• Title/Summary/Keyword: Digital IF

Search Result 2,212, Processing Time 0.029 seconds

Ordinary B-tree vs NTFS B-tree: A Digital Forensics Perspectives

  • Cho, Gyu-Sang
    • 한국컴퓨터정보학회논문지
    • /
    • 제22권8호
    • /
    • pp.73-83
    • /
    • 2017
  • In this paper, we discuss the differences between an ordinary B-tree and B-tree implemented by NTFS. There are lots of distinctions between the two B-tree, if not understand the distinctions fully, it is difficult to utilize and analyze artifacts of NTFS. Not much, actually, is known about the implementation of NTFS, especially B-tree index for directory management. Several items of B-tree features are performed that includes a node size, minimum number of children, root node without children, type of key, key sorting, type of pointer to child node, expansion and reduction of node, return of node. Furthermore, it is emphasized the fact that NTFS use B-tree structure not B+structure clearly.

디지털 중계단에서 랜덤 지터 누적의 수렴을 위한 루우프 여파기의 제한조건 (Constraint Condition of the Loop Filter for the Convergence of Random Jitter Accumulation in Digital Repeater Chain)

  • 유흥균;안수길
    • 대한전자공학회논문지
    • /
    • 제24권4호
    • /
    • pp.548-552
    • /
    • 1987
  • The constraint condition of the loop filter is persented for the convergence of the random jitter accumulation fo the 2-nd order PLL (phase-locked loop) circuit used in digital regenerative repeater. This condition is confirmed under the assumption that the number of repeater chain is 5, bandwidth is 100. 0KHz, the power spectral density of white Gaussian noise is 1.0x10**-6 [W/Hz]. Also, it is shown that if the condition is satisfied, the accumulated random jitter and the alignment jitter will have the saturation characteristics.

  • PDF

Self-Validating 지능형 센서를 사용한 디지털 제어기의 설계 (Design of Digital Controllers with Self-Validating Intelligent Sensors)

  • 나승유;배희종
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
    • /
    • pp.51-54
    • /
    • 2000
  • We are concerned with processing methods of the measurement values of sensors in the control system. When some faults happen to sensor components, the measurement value of sensors cause the malfunction of the plant. So it is necessary to detect and reduce the influence of faults to control with reliability for the overall system. The sensor status must be always good for best demonstration of the controller performance. A self-validating sensor detects the sensor state from the measurement value, reconstruct a soft sensor and can improve reliability of the sensor. If sensor faults, the sensor is detected and reconstructed with the best estimate from its correlation to other sensors and historical data. It is applied to the control of a flexible link system with the sensor fault problems in the light sensor module for position to show the applicability. In this paper, we propose a digital controller which reduces deflection of the moving set-point by reconstructing output of a sensor when the sensor fault is detected.

  • PDF

화상의 작은 영역 변화를 검출 가능한 연성 워터마킹 (Fragile Watermarking to detect change of small range on image)

  • Lee, Hye-Joo;Oh, Yun-Hee;Park, Ji-Hwan;Kim, Kwangjo
    • 한국멀티미디어학회:학술대회논문집
    • /
    • 한국멀티미디어학회 2000년도 추계학술발표논문집
    • /
    • pp.493-497
    • /
    • 2000
  • Fragile watermarking is a technique far autoentication/integrity of digital data. Unlike robust watermarking, il has to design to be vulnerable against some slight processing to verify the modification of digital data. Feature of fragile watermarking is to identify the modifications of data and to locate some places modification occurred at the same time, so it has to identify slight changes of small range if possible. In this paper, fragile watermarking is proposed that the changes of small range on image can be identified using the watermark sequence with period and the values of low bit planes in an image.

  • PDF

DCT 및 분산을 이용한 블라인드 워터마킹 (Blind Watermarking Using DCT and Variance)

  • 신용달
    • 한국멀티미디어학회논문지
    • /
    • 제9권10호
    • /
    • pp.1276-1281
    • /
    • 2006
  • 본 논문에서는 DCT를 이용한 강인한 블라인드 워터마킹 알고리즘을 제안하였다. 제안 방법에서는 $8{\times}8$블록 DCT를 행하였으며, $8{\times}8$블록의 분산, 질감영역 및 평탄영역을 이용하여 워터마크 신호들을 DCT의 직류(DC) 영역에 삽입하였다. DCT를 이용한 디지털 워터마킹 알고리즘에서는 AC 성분보다는 DC성분에서 훨씬 큰 지각 능력을 가지고 있기 때문에 DC 성분에 워터마크를 삽입하면 훨씬 강인해 질 수 있다. 제안 방법의 성능을 확인하기 위해서 컴퓨터 시뮬레이션 수행한 결과, 제안 방법이 기존의 워터마킹 방법보다 JPEG 압축율, Scaling 공격에서 매우 강인함을 확인하였다.

