Intelligent critiquing and tutoring of spatial reasoning skills

1996 ◽  
Vol 10 (3) ◽  
pp. 235-249 ◽  
Author(s):  
Ole Jakob Mengshoel ◽  
Sanjeev Chauhan ◽  
Yong Se Kim
Keyword(s):  
Engineering Students ◽  
Spatial Reasoning ◽  
Graph Matching ◽  
Three Dimensional ◽  
Partial Solution ◽  
Instructional Software ◽  
Preliminary Evaluation ◽  
Software System ◽  
Solid Objects ◽  
3D Solid

AbstractThe ability to reason spatially is an important skill required for engineers, particularly in engineering design and construction. One aspect of spatial reasoning is visualizing and constructing three-dimensional (3D) solid objects from two-dimensional (2D) projections. To assist in teaching this to engineering students, an instructional software system is being developed at the University of Illinois. This instructional software system is comprised of the Visual Sweeper and the Visual Teacher. The Visual Sweeper is a geometric framework for solving missing view problems. In missing view problems, students create 3D solid objects from two 2D projections by applying operations inverse to orthographic projection. The Visual Teacher, which is the focus of this article, is an intelligent critiquing and tutoring module that gives feedback to the student regarding partial solutions to missing view problems. The Visual Teacher is comprised of a Recognizer and a Critiquer. The Recognizer identifies which solution solid the student's partial solution is closest to. Based on the solution solid and a student's partial solution, the Criti-quer gives critique and advice to the student. The Recognizer is based on an algorithm for bipartite graph matching, while the Critiquer uses a rule-based approach. This paper describes the Visual Teacher, gives examples of how it can be used, presents preliminary evaluation results, and discusses the system's assumptions and limitations.

Research and Development of Post-Process Software System Based on 3D Solid Model for New Type Residence Structure

2011 ◽  
Vol 243-249 ◽  
pp. 6192-6196
Author(s):  
Zhi Guo Chang
Keyword(s):  
Binary Data ◽  
Three Dimensional ◽  
Solid Model ◽  
Rural Residence ◽  
Software System ◽  
Geometric Information ◽  
Post Process ◽  
Data Output ◽  
New Type ◽  
3D Solid

In the paper, some difficulties and their solutions, about drawings, detailed drawings and CNC data output based on three-dimensional solid model for various forms of rural residence structures, are discussed. The complex spatial relationships and construction details can be shown directly, accurately and completely in drawings software system based on 3D solid model. Therefore, drawings and detailed drawings can be drawn and labeled automatically by projecting and hiding with the extracted geometric information of particular entities. Further more, in the software system, Manufacture information of components and parts in the 3D Solid model can be extracted and CNC data can be outputted with according to the required format, such as: the binary data, Excel tables, and so on.

Facilitating 3D Virtual World Learning Environments Creation by Non-Technical End Users through Template-Based Virtual World Instantiation

2013 ◽  
Vol 4 (1) ◽  
pp. 32-48 ◽  
Author(s):  
Chang Liu ◽  
Ying Zhong ◽  
Sertac Ozercan ◽  
Qing Zhu
Keyword(s):  
Learning Environments ◽  
Virtual Worlds ◽  
Virtual World ◽  
Three Dimensional ◽  
End Users ◽  
Preliminary Evaluation ◽  
3D Design ◽  
Domain Specific ◽  
Functional Learning ◽  
Preliminary Experimental Data

This paper presents a template-based solution to overcome technical barriers non-technical computer end users face when developing functional learning environments in three-dimensional virtual worlds (3DVW). iVirtualWorld, a prototype of a platform-independent 3DVW creation tool that implements the proposed solution, facilitates 3DVW learning environment creation through semantics-based abstract 3DVW representation and template-based 3DVW instantiation. iVirtualWorld provides a wizard to guide the 3DVW creation process, and hide low-level programming and 3D design details through higher-level abstracts supported by pre-defined templates. Preliminary evaluation of the effectiveness of iVirtualWorld showed positive results. The contribution of this study is threefold: 1) It provides a paradigm for investigating and developing 3DVW building tools from end users’ perspective; 2) It develops a prototype of a 3DVW building tool, which gives educators a framework to easily create educational virtual worlds using domain-specific concepts; 3) It conducts empirical research and collected preliminary experimental data for evaluation.

