Computer-aided Design Applications Research Articles

Simulation of postoperative occlusion and direction in autotransplantation of teeth: application of computer-aided design and digital surgical templates

Autotransplantation of teeth requires optimisation of both occlusion and direction to ensure minimal injury to the dental crown and the alveolar bone. We describe a method that could simulate postoperative occlusion and direction of the donor tooth by using CAD and digital surgical templates, and evaluate the postoperative effect in five patients who had teeth autotransplanted. Computed tomographic data were imported into ProPlan CMF 3.0 software, the donor tooth was simulated to replace the recipient site according to the position of the occlusion and alveolar bone, and a digital template was designed to guide preparation of the socket. A computer-aided, rapid prototyped, tooth was used to match the socket and, finally, an occlusal template was designed to ensure that the donor tooth was in the simulated position. We compared the position of the tooth in the simulation with its postoperative position using ProPlan CMF 3.0 software. In this way it was possible to simulate and guide the donor tooth accurately to the recipient site. At six-month follow up all teeth had survived successfully. Given the efficiency and precision of placement and the success, we conclude that CAD can successfully help to simulate occlusion and direction in autotransplantation of teeth while simplifying the procedure.

Application of 3D Visualization in Landscape Design Teaching

The development of computer technology has reshaped the form and philosophy of landscape design, as evidenced by the growing importance of computer-aided design (CAD) in this area. This paper attempts to apply 3D visualization in the teaching of landscape design. For this purpose, three CAD teaching tools were selected, namely, AutoCAD, 3D Max and SketchUp, and subjected to theoretical analysis and teaching practice. The research results show that AutoCAD can guide the landscape design teaching from conception to positioning, 3D Max can upgrade the teaching form from 2D to 3D in the later phase, and SketchUp sup-ports the entire process of landscape design. In addition, the author summarized the specific process of supporting landscape design teaching with SketchUp. This research enriches the results on the application of CAD in landscape design teaching and has certain theoretical and practical significance.

The Pharmacophore Concept and Its Applications in Computer-Aided Drug Design.

Pharmacophore-based techniques currently are an integral part of many computer-aided drug design workflows and have been successfully and extensively applied for tasks such as virtual screening, de novo design, and lead optimization. Pharmacophore models can be derived both in a receptor-based and in a ligand-based manner, and provide an abstract description of essential non-bonded interactions that typically occur between small-molecule ligands and macromolecular targets. Due to their simplistic and abstract nature, pharmacophores are both perfectly suited for efficient computer processing and easy to comprehend by life and physical scientists. As a consequence, they have also proven to be a valuable tool for communicating between computational and medicinal chemists.This chapter aims to provide a short overview of the pharmacophore concept and its applications in modern computer-aided drug design. The chapter is divided into three distinct parts. The first section contains a brief introduction to the pharmacophore concept. The second section provides a description of the most common nonbonded interaction types and their representation as pharmacophoric features. Furthermore, it gives an overview of the various methods for pharmacophore generation and important pharmacophore-based techniques in drug design. This part concludes with examples for recent pharmacophore concept-related research and development. The last section is dedicated to a review of research in the field of natural product chemistry as carried out by employing pharmacophore-based drug design methods.

Improving creative self-efficacy and performance through computer-aided design application

This paper discusses the effect of the application of three-dimensional computer-aided design (3D-CAD) on the creative self-efficacy and performance of student designers. A nonequivalent pretest–posttest quasi-experimental design was applied, and 164 students from a high school in Taipei City were sampled. The conclusions are summarized as follows: 1. Low–moderate positive correlations were identified between the total score and individual items of the creative self-efficacy of the students and those of the creative performance of the students. 2. Using 3D-CAD significantly enhanced the creative performance of the students, particularly the usefulness of their products. 3. Using 3D-CAD strengthened the creative self-efficacy of the students, particularly in countering external negative assessment of their creative products with positive beliefs.

