Space Method Research Articles

Integration Design of Chinese Painting and Architectural Space Based on Virtual Reality Technology

Chinese painting elements are important elements in modern architectural design, which facilitate the integration of the entire building into the environment and present the scroll style spatial hierarchy of Chinese painting. Therefore, it is necessary to research on the integration design method of Chinese painting and architectural space based on virtual reality technology. First, the architectural space and landscape design plan images integrated with Chinese painting are imported into VTK software. Second, the median filtering method is used to filter the imported images, and a secure multi-party calculation method is used to construct building and landscape models, thus generating a database of architectural spatial layout element models. Then, for the 3D models in the database, Chinese painting elements are applied to architectural space design. Model rendering is achieved through lighting, color, atomization, and other processing to enhance the visual appeal of the models. Next, using the rendered 3D models of buildings and landscapes, a virtual interactive architectural spatial environment background is achieved through the freehand artistic conception concept and framing techniques in Chinese painting. Finally, we design a multi-sensory visual interactive interface based on virtual reality to display the results of the architectural spatial environment scenery to users. The experimental results show that this method has high modeling and rendering accuracy, and can achieve landscape layout browsing from different angles, improving user experience.

Dust removal method for open space of fully mechanized mining face: A cutting area pressure balance method

Dust removal method for open space of fully mechanized mining face: A cutting area pressure balance method

Controllable design and evaluation of Voronoi-based irregular porous scaffolds for bone restoration

The Voronoi-based irregular porous scaffolds (VIPS) for bone restoration often suffer from uncontrollable structural characteristics and mechanical properties. In this study, a method using spherical spaces to control the randomness of the seed points distribution was proposed to achieve controllable design of the VIPS. The irregularity ε, porosity P and average pore size D̅ of the VIPS were calculated by parametric design software Grasshopper, and the apparent elastic modulus E, equivalent compressive strength S of the VIPS were obtained by quasi-static compressive test. The functional relationships between the design parameters (spherical radius to lattice spacing ratio R/a, seed points number N and pore size coefficient K) and ε, P, D̅, E, S were established through statistical analyses. The results indicated that the VIPS designed based on the spherical space method had high controllability. Design parameters in the range of R/a∈0,0.5, N∈64,1000, and K∈0.4,0.9 allow control over the irregularity, porosity, average pore size, elastic modulus, and compressive strength of VIPS in the range of 0–0.32, 37%–96%, 200–1200 μm, 0.8–5.4GPa, 15–240MPa, respectively, and all of which could meet the structural and mechanical requirements of the VIPS for bone restoration.

Glymphatic system dysfunction in nondialysis-dependent ESRD patients with diabetic kidney disease: associations with clinical characteristics and cognitive function

Objectives To investigate glymphatic function in nondialysis-dependent ESRD (ND-ESRD) patients with diabetic kidney disease (DKD) or non-DKD using the diffusion tensor image analysis along the perivascular space (DTI-ALPS) method and choroid plexus (CP) volume to explore the associations among DTI-ALPS index, CP volume, clinical characteristics, and cognitive function. Methods 25 DKD patients, 25 non-DKD patients, and 25 healthy control (HC) were included in this study. All participants underwent cerebral MRI and cognitive assessments. Bilateral DTI-ALPS index and CP volume were calculated and were compared among three groups. Correlations among the DTI-ALPS index, CP volume, clinical characteristics, and cognitive function were analyzed. Results DKD patients had significantly lower left DTI-ALPS index (p = 0.001) and mean DTI-ALPS index (p = 0.003) than non-DKD patients. In ND-ESRD patients, there was a significant positive correlation between the left DTI-ALPS index and phosphorus (r = 0.377, p = 0.007) and attention score (r = 0.434, p = 0.002). In DKD group, the mean DTI-ALPS was positively correlated with total cholesterol (r = 0.631, p = 0.001). In non-DKD group, there was a significant positive correlation between the left DTI-ALPS index and phosphorus (r = 0.696, p < 0.001). Both DKD and non-DKD patients exhibited significant higher CP volume than HC group. In non-DKD group, CP volume was negatively correlated with mean DTI-ALPS (r = −0.535, p = 0.006) and attention score of MoCA (r = −0.538, p = 0.006). Conclusions Glymphatic system dysfunction may contribute to the pathogenesis of clinical and cognitive impairment in ND-ESRD patients especially with DKD.

