Mutual Support and Usage of CAD Systems

2016 ◽  
Vol 4 (2) ◽  
pp. 64-69
Author(s):  
Овчаренко ◽  
O. Ovcharenko

In speaking of modern higher education, we mean an educational system that allows young specialists to fit into the labour market. Such specialists need to be equipped with the necessary knowledge and skills not only to perform work on the project, but also to attack the problem creatively. The task of higher school is to provide the necessary set of knowledge and skills that will allow young specialists to work successfully and to be on the march. The language of communication of engineers is drawings. Computer drawings allow reducing the working time considerably in the development, production, remediation, transfer, and retention. Therefore, the ability to use drawing program for working with images is necessary. Despite all the powerful design tools and visualization, a key moment in computer design is the documentation of the product and its design in accordance with accepted standards that is considered to be an integral part of the design process. After the successful development of a 2D environment, the expert can confidently move on to 3D modeling that facilitates the receipt of drawings and models at times and gives you the opportunity to inspect the settings of the virtual model and, if necessary, to improve them significantly. Usage of different CAD-systems for communication engineers- partners is a reality. Therefore it is very useful for a specialist to be able to use different programs. Modern graphic programs (AutoCAD, SolidEdge) have many similar opportunities, but they also have some differences. Knowledge of several drawing programs is necessary and reduces the amount of time for the skills development for usage of each CAD-system is the problem of the future engineer. The article compares two different programs and the possibility of using the both CAD-systems for working with drawings.

2011 ◽  
Vol 493-494 ◽  
pp. 594-598
Author(s):  
G. Akgungor ◽  
Y. Olcer ◽  
D. Şen ◽  
B. Tunçelli

The occlusal design of dental restorations should stay in harmonic relation to the remaining dentition. In CAD/CAM dentistry, the occlusion is generated by the CAD software based on standard morphologies from the dental database. An automated adaptation process of this standard morphology to an individual clinical situation is difficult and leading to manual adaptation of the proposal with design tools. The new biogeneric software of the chairside CAD/CAD system (CEREC) automatically collects optic measurement of the preparation side including mesial and distal neighbor teeth and antagonist teeth to design a restoration with a patient specific occlusal morphology. This clinical report demonstrated a case, which was treated with ceramic onlay designed and milled with CEREC system used in biogeneric design mode. Digital impression of the preparation was taken with the intraoral camera. Buccal scan,technique was used for taking the occlusal record. Preparation and antagonist images were automatically correlated by software and a virtual articulator was created. After trimming the virtual model, preparation margins were outlined with the automatic margin finder option of the software and then the insertion axis of the restoration was determined. The biogeneric restoration proposal was then automatically seated to the virtual model and desired changes were performed with the design tools of the software. The restoration was milled from feldspathic ceramic block.


Author(s):  
V. A. Martynyuk ◽  
V. A. Trudonoshin ◽  
V. G. Fedoruk

The article considers applications of foreign CAD-systems in creating the challenging projects at domestic enterprises and design bureaus. As stated in the article "... presently, there is no domestic CAD-system that could completely replace such foreign products as NX, CATIA, Credo". Besides, due to international cooperation in creating the challenging projects (for example, the project to create a modern wide-body aircraft, proposed jointly with China), it makes sense to use the worldwide known and popular CAD systems (the aforementioned NX, CATIA, Credo). Therefore, in the foreseeable future, we will still have to use foreign software products. Of course, there always remains a question of the reliability of the results obtained. Actually, this question is always open regardless of what software product is used - domestic or foreign. This question has been haunting both developers and users of CAD systems for the last 30 to 40 years. But with using domestic systems, it is much easier to identify the cause of inaccurate results and correct the mathematical models used, the methods of numerical integration applied, and the solution of systems of nonlinear algebraic systems. Everything is much more complicated if we use a foreign software product. All advertising conversations that there is a tool to make the detected errors available to the developers, remain only conversations in the real world. It is easily understandable to domestic users, and, especially, to domestic developers of similar software products. The existing development rates and competition for potential buyers dictate a rigid framework of deadlines for releasing all new versions of the product and introducing the latest developments into commercial product, etc. As a result, the known errors migrate from version to version, and many users have accepted it long ago. Especially, this concerns the less popular tools rather than the most popular applications (modules) of a CAD system. For example, in CAD systems, the "Modeling" module where geometric models of designed parts and assembly units are created has been repeatedly crosschecked. But most of the errors are hidden in applications related to the design of parts from sheet material and to the pipeline design, as well as in applications related to the analysis of moving mechanisms and to the strength or gas dynamic analysis by the finite element method.The article gives a concrete example of a moving mechanism in the analysis of which an error was detected using the mathematical model of external influence (a source of speed) in the NX 10.0 system of Siemens.


