• Title/Summary/Keyword: 블록 기반 방법

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A Model for Self-Authentication Based on Decentralized Identifier (탈중앙화 신원증명에 기반한 본인 인증 모델)

  • Kim, Ho-Yoon;Han, Kun-Hee;Shin, Seung-Soo
    • Journal of Convergence for Information Technology
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    • v.11 no.11
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    • pp.66-74
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    • 2021
  • With the development of the Internet, user authentication technology that proves me online is improving. Existing ID methods pose a threat of personal information leakage if the service provider manages personal information and security is weak, and the information subject is to the service provider. In this study, as online identification technology develops, we propose a DID-based self-authentication model to prevent the threat of leakage of personal information from a centralized format and strengthen sovereignty. The proposed model allows users to directly manage personal information and strengthen their sovereignty over information topics through VC issued by the issuing agency. As a research method, a self-authentication model that guarantees security and integrity is presented using a decentralized identifier method based on distributed ledger technology, and the security of the attack method is analyzed. Because it authenticates through DID Auth using public key encryption algorithms, it is safe from sniffing, man in the middle attack, and the proposed model can replace real identity card.

Efficient Coding of Motion Vector Predictor using Phased-in Code (Phased-in 코드를 이용한 움직임 벡터 예측기의 효율적인 부호화 방법)

  • Moon, Ji-Hee;Choi, Jung-Ah;Ho, Yo-Sung
    • Journal of Broadcast Engineering
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    • v.15 no.3
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    • pp.426-433
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    • 2010
  • The H.264/AVC video coding standard performs inter prediction using variable block sizes to improve coding efficiency. Since we predict not only the motion of homogeneous regions but also the motion of non-homogeneous regions accurately using variable block sizes, we can reduce residual information effectively. However, each motion vector should be transmitted to the decoder. In low bit rate environments, motion vector information takes approximately 40% of the total bitstream. Thus, motion vector competition was proposed to reduce the amount of motion vector information. Since the size of the motion vector difference is reduced by motion vector competition, it requires only a small number of bits for motion vector information. However, we need to send the corresponding index of the best motion vector predictor for decoding. In this paper, we propose a new codeword table based on the phased-in code to encode the index of motion vector predictor efficiently. Experimental results show that the proposed algorithm reduces the average bit rate by 7.24% for similar PSNR values, and it improves the average image quality by 0.36dB at similar bit rates.

An Efficient Post-Quantum Signature Scheme Based on Multivariate-Quadratic Equations with Shorter Secret Keys (양자컴퓨터에 안전한 짧은 비밀키를 갖는 효율적인 다변수 이차식 기반 전자서명 알고리즘 설계)

  • Kyung-Ah Shim
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.2
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    • pp.211-222
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    • 2023
  • Multivariate quadratic equations (MQ)-based public-key cryptographic algorithms are one of promising post-quantumreplacements for currently used public-key cryptography. After selecting to NIST Post-Quantum Cryptography StandardizationRound 3 as one of digital signature finalists, Rainbow was cryptanalyzed by advanced algebraic attacks due to its multiple layered structure. The researches on MQ-based schemes are focusing on UOV with a single layer. In this paper, we propose a new MQ-signature scheme based on UOV using the combinations of the special structure of linear equations, spare polynomials and random polynomials to reduce the secret key size. Our scheme uses the block inversion method using half-sized blockmatrices to improve signing performance. We then provide security analysis, suggest secure parameters at three security levels and investigate their key sizes and signature sizes. Our scheme has the shortest signature length among post-quantumsignature schemes based on other hard problems and its secret key size is reduced by up to 97% compared to UOV.

Efficient Exploration of On-chip Bus Architectures and Memory Allocation (온 칩 버스 구조와 메모리 할당에 대한 효율적인 설계 공간 탐색)

  • Kim Sungcham;Im Chaeseok;Ha Soonhoi
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.2
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    • pp.55-67
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    • 2005
  • Separation between computation and communication in system design allows the system designer to explore the communication architecture independently of component selection and mapping. In this paper we present an iterative two-step exploration methodology for bus-based on-chip communication architecture and memory allocation, assuming that memory traces from the processing elements are given from the mapping stage. The proposed method uses a static performance estimation technique to reduce the large design space drastically and quickly, and applies a trace-driven simulation technique to the reduced set of design candidates for accurate Performance estimation. Since local memory traffics as well as shared memory traffics are involved in bus contention, memory allocation is considered as an important axis of the design space in our technique. The viability and efficiency of the proposed methodology arc validated by two real -life examples, 4-channel digital video recorder (DVR) and an equalizer for OFDM DVB-T receiver.

