Geometric Elements Research Articles

SEGMENTAL LASER STRIPPING OF THIN COATINGS ON MONOLITHIC CUTTING TOOLS

This study outlines the methodology of the new approach of laser stripping technique in functional surfaces of monolithic cutting tools. Starting from the initialization test of the coating thickness using a laser calotest including beam-material interaction test, through the introduction of the main geometrical elements necessary for the analysis of the tool, the study discusses segmental laser stripping including its evaluation, where the effects of different segment modifications (overlapping, resizing, rotation or reordering) were investigated. The influence of the presented technology on the microgeometry of the tool was beneficial from several points of view: the area around the cutting edge can be influenced by the polarization of the laser beam and the resulting radius values show no negative influence of the substrate by the laser.

The ethmoid bone is the ideal graft to strengthen nasal septum L-strut among different grafts: An evaluation based on finite element analysis.

In the rhinoplasty of Asian short nose deformity, the surgeon cuts a portion of septal cartilage and retains the nasal septum L-strut, but a deviated nasal septum is formed after the surgery under forces of soft tissue contracture. Although various autologous grafts are used to reinforce the L-strut, there is a lack of objective "mechanical theory" to support the clinical findings in other studies at the present time. A simplified and geometrical finite element model of L-strut reinforced with clinically common materials, including auricular cartilage, nasal septal cartilage, and perpendicular plate of ethmoid, was established. Simulating the mechanical environment of nasal tip in reality, when the force was loaded, the von Mises stress and directional deformation of the L-strut were observed under different widths. Kruskal-Wallis test was used to examine the significance of intergroup differences of L-strut, and P<0.05 indicated statistical significance. All autologous grafts decreased the maximum directional deformation of L-strut, and the variance of nasal tip displacement was reduced; the perpendicular plate of ethmoid showed a distinct effect. The increasing width of the L-strut reduced the maximum displacement of the nasal tip, but the influence of using grafts as a reinforcement to the L-strut was much greater than the residual width (p=0.003). The graft reinforcement significantly increased the stability of the L-strut, which enhanced the resistance to deformation in the long-term action of tension, and the effect of the perpendicular plate of ethmoid to reinforce was significantly better than that of auricular and nasal septal cartilage.

Influence of geometric elements of roundabouts on circulating lane speed (roundabout)

Research conducted in recent decades has shown that there are significant variations in speed at roundabouts depending on the geometric elements. Due to the characteristics of roundabouts and the way vehicles move, there is a reduction in speed, not only in the roundabout zone, but also in circulation (roundabout). This paper analyzes the influence of different types of roundabouts as one of the elements of the street system, on speed as one of the basic parameters of traffic flow that defines the functionality and quality of traffic conditions.

Interior Soft Decoration Product Design Based on 3D Modeling and Image Processing Technology

In order to solve the problems of the traditional 3D simulation system of indoor soft decoration, such as the lack of effective enrichment, rendering means, and poor authenticity when selecting the geometric modeling method to simulate the effect of indoor soft decoration, this paper proposes a 3D simulation system of indoor soft decoration based on OpenGL and Direct3D. The system uses 3DMAX software to establish the indoor model, imports the model into the OpenGL 3D graphics standard library module, draws the indoor soft decoration scene elements using the basic geometric elements, and constrains the scene elements through the wall, overlap, and size constraint functions, so as to ensure the reasonable layout of the indoor soft decoration agent area and enrich the indoor model. After enrichment, the indoor model is transmitted to the Direct3D rendering engine module transformation unit to implement the soft decoration layout, and the lighting unit and rasterization unit are used to render the indoor after layout so as to obtain the optimal indoor soft decoration effect and output the 3D simulation image of indoor soft decoration. The experimental results show that the favorability, operation sensitivity, design portability, design satisfaction, and soft fitting effect score of the system are higher than those of the Untiy3D system and Smart3D system. The average score of this system is about 95, while the average score of the Untiy3D system is lower than 89, and the average score of the Smart3D system is lower than 85. Conclusion. The three-dimensional simulation effect of indoor soft decoration of this system is good, the design is convenient, the operation is sensitive, and the user satisfaction is high, which provides a reliable analysis basis for indoor design.