Optimization Problem for Probabilistic Time Intervals of Quasi-Deterministic Output and Self-Similar Input Data Packet Flow in Telecommunication Networks

Introduction. When managing traffic at the packet level in modern telecommunication networks, it is proposed to use methods that transform a self-similar stochastic packet flow into a quasi-deterministic one. To do this, it is required to apply complex probabilistic laws of distribution of self-similar flows. From the literature, methods of balancing the network load are known, which, with the problem indicated above, contribute to increasing the efficiency of telecommunication systems. However, there is no strictly mathematical solution to find out the optimal probabilistic characteristics of the output flow, based on the input flow. The presented research is intended to fill this gap. Its objective is to create a method for determining the optimal probabilistic characteristics of the packet flow, using the minimum value of the proximity measure of the self-similar input and quasi-deterministic output flows.Materials and Methods. To solve the research problem, the parameters of the output flow distribution were selected so that the approximation function was close to 𝛿𝛿-function. The Kullback-Leibler divergence was used as a proximity measure of the input and output distributions of time intervals. Methods of set theory, metric spaces, multidimensional optimization, and teletraffic were used. The solution algorithm included minimization of the Kullback-Leibler divergence and the limit passage to 𝛿𝛿-function.Results. A probability distribution is shown — an approximation of 𝛿𝛿-function, which maintains the equality of time intervals of a quasi-deterministic output packet flow. A method for transforming a self-similar input flow into a quasideterministic output flow is presented. The Kullback–Leibler divergence was used as a measure of their proximity. The minimum of the Kullback-Leibler divergence between the input and output flows with a normal distribution was achieved in the case of equality of the mathematical expectations of these flows. Using the passage to the limit, it has been established that time interval T between packets of the quasi-deterministic output flow must be equal to the mathematical expectation of the time intervals between packets of the input self-similar flow. To obtain a quasi-deterministic flow, the passage to the limit is performed for the found value of the mathematical expectation at σ → 0.Discussion and Conclusion. The application of this method will reduce the negative impact of self-similarity of network traffic on the efficiency of the telecommunication network. The use of quasi-deterministic flows makes it possible to predict the load of network resources, which can be the basis for improving the quality of user service. Two difficulties associated with calculations and practical implementation of the solution are eliminated. Firstly, it is difficult to use the delta function as a function of the output flow distribution density. Secondly, there are no ideal deterministic flows in the operation of telecommunication networks. The proposed method has great potential in the design and optimization of communication networks.

Axisymmetric Free Vibration of Functionally Graded Piezoelectric Circular Plates

An analytical solution is presented for axisymmetric free vibration analysis of a functionally graded piezoelectric circular plate on the basis of the three-dimensional elastic theory of piezoelectric materials. The material properties are assumed to follow an exponential law distribution through the thickness of the circular plate. The state space equations for the free vibration behavior of the functionally graded piezoelectric circular plate are developed based on the state space method. The finite Hankel transform is utilized to obtain an ordinary differential equation with variable coefficients. By virtue of the proposed exponential law model, we have ordinary differential equations with constant coefficients. Then, the free vibration behaviors of the functionally graded piezoelectric circular plate with two kinds of boundary conditions are investigated. Some numerical examples are given to validate the accuracy and stability of the present model. The influences of the exponential factor and thickness-to-span ratio on the natural frequency of the functionally graded piezoelectric circular plate, constrained by different boundary conditions, are discussed in detail.

A CsWRKY48 Gene from Tea Plants Intercropped with Chinese Chestnut Plays an Important Role in Resistance to Biotic and Abiotic Stresses.

Tea plant (Camellia sinensis) is an important horticultural crop. The quality and productivity of tea plants is always threatened by various adverse environmental factors. Numerous studies have shown that intercropping tea plants with other plants can greatly improve the quality of their products. The intercropping system of Chinese chestnut (Castanea mollissima) and tea plants is an agricultural planting model in which the two species are grown on the same piece of land following a specific spacing and cultivation method. Based on a comparative transcriptome analysis between Chinese chestnut tea intercropped plantations and a pure tea plantation, it was found that the expression levels of the WRKY genes were significantly upregulated under the intercropping pattern. In this study, we cloned a candidate gene, CsWRKY48, and verified its functions in tobacco (Nicotiana tabacum) via heterologous transformation. The contents of protective enzyme activities and osmoregulatory substances were significantly increased, and the trichomes length and density were improved in the transgenic tobacco lines. This phenotype offered an enhanced resistance to both low temperatures and aphids for transgenic lines overexpressing CsWRKY48. Further analysis indicated that the CsWRKY48 transcription factor might interact with other regulators, such as CBF, ERF, MYC, and MYB, to enhance the resistance of tea plants to biotic and abiotic stresses. These findings not only confirm the elevated resistance of tea plants under intercropping, but also indicate a potential regulatory network mediated by the WRKY transcription factor.

