Static State Research Articles

In vivo quantification of human aqueous veins by enhanced depth imaging optical coherence tomography and optical coherence tomography angiography images.

To investigate the aqueous vein in vivo by using enhanced depth imaging optical coherence tomography (EDI-OCT) and optical coherence tomography angiography (OCTA). In this cross-sectional comparative study, 30 healthy participants were enrolled. Images of the aqueous and conjunctival veins were captured by EDI-OCT and OCTA before and after water loading. The area, height, width, location depth and blood flow of the aqueous vein and conjunctival vein were measured by Image J software. In the static state, the area of the aqueous vein was 8166.7±3272.7 µm2, which was smaller than that of the conjunctival vein (13 690±7457 µm2, P<0.001). The mean blood flow density of the aqueous vein was 35.3%±12.6%, which was significantly less than that of the conjunctival vein (51.5%±10.6%, P<0.001). After water loading, the area of the aqueous vein decreased significantly from 8725.8±779.4 µm2 (baseline) to 7005.2±566.2 µm2 at 45min but rose to 7863.0±703.2 µm2 at 60min (P=0.032). The blood flow density of the aqueous vein decreased significantly from 41.2%±4.5% (baseline) to 35.4%±3.2% at 30min but returned to 45.6%±3.6% at 60min (P=0.021). The structure and blood flow density of the aqueous vein can be effectively evaluated by OCT and OCTA. These may become biological indicators to evaluate aqueous vein changes and aqueous outflow resistance under different interventions in glaucoma patients.

Optimization of frame structure coach 29/34 seats in static durability state

The stress and deformation of the body frame and chassis frame of a coach subjected to bending, torsion, emergency braking and returning must be considered during the design and manufacture of passenger vehicles. The model of 29/34-seat coach in this investigation is a newly designed vehicle based on the old 29/34-seat coach; the most significant change has been to the chassis. It is vital to ensure it remains safe and durable when the vehicle operates on the road in the 4 cases mentioned above. Therefore, the purpose of this study is to optimise and maintain in a stable state the chassis structure of the 29/34-seat coach by using the Taguchi method based on grey relational analysis. This study has as design variables changes to the number of crossbars on the roof and the thickness of those bars, as the goal is to reduce vehicle weight while ensuring chassis durability. The finite element analysis applied the OptiStruct module of HyperMesh to analyse deformation and stress of the coach chassis. The optimal outcomes indicated that the error between predictive value and the optimal value of the grey relational grade of the proposed optimisation method and the regression analysis are 6% and 1.05%, respectively. The finite element analysis results indicated that when the design variables changed, the deformation and stress of the chassis changed significantly. The proposed optimisation method greatly reduced the deformation and stress of the vehicle. The optimal values of deformation and stress are also recorded in 4 cases: for the bending process 9.675 mm and 153.61 MPa were recorded; for the torsion process, 11.849 mm and 168.61 MPa; for the braking process, 10.569 mm and 161.66 MPa; for the rotation process, 16.162 mm and 200.5 MPa. The Taguchi method based on grey relational analysis helped to reduce vehicle weight by 11.5%. These results are comparable to previous publications.

Parametric uncertain LTI systems: an LMI optimisation formulation for robust feedback control design

This article considers the following problems for a parametric uncertain (affine) linear time-invariant system. The first problem is: Let a feedback gain matrix be designed such that the states of the closed loop system satisfy the specified transient performance bounds. Then, compute a ball in the uncertain parameter space such that for all parameter perturbations within it, the state response continues to satisfy the same transient performance bounds. The second problem is on the synthesis of a robust static state feedback control, which i) minimises the norm of the gain matrix, ii) maximises the radius of the ball in the uncertain parameter space, and iii) ensures achieving specified transient performance in the closed loop. For this, a sub-optimal linear matrix inequality optimisation is formulated. The developed results are demonstrated with numerical examples. It also highlights how the proposed methodology can be applied to design robust static state feedback control for a polytopic uncertain system.

