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24 pages, 4285 KiB

Open AccessArticle

A Virtual Experiment for Learning the Principle of Daniell Cell Based on Augmented Reality

by Wernhuar Tarng, Yu-Jun Lin and Kuo-Liang Ou

Appl. Sci. 2021, 11(2), 762; https://0-doi-org.brum.beds.ac.uk/10.3390/app11020762 - 14 Jan 2021

Cited by 18 | Viewed by 4621

Chemistry is a science emphasizing both theory and experimentation. After learning the theoretical knowledge, experimental operation can help students understand chemical concepts and transform them into practical knowledge. Considering the safety issue and the lack of teaching time and experimental equipment, some teachers [...] Read more.

Chemistry is a science emphasizing both theory and experimentation. After learning the theoretical knowledge, experimental operation can help students understand chemical concepts and transform them into practical knowledge. Considering the safety issue and the lack of teaching time and experimental equipment, some teachers often choose to demonstrate an experiment instead of letting students conduct it by themselves. This may affect their learning motivation as well as the construction of chemical concepts and hands-on skills. This study combined the augmented reality (AR) technology with the operating principle of the Daniell cell to develop a virtual experiment for the application in high school chemistry courses. Students can conduct the virtual experiment using mobile devices by selecting the required equipment and materials from a deck of cards to set up the experimental environment. In the virtual experiment, students can use the galvanometer to measure the current after mounting the salt bridge on the beakers containing zinc sulfate and copper sulfate solutions. They can also see the change of molecular structures and movement of electrons and ions during the redox reactions to understand the important concepts and knowledge. An empirical research has been performed, and the analytical results show that both the virtual experiment and the real experiment could improve students’ learning achievement, but the former was more effective for the low-achievement students because they could explore autonomously to enhance cognition by observing the submicroscopic view of the redox reactions. The post-test results show that the average score of the low-achievement students in the experimental group (41.60) was significantly higher than that of the control group (27.67). Questionnaire results reveal that most students were satisfied with the learning contents, user interface, learning motivation, system reality, and practicality of the virtual experiment, and the average satisfaction score was 3.98 out of 5. The application of virtual experiments is not limited by time or space. Students only need to download the application (APP) software and print out the AR cards to practice at home, so it is suitable for large-scale promotion in rural areas. Full article

(This article belongs to the Special Issue X Reality Technologies, Systems and Applications)

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23 pages, 10821 KiB

Open AccessFeature PaperArticle

Representing Virtual Transparent Objects on Optical See-Through Head-Mounted Displays Based on Human Vision

by Yuto Kimura, Asako Kimura and Fumihisa Shibata

Appl. Sci. 2021, 11(2), 495; https://0-doi-org.brum.beds.ac.uk/10.3390/app11020495 - 06 Jan 2021

Cited by 1 | Viewed by 2056

Abstract

In this study, we propose two methods for representing virtual transparent objects convincingly on an optical see-through head-mounted display without the use of an attenuation function or shielding environmental light. The first method represents the shadows and caustics of virtual transparent objects as [...] Read more.

In this study, we propose two methods for representing virtual transparent objects convincingly on an optical see-through head-mounted display without the use of an attenuation function or shielding environmental light. The first method represents the shadows and caustics of virtual transparent objects as illusionary images. Using this illusion-based approach, shadows can be represented without blocking the luminance produced by the real environment, and caustics are represented by adding the luminance of the environment to the produced shadow. In the second method, the visual effects that occur in each individual image of a transparent object are represented as surface, refraction, and reflection images by considering human binocular movement. The visual effects produced by this method reflect the disparities among the vergence and defocus of accommodation associated with the respective images. When reproducing the disparity, each parallax image is calculated in real time using a polygon-based method, whereas when reproducing the defocus, image processing is applied to blur each image and consider the user’s gaze image. To validate these approaches, we conducted experiments to evaluate the realism of the virtual transparent objects produced by each method. The results revealed that both methods produced virtual transparent objects with improved realism. Full article

(This article belongs to the Special Issue X Reality Technologies, Systems and Applications)

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15 pages, 11231 KiB

Open AccessFeature PaperArticle

Pose Estimation of Primitive-Shaped Objects from a Depth Image Using Superquadric Representation

by Ryo Hachiuma and Hideo Saito

Appl. Sci. 2020, 10(16), 5442; https://0-doi-org.brum.beds.ac.uk/10.3390/app10165442 - 06 Aug 2020

Cited by 5 | Viewed by 3083

Abstract

This paper presents a method for estimating the six Degrees of Freedom (6DoF) pose of texture-less primitive-shaped objects from depth images. As the conventional methods for object pose estimation require rich texture or geometric features to the target objects, these methods are not [...] Read more.

This paper presents a method for estimating the six Degrees of Freedom (6DoF) pose of texture-less primitive-shaped objects from depth images. As the conventional methods for object pose estimation require rich texture or geometric features to the target objects, these methods are not suitable for texture-less and geometrically simple shaped objects. In order to estimate the pose of the primitive-shaped object, the parameters that represent primitive shapes are estimated. However, these methods explicitly limit the number of types of primitive shapes that can be estimated. We employ superquadrics as a primitive shape representation that can represent various types of primitive shapes with only a few parameters. In order to estimate the superquadric parameters of primitive-shaped objects, the point cloud of the object must be segmented from a depth image. It is known that the parameter estimation is sensitive to outliers, which are caused by the miss-segmentation of the depth image. Therefore, we propose a novel estimation method for superquadric parameters that are robust to outliers. In the experiment, we constructed a dataset in which the person grasps and moves the primitive-shaped objects. The experimental results show that our estimation method outperformed three conventional methods and the baseline method. Full article

(This article belongs to the Special Issue X Reality Technologies, Systems and Applications)

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