This article investigated the impact of immersive virtual reality (VR) content, using 360-degree videos, in undergraduate education. To improve the delivery and reality of 360-degree VR content, we filmed the video in the third person so that the viewers could feel like they were in the environment where the lecture was conducted. To verify the educational effects, 33 university students participated in our experiment. We conducted pretest learning, using 360-degree videos, and posttest learning via conventional 2-D videos for statistical analysis. A paired t -test was used to compare the means of the pretest and the posttest. In addition, learning via 360-degree videos was assessed for its effectiveness through questionnaires consisting of five measurement elements—engagement, immersion, motivation, cognitive benefits, and perceived learning effectiveness—and comparing them to the existing 2-D video method, based on e-learning. From the results, we confirmed that the teaching material delivered through 360-degree VR content allows students to be more focused, immersed, and interested than 2-D learning modes. Furthermore, the high scores of cognitive and perceived learning elements imply that VR-based 360-degree educational content can encourage more active participation than traditional lectures and can improve the ability to analyze and organize study lessons.

Conventional digital learning with 2D videos or simulations on monitors and tablets has limitations in engineering education when covering complex concepts or complicated 3D structures. In response, virtual reality (VR) has been introduced as an immersive method that can enhance learning effectiveness. This study analyzed the impact of VR on overall learning outcomes and understanding of 3D structures in engineering education, comparing it with traditional digital learning approaches. We conducted a study with 40 participants who learned about LCD-related topics using two methods: VR-based learning and 2D video-based learning (2DLM). To evaluate their performance, we carried out a performance-based assessment consisting of a quiz and 3D reconstruction tasks, as well as a perception-based assessment using a questionnaire. As for the results, the VR-based learning showed a 12% improvement in post-test quiz scores and a 13% improvement in 3D reconstruction test scores compared to the 2DLM. Additionally, the questionnaire results confirmed that VR learning increased engagement by 11.9%, immersion by 18.6%, motivation by 10.3%, cognitive benefits by 9.3%, and perceived learning effectiveness by 8.7%. While VR showed better learning outcomes, these findings should be interpreted considering the small sample size, the specific learning topics addressed, and the partial integration of media and educational methods. Nevertheless, our results indicate that VR is more effective than conventional learning resources in supporting general memorization, understanding, and the specific comprehension of 3D structures.

A liquid-crystal (LC)-based floating electrode-free (FE-free) coplanar waveguide (CPW) phase shifter with an additional LC layer is demonstrated for the first time. An LC layer is overlain on the electrodes of the original model; this change increases the amount of electric flux that the proposed structure can confine in the tunable region, and thereby greatly increases the figure-of-merit (FoM) while maintaining the benefits of the simple coplanar structure. We simulated the variations in the phase shifter’s FoM, characteristic impedance, and driving voltage while sweeping the additional LC layer thickness up to 300 μm with each electrode condition at 28 GHz. In the case of electrode thickness variation, the FoM increased as electrode thickness increased, regardless of the presence of the additional LC layer. However, in the case of the signal electrode width variation, we obtained an opposite FoM tendency depending on the presence of the additional LC layer. This work shows the possibility of an efficient LC-based FE-free CPW phase shifter design for a given LC layer and electrode conditions.

We propose an isolated high-voltage-gain quasi-resonant dc–dc converter with a bifunctional circuit for the renewable-energy applications. The proposed converter adopts an interleaved connection in the primary side, reducing input-current ripple, and includes the bifunctional circuit operating as the switched-capacitor cells and two active-clamped circuits simultaneously. The converter realizes high-voltage-conversion ratio without using extreme duty ratio, and the voltage spike due to the leakage inductance of the isolation transformer is clamped. In addition, an output voltage doubler in the secondary side comprises a series resonant circuit and then obtains zero-current switching turn- off of rectifying diodes; the diode reverse-recovery problems are also alleviated. A 320 W laboratory prototype that operates at input of 26–34 V and output of 400 V is fabricated to verify the effectiveness of the proposed converter.

Using a single substrate, we demonstrate a simple two-dimensional (2-D) phase grating cell with an octothorp electrode. Owing to the large spatial phase difference in any direction, the proposed grating cell has a high haze value in the opaque state (76.7%); Moreover, it has the advantages of a one-dimensional (1-D) phase grating cell, such as high fabricability, fast response time, and low operating voltage. Furthermore, the proposed grating cell has a faster response time than the 2-D grating cell (comparable to a 1-D grating cell). All the electro-optic parameters have been calculated using a commercial modeling tool. Consequently, we expect our proposed grating cell to find applications in virtual reality (VR)/augmented reality (AR) systems or window displays with fast response times.