scholarly journals An Object Model and Interaction Method for a Simulated Experience of Pottery on a Potter’s Wheel

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3091
Author(s):  
Takafumi Matsumaru ◽  
Ami Morikawa

This paper introduces an object model and an interaction method for a simulated experience of pottery on a potter’s wheel. Firstly, we propose a layered cylinder model for a 3D object of the pottery on a potter’s wheel. Secondly, we set three kinds of deformation functions to form the object model from an initial state to a bowl shape: shaping the external surface, forming the inner shape (deepening the opening and widening the opening), and reducing the total height. Next, as for the interaction method between a user and the model, we prepare a simple but similar method for hand-finger operations on pottery on a potter’s wheel, in which the index finger movement takes care of the external surface and the total height, and the thumb movement makes the inner shape. Those are implemented in the three-dimensional aerial image interface (3DAII) developed in our laboratory to build a simulated experience system. We confirm the operation of the proposed object model (layered cylinder model) and the functions of the prepared interaction method (a simple but similar method to actual hand-finger operations) through a preliminary evaluation of participants. The participants were asked to make three kinds of bowl shapes (cylindrical, dome-shaped, and flat-type) and then they answered the survey (maneuverability, visibility, and satisfaction). All participants could make something like three kinds of bowl shapes in less than 30 min from their first touch.

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1042
Author(s):  
Rafał Krupiński

The paper presents the opportunities to apply computer graphics in an object floodlighting design process and in an analysis of object illumination. The course of object floodlighting design has been defined based on a virtual three-dimensional geometric model. The problems related to carrying out the analysis of lighting, calculating the average illuminance, luminance levels and determining the illuminated object surface area are also described. These parameters are directly tied with the calculations of the Floodlighting Utilisation Factor, and therefore, with the energy efficiency of the design as well as the aspects of light pollution of the natural environment. The paper shows how high an impact of the geometric model of the object has on the accuracy of photometric calculations. Very often the model contains the components that should not be taken into account in the photometric calculations. The research on what influence the purity of the geometric mesh of the illuminated object has on the obtained results is presented. It shows that the errors can be significant, but it is possible to optimise the 3D object model appropriately in order to receive the precise results. For the example object presented in this paper, removing the planes that do not constitute its external surface has caused a two-fold increase in the average illuminance and average luminance. This is dangerous because a designer who wants to achieve a specific average luminance level in their design without optimizing the model will obtain the luminance values that will actually be much higher.


Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).


Author(s):  
Chang Liu ◽  
Ying Zhong ◽  
Sertac Ozercan ◽  
Qing Zhu

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.


Author(s):  
Virgilio F. Ferrario ◽  
Chiarella Sforza ◽  
Carlo E. Poggio ◽  
Massimiliano Cova ◽  
Gianluca Tartaglia

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.


2021 ◽  
Vol 7 ◽  
Author(s):  
Vasiliki Terzi ◽  
Asimina Athanatopoulou

The present study aims to investigate the effects of the seismic vertical component on the pathology of Xana monument which is a typical caravanserai, constructed circa 1375–1385 and is located in the archeological site of the municipality of Trainapoulis, Greece. The monument’s plan is rectangular and the three-leaf masonry circumferential walls support a hemicylindrical dome constructed by bricks and mortar. The structure consisted of two consecutive parts: one for the travelers and one for the animals. Nowadays, the triangular roof, that covered the structure, and the first part of the monument do not exist. Xana suffers tensile cracks along the interior surface of the dome, a vertical fracture located on the northern wall and vertical tensile cracks located at the openings. A three-dimensional finite element model of the initial state of Xana is constructed. Non-linear material behavior is taken into account as well as soil-structure interaction effects. An adequate number of near-field earthquake events has been used, taking into account that they are related to significant vertical components. The structural seismic analysis is conducted for two cases. The first case refers to the action of the two horizontal-component of ground motions while the second one takes into account the three translational seismic components. The pathology estimation reveals important information concerning the structural effects due to vertical accelerations.


Author(s):  
Marina L. Mozgaleva ◽  
Pavel A. Akimov ◽  
Taymuraz B. Kaytukov

he distinctive paper is devoted to so-called multigrid (particularly two-grid) method of structural analysis based on discrete Haar basis (one-dimensional, two-dimensional and three-dimensional problems are under consideration). Approximations of the mesh functions in discrete Haar bases of zero and first levels are described (the mesh function is represented as the sum in which one term is its approximation of the first level, and the second term is so-called complement (up to the initial state) on the grid of the first level). Special projectors are constructed for the spaces of vector functions of the original grid to the space of their approximation on the first-level grid and its complement (the refinement component) to the initial state. Basic scheme of the two-grid method is presented. This method allows solution of boundary problems of structural mechanics with the use of matrix operators of significantly smaller dimension. It should be noted that discrete analogue of the initial operator equation is a system of linear algebraic equations which is constructed with the use of finite element method or finite difference method. Block Gauss method can be used for direct solution.


