scholarly journals A metrological approach for multispectral photogrammetry

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 111
Author(s):  
Leila Es Sebar ◽  
Luca Lombardo ◽  
Marco Parvis ◽  
Emma Angelini ◽  
Alessandro Re ◽  
...  
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Point Of View ◽  
Reference Object ◽  
Dimensional Precision ◽  
Visible Luminescence ◽  
3D Printed ◽  
Metrological Approach ◽  
Metrological Quality

<p>This paper presents the design and development of a three-dimensional reference object for the metrological quality assessment of photogrammetry-based techniques, for application in the cultural heritage field. The reference object was 3D printed, with nominal manufacturing uncertainty of the order of 0.01 mm. The object was realized as a dodecahedron, and in each face, a different pictorial preparation was inserted. The preparations include several pigments, binders, and varnishes, to be representative of the materials and techniques used historically by artists.</p><p>Since the reference object’s shape, size and uncertainty are known, it is possible to use this object as a reference to evaluate the quality of a 3D model from the metric point of view. In particular, verification of dimensional precision and accuracy are performed using the standard deviation on measurements acquired on the reference object and the final 3D model. In addition, the object can be used as a reference for UV-induced Visible Luminescence (UVL) acquisition, being the materials employed UV-fluorescent. Results obtained with visible-reflected and UVL images are presented and discussed.</p>

Algorithm to Reduce Leading and Lagging in Conformal Direct-Print

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
Three Dimensional ◽  
Motion Direction ◽  
B Spline ◽  
And Topology ◽  
Printing System ◽  
3D Printed ◽  
Printed Patterns

A novel additive manufacturing algorithm was developed to increase the consistency of three-dimensional (3D) printed curvilinear or conformal patterns on freeform surfaces. The algorithm dynamically and locally compensates the nozzle location with respect to the pattern geometry, motion direction, and topology of the substrate to minimize lagging or leading during conformal printing. The printing algorithm was implemented in an existing 3D printing system that consists of an extrusion-based dispensing module and an XYZ-stage. A dispensing head is fixed on a Z-axis and moves vertically, while the substrate is installed on an XY-stage and moves in the x–y plane. The printing algorithm approximates the printed pattern using nonuniform rational B-spline (NURBS) curves translated directly from a 3D model. Results showed that the proposed printing algorithm increases the consistency in the width of the printed patterns. It is envisioned that the proposed algorithm can facilitate nonplanar 3D printing using common and commercially available Cartesian-type 3D printing systems.

scholarly journals Students’ Intuitive and Analytical Thinking in the Mathematics Study through the Integration of STAD and Environmental Islamic Jurisprudence (Fiqh)

2020 ◽  
Vol 11 (1) ◽  
pp. 49-60
Author(s):  
Abdillah Abdillah ◽  
Ajeng Gelora Mastuti ◽  
Muhammad Rijal ◽  
Muhajir Abd. Rahman
Keyword(s):  
Learning Process ◽  
Mathematical Problem ◽  
Three Dimensional ◽  
Point Of View ◽  
Effective Learning ◽  
Intuitive Thinking ◽  
Analytical Thinking ◽  
Research Problems ◽  
Interest And Motivation

The success of a learning process depends on the teacher’s mastery of materials, strategies, and media. Teachers need to possess high creativity to maintain their students’ interest and motivation in learning. The integration of effective learning models and appropriate media, such as using plastic waste as realia, can be one of the alternatives to improve the quality of learning. This study also aimed to examine students' awareness of environmental issues. The quantitative and qualitative data of the study were collected simultaneously to answer the research problems. Interviews were conducted during the implementation of the learning process and quizzes. A pre-experimental one-shot case study design was employed to gather the quantitative data which were then analyzed descriptively. The results of the current study showed that the students' intuitive thinking started to develop in phase 3, where they were asked to identify the type of plastic glass they were holding. Phase 4 that allowed the students to separate parts constructing the glass, determine the name of each part, and set a point of view or the purpose underlying the material presented was the phase where the students performed an analytical thinking process. In phase 5, the students were allowed to solve a mathematical problem using analytical thinking. The interaction between students' intuitive and analytical thinking shown in the identification and labeling of each type of three-dimensional form will be discussed in this article  

Effect of 3D Manipulatives on Students with Visual Impairments Who Are Learning Chemistry Constructs: A Pilot Study

