Spatial Plane Research Articles

Reconstruction of the interosseous talocalcaneal ligament using allograft for subtalar joint stabilization is effective

PurposeThe aim of this study was to assess the biomechanical effects of subtalar ligament injury and reconstruction on stability of the subtalar joint in all three spatial planes.MethodsFifteen fresh frozen cadaveric legs were used, with transfixed tibiotalar joints to isolate motion to the subtalar joint. An arthrometer fixed to the lateral aspect of the calcaneus measured angular displacement in all three spatial planes on the inversion and eversion stress tests. Stress manoeuvres were tested with the intact joint, and then repeated after sequentially sectioning the inferior extensor retinaculum (IER), cervical ligament (CL), interosseous talocalcaneal ligament (ITCL), arthroscopic graft reconstruction of the ITCL, and sectioning of the calcaneo-fibular ligament (CFL).ResultsSectioning the ITCL significantly increased angular displacement upon inversion and eversion in the coronal and sagittal planes. Reconstruction of the ITCL significantly improved angular stability against eversion in the axial and sagittal planes, and against inversion in the axial and coronal planes, at the zero time point after reconstruction. After sectioning the CFL, resistance to eversion decreased significantly in all three planes.ConclusionProgressive injury of ligamentous stabilisers, particularly the ITCL, led to increasing angular displacement of the subtalar joint measured with the inversion and eversion stress tests, used in clinical practice. Reconstruction of the ITCL using tendon graft significantly stabilised the subtalar joint in the axial and sagittal planes against eversion and in the axial and coronal planes against inversion, immediately after surgery.

The Plumb-Line Matching Algorithm for UAV Oblique Photographic Photos

Building facades has always been a challenge for feature matching in oblique photogrammetry due to weak textures, non-Lambertian objects, severe occlusion, and distortion. Plumb lines are essential building geometry structural feature lines in building facades, which show strong spatial relevance to these problems. Achieving plumb line matching has great application potential for optimizing the process and products of oblique photogrammetry. Thus, we proposed a novel matching algorithm for plumb lines based on spatial and color hybrid constraints according to its central projection imaging characteristics. Firstly, based on vanishing point theory, the plumb lines from photos were back-calculated to determine the matching target set; secondly, the property of its large elevation ranges was exploited to calculate the homonymous points as spatial constraints by projecting plumb lines onto the stratified spatial planes; thirdly, the neighboring primary colors on both sides of the plumb lines were extracted as feature descriptors and compared by colorimetry; then, the greedy strategy was employed to successively filter out the locally optimal solutions satisfying the spatial and color hybrid constraints to complete the initial matching; finally, the intersection-over-union analysis of the solution plane and the verticalness evaluation of the matching results were implemented to eliminate errors. The results show that the proposed algorithm can achieve an average accuracy of 97.29% and 78.41% in the forward and lateral overlap experiments from multi-scenes, respectively, displaying a strong adaptability to poor texture, inconsistency, and distortion. In conclusion, thanks to the plumb-line-oriented matching strategy, this algorithm owns inherent advantages in theory and computational complexity. It is suitable for all building-oriented oblique photogrammetry tasks and is highly worthy of promotion and application.

Vertex algebra of extended operators in 4d N=2 superconformal field theories. Part I

We construct a class of extended operators in the cohomology of a pair of twisted Schur supercharges of 4d mathcal{N} =2 SCFTs. The extended operators are constructed from the local operators in this cohomology — the Schur operators — by a version of topological descent. They are line, surface, and domain wall world volume integrals of certain super descendants of Schur operators. Their world volumes extend in directions transverse to a spatial plane in Minkowski space-time. As operators in the cohomology of these twisted Schur supercharges, their correlators are (locally) meromorphic functions only of the positions where they intersect this plane. This implies the extended operators enlarge the vertex operator algebra of the Schur operators. We illustrate this enlarged vertex algebra by computing some extended-operator product expansions within a subalgebra of it for the free hypermultiplet SCFT.

A Novel Two-Phase Approach to Forest Harvesting Optimization Using Cable Logging

Timber extraction is a vital process in forest harvesting, particularly in areas with high slopes where timber harvesting methods are not feasible. In such cases, logging towers employing extraction cables are often the most effective solution. This intricate task involves several phases, with the installation of the tower being one of the most critical. It significantly influences the performance and feasibility of timber extraction. Another crucial phase involves strategically positioning logging lines to minimize the installation time while maximizing the load capacity efficiency. This article presents an integer programming mathematical model for determining the optimal positioning of yarders conditioned to logging lines, the timber logging time, and the logging cycle time. Furthermore, a two-phase heuristic algorithm is introduced to address the problem. Both approaches offer a preliminary proposal for the location of logging towers and the arrangement of logging lines within a two-dimensional spatial plane, thereby streamlining the timber extraction process in challenging terrains. Finally, we compare manually generated approximate planning (referred to as the manual planning approach, MPA) with our presented approaches. Our methods outperform the MPA, and notably, our two-phase approach surpasses solvers commonly used in the industry by up to 38% in real case studies.

