• Convergence Security Journal
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• v.3 no.1
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• pp.59-72
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• 2003

Recently, the studies of contents protection technique are getting popular in the field of internet DRM(Digital Right Management). But, authentication process of digital contents is different from each implementation. Also, protection technique for the contents rights intrusion adapts each other methodologies. We survey the modeling and system of DRM such as DOI, INDECS, MPEG-21, XrML, and OPIMA standard in this paper.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.299-303
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• 1993

There can be two methods in control systems: one is to use a linear controller, the other is to use a nonlinear controller. The PID controller and the fuzzy controller can be said to belong the linear and the nonlinear controller respectively. In this paper, a new hybrid controller which is consist of the linear PID controller of which the gain is tuned and the nonlinear self tuning fuzzy controller is proposed. In the PID controller, an algorithm which parameterizes the proportional, the intergral, and the derivative gain as a single parameter is used to improve the performance of the PID controller. In the self tuning fuzzy controller, an algorithm which changes the shape of the triangle membership function and changes the scaling factor which is multiplied to the error and the error change. The evaluation of the performance of the suggested algorithm is carried on by the simulation for the Rhino XH-2 robot manipulator with 5 links revolute joints.

• Proceedings of the Korea Society for Simulation Conference
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• 2003.06a
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• pp.79-84
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• 2003

이 논문은 빠른 ASIP(application specific instruction processor) 평가를 위한 재적응성을 가진 컴파일러/시뮬레이터 환경에 대해 이야기한다. ASIP의 성능은 하드웨어 구조뿐만 아니라, 수행되는 응용 소프트웨어에 영향을 받기 때문에, 높은 성능의 ASIP 개발을 위해서는 컴파일러 및 시뮬레이터의 개발이 선행되어야 한다. 그러나 다양한 ASIP 구조에 따라 적합한 고성능의 컴파일러/시뮬레이터를 만드는 일은 매우 시간 소모적인 일이 될 뿐만 아니라, 오류가 발생하기도 쉽다. 본 논문에서는 HiXR2라는 ADL(architecture description language)을 이용하여 명령어 구조를 기술하고 이를 바탕으로 컴파일러와 시뮬레이터를 자동 생성하였다. HiXR2의 재적응성 및 생성된 컴파일러/시뮬레이터의 정확성을 검증하기 위하여 ARM9 프로세서와 CalmRISC32 프로세서 구조를 각각 기술하고, 각각에 대하여 응용프로그램 코드를 컴파일 및 시뮬레이션 하는 예제를 보였다.

• Journal of the Korea Society for Simulation
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• v.12 no.2
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• pp.45-53
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• 2003

This paper presents a retargetable compiled assembly simulation technique for fast ASIP(application specific instruction processor) simulation. Development of ASIP which satisfies design requirements in various fields of applications such as telecommunication, wireless network, etc. needs formal design methodology and high-performance relevant software environments such as compiler and simulator In this paper, we employ the architecture description language(ADL) named ${HiXR}^2$ to automatically synthesize an instruction-level compiled assembly simulator. A compiled simulation has benefit of time efficiency to interpretive one because it performs instruction fetching and decoding at compile time. Especially, in case of assembly simulation, instruction decoding is usually a time-consuming job(string operation), so the compiled simulation of assembly simulation is more efficient than that of binary simulation. Performance improvement of the compiled assembly simulation based on ${HiXR}^2$ is exemplified with an ARM9 architecture and a CalmRISC32 architecture. As a result, the compiled simulation is about 150 times faster than interpretive one.

• Electronics and Telecommunications Trends
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• v.37 no.4
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• pp.81-88
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• 2022

In this study, we investigate the trends and prospects of spatial light modulation (SLM) technology that enables full complex modulation as a next-generation SLM. Current SLM technology, which is used as a key element in holography, augmented reality (AR), XR, and realistic displays, has performance limits that modulate only amplitude or phase. Notably, SLM capable of full complex modulation does not produce diffraction noise, unlike DC and twin image, and thus has a high-efficiency performance. In the future, the application field of next-generation SLM, which can be full-complex modulated, is expected to cover a wide range of holography-AR and-XR devices, optical artificial intelligence, and 6G free space optics communications, which will greatly contribute to the development of a super-realistic metaverse platform and service.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.633-635
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• 2021

