Profile Contours Research Articles

Enhancing Path Planning Efficiency for Underwater Gravity Matching Navigation with a Novel Three-Dimensional Along-Path Obstacle Profiling Algorithm

This paper presents a study on enhancing the efficiency of underwater gravity matching navigation path planning in a three-dimensional environment. Firstly, to address the challenges of the computational complexity and prolonged calculation times associated with the existing three-dimensional path planning algorithms, a novel Three-Dimensional Along-Path Obstacle Profiling (TAOP) algorithm is introduced. The principles of the TAOP algorithm are as follows: (1) unfolding obstacles along the path using the path obtained from two-dimensional planning as an axis, interpolating water depth values based on downloaded terrain data, and subjecting obstacles to dilation treatment to construct a dilated obstacle profile for path segments; (2) conducting height direction course planning and a secondary optimization of the path based on the profile contours of the dilated obstacles; and (3) integrating height planning with the path points from two-dimensional planar planning to obtain a complete path containing all turning points in the three-dimensional space. Secondly, gravity anomaly data are utilized to delineate gravity suitability areas, and a three-dimensional planning environment that is suitable for underwater gravity matching navigation is established by integrating seafloor terrain data. Under identical planning environments and parameter conditions, the performance of the TAOP algorithm is compared to that of the RRT* algorithm, Q-RRT* algorithm, and Depth Sorting Fast Search (DSFS) algorithm. The results show that, compared to the RRT* algorithm, Q-RRT* algorithm, and DSFS algorithm, the TAOP algorithm achieves efficiency improvements of 15.6 times, 5.98 times, and 4.04 times, respectively.

Numerical and experimental investigation on the material removal profile during polishing of inner surfaces using an abrasive rotating jet

Inner surface components with a high level of precision are extensively utilized in contemporary industry. Polishing of inner surfaces and precise control of profile contours are extremely difficult due to space constraints and the surface shape. To realize ultraprecision polishing of inner surfaces, this paper proposes an abrasive rotating jet polishing (ARJP) method, in which a new type of polishing process with an infinitely adjustable incidence angle is adopted to realize ultraprecision polishing of the inner surfaces of workpiece made of aluminium alloy 6061. The precision of inner surface profiles strongly depends on the accuracy of the material removal profile prediction. A computational fluid dynamics approach is used to simulate and analyse the material removal profile of the workpiece inner surface during the ARJP process for a novel polishing process and tools. A series of inner surface polishing experiments demonstrate that the average error between the actual material removal depth and model simulation results is less than 5.9% and that the roughness of the inner surface is reduced from 0.200 µm to 0.046 µm, a 77% improvement in inner surface roughness.

Design and development of high precision four roll CNC roll bending machine and automatic control model

In recent years, advancements in industries such as aerospace, military weaponry, automobiles, locomotives, and shipbuilding have led to a surge in the demand for bent and rolled components, along with increasingly stringent requirements for rolling precision. However, the traditional hydraulic cylinder feeding solution has hindered further enhancements in the accuracy of rolled profile contours. Additionally, owing to variations in profile specifications, material properties, and an assortment of random factors during the forming process, the applicability of existing forming formulas remains limited, rendering them suitable only for profile processing under specific circumstances. To address these challenges, servo electric cylinders have been introduced as a replacement for traditional hydraulic cylinders, and the mechanical structure of a four-roll bending machine has been re-engineered. This innovation has demonstrated the feasibility of employing servo electric cylinders in four-roll CNC bending machines for profile bending, resulting in higher control precision and faster response times, ultimately providing a comprehensive design solution for four-roll CNC bending machines. In response to the limited universality of existing forming formulas, the actual R (profile forming curvature) and d (servo electric cylinder feed) values from the four-roll CNC bending machine have been utilized, and curve fitting methods have been implemented as the foundation for the automatic control model. This approach offers a high degree of universality, making it suitable for a wide range of applications. Moreover, as the number of trials increased, forming precision progressively improved.