2020 ◽  
Vol 114 (5) ◽  
pp. 370-381
Author(s):  
Derrick W. Smith ◽  
Sandra A. Lampley ◽  
Bob Dolan ◽  
Greg Williams ◽  
David Schleppenbach ◽  
...  
Keyword(s):  
Stem Education ◽  
3D Model ◽  
Atomic Orbital ◽  
Visual Impairments ◽  
Three Dimensional ◽  
3D Models ◽  
Specific Content ◽  
3D Printed ◽  
Printed Materials ◽  
Tactile Graphics

Introduction: The emerging technology of three-dimensional (3D) printing has the potential to provide unique 3D modeling to support specific content in science, technology, engineering, and mathematics (STEM) education, particularly chemistry. Method: Seventeen ( n = 17) students with visual impairments were provided direct instruction on chemistry atomic orbital content and allowed to use either print or tactile graphics or 3D models in rotating order. Participants were asked specific content questions based upon the atomic orbitals. Results: The students were asked two sets of comprehension questions: general and specific. Overall, students’ responses for general questions increased per iteration regardless of which manipulative was used. For specific questions, the students answered more questions correctly when using the 3D model regardless of order. When asked about their perceptions toward the manipulatives, the students preferred the 3D model over print or tactile graphics. Discussion: The findings show the potential for 3D printed materials in learning complex STEM content. Although the students preferred the 3D models, they all mentioned that a combination of manipulatives helped them better understand the material. Implications for practitioners: Practitioners should consider the use of manipulatives that include 3D printed materials to support STEM education.

scholarly journals Modeling in AUTOCAD for bachelors

2021 ◽  
pp. 25-28
Author(s):  
Л.В. Карпюк ◽  
Н.О. Давіденко
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Model Space ◽  
Educational Process ◽  
Point Of View ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Three Dimensional Objects ◽  
Graphic Editor

The article discusses the methods of using the AutoCad graphic editor for creating three-dimensional objects. The possibilities of three-dimensional modeling in the AutoCad graphic editor for optimizing the educational process of bachelors of technical specialties are also considered. The article analyzes the best ways to create mechanical engineering drawings.The most developed software tool for the production of design documentation is AutoCAD - a universal graphic design system. Creating models of any complexity in space by using this graphic editor, the user will be able to see their relative position, estimate the distance between them. The model can be freely moved in space, viewing many options. The ability to control the point of view allows to conveniently select the view of the 3D model that is being developed. Zooming, panning in real time with the ability to freely rotate the camera around the model provide the ability to quickly view objects from any point of view. The article provides examples of choosing the most optimal option for creating a three-dimensional model. The traditional way to create a 3D model drawing is to make 2D views of the model. When creating a flat drawing, there is a possibility of error when making projections, since they are created independently from each other and consist of several images. It is rather difficult to represent an object in space from a flat drawing. At present, modern software graphic editors are aimed at creating three-dimensional models that allow to create realistic models and, on their basis, get two-dimensional projections. Graphic editor AutoCad allows to create three-dimensional objects based on standard commands, in the form of a cylinder, cone, box, torus, etc., when editing which you can get the desired shapes. After creating a three-dimensional model, the user can get its two-dimensional projections not only on the main planes, but also on any plane at will. The 3D modeling method allows you to create a complex drawing with any number of images based on a 3D model. There are ways to create 2D plane drawings from a 3D model and the ability to edit ready-made designs that can be inserted from model space into paper space. Editing takes place by changing the parameters of a 3D object in model space, and these changes are automatically reflected in paper space. This method allows us to use the tools to quickly create a system of 3-4 linked views for a 3D AutoCad model.

scholarly journals Problems of Creation and Usage of 3D Model of Structures and Theirs Possible Solution

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 181 ◽  
Author(s):  
Dalibor Bartonek ◽  
Michal Buday
Keyword(s):  
Computer Aided Design ◽  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
Cad System ◽  
Building Models ◽  
Special Cad ◽  
Aided Design ◽  
The Church

This article describes problems that occur when creating three-dimensional (3D) building models. The first problem is geometric accuracy; the next is the quality of visualization of the resulting model. The main cause of this situation is that current Computer-Aided Design (CAD) software does not have sufficient means to precision mapping the measured data of a given object in field. Therefore the process of 3D model creation is mainly a relatively high proportion of manual work when connecting individual points, approximating curves and surfaces, or laying textures on surfaces. In some cases, it is necessary to generalize the model in the CAD system, which degrades the accuracy and quality of field data. The article analyzes these problems and then recommends several variants for their solution. There are described two basic methods: using topological codes in the list of coordinates points and creating new special CAD features while using Python scripts. These problems are demonstrated on examples of 3D models in practice. These are mainly historical buildings in different locations and different designs (brick or wooden structures). These are four sacral buildings in the Czech Republic (CR): the church of saints Johns of Brno-Bystrc, the Church of St. Paraskiva in Blansko, further the Strejc’s Church in Židlochovice, and Church of St. Peter in Alcantara in Karviná city. All of the buildings were geodetically surveyed by terrestrial method while using total station. The 3D model was created in both cases in the program AUTOCAD v. 18 and MicroStation.

