and semi-donkeys were distinguished by the specific movement of their legs forward. We call this whole group Equiden.

Design optimization of anti-spin parachute for fighter-class aircraft

Abstract In the absence of spin wind tunnel test and model free flight test support, the traditional empirical formulas had low accuracy and large dispersion, which made it difficult to effectively support the anti-spin parachute design of fighter planes. Based on the principle of spin motion, the empirical formula is modified from two aspects: aircraft aerodynamic layout and mass characteristics. At the same time, the relationship between the parachute area and the flight weight is summarized, which makes the estimated result closer to the actual value and more applicable. In addition, aiming at the problem of excessive load in the design of anti-spin parachutes, the causes of the problem are analyzed in detail. The design criterion of the anti-spin parachute is optimized. Under the premise of ensuring the recovery effect, the need to strengthen the aircraft body structure is effectively reduced. The results show that the engineering estimation methods and design criteria of the anti-spin parachute proposed in this paper are effective after simulation and actual application and can provide technical support for subsequent anti-spin parachute design of new fighter planes.

Analysis of the fluid–structure coupling dynamic characteristics of flexible webbed wings under passive deformation

A wave glider with webbed wings (WGWWs) is a new type of unmanned surface robot that combines wave energy and solar energy as its energy supply, driven by flexible webbed wings (FWWs). Wave gliders with webbed wings are already playing an important role in marine science research. Flexible webbed wings are significant components of wave gliders with webbed wings that achieve the absorption and conversion of wave energy through bidirectional fluid–structure coupling with water flow. To address the issues of large deformations and nonconvergence under the strong coupling action of flexible webbed wings, a dynamic model of flexible webbed wings is first established on the basis of an analysis of the motion principle of a wave glider with webbed wings. The Mooney–Rivlin model was subsequently applied to describe the stress–strain relationship of a rubber hyperelastic material for flexible webbed wings. By adopting the overset method and dynamic mesh technology, employing the system coupling interface based on the data interaction platform of the ANSYS Workbench, as well as mechanical and fluid solvers, the transient dynamic characteristics of fluid–structure coupling of flexible webbed wings under different working conditions are obtained. Finally, by setting different sea conditions, the influences of wave height and period on the dynamic characteristics of flexible webbed wings are analyzed. The results indicate that the greater the wave height and the smaller the wave period are, the greater the power output of the flexible webbed wings is. Additionally, the influence of the wave height ratio period on the dynamic characteristics of flexible webbed wings is more pronounced.

A study on radial oil seal leakage failure due to viscoelasticity under dynamic eccentricity

PurposeThis study aims to investigate the causes of leakage in radial oil seals under dynamic eccentricity, elucidate the influence of operating parameters on leakage failure and develop methods for predicting and preventing such leakage.Design/methodology/approachBased on the principle of cam motion and considering viscoelasticity, develops a motion model of the compression and release of the shaft seal and proposes a method to determine its failure. In addition, this study quantifies the leakage gap and formulates a quantitative calculation model to accurately determine the location and shape parameters of the leakage gap.FindingsLeakage gaps predominantly occur during the release phase of the shaft seal. Their presence can be identified by comparing the descending times of the seal and the shaft during this phase. An increase in rotation speed and eccentricity heightens the likelihood of gap formation, with both the dimensions and leakage rate of the gap increasing as these factors escalate. Eccentricity, in particular, has a more pronounced effect on gap formation.Originality/valueThis study clarifies the failure mechanisms of radial oil seals under dynamic eccentricity and introduces a criterion for identifying leakage gaps, providing valuable theoretical guidance for the design and optimization of radial oil seals.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0192/.

No dog in this fight: Interrogating Ethiopia’s calculated neutrality towards the Russia-Ukraine war

ABSTRACT Ethiopia has officially adopted a neutral position in the Russia-Ukraine war in line with the principles of the Non-Aligned Movement (NAM). Despite the centrality of sovereignty and territorial integrity in Ethiopia’s foreign policy, the government has avoided publicly castigating Russia for its assault on Ukraine’s sovereignty. This stance constitutes a sovereignty paradox when viewed in light of Ethiopia’s demonstrated commitment to its own sovereignty which has seen it fight three wars against Italy, Somalia and Eritrea, and the country’s advocacy to institutionalize sovereignty norms at the global level. This contribution argues that Addis Ababa’s reliance on Moscow’s arms supplies and its diplomatic cover in the United Nations Security Council in the context of the Tigrayan conflict compromised its ability to defend the principle of sovereignty.