2021 ◽  
Vol 22 (18) ◽  
pp. 9697
Author(s):  
Huizhong Liu ◽  
Yu Zhang ◽  
Yingsi Wang ◽  
Xiaobao Xie ◽  
Qingshan Shi

Heavy metal pollution is widespread and persistent, and causes serious harm to the environment. Pseudomonas putida, a representative environmental microorganism, has strong resistance to heavy metals due to its multiple efflux systems. Although the functions of many efflux systems have been well-studied, the relationship between them remains unclear. Here, the relationship between the Czc and Cad systems that are predominantly responsible for cadmium efflux in P. putida KT2440 is identified. The results demonstrated that CzcR3, the response regulator of two-component system CzcRS3 in the Czc system, activates the expression of efflux pump genes czcCBA1 and czcCBA2 by directly binding to their promoters, thereby helping the strain resist cadmium stress. CzcR3 can also bind to its own promoter, but it has only a weak regulatory effect. The high-level expression of czcRS3 needs to be induced by Cd2+, and this relies on the regulation of CadR, a key regulator in the Cad system, which showed affinity to czcRS3 promoter. Our study indicates that the Cad system is involved in the regulation of the Czc system, and this relationship is important for maintaining the considerable resistance to cadmium in P. putida.


2021 ◽  
Vol 21 (S1) ◽  
Author(s):  
Giacomo Donato Cascarano ◽  
Francesco Saverio Debitonto ◽  
Ruggero Lemma ◽  
Antonio Brunetti ◽  
Domenico Buongiorno ◽  
...  

Abstract Background Computer-aided diagnosis (CAD) systems based on medical images could support physicians in the decision-making process. During the last decades, researchers have proposed CAD systems in several medical domains achieving promising results. CAD systems play an important role in digital pathology supporting pathologists in analyzing biopsy slides by means of standardized and objective workflows. In the proposed work, we designed and tested a novel CAD system module based on image processing techniques and machine learning, whose objective was to classify the condition affecting renal corpuscles (glomeruli) between sclerotic and non-sclerotic. Such discrimination is useful for the biopsy slides evaluation performed by pathologists. Results We collected 26 digital slides taken from the kidneys of 19 donors with Periodic Acid-Schiff staining. Expert pathologists have conducted the slides preparation, digital acquisition and glomeruli annotations. Before setting the classifiers, we evaluated several feature extraction techniques from the annotated regions. Then, a feature reduction procedure followed by a shallow artificial neural network allowed discriminating between the glomeruli classes. We evaluated the workflow considering an independent dataset (i.e., processing images not used in the training procedure). Ten independent runs of the training algorithm, and evaluation, allowed achieving MCC and Accuracy of 0.95 (± 0.01) and 0.99 (standard deviation < 0.00), respectively. We also obtained good precision (0.9844 ± 0.0111) and recall (0.9310 ± 0.0153). Conclusions Results on the test set confirm that the proposed workflow is consistent and reliable for the investigated domain, and it can support the clinical practice of discriminating the two classes of glomeruli. Analyses on misclassifications show that the involved images are usually affected by staining artefacts or present partial sections due to slice preparation and staining processes. In clinical practice, however, pathologists discard images showing such artefacts.


Author(s):  
Shuichi Fukuda ◽  
Daisuke Suzuki

Abstract We developed a new CAD tool with special attention paid to rapid prototyping. Most of the present 3-D CAD systems treat geometry with very high accuracy but it is not easy to define or modify geometry as we do in the earlier stages of design. The present CAD systems, we believe, are more oritented toward the detailed design and manufacturing of the final product. As rapid prototyping itself is intended for the earlier stages of design, such a CAD system that permitts more easy or rough definition and modification of geometry is really desired. Most of the rapid prototyping systems generate 3-D geometry by piling up the 2-D sections layer by layer. So, if we develop such a layer-based CAD system, then we could more easily tranfer CAD data to the prototyping system. Such an idea was very old, but the traditional ones cannot manipulate geometry with much ease. What we aimed here is to develop a system that a designer can manipuate geometry as freely as he or she wishes. Thus, our system serves as a preprocessor to the present 3-D CAD systems. We are developing another system which permits to generate 3-D geometry as freely as if we are drawing it using a pen, based on the technology of 3-D measurement device. Couled with this system, the system we are proposing here is expected to tranfer such a 3-D geometry data very rapidly and easily to the prototyping equipment and also can interactively modify thus defined geometry data.


Author(s):  
Olga Ovcharenko
Keyword(s):  

Usage of different CAD systems for engineers is a true reality, therefore it is very useful for a specialist to be able to use different programs. Modern graphic programs (AutoCAD, SolidEdge) do have many similar opportunities but they also contain some very specific dissimilarities. It is necessary to be able to use several of those programs however it could be a problem for a future engineer to be able to find enough time to be able to get familiar with all CAD programs out there. In the article are compare functions of two different graphic programs and look at the possibility of usage both CAD systems to work with drawings.


