• ETRI Journal
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• 제26권6호
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• pp.653-656
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• 2004

This paper presents an effective algorithm for inserting an MPEG-2 transport stream (TS) into a Digital Audio Broadcasting (DAB) ensemble without any bandwidth waste in a Digital Multimedia Broadcasting (DMB) transmission system. The key technologies of this algorithm include packet rate control and program clock reference correction, which are important for TS processing. The proposed algorithms are applied to the various DMB transmission systems based on Eureka-147, and the performance of the proposed algorithm is confirmed through the experimental DMB broadcasting.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.110-114
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• 2003

In this paper, a new self-oscillated type high voltage charger controller circuit is proposed, which has variable constant current source characteristics to improve charge characteristic of charger roller. The proposed control method enables high quality printing characteristics regardless of the circumstance change such as ambient temperature or humidity by changing the current reference signal. To verify the proposed control method various experiments are performed.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.244-251
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• 2011

We propose a new 2-step phase-shifting digital holographic optical encryption technique and analyze tolerance error for this cipher system. 2-step phase-shifting digital holograms are acquired by moving the PZT mirror with phase step of 0 or ${\pi}$/2 in the reference beam path of the Mach-Zehnder type interferometer. Digital hologram with the encrypted information is Fourier transform hologram and is recorded on CCD camera with 256 gray-level quantized intensities. The decryption performance of binary bit data and image data is analyzed by considering error factors. One of the most important errors is quantization error in detecting the digital hologram intensity on CCD. The more the number of quantization error pixels and the variation of gray-level increase, the more the number of error bits increases for decryption. Computer experiments show the results to be carried out encryption and decryption with the proposed method and the graph to analyze the tolerance of the quantization error in the system.

• 대한공간정보학회지
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• 제7권2호
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• pp.81-91
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• 1999

지형공간정보체계의 운영을 위하여 필수적인 자료기반의 갱신을 위한 연구가 활발히 진행되고 있다. 본 연구에서는 수치 사진측량과정에 의하여 취득되는 자료를 활용하여 정사투영영상을 생성하고 영상피라미드 기법을 이용하여 다축척 정사투영영상지도를 제작하였다. 연구의 결과 제작된 정사투영영상지도의 정확도는 1:5,000 지형도 대비 2.092m의 정확도로서, 다양한 지형공간정보체계 자료기반 자료취득이 가능하였다.

• 한국실내디자인학회논문집
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• 제15권2호
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• pp.118-126
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• 2006

This study aims at analyzing the characteristics and trends of future workplace in reference to the case for Digital Nomad Space (DNS). For this study, it has been investigated how to converge meanings of the digital environment and physical office space by which surveys to potential digital nomads were fulfilled. As a result, the types and the properties of future workplace in digital environment have been obtained. This study also includes general characteristics and design aspects of the time-based ubiquitous rental workplace followed by investigating future trends of the digital era. Thus, suggestions of spatial requirements of the digitalized office towards the practical level in the architectural interior design is proposed, and DNS has special features such as the cultural complex and ICT-based facilities with free accessibility to existing information and data over the air.

• 대한전자공학회논문지SD
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• 제41권2호
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• pp.17-25
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• 2004

디지털 흘로그래픽 정보 저장을 위한 새로운 데이터 매트릭스 구조와 이 구조를 통해 정보 추출할 수 있는 알고리즘을 제안하고 구현하였다 제안된 데이터 매트릭스 구조는 실제 사용자 정보와 기하학적 변형에 따른 raw BER을 줄이기 위한 참조 격자로 이루어져있고, 정보를 추출하는 알고리즘은 찬조격자의 위치를 판별하고 이 정보로부터 실제 사용자 정보를 추출하는 구조로되어 있다. 실험 결과 영상 이동, 회전, 배율변화에 대해 각각 3.09×10-18, 6.14×10-12, 1.2×10-7 의 평균 raw BER을 얻음으로서, 기하학적 변형에 대한 우수한 검출특성을 갖고 있음이 증명되었다.