Use of speckle tracking echocardiography in evaluating cardiac dysfunction in patients with acromegaly: an update.

In recent years, cardiovascular disease has garnered increasing attention as the second leading cause of death in individuals with acromegaly, following malignancy. Identifying cardiac dysfunction early in acromegaly patients for timely intervention has become a focal point of clinical research. Speckle tracking echocardiography, a well-established ultrasound technique, surpasses conventional Doppler ultrasound in its sensitivity to assess both local and global cardiac mechanics. It can accurately detect subclinical and clinical myocardial dysfunction, including myocardial ischemia, ventricular hypertrophy, and valvular changes. Over the past five years, the use of speckle tracking echocardiography in acromegaly patients has emerged as a novel approach. Throughout the cardiac cycle, speckle tracking echocardiography offers a sensitive evaluation of the global and regional myocardial condition by quantifying the motion of myocardial fibres in distinct segments. It achieves this independently of variations in ultrasound angle and distance, effectively simulating the deformation of individual ventricles across different spatial planes. This approach provides a more accurate description of changes in cardiac strain parameters. Importantly, even in the subclinical stage when ejection fraction remains normal, the strain parameters assessed by speckle tracking echocardiography hold a good predictive value for the risk of cardiovascular death and hospitalization in acromegaly patients with concomitant cardiovascular disease. This information aids in determining the optimal timing for interventional therapy, offering important insights for cardiac risk stratification and prognosis. In the present study, we comprehensively reviewed the research progress of speckle tracking echocardiography in evaluating of cardiac dysfunction in acromegaly patients, to pave the way for early diagnosis of acromegaly cardiomyopathy.

Automated Determination of the Volume of Loose Engineering Deposits Using Terrestrial Laser Scanning

A new method for automatic volume determination of loose engineering deposits (LEDs) using point clouds collected by terrestrial laser scanning is proposed. The method starts with a problem of lacking bottom surface point clouds when scanning LEDs, assuming that the bottom surface is flat, a spatial plane is generated based on the plane fitting to the bottom surface. Then the sample point cloud is projected on this fitted plane to construct the subface point clouds, which, together with the initial point cloud data, are stitched into complete point cloud data with good closure, integrity, and accuracy. The 3D surface model established by introducing the alpha shape algorithm calculates the volume, and the validation experiments on three soil mound models and one field experiment on LEDs with a minimum average error of only 1.69% fully validate the effectiveness and accuracy of the method. The encouraging results show that effective volume calculation can be performed on realistic LEDs using the proposed method.

Integrated spatial planing in the function of sustainable use of natural resources

Sustainable use of natural resources is one of the basic goals of sustainable spatial development, which could be achieved with the use of integrated planning. It includes comprehensive analyzes of all aspects of space in a unique planning methodology, involvement of participatory process, and institutional, financial and legislative support to the system of integrated planning. Integrated planning, due to its complexity and, to a largely extent, dependence on the system of socio-economic and administrative-political organization of the territory, is difficult to achieve in practice, even in developed countries. In the former socialist countries, such as the Republic of Srpska, there are numerous problems that need to be solved, in order to improve planning practices and create systemic preconditions for the implementation of integrated planning. Within this process, this paper also looks at the issue of sustainable use of natural resources in the territory of Republic of Srpska, which significantly participate in the potential of the Republic for sustainable future development. The paper deals in the first part with the theoretical assumptions and principles of sustainable development, through the prism of using natural resources, and then focuses on the methodology of integrated planning, with reference to legislation and planning practice in Republic of Srpska, with recommendations for their improvement.

Micro-CT Evaluation of Centering Ability and Canal Transportation of Protaper Ultimate and RevoS+ Rotary File Systems in Simulated Curved Canals

Purpose
 A successful root canal preparation is to remove infected dentin and pulp tissue and to obturate the canal three-dimensionally. This study aimed to compare the centering ability of Protaper Ultimate and RevoS+ rotary file systems in curved canals of printed mandibular first molars by using micro-computed tomography (micro-CT). 
 Materials and Methods
 In this in-vitro study, 16 mandibular molar teeth were printed from resin with 45° mesial root curvature. Root canal preparation was performed according to the specified groups, either Protaper Ultimate or RevoS+. The pre-and post-preparation images were repositioned in all three spatial planes by DataViewer. All images were imported into the CTAn software for the calculation of the centering ability and transportation values. 
 Results
 The results showed no significant differences between the Protaper Ultimate and RevoS+ groups in terms of the centering ratio in the most inclined part of the canal. There were also no significant differences between the groups in canal transportation. (p>0.05)
 Conclusions
 Protaper Ultimate and RevoS+ rotary file systems showed similar ability in centering ratio and canal transportation in curved canals from printed mandibular molars.