Distributed-Parameter Modeling for Geometry Control of Manufacturing Processes With Material Deposition

1998 ◽  
Vol 122 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Charalabos Doumanidis ◽  
Eleni Skordeli
Keyword(s):  
Solid Freeform Fabrication ◽  
Surface Topology ◽  
Distributed Parameter ◽  
Surface Geometry ◽  
Mass Source ◽  
Freeform Fabrication ◽  
Geometry Model ◽  
Material Deposition ◽  
Solid Objects ◽  
3D Solid

Recent solid freeform fabrication methods generate 3D solid objects by material deposition in successive layers made of adjacent beads. Besides numerical simulation, this article introduces an analytical model of such material addition, using superposition of unit deposition distributions, composed of elementary spherical primitives consistent with the mass transfer physics. This real-time surface geometry model, with its parameters identified by in-process profile measurements, is used for Smith-prediction of the material shape in the unobservable deposition region. The model offers the basis for a distributed-parameter geometry control scheme to obtain a desired surface topology, by modulating the feed and motion of a moving mass source. The model was experimentally tested on a fused wire deposition welding station, using optical sensing by a scanning laser stripe. Its applications to other rapid prototyping methods are discussed. [S0022-0434(00)02301-7]

Simultaneous Determination of Steady Temperatures and Heat Fluxes on Surfaces of Three Dimensional Objects Using FEM

2001 ◽  
Author(s):  
Brian H. Dennis ◽  
George S. Dulikravich
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Heat Conduction ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Multiply Connected ◽  
Three Dimensional Objects ◽  
Solid Objects ◽  
System Solution

Abstract A finite element method (FEM) formulation is presented for the prediction of unknown steady boundary conditions in heat conduction on multiply connected three-dimensional solid objects. The present FEM formulation is capable of determining temperatures and heat fluxes on the boundaries where such quantities are unknown or inaccessible, provided such quantities are sufficiently over-specified on other boundaries. Details of the discretization, linear system solution techniques, regularization, and sample results for 3-D problems are presented.

CAD Platform Independent Software for Automatic Grading of Technical Drawings

2017 ◽  
Author(s):  
Sanchit Ingale ◽  
Anirudh Srinivasan ◽  
Diana Bairaktarova
Keyword(s):  
Engineering Students ◽  
Spatial Reasoning ◽  
Learning Experience ◽  
Spatial Visualization ◽  
First Year ◽  
Spatial Skills ◽  
First Year Students ◽  
Pedagogical Tool ◽  
Students Success ◽  
Mechanical Objects

Spatial visualization is the ability of an individual to imagine an object mentally and understand its spatial orientation. There have been multiple works proving that spatial visualization skills can be improved with an appropriate training. Such training warrant a critical place in the undergraduate engineering curricula in many engineering schools as spatial skills are considered vital for students’ success in the technical and design fields [1–4]. Enhanced spatial skills help not only professionals in the engineering field but also everyone in the 21st century environment. Drawing sectional views requires mental manipulation and visual thinking. To enhance students spatial reasoning, one of the authors of this study, conducted a class in spatial visualization. The course-learning goal aimed at improving first-year engineering students’ spatial reasoning through instruction on freehand drawings of sectional view. During the semester, two teaching assistants had to grade more than 500 assignments that consisted of sectional views of mechanical objects. This was a tedious and a time consuming task. Motivated by this experience, this paper proposes a software aiming at automating grading of students’ sectional view drawings. The proposed software will also give live feedback to students while they are working on the drawings. This interactive tool aims to 1) improve the learning experience of first year students, with limited CAD knowledge, and 2) introduce a pedagogical tool that can enhance spatial visualization training.

Research and Realization of a New Algorithm for Stereo Matching Based on Binocular Vision

2013 ◽  
Vol 670 ◽  
pp. 202-207 ◽  
Author(s):  
Jun Ting Cheng ◽  
C. Zhao ◽  
W.L. Zhao ◽  
W.H. Wu
Keyword(s):  
Binocular Vision ◽  
Stereo Matching ◽  
Three Dimensional ◽  
Cnc Machining ◽  
Matching Algorithm ◽  
Evaluation Test ◽  
Three Dimensional Measurement ◽  
Binocular Stereo ◽  
Measuring Machine ◽  
3D Solid

In the development of a three-dimensional measurement system, binocular stereo matching is the most important and difficult. In the basis of introducing selective principles of matching algorithm, a new stereo matching algorithm for binocular vision is put forward that is named noncoded difference measuring distance. The algorithm effectively grapples with the problem of searching for the coincidence relation of raster and can efficiently and accurately obtain three-dimensional world coordinates of the entities. Experiment results show that this 3D measuring machine can effectively measure the 3D solid profile of free surface. During the evaluation test for accuracy, scan a standard plane. Fit all 3D points in one plane, and then the flatness value of this plane is obtained. The flatness value of the standard plane has been ultimately measured as: ± 0.0462mm, this measuring accuracy can completely satisfy the requirements of rapid prototyping or CNC machining, it as well as achieves the stated accuracy (± 0.05mm).