• 한국도서관정보학회지
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• 제48권4호
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• pp.129-151
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• 2017

현재 디지털 아카이빙에 널리 적용되고 있는 정보 모델링에서는 기술사항 생성을 위한 개념적인 프로세스만을 정의하고 있으며, 이를 정보자원의 보존 혹은 보존을 위한 메타데이터의 생성에 실제적으로 적용하는데 있어서는 한계를보이고 있다. 이에 본 연구에서는 디지털 아카이빙에서의 정보 개체를 효율적으로 기술하기 위해 정보자원 클러스터의 개념을 제안하고, 이를 실제적으로 구현하기 위해 XML 구문에 기반한 RDF를 적용하여 보존 기술항목 프레임워크를 구축하였다. 이는 OAIS 참조모델과 FRBR의 개념적인 구조를 결합하여 보존의 대상이 되는 정보자원을 보다 효과적으로 기술하고 보존 메타데이터를 생성할 수 있는 대안적인 접근방법으로 활용될 수 있을 것으로 기대된다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.346-350
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• 2009

Digital Multimedia Broadcasting (DMB) is the mobile TV service based on a digital radio transmission system that provides high quality audio/video and other auxiliary data services. As users want to store the DMB content in their device to be consumed later or to be shared among users, a standardized format needs to be specified to guarantee the interoperability for the DMB contents for various devices. DMB AF (Application Format) specification defines a file format for DMB contents and services. It specifies how to combine the variety of DMB contents with associated information for a presentation in a well-defined format that facilitates storage, interchange, management, editing, and presentation of the DMB contents in protected, governed, and interoperable ways. In this paper we present our implementation of DMB AF as part of the development of DMB AF reference software. Our implementation of DMB AF is developed as the reference software for the standard specification that consists of a three applications: packager, media player, metadata browser and collection of supporting libraries used by the applications.

• 한국광학회지
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• 제14권2호
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• pp.200-207
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• 2003

본 논문에서는 기존의 위상천이 디지털 홀로그래피에서 기준빔으로 사용되는 평면파 대신 보다 일반적인 구면파를 이용하여 3차원 공간상에 위치한 두 물체점들 사이의 상대적인 거리를 측정하는 새로운 시스템 및 알고리듬을 제안한다. 본 논문에서는 이러한 시스템에 대한 모의실험 및 광학실험을 실시하였다. 이러한 시스템에서는 홀로그램 기록에 사용된 기준빔의 정확한 정보를 알고 있지 않더라도 3차원 공간상의 두 물체점들 사이의 상대적인 거리를 정확하게 측정할 수 있다. 본 논문에서는 광학실험을 통하여 약 300 cm 거리에서 서로 0.5 cm 떨어진 두 물체점들 사이의 상대적인 거리를 10% 미만의 오차로 측정하였다.

• International Journal of Knowledge Content Development & Technology
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• 제8권2호
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• pp.49-65
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• 2018

Are the benefits derived from ICT based reference and information service worth the financial and other commitments devoted to it? In an attempt to answer this, this study delved into finding out the perceived benefits; the rational for ICT based reference services in Nigerian university libraries. The main objectives were to find out the purposes for using ICT facilities in reference services delivery and the perceived benefits derived from using ICT resources in reference and information services. Being a survey, questionnaire was used to collect data from the librarians of twelve (12) universities; two (2) each sampled from the six geopolitical zones of Nigeria. Data was analyzed using frequencies, mean scores and standard deviations. ANOVA statistical analysis was used to test the hypothesis of no significance difference in the benefits derived from ICT based reference services using p-value of 0.05 to calculate the level of significance. Findings showed that librarians and library users made use of ICT facilities for different reference purposes especially to obtain information they need using the internet. Other reference needs for which patrons used the ICT facilities included: - access to current e-books and e - journals, user education and access to global information in other libraries. Provision of current awareness services (CAS) and selective dissemination of information services (SDI), on-line searching using workstations in the library, provision of on-line public access catalogue (OPAC) services, keeping statistics of users of the reference section and compilation of bibliographies. Further findings showed that the librarians and library users derive a lot of benefits from their use of ICT facilities in reference services. The results showed that easy retrieval and dissemination of information to patrons were ranked highest by the librarians amongst others.