scholarly journals Three-Dimensional Bioprinting and Its Potential in the Field of Articular Cartilage Regeneration

Cartilage ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 327-340 ◽  
Author(s):  
Vivian H. M. Mouser ◽  
Riccardo Levato ◽  
Lawrence J. Bonassar ◽  
Darryl D. D’Lima ◽  
Daniel A. Grande ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Three Dimensional ◽  
Cartilage Regeneration ◽  
Biologically Active ◽  
3D Bioprinting ◽  
Clinical Images ◽  
3D Printed ◽  
Current Article ◽  
Hybrid Printing

Three-dimensional (3D) bioprinting techniques can be used for the fabrication of personalized, regenerative constructs for tissue repair. The current article provides insight into the potential and opportunities of 3D bioprinting for the fabrication of cartilage regenerative constructs. Although 3D printing is already used in the orthopedic clinic, the shift toward 3D bioprinting has not yet occurred. We believe that this shift will provide an important step forward in the field of cartilage regeneration. Three-dimensional bioprinting techniques allow incorporation of cells and biological cues during the manufacturing process, to generate biologically active implants. The outer shape of the construct can be personalized based on clinical images of the patient’s defect. Additionally, by printing with multiple bio-inks, osteochondral or zonally organized constructs can be generated. Relevant mechanical properties can be obtained by hybrid printing with thermoplastic polymers and hydrogels, as well as by the incorporation of electrospun meshes in hydrogels. Finally, bioprinting techniques contribute to the automation of the implant production process, reducing the infection risk. To prompt the shift from nonliving implants toward living 3D bioprinted cartilage constructs in the clinic, some challenges need to be addressed. The bio-inks and required cartilage construct architecture need to be further optimized. The bio-ink and printing process need to meet the sterility requirements for implantation. Finally, standards are essential to ensure a reproducible quality of the 3D printed constructs. Once these challenges are addressed, 3D bioprinted living articular cartilage implants may find their way into daily clinical practice.

scholarly journals Evaluation of Dimensional Accuracy of 3D printed mandibular model using two different Additive Manufacturing Techniques based on Ultra-Low Dose Multislice Computed Tomography scan data

2020 ◽  
Author(s):  
Noran Mohamed Hesham ◽  
Hossam Kandel ◽  
Iman Ismail Dakhli
Keyword(s):  
3D Model ◽  
Dimensional Accuracy ◽  
Diagnostic Accuracy Study ◽  
Operative Planning ◽  
Accuracy Study ◽  
3D Printers ◽  
3D Printed ◽  
Manufacturing Techniques ◽  
Dental Applications

Abstract Article Type : Research article Corrective and reconstructive cranio-maxillofacial interventions are a challenging area of surgery that requires careful pre-operative planning. To accommodate the need for precision pre-operative planning, surgeons frequently need guidance such as a 3D model to display complex cranial structures. 3D model is a manufactured model made by a 3D printer using digital imaging and communication for medicine (DICOM) data from a CT scan, and then, converted into computer-assisted design (CAD) data. Image acquisition is a very important step in generation of 3D objects as the quality of the object depends on the quality of the data. MSCT is widely applied for rapid prototyping because image post-processing is less complex for MSCT data.This aim of the present study is to evaluate the dimensional accuracy of the 3D printed mandibular models fabricated by two different additive manufacturing techniques using highly precise one as selective laser sintering (SLS) and low-cost one as fused filament fabrication and whether they are both comparable in terms of precision.In this diagnostic accuracy study , 7 mandibular models will be recruited for the study, 10 linear measurements will be determined on the models. MSCT scanning of the model will be performed. afterwards 3d printing of the scanned image will be done using SLS and FFF 3d printers. the predetermined 10 linear measurement will be measured on the printed models to be compared with the reference standard measurement to determine the accuracy of the 3d printers in dental applications like surgical guides, orthodontic appliances, fixed prosthodontics appliances and other many dental applications. The study is scheduled to be done by october 2020Article Type : Protocol for diagnostic accuracy study

scholarly journals 3D-Printed Model Enhances Learning Experience in Optometric Education