The modification of Mohr-Coulomb criteria based on shape function and determination method of undetermined parameters

Rock strength criteria is a key step to estimate the stability of rock engineering, especially, the effect of intermediate principal stress on rock failure should be considered in formation at great depth. However, the mostly used Mohr-Coulomb criterion don't consider the effect of intermediate principal stress, besides, most rock mechanics laboratories do not have the ability to do true triaxial strength, the strength parameters in poly-axial strength criteria are difficult to be determined. In order to solve these problems, based on the least absolute deviation method, the square of the correlation coefficient, absolute difference and mean difference are adopted to verify the fitting effect of 10 strength criteria on 32 groups of true triaxial strength data. On this basis, the elliptical Lode angle shape function, hyperbolic Lode angle shape function, and the Lode angle shape function based on spatial slip plane are used to establish the modified MC strength criteria, which not only meets the requirements of smoothness and convexness, but also can be used widely in many geomaterials. Besides, strength parameters of the established criteria can be decided by conventional triaxial strength experiment, and the prediction accuracy of the modified MC strength criteria for the 32 groups of true triaxial strength data is better than or close to the lowest fitting error of the existing poly-axial strength criteria.

Authenticity Scaffolding Across Temporal and Spatial Planes: The Scottish Ginaissance

Authenticity Scaffolding Across Temporal and Spatial Planes: The Scottish Ginaissance

Analog of a Laplace–Runge–Lenz vector for particle orbits (time-like geodesics) in Schwarzschild spacetime

In Schwarzschild spacetime, time-like geodesic equations, which define particle orbits, have a well-known formulation as a dynamical system in coordinates adapted to the time-like hypersurface containing the geodesic. For equatorial geodesics, the resulting dynamical system is shown to possess a conserved angular quantity and two conserved temporal quantities, whose properties and physical meaning are analogs of the conserved Laplace–Runge–Lenz vector, and its variant known as Hamilton’s vector, in Newtonian gravity. When a particle orbit is projected into the spatial equatorial plane, the angular quantity yields the coordinate angle at which the orbit has either a turning point (where the radial velocity is zero) or a centripetal point (where the radial acceleration is zero). This is the same property as the angle of the respective Laplace–Runge–Lenz and Hamilton vectors in the plane of motion in Newtonian gravity. The temporal quantities yield the coordinate time and the proper time at which those points are reached on the orbit. In general, for orbits that have a single turning point, the three quantities are globally constant, and for orbits that possess more than one turning point, the temporal quantities are just locally constant as they jump at every successive turning point, while the angular quantity similarly jumps only if an orbit is precessing. This is analogous to the properties of a generalized Laplace–Runge–Lenz vector and generalized Hamilton vector which are known to exist for precessing orbits in post-Newtonian gravity. The angular conserved quantity is used to define a direct analog of these vectors at spatial infinity.

The Effect of Changes in the Angular Position of Implants on Metal Artifact Reduction in Cone-Beam Computed Tomography Images: A Scoping Review.

Dental implant artifacts can compromise the quality of cone-beam computed tomography (CBCT) scans and challenge radiographic detection in surrounding regions. This literature review was conducted to examine the impact of implant angle modification on reducing metal artifacts in CBCT scans. A scoping review of literature was carried out in PubMed, Embase, Scopus, and Cochrane databases. Different spatial planes, including alpha, beta, gamma, and phi, along with 0°, 5.2°, 9.8°, 14.5°, 15°, 30°, 45°, 60°, 75°, and 90° angles were studied. Changes in the angular position of implants may reduce metal artifacts and improve the quality of CBCT scans. Rotating implants within the alpha plane and angling them at 90° in the alpha plane enables reducing dental implant artifacts.

Characterization of Mandibular Border Movements and Mastication in Each Skeletal Class Using 3D Electromagnetic Articulography: A Preliminary Study.