Experimental evaluation of the thermal effect on dynamic behavior of travertine rock

When an engineering structure regarding a rock is affected by dynamic loads (due to the occurrence of natural hazards, such as earthquakes and landslides, or man-made hazards, such as explosions or impacts), correct prediction of changes in the strength behavior and deformability of the rock relative to its static state is necessary for reducing the damages and costs. On the other hand, rocks are always influenced by environmental conditions, such as temperature changes due to fire and weather during their lifetime, which should be considered when using them. In these cases, the mechanical behavior of the rock can usually be determined under different loading and environmental conditions using stress–strain curves. This study investigates rocks’ dynamic strength and deformability behavior at different loading rates and temperatures. For this purpose, 30 travertine rock samples from the Torshab mine, located in the Markazi province of Iran, were first heated up to 100°C, 200°C, 400°C, 800°C, and 1000°C (six temperatures), and then subjected under the impact pressure with different loading rates from (five) 11 m/s to 15 m/s using the split Hopkinson pressure bar test. Comparing the obtained dynamic stress–strain curve shows that at a constant loading rate, increasing the temperature, especially at higher temperatures, reduces the dynamic strength and increases the rock’s deformability. Moreover, in all cases, at a constant temperature, increasing the loading rate, especially at higher rates, increases the rock’s dynamic strength and deformability.

The influence of body biomechanics on the geometry of clothing patterns

Research findings in the field of clothing design underline that a garment must ensure a high level of comfort as it interacts with the shape of the human body, regardless of whether the person is in a static or dynamic state. For economic, medical and psychological reasons, it is essential that a garment fits well and adapts to the wearer’s body shape in terms of 3D geometry, volume and structure (there are areas where the garment is very close to the body and areas where it is away from the body). Several factors need to be taken into account when producing various soft goods, including garments: factors related to the client (age, posture, proportions and conformation, type and frequency of movements, medical problems, physical disabilities, etc.) and the product (destination, condition of use, characteristics of materials and accessories, etc.). This paper presents the influence of the biomechanics of the human body on the 3D shape of a garment. The geometry and the size of the garment patterns must be determined taking into account the details of the model (silhouette, destination, structure, types of materials, etc.) and, above all, the movement of the human body expressed in terms of the absolute values of the changes in its dimensions or dynamic effects.

Study on Hydrogen Flow and Heat Transfer in Underground Salt Cavern Hydrogen Storage

Hydrogen energy is a green, low-carbon, widely used secondary energy with abundant sources, and is gradually becoming one of the important carriers of energy transformation. The safe and efficient storage of hydrogen energy is particularly important. Underground hydrogen storage technology has received widespread attention due to its large scale and low comprehensive cost. Salt cavern hydrogen storage has good sealing performance, stable structure, and flexible operation, making it the most promising choice for large-scale underground hydrogen storage. According to the thermodynamic characteristics of hydrogen, a heat transfer model of hydrogen flow in salt cavern hydrogen storage is established. Three operating conditions, namely, hydrogen injection, static state, and hydrogen production, are simulated and calculated, and the flow field characteristics of hydrogen under different operating conditions are determined, providing technical support for the research on the design of hydrogen injection and production schemes for salt cavern hydrogen storage.

Poster Session: Event-related Changes in Pupil Size in a Simulated Air Refueling Task.

There are many factors that influence the behavior of the pupil, but it is functionally an instrument of the visual system; its fundamental role is to balance light and image quality. Though it is common to use pupil size as a measure of other operator-state parameters such as cognitive workload or stress, its role in the visual system can complicate this. It may be more useful to assess dynamic, rapid changes in pupil size in response to workload or stress related events. Here, we measured pupil size velocity in 14 participants who were engaged in an aerial refueling simulation on a 3D display. Refueling collisions (when the fuel nozzle hits the receiver aircraft outside of the refueling receptacle) were recorded, and the pupil velocity at all time-points 10 seconds prior and 10 seconds post-collision were averaged to calculate the event-related change in pupil velocity. On average, there was a -0.49 mm/sec spike in pupil velocity that began 0.39 seconds after the collision and lasted 1.62 seconds before returning to stasis. This suggests that the collision caused a rapid pupil constriction, indicating a stress related change. Approximately 2 seconds post-collision, the pupil began to drift back toward its static state, showing a quick return to its role in promoting good image quality. These data represent a novel way of considering the pupil in the context of its many influences and suggests that rapid spikes in pupil size may indicate an increase in operator stress.