Registration of Dental Tomographic Volume Data and Scan Surface Data Using Dynamic Segmentation

Over recent years, computer-aided design (CAD) has become widely used in the dental industry. In dental CAD applications using both volumetric computed tomography (CT) images and 3D optical scanned surface data, the two data sets need to be registered. Previous works have registered volume data and surface data by segmentation. Volume data can be converted to surface data by segmentation and the registration is achieved by the iterative closest point (ICP) method. However, the segmentation needs human input and the results of registration can be poor depending on the segmented surface. Moreover, if the volume data contains metal artifacts, the segmentation process becomes more complex since post-processing is required to remove the metal artifacts, and initially positioning the registration becomes more challenging. To overcome these limitations, we propose a modified iterative closest point (MICP) process, an automatic segmentation method for volume data and surface data. The proposed method uses a bundle of edge points detected along an intensity profile defined by points and normal of surface data. Using this dynamic segmentation, volume data becomes surface data which can be applied to the ICP method. Experimentally, MICP demonstrates fine results compared to the conventional registration method. In addition, the registration can be completed within 10 s if down sampling is applied.

Management of an edentulous patient with temporomandibular disorders by using CAD-CAM prostheses: A clinical report

This clinical report describes the application of computer-aided design and computer-aided manufacturing (CAD-CAM) complete dentures (CDs) in 4 visits and a 2-year follow-up period for a patient with temporomandibular disorders (TMDs), severe occlusal disturbances, and parafunctional habits. The use of a Gothic arch tracing for recording the maxillomandibular relationship and verifying muscular function was particularly helpful in such a symptomatic patient. A trial period was used to determine patient acceptance and adaptation to the new CDs.

Finite element analysis and geometry optimization of a flywheel used in a monorail conveyor

In this work is presented the theoretical aspects for dimensioning calculations, design, and finite element analysis of the drive flywheel of the cable of a monorail conveyor. In order to obtain 3D model and study the behaviour of the drive wheel were used application for computer-aided design (CAD), applications for engineering calculations (CAE), and finite element analysis (FEM). After analyzing the obtained results, it was used a computer program for optimizing the geometry of a flywheel by modifying some geometrical parameters to obtain a minimum weight and the displacements and stress to be within allowable limits. The use of computer offers the possibility to automate engineering calculations ensuring the rapid processing of data and thereby reducing the time and cost of developing a product, in comparison with the traditional way.

The virtual commissioning technology applied in the design process of a flexible automation system

This paper describes an application of the virtual commissioning technology applied to the design of a robotized manufacturing cell. Virtual commissioning requires the integration of different technologies, such as PLC (programmable logic controller) programming, device communication with OPC (OLE for process control), off-line robot programming, HIL (hardware-in-the-loop), as well as the design of devices and tools using computer-aided design (CAD) applications. Within this application, the virtual commissioning resource evaluates the operation of an assembly line, simulates several processes in a digital environment, tests real equipment and tools and integrates a system that shares the signals of the sensors and actuators with the simulation environment in the computer. The case study described herein compares a conventional design process of a car floor spot welding station to the design approach using virtual commissioning. The robotic welding cell is controlled by a PLC integrated in a simulation environment that uses two industrial robots created in the Process Simulate Robotics application of Siemens Tecnomatix®.

Identification of Thiourea-Based Inhibitors of the B-Cell Lymphoma 6 BTB Domain via NMR-Based Fragment Screening and Computer-Aided Drug Design.

Protein-protein interactions (PPI) between the transcriptional repressor B-cell lymphoma 6 (BCL6) BTB domain (BCL6BTB) and its corepressors have emerged as a promising target for anticancer therapeutics. However, identification of potent, drug-like inhibitors of BCL6BTB has remained challenging. Using NMR-based screening of a library of fragment-like small molecules, we have identified a thiourea compound (7CC5) that binds to BCL6BTB. From this hit, the application of computer-aided drug design (CADD), medicinal chemistry, NMR spectroscopy, and X-ray crystallography has yielded an inhibitor, 15f, that demonstrated over 100-fold improved potency for BCL6BTB. This gain in potency was achieved by a unique binding mode that mimics the binding mode of the corepressor SMRT in the aromatic and the HDCH sites. The structure-activity relationship based on these new inhibitors will have a significant impact on the rational design of novel BCL6 inhibitors, facilitating the identification of therapeutics for the treatment of BCL6-dependent tumors.