Dental balance in the arcs for the implants: a concise systematic review

The teeth together perform the functions of mastication, protection, and support of related soft tissues, help in the articulation of words, and are an important factor in the aesthetics of the face. The macro geometry of the implant provides influences on osseointegration. In this sense, the various isolated characteristics (thread type, thread pitch, thread depth, face angle) must be studied so that the implant geometry can balance the compressive stress and tensile stress and produce a minimum shear force. The present study aimed to carry out a concise systematic review of the main considerations of dental balance in the arches in implant dentistry. Thus, knowledge of the direction of the teeth is of great importance in clinical implant dentistry for the correct installation of implants, which are very important for maintaining the balance of forces exerted by masticatory muscles (masseter muscle, temporal muscle, medial pterygoid muscle). In addition to this, the evaluation of the amount and density of bone available in the patient's edentulous site. It was concluded that the optimized aesthetic positioning of the implant presents numerous factors for the good aesthetic performance of an implant-supported prosthesis. The main conditions of the soft tissues, the amount of bone, and the location and inclination of the placed implant can be cited as the main ones. The correct positioning of the implant is linked to the location and axial inclination of the implant, aiming to favor the emergence profile and aesthetic contours of the prosthesis. The ideal location for the implant would be the one assumed by the lost tooth root. Also, the location of the height of the cervical portion of this implant concerning the adjacent teeth is important for determining the prosthetic space available for making the restoration, as well as its emergence profile and the biological space of the surrounding soft tissues.

Bending and Torsional Stress Factors in Hypotrochoidal H-Profiled Shafts Standardised According to DIN 3689-1

Hypotrochoidal profile contours have been produced in industrial applications in recent years using two-spindle processes, and they are considered effective high-quality solutions for form-fit shaft and hub connections. This study mainly concerns analytical approaches to determine the stresses and deformations in hypotrochoidal profile shafts due to pure bending loads. The formulation was developed according to bending principles using the mathematical theory of elasticity and conformal mappings. The loading was further used to investigate the rotating bending behaviour. The stress factors for the classical calculation of maximum bending stresses were also determined for all those profiles presented and compiled in the German standard DIN3689-1 for practical applications. The results were also compared with the corresponding numerical and experimental results, and very good agreement was observed. Additionally, based on previous work, the stress factor was determined for the case of torsional loading to calculate the maximum torsional stresses in the standardised profiles, and the results are listed in a table. This study contributes to the further refinement of the current DIN3689 standard.

Identifying key channel variability functions controlling ecohydraulic conditions using synthetic channel archetypes

AbstractGeometric modelling of river channel topography is a method of design synthesis wherein specific 2D geometric elements of river topography, such as the bed profile, cross‐sectional shape and channel planform contours, are expressed mathematically in isolation and then combined to produce a 3D heightmap. We utilized the geometric modelling framework to synthesize channel terrains that reveal flow–form–function linkages to investigate what roles variability in bed roughness, thalweg elevation and channel width play in defining hydraulic and ecohydraulic conditions of a channel reach from baseflow to bankfull discharge. To achieve a robust inquiry for a range of settings, this study developed four distinct synthetic channel terrain models for each of three stream reaches of different channel types in the South Fork Eel River in northern coastal California, USA. To test the process‐based effects of these diverse terrain synthesis options, we compared the resulting hydraulic patterns and preferred habitat availability for fry/juvenile steelhead trout and coho salmon over a range of discharges. Among thalweg bed undulation, width variation and bed roughness, we found thalweg bed undulation was the key factor affecting the channel ecohydraulic response at baseflow condition. At bankfull condition, thalweg bed elevation had the largest effect in high‐order mainstem streams identified by gravel‐cobble dominated high width‐to‐depth, riffle‐pool sequences, width variation had the largest effect in mid‐order confined channels with gravel‐cobble, high width‐to‐depth ratio with expansions/contractions and bed roughness in low‐order streams with low width‐to‐depth ratio, high‐gradient, cobble‐boulder and step‐pool/cascade channels.

NOISE PROTECTION USING “BROKEN” PROFILE SCREENS

Problem statement. In the cities of Ukraine there are entire systems of urban noise sources, namely: road transport, industrial and municipal enterprises, rail transport (trams, railways), air transport, water transport, playgrounds, stadiums and sports grounds, etc. Some of these noise sources operate in the residential area, and some − on its borders. In the residential area of the city, the most powerful source of noise, which is more common, are traffic flows through main streets. At the same time there is a whole system of sources of traffic noise. These are streets of various purposes, parking lots, garages, multi-level interchanges of highways, car service stations and a whole system of public buildings and structures served by various public and other modes of transport. The purpose of this article is ability to increase the effectiveness of noise protection in a particular situation, without increasing the geometric dimensions of the screen. Conclusions. The use of noise protection screens «broken» profile under certain urban conditions may be much more effective than the use of flat screens. Screens «broken» profile can be not only those that directly protect the noise source of the structure, but it can be different pavilions, canopies used for various purposes, away from the noise source and the upper surface of the profile contours of main buildings (shops, garages) etc. If, as a result of calculating the screen of the «broken» profile, the upper «broken» part of the screen will create a large tipping moment, it will be possible to keep the structure in balance not only by strengthening the foundation. In this case, you can use different stiffness diaphragms, special extension cables that support the sloping part, etc., depending on the specifics of specific urban conditions. The use of noise protection screens «broken» profile will reduce the height of the mark of the highest horizon of the structure and significantly reduce the cost of material for its manufacture.