Reconstruction of electron velocity distribution function and Gibbs entropy from electron cyclotron emission in magnetized plasmas

Abstract We propose a method for reconstructing the fluctuation components of the electron velocity distribution function, and the electron entropy, which is a functional of the fluctuation components of the electron velocity distribution function, using the harmonic spectrum from pure X-mode electron cyclotron emission (ECE) in optically thin plasmas. This formulation employs the maximum entropy method in velocity space using the Hankel transform, which converts from v⊥ space to p space (where, v⊥ and p are the electron velocity perpendicular to the background magnetic field and the index of the wavenumber in velocity space). Numerical tests validated the effectiveness of the proposed method, which is applicable across a wide range of magnetized plasma conditions, including conditions with both non-relativistic and relativistic electrons, except in cases of harmonic overlap or under optically thick conditions. Notably, this method does not require radiometer calibration for ECE measurements. This method fascilitates the experimental evaluation of electron entropy transport in fusion plasma experiments. Moreover, when combined with measurements in k-space (spatial distribution), this approach enables entropy distribution acquisition in phase space (k-p space).

Adaptive high flow oxygen therapy: New concept

Background High-flow oxygen therapy (HFOT) is increasingly utilized in clinical settings due to its potential to improve oxygenation, patient comfort and possibly outcomes in different respiratory failure states. The potential benefits of HFOT include matching the patients’ flow to reduce the work of breathing, creating airway pressure, humidification, and reducing dead space. However, it has some shortcomings including the difficulty of setting the flow to match patients’ efforts, the continuous flow does not represent normal physiologic spontaneous breathing, and the lack of traditional airway pressure monitoring. We are testing a new adaptive high-flow oxygen delivery technique “Auto Positive Airway Pressure” (Auto-PAP) where the flow delivered from the ventilator adapts to patients’ efforts taking into consideration the patients’ dead space Methods A bench study using ASL 5000 simulator, we created a single-compartment active model of a male with IBW 70 kg, with compliance of 40 ml/cmH20 and resistance of 10 cmH2o/L/s. The respiratory rate was set at 20 bpm, with inspiratory time of 1 second. Muscle pressure (Pmus) was gradually increased by increments of 5 cmH2O from 5 to 50. Adaptive high flow mode (Auto PAP) using a Bellavista 1000e ventilator (Zoll MA, USA) using a large bore nasal cannula to an adult-sized mannequin nose that was connected to the lung simulator. Pearson correlation coefficient was used in correlating the Pmus to the maximum, mean flow and pressure, and the simulator to the ventilator flow. Results There was significant strong correlation between the Pmus and the maximum flow R: 0.949, CI (0.794, 0.988) P &lt; 0.001, and mean flow R: 0.955, P &lt; 0.001, CI (0.816, 0.989). There was a significant strong correlation with Pmus and the maximum pressure R: 0.972, P &lt; 0.001, CI (0.883, 0.993) and mean pressure R: 0.942, P &lt; 0.001, CI (0.768, 0.986). There was significant strong correlation between the simulator and the ventilator flow R: 0.961, P &lt; 0.001. There was significant strong correlation between the simulator and the ventilator mean pressure R: 0.951, P &lt; 0.001, CI (0.799, 0.988). There was significant strong correlation between the mean flow from the ventilator to the mean airway pressure measured at the simulator R: 0.936, P &lt; 0.001 CI (0.747, 0.985). Conclusion Results suggest a significant correlation between the flow and pressure from adaptive HFOT and the patient muscle effort, indicating that the flow and pressure increase in response to the patients’ effort. This may reduce respiratory muscle workload compared to traditional high flow oxygen therapies and reduce the need for multiple manual adjustment of the flow. These findings underscore the potential of this technology to enhance respiratory support while minimizing patient effort. Further research is warranted to validate these findings in real patient cohorts in diverse clinical scenarios. Keywords: High flow oxygen therapy, mean flow, mean pressure

Study on Trajectory Optimization for a Flexible Parallel Robot in Tomato Packaging