Touching proteins with virtual bare hands

The ability to precisely visualize the atomic geometry of the interactions between a drug and its protein target in structural models is critical in predicting the correct modifications in previously identified inhibitors to create more effective next generation drugs. It is currently common practice among medicinal chemists while attempting the above to access the information contained in three-dimensional structures by using two-dimensional projections, which can preclude disclosure of useful features. A more accessible and intuitive visualization of the three-dimensional configuration of the atomic geometry in the models can be achieved through the implementation of immersive virtual reality (VR). While bespoke commercial VR suites are available, in this work, we present a freely available software pipeline for visualising protein structures through VR. New consumer hardware, such as the HTC Vive and the Oculus Rift utilized in this study, are available at reasonable prices. As an instructive example, we have combined VR visualization with fast algorithms for simulating intramolecular motions of protein flexibility, in an effort to further improve structure-led drug design by exposing molecular interactions that might be hidden in the less informative static models. This is a paradigmatic test case scenario for many similar applications in computer-aided molecular studies and design.

Knowledge graph construction with structure and parameter learning for indoor scene design

We consider the problem of learning a representation of both spatial relations and dependencies between objects for indoor scene design. We propose a novel knowledge graph framework based on the entity-relation model for representation of facts in indoor scene design, and further develop a weaklysupervised algorithm for extracting the knowledge graph representation from a small dataset using both structure and parameter learning. The proposed framework is flexible, transferable, and readable. We present a variety of computer-aided indoor scene design applications using this representation, to show the usefulness and robustness of the proposed framework.

A competition flow method for computing medial axis transform

Abstract Medial axis computation (MAC) has many applications in computer-aided design, computer graphics, automated mesh generation, solid modeling, CNC tool path generation, robotic motion planning, bioinformatics, and shape analysis. There are three key issues that need to be further addressed on MAC of a NURBS(Non-Uniform Rational B-Spline) curve boundary, namely (1) computation of regular medial axis points; (2) efficient detection of the existence of a branch point where two branches intersect; and (3) convergence and correctness on computing the position of a branch point. This paper presents a competition flow method for medial axis computation of a planar simply-connected NURBS boundary. Different from previous methods which trace a Voronoi Diagram Tree (VDT) in depth-first order from a terminal point, the competition flow method (CFM) traces the corresponding tree in breadth-first order. It has three main contributions. Firstly, it utilizes an optimized method based on previous state-of-art algorithms for computing regular medial axis points, which can achieve a higher computational efficiency. Secondly, it implements a divide-and-conquer method in a natural way by proposing a simple tree technique, in which a VDT is divided into several simple tree structures of level l , l = 0 , 1 , … , for competitive medial axis computation. Finally, by using the competition flow method, possible places where branch points are located, are intuitively and efficiently detected and bounded with high precision, which ensures the convergence and the correctness of the computation of the position of a branch point, and also ensures the correctness of the topological structure of the medial axis tree. Numerical examples show that the new method can achieve a better performance compared with several existing methods.

Inheritance of Traditional Decorations under Computer Aided Design

Development of computer-aided design applications and Traditional Decorations design, software is the core of computer-aided design in Traditional Decoration design, graphic combined with three-dimensional software, building the systematic of Traditional Decorations design and computer-aided design to enhance the artistic beauty of Traditional Decoration design. Secondly, introduce the two-dimensional and three-dimensional software application in fabric pattern and Traditional Decoration design. We can see the convenience of computer-aided design, which combines technology and art in one. And from the comparison of plane and solid software, both proposed to build a systematic mutual, for Traditional Decoration design, which is based on the performance requirements and the effect of artistic design, and the theoretical analysis of consumer purchase intention and behavior; and discussing from the beauty of color, formal and spatial three aspects of computer-aided design to enhance the artistic beauty of Traditional Decoration design.