Formation of Lateral Sliver Defects in the Platform Region of Single-Crystal Superalloy Turbine Blades

Sliver defects are known to extend along the casting axial direction. In this study, the lateral sliver defects on the platform base of single-crystal (SX) superalloy turbine blades were detected by macrocorrosion and electron backscattering diffraction. It was identified that misorientation between adjacent sliver textures was limited within medium-angle misorientation defects (10.5 deg). Moreover, the lateral sliver defects were more prone to occurring at a lower withdrawal rate. Based on the evolution of thermal profile and stress contours, the high stresses around the boundary between the blade body and the platform region were supposed to be the formation mechanism of lateral sliver defects.

Experimental investigations and numerical prediction on the effect of shielding area and post flow time in the GTAW of CP Ti sheets

In this study, bead on plate (BoP) trials are conducted on 2-mm thick commercially pure titanium (CP Ti) sheets by gas tungsten arc welding (GTAW) process. Welding current (75–105 A) and joining speed (250–300 mm/min) are taken as the variables. In the weld samples’ appearance of the surface, colorizations are noticed for understanding the role of shielding gas. BoP trials are subjected to metallographic examination to measure weld profiles. These measured values are fed as input for the Goldak double ellipsoidal model to performing the GTAW process. For BoP trials, temperature profile and Iso-surface contours along the moving heat source direction are taken at various time intervals. From the temperature history, shielding area and post flow time are identified. A shielding arrangement is fabricated and implemented based on these bead profile and temperature profile history. After the successful fabrication of shielding arrangement, experimental butt joints are made by GTAW process to verify the efficiency of shielding arrangement. Bead profile of experimentally fabricated 1.6-mm and 2-mm butt joints are compared and verified against the finite element model results. Moreover, cupping test is conducted to analyze the ductility of the joints. The maximum elongation of 96.10% is measured for 1.6-mm face out joints from cupping test.

Analisis Profil Iklim Mikro Pada Budidaya Cabai Rawit (Capsicum Frutescens L) Menggunakan Bahan Sungkup Plastik, Paranet, dan Kombinasi

The hood is an alternative to overcome the high intensity of sunlight. In this study the type of containment material treatment can be divided into 3 types of containment material, namely the type of plastic lid material, paranet and combination. For microclimate measurements, a temperature and humidity meter and a light meter are used. Microclimate measurements were carried out at 12.00 WITA, on cayenne pepper from 7 days to 35 HTS. Micro climate data analysis is done by interpolation to obtain the profile contour lines. The results of the study showed that there were different shapes and distribution of different micro-climate profile contours, especially in light intensity. At air temperature and air humidity can not obtain contour lines, because the results of the data from the research conducted are not much different. Plant growth rates in each treatment showed different productivity. In this type of paranet lid material shows better results compared to the type of plastic hood and combination material. In this type of paranet lid material produces an average dry weight of 247.9 grams.
 Keywords: hood type material, cayenne pepper plant, microclimate.

A Technique to Transfer the Emergence Profile Contours of a Provisional Implant Crown to the Definitive Impression.

This clinical report describes a method to create a proper emergence profile and accurately transfer it to the definitive impression, using an indirectly fabricated modified impression post. A provisional screwretained crown was indexed with a polyvinyl siloxane material. An autopolymerizing acrylic resin was used to modify an impression post on the polyvinyl siloxane index, which was then screwed onto the implant for the definitive impression after proper soft tissue healing. The indirectly fabricated modified impression post helped to transfer the contours to the definitive impression with minimal soft tissue irritation.

Piecewise-planar reconstruction using two views

The article describes a reconstruction pipeline that generates piecewise-planar models of man-made environments using two calibrated views. The 3D space is sampled by a set of virtual cut planes that intersect the baseline of the stereo rig and implicitly define possible pixel correspondences across views. The likelihood of these correspondences being true matches is measured using signal symmetry analysis [1], which enables to obtain profile contours of the 3D scene that become lines whenever the virtual cut planes intersect planar surfaces. The detection and estimation of these lines cuts is formulated as a global optimization problem over the symmetry matching cost, and pairs of reconstructed lines are used to generate plane hypotheses that serve as input to PEARL clustering [2]. The PEARL algorithm alternates between a discrete optimization step, which merges planar surface hypotheses and discards detections with poor support, and a continuous optimization step, which refines the plane poses taking into account surface slant. The pipeline outputs an accurate semi-dense Piecewise-Planar Reconstruction of the 3D scene. In addition, the input images can be segmented into piecewise-planar regions using a standard labeling formulation for assigning pixels to plane detections. Extensive experiments with both indoor and outdoor stereo pairs show significant improvements over state-of-the-art methods with respect to accuracy and robustness.