Currently, flexible robots, exemplified by parallel robots, play a crucial role in the automated packaging of agricultural products due to their rapid, accurate, and stable characteristics. This research systematically explores trajectory planning strategies for parallel robots in the high-speed tomato-grabbing process. Kinematic analysis of the parallel robot was conducted using geometric methods, deriving the coordinates of each joint at various postures, resulting in a kinematic forward solution model and corresponding equations, which were verified with data. To address the drawbacks of the point-to-point “portal” trajectory in tomato grabbing, a 3-5-5-3 polynomial interpolation method in joint space was proposed to optimize the path, enhancing trajectory smoothness. To improve the efficiency of the tomato packaging process, a hybrid algorithm combining particle swarm optimization (PSO) and genetic algorithms (GA) was developed to optimize the operation time of the parallel robot. Compared to traditional PSO, the proposed algorithm exhibits better global convergence and is less likely to fall into local optima, thereby ensuring a smoother and more efficient path in the robot-grabbing tomato process and providing technical support for automated tomato packaging.

A Nonlinear Time Series Analysis on the Effect of Foot Injury on Gait Dynamics

The effects of foot injuries regarding bilateral asymmetry and gait dynamics are still poorly understood. Previous work discussed rehabilitation, postural control, and asymmetry, with the models being mainly validated for upper body translations and no or minimal assessment on rotation. The aim of this study was to assess the effect of foot injury on gait dynamics. For this, a wearable sensors system for data collection of the key variables of the of human movement was considered. The dynamics of motion – recorded in the plane of motion using a laser sensor – was assessed using a new projective method which considers the axial rotations, translation, and in-plane rotation patterns for normal human gait vs. simulated gait pathologies. A nonlinear timeseries analysis, along with a Poincare map, phase space, time delay, Lyapunov exponents, and false nearest neighbors (FNN) method have been considered in order to convey the periodicity of the data collected for a healthy individual with and without a simulated injury. The Lyapunov exponents which quantity the degree of separation of nearby trajectories are used to differentiate between the chaotic and non-chaotic behavior. The positive sign of the largest Lyapunov exponents for all data indicated “the exponential separation of nearby trajectories as time evolves”, that is, the chaotic behavior of the system.

Heritage of empty spaces. The case of the tomb of the unknown soldier in Warsaw

ABSTRACT The study focuses on the Tomb of the Unknown Soldier at Marshall Józef Piłsudski Square in Warsaw and its future in light of the planned reconstruction of the Saxon Palace. By examining the existing memorial – the last World War II ruin in Warsaw and the only remaining part of the former palace – this study conceptualises the heritage value of emptiness. Engaging with ongoing discussions on heritage values within critical heritage studies, it employs the heritage space method to analyse the topography of Piłsudski Square. This highly politicised space, along with the Tomb of the Unknown Soldier and the proposed Saxon Palace reconstruction, is examined through the lenses of authorised heritage discourse and difficult heritage. This paper argues that preserving the empty space serves as a more poignant monument to past (traumatic) events and a more productive response to future challenges than a costly and much-belated post-war reconstruction.

Development of a Cable Assessment Method Based on Phase Space Trajectory for Cable-Stayed Bridge Under Moving Loads

This study emphasized the importance of structural health monitoring for assessing cable-stayed bridges, which are vulnerable to damage, particularly fatigue and corrosion in their cables. Cable tension has been evaluated using natural frequency analysis and a widely adopted vibration-based approach. These conventional methods often required traffic disruptions or even completed bridge closures. This paper proposed a damage detection method for cable-stayed bridge cables under moving loads at low speeds, which minimizes traffic disruptions. This research focused on the phase space method and deck displacement responses in the time domain. A benchmark cable-stayed bridge with a concrete deck and pylon was studied. Seventeen damage scenarios were defined, and two damage indices, change in phase space topology and Mahalanobis distance, were used to detect cable damage. The effectiveness of the phase space-based method for damage detection was validated on two steel cable-stayed bridges with different configurations. The results demonstrated that changes in phase space topology were highly effective at detecting one or two damaged cables. This method required only displacement data at cable-deck connection points, eliminating the need for sensors along the entire deck. This damage detection approach faced challenges with back-stay cables and cables near the pylons.

