Fig 5 - uploaded by Ronilson Rocha
Content may be subject to copyright.
Source publication
This paper deals with the problem of estimating cut results for faceted gemstones. The proposed approach applies artificial neural networks for a faceted gemstones analysis tool that could be further developed for incorporation in a computer-aided-design (CAD) context. Basic concepts concerning gemstone processing are introduced and the design of c...
Contexts in source publication
Context 1
... cutting model can be defined through a diagram with the description of all geometric parameters, dimension ratios, quantity of facets, and necessary angles for each facet. Fig. 5 shows an example of a cutting diagram for a round standard brilliant generated by GemCAD software. This specialized software provides an estimation of bril- liance and material utilization for the models considered in this article. Its estimation procedure is based on inverse ray tracing considering the geometry and refraction index ...
Context 2
... between table and width T/W; (iii) dimension ratio between table and length T/L; (iv) dimension ratio between pavilion and width P/W; (v) dimension ratio between crown and width C/W; (vi) dimension ratio between total height (crown height + girdle thickness + pavilion depth) and width H/ W [7,16]. Remark: for round models like this one showed in Fig. 5, W = L and, consequently, T/W = T/L. Tables 1 and 2 present the design parameters values for the studied gem ...
Similar publications
Esse trabalho apresenta um estudo sobre ferramenta computacional para auxílio ao projeto de lapidação de gemas. O material escolhido para o estudo é o quartzo hialino. São apresentados aspectos de desenvolvimento histórico do processamento de gemas e também os diagramas de lapidação e seus principais parâmetros. Para a determinação do grau de efici...
Citations
... The characteristic of a polished gemstone depends on the amount of the light reflected when entered from its top. By the refraction index of gemstone [12], the critical angle is obtained which is primary restriction in the design process of polished gemstone. This critical angle must be followed by the planar facets of polished gemstone. ...
... When this critical angle used for facets of polished gemstone and if it is lower or bigger than the recommended angle, there is dispersion of the incident lights which does not return. It reduces the brightness and results in poor quality of polished gemstone [12]. ...
... (8). Equations (10), (11), (12), (13) are used to check that 3D point is in -plane or not. Equations (14), (16) are used to calculate scale factor in both -plane and -plane. ...
In this paper, a novel method is used for fitting a polished and faceted object which is also called as a gem or diamond in a given rough gemstone using genetic algorithm. The goal of proposed Genetic Algorithm based Multiple Object Fitting algorithm is to maximize the utilization of the volume of rough gemstone by fitting the largest number of polished gemstones inside rough gemstone. One of the most difficult tasks is to fit the number of polished gemstones and positioning of each and every polished gemstone within the rough gemstone in order to minimize the waste. This is an optimization problem that is used to find the position, orientation, and scaling parameters of all the polished gemstones within a given rough gemstone such that the sum of volumes of all polished gemstones is maximized. The major novelty of proposed work is to fit more than one object in a given rough stone. The simulation results demonstrate the efficiency of our proposed algorithm.
... Artificial neural networks are structures inspired by neurobiological studies of the human brain. ANN are powerful tools that can solve and map a lot of complex problems, leading to its application to several areas, like pattern recognition [12], bioinformatics [13], geology [14], materials [15], concrete [16,17], Structural Health Monitoring (SHM) [18,19], among others. The networks easily adapt to different problems, giving satisfactory results at relatively low computational cost. ...
We propose an artificial neural network (ANN) model to predict the CO2 diffusion through the concrete to determine the carbonation depth over time, analyzing the influence of some training algorithm and the network architecture in the ANN learning process. A reliable experimental test database of the non-accelerated test with 278 results of concrete carbonation depth was created from the published literature. It was used to train, test, and validate the model. Altogether, 120 networks had been trained with different characteristics, verifying its performance. In spite of the non-linearity and complexity of the concrete carbonation phenomenon, the proposed ANN model yielded accurate prediction. Results indicate the best training algorithm and the optimum number of neurons in the hidden layer that allows faster ANN training process and generates the most accurate mapping for the concrete carbonation phenomenon. The use of ANN appears as a robust tool easily applied to the study of the concrete carbonation, aiding in decision making in engineering projects focused on durability.
... In related work, the authors did not find research that used a similar title but instead adopted some of the associated prior research as references. The first reference is by Adriano A. Mol and colleagues [21] researched the efficiency of gemstone cutting design for faceted gemstones in Brazil using an Artificial Neural Network. The cutting was based on the interaction of minor materials, the characteristics of materials and polyhedral shapes that are within gemstones. ...