Mandibular movement recording is relevant for the planning and evaluation of mandibular function. These movements can include mandibular border movements (MBM) or mastication. Our objective was to characterize the kinematics of MBM and mastication among skeletal classes I, II, and III in the three spatial planes. A descriptive cross-sectional study was conducted with 30 participants. Instructions were provided on how to form Posselt's envelope and to perform masticatory. After data processing, we obtained numerical values for the areas, trajectories, and ranges of MBM that formed Posselt's envelope and the values for speed, masticatory frequency, and the areas of each masticatory cycle. Significant differences were found in the area of Posselt's envelope in the horizontal plane between skeletal classes I and III and in the range of right laterality between skeletal classes II and III. Mastication showed significant differences in the area of the masticatory cycles in the horizontal plane between classes I and III and between classes II and III. In conclusion, there were differences in MBM and mastication between skeletal classes III and I in the horizontal plane. This study supports the need to establish normal values for mandibular kinematics in skeletal class III.

Image transmission with a circular Airy array beam.

A circular Airy array beam (CAAB) comprising four symmetric circular Airy beams is proposed and demonstrated for image transmission. It is generated by the Fourier transform of the combined phase, which contains the radial cubic phase, the diffractive axicon phase, and the shift function phase. Two adjustable parameters of the combined phase can control the radius and the initial position of each circular Airy beam at the spatial plane. The image can be modulated into the CAAB through overlapping it at the Fourier plane of this beam and recovered by Fourier transform after diffracting a certain distance. It can be observed clearly that the CAAB after being partly blocked by a movable obstacle guarantees the recovery of the image. In comparison with the existing right-angle Airy array beam, the image transmission by the proposed CAAB is less sensitive to the position of the obstacles on the beam path.

Audio for extended realities: A case study informed exposition

An area of immersive storytelling in rapid evolution is that of extended reality. This emergent mode of experience employs spatial mapping, and both plane and object detection to superimpose computer-generated images in the volumetric context of a physical space via a head-mounted display. This in turn produces a unique set of challenges and opportunities for associated audio implementation and aesthetics. Creative development of this audio is often a function of evolving toolsets, and the associated workflow is far from standardized. This paper forms a context for such audio workflow, one that draws from precursor technologies such as audio for games and virtual reality and develops this into an outline taxonomy that is both representative of the state of the art, and forward facing towards evolution of the technology stack. The context is framed through a series of case studies. Between 2019 and 2021, BBC and Oculus TV commissioned Alchemy Immersive and Atlantic Productions to produce virtual reality and mixed reality experiences of several classic documentary series by Sir David Attenborough: Museum Alive, Micro Monsters, First Life VR, Museum Alive AR and Kingdom of Plants. This portfolio received numerous award nominations and prizes, including from the Raindance Festival and a double Emmy. The sound design, audio postproduction and spatial audio for these experiences were implemented by the company 1.618 Digital, and drawing from first-hand-creator involvement, the workflows are deconstructed and explored with reference to tools, technologies, techniques and perception. Such an exposition forms the basis for an analysis of both this and broader creative practice in the field of audio for extended reality, and this is subsequently used to present a speculative vision of audio in the future of immersive storytelling.

Quantification of pharyngeal airway space changes after two-jaw orthognathic surgery in skeletal class III patients

BackgroundSkeletal class III malocclusion is a common dentofacial deformity. Orthognathic treatment changes the position of the jaws and affects the shape of the upper airway to some extent. The aim of this study was to use multislice spiral computer tomography data and orthognathic knowledge to quantify the relationship between the amount of surgical movement of the maxilla or mandible in all three spatial planes and the changes in airway volume that occurred.MethodsA retrospective study of 50 patients was conducted. Preoperative and postoperative linear changes related to skeletal movements of the maxilla and mandible were measured and compared to changes in the most constricted axial level (MCA) and its anteroposterior (MCA-AP) and transverse diameters (MCA-TV). Correlation tests and linear regression analysis were performed.ResultsSignificant interactions were observed between the anterior vertical movement of the maxilla and the MCA-AP. The anteroposterior movement distance of the mandible was significantly correlated with changes in the oropharyngeal, velopharyngeal, total airway volume, MCA, MCA-AP, and MCA-TV. The change in the mandibular plane angle was significantly correlated with the change in velopharyngeal volume, total airway volume (nasopharynx, oropharynx, velopharynx), and MCA.The linear regression model showed that oropharyngeal volume decreased by 350.04 mm3, velopharyngeal volume decreased by 311.50 mm3, total airway volume decreased by 790.46 mm3, MCA decreased by 10.96 mm2 and MCA-AP decreased by 0.73 mm2 when point B was setback by 1 mm.ConclusionsAnteroposterior mandibular control is the key to successful airway management in all patients. This study provides estimates of volume change per millimeter of setback to guide surgeons in treatment planning.

