Planar Space Research Articles

An Integrated Kinematic Mapping and Fourier Method to Design Spherical Coupled Serial Chain Mechanisms for Single-Joint Rehabilitation

Abstract Robotic devices are capable of reducing the physical burden on rehabilitation therapists and providing training programs of good repeatability, high efficiency, and high precision. When designing the kinematic structure for rehabilitation robots, there has been a growing interest toward one-degree-of-freedom (DOF) end-effector mechanisms due to their simpler structure and less complicated control algorithms. Compared with current one-DOF mechanism designs that are mainly customized for multi-joint robotic training, spherical coupled serial chain (SCSC) mechanisms are proposed in this paper to specifically deliver the single-joint robotic training, which is of equal importance to the effective physical recovery. Using kinematic mapping theory, the end-effector motion of SCSC mechanisms can be naturally transformed to two trigonometric curves composed of finite Fourier series in two separate planes of the image space. This novel formulation helps to establish an analytical and direct relationship between the design parameters of the SCSC mechanism and the harmonic parameters of the image-space representation of the task rehabilitation motion. The result is a simple and effective method for kinematic synthesis of SCSC mechanisms for generation of single-joint motion with an arbitrary number of spherical poses. An example of designing SCSC mechanisms for shoulder-joint rehabilitation is presented at the end of this paper to illustrate the feasibility of the proposed method.

Low-Light Image Enhancement Method Using a Modified Gamma Transform and Gamma Filtering-Based Histogram Specification for Convex Combination Coefficients

Recently, a lot of low-light image enhancement methods have been proposed. However, these methods have some problems such as causing fine details lost in bright regions and/or unnatural color tones. In this paper, we propose a new low-light image enhancement method to cope with these problems. In the proposed method, a pixel is represented by a convex combination of white, black, and pure color. Then, an equi-hue plane in RGB color space is represented as a triangle whose vertices correspond to white, black, and pure color. The visibility of low-light image is improved by applying a modified gamma transform to the combination coefficients on an equi-hue plane in RGB color space. The contrast of the image is enhanced by the histogram specification method using the histogram smoothed by a filter with a kernel determined based on a gamma distribution. In the experiments, the effectiveness of the proposed method is verified by the comparison with the state-of-the-art low-light image enhancement methods.

Planar Spaces with Projective Connections

Planar Spaces with Projective Connections

Correlation of the apparent diffusion coefficient with the standardized uptake value in meningioma of the skull plane using [68]Ga-DOTATOC PET/MRI.

To evaluate a correlation between an MRI-specific marker for cellular density [apparent diffusion coefficient (ADC)] and the expression of Somatostatin Receptors (SSTR) in patients with meningioma of the skull plane and orbital space. 68 Ga-DOTATOC PET/MR imaging was performed in 60 Patients with suspected or diagnosed meningiomas of the skull base and eye socket. Analysis of ADC values succeeded in 32 patients. ADC values (ADC mean and ADC min ) were analyzed using a polygonal region of interest. Tracer-uptake of target lesions was assessed according to corresponding maximal (SUV max ) and mean (SUV mean ) values. Correlations between assessed parameters were evaluated using the Pearson correlation coefficient. One out of 32 patients (3%) was diagnosed with lymphoma by histopathological examination and therefore excluded from further analysis. Median ADC mean amounted to 822 × 10 -5 mm²/s -1 (95% CI: 570-1497) and median ADC min was 493 × 10 -5 mm 2 /s -1 (95% CI: 162-783). There were no significant correlations between SUV max and ADC min (r = 0.60; P = 0.76) or ADC mean (r = -0.52; P = 0.79), respectively. However, Pearson's test showed a weak, inverse but insignificant correlation between ADC mean and SUV mean (r = -0.33; P = 0.07). The presented data displays no relevant correlations between increased SSTR expression and cellularity in patients with meningioma of the skull base. SSTR-PET and DWI thus may offer complementary information on tumor characteristics of meningioma.

Characterizing orthodontic tooth movement in real time using dental monitoring scans: A pilot study.