현재 코로나 19로 인한 각종 지역특산품 축제가 축소 및 취소되어 지역발전에 저해 요인을 해결할 대책이 필요하다. 기존 특산품 축제의 문제점은 상품 품질의 우수성은 있지만, 접근성에 어려움이 있고 지속적인 정부의 방역지침으로 대면이 필수적인 특산품 경제에 타격을 입는다. 본 논문에서는 해당 문제를 해결하기 위해 비대면 메타버스형 VR 기술을 접목한 지역경제 및 관광 활성화를 제안한다. 해당 솔루션은 포톤서버를 활용한 실감형 체험 및 멀티접속을 구현하고 VR-Chatting 기술을 활용하여 대화로 시장 상품을 의견조율 가능한 시스템을 구현하였으며, 3D 아바타 모델링 기술을 활용해 지역별 특성화 캐릭터 제작 및 지역특산품 홍보로 기존 특산품 축제의 문제점을 해결하는 솔루션을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.43-44
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• 2020

최근 케이팝 문화의 확산으로 한류라는 브랜드가 구축되고, 이에 관심이 급증함에 따라 관련 콘텐츠 시장의 혁신이 요구되고 있다. 본 논문은 한류문화 전수를 위한 수퍼인텔리전스 기반의 확장현실(XR) 소프트웨어 플랫폼에 관한 것으로, 본 플랫폼을 통하여 한류 문화 체험 및 전수가 가능하다. 세부적으로는 한류 콘텐츠 전수를 위한 확장현실 기반 공간을 바탕으로 딥러닝 기반 영상 생성 및 동작 분석기술, 자동 음악생성 기술, 한류 문화 데이터 보안 기술을 포함한 통합적인 플랫폼 환경을 설계하여 제안한다. 또한 이 플랫폼의 3차원 동작 분류 및 예측을 향상 시킬 수 있는 방법을 제안한다.

• Journal of radiological science and technology
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• v.38 no.1
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• pp.51-61
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• 2015

Computed tomography(CT) using radiation have potential risks. All medical radiographic examinations should require the justification of medical imaging examinations and optimization of the image quality and radiation exposure. The CT examination was higher radiation dose then general radiography. Especially pediatric CT examinations need to great caution of radiation risk. Because of pediatric patient was more sensitive of radiation exposure. Therefore, physician should consider the knowledge of CT radiation exposure indicator information for reduce a needless radiation exposure. This article was aim to understanding of CT exposure indicator, size-specific dose estimates by American Association of Physicists in Medicine (AAPM) report 204, XR 25 and understanding of CT dose reduction technique.

• Journal of the Korea Society of Computer and Information
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• v.25 no.8
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• pp.23-30
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• 2020

As the 4th industrial revolution emerged, the latest technologies such as IoT, AI, Big data, AR/VR/XR are emerging. However, in the field of virtual reality (VR) technology platform services, there is no standardization and systematic support. In addition, various platform technologies related to virtual reality have been presented, making it difficult to select an API that should be selected for development. In this study, we analyzed the method for virtual reality development and the virtual reality (VR) technology that is being serviced by users. In addition, by presenting the advantages and disadvantages of each development platform, we intend to present a reference point for developers to select an efficient platform. In addition, it will help the developer to select an effective equipment and software platform in comparison with the advantages and disadvantages of various HMD devices used in virtual reality. The virtual reality (VR) development environment test used products from Oculus, and the software development environment was tested with two types: WebBased VR and HMD embedded.

• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.27-37
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• 1993

The purpose of this study was to determine the fluroide release levels of new fluoride-containing liner/base cements and the fluoride uptake by dentin surfaces. Ten specimens of each brand (Fuji ionomer Type III, Fuji Lining LC, Timeline, Vitrebond and XR ionomer) were made, polymerized and placed in fluoride-free distilled water at $37^{\circ}C$, 100% relative humidity for 24 hours. The extracting solution of specimen was exchanged and fluoride release was measured daily for the 30 days. For fluoride uptake study, twenty-five extracted human lower molars were sectioned longitudinally in the mesiodistal direction with a diamond disc. Five teeth were filled with each material and then stored at $37^{\circ}C$, 100% humidity for 4 weeks. Fluoride uptake by dentin from the test materials was evaluated using electron probe micro X-ray analyzer. The following results were obtained : 1. The amounts of fluoride release showed no significant difference between Fuji ionomer Type III and Fuji Lining LC, but showed significant difference between other groups. XR ionomer released significantly greater fluoride than any other group(P<.001). 2. All the materials have a burst effect which more fluoride released in then first 3 day and showed significant decrease over the test period (P<0.001). 3. XR ionomer group showed fluoride penetration to approximately $50{\mu}m$ deep in dentin. But other material groups showed very little fluoride uptake by dentin.