Asymptotical outer synchronization control of the complex dynamical networks via unknown interaction and links dynamics

The nodes and links connecting them are the two main geometric elements of a complex network. If the nodes and links change over time, all the nodes and all the links are regarded the dynamic systems, respectively, and thus, a complex dynamical network (CDN) can be regarded to be composed of the two interconnected subsystems: the nodes subsystem (NS) and the links subsystem (LS). The outer synchronization happens in two CDNs, which means that the state error between the two NSs converges to zero. However, the dynamics of LS is ignored in the existing literature about the outer synchronization. In addition, the existing literature rarely consider the unknown interaction between two CDNs into the outer synchronization. In view of this, this paper investigates the outer synchronization of two CDNs with the unknown interaction. By using the dynamics of LSs and synthesizing the adaptive control scheme, the outer synchronization is asymptotically achieved. The results in this paper show that the outer synchronization happens when the two LSs can track, respectively, the synthesized auxiliary dynamic tracking targets. Finally, the numerical simulation is given to show the effectiveness of the theoretical results in this paper.

ПРОБЛЕМАТИКА ЕКСПЛУАТАЦІЙНОЇ ДОВГОВІЧНОСТІ ТЕХНІЧНИХ ЗАСОБІВ ОРГАНІЗАЦІЇ ДОРОЖНЬОГО РУХУ

Introduction. The efficiency of road transport functioning greatly depends on the technical level and condition of roads. Modern roads must ensure traffic safety. Also, it has to be considered that the transport and operational level of a modern road is determined not only by the combination of geometric elements of the route, the number of traffic lanes, the condition of the roadway and roadsides, but also the engineering equipment of the road. Mostly, traffic safety requirements are met dut to a wide and skillful use of engineering equipment. Modern standards include, among other things, technical means of traffic control of the roads. Problem statement. The impact of various factors on the durability of polymeric materials Purpose. Solving the issues of operational durability of technical means of traffic control. Materials and methods. Theoretical and empirical methods of scientific researches are used to analyze the impact of various factors on the durability of polymeric materials. Results. The analysis of foreign researches concerning the impact of various factors, and especially ultraviolet radiation on durability of polymeric materials is performed. Conclusions. When conducting tests on artificial aging in order to predict changes in the properties of polymeric materials, it is necessary first of all to select and justify the simulated external factors and their maximum values. When determining the allowable amplification of the selected external factor as compared to its influence under operating conditions, it is necessary to be guided by the following: at the maximum value of the external aging factor in artificial conditions, the physical and chemical aging processes must be identical to those occurring in real operating conditions. Since, taking into account this condition, we will be able to obtain the most qualitative and accurate indicators.

The impact of geometric and land use elements on the perceived pleasantness of urban layouts

This article presents a model to estimate the impact of geometric and land use elements on citizens’ perception of urban layout pleasantness. An ordinal regression cumulative link mixed model with those elements as regressors is proposed and calibrated using data from an online survey. Results show that landscape building height and density of green areas are the factors that most impact the perception of pleasantness. Based on the model, a methodology to derive pleasantness mean scores for a city is also proposed and applied to a case study. The methodology allows for benchmarking the pleasantness of different cities or comparing neighborhoods within a city. It can be used both as an urban evaluation tool and a decision-aid for city expansion programs.

Methodologies to Determine Geometrical Similarity Patterns as Experimental Models for Shapes in Architectural Heritage

Today, plans to protect historic buildings focus on managing architectural heritage sustainably. Technical teams, such as architects and restorers, use massive data acquisition techniques, so an identification mechanism is required to select geometrical similarity patters to support hypothesis that guarantee historical data. Moreover, computational methods are required to understand the role of organic shapes in historic buildings. This paper first describes an extensive review of the literature and then the algorithms and methods to compare and to detect similar geometrical elements and complex patterns in architecture and archaeology. For this purpose, two key aspects are considered: the metric standpoint and historical-graphical features of the 3D models, i.e., composition, techniques, styles, and historical-graphical documentary sources. Research implies testing several methodological lines to know the similarity degree of complex organic shapes in architectural details through statistical analysis, software to assess point clouds, and complex curve analysis. The results have shown that the three procedures can be compared and that the bases of the pillars of both the Cathedral of Seville and the churches in Carmona, Jerez, and Morón are very similar; however, the base of the pillar of the church in Carmona presents scalability variations.

