• Journal of Broadcast Engineering
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• v.28 no.1
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• pp.3-20
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• 2023

A computer-generated hologram (CGH) is a digitally calculated and recorded hologram in which the amplitude and phase information of an image is transmitted in free space. The CGH is in the form of a complex hologram, but it is converted into a phase-only hologram to display through a phase-only spatial light modulator (SLM). In this paper, in the process of including the amplitude information of an object in the phase information, when a technique that includes subsampling such as DPAC is used, we showed experimentally that the bandwidth of the phase-only hologram increases, and as a result, aliasing that was not present in the complex hologram can occur. In addition, it was experimentally shown that it is possible to generate a high-quality phase-only hologram by restricting the spatial frequency range even at a distance where the numerical reconstruction performance is degraded by aliasing.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.369-375
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• 2004

Gas turbine engine simulation in terms of transient, steady state performance and operational characteristics is complex work at the various engineering functions of aero engine manufacturers. Especially, efficiency of control system design and development in terms of cost, development period and technical relevance implies controlling diverse simulation and identification activities. The previous engine simulation has been accomplished within a limited analysis area such as fan, compressor, combustor, turbine, controller, etc. and this has resulted in improper engine performance and control characteristics because of limited interaction between analysis areas. In this paper, we propose a new simulation methodology for gas turbine engine performance analysis as well as its digital controller to solve difficulties as mentioned above. The novel method has particularities of (ⅰ) resulting in the integrated control simulation using almost every component/module analysis, (ⅱ) providing automated math model generation process of engine itself, various engine subsystems and control compensators/regulators, (ⅲ) presenting total sophisticated output results and easy understandable graphic display for a final user. We call this simulation system GT3GS (Gas Turbine 3D Graphic Simulator). GT3GS was built on both software and hardware technology for total simulation capable of high calculation flexibility as well as interface with real engine controller. All components in the simulator were implemented using COTS (Commercial Off the Shelf) modules. In addition, described here includes GT3GS main features and future works for better gas turbine engine simulation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.5
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• pp.423-432
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• 2023

With the increasing demand for mobile devices featuring multi-touch operation, extensive research is being conducted on touch screen panel (TSP) Readout ICs (ROICs) that should possess low power consumption, compact chip size, and immunity to external noise. Therefore, this paper discusses capacitive touch sensors and their readout circuits, and it introduces research trends in various circuit designs that are robust against external noise sources. The recent state-of-the-art TSP ROICs have primarily focused on minimizing the impact of parasitic capacitance (Cp) caused by thin panel thickness. The large Cp can be effectively compensated using an area-efficient current compensator and Current Conveyor (CC), while a display noise reduction scheme utilizing a noise-antenna (NA) electrode significantly improves the signal-to-noise ratio (SNR). Based on these achievements, it is expected that future TSP ROICs will be capable of stable operation with thinner and flexible Touch Screen Panels (TSPs).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.4
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• pp.93-98
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• 2023

Recently, as the size of display devices tends to increase and taking pictures with smart phones has become commonplace, the need for taking high-resolution pictures with smart phones is increasing. However, when the lens size of a camera is limited, such as in a smartphone, there is a physical limit to increasing the resolution of a photo. This paper is about a technique for increasing the resolution of a picture even when using a small-sized lens like a smartphone camera. It is to take multiple pictures while moving the smartphone, and to increase the resolution by combining these pictures into one picture. First of all, two pictures were taken while moving the smartphone horizontally for the 2D picture. Processes such as camera matrix estimation, and homograph inverse transformation were performed using OpenCV, and the resolution was improved by synthesizing one picture. It was confirmed that the resolution was improved in parts such as oblique lines or arcs on several test pictures.

• Asia Marketing Journal
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• v.18 no.2
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• pp.63-93
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• 2016

As one of the most popular forms of electronic commerce, cross-border e-commerce provides numerous consumer benefits, such as broad and deep product assortments at low prices. However, consumers tend to exhibit high involvement in cross-border e-commerce purchases due to high risks associated with such purchases. The paper focuses on identifying causal relationships between e-commerce website traits (i.e., website trustworthiness, interactivity and convenience) and consumer satisfaction and along with loyalty. We proposed a reflective-reflective hierarchical model (first-order reflective and second-order reflective model) and used the Partial Least Square Analysis Statistical method to test the hypotheses. The results demonstrated that website trustworthiness, convenience and interactivity were all positively related to consumer satisfaction. Also, higher satisfaction led to stronger customer loyalty, which may well increase revisit intentions. We also compared the strength of each path from a website trait to satisfaction. Results illustrated that the path from website convenience to satisfaction is the strongest among the three website traits. In addition, we separately examined differences within Korean group and Chinese group. No statistically significant difference among website traits was found within Korean group. However, within Chinese group, we found that website convenience is the most important predictor of satisfaction. This indicates that Chinese consumers are more concerned about the website convenience than interactivity and trustworthiness when they make cross-border e-commerce purchases. Moreover, this study investigated possible differences between Korean and Chinese group. We used multi-group analysis of Smart PLS 3.0 to test the results. It was shown that the two groups do not display statistically significant difference in trustworthiness, interactivity, or convenience in influencing customer satisfaction. Finally, we presented further implications which are useful for understanding of the proposed model. Limitations and improvements of this research were presented, too.

