• International Journal of Internet, Broadcasting and Communication
• /
• v.16 no.3
• /
• pp.77-84
• /
• 2024

Aberration is still a problem for making augmented reality displays. The existing methods to solve this problem are either slow and inefficient, consume too much battery, or are too complex for straightforward implementation. There are still some problems with image quality, and users may suffer from eye strain and headaches because the images provided to each eye lack accuracy, causing the brain to receive mismatched cues between the vergence and accommodation of the eyes. In this paper, we implemented a computer simulation of an optical aberration using Zernike polynomials which are defocus, trefoil, coma, and spherical. The research showed that these optical aberrations impact the Point Spread Function (PSF) and Modulation Transfer Function (MTF). We employed the phase conjugate technique to mitigate aberrations. The findings revealed that the most significant impact on the PSF and MTF comes from the influence of spherical aberration and coma aberration.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.7
• /
• pp.1907-1928
• /
• 2024

In recent years, multi-focus image fusion has emerged as a prominent area of research, with transformers gaining recognition in the field of image processing. Current approaches encounter challenges such as boundary artifacts, loss of detailed information, and inaccurate localization of focused regions, leading to suboptimal fusion outcomes necessitating subsequent post-processing interventions. To address these issues, this paper introduces a novel multi-focus image fusion technique leveraging the Swin Transformer architecture. This method integrates a frequency layer utilizing Wavelet Transform, enhancing performance in comparison to conventional Swin Transformer configurations. Additionally, to mitigate the deficiency of local detail information within the attention mechanism, Convolutional Neural Networks (CNN) are incorporated to enhance region recognition accuracy. Comparative evaluations of various fusion methods across three datasets were conducted in the paper. The experimental findings demonstrate that the proposed model outperformed existing techniques, yielding superior quality in the resultant fused images.

• Fisheries and Aquatic Sciences
• /
• v.27 no.9
• /
• pp.552-564
• /
• 2024

This paper used the UK Agency for International Development sustainable livelihood framework to measure small-scale in-land fishing household's livelihood by sustainable livelihood capital index in the vulnerable context of aquatic natural resource depletion in the wetland forest of Ca Mau province, Vietnam. Findings indicated that fishing households' livelihood capital is unsustainable and inadequate. The result took note of the beneficial physical capital while underlining the human, natural, financial, and social capital's limitations in achieving livelihood sustainability. The limitations were found to be a low score of composite index of sustainable livelihood capital (less than an average score of 0.5) whereas the outstanding score of physical capital was found. Providing training in the adoption of new livelihood models, learning livelihood diversification, access to formal credit, and appropriate coverage of social safety-net programs might help mitigate the unsustainable livelihood of inland fishing households.

• Nuclear Engineering and Technology
• /
• v.56 no.5
• /
• pp.1627-1637
• /
• 2024

This research paper proposes a novel methodology for predicting the optimal location of friction supports to effectively mitigate vibrational energy in piping systems. The incorporation of friction forces in the dynamic characteristics of the system introduces inherent nonlinearity, making its analysis challenging. Typically, numerical solutions in the time domain are employed to circumvent the complexities associated with finding analytic solutions for nonlinear systems. However, time domain analysis (TDA) can be computationally intensive and demand significant computational resources due to the intricate calculations stemming from nonlinearity. To address this computational burden, this study presents an efficient approach based on linear analysis to predict the ideal position for installing friction supports as a replacement for fixed supports. Furthermore, we investigate the relationship between the installation positions of friction supports and their effectiveness in absorbing vibrations using the harmonic balanced method (HBM). Both methodologies are validated by comparing the obtained results with those obtained through time domain analysis (TDA) using the finite element method (FEM).

• Journal of Engineering Education Research
• /
• v.27 no.4
• /
• pp.21-27
• /
• 2024

This study introduces a series of processes aimed at understanding the noise characteristics generated by jet engines and devising measures to mitigate them through interdisciplinary capstone design projects. During the project execution, educational methods were applied to foster 4Cs (creativity, communication, collaboration, critical thinking) competencies. Project objectives were set through team discussions, and individual team members were assigned primary roles to act as subgroup leaders. As a result, the project was executed as follows: combustion tests were conducted using an SR-30 turbojet engine to generate noise, and the locations and characteristics of the noise sources were identified using beamforming techniques and frequency analysis applied to a 30-microphone array. Additionally, chevron nozzles were designed and fabricated to confirm their noise reduction performance.