This pilot study aimed to quantify the magnitude and type of tooth movement occurring in short time intervals within the regular monthly orthodontic visits for patients with fixed appliances and undergoing maxillary canine retraction. Additionally, this pilot study aimed to provide a descriptive evaluation for the accuracy and reliability of the Dental Monitoring (DM)-captured scans to those of an iTero digital scans in an extraction space closure model. 3D intraoral photographic scans (DM) for 12 patients with maxillary first premolar extractions in a single-centre academic institution. Twelve patients treated with fixed appliances and undergoing space closure for maxillary premolar extraction(s) were included. Nickel-titanium (200 g) closing coil springs were used for canine retraction. At initiation of space closure (T1), iTero scans were acquired, and patients were instructed to take DM scans every 4-5 days until their next visit in 4-5 weeks (T2). At T2, a final iTero scan in addition to a DM scan was taken. The number of patients who did the scans regularly as instructed declined as time elapsed. Stereolithography (STL) files generated from the DM scans were superimposed with the STL files from the iTero scans using GOM Inspect software to determine the accuracy of the DM 3D models. To assess rate, type and direction of tooth movement, each of the 3D image STL files generated from the DM scans, taken every 4-5 days by each patient, was superimposed on the previously captured scan. The rate of tooth movement for the maxillary molars and canines was calculated in the 3 planes of space (X, Y, Z) at each time point, until the end of the experiment. Preliminary results indicated that the maxillary canines appeared to be displaced the greatest amount in the first 4-5 days with initial distolateral movement. As time elapsed, the rate of tooth movement decreased, and the tooth started moving distolingually. Dental monitoring software provides a high-tech platform to monitor tooth movement in a 'real-time' approach. Accuracy of the photographic scans in relationship to the intraoral scans appears promising. There seems to be some evidence that the greatest amount of movement occurs initially in the first few days after activation, dropping thereafter to become a slower constant rate of tooth movement.

The Mastoid Crevasse and 3-Dimensional Considerations in Deep Plane Neck Lifting.

Advances in face and neck lifting involve release of tethering points along the superficial musculoaponeurotic system-platysma complex to freely manipulate the deep natural glide plane in the face and neck. The aim of this article was to determine a combination of deep plane techniques for addressing the face and neck and to elucidate, for the first time, a measurable endpoint for the gonial angle. Analysis of deep plane tethering and decussation zones was also undertaken. Extended deep plane surgery performed in 79 patients (158 hemifaces; age, 30-75 years; 95% female), over a 3-month period, was reviewed. Patients were followed for 1 year. Measurements were performed systematically during deep plane face and neck lifting. Before intervention, the mean [standard deviation] gonial depth was 9.4 [3.6] mm on the left and 8.3 [2.7] mm on the right. The mean depth created below the gonial angle when measuring the traditional suspension to the anterior mastoid was 15.8 [3.3] mm on the left and 13.7 [2.5] mm on the right. The distance postoperatively when measuring the gonial depth after performing the crevasse technique was 23.2 [2.2] mm on the left and 22.5 [2.5] mm on the right. This represents a mean increase in the advancement of 7.4 mm on the left and 8.8 mm on the right (average, 8.1 mm) which was demonstrated to be statistically significant bilaterally (P < .0001). The deep plane techniques described here aid manipulation of the deep plane and deep neck space, while also providing measurable endpoints and more effective modes of fixation by utilizing the mastoid crevasse. The use of techniques that release tension and allow redrape produce the most natural and well-balanced results.