Bayesian optimization for quick determination of operating variables of simulated moving bed chromatography

The Simulated Moving Bed (SMB) is a continuous chromatographic separation process that operates on the principle of counter-current movement between the solid and liquid phases. Due to periodic switching of feed and product ports across numerous connected columns, adjusting SMB operating variables such as feed and product flow rates and switching time to achieve desired separations is challenging. While equilibrium theory can help narrow the search space, obtaining essential information such as accurate adsorption isotherms is crucial. This requirement, combined with often highly stringent production specifications, makes it challenging to identify even a feasible operating condition, let alone an optimal one. Trial-and-error-based approaches are often impractical as reaching cyclic steady state can be time-consuming, and any waste produced during this period can lead to significant economic losses. While rigorous dynamic models are available, they are computationally intensive and often do not accurately mirror actual process behavior. To address these challenges, the use of Bayesian Optimization (BO) is proposed to sequentially approach optimal SMB operation. Furthermore, it is suggested to employ the simpler True Moving Bed (TMB) model as a prior for the BO, which significantly accelerates convergence. This approach is demonstrated on an SMB process for cresol separation. Initially, the effectiveness of the BO using the TMB model is examined to gain insights into its behavior. Subsequently, we apply BO to the rigorous SMB model, informed by prior knowledge from the TMB model. Our results show that the developed BO framework rapidly converges to the optimal operating parameters that satisfy the purity constraints. We examine the efficiency improvements over various search algorithms and highlight the advantages of using the TMB model as a prior.

A Grouping and Aggregation Modeling Method of Induction Motors for Transient Voltage Stability Analysis

Induction motors are the most common type of motor in power systems, constituting approximately 70–90% of the dynamic loads, making them significant contributors to system dynamics. In transient voltage stability analysis, dynamic equivalent models are commonly used to simplify the representation of a group of induction motors. This paper presents a method for the grouping and aggregation of induction motors at a common bus. Firstly, grouping rules are provided for clustering induction motors into several subgroups based on the mechanical principles of rotor force and motion, and aggregation rules are provided for aggregating a motor subgroup into a single-unit model based on the relationship between voltage drop and power transmission in distribution networks. Secondly, guided by the grouping rules, high-speed remaining electromagnetic torque and low-speed remaining electromagnetic torque are defined as new clustering indicators, and an adaptive K-means clustering method using silhouette coefficient verification is introduced to obtain the optimal motor subgroups. Thirdly, guided by the aggregation rules, a dynamic equivalent method is further introduced to obtain the equivalent single-unit model from a motor subgroup. Lastly, a transient voltage stability simulation in a typical distribution network is presented to illustrate that the proposed clustering and equivalent methods are more reasonable, accurate, and effective than traditional methods, as the obtained model has better dynamic characteristics and can more accurately reproduce the process of voltage collapse.

Comprehensive modeling of corkscrew motion in micro-/nano-robots with general helical structures

Micro-/nano-robots (MNRs) have impressive potential in minimally invasive targeted therapeutics through blood vessels, which has disruptive impact to improving human health. However, the clinical use of MNRs has yet to happen due to intrinsic limitations, such as overcoming blood flow. These bottlenecks have not been empirically solved. To tackle them, a full understanding of MNR behaviors is necessary as the first step. The common movement principle of MNRs is corkscrew motion with a helical structure. The existing dynamic model is only applicable to standard helical MNRs. In this paper, we propose a dynamic model for general MNRs without structure limitations. Comprehensive simulations and experiments were conducted, which shows the validity and accuracy of our model. Such a model can serve as a reliable basis for the design, optimization, and control of MNRs and as a powerful tool for gaining fluid dynamic insights, thus accelerating the development of the field.

Light-driven soft crawling robots capable of multidirectional locomotion and cargo transport

This work presents a liquid crystal elastomer (LCE)-based light-driven crawling robot capable of rapid multidirectional locomotion and cargo transport. The proposed LCE device consists of two small front legs, two large rear legs, and a concave cargo platform connecting the legs. The device’s locomotion, inspired by the principle of snake-like rectilinear movement, is generated by activating the rear legs with periodic near-infrared (NIR) illumination. The device’s structure was formed monolithically using a lithography-based molding process followed by an LCE stretching process for shape programming. To enhance NIR absorption efficiency, the rear end of the device was coated with a photothermal film consisting of acrylic-based black paint and liquid metal nanoparticles. The device’s speed, which exceeds two body lengths per minute, is among the fastest recorded in published LCE-based, light-driven crawling devices. Furthermore, the device can change the locomotion direction by controlling the actuation sequences of NIR illumination on the rear legs. This research also demonstrated and characterized the device’s load-carrying capability, as it was able to move at about half its maximum speed while carrying a load heavier than itself.