Analysis of cord stress during tire dynamic longitudinal slip

Selected 215/55 R17 radial tires for material test to obtain relevant material parameters. Used these parameters to build a finite element model and conduct longitudinal slip simulation. The relationship between longitudinal force and slip rate at different speeds and loads was determined by tire longitudinal slip tests. Then the longitudinal slip simulation results were compared with the test results to verify the feasibility of the model. The circumferential and axial rebar force of the belt layer at different speeds and the extreme value of the circumferential rebar force on the reverse-envelope of different skeleton materials were analyzed. The results show that: in the static state, the cord force of the belt layer had shown a trend consistent with the direction of the cord arrangement. As the speed increased, the belt cord force exhibited significant fluctuations and asymmetry. The rebar force of the turn-up points on the belt and ply is significantly smaller compared to the fetal crown ply. The rebar force at the fetal crown and belt wrapping points at 60 km/h was smaller than at 40 km/h and 80 km/h. The cord force of the fetal crown ply and the belt ply is much more affected by the load than that of the ply.

Advanced surface engineering of titanium materials for biomedical applications: From static modification to dynamic responsive regulation.

Titanium (Ti) and its alloys have been widely used as orthopedic implants, because of their favorable mechanical properties, corrosion resistance and biocompatibility. Despite their significant success in various clinical applications, the probability of failure, degradation and revision is undesirably high, especially for the patients with low bone density, insufficient quantity of bone or osteoporosis, which renders the studies on surface modification of Ti still active to further improve clinical results. It is discerned that surface physicochemical properties directly influence and even control the dynamic interaction that subsequently determines the success or rejection of orthopedic implants. Therefore, it is crucial to endow bulk materials with specific surface properties of high bioactivity that can be performed by surface modification to realize the osseointegration. This article first reviews surface characteristics of Ti materials and various conventional surface modification techniques involving mechanical, physical and chemical treatments based on the formation mechanism of the modified coatings. Such conventional methods are able to improve bioactivity of Ti implants, but the surfaces with static state cannot respond to the dynamic biological cascades from the living cells and tissues. Hence, beyond traditional static design, dynamic responsive avenues are then emerging. The dynamic stimuli sources for surface functionalization can originate from environmental triggers or physiological triggers. In short, this review surveys recent developments in the surface engineering of Ti materials, with a specific emphasis on advances in static to dynamic functionality, which provides perspectives for improving bioactivity and biocompatibility of Ti implants.

Temporal Pixel-Level Semantic Understanding Through the VSPW Dataset.

Scene understanding through pixel-level semantic parsing is one of the main problems in computer vision. Till now, image-based methods and datasets for scene parsing have been well explored. However, the real world is naturally dynamic instead of a static state. Thus, learning to perform video scene parsing is more practical for real-world applications. Considering that few datasets cover an extensive range of scenes and object categories with temporal pixel-level annotations, in this work, we present a large-scale video scene parsing dataset, namely VSPW (Video Scene Parsing in the Wild). To be specific, there are a total of 251,633 frames from 3,536 videos with densely pixel-wise annotations in VSPW, including a large variety of 231 scenes and 124 object categories. Besides, VSPW is densely annotated with a high frame rate of 15 f/s, and over 96% of videos from VSPW have high spatial resolutions from 720P to 4 K. To the best of our knowledge, VSPW is the first attempt to address the challenging video scene parsing task in the wild by considering diverse scenes. Based on our VSPW, we further propose Temporal Attention Blending (TAB) Networks to harness temporal context information for better pixel-level semantic understanding of videos. Extensive experiments on VSPW well demonstrate the superiority of the proposed TAB over other baseline approaches. We hope the new proposed dataset and the explorations in this work can help advance the challenging yet practical video scene parsing task in the future. Both the dataset and the code are available at www.vspwdataset.com.