CAD/CAM technology in implant abutment design

Study of implants has become indispensable and so is the biomechanics related to dental implant therapy. Implant therapy is a fast-growing and brightest prospect in the rehabilitation of completely and partially edentulous arches. The evolution of implants has become a ‘restorative driven ’field, and it is therefore important to know the designing principles of abutments and its connection to the implants and its rationale for use in clinical practice. The key is to have an optimum selection and designing of the implant to meet the implant position and angulations in the clinical scenario. Implant abutment connection is a crucial synapse between the implant and the abutment. It is an important determinant of the strength and stability of an implant supported restoration and plays a major role in the success of the implant. This article highlights designing principles of various abutments and its role in aesthetics and the application of computer-aided design and computer-aided manufacturing to produce implant abutment.

Toward Smart Building Design Automation: Extensible CAD Framework for Indoor Localization Systems Deployment

Over the last years, many smart buildings applications, such as indoor localization or safety systems, have been subject of intense research. Smart environments usually rely on several hardware nodes equipped with sensors, actuators, and communication functionalities. The high level of heterogeneity and the lack of standardization across technologies make design of such environments a very challenging task, as each installation has to be designed manually and performed ad-hoc for the specific building. On the other hand, many different systems show common characteristics, like the strict dependency with the building floor plan, also sharing similar requirements such as a nodes allocation that provides sensing coverage and nodes connectivity. This paper provides a computer-aided design application for the design of smart building systems based on the installation of hardware nodes across the indoor space. The tool provides a site-specific algorithm for cost-effective deployment of wireless localization systems, with the aim to maximize the localization accuracy. Experimental results from real-world environment show that the proposed site-specific model can improve the positioning accuracy of general models from the state-of-the-art. The tool, available open-source, is modular and extensible through plug-ins allowing to model building systems with different requirements.

Review: Grasshopper Algorithmic Modeling for Rhinoceros 5

Grasshopper Algorithmic Modeling for Rhinoceros 5 http://www.grasshopper3d.com It is only since the nineteenth century that we have been able to speak of Western architectural history and design as clearly separate disciplines. To make this distinction, we have had to draw clear borders between the disciplines’ respective methods and practices. This has not always been easy. Historians have long used the tools of design—such as plans, elevations, and diagrams—as part of their analytical tool kit, while architects have used the tropes and techniques of historical formal analysis through diagrams as a projective act of design in its own right. Sometimes the distinction collapses completely. When Rudolf Wittkower published his famous eleven diagrams of known Palladian villas, he included an additional one titled “Geometric Pattern of Palladio's Villas.”1 While each of the eleven original diagrams was congruent with the building plan on which it was based—as if it had been traced—the additional diagram depicted a set of idealized geometric relationships that did not correspond to the footprint of any one villa. This twelfth diagram, freed as it was from reference to a specific historical object, uncomfortably blurred the distinction between historical analysis and design proposition. To complicate this distinction further, architects have sometimes used formal diagrammatic analysis as a generative design method. Peter Eisenman, for example, has used a derivative of Wittkower's twelfth diagram as the starting point for rule-based formal development of a series of houses.2 More recently, architects grappling with a range of new digital tools and techniques have returned to history as a means of grounding their work within the core of the discipline through the digitally mediated formal analysis of precedents. Their tools—primarily the application of computer-aided design and scripting—along with the methods by which they are applied ask us to rethink the role of history in architectural production and offer new techniques …

Recognition and decomposition of rib features in thin-shell plastic parts for finite element analysis

Feature recognition has been extensively studied for applications in computer-aided design (CAD), computer-aided manufacturing, and computer-aided process planning. However, its application in fini...

Application of Computer-Aided Design and Customized Implants in the Reconstruction of Pyriform Aperture Defects Secondary to Unilateral Cleft Lip and Palate.