Surveying space debris management methods: Revealing essential requirements for effective solutions

This paper delves into the management of space debris covering two main categories; preventive measures to mitigate space debris generation and methods for debris removal. Through a thorough review, it clarifies key aspects of outer space governance and the critical importance of effective space debris management. Space debris management methods are categorized into three main groups: prevention of debris generation, repair techniques, and collective/removal methods. Each category employs distinct approaches, which are discussed through its relevant equations and requirements. To define the requirements, two symbol spacecraft with masses of 25 and 100 kg in orbits at altitudes of 600 and 800 km are considered. This analysis aids in the selection of the most effective space debris management method for future space activities.

Note on WAdS3 black holes in extended BHT gravity

In this letter, we study a holographic diffeomorphism invariant higher-derivative extension of Bergshoeff-Hohm-Townsend (BHT) cosmological gravity in the context of Wald's formalism. We calculate the entropy, mass and angular momentum of warped anti-de Sitter (WAdS3) black holes in ghost-free BHT massive gravity and its extension using the covariant phase space method. We also compute the central charges of the dual boundary conformal field theories (CFT) from the thermodynamics method.

Optimal control of the gradient systems

In this paper we consider the optimal control problems governed by the gradient systems for the Ginzburg-Landau free energy where denotes a potential function and ε is the diffusivity. One example of gradient systems are the Schlögl equation arising in chemical waves with a quartic potential function F(y). Gradient systems are characterized by energy decreasing property . Numerical integrators that preserve the energy decreasing property in the discrete setting are called energy or gradient stable. It is known that the implicit Euler method is first order unconditionally energy stable method. The only second order unconditionally energy stable method is the average vector field (AVF) method. We discretize the gradients systems by discontinuous Galerkin method in space and by AVF integrator in time. We solve optimal control problems for the Schlögl equation with traveling and spiraling waves using sparse and regularized controls .

Extended Operational Space Kinematics, Dynamics, and Control of Redundant Serial Robots

A recently developed differential geometric representation of redundant serial robot kinematics is employed to create a new extended operational space dynamics and control formulation that explicitly accounts for redundant robot degrees of freedom. This formulation corrects deficiencies in kinematics and dynamics of redundant serial robots that have relied for over half a century on error-prone generalized inverse velocity-based kinematics for redundancy resolution. New ordinary differential equations of robot operational space dynamics are obtained, without the need for ad hoc derivation, in terms of task coordinates and self-motion coordinates that represent robot redundancy. A new extended operational space control approach is presented that exploits ordinary differential equations of motion in terms of task and self-motion coordinates, enabling enforcement of desired output trajectories, obstacle avoidance, and performance constraints. Four examples are presented with a one-degree-of-redundancy robot that demonstrate the validity and superior performance of the new formulation, relative to the traditional task space method used for redundant serial robot control. Finally, an example with eight degrees of redundancy is presented that further illustrates superior performance of the new operational space formulation.

Galerkin Finite Element Method for Caputo–Hadamard Time-Space Fractional Diffusion Equation

In this paper, we study the Caputo–Hadamard time-space fractional diffusion equation, where the Caputo derivative is defined in the temporal direction and the Hadamard derivative is defined in the spatial direction separately. We first use the Laplace transform and the modified Fourier transform to study the analytical solution of the Cauchy problem. Then, using the Galerkin finite element method in space, we generate a semi-discrete scheme and study the convergence analysis. Furthermore, using the L1 scheme of the Caputo derivative in time, we construct a fully discrete scheme and then discuss the stability and error estimation in detail. Finally, the numerical experiments are displaced to verify the theoretical results.

A path planning method in three-dimensional complex space based on Bézier curves and a hybrid zebra optimization algorithm

A path planning method in three-dimensional complex space based on Bézier curves and a hybrid zebra optimization algorithm

Accurate Flashover assessment for coastal overhead lines based on volt-time criterion

This study investigates the impact of considering insulation volt-time curves on estimating the annual flashover rate of overhead lines subjected to nearby lightning strikes in the presence of ocean-land environments. A method based on the 3D Finite Element Method is employed to compute induced voltages, while a Monte Carlo simulation determines the annual flashover occurrence. To detect Flashover occurrence a volt-time method is employed and the results are compared with the conventional 1.5CFO criterion. The influence of line proximity to the coastline, pole spacing, and various striking distance calculation methods on flashover predictions is evaluated. Results indicate that the 1.5CFO criterion underestimates the annual flashover rate due to indirect lightning in mixed ocean-land terrains compared to the volt-time curve approach. A novel analytical formula is proposed to estimate annual flashovers considering volt-time curves in such environments.