A gemstone is a mineral stone that be formed from the result of geological processes and has a hardness above 7 Mohs. Nowadays, gemstones have become famous in Indonesian society. Many facts concerning the business of gemstone rings, including encouragement by the the central government for the gemstone souvenirs that are given to State guests by the President of Indonesia, gemstone contests and gemstone exhibitions have all contributed to pique the interest of researchers in the subject. This current research is undertaken to create a system that is able to identify three kinds of gemstone, namely, Ruby, Sapphire and Emerald using the Hue Saturation Value (HSV) colour space, image processing techniques and an Artificial Neural Network (ANN) back propagation algorithm by learning from examples. The hue from the HSV colour space of a gemstone will be used by the system for training. In the image processing, the system will crop, resize, convert from RGB to HSV, obtain a Hue colour and extract the colour as a 30x3 matrix. The extracted result will be used to train an ANN consisting of three input layers, three hidden layers and one output layer with targets that have been predetermined. The results of the tests showed a degree of accuracy of 90.66% with 5 times of training and 25 times of testing on any type of gemstone. The result shows that using Artificial Neural Network Back Propagation in identification gemstone types is success, because the accuracy system has a highest percentage.
... Object analysis means classifying objects based on their behavior. Objects can be classified by various techniques, such as matching the pattern [3], [21], system learning and Artificial Neural Networks [22], control comparison and fuzzy logic [23], and others. The Artificial Neural Networks is considered as the best technique, since it can adapt and learn better when environment changes. ...
Movement change beyond the duration of time and the variations of object appearance becomes an interesting topic for research in computer vision. Object behavior can be recognized through movement change on video. During the recognition of object behavior, the target and the trace of an object in a video must be determined in the sequence of frames. To date, the existence of object on a video has been widely used in different areas such as supervision, robotics, agriculture, health, sports, education, and traffic. This research focuses on the field of education by recognizing the movement of Quantum Maki Quran memorization through a video. The purpose of this study is to enhance the existing computer vision technique in detecting the Quantum Maki Quran memorization movement on a video. It combines the Background Subtraction method and Artificial Neural Networks; and evaluates the combination to optimize the system accuracy. Background Subtraction is used as object detection method and Back propagation in Artificial Neural Networks is used as object classification. Nine videos are obtained by three different volunteers. These nine videos are divided into six training and three testing data. The experimental result shows that the percentage of accuracy system is 91.67%. It can be concluded that there are several factors influencing the accuracy, such as video capturing factors, video improvements, the models, feature extraction and parameter definitions during the Artificial Neural Networks training.
... In Mol, L. S. M. Filho, and Rocha (2007) an artificial neural network is proposed to efficiently estimate the parameters for a quartz gemstone to be cut, using two criteria: brilliance and yield. These criteria were evaluated for 62 cut designs. ...
... Gemstones are generally cut and polished to be used in the jewelry industry. This processing of a gemstone is called lapidation and has the goal to raise the added value of the gemstone (Mol, L. S. M. Filho, and Rocha, 2007). There are several cuts that can be used in a colored gemstone, for example round, oval, pear, navette or marquise, rectangular, square, octagonal or emerald cuts, among others. ...
... The main restriction in the design process is the critical angle that the planar facets must follow. This angle is obtained from the refraction index of the material (Mol, L. S. M. Filho, and Rocha, 2007). Figure 3 shows different facet cuts with different critical angles. ...
In this paper we present a genetic algorithm for solving the gemstone cutting problem. The goal of this problem is to find the largest faceted cut design which fits inside a given rough gemstone. We propose a fast algorithm for finding the largest scaling factor of a faceted cut, once its center and orientation angles are given, as well as a real-valued genetic algorithm for finding the cut having the largest volume. Finally we present experimental results obtained using a set of 50 scanned gemstones and compare the results with similar ones from the literature.
This paper introduces some considerations regarding the geometric principles that lead the configuration of precious gems. Geometry crosses and characterises different aspects of precious gems: from the atomic composition of its raw structure, to the classification of the crystalline system, up to defining shapes and configurations of possible cuts, as well as to control the functioning of the instruments that allow its execution. From age to age, geometry is leading the lapidary art that bases its foundations and rules on it, mainly in order to cut and manufacture the stones, and also to identify the rules that could enhance the brightness or minimize the wastefulness of precious material during the processing. Starting from research still in progress by the authors, this paper will outline the role of geometry in the fields of crystallographic classification, the cuts classification, the methods for design and execution, also through the conspicuous iconography and the digital modelling.
Counting is an important part of gems trade, especially in large quantities. To develop a fast and automatic method for gems counting is necessary. According to the structure of round brilliant cut gem and the typical set property, typical gems were defined by high circularity and probability. Using the characters of typical gems and the relationship between number and area, gems were counted adaptively. The experiments were shown that the processing speed was fast and the accuracy of counting was high enough for large number of gems trading.
