The Role of Contour Line in Painting — an Analysis of Morandi's Still Life Painting

In painting, line is one of the basic compositional elements and an important "tool" for artists to express their ideas. The combination of line and color, composition, and shape allows the viewer to feel the author's thoughts, emotions, or distinctive thinking through the picture. Foreign cave paintings, European pre-Renaissance oil paintings and modern paintings, and domestic Dunhuang murals, silk paintings of the Warring States period and cave paintings all show that the contour line has never disappeared despite its different roles in the changing times. Therefore, the artist's generalized expression of contour lines can become a characteristic of the picture that makes the artist stand out.

Frequency Contour-Strip Method for Characterization of Damage in Structures under Noisy Conditions

Eigen-frequency, compared with mode shape and damping, is a more practical and reliable dynamic feature to portray structural damage. The frequency contour-line method relying on this feature is a representative method to identify damage in beam-type structures. Although this method has been increasingly applied in the area of damage identification, it has two significant deficiencies: inefficiency in establishing the eigen-frequency panorama; and incompetence to identify cracks in noisy conditions, considerably impairing the effectiveness in identifying structural damage. To overcome these deficiencies, a novel method, termed the frequency contour-strip method, is developed for the first time. This method is derived by extending the frequency contour line of 1D to frequency contour strip of 2D. The advantages of the frequency contour-strip method are twofold: (i) it uses the isosurface function to instantly produce the eigen-frequency panorama with a computational efficiency several orders of magnitude higher than that of the frequency contour-line method; and (ii) it can accommodate the effect of random noise on damage identification, thereby thoroughly overcoming the deficiencies of the frequency contour-line method. With these merits, the frequency contour-strip method can characterize damage in beam-type structures with more efficiency, greater accuracy, and stronger robustness against noise. The proof of concept of the proposed method is performed on an analytical model of a Timoshenko beam bearing a crack and the effectiveness of the method is experimentally validated via crack identification in a steel beam.

TEMPLE SCULPTURES OF MANNA MAGUS AND THEIR PICTURING IN TABRIZ CARPETS OF XIX CENTURY

одной из личных коллекций в Горисе (Южный Азербайджан) хранится уникальный ковер. Этот ковер известен под названием «Семь планет». (Этот факт опубликован в книге Р.Тагиевой «Ковровые персонажи Низами», рисунок 40). Ковер был соткан в 1880 г. и по характеру изображенных на нем фигур автором был ковровщик-любитель. Уникальность этого ковра объясняется его содержательной составляющей. Следует также отметить, что в специальной литературе такие образцы не упоминаются. В центре ковра расположен прямоугольный медальон, а его кайма не очень широкая, состоит из трех полос. В этом медальоне теплый светло-коричневый цвет переходит в темно-коричневый. В медальоне размещены изображения семи планет. Эти планеты являются символами небесных звезд. В центре медальона изображено Солнце. Арабские надписи с названиями планет связаны с разными антропоморфными фигурами. Эти надписи расположены рядом на фоне четырех лопастных медальонов желтого цвета, обведенных желтой контурной линией. Все остальные фигуры расположены вокруг Солнца. Две из них расположены в верхней части, две – в нижней части медальона, а остальные четыре звезды находятся справа и слева от Солнца. Итак, размещение фигур – символов планет – повторяет схему размещения планет на небе. Исходя из этого, можно с уверенностью сказать, что древний обитатель Азербайджана изучал небо и имел собственные, возможно, примитивные представления о планетах. Сам Зороастр считался зороастрийским пророком и был ученым-астрологом, знал звезды и небо. По этой причине у древних греков имя Зороастр ассоциировалось с понятием «астрон» – звезда. Так, в древних источниках Зороастр описывается как мудрый астролог, основанное им учение называется зороастризмом. In one of personal collections in Goris (Southern Azerbaijan) a unique carpet is kept. That carpet is known by the name «Seven planets». (The fact is recorded by R.Tagiyeva in her book «Carpet characters of Nizami», picture 40). The carpet was woven in 1880 and judging by the character of figures, pictured on it, its author was amateur carpet-maker. Uniqueness of that carpet is explained by its content aspect. It should be also pointed, that in special literature such samples arenot mentioned. In the centre of carpet a rectangular medallion is placed, and its border isnot very wide, it consists of three stripes. In that medallion a warm, light-brown color transforms into dark-brown one (here ABRASH is seen). In the medallion pictures of seven planets are placed. These planets are symbols of heavenly stars. In the centre of medallion the Sun is pictured. (Arabian inscriptions with names of planets are connected with different anthropomorphous figures. These inscriptions are placed side by side, on the background of four paddle medallions of yellow color. These medallions are outlined by yellow contour line). All other figures are placed around the Sun. Two of them are placed in upper part, two of them are placed in bottom of medallion, and the rest four stars are on the right and on the left side of Sun. So, the placing of figures – symbols of planets – reproduces the scheme of planets placing in the sky. This facenables to presume, that ancient inhabitants of Azerbaijanstudied the sky and had their own,spmewhat primitive ideas about the planets. Zoroaster himself was considered a Zoroastrian prophet and anastrologer, he knew the stars and the sky. That was the reason, that the name Zoroaster for ancient Greeks was associated with notion «astron» – star. So, in ancient sources Zoroaster is described as wise astrologer, the doctrine, founded by him, is named Zoroastrism.