Author(s):  
Ilmawan Mustaqim

AbstrakAugmented Reality (AR) dapat didefinisikan sebagai sebuah teknologi yang mampu menggabungkan benda maya dua dimensi atau tiga dimensi ke dalam sebuah lingkungan yang nyata kemudian memunculkannya atau memproyeksikannya secara real time. AR dapat digunakan untuk membantu memvisualisasikan konsep abstrak untuk pemahaman dan struktur suatu model objek. Beberapa aplikasi AR dirancang untuk memberikan informasi yang lebih detail pada pengguna dari objek nyata. Media merupakan sebuah alat atau objek yang berfungsi sebagai penghubung antara penerima dan pengirim pesan.Media pembelajaran merupakan suatu alat perantara antara pendidik dengan peserta didik dalam pembelajaran yang mampu menghubungkan, memberi informasi dan menyalurkan pesan sehingga tercipta proses pembelajaran efektif dan efisien. Media pembelajaran mengakibatkan terjadinya sebuah komunikasi antara pendidik dan peserta didik dalam proses pembelajaran. Apabila dalam proses pembelajaran tidak menggunakan media maka tidak akan terjadi proses pembelajaran.Pemanfaatan media pendidikan menggunakan Augmented Reality dapat merangsang pola pikir peserta didik dalam berpikiran kritis terhadap sesuatu masalah dan kejadian yang ada pada keseharian, karena sifat dari media pendidikan adalah membantu peserta didik dalam proses pembelajaran dengan ada atau tidak adanya pendidik dalam proses pendidikan, sehingga pemanfaatan media pendidikan dengan augmented reality dapat secara langsung memberikan pembelajaran dimanapun dan kapanpun peserta didik ingin melaksanakan proses pembelajaran. Media Pembelajaran AR dapat memvisualisasikan konsep abstrak untuk pemahaman dan struktur suatu model objek memungkinkan AR sebagai media yang lebih efektif sesuai dengan tujuan dari media pembelajaran. Kata kunci:  augmented reality, media pembelajaran AbstractAugmented Reality (AR) can be defined as a technology that can combine virtual objects two-dimensional or three-dimensional into a real environment and then bring it or project it in real time. AR can be used to help visualize abstract concepts for the understanding and the structure of an object model. Some AR application designed to provide more detailed information on the user of the real object. Media is a tool or object that serves as a liaison between the recipient and the sender of the message.Learning Media is an intermediary tool between educators with learners in the learning that is able to connect, inform and distribute the messages so as to create an effective and efficient learning process. Instructional media resulting in a communication between educators and learners in the learning process. If the learning process does not use the media then there will be a learning process.Implementation media education using Augmented Reality can be stimulate the mindset of students in critical thinking about something issues and events that exist in everyday life, because of the nature of the medium of education is to help learners in the learning process with the presence or absence of teachers in the educational process, so that the use of the media augmented education with reality can directly provide learning wherever and whenever the learner wants to implement the learning process. Learning Media AR can visualize abstract concepts for the understandingand the structure of an object model enables the AR as a more effective media in accordance with the purpose of learning media. Keywords : augmented raeality, utilzation of instructional media


Author(s):  
A. Finn ◽  
K. Rogers ◽  
J. Meade ◽  
J. Skinner ◽  
A. Zargarian

<p><strong>Abstract.</strong> An acoustic signature generated by an unmanned aerial vehicle is used in conjunction with tomography to remotely sense temperature and wind profiles within a volume of atmosphere up to an altitude of 120&amp;thinsp;m and over an area of 300&amp;thinsp;m&amp;thinsp;&amp;times;&amp;thinsp;300&amp;thinsp;m. Sound fields recorded onboard the aircraft and by an array of microphones on the ground are compared and converted to sound speed estimates for the ray paths intersecting the intervening medium. Tomographic inversion is then used to transform these sound speed values into three-dimensional profiles of virtual temperature and wind velocity, which enables the atmosphere to be visualised and monitored over time. The wind and temperature estimates obtained using this method are compared to independent measurements taken by a co-located mid-range ZephIR LIDAR and sensors onboard the aircraft. These comparisons show correspondences to better than 0.5&amp;thinsp;&amp;deg;C and 0.3&amp;thinsp;m/s for temperature and wind velocity, respectively.</p>


2012 ◽  
Vol 190 ◽  
pp. 39-42
Author(s):  
M. Medvedeva ◽  
Pavel V. Prudnikov

The dynamic critical behavior of the three-dimensional Heisenberg model with longrangecorrelated disorder was studied by using short-time Monte Carlo simulations at criticality.The static and dynamic critical exponents are determined. The simulation was performed fromordered initial state. The obtained values of the exponents are in a good agreement with resultsof the field-theoretic description of the critical behavior of this model in the two-loopapproximation.


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