• Journal of Conservation Science
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• v.25 no.4
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• pp.363-371
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• 2009

This study is purposed to investigate that current rubbing technique could be replaced by the photographic rubbing techniques with the photographic lighting and digital techniques. The lighting technique is based on the "texture description theory" using the electric flash and the intaglio epitaph was emphasized from the observation of the both side because it is purposed to decipher epitaph. The photographs were retouched using the photoshop to emphasize epitaph and the spots from the lichen on the tombstone were softened. Especially, it shows that faint epitaph could be deciphered if the digital techniques could be used practically even though some part of the epitaph was destroyed or peeled. Furthermore, it will help to investigate, protect and restore the cultural properties because it surely makes the recording of the material, weathering, peeling of the tombstone much easier than the current rubbing technique.

• Digital Contents
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• no.7 s.146
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• pp.66-71
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• 2005

교육(Education)과 오락(Entertainment)의 합성어인 에듀테인먼트(Edutainment)는 학생이 학습을 하거나 기업의 종업원이 특정 능력을 익히는 데 사용되는 교육용 도구를 의미한다. 에듀테인먼트는 교육용 소프트웨어에 게임이나 친근한 인물과 음악, 이야기 등 오락성을 가미해 싫증을 느끼지 않고 즐기면서 교육적 효과를 거두고자 하는 목표를 지향하고 있다. 이러한 재미와 교육이라는 두가지 목표를 달성하기 위해 에듀테인먼트에 포함되는 디지털콘텐츠는 게임이나 e러닝의 콘텐츠와는 다른 차원의스토리텔링 기법이 요구된다. 이번호에서는 에듀테인먼트 콘텐츠에 적합한 퀘스트 스토리텔링(Quest Story telling)과 공간 스토리텔링(Spatial Storytelling)을 소개한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.11b
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• pp.246-249
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• 2002

디지털 워터마킹 기법 평가를 위한 다양한 시도가 행해지고 있다. 특히 디지털 영상에 대한 공격기법을 도구화한 것중에 Matlab으로 구현된 Checkmark가 개발되어 있다. 특히 디지털 영상에 대한 워터마킹 수행모듈(삽입, 추출포함)은 평가를 위한 공격모듈과 별개로 분리할 수밖에 없는 실정이었다. Checkmark는 특별히 워터마킹의 추출과정을 사용자가 설정하여 Checkmark 수행 모듈에 포함시킬 수 있도록 배려하였다. 이러한 시도는 새로운 워터마킹 알고리즘의 개발 과정에 상당히 효율적인 부분이라고 할 수 있다. 본 논문은 이러한 점을 중심으로 Checkmark의 사용자 설정 모듈을 소개하고자 한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.861-866
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• 2002

디지털 데이터의 저작권 보호를 위하여 최근 디지털 워터마킹에 관하여 많은 연구가 이루어지고 있다. 저작권 보호를 위해 멀티미디어 컨텐츠에 인지되지 않도록 기밀정보를 삽입하는 기술을 워터마킹이라고 하고 삽입되는 마크를 워터마크라고 한다. 본 논문에서는 DCT-Block을 이용한 디지털 워터마킹 기법을 제안한다. 이 기법을 이용하여 의사난수형의 잡음신호를 눈에 보이지 않도록 삽입하고, Stirmark공격에 강인하도록 구성하였다. 성능을 평가하기 위하여 영상에 워터마크를 삽입하고 각종 공격을 가하여 그 유효성을 보인다.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2251-2253
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• 2004

본 논문은 선형 행렬 부등식 기반의 디지털 재설계 기법의 점근적 성질을 논의한다. 이를 위하여 델타 작용소를 기반한 디지털 재설계 기법을 제안한다. 샘플링 주기의 감소에 따른 재설계된 디지털 제어기의 성능회복을 증명한다.