The Ie-Re plane and the 3D-kappa space of stellar systems

Contact. This paper is the fourth in a series dedicated to the observed parallelism of properties passing from globular clusters to early-type galaxies. To a lesser extent, it also covers galaxy clusters and groups. Aims. Here, we investigate the Ie-Re plane and the 3D-kappa space defined by Bender, Burstein and Faber, as potential diagnostic tools in studies of the past evolution of these stellar systems. In the space of the parameters characterizing a stellar system such as the luminosity, L, stellar mass, Ms, half-light (mass) radius, Re, central velocity dispersion, σc, surface brightness, Ie, and so on, the Ie-Re plane is one of possible projections that was thoroughly investigated over the years with many important results. The 3D-kappa space relies on three variables that are suitable combinations of the logarithms of the above parameters. Among others, perhaps the most important result from this new space is the discovery of the fundamental plane of early type galaxies. In this paper, we intend to explore in more detail the potential capability of the joined investigation of the Ie-Re plane and 3D-kappa space. Methods. Based on the collected literature data on the mass, half-mass (light) radius, velocity dispersion, and surface brightness in different bands for the objects under investigation, we set up the Ie-Re plane and the 3D-kappa space. We then compared the observed distributions of these objects with those predicted by simple theoretical galaxy models. Results. We explored the effects of different mass-radius relationships, star formation, infall, and mass assembling histories on the diagnostic planes under examination. We also investigated variations in the 3D-kappa space as a function of the redshift. Conclusions. We show that the distribution of the stellar systems on the various diagnostic planes can cast light on the mass-radius relation and the history of star formation in stellar systems going from globular clusters to early type galaxies.

Major deleterious oral habits: a brief systematic review

Introduction: The deleterious habits in children, in the deciduous dentition phase, seem to be present in more than half of the child population, reaching rates greater than 90%, depending on the population studied, and dentofacial alterations may already be present in half of these individuals. Early identification is essential so that malocclusions, which are more difficult to treat, do not set in. Objective: It was to carry out a brief systematic review to highlight deleterious oral habits, as well as to point out their main predictors and treatments. Methods: The systematic review rules of the PRISMA Platform were followed. The research was carried out from April to June 2023 in Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 87 articles were found. A total of 32 articles were evaluated in full and 16 were included and developed in this systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 6 studies with a high risk of bias and 43 studies that did not meet GRADE. Since pediatric follow-up is more frequent than consultations with the pediatric dentist, the early identification of deleterious habits by physicians is of fundamental importance in referring these patients to dental treatment that diagnoses and removes these habits, before difficult-to-resolve malocclusions get settled. Preventive measures should also be taken, guiding parents so that deleterious oral habits do not take hold, such as a minimum period of six months of breastfeeding, finger sucking should be replaced by an orthodontic pacifier, the bottle should have an orthodontic spout, removing the habit of pacifier and bottle until the age of three. There is an association between deleterious habits and different types of malocclusions in different planes of space, with atypical swallowing being a habit that must be diagnosed early.

Anatomy of the Facial Glideplanes, Deep Plane Spaces, and Ligaments: Implications for Surgical and Nonsurgical Lifting Procedures.

The soft-tissue glideplanes of the face are functionally important and have a role in facial rejuvenation surgery. The aim of this study was to improve understanding of soft-tissue mobility of the face and its effect on the redraping of tissues involved in face lifting. The consequences of no-release and extensive-release lifting were analyzed to explain the difference in efficacy and potential longevity between these 2 contrasting philosophies. Preliminary dissections and macrosectioning were followed by a definitive series of standardized layered dissections on 50 cadaver heads, along with histologic analysis, sheet plastination, and mechanical testing. The previously described spaces are potential surgical dissection planes deep to the superficial fascia layer. The classically described retaining ligaments are local reinforcements of a system of small retaining fibers (retinacula cutis and deep retinacula fibers) that provide support to the soft tissues of the face and neck against gravitational sagging while allowing certain mobility. This mobility is used when mobile tissues are lifted without surgical release. However, the process of dragging up these fibers results in a loss of their previous antigravitational, supportive orientation. No-release lifting techniques, such as thread lifts and minimal-invasive face lifts, tighten tissue laxity with a change of the gravity-opposing tissue architecture, placing the weight of the flap solely on the fixation, which limits longevity of the lift. The alternative-full release with redraping-enables reattachment of the flap to a higher position, with preservation of the original deep fascial architecture with its antigravity orientation and natural mobility, conceivably improving the longevity of the lift.

Ces\`{a}ro-Type Operator on the Dirichlet Space of the Upper Half Plane

We construct a Ces\`{a}ro-type operator acting on Dirichlet space of the upper half plane using the approach of strongly continuous semigroups of composition operators on Banach spaces. We then determine the spectral and norm properties of the obtained Ces\`{a}ro-type operator.