Heart, Center of the World, and the Principle of Motion: from Aristotle to Kepler and Galileo

Heart, Center of the World, and the Principle of Motion: from Aristotle to Kepler and Galileo

КЛІМАТИЧНІ ОБМЕЖЕННЯ ЕКОНОМІЧНОГО ЗРОСТАННЯ ЯК ВИКЛИКИ ФІНАНСУВАННЯ МІЖНАРОДНИХ ІНВЕСТИЦІЙНИХ ПРОЄКТІВ У СФЕРІ ЦИРКУЛЯРНОЇ ЕКОНОМІКИ

The purpose of the article is to determine the impact of climate change on (macro)economic interdependencies, such as: supply and demand balance; production and consumption; price stability; financial stability, etc. The globalization of production and supply chains, the formation of a new international division of labor (global production and industrial centers VS global centers of trade in services) leads to a distortion of the geography of greenhouse gas emissions. At the same time, at the level of international institutions and the policies produced by them, the largest consumers of carbon-rich products are mistakenly or deliberately not recognized as responsible for the aggravation of the problem of global warming, instead, the belief of "global responsibility for climate change" has been formed, and thus the internationalization of the policy to combat climate change, adaptation to them and the minimization of their manifestation involves forced greening of monetary and credit and budgetary and tax policies, which, in turn, has a significant impact not only on the macroeconomic environment, but also on other types of policies - structural, industrial, foreign economic, export, energy, etc. The macroeconomic interdependencies that arise in the process of the impact of technological changes (industrial revolutions) on climate change are considered, which creates the need to develop a policy of adaptation to climate change, which is financially costly and requires significant investments in order to adequately resist the accompanying risks (risks can be directly related to the damage caused by climate change, "physical risks" that can affect the insurance and banking sectors, the logistics services sector). The policy of mitigating the consequences of climate change involves the deliberate limitation of economic activity or the introduction of circular models in the economy in order to reduce its impact on the climate. An alternative is the policy of green and energy transition, which is implemented through the introduction of green technologies or technologies based on renewable energy sources, which simultaneously contribute to economic growth, but also lead to a reduction in greenhouse gas emissions. It has been established that the imperative of sustainable development and the green agenda, which are advancing at the level of international economic policy, transform the motivational principles of international capital movement. The circular transition affects various macroeconomic channels, such as investment, savings, consumption, employment, price level, trade, each of which can affect the overall macroeconomic situation and economic (financial, price) stability. From the point of view of price stability, climate change may increase the price of the food basket, which will affect the most vulnerable sections of the population, and may lead to an increase in extreme poverty and destitution, thus provoking new flows of climate migrants. Both the physical manifestations of climate change (climate crises, disasters, droughts, floods, etc. affect the yield of agricultural crops, and changing weather conditions affect the collection and preservation of crops), and climate change policies have a direct and indirect impact on inflation, increasing its volatility. As the risks to financial stability escalate, there is a call for revisions to the targeting approaches of central banks, which are already making changes to their mandates. The existing contradictions between the goals of the Central Bank, which are to achieve financial and price stability, and the circular transition as a component of the green and energy transitions in the EU are highlighted.

EVALUATION OF THE ECONOMIC IMPACT OF A COUNTRY`S ACCESSION TO THE SCHENGEN AREA – THE CASE OF BULGARIA

The Schengen agreement further strengthens the implementation of the principles of free movement of goods, services and persons provided in the EU and beyond. This intergovernmental agreement offers a lot of challenges that need to be examined for building understanding of the complexity of consequences of a large magnitude. The aim of this study is to develop and apply a comprehensive methodology in order to evaluate the economic effects of a country`s accession to the Schengen area. The study explores different types of economic implications, including direct, potential, ecological and fiscal effects. Moreover, the universality of the methodology provides for its comprehensive and wide applicability under different context and scenarios of abolition of border control. The developed methodology has been applied in order to evaluate the economic impact on Bulgaria from the country`s accession to the Schengen area.