• Journal of Korean Ophthalmic Optics Society
• /
• v.6 no.1
• /
• pp.31-35
• /
• 2001

We have studied the auto-lensometer for several years in order to begin korean-made production of it and then developed the auto-lensmeter using with the personal computer. We introduce the most important principal of PSD device and the optical principal of measuring the power of the refraction of the lens by auto-lensometer and also explain the fabrication of the LED optical source system and PSD optical system. Finally, we found the power constant of our auto-lensmeter to be about 30 Diopter/mm.

• Korean Journal of Optics and Photonics
• /
• v.35 no.4
• /
• pp.135-142
• /
• 2024

Biomedical imaging technologies refer to imaging techniques used in biological research and medical technology that are essential for exploring biological processes, structures, and conditions. They also play a crucial role in the early diagnosis of diseases and the development of treatments. Optical imaging technologies, in particular, are the most widely used and actively researched in biological studies. The major obstacles to technological advancement are the limitations in resolution and light penetration depth. Recently, many technologies have been studied to overcome these limitations using metamaterials. These are materials that can freely manipulate the properties of light through the regular arrangement of nanostructures and have established themselves as innovative tools in the imaging field. This article aims to provide a detailed introduction to the working principles and key applications of these technologies.

• Journal of Korean Ophthalmic Optics Society
• /
• v.10 no.4
• /
• pp.261-266
• /
• 2005

Quaternary ammonium compounds(QACs) are some of the most commonly used antimicrobials. Antimicrobial polymers have been used as biomedical devices. In this Study, We synthesized new methacrylate monomers including quaternary ammonium moieties for preparation of contact lens, And also, we tested for antimicrobial activities against S. aureus, E. coli and P. aeruginosa. They showed much higher antimicrobial activities against all than the polymers of no including quaternary ammonium.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2022.07a
• /
• pp.577-580
• /
• 2022

본 논문에서는 마이크로소프트(Microsoft, MS) 홀로렌즈v2를 이용하여 물리 기반 애니메이션은 유체와 로프를 제어할 수 있는 새로운 방법에 대해 소개한다. 물리 기반 시뮬레이션 혼합현실, 메타버스, 게임 등 다양한 콘텐츠에서 몰입감을 개선하기 위해 활용되고 있는 기술이다. 하지만, 계산양이 크고 사용자가로 인한 직관적인 제어 시스템의 부재로 많은 시장에 활용되기에는 어려운 구조이다. 이러한 문제를 완화하기 위해 본 논문에서는 혼합현실 환경에서 무선으로 사용자 인터페이스를 구현한 홀로렌즈v2를 이용하여 물리 애니메이션을 제어하고자 한다. 이러한 도전은 혼합현실에서도 사용자의 손동작, 음성, 눈 추적 등 다양한 인터페이스를 통해 시뮬레이션을 제어할 수 있다는 가능성을 열어줌으로써, 관련시장도 확장 될 수 있다. 본 논문에서는 대표적으로 유체와 로프 시뮬레이션을 홀로렌즈를 통해 제어하는 결과를 보여준다.

• Journal of Broadcast Engineering
• /
• v.27 no.5
• /
• pp.728-737
• /
• 2022

Metaverse is gaining worldwide interest, and related industries are developing rapidly. In the field of education, students' interest in metaverse is increasing, and education on metaverse-related technologies and services is required. However, since metaverse classes in universities mainly consist of theoretical education and domestic/overseas case analysis education, practical education that can apply metaverse technology to the real world is also necessary. In the cultural field, event contents such as entrance ceremonies and exhibitions are mainly produced for metaverse contents, and it is also necessary to study metaverse contents that can be sustained for a long time by people visiting regularly. In this study, educational contents that can link cultural participation in the real world with cultural participation in the metaverse were studied using the local cultural space as a medium to produce sustainable metaverse contents. The 'Metaverse Moonshin Art Museum commemorating the 100th anniversary of Moonshin's birth' program reinterpreted the real world of Changwon Moonshin Art Museum into a virtual world by collaborating with students on the Roblox. The 'Expanded Reality Moonshin Art Museum' program created an expanded Metaverse art museum that transcends time by augmenting the deceased Moonshin artist in the museum's exhibition space using HoloLens. For students studying culture-related majors, an educational program that combines metaverse education and practical training was conducted, and it is planned to be supplemented and used as a teaching plan.