• Journal of the Korean Society of Visualization
• /
• v.22 no.2
• /
• pp.90-95
• /
• 2024

This study examined changes in airway airflow characteristics before and after extensive surgery for tongue cancer, which includes neck dissection and reconstruction. Pre- and post-operative CBCT scans were used to model 3D upper airways. Computational fluid dynamics (CFD) simulations analyzed airflow and pressure variations. Results showed a significant reduction in airway volume post-surgery, especially in the posterior tongue and epiglottis areas, leading to increased airflow velocity and complex vortex formations. Pressure drop analysis revealed that post-surgery, higher negative pressure is required for inhalation, indicating increased breathing effort. This suggests that the surgical removal of cancerous tissues and lymph nodes, along with reconstruction, alters airway geometry significantly, potentially impacting respiratory function. The findings highlight the clinical importance of assessing airway changes in tongue cancer surgery to anticipate and mitigate postoperative respiratory complications.

• Communications for Statistical Applications and Methods
• /
• v.31 no.5
• /
• pp.557-569
• /
• 2024

Based on the investigation of logistic regression models utilizing sparse triangulation within a compact domain in ℝ², this study addresses the limited research extending the triogram model to logistic regression. A primary challenge arises from the potential instability induced by a large number of vertices, hindering the effective modeling of complex relationships. To mitigate this challenge, we propose introducing sparsity to boundary vertices of the triangulation based on the Ramer-Douglas-Peucker algorithm and employing the K-means algorithm for adaptive vertex initialization. A second order coordinate-wise descent algorithm is adopted to implement the proposed method. Validation of the proposed algorithm's stability and performance assessment are conducted using synthetic and handwritten digit data (LeCun et al., 1989). Results demonstrate the advantages of our method over existing methodologies, particularly when dealing with non-rectangular data domains.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.5
• /
• pp.519-526
• /
• 2024

This review examines the use of halide perovskite materials in electronic devices, highlighting their exceptional optoelectronic properties and the challenges associated with them. Despite their potential for high-performance devices, practical applications are limited by sensitivity to environmental factors such as moisture and oxygen, etc. We discuss advances in enhancing stability and operational reliability, featuring innovative synthesis methods and device engineering strategies that help mitigate degradation. Furthermore, we explore the integration of perovskites in applications such as field-effect transistors and LEDs, emphasizing their transformative potential. This review also outlines future research directions, stressing the need for ongoing improvements in material stability and device integration to fully realize the commercial potential of perovskites.

• International journal of advanced smart convergence
• /
• v.13 no.3
• /
• pp.183-190
• /
• 2024

This study investigates the conditions under which the compensation effect occurs in advertising, focusing on the influence of warmth messages on consumer perceptions and responses. By comparing single-ad and comparative ad exposure contexts, the research reveals how warmth messages affect perceived brand competence and the intention to like ads. High warmth messages, when viewed in a comparative ad setting, lead to lower perceived brand competence compared to a single-ad setting, emphasizing the need for strategic message placement in competitive environments. The study further explores how consumers' construal levels-whether considering near-future or distant-future purchase decisions-moderate these effects. The negative impact of high warmth messages on perceived competence is amplified in a comparative context at low construal levels, while high construal levels mitigate this negative impact. These results provide both theoretical and practical insights, highlighting the importance of ad context and construal level in advertising strategies.

• International journal of advanced smart convergence
• /
• v.13 no.3
• /
• pp.109-116
• /
• 2024

With the advent of serverless computing, cloud customers no longer needed to maintain and manage server environments directly. Instead, cloud service providers took on that role, managing and maintaining the server environment according to customer requests, a concept known as Function as a Service (FaaS). This service demonstrated improvements in operational costs and resource utilization over traditional cloud computing, offering various advantages such as enhanced scalability. However, a delay occurred in processing and returning results to user requests, a phenomenon referred to as the cold start problem. This paper proposed the Time Warming Allocation Engine (TWAE) to improve resource management and mitigate the cold start problem in Function as a Service. The proposed engine comprised a collection module, a learning module, a classification module, and an allocation module. Additionally, it utilized a list called Pre-Warming. Through this approach, it suggested directions for improving cold start issues and resource utilization according to different time periods.