Semantic Plane-Structure based motion detection with a nonstationary camera

This paper presents a novel method to accurately detect moving objects from a video sequence captured using a nonstationary camera. Although common methods provide effective motion detection for static backgrounds or through only planar-perspective transformation, many detection errors occur when the background contains complex dynamic interferences or the camera undergoes unknown motions. To solve this problem, this study proposed a motion detection method that incorporates temporal motion and spatial structure. In the proposed method, first, spatial semantic planes are segmented, and image registration based on stable background planes is applied to overcome the interferences of the foreground and dynamic background. Thus, the estimated dense temporal motion ensures that small moving objects are not missed. Second, motion pixels are mapped on semantic planes, and then, the spatial distribution constraints of motion pixels, regional shapes and plane semantics, which are integrated into a planar structure, are used to minimise false positives. Finally, based on the dense temporal motion and spatial structure, moving objects are accurately detected. The experimental results on CDnet dataset, Pbi dataset, Aeroscapes dataset, and other challenging self-captured videos under difficult conditions, such as fast camera movement, large zoom variation, video jitters, and dynamic background, revealed that the proposed method can remove background movements, dynamic interferences, and marginal noises and can effectively obtain complete moving objects.© 2017 ElsevierInc.Allrightsreserved.

“Russia, Rossia, Rus, Kolomna: Province”: Conceptualization of Space in B. Pylnyak’s Novel “Volga Flows into Caspian Sea”

The principles of structuring and methods of objectification of the spatial continuum in B. Pylnyak’s novel “The Volga flows into the Caspian Sea” are investigated. Particular attention is focused on the lexical representation of space as a basic category of the author’s language picture of the world. The novelty of the research consists in the identification, systematization and description of linguistic material, which allows to determine individual author’s features in the creation of the spatial continuum of B. Pylniak’s novel. The relevance of the article is due to addressing the problem of linguistic expression of world-modeling universals in a literary text. The article uses methods of semantic and linguistic stylistic analysis, comparison and description of language units. It helps us to identify and consider the means of lexical representation of the spatial model created in the novel “Volga Falls into Caspian Sea”, which is characterized by kaleidoscopicity, dynamism and the combination of different spatial planes. During the research, the author comes to conclusions containing the characteristics of the main types of space in B. Pylniak’s novel, taking into account the individual features of the author’s world modeling, as well as the substantiation of the revealed linguistic parameters of the writer’s idiostyle.

Spatial and orbital planes of the Milky Way satellites: unusual but consistent with ΛCDM

ABSTRACT We examine the spatial distribution and orbital pole correlations of satellites in a suite of zoom-in high-resolution dissipationless simulations of Milky Way (MW)-sized haloes. We use the measured distribution to estimate the incidence of satellite configurations as flattened and as correlated in their orbital pole distribution as the satellite system of the MW. We confirm that this incidence is sensitive to the radial distribution of subhaloes and thereby to the processes that affect it, such as artificial disruption due to numerical effects and disruption due to the central disc. Controlling for the resolution effects and bracketing the effects of the disc, we find that the MW satellite system is somewhat unusual (at the ≈2–3σ level) but is statistically consistent with the Lambda cold dark matter model, in general agreement with results and conclusions of other recent studies.

An ensemble modelling approach for spatiotemporally explicit estimation of fish distributions using data assimilation

This article presents a novel method for estimating large scale spatiotemporal distribution patterns of fish populations modelled at the individual level. A single realization of an individual-based model calibrated on historic data has weak predictive capacity, given the underlying uncertainties faced when modelling a relatively small cluster of individuals operating in a high dimensional spatial plane. By incorporating real-time data sources to update these models, we can improve their predictive capacity. When correcting estimates from a large population of individuals, we don’t have access to information about individual histories, such as information derived from tagging data. We propose mapping individuals to derived density matrices, which can be corrected using conventional data sources which describe a mass of individuals e.g. catch data. An ensemble of derived states are used as forecast inputs to an assimilation procedure, that calculates an analysis state matrix of the same form. An individuals’ position and biomass values are updated based on the analysis values. To assess the effect of corrections, we setup a simulation experiment to explore the impact the number of measurement points has on the updated spatiotemporal distribution. The measurement points were sampled from derived states of a twin model that resembles the original model. The output of the twin model serves as the true distribution. With an increasing number of measurement points the centre of mass of the modelled distribution converges on the true distribution and the two distributions increase in overlap. Additionally, the absolute error between model and true values decreases. This estimation method, applied to individual-based models and coupled with real-time fisheries data, can improve spatially explicit estimates of fish distributions.