Author(s):  
Syed Jamal Safdar Gardezi ◽  
Mohamed Meselhy Eltoukhy ◽  
Ibrahima Faye

Breast cancer is one of the leading causes of death in women worldwide. Early detection is the key to reduce the mortality rates. Mammography screening has proven to be one of the effective tools for diagnosis of breast cancer. Computer aided diagnosis (CAD) system is a fast, reliable, and cost-effective tool in assisting the radiologists/physicians for diagnosis of breast cancer. CAD systems play an increasingly important role in the clinics by providing a second opinion. Clinical trials have shown that CAD systems have improved the accuracy of breast cancer detection. A typical CAD system involves three major steps i.e. segmentation of suspected lesions, feature extraction and classification of these regions into normal or abnormal class and further into benign or malignant stages. The diagnostics ability of any CAD system is dependent on accurate segmentation, feature extraction techniques and most importantly classification tools that have ability to discriminate the normal tissues from the abnormal tissues. In this chapter we discuss the application of machine learning algorithms e.g. ANN, binary tree, SVM, etc. together with segmentation and feature extraction techniques in a CAD system development. Various methods used in the detection and diagnosis of breast lesions in mammography are reviewed. A brief introduction of machine learning tools, used in diagnosis and their classification performance on various segmentation and feature extraction techniques is presented.


Author(s):  
Xun Xu

One of the key activities in any product design process is to develop a geometric model of the product from the conceptual ideas, which can then be augmented with further engineering information pertaining to the application area. For example, the geometric model of a design may be developed to include material and manufacturing information that can later be used in computer-aided process planning and manufacturing (CAPP/CAM) activities. A geometric model is also a must for any engineering analysis, such as finite elopement analysis (FEA). In mathematic terms, geometric modelling is concerned with defining geometric objects using computational geometry, which is often, represented through computer software or rather a geometric modelling kernel. Geometry may be defined with the help of a wire-frame model, surface model, or solid model. Geometric modelling has now become an integral part of any computer-aided design (CAD) system. In this chapter, various geometric modelling approaches, such as wire-frame, surface, and solid modelling will be discussed. Basic computational geometric methods for defining simple entities such as curves, surfaces, and solids are given. Concepts of parametric, variational, history-based, and history-free CAD systems are explained. These topics are discussed in this opening chapter because (a) CAD was the very first computer-aided technologies developed and (b) its related techniques and methods have been pervasive in the other related subjects like computer-aided manufacturing. This chapter only discusses CAD systems from the application point of view; CAD data formats and data exchange issues are covered in the second chapter.


2020 ◽  
Vol 7 (5) ◽  
pp. 603-614 ◽  
Author(s):  
Mutahar Safdar ◽  
Tahir Abbas Jauhar ◽  
Youngki Kim ◽  
Hanra Lee ◽  
Chiho Noh ◽  
...  

Abstract Feature-based translation of computer-aided design (CAD) models allows designers to preserve the modeling history as a series of modeling operations. Modeling operations or features contain information that is required to modify CAD models to create different variants. Conventional formats, including the standard for the exchange of product model data or the initial graphics exchange specification, cannot preserve design intent and only geometric models can be exchanged. As a result, it is not possible to modify these models after their exchange. Macro-parametric approach (MPA) is a method for exchanging feature-based CAD models among heterogeneous CAD systems. TransCAD, a CAD system for inter-CAD translation, is based on this approach. Translators based on MPA were implemented and tested for exchange between two commercial CAD systems. The issues found during the test rallies are reported and analyzed in this work. MPA can be further extended to remaining features and constraints for exchange between commercial CAD systems.


Author(s):  
Bartholomew O. Nnaji ◽  
Tzong-Shyan Kang

A generalized approach to fast interpretation of objects and their features has so far eluded researchers. In manufacturing, this interpretation can be approached from the vision point of view or from the CAD data perspective. Presently, CAD systems are widely used in several aspects of manufacturing production. It is therefore more efficient to use CAD data for object reasoning in manufacturing, especially when systems will eventually be data driven. Components can be modelled on a CAD system using various modelling techniques and the representation of their geometric information is still CAD system dependent. However, the advent of the Initial Graphics Exchange Specification (IGES) now makes it possible to represent CAD data in a neutral and standard manner.This paper describes a scheme for recognizing and representing features for CAD data extracted using the IGES interface. The concepts developed are based on graph-based feature representation, where features are represented by a set of faces as well as their topological adjacency.Strategies for classifying features and methods of decomposing a complicated feature into several simpler features for recognition purposes are discussed.


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