  • PDF

협조적 게임이론을 이용한 국가 간 수산자원관리에 관한 연구 (A Study on the Management of International Fishery Resources using Cooperative Game Theory)

  • 최종두;조정희
    • Ocean and Polar Research
    • /
    • 제30권2호
    • /
    • pp.173-180
    • /
    • 2008
  • This study demonstrates that cooperative management can provide more benefits than noncooperative management for Korea and Japan fishery. We have studied one management strategy, namely, fishing under joint maximization of net benefits in coastal waters of two countries, using a cooperative game theory. The present net return under non-cooperation amounts to 420,255 million won. However, if two countries cooperate one with another, this figure can get to 2,636,565 million won. We consider this to be an important conclusion as close management relationships have developed between the two countries since the establishment of the EEZ in 1996. The results of the study can also help balance resource conservation and the appropriate catch quota in each country.

위치 기반 관광 정보 서비스 보안 기술 연구 (A Study on the Security Technology of the Location based Tourism Information Service)

  • 김태경
    • 디지털산업정보학회논문지
    • /
    • 제12권2호
    • /
    • pp.25-29
    • /
    • 2016
  • Owing to the change of economic trends, the importance of the tourism industry is growing more and more. In particular, the number of foreign tourists continues to increase and the type of tourists is being changed into FIT (Foreign Independent Traveler). Therefore it is an important issue to provide the effective information to foreign tourists. To solve these problems, a variety of IT technology is being used in the tourism information systems. Especially the location based tour information service is being emerged. This kinds of tourism information service is a type of LBS (Location Based Services). But if the security of the location based tourism information service is not guaranteed, it can lead to many dangers. In this paper, the trends of location based tourism information service are surveyed. Also the security threats and countermeasures for the location based tourism information service are analyzed. This paper suggests secret considerations for the location based tourism information service.

응급의료정보시스템의 보호를 위한 보안 구조 (Security Structure for Protection of Emergency Medical Information System)

  • 신상열;양환석
    • 디지털산업정보학회논문지
    • /
    • 제8권2호
    • /
    • pp.59-65
    • /
    • 2012
  • Emergency medical information center performs role of medical direction about disease consult and pre-hospital emergency handling scheme work to people. Emergency medical information system plays a major role to be decreased mortality and disability of emergency patient by providing information of medical institution especially when emergency patient has appeared. But, various attacks as a hacking have been happened in Emergency medical information system recently. In this paper, we proposed security structure which can protect the system securely by detecting attacks from outside effectively. Intrusion detection was performed using rule based detection technique according to protocol for every packet to detect attack and intrusion was reported to control center if intrusion was detected also. Intrusion detection was performed again using decision tree for packet which intrusion detection was not done. We experimented effectiveness using attacks as TCP-SYN, UDP flooding and ICMP flooding for proposed security structure in this paper.

GPS 애플리케이션에 대한 컴포넌트 기반의 요구사항 분석 (Component-based Requirements Analysis for the GPS Applications)

  • 이상영;이윤현
    • 디지털산업정보학회논문지
    • /
    • 제8권2호
    • /
    • pp.177-188
    • /
    • 2012
  • GIS provides the various analyzing and displaying using diverse spatial data have supported the powerful functionality and friendly user-interface. But, early GIS software is developed as package tool, it have many difficulties with reducing the cost of developing GPS application and satisfying the various user requirements. At present, the developed GPS applications across multiple domains, despite the common features are built separately for each domain in terms of software engineering development followed out waste of time and money expenditure. However, common features between GPS applications, if deployed as a component assembly and reuse components in terms of enabling the two kinds of component-based development can bring out the beneficial results. In this paper, we described the Analysis and design of GPS ApplicationsS based on Component. Each GPS component is composed of many objects accomplish the atomic service processing and cooperate with each other. And, GPS components meets the qualifications of thc low cost of developing GPS application because of the reusability and re-composition.

영상의 지역성을 이용한 보간 영상의 화질 개선 기법 (Quality Improvement Scheme of Interpolated Image using the Locality)

  • 정수목
    • 디지털산업정보학회논문지
    • /
    • 제6권4호
    • /
    • pp.217-223
    • /
    • 2010
  • In the case of image magnification by using interpolation methods, interpolated pixels are estimated from the known pixels in source image. The magnified image is composed of the known pixels in source image and the interpolated pixels which is estimated. If the interpolated pixels are estimated to have the locality which is exists in real images, the magnified image is much closer to the real image. In this paper, an improved interpolation scheme is proposed to estimate pixels from the known pixels in source image using the locality which is exists in real images. The magnified image by using the proposed interpolation scheme is much closer to the real image. The performance of the proposed interpolation scheme is evaluated by using PSNR(Peak Signal to Noise Ratio) in experiment. The PSNR of the magnified image by using the proposed scheme is improved than that of the magnified images by using existing interpolation methods. So, the proposed interpolation scheme is an efficient interpolation method for the quality improvement of magnified image.