Numerical Investigation of a Mixed Convection Flow in a Lid-Driven Cavity

This study is devoted to the computational fluid dynamics (CFD) modeling of steady laminar mixed convection flow and heat transfer in lid driven cavity (10 ≤ Re ≤ 1000). The ratio of the height to the width of the cavity is ranged over H/L = 0.5 to 1.5. The governing equations are solved using commercial finite volume package FLUENT to visualize the nature of the flow and estimate the heat transfer inside the cavity for different aspect ratio. The simulation results are presented in terms of average Nusselt number of the hot wall, velocity profile, and temperature contours. It was found that the average Nusselt number inside the cavity is strongly governed by the aspect ratio as well as the Reynolds number. A parametric study is conducted to demonstrate the effect of aspect ratio on the flow and heat transfer characteristics. It is found that heat transfer enhancement was obtained by decreasing the aspect ratio and/or increasing the Reynolds number.

A novel method for estimating the complete 3D shape of pottery with axial symmetry from single potsherds based on principal component analysis

Recording ceramic potsherds recovered during archeological excavation is an essential task for both the archeological interpretation and conservation because of the evidence they represent. However, complete vessels provide additional data such as food storage capacity, and physical dimensions that surpasses the information that can be extracted from a single potsherd. This paper proposes a novel digital approach intended to improve the archeological registration and interpretation by the complete 3D shape reconstruction of pottery with axial symmetry based on the 2D recordings of single potsherds. A 3D laser scanner and photogrammetry are used to acquire the mesh models of potsherds and complete vessels, respectively. Subsequently, 2D generator profiles are extracted from the models by calculating the contour, axis of symmetry, and diameter of the rim’s potsherd. Then, a database of profile contours of complete vessels was established, classified and utilized in the reconstruction algorithm using Principal Component Analysis (PCA) in order to obtain a 3D complete representation of pottery estimated from a single potsherd. The proposed method was applied in the study of pottery developed by Pre-Hispanic civilizations on the north coast of Peru for the preparation and consumption of a maize-based alcoholic beverage. Accuracy experiments report errors of less than 6.25% for the 3D reconstruction of complete vessels from single potsherds. Nevertheless, experiments demonstrate that the use of a large enough database in the reconstruction algorithm leads to accuracy errors less than 0.66%.

Changes in soft tissue profile following the treatment using a Herbst appliance: A photographic analysis

Aesthetics is the reason for most of the class II malocclusion patients to opt for orthodontic treatment. In order to regulate retrognathic profile Herbst appliance for anterior movement of the mandible can be a treatment of choice. The aim of this study was to determine the soft tissue profile changes following Herbst appliance therapy on before and after treatment photos, using the computer program. This investigation was performed on profile photographs of 20 class II patients (12 females and 8 males) aged 18-23 years. Analysis of the changes in soft tissue facial structure relationships evident on the photographs before and after the Herbst appliance therapy was performed using Bentley Micro Station program. The first contour of the soft tissue profile was marked. The following reference lines were subsequently traced: Ricketts aesthetic E line and Juanita line. The area enclosed by these two lines included the nose, upper and lower lip, chin and free space in front of the lips. Using the computer program, the surfaces of the soft tissue structures and free space defined by the reference lines and profile contours were measured. Calculation of the relative proportion of surfaces was done for each photograph. The data obtained were then compared for each patient before and after the treatment. Skeletal and dentoalveolar treatment effects that support soft tissue changes were presented by the profile cephalometric parameters of sagital occlusion (SO) analysis. A reduction in the relative surface of the upper lip in males (p < 0.01) and females (p < 0.05) was shown by the pictures. The space occupied by the chin was reduced after the treatment for females only (p < 0.05). The relative surface of the nasal soft tissues, that was included in the reference space was increased (p < 0.01) in both genders. The relationship between the soft tissue and empty surface was changed in favor of the empty surface (p < 0.05) in females. No statistically significant differences were found between the males and the females, before or after the Herbst appliance therapy. The soft tissue changes were the consequence of skeletal and dentoalveolar treatment effects: upper incisors retrusion, lower incisor protrusion and forward movement of the lower jaw. The Herbst appliance therapy caused a significant improvement of the profile appearance. The extent of soft tissue changes that occur on its dentoalveolar and skeletal support is a complex issue.