Management of the Flabby Ridge Using a Special Impression Technique

The flabby ridge is commonly observed in the anterior region of the maxillary arch in fully edentulous patients. It is characterised by non-adherent hypertrophic mucosal lesions overlying the underlying bone, often with excessive bone resorption. Management of the flabby ridge is essential prior to the placement of a definitive prosthesis, whether by surgical resection or the use of specific prosthetic methods. This management aims to ensure stability and optimal retention of the prosthesis. In order to determine the type of intervention to be chosen, a thorough interview and clinical examination are carried out. Several parameters are considered, such as the volume of the flabby ridge, the degree of underlying bone resorption, the type of prosthetic rehabilitation planned and the presence of any contraindications to surgery. These factors will guide the decision on the most appropriate treatment. In this article, we focus on a non-surgical approach to the management of the flabby ridge, which involves the selection of a specific type of impression. This impression technique aims to record the ridge in its static state, without compression or displacement, while ensuring precise muco-dynamic recording of the adjacent tissues.

A new dynamic 2D fusion model and output characteristic analysis of floating photovoltaic modules considering motion and environmental factors

As a new application form, floating photovoltaic power generation is a green and sustainable energy source with immense development potential. However, built on marine or riverine surface, the floating photovoltaic system not only faces challenges from environment factors that land-based photovoltaic system meets, but also faces challenges from the motion of the floating bodies which are caused by the continuous external forces of wind and waves. Modelling and analyzing the output characteristics of floating photovoltaic modules is desirable and useful to improve power generation efficiency. This paper presents a new dynamic 2D fusion model and analysis method for analyzing the dynamic characteristics of floating photovoltaic modules under continuous changes in motion, irradiance, and temperature caused by actual wind and waves conditions. To achieve accurate measurement of floating photovoltaic modules, the coupling relationship between the motion state and the environmental factors is established. Then the motion state modeling of floating photovoltaic modules based on multi-sensors information fusion is established to acquire the absolute attitude angle with the continuous superposition of high and low frequency motion in the geographical coordinate system. On this basis, a new dynamic 2D fusion model of floating photovoltaic modules is set up to obtain the dynamic output characteristics, which integrates mechanical motion state information with the electrical parameters. Finally, the proposed modelling and analyzing method is evaluated with experimental data. The experimental and analytical results show that the accuracy of the 2D fusion model is higher than 98.7%, the output efficiency of floating photovoltaic modules is only 94.2% compared to the static state, and power generation efficiency can be increased by 2.5% by using the proposed method. The new modelling method proposed in the paper can accurately obtain the output characteristics of the floating photovoltaic system under actual operating conditions, which can effectively improve the efficiency of power generation.

Параметрическая модель синхронного реактивного двигателя с TLA-ротором в установившихся и переходных режимах

There is considerable practical and scientific interest in synchronous reaction motors (SynRM) with TLA rotor. The core of the TLA rotor has a transversal charge, internal slots, and highly saturated areas. The configuration of the rotor slots is complex and diverse. The task to develop a parametric model of the SynRM with a TLA-rotor designed for calculation of steady-state and transient modes of the motor is relevant. The classical parametric model of SynRM based on the theory of two reactions is used. The calculation method for the parameters of the SynRM model with TLA rotor is presented. The method uses the results of field calculation of two static states of the magnetic field. The steady-state conditions of SynRM are calculated according to the engineering formulas derived from the equation of equilibrium stresses in the stator phase. The Park-Gorev equations are used to calculate the transient modes of the SynRM. Field models of the SynRM under study at longitudinal and transverse rotor positions are presented. Main harmonics of magnetic field in the gap and their dependence on armature current are calculated. Formulas to calculate the inductive parameters of armature winding and performance characteristics of SynRM are given. Differential equations to calculate processes in SynRM are given. The parametric model is used to calculate performance characteristics of SynRM, frequency start process, electromechanical process of SynRM operation in case of asymmetric power supply. The calculation results are compared with the results of field simulation of SynRM with TLA rotor in the Ansys Maxwell environment. The classical parametric model of the synchronous machine based on the theory of two reactions allows fast and high-quality analysis of steady-state and transient modes of operation of a synchronous reactive motor with TLA-rotor under various conditions of power supply and mechanical load, including abnormal ones.