건축 디자인의 생명체적 형태와 변형의 표현에 관한 연구

This study aims to understand the shapes of living things from classical architecture to modern architecture and understand the change of form in architectural design chronologically and expressing the form and sense of living Organism. The Form and Developments were expressed directly, and the relationship between shapes and aspects of genesis, development, and structurization were considered. These aspects were systematized in detail through specific examples. This study focused on the expression of living organism and transformations among the expression systems of various senses. In Chapter 4, the aspects and systems of such expressions were synthesized, and the relation of a lot of keywords was structured and presented in tables and diagrams. It can be seen that the detailed system of expression of senses of living organism works extensively in the architectural realm. It provides an important driving force for the development of modern architecture into a dynamic and organic form. In this study, in the development of modern architectural design spanning form, space, sense, and experience, the expression of the sense of living organisms was developed in detail through the relationship between various geometrical expressions and elements historically. Elements that sense and express living energy, development, and change are systematized in detail. Through this study, it is possible to schematically understand the flow of geometrical development of the dynamic, living and non-formal architecture of modern architecture.

EVALUATION OF DEFORMABILITY OF MATERIAL DURING PLANTING OF ELEMENTS OF PREPARATIONS BY ROLLING STAMPING METHOD

The article presents the results of development and research of technological schemes of planting flanges on tubular (ring) workpieces by stamping by rolling cylindrical and conical rolls. It is shown that the achievement of significant dimensions of the various elements of the workpiece is possible by providing a directed flow of metal by changing the relative position of the roll and the workpiece. Planting of external flanges is one of the most effective operations of stamping by rolling, as it allows you to form a wide range of products with advanced geometric elements. To assess the technological capabilities of the flange landing operation, the most dangerous from the destruction positions of the workpiece zone was identified and the analysis of the stress-strain state of the material using the method of grids, hardness measurement and microstructural analysis. According to the results of the research, the ways of deformation of the particles of the material of the peripheral surface of the flange in the coordinates "intensity of deformations - an indicator of the stress state" are schematically constructed. These deformation paths are given against the background of curves of ultimate deformations of steels, which are built on the results of uniaxial compression and torsion of cylindrical specimens and using tested approximations. A mathematical model of deformation trajectories is constructed, for which a one-parameter function is taken as a basis, which is "glued" from the elementary function of the sine and tangent to it at some point in the line. To determine the used plasticity resource, a damage summation model with a power approximation of the damage function was adopted. As a result, we have for the first time described the general expression of the linear damage summation model for the case of the parametric deformation path problem. The graphical representation on the constructed model of accumulation of damages in material of a dangerous zone of a flange at landing by a method of SHO is resulted. Based on the constructed model, it is possible to model the accumulation of damage by changing the values of the model parameters for different materials and deformation paths, which, in turn, depend on the relative geometric parameters of the workpiece and its location relative to the rolling roll.

Sound Scattering by Gothic Piers and Columns of the Cathédrale Notre-Dame de Paris

Although the acoustics of Gothic cathedrals are of interest to researchers, the acoustic impact of their many columns is often neglected. The construction of the Cathédrale Notre-Dame de Paris spanned several centuries, including a wide variety of architectonic elements. This study investigates the sound scattering of a selection of seven designs that are relevant to this building as well as to the architectural style itself. These were measured on scale models (1:8.5 to 1:12), using a subtraction method, for receivers at about 3 m at full scale and a far-field source. They were also numerically simulated using a finite-difference time-domain method in two-dimensional space with an incident plane wave. The method integrates a finite volume framework to employ an unstructured mesh conforming to the complex geometries of interest. The two methods are in strong agreement for the considered configurations. Relative levels to the direct sound of backscattered reflections between −10 dB and 2 dB and between −15 dB and −6 dB in the transverse directions were estimated for the dimensions considered, relative to reported reflection audibility thresholds. Cross-sections with smaller scale geometrical elements on their perimeter can produce diffuse reflections similar to those of surface diffusers.

The cellular basis for synergy between RCO and KNOX1 homeobox genes in leaf shape diversity

Leaves of seed plants provide an attractive system to study the development and evolution of form. Leaves show varying degrees of margin complexity ranging from simple, as in Arabidopsis thaliana, to fully dissected into leaflets in the closely related species Cardamine hirsuta. Leaflet formation requires actions of Class I KNOTTED1-LIKE HOMEOBOX (KNOX1) and REDUCED COMPLEXITY (RCO) homeobox genes, which are expressed in the leaves of C.hirsuta but not A.thaliana. Evolutionary studies indicate that diversification of KNOX1 and RCO genes was repeatedly associated with increased leaf complexity. However, whether this gene combination represents a developmentally favored avenue for leaflet formation remains unknown, and the cell-level events through which the combined action of these genes drives leaflet formation are also poorly understood. Here we show, through a genetic screen, that when a C.hirsuta RCO transgene is expressed in A.thaliana, then ectopic KNOX1 expression in leaves represents a preferred developmental path for leaflet formation. Using time-lapse growth analysis, we demonstrate that KNOX1 expression in the basal domain of leaves leads to prolonged and anisotropic cell growth. This KNOX1 action, in synergy with local growth repression by RCO, is instrumental in generating rachises and petiolules, the linear geometrical elements, that bear leaflets in complex leaves. Our results show how the combination of cell-level growth analyses and genetics can help us understand how evolutionary modifications in expression of developmentally important genes are translated into diverse leaf shapes.