Preliminary Evaluation of an Electromagnetic Three-Dimensional Digitizer in Facial Anthropometry

1998 ◽  
Vol 35 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Virgilio F. Ferrario ◽  
Chiarella Sforza ◽  
Carlo E. Poggio ◽  
Massimiliano Cova ◽  
Gianluca Tartaglia
Keyword(s):  
Three Dimensional ◽  
Preliminary Evaluation ◽  
Men And Women ◽  
Facial Landmarks ◽  
Coefficients Of Variation ◽  
The Face ◽  
Human Adults ◽  
Facial Anthropometry ◽  
Sufficient Precision

Objective In this investigation, the precision of a commercial three-dimensional digitizer in the detection of facial landmarks in human adults was assessed. Methods Fifty landmarks were identified and marked on the faces of five men, on five women, and on a stone cast of the face of one man. For each subject, the three-dimensional coordinates of the landmarks were obtained twice using an electromagnetic three-dimensional digitizer, and the duplicate digitizations were superimposed using common orientations and centers of gravity. Metric differences between homologous landmarks were assessed, and Dahlberg's error was computed. Results For both men and women, the error was 1.05% of the nasion-mid-tragion distance, while for the cast, it was 0.9%. When the duplicate digitizations were used to mathematically reconstruct the faces, and several distances, angles, volumes, and surfaces were computed, more than 80% of the measurements had coefficients of variation lower than 1%. Conclusions The digitizer can assess the coordinates of facial landmarks with sufficient precision, and reliable measurements can be obtained.

scholarly journals Three-Dimensional Graph Matching to Identify Secondary Structure Correspondence of Medium-Resolution Cryo-EM Density Maps

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1773
Author(s):  
Bahareh Behkamal ◽  
Mahmoud Naghibzadeh ◽  
Mohammad Reza Saberi ◽  
Zeinab Amiri Tehranizadeh ◽  
Andrea Pagnani ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Graph Matching ◽  
Protein Complexes ◽  
Three Dimensional ◽  
Protein Structure Determination ◽  
Secondary Structures ◽  
Computational Method ◽  
Target Sequence ◽  
Matching Problem ◽  
Medium Resolution

Cryo-electron microscopy (cryo-EM) is a structural technique that has played a significant role in protein structure determination in recent years. Compared to the traditional methods of X-ray crystallography and NMR spectroscopy, cryo-EM is capable of producing images of much larger protein complexes. However, cryo-EM reconstructions are limited to medium-resolution (~4–10 Å) for some cases. At this resolution range, a cryo-EM density map can hardly be used to directly determine the structure of proteins at atomic level resolutions, or even at their amino acid residue backbones. At such a resolution, only the position and orientation of secondary structure elements (SSEs) such as α-helices and β-sheets are observable. Consequently, finding the mapping of the secondary structures of the modeled structure (SSEs-A) to the cryo-EM map (SSEs-C) is one of the primary concerns in cryo-EM modeling. To address this issue, this study proposes a novel automatic computational method to identify SSEs correspondence in three-dimensional (3D) space. Initially, through a modeling of the target sequence with the aid of extracting highly reliable features from a generated 3D model and map, the SSEs matching problem is formulated as a 3D vector matching problem. Afterward, the 3D vector matching problem is transformed into a 3D graph matching problem. Finally, a similarity-based voting algorithm combined with the principle of least conflict (PLC) concept is developed to obtain the SSEs correspondence. To evaluate the accuracy of the method, a testing set of 25 experimental and simulated maps with a maximum of 65 SSEs is selected. Comparative studies are also conducted to demonstrate the superiority of the proposed method over some state-of-the-art techniques. The results demonstrate that the method is efficient, robust, and works well in the presence of errors in the predicted secondary structures of the cryo-EM images.

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