Investigation of Natural Weak Interface Properties and Their Impact on Fracture Propagation in Shale Reservoirs

Horizontal well multi-cluster fracturing technology is crucial for the economic development of fractured shale reservoirs. The abundance of natural fractures in shale reservoirs significantly influences the propagation path of hydraulic fractures and determines the formation of complex fracture networks. To investigate the impact of natural weak planes on the geometric parameters of fractures in shale reservoirs, we first conducted tests on the mechanical characteristics of core samples from outcropping shale in the Weiyuan area using the indoor three-point bending method and digital image correlation (DIC) technology, providing data validation for subsequent numerical models. Secondly, considering the interaction between hydraulic and natural weak planes in three-dimensional space, we established a three-dimensional numerical model for horizontal well fracturing to simulate the synchronous competition and expansion of fractures in multi-cluster fracturing. Based on this foundation, we analyzed the influence of formation parameters and engineering parameters on the formation patterns of complex fracture networks. The results indicate that the difference in in situ stress is a significant factor affecting the selection of fracture propagation paths. As the in situ stress difference increases, it becomes more challenging to open natural fractures, leading to a reduced probability of activation of natural weak interfaces. When the cohesive strength of natural fractures is smaller, they are more likely to open and capture hydraulic fractures, thereby increasing shear slip length and fracture network area. Each fracturing stage has an optimal perforation density combination, where a higher density of perforations leads to reduced perforation pressure drop and weaker ability to mitigate inter-cluster stress interference. To achieve a comprehensive and balanced development of multi-clusters, the inter-cluster stress interference can be alleviated by increasing the perforation pressure drop. For dense perforation clusters, higher injection rates and viscosity can be employed to ensure the uniform development of multiple perforation clusters. This study provides new insights into predicting the formation of complex fracture networks in shale reservoirs and offers valuable guidance for optimizing hydraulic fracturing designs.

Gait variability of interlimb coordination in high-heeled shoes with detachable base sockets under conditions of sinusoidal speed change

BackgroundThis study aimed to investigate the effects of wearing high-heeled shoes (HHS) on gait variability of the lower limbs when the treadmill speed was sinusoidally changed. MethodsA total of 17 young females walked on a treadmill with HHS, HHS with detachable base sockets (HHS-Sockets), and low-heeled shoes (LHS) under sinusoidal speed-changing protocol of 60-s and 30-s periods with an amplitude of ± 0.56 m·s-1. The time course of the joint elevation angles of the thigh, shank, and foot in one gait cycle can be well approximated like a plane in a triaxial space, so-called intersegmental coordination (IC). Standard deviation of the plane (IC thickness) was considered as the anteroposterior gait variability when the best-fitting plane of the angular covariation was obtained. The lateral gait variability was the coefficient of variance of step width (CVSW). To examine whether the gait parameters was associated with IC thickness, a sum of the time delay of the stride length and step frequency (TDSL+SF) against sinusoidal speed change was calculated. ResultsThe IC thickness was not different across shoe conditions and periods. The CVSW was greater in the HHS and HHS-Sockets conditions than in the LHS condition. TDSL+SF was greater in the HHS condition than in the LHS and HHS-Sockets conditions at both periods; however, it was not correlated with IC thickness. SignificanceWalking with HHS increased lateral gait variability at faster speed-changing situation, but not anteroposterior gait variability. Detachable sockets expanding the base area ten times greater than that of HHS could reduce TDSL+SF; however, TDSL+SF could not explain the IC thickness.

Computed tomography evaluation of alterations in the masticator space due to invasion by malignant head and neck neoplasms.