To design and develop customized implants with the rapid prototyping (RP) technique in order to reconstruct the defected pyriform aperture. A 3-dimensional digital model was reconstructed with the software proplan CMF based on the computed tomography data of the patient's skeleton. Then an individualized implant was designed by computer-aided design (CAD) and prepared with the RP technique. A total of 5 patients (3 males and 2 females) with unilateral secondary nasal deformities received the customized implants in this study. All the implants closely matched the surface of the defects. During the 12- to 24-month follow-up period, all the patients reported satisfactory outcomes except for 1 patient where exposure of the implant was observed and had to be removed 3 months after the surgery. With high precision and matching degree, individualized implants designed by CAD and prepared with the RP technique can be used to overcome the limitations of ready-made materials and improve the accuracy of the surgical procedure in reconstructing the defected pyriform aperture.

Clinical outcomes of patient-specific porous titanium endoprostheses in dogs with tumors of the mandible, radius, or tibia: 12 cases (2013-2016).

OBJECTIVE To characterize the processes involved in and outcomes achieved with custom-designed patient-specific implants to provide functional replacement of skeletal structures in dogs with tumors of the mandible, radius, or tibia. DESIGN Prospective case series. ANIMALS 6 dogs with mandibular tumors, 5 with tumors of the distal aspect of the radius, and 1 with a tumor in the distal aspect of the tibia treated from June 2013 to September 2016 at 3 referral centers. PROCEDURES After tumor staging, implants were designed from patients' CT scans by means of various computer-aided design applications and printed by means of selective laser melting in titanium-6 aluminum-4 vanadium alloy. A cutting jig was created in thermoplastic to ensure each osteotomy was performed as planned. Following ostectomy, the implant was secured into the defect with screws of appropriate size and length. RESULTS Initial return to normal clinical function was good to excellent for 11 of the 12 dogs. However, major complications resulted in revision of the implant or amputation of the limb in 5 dogs, and at least 3 of these complications were considered a consequence of faulty implant design or manufacturing. Infection developed in 2 dogs and was successfully treated in 1 dog. The longest-surviving dog maintained good limb function for 2 years. CONCLUSIONS AND CLINICAL RELEVANCE This is the largest reported series of dogs managed with customized 3-D-printed titanium implants. The 3-D printing allowed complex and patient-specific 3-D geometries to be fabricated, enabling function-sparing treatment of bone cancer affecting multiple anatomic sites.

Computer reconstruction of 19th century trousers

PurposeDesigning of clothes using the historical prototypes is very popular in contemporary practice. The purpose of this paper is to apply 2D and 3D computer-aided design (CAD) systems to reconstruct the historical pattern block and get the virtual image in accordance with the prototypes. New algorithm has been proved for men trousers taken from the nineteenth century.Design/methodology/approachOur approach is to develop a method of CAD to reconstruct historical trousers through analyzing and rebuilding of historical algorithms used to pattern blocks making, old anthropometrical database, and the pattern blocks shaping. Trousers construction, methods of trousers shaping by hands, body sizes schedule, manuals of 36 pattern cutting systems, and its sketches from nineteenth century have been analyzed. Then, by means of parameterization of historical pattern blocks, we have developed the universal trousers pattern cutting algorithm. The final step of the research has been devoted to virtual fitting technology that helps to determine the differences between historical trousers chosen as prototype and virtual image reconstructed by 3D CAD.FindingsThe authors have developed the parametrical module of 2D CAD and expanded the application of 3D CAD to re-designing of completely new object such as nineteenth century trousers pattern blocks in accordance with the historical method of shaping by hands. The conformity between the style of historical trousers and the virtual images reconstructed from two resources – pattern block and sketch silhouette – has been achieved.Originality/valueThis study demonstrated the contemporary approach to historical garments reconstruction by means of CAD. This study should help researchers of historical costume and practical specialists in apparel industry to apply historical heritage in a contemporary way.