A MULTI-MODAL INTENTION INTEGRATION METHOD FOR UNMANNED AERIAL VEHICLES BASED ON THE COMBINATION OF BIOELECTRICAL SIGNALS AND CONVENTIONAL HUMAN–COMPUTER INTERACTION

With the rapid development of intelligent information technology, human–computer interaction for unmanned aerial vehicle (UAV) systems has gradually developed from single-mode interaction to multi-modal interaction. Due to the problems of information ambiguity and operational redundancy in multi-modal interaction, and the inability to effectively realize the coupling of human–computer interaction of different modalities, a priority strategy for multi-modal interaction for UAV systems is proposed. Living cells or tissues, whether in a static or active state, will produce regular electrical phenomena called bioelectricity. Human–computer interaction intention recognition technology based on bioelectrical signals can significantly enhance the real-time performance and flexibility of human–computer interaction and has great development potential. The characteristics of human–computer interaction intention recognition methods based on bioelectrical signals, such as electroencephalograms (EEGs), electromyograms (EMGs), electrooculograms (EOGs), and other conventional methods are introduced and analyzed, and then the basic characteristics of single-mode interaction and multi-modal interaction are compared. Furthermore, the priority strategies for UAV systems under different interaction modes are studied based on the analysis of task value evaluation parameters. The cumulative value, urgency, and task complexity are comprehensively analyzed and evaluated, and a set of priority strategies for multi-modal interaction is integrated. Through the simulation and verification of the multi-modal human–computer interaction software of the UAV system, it is determined that the proposed priority strategy conforms to the operation intention of the user, which improves the interaction efficiency and the reliability. In noisy environments, the UAV system control can be combined with the complementary information of various interaction methods to achieve precise control, which has obvious advantages.

On Research of Cable Tension Distribution Algorithm for Four Cables - Three DOF Planar Cable-Driven Parallel Robot

One of the main concerns in controlling the cable-driven parallel robot (CDPR) mechanism is dealing with the distribution of tension on each cable, which is critical to the operation of the entire cable system. It can be said that adjusting the cable tension will determine the power consumption of the motors and the stiffness of the structure. Therefore, the problem that needs to be solved is how to handle the cable tension when the end-effector moves throughout the entire workspace. The tension of each cable needs to be adjusted properly to ensure it remains the same. Moment and force act in a static state, keeping the kinematic position of the end moving platform from being deflected and the main purpose is to ensure that the robot achieves a rigid state and eliminates vibration when moving. Because of that essential demand, this article will refer to the Quadratic programming algorithm to solve the problem of tension distribution for the Planar Cable-Driven Parallel Robot consisting of 4 cables with 3 degrees of freedom. This article will be the foundation for applying this algorithm to an 8-cable robot with 6 degrees of freedom (Spatial Cable-Driven Parallel Robot for example). At the same time, in this article, the simulation results for the algorithm will also be presented in this paper.

A Fully Self-Powered Wearable Leg Movement Sensing System for Human Health Monitoring.

Energy-autonomous wearable human activity monitoring is imperative for daily healthcare, benefiting from long-term sustainable uses. Herein, a fully self-powered wearable system, enabling real-time monitoring and assessments of human multimodal health parameters including knee joint movement, metabolic energy, locomotion speed, and skin temperature, which are fully self-powered by highly-efficient flexible thermoelectric generators (f-TEGs) is proposed and developed. The wearable system is composed of f-TEGs, fabric strain sensors, ultra-low-power edge computing, and Bluetooth. The f-TEGs worn on the leg not only harvest energy from body heat and supply power sustainably for the whole monitoring system, but also serve as zero-power motion sensors to detect limb movement and skin temperature. The fabric strain sensor made by printing PEDOT: PSS on pre-stretched nylon fiber-wrapped rubber band enables high-fidelity and ultralow-power measurements on highly-dynamic knee movements. Edge computing is elaborately designed to estimate multimodal health parameters including time-varying metabolic energy in real-time, which are wirelessly transmitted via Bluetooth. The whole monitoring system is operated automatically and intelligently, works sustainably in both static and dynamic states, and is fully self-powered by the f-TEGs.