To evaluate alterations in the masticator space due to the dissemination of malignant neoplasms originating from the tonsillar fossa, retromolar trigone, maxillary sinus, or nasopharynx, using computed tomography (CT), as well as to correlate the presence of trismus with the CT findings and the dimensions of the tumor. We evaluated the medical records of 65 patients with malignant tumors in the regions described. The images were analyzed by two physician examiners, working independently, who were blinded to the clinical data. In the evaluation of the masticator space, the following parameters were considered: symmetry with the contralateral space; obliteration of the fat plane, retromolar trigone, or pharyngeal space; edema/atrophy of the medial or lateral pterygoid muscles; and destruction of the mandibular ramus. Obliteration of the fat plane was found in 69.2% of the patients. Asymmetry, edema/atrophy, and bone destruction were detected in 27.7%, 26.2%, and 20.0% of the patients, respectively. Trismus was identified in 15.4% of the patients. Of the patients with trismus, 90.0% had stage T4 tumors, compared with only 43.8% of those without trismus. Trismus was 11.6 times more common among the patients with stage T4 tumors than among those with lower-stage tumors. Neoplasms of the tonsillar fossa and retromolar trigone collectively accounted for 95.0% of the cases. The CT scans showed edema/atrophy of the pterygoid muscles in 60.0% of the patients with trismus and in 21.8% of those without. An association was observed between T4 tumor stage and edema/atrophy of the pterygoid muscles. In addition, the risk of trismus was 5.4 times higher among the patients with stage T4 tumors. In our patient sample, the most common finding was obliteration of the fat plane, followed by asymmetry and edema/atrophy. Most of the patients with T4 tumors had trismus, together with edema/atrophy of the pterygoid muscles.

Approximated unsharp masking on equi-hue plane in RGB color space

Approximated unsharp masking on equi-hue plane in RGB color space

The key technology of 3D seismic data contiguous processing and its application: Taking the northern slope area of Zhahaquan in Qaidam Basin as an example

The surface conditions in the northern slope area of Zhahaquan in the Qaidam Basin are complex, and the underground is affected by tectonic extrusion movements, resulting in the development of faults and fractures. The existing six blocks of 3D seismic data in this area have a significant time span in acquisition and varying data quality. The existing single-block processing results indicate a low signal-to-noise ratio in the 3D seismic data connection area, along with substantial differences infrequency, phase, and energy. The fracture imaging is poor, making it challenging to accurately identify and track layer positions and fault planes in space, thereby restricting further exploration in this region. Based on a detailed analysis of the characteristics and existing problems of the original data, we conducted key technical research on continuous static correction, pre-stack noise purification, consistency processing, data regularization, and anisotropic pre-stack time migration for continuous processing of six blocks of 3D seismic data in this area. The processing results demonstrate good consistency in frequency, phase, energy, and other aspects, highlighting prominent reflection characteristics and clear imaging of complex structures in the middle and deep layers. Clear breakpoints and fault planes are also evident, solving the inconsistency of frequency, phase, energy, and incomplete coverage in the block connection section. Additionally, this processing has resolved the problem of inaccurate migration positioning caused by inconsistent migration velocity fields, providing high-quality data for subsequent structural interpretation and reservoir prediction.

A Gaussian kernel for Kendall’s space of [formula omitted]-D shapes

In this paper, we develop an approach to exploit kernel methods with data lying on the m-D Kendall shape space. When data arise in a finite-dimensional curved Riemannian manifold, as in this case, the usual Euclidean computer vision and machine learning algorithms must be treated carefully. A good approach is to use positive definite kernels on manifolds to embed the manifold with its corresponding metric in a high-dimensional reproducing kernel Hilbert space, where it is possible to utilize algorithms developed for linear spaces. Different Gaussian kernels can be found in the literature on the 2-D Kendall shape space to perform this embedding. The main novelty of this work is to provide a Gaussian kernel for the m-D Kendall shape space. This new Kernel coincides in the case m=2 with the Gaussian kernels most widely used in the Kendall planar shape space and allows to define an embedding of the m-D Kendall shape space into a reproducible kernel Hilbert space. As far as we know, the complexity of the m-D Kendall shape space has meant that this embedding has not been addressed in the literature until now. This methodology will be tested on a machine learning problem with a simulated and a real data set.