A Local Enhancement Method for Large-Scale Building Facade Depth Images using Densely Matched Point Clouds

In recent years, laser scanning systems have been widely used to acquire multi-level three-dimensional spatial objects in real time. The laser scanning system is used to acquire the three-dimensional point cloud data of urban scenes. Due to the large-scale characteristics of urban scenes, and the problems of scanning occlusion, scanning path, and limited scanning laser range, the laser scanning system cannot scan every object in the scene comprehensively, multidirectionally and finely, so the corresponding three-dimensional point cloud data collected by many objects are incomplete, and the data images are relatively sparse and unevenly distributed. The existing point cloud denoising and enhancement algorithms, such as AMLS, RMLS, LOP, and WLOP, all use local information to enhance the missing or sparse parts of the point cloud. This point cloud enhancement method is only limited to a small range and cannot do anything for the larger missing area of the point cloud. Even if it is done reluctantly, the effect is not satisfactory. There are a lot of repetitive and similar features in urban buildings, such as the repetitive areas of floors and balconies in buildings. These repetitive areas are distributed in different positions of point clouds, so the repetitive information has non local characteristics. Based on the nonlocal characteristics of building point cloud data and the repetitive structure of buildings, this article proposes a nonlocal point cloud data enhancement algorithm, which organizes the point cloud data in the repeated area into a set of basic geometric elements (planes). The structures are registered in a unified coordinate system, and the point cloud is enhanced and denoised through two denoising processes, “out-of-plane” and “in-plane.”

Ultrafast laser nanostructuring in transparent materials for beam shaping and data storage [Invited

We review recent progress in femtosecond laser anisotropic nanostructuring of transparent materials, including silica glass and thin films. With different writing parameters, oblate nanopores, single lamella-like structures and nanoripples are demonstrated, which can be used in geometric phase optical elements, space variant polarization converters and multiplexed optical data storage.

Extraction of Step-Feature Lines in Open-Pit Mines Based on UAV Point-Cloud Data

Step-feature lines are one of the important geometrical elements for drawing the status quo maps of open-pit mines, and the efficient and accurate automatic extraction and updating of step-feature lines is of great significance for open-pit-mine stripping planning and analysis. In this study, an automatic extraction method of step-feature lines in an open-pit mine based on unmanned-aerial-vehicle (UAV) point-cloud data is proposed. The method is mainly used to solve the key problems, such as low accuracy, local-feature-line loss, and the discontinuity of the step-feature-line extraction method. The method first performs the regular raster resampling of the open-pit-mine cloud based on the MLS algorithm, then extracts the step-feature point set by detecting the elevation-gradient change in the resampled point cloud, further traces the step-feature control nodes by the seed-growth tracking algorithm, and finally generates smooth step-feature lines by fitting the space curve to the step-feature control nodes. The results show that the method effectively improves the accuracy of step-feature-line extraction and solves the problems of local-feature-line loss and discontinuity.

Degenerations of Pascal lines

Let $\mathcal{K}$ denote a nonsingular conic in the complex projective plane. Pascal's theorem says that, given six distinct points $A,B,C,D,E,F$ on $\mathcal{K}$, the three intersection points $AE \cap BF, AD \cap CF, BD \cap CE$ are collinear. The line containing them is called the Pascal line of the sextuple. However, this construction may fail when some of the six points come together. In this paper, we find the indeterminacy locus where the Pascal line is not well-defined and then use blow-ups along polydiagonals to define it. We analyse the geometry of Pascals in these degenerate cases. Finally we offer some remarks about the indeterminacy of other geometric elements in Pascal's hexagrammum mysticum.