Class II Composite Restorations and Proximal Concavities: Clinical Implications and Management

Clinical experience supports the notion that the restoration of MOD cavities may pose a challenge to the practitioner. Proper placement of precontoured matrices and commercial wedges help the clinician to establish an optimal emergence profile and sufficient contours. However, the presence of proximal concavities in premolars or molars can turn the reproduction of previous cervical architecture into an even more demanding task. Wedges with customized form or adequate design can precisely conform the matrix to the cavosurface area and prevent any gap formation. This article presents two different options that allow for successful and predictable reestablishing of anatomically correct contours and optimal proximal contacts in posterior teeth with proximal concavities.

Achieving a Desired Esthetic Outcome for a Single-Tooth Implant Restoration with Tissue Excess Using a Multidisciplinary Treatment Approach: A Clinical Report

Achieving ideal emergence profile and restoration contours for implant-supported prostheses in the anterior esthetic zone is a prime requisite. In this report, the patient presented with decreased restoration space and unfavorable tissue contours for an implant restoration. Correction of space deficiency and reshaping of excess bone height and soft tissue were planned and executed carefully prior to definitive restoration of a maxillary anterior missing tooth with an implant-retained prosthesis. Post-treatment evaluation of the papillary levels and soft tissue profile helped in assessing maintenance of the restored emergence profile.

Deriving statistical fit contours and shape of an aerosol mask from 3D head scans

This paper deals with mask shape design to ensure a statistical fit for a given population represented by tessellated 3D head scans. The mask rim curve should contact the face without gaps. This work identifies corresponding points on the mask and facial landmarks. The landmarks define a coordinate frame which helps extract rim contours (mask contours) and facial midline contours (profile contours) from the 3D model. Bilateral symmetrisation procedures are used to correct mild asymmetry in the mask contours. The statistical distribution induced by the contours on a grid is used to derive percentile contour geometries. Mask shapes generated by stacking elliptic cross sections, scaling and convex hull have been explored. 5th, 50th and 85th percentile masks are used for visual fit evaluation on a set of representative faces. The procedure establishes that the landmark-based approach provides a systematic method not only for design but also for fit evaluation.

Fourier Descriptor Analysis and Unification of Voice Range Profile Contours: Method and Applications

To describe a method for unified description, statistical modeling, and comparison of voice range profile (VRP) contours, even from diverse sources. A morphologic modeling technique, which is based on Fourier descriptors (FDs), is applied to the VRP contour. The technique, which essentially involves resampling of the curve of the contour, is assessed and also is compared to density-based VRP averaging methods that use the overlap count. VRP contours can be usefully described and compared using FDs. The method also permits the visualization of the local covariation along the contour average. For example, the FD-based analysis shows that the population variance for ensembles of VRP contours is usually smallest at the upper left part of the VRP. To illustrate the method's advantages and possible further application, graphs are given that compare the averaged contours from different authors and recording devices--for normal, trained, and untrained male and female voices as well as for child voices. The proposed technique allows any VRP shape to be brought to the same uniform base. On this uniform base, VRP contours or contour elements coming from a variety of sources may be placed within the same graph for comparison and for statistical analysis.

Component-specific scale for inline quality assurance of spatially curved extrusion profiles

Spatially curved Al-extrusion profiles are often used for lightweight frame structures in vehicle manufacturing. Within the Collaborative Research Centre SFB/Transregio 10, an automated product-flexible process chain is established in order to produce and machine such profiles and to join them into frame structures. One of the biggest challenges of this process chain consists in handling, clamping and machining variably formed profiles with precision and without having to change the mechanical system. For this, both the contour of the profile and the position and orientation of the profile during the process have to be determined. In order to have this information provided from inside the process chain, a component-specific scale was developed and realised for the contour detection and precision positioning of multi-dimensionally curved extrusion profiles. The scale is applied onto the surface of the profile by a laser. To determine the contour, the scale is scanned using digital image processing and the profile is measured by a laser triangulation sensor. This establishes the relation between component scale and profile contour. If required, the position of the profile can be readjusted by scanning individual markings again during machining. It is not necessary to re-measure the entire profile contour. The process can be used for different profile contours and profile lengths without having to change the mechanical system. The first section of this article describes the approach for contour detection and precision positioning and its validation for straight profiles, 2D curved profiles and 3D curved profiles with a test rig. Then, the implementation of the validated process into a process chain is described, including the inline application of the scale, the inline profile measuring and the precision positioning of spatially curved profiles during machining.