A New Method of Achieving Single Three-Dimensional Building Model Automatically Based on Oblique Photography Data

Operating and managing single three-dimensional building model individually are critical in the application of oblique photography models. However, these models are usually complete and continuous, and the single three-dimensional building model in these models cannot be managed individually. Generally, achieving a single three-dimensional building model requires a human-computer interaction to determine the cutting range, but this process is time-consuming and inefficient. To overcome this problem, this study proposed a new method for automatically achieving single three-dimensional building model without the need for human-computer interaction. First, the point clouds of an oblique photography model are divided into virtual grids, and the point clouds in each virtual grid are seen as a whole. In this way, the number of point clouds involved in the calculation is reduced, thereby improving computing efficiency. Second, the point clouds of a building facade are extracted by setting the height difference. By comparing the height difference between the highest point and the lowest point of the grid with height difference threshold, all point clouds in the grid that do not meet the requirements are eliminated. Third, the point clouds of the building facade are classified, and the contour line is extracted by the classified point clouds. Finally, the single three-dimensional building model is achieved by reconstructing the triangles that intersect with the extracted contour line. Experimental results show that the proposed method can effectively achieve single bodies automatically from an oblique photography building model. This method is then useful for achieving single three-dimensional building model from massive oblique photography data.

Mathematical Principles of Object 3D Reconstruction by Shape-from-Focus Methods

Shape-from-Focus (SFF) methods have been developed for about twenty years. They able to obtain the shape of 3D objects from a series of partially focused images. The plane to which the microscope or camera is focused intersects the 3D object in a contour line. Due to wave properties of light and due to finite resolution of the output device, the image can be considered as sharp not only on this contour line, but also in a certain interval of height—the zone of sharpness. SSFs are able to identify these focused parts to compose a fully focused 2D image and to reconstruct a 3D profile of the surface to be observed.

DEM study of the angle of repose and porosity distribution of cylindrical particles with different lengths

Effect of the length of cylindrical particle on repose angle and porosity of a pile was numerically studied using discrete element method. The variation of repose angle and porosity with coefficient of sliding and rolling friction were also discussed. The results shown that compared with sphere particle, the bottom size of cylindrical pile is smaller, while the height of cylinder pile is larger and the heap is steeper. With the increase of the length of cylinder, the contour line of the pile becomes steep, and the angle of repose increases. The repose angle shows a positive correlation with coefficient of sliding and rolling friction. The porosity increases with the increase of the length of cylinders. The trends of porosity are basically consist with that of repose angle, and with increase of friction coefficient, the average porosity increases.

Automated Tool Path Generation for End-Milling Operation Using CAD Model in STL Format

A method to extract the machining region from 3D CAD model in STL (Standard Triangulated Language) format and automatically generate tool path is proposed. At first, this study proposes a method to extract the machining region and obtain the geometrical feature such as convex shape or concave shape from only the 3D CAD model in STL format. The STL format has only triangular mesh data and drops all the information which is necessary to extract the removal volume for machining and the geometrical characteristics. Furthermore, the triangular mesh size is non-uniform. Then, the contour line model, in which the product model is minutely divided on the plane along any one axial direction and represented by points at intervals below the indicated resolution obtained from the contour line of the cross section of the product, is proposed. Subsequently, this study proposes a method to determine the machining conditions for each extracted machining region and automatically generate tool path according to the obtained geometrical feature of the machining region.

Automated Process Planning System for End-Milling Operation by CAD Model in STL Format

A method for extracting the machining region from a 3D CAD model in Standard Triangulated Language (STL) format and automatically generating a tool path is proposed. First, a method is proposed for extracting the machining region and obtaining the geometrical features such as a convex or concave shape from only the 3D CAD model in STL format. The STL format uses only triangular mesh data and drops all information, which is necessary for extracting the removal volume for the machining and geometrical characteristics. Furthermore, the triangular mesh size is non-uniform. A contour line model is proposed in which the product model is minutely divided on the plane along any one axial direction and is represented by points at intervals below the indicated resolution obtained from the contour line of the cross section of the product. Subsequently, a method is proposed to determine the machining conditions for each extracted machining region and automatically generate a tool path according to the geometrical features of the machining region obtained. A machining experiment was conducted to validate the effectiveness of the proposed method. As a result of the machining experiment, it was confirmed that the tool path automatically generated from the 3D CAD model in STL format can be machined without any problems and with a practical level of accuracy.