Electrospun nanofiber mat of graphene/mesoporous silica composite for wastewater treatment

In this research, we fabricated the electrospun nanofibers based on functionalized porous graphene (FPG), modified SBA-15 (SBA/CuO), Polyvinylpyrrolidone (PVP), and Polyacrylonitrile (PAN). FPG, SBA/CuO, and PAN concentrations, and applied voltage were optimized to fabricate the nanofibers with the best morphology. The average diameter of optimized nanofibers was obtained at 124 ± 41 nm. A series of characterizations, including FE-SEM, EDX, AFM, FT-IR, XRD, TG-DTA, tensile and contact angle measurements were employed to study the structure and morphology of nanofibers. We fabricated a Nano-filter from nanofibers to remove some water pollutants including methylene blue, malachite green, potassium permanganate, copper, lead, and cadmium ions. The filtration performance of the proposed Nano-filter was examined under the optimum conditions (concentration, volume, and pH) for each of the water pollutants (R> 97%). The results of Nano-filter recycling showed that it could be reused up to 5 times with more than 90% efficiency. Experiments have demonstrated that Nano-filter has ideal performance in the removal of dyes and metal ions from factory wastewater. Besides, the static and dynamic adsorption capacities were explored, where methylene blue (112 mg/g) and lead ions (131 mg/g) had higher static states were higher than other dyes and metal ions.

ОПРЕДЕЛЕНИЕ КОЭФФИЦИЕНТА ЗАГРУЗКИ МАТЕРИАЛА В КАМЕРЕ ПОМОЛА ШАРОВОЙ БАРАБАННОЙ МЕЛЬНИЦЫ

The predominant application of ball drum mills in industrial enterprises for the comminution process of various materials, which is one of the most energy-intensive basic technological processes, is demonstrated in this scientific article. As one of the parameters that can enhance the efficiency of the comminution process, the rational quantitative ratio of grinding bodies to the material being ground is noted. To calculate the material loading coefficient in the grinding chamber, the feasibility of developing a mathematical description is shown. This allows to determine the change in the area of gaps between grinding bodies in a cross-sectional plane perpendicular to the longitudinal axis of the mill's body, as the rotational frequency changes. A mathematical description is obtained to determine the area of the ball-material load in the cross-sectional plane of the grinding chamber during the static state of the mill's body and at different rotational frequencies. Using this mathematical description, research on the change in the area occupied by the ball-material load in the transverse section of the grinding chamber during the transition of the mill's body from the static state to the operating state is conducted. Regularities of its changes for an industrial-sized mill are determined. At different values of the filling coefficient of grinding bodies, it is established that the transition of the mill's body from static to operating state leads to an increase in the area of the transverse section of the ball-material load by an amount close to 17 %. An expression is proposed to determine the material loading coefficient in the grinding chamber corresponding to its operating rotational frequency.

Sonification of a juggling performance using spatial audio

We developed a new musical instrument by equipping juggling balls with accelerometers, gyroscopes, and WiFi sensors. The system measures acceleration and rotation, allowing us to distinguish between ball movement and static states. We can determine the direction of each throw based on the acceleration data. A movement-driven instrument animates the virtual audio source position based on the throw direction. A different synthesizer is assigned to each ball, resulting in a synesthetic experience. The system integrates the juggling patterns simulator with OSC and MIDI API, allowing real-time rhythm generation and composition.

Constructing Ultrastable Metallo-Cages via In Situ Deprotonation/Oxidation of Dynamic Supramolecular Assemblies.

Coordination-driven self-assembly enables the spontaneous construction of metallo-supramolecules with high precision, facilitated by dynamic and reversible metal-ligand interactions. The dynamic nature of coordination, however, results in structural lability in many metallo-supramolecular assembly systems. Consequently, it remains a formidable challenge to achieve self-assembly reversibility and structural stability simultaneously in metallo-supramolecular systems. To tackle this issue, herein, we incorporate an acid-/base-responsive tridentate ligand into multitopic building blocks to precisely construct a series of metallo-supramolecular cages through coordination-driven self-assembly. These dynamic cagelike assemblies can be transformed to their static states through mild in situ deprotonation/oxidation, leading to ultrastable skeletons that can withstand high temperatures, metal ion chelators, and strong acid/base conditions. This in situ transformation provides a reliable and powerful approach to manipulate the kinetic features and stability of metallo-supramolecules and allows for modulation of encapsulation and release behaviors of metallo-cages when utilizing nanoscale quantum dots (QDs) as guest molecules.