• Advances in Computational Design
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• v.7 no.4
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• pp.321-343
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• 2022

Museum buildings display artefacts for public education and enjoyment, ensuring their long-term safety and the comfort of visitors by following strict indoor environment control protocols using mechanical Heating, Ventilation and Air Conditioning (HVAC) systems to keep the (environmental) variables at a fixed comfort level. Maintaining this requires constant supply of energy currently mostly sourced from the combustion of fossil fuels which exacerbates climate change. However, a review on the effects of the indoor environmental variables on museum artefacts as well as museum visitors revealed that there is no specific point at which artefact deterioration occurs, and that there are wide ranges of conditions that guarantee the long-term safety of artefacts and human comfort. Visits to museum buildings in hot-humid tropical climate of Nigeria revealed that strict indoor environmental practices were adopted. Even when appropriate micro-climatic conditions are provided for artefacts, mechanical HVAC systems remain necessary for visitor comfort because almost no consideration is given to natural ventilation. With the current global push towards energy management, this paper reviewed passive environmental control practices, architectural design strategies, and discusses the adaptation of double skin façade with jali screens, and the notion of smart materials, which can satisfy the range of requirements for the long-term safety of artefacts and levels of human comfort in buildings in hot-humid tropical climate, without mechanical HVAC systems. This review would inspire more discussions on passive, energy efficient, smart and climate responsible popular architecture, challenging current thinking on the impact of the more accepted representative architecture.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.2
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• pp.70-75
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• 2022

With the spread of various digital devices, devices have become commonplace in modern society. Moreover, due to the increase in device usage and online learning while staying indoors during the COVID-19 pandemic, symptoms such as an increase in myopia in children due to eye fatigue, an increase in young presbyopia, and dry eye syndrome are increasing, and now people are paying attention to eye health. This is different from before. There are various prescriptions for eye health, but in this paper, we would like to propose a training method for enhancing visual function using VR contents. The analog methods of the existing teaching aids for visual function reinforcement training were planned and produced as digital contents, and VR-based training contents were selected from among the various methods carried out with teaching aids at the visual function training center, which can be made into contents. was developed with In the training process for each content, it was proposed to apply eye tracking to the VR device in order to give the user feedback on their participation in the training so that the management and concentration of the training process could be analyzed.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.268-272
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• 2023

With the development of SNS, companies and individuals are actively marketing through social media to develop their own products. It is also important to post posts promoting on simple SNS or to show a lot of exposure using algorithms, but customers upload reviews or proof shots of the product on their own, naturally increasing the exposure of the product and increasing the purchasing power of potential customers. As the number of products that users want to purchase through SNS is increasing, they want to access and purchase not only tangible products such as goods and food, but also intangible services through SNS. In this paper, we would like to study exhibitions that have both tangible and intangible characteristics. SNS accounts that mainly introduce these products by searching for reviews have been created while spending leisure time such as exhibitions and fairs, reducing the hassle of searching for personal interests on search engines, and providing prices and reviews from the exhibition's schedule, lowering entry barriers and increasing purchasing power. Using this point, many exhibitions not only display works, but also open various experience centers, and create a photo zone or a unique exhibition hall atmosphere to attract many customers. In this study, we study the impact of SNS on the leisure culture of exhibition. The marketing direction in the situation where SNS marketing is becoming the mainstream is presented, and the change in the form of exhibition is described and presented as an academic approach.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.2
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• pp.109-115
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• 2023

In this paper, we demonstrated the orientation characteristics of liquid crystals using UV-treated FSAM as alignment layer. Moreover we confirmed the FSAM properties before and after UV treatment on indium tin oxide (ITO) glass substrates using physicochemical analysis. The hydrophobic property of the FSAM surface is change to hydrophilic through UV treatment. After UV treatment the LC molecules also were uniformly and horizontally aligned on the FSAM surfaces and the pretilt angle was obviously changed 90° degrees to 0° degrees. EO characteristic of TN cell which was fabricated with UV-treated FSAM was faster response time compare to conventional PI layer. The FSAM before and after UV treatment has a superior application potential as the LC alignment layer for LCD, potentially replacing the conventional polyimide layer.

• Smart Media Journal
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• v.11 no.2
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• pp.18-24
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• 2022

Problems caused by malicious comments occur on many social media. In particular, YouTube, which has a strong character as a medium, is getting more and more harmful from malicious comments due to its easy accessibility using mobile devices. In this paper, we designed and implemented a YouTube malicious comment detection system to identify malicious comments in YouTube contents through LSTM-based natural language processing and to visually display the percentage of malicious comments, such commentors' nicknames and their frequency, and we evaluated the performance of the system. By using a dataset of about 50,000 comments, malicious comments could be detected with an accuracy of about 92%. Therefore, it is expected that this system can solve the social problems caused by malicious comments that many YouTubers faced by automatically generating malicious comments statistics.