Geometric Tolerance Control Method for Precision Machinery Based on Image Modeling and Novel Saturation Function

Abstract Research on the geometric tolerance control method of precision machinery based on image modeling and new saturation function. First, image-based modeling techniques provide a new way to control the saturation function with a dynamic boundary layer from a computer graphics perspective. Then, it proposes a method to represent the dimensional and geometric tolerances of precision machines using changes in the position of control points of geometric elements. Finally, the main content of the tolerance analysis method based on Monte Carlo simulation is proposed, that is, the position of the azimuth control point of all geometric elements on the measurement chain is determined experimentally by using a random number generator. Experiments have shown that the nominal distance between the control points is the nominal size of the geometric elements, and by comparing the variation of the control points with the nominal distance of the control points, it is easy to determine the relationship between tolerance and tolerance. accuracy.

Research on Geometric Design Standards for Freeways under a Fully Autonomous Driving Environment

The formulation of the current geometric design standard for freeways considers the influence of the “human-vehicles-road-environment” system. In the fully autonomous environment, the driver has been liberated from the system, which means that the influence of “human” will be reduced. The requirements or limitations of the freeway geometric design standard, which consider the driver’s psychological and physical factors in the traditional driving environment, can be more flexible in the fully automatic driving environment. By using the methods of comparative analysis, theoretical analysis, and theoretical calculation, this article researches the geometric design standard for freeways in an autonomous driving environment from four aspects: control elements of geometric design, horizontal alignment, vertical alignment, and cross-section elements. The main contribution of this article is to propose the recommended values of the geometric design standard for freeways in a fully autonomous driving environment, which can provide reference for the formulation of relevant standards or specifications for autonomous driving roads in the future.

Sivas Hoca İmam Mosque

Bu çalışmada Sivas şehir merkezinde yer alan Hoca İmam Camisi tanıtılacak ve değerlendirilecektir. Hoca İmam Camisi 14. yüzyılın ikinci çeyreğinde, Eretna Beyliği Dönemi’nde inşa edilmiştir. Sivas’ta inşa edilen erken tarihli mescitlerden biri olan yapı adını kurucusundan almış ve zamanla yapının bulunduğu mahalle de aynı isimle anılmıştır. Caminin kurucusu olan Hoca İmam tanınmış bir sûfîdir. 1373 yılında vefat edince adını verdiği mescidinin önüne defnedilmiş ve türbesi yapılmıştır. Mahalle mescidi olarak inşa edilen yapı, 1817 yılında Dergâh-ı Ali gediklilerinden Mehmet Emin Ağa tarafından onartılmış ve minber eklenerek camiye dönüştürülmüştür. Yapı sonraki yıllarda da bazı onarımlar geçirmiş, 1953 yılında harimi batıya doğru genişletilerek kuzeyine bir son cemaat yeri ile bir de minare eklenmiştir. Camide bitkisel, geometrik, nesneli ve mimari öğelerden oluşan alçı ve ahşap bezeme tespit edilmiştir. Caminin mihrabında alçı, minber, vaaz kürsüsü, tavan ve harim kapısında ise ahşap bezeme yer almaktadır. Alçı bezemeler baskı tekniğinde, ahşap bezemeler ise çakma tekniğinde yapılmıştır. Yapının mihrabındaki alçı süslemelerde, kenger yaprakları, vazodan çıkan çiçekler, kıvrım dallar gibi bitkisel motiflerin yanı sıra kandil motifleri ve mimari formlar kullanılmıştır. Bezeme üslubu Batılılaşma Dönemi özellikleri göstermektedir. Sivas’ta bu dönemlerde inşa edilen diğer yapılarda da karşılaşılan bu üslup dönemin beğenisini ve sanat anlayışını yansıtması bakımından önemlidir. Hoca İmam Camisi bu üslubun Sivas’taki önemli örneklerinden birini oluşturmaktadır.

Point and Line to Surface: The Geometric Elements of Display Color Modeling

Color appearance is multidimensional, and color space has been a useful geometric representation for display modeling and optimization. However, the three fundamental attributes of color, i.e., brightness, saturation, and hue, have not found their singly corresponding physical correlates. Changes along one physical dimension interfere with other color attributes, which has been a deficiency of the existing color spaces, particularly prevalent for high-dynamic-range and wide-color-gamut displays. This paper describes how we set out to develop independent color scales for each attribute. Based on both psychophysical experiments and computational modeling, the surfaces/lines of equal brightness/saturation, as well as the boundaries between surface versus illumination color modes, have been characterized. Furthermore, the independent relations between those new scales have been quantitatively evaluated. Those results promise a new color representation that is more intuitive and efficient for color controls in displays.