• Journal of Veterinary Clinics
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• v.29 no.1
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• pp.18-22
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• 2012

This study was performed to evaluate the sensitivity of conventional film-screen radiography (CFSR) and direct digital radiography (DDR) for detection of various amounts of free peritoneal fluid. Ten adult male healthy beagles were used in this study. Radiographic examinations were performed in the right lateral and ventrodorsal positions. Fluid was injected in increments of 2.0 ml/kg of body weight up to 20.0 ml/kg of body weight. The images of CFSR and DDR were evaluated by two veterinary radiologists for evidence of abdominal fluid without knowledge of injected fluid volume. Data were evaluated by using the receiver operation curve (ROC) analysis and the area under the curve (AUC). There was no significant difference in detection of peritoneal fluid between DDR and CFSR in the ROC analysis. The accuracy of CFSR (0.805) was relatively higher than that of DDR (0.733), based on the ROC analysis and AUC. AUC of CFSR was higher in most injection doses. These results suggest that CFSR is more accurate than DDR for the detecting peritoneal fluid. Therefore, for situation in which digital radiographs are equivocal or small amount of fluid is suspected, other imaging modalities, such as ultrasonography would be helpful for determining the presence of fluids.

• Journal of KIISE:Databases
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• v.37 no.6
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• pp.292-299
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• 2010

Recently, as flash memory is used as digital storage devices, necessity for digital forensics is growing in a flash memory area for digital evidence analysis. For this purpose, it is important to recover crashed files stored on flash memory efficiently. However, it is inefficient to apply the hard disk based file recovery techniques to flash memory, since hard disk and flash memory have different characteristics, especially flash memory being unable to in-place update. In this paper, we propose a flash-aware file recovery technique for digital forensics. First, we propose an efficient search technique to find all crashed files. This uses meta-data maintained by FTL(Flash Translation Layer) which is responsible for write operation in flash memory. Second, we advise an efficient recovery technique to recover a crashed file which uses data location information of the mapping table in FTL. Through diverse experiments, we show that our file recovery technique outperforms the hard disk based technique.

• The Transactions of the Korea Information Processing Society
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• v.13 no.2
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• pp.26-33
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• 2024

There has been a recent surge of interest in the Digital Twin technology. The Digital Twin is technique for optimizing objects by simulating physical phenomena or objects through computer-based simulations. Currently, single Digital Twin is being developed to optimize processes limited to specific fields, but there is a limitation in that the independent Digital Twins cannot analyze the vast and complex processes of the real world. To overcome this, the concept of federated Digital Twin has been introduced. To date, the federated Digital Twin research has primarily focused on how to optimize macroscopic objects such as cities. However, by leveraging the interconnected nature of twins, existing implementations of the single Digital Twins can be modularized. In this study, we define the concepts and interrelationships of the single Digital Twin and the federated Digital Twin from a functional perspective related to process optimization and design a modularization technique for the single Digital Twin using the federated Digital Twin. Furthermore, this study aims to discuss the proposed methodology's efficacy by designing a model applying modularization to a real-world fabric manufacturing case.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.18-21
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• 2011

디지털 홀로그램은 일반적으로 computer generated hologram(CGH)기법에 의해서 생성된다. 하지만 원리적으로 CGH 기법은 많은 연산량과 복잡도를 요구하고 있기 때문에 실시간으로 디지털 홀로그램을 생성하는 것은 매우 어렵다. 본 논문에서는 CGH 고속연산을 위해 graphics processing unit(GPU)의 병렬처리구조인 CUDA를 사용하였고, 추가적으로 다중 GPU 연산처리를 위해 OpenMP를 사용하였다. 더 나아가 이를 최적화하기 위해서 상수화, 벡터화, 루프풀기 등의 기법들을 제안한다. 결과적으로, 본 논문에서 제안된 기법을 통해서 기존 CPU에서의 CGH 연산속도에 비해 약 8,300배 정도의 속도를 개선할 수 있었다.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.877-881
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• 2002

Digital contents such as image need both secure proving and publicly verification scheme on embedded digital watermark for contents distribution and copyright protection. Specially, we must provide publicly verification mechanism on digital watermark without revealing any of the secret information hidden on digital contents. In this paper, we review on the existing zero knowledge proofs and digital watermarking system, and propose advanced interactive zero knowledge proofs mechanism for enhancing the performance and security of watermark verification process. And it Provides a new watermark verification scheme without revealing any secret on the contents owner's copyright in formation.