Intermittent State Observer Design for Neural Networks With Reaction–Diffusion Terms Using Partial Measurements

This article develops a novel state observer for delayed reaction–diffusion neural networks by utilizing incomplete measurements. To reduce the transmission cost efficiently, the space domain is divided into <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$L$</tex-math> </inline-formula> parts and only partial information needs to be measured in every subdomain, such as a point in one-dimensional space, a line and a plane in two-and three-dimensional space, respectively. In addition, the time domain is divided: the measured output signals are transmitted intermittently. Then, new conditions that assure the asymptotic stability of observation error system are derived based on the Lyapunov direct method and several inequality techniques. Finally, the proposed approach’s effectiveness is demonstrated via three numerical examples.

Prevalence of malocclusion in Turkish children and adolescents: A systematic review and meta-analysis.

The aim of this article is to establish a comprehensive nationwide prevalence of malocclusion traits on the sagittal, vertical, and transverse planes of space in the Turkish population. A systematic search of PubMed, Scopus, and Web of Science was supplemented by manual searches of Google Scholar and the reference lists of included studies. Original Turkish health studies of any age were included. Strengthening the Reporting of Observational Studies in Epidemiology assessed study quality and bias (STROBE). Sagittal, vertical, and transverse malocclusion features were retrieved and gathered. Elevenstudies were selected from 434 titles. Two studies showeda high risk of bias, eight lowand one moderate. Thirteen thousand two hundred seventy-one individuals were investigated from early childhood to late adulthood. Most studies were sampled from universities and dental (nonorthodontic) clinics. The pooled malocclusion prevalence was 56% for Class I (95% confidence interval (CI): 44-68%), 31% for Class II (CI: 6-42%), and 11% for Class III (CI: 21-37%). The other common types of malocclusions were crowding (41%, CI: 18-65%), overjet (34%, CI: 21-50%), negative overjet (13%, CI: 7-20%), and crossbite (11%, CI: 7-15%). Additionally, there was no significant difference in Class I (relative risk [RR] = 1.00, [0.96-1.05]), Class II ([RR] = 0.97, [0.92-1.03]), and Class III ([RR] = 1.08, [0.96-1.225]) malocclusion by gender. This study showed Class I malocclusion has a high prevalence among the Turkish population followed by Class II and Class III malocclusions. In addition, crowding and overjet were the most prevalent malocclusions among Turkish individuals. There were no significant differences in the prevalence of malocclusions between males and females.

Concordance and reproducibility in the location of reference points for a volumetric craniofacial analysis: Cross-sectional study.

Considering the limitations of visualization that occur even with the use of radiographs, the cone beam computed tomography (CBCT) becomes more attractive to diagnose and propose an assertive treatment plan. This study aimed to evaluate intra and interobserver reproducibility, and concordance of 31 reference points we described considering visualization tools and the three planes of space in a bimaxillary CBCT. Three observers located in triplicate the 31 reference points in the CBCT of six healthy patients. Friedman test was used to compare intraobserver paired samples, and interobserver concordance was determined by the intraclass correlation coefficient (ICC) with ranges>0.75 (excellent), between 0.60 and 0.74 (good), between 0.40 and 0.59 (sufficient) and<0.40 (poor). The P value was set at<0.05. A high ICC (>0.75%) was obtained by comparing the x, y, and z values at the location of landmark points. Excellent ICC>0.75 was for 81.7% and poor<0.40 was 7.5% in the interobserver evaluation. Data showed that 25 points had excellent concordance on the x-plane, 25 on the y-plane, and 26 on the z-plane (0.75%). Intraobserver concordance analysis indicated that location of anatomical reference points on bimaxillary CBCT is performed with great reproducibility by interpreting their location with a clear description in the three planes of space. Complexity of achieving a good precision degree in the manual marking of reference points caused by convexities of the anatomical structures involved, might explain the variability found. The systematized location of the reference points would contribute to reduce such variability.

Retracted: Construction and Analysis of Urban Cultural Plane Space Mode considering Particle Swarm Cultural Scientific Computing Algorithm

Retracted: Construction and Analysis of Urban Cultural Plane Space Mode considering Particle Swarm Cultural Scientific Computing Algorithm