• Knowledge Management Research
• /
• v.23 no.2
• /
• pp.15-35
• /
• 2022

With the development of virtual and augmented reality technologies, the metaverse, a digital world that provides an immersive feeling like the real world, is overgrowing. Many IT companies such as Naver, Facebook (Meta), and NVIDIA are developing innovative technologies and launching the Metaverse platform and related products on the market. However, even though it is a new business in which many global big tech companies are aggressively investing, the results are not yet precise compared to the market expectations, and the rate of increase in the number of users is gradually slowing down. This can be attributed to the lack of consideration and understanding about how to grow the metaverse ecosystem and operate & harmonize various users/components from the time the metaverse platform was designed. In order to propose a better solution to these problems, this study adopts the yin-yang and five elements theory, which was created to understand the operation logic and logic of the human world for thousands of years. This research would like to propose a theory of double lines-five elements by defining two essential spaces of the metaverse platform, online and offline, and five essential elements constituting the metaverse platform. This study intends to provide a theoretical lens on how to design and operate a platform through the double lines and five elements theory and the concept of coexistence and polarity between the five elements.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.1
• /
• pp.499-505
• /
• 2022

Recently, the metaverse has been receiving a lot of attention. Metaverse means a virtual space, and various events can be held in this space. In particular, 360-degree video, a format optimized for the metaverse space, is attracting attention. A 360-degree video image is created by stitching images taken with multiple cameras or lenses in all 360-degree directions. When shooting a 360-degree video, a variety of shooting equipment, including a shooting staff to take a picture of a subject in front of the camera, is displayed on the video. Therefore, when shooting a 360-degree video, you have to hide everything except the subject around the camera. There are several problems with this shooting method. Among them, lighting is the biggest problem. This is because it is very difficult to install a fixture that focuses on the subject from behind the camera as in conventional image shooting. This study is an experimental study to find the optimal angle for 360-degree images by adjusting the angle of indoor lighting. We propose a method to record 360-degree video without installing additional lighting. Based on the results of this study, it is expected that experiments will be conducted through more various shooting angles in the future, and furthermore, it is expected that it will be helpful when using 360-degree images in the metaverse space.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.525-528
• /
• 2003

The aspherical lens are used as objective lens of optical pickup. The sample product is made before manufacturing the injection mould of lens to examine the design factor. The optimum cutting conditions of the main spindle speed, the depth of cut, the feed rate are found when we cut PMMA and PC lens sample with ultra-precision SPDT. The demanded surface roughness 10 nm Ra. aspherical form error 0.5 ${\mu}{\textrm}{m}$ P-V for aspherical lens of optical data storage device are satisfied for PMMA. but not satisfied for PC.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.14 no.3
• /
• pp.36-42
• /
• 2015

The aspherical lens was designed to be able to array a focal point. For this reason, it has very curved surface. The aspherical lens is fabricated by injection molding or diamond turning machine. With the aspherical lens, tool marks and surface roughness affect the optical characteristics, such as transmissivity. However, it is difficult to polish free form surface shapes uniformly with conventional methods. Therefore, in this paper, the ultra-precision polishing method with MR fluid was used to polish an aspherical lens with 4-axis position control systems. A Tool path and polishing mechanism were developed to polish the aspherical lens shape. An MR polishing experiment was performed using a generated tool path with a PMMA aspherical lens after the turning process. As a result, surface roughness was improved from $R_a=40.99nm$, $R_{max}=357.1nm$ to $R_a=4.54nm$, $R_{max}=35.72nm$. Finally, the MR polishing system can be applied to the finishing process of fabrication of the aspherical lens.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.13 no.1
• /
• pp.92-99
• /
• 2014

An aspherical lens, which resolves several problems with a spherical lens,typically serves asa key part of an optical system. Generally, an aspherical lens is fabricated using a diamond turning machine or by mean of injection molding. However, residual stress and/or tool marks can arise when using a commercial fabricating method such as DTM or injection molding. A polishing process, thus, is commonly used to obtain a high-precision aspherical lens. In this study, a polishing method using MR fluid was applied to minimize several problems, in this case residual stress and the creation of tool marks, during the cutting process. The MR polishing system was developed to polish aspherical lenses. A series of experiments were performed to obtain a very fine surface roughness. PMMA (the lens material for molding) was used as a workpiece, and the gap size, magnetic field intensity, wheel speed and feed rate were selected as the parameters in this study. Finally, a very fine surface roughness of Ra=2.12nm was obtained after MR polishing.