2019 ◽  
Vol 8 (9S3) ◽  
pp. 1355-1359
Keyword(s):  
Confidence Level ◽  
3D Model ◽  
Learning Experience ◽  
Three Dimensional ◽  
Learning Session ◽  
Traditional Lecture ◽  
Teaching Aid ◽  
3D Printed ◽  
Second Year ◽  
Optometry Students

Three-dimensional (3D) printed model becomes more popular as the flexibility to print 3D model has become cheaper to produce. This research sought to assess the effect of using 3D printed model as a tool in teaching on optometry students. Another primary focus of this research was to assess the confidence level and enjoyment level among the second-year optometry students on traditional lecture method and compared it with the use of 3D printed model as a teaching aid. Confidence is important as an optometrist, especially when making the right clinical judgement. Enjoyment is also important as it may help learning process become effective and fast. A total of 36 second-year optometry students were selected to participate in this research. The 3D printed model was based on ophthalmoscope that had been printed using PRUSA 3000 3D printer. The students were divided into two groups – one group was exposed to the lecture only and another group was exposed to 3D model in addition to the traditional lecture. Two sets of questionnaires were given to assess their confidence and enjoyment level before and after each learning session. The confidence level assessment and the enjoyment level comprise of three statements on each topic answered by the students using 5-point Likert scale. The results showed that there are significance differences between lecture only group and lecture with 3D-printed model group especially as a visualization tool (P = 0.001) and it is considered to be enjoyable and stimulating (P = 0.008). This study demonstrates that the usage of 3D printed model as teaching aid does affect the confidence level and enjoyment level of students

scholarly journals The Fabrication of Non-Implant 3D Printed Nose

2018 ◽  
Vol 152 ◽  
pp. 02003
Author(s):  
Yong Leng Chuan ◽  
Elliot Andrews
Keyword(s):  
Human Skin ◽  
3D Model ◽  
Three Dimensional ◽  
Northern European ◽  
Polygon Mesh ◽  
Strength Tests ◽  
Printing Technique ◽  
3D Printed ◽  
Gel Composition ◽  
The Ideal

Non-surgical rhinoplasty procedures which involves the use of injectable derma fillers are highly risky as patients are susceptible to side effects and complications that may cause unwanted changes in their appearance. This research explores an alternative method of non-surgical rhinoplasty for patients seeking augmentation of the nose with the use of three-dimensional (3D) printing. Most rhinoplasty procedures are conducted with the intention of enhancing the aesthetical features of the nose, a 3D model nose was designed based on the combination of the average and the ideal aesthetic parameters of the Northern European Caucasians and South Asia Chinese nose. The modelling of nose is done using the SolidWorks CAD software. An initial design was sketched in a polygon mesh form and further improved on. Different printing materials and infill densities were compared to determine the suitable printing technique. The final nose model is then printed using the Ultimaker 3D printer using Polylactic acid (PLA) with an infill density of 100% at a thickness of 1.4 mm. An inner layer to the 3D printed nose was developed for comfortable attachment of the nose model to human skin. The inner layer was fabricated using agar gelatine. Experiments were carried out to increase the strength and adhesiveness of the gelatine so that it could adhere to the human skin and the PLA surface. Tensile and adhesive strength tests were carried out to determine the suitable gel composition for the attachment of the nose to the user’s face. The key outcome from the experiments using natural gelatine was capability of gel to act as an inner layer for the temporary attachment of the 3D nose model to the human skin

3D Reconstruction Role in Surgical Treatment of Sinonasal Tumours

2018 ◽  
Vol 69 (6) ◽  
pp. 1455-1457
Author(s):  
Dragos Octavian Palade ◽  
Bogdan Mihail Cobzeanu ◽  
Petronela Zaharia ◽  
Marius Dabija
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Patient Specific ◽  
Three Dimensional Printing ◽  
Great Progress ◽  
3D Printed ◽  
Medical Modeling ◽  
Dimensional Printing ◽  
Tissue Defects

Three-dimensional printing has numerous applications and has gained much interest in the medical world. The constantly improving quality of 3D-printing applications has contributed to their increased use on patients. Nowadays, 3D printing is very well integrated in the surgical practice and research. Also, the field of head and neck reconstructive surgery is constantly evolving because of the three-dimensional printing, a technology which can be widely used in a variety of situations such as reconstruction of tissue defects, surgical planning, medical modeling and prosthesis. By using 3D printing into tissue engineering and materials, it may be possible for otolaryngologists to implant 3D printed functional grafts into patients and will also provide a rapid production of personalized patient-specific devices. Advances in 3D printed implants and future tissue-engineered constructs will bring great progress to the field of otorhinolaryngology.

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