A Method for Reliability Analysis of Armored Fighting Vehicle using RBD based on Integrated Hit Probabilities of Crews and Components (통합 피격 확률 분석을 이용한 RBD 기반의 전차 신뢰도 분석 방법)

  • Hwang, Hun-Gyu;Kang, Ji-Won;Lee, Jang-Se
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.5
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    • pp.1040-1048
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    • 2016
  • Recently, the studies of integrated reliability analysis for combat systems are actively progressing. Especially, the research of integrated reliability analysis is emphasized to overcome limitations of the previous studies. In this paper, we propose a calculation technique for integrated hit probability based on front and side hit probabilities that analyzed in previous studies to improve the time-effectiveness. Also, we find out the integrated reliability of each component based on the integrated hit probability which is calculated, and we propose the method which applied the reliability block diagram technique to analyze the whole combat system of the reliability by function kills. For verifying the proposed method, we applied the proposed method to armored fighting vehicle model. The proposed method considers crew which does not considered the element in the previous study and expects to enhance the accuracy of reliability analysis and the time-effectiveness compared with the previous study.

A Study for a real-time variety region(object) extraction algorithm to implement MPEG-4 based Video Phones. (MPEG-4 기반의 영상전화기 구현을 위한 실시간 변환영역(객체) 추출에 관한 알고리즘)

  • Oh, In-Gwon;Shon, Young-Woo;Namgung, Jae-Chan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.1C
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    • pp.92-101
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    • 2004
  • This paper proposes a algorithm to extract the variety region (object) from video for the real-time encoding of MPEG-4 based. The previous object segmentation methods cannot used the videophone or videoconference required by real-time processing. It is difficult to transfer a video to real-time because it increased complexity for the operation of each pixel on the spatial segmentation and temporal segmentation method proposed by MPEG-4 Working Group. But algorithm proposed for this thesis not operates a pixel unit but operates a macro block unit. Thus this enables real-time transfer. But this algorithm cannot extract several object for a image using proposed algorithm as previous algorithm. On system constructed by encoder and decoder. A proposed algorithm inserted for encoder as pre-process.

The Content-Based Image Retrieval by using Color Histogram and Shape-Based Feature Extraction (컬러 히스토그램과 형상 기반 특징 추출을 이용한 내용 기반 영상 검색)

  • Kang, Hyun-Inn;Ju, Yong-Wan;Baek, Kwang-Ryul
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.10
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    • pp.113-122
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    • 1999
  • When we want to retrieve the most similar image from the image database, the color histogram intersection, shape feature and texture feature comparing method are used as a metric to measure the similarity. In order to increase the accuracy of retrievals, we need to integrate two different features. In this paper, the histogram intersection and shape based block histogram intersection method are used. This method results in a high efficient algorithm that meets a similar accuracy and a relatively fast retrieval speed compared to the method of integration of two different features. The Proposed algorithm is tested on retrievals of image database consisting of various 600 images and we implemented that the proposed algorithm gives fast, high efficiency and reliability compared to others.

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An Accurate Moving Distance Measurement Using the Rear-View Images in Parking Assistant Systems (후방영상 기반 주차 보조 시스템에서 정밀 이동거리 추출 기법)

  • Kim, Ho-Young;Lee, Seong-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.12
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    • pp.1271-1280
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    • 2012
  • In the recent parking assistant systems, finding out the distance to the object behind a car is often performed by the range sensors such as ultrasonic sensors, radars. However, the installation of additional sensors on the used vehicle could be difficult and require extra cost. On the other hand, the motion stereo technique that extracts distance information using only an image sensor was also proposed. However, In the stereo rectification step, the motion stereo requires good features and exacts matching result. In this paper, we propose a fast algorithm that extracts the accurate distance information for the parallel parking situation using the consecutive images that is acquired by a rear-view camera. The proposed algorithm uses the quadrangle transform of the image, the horizontal line integral projection, and the blocking-based correlation measurement. In the experiment with the magna parallel test sequence, the result shows that the line-accurate distance measurement with the image sequence from the rear-view camera is possible.

Change Detection Algorithm based on Positive and Negative Selection of Developing T-cell (T세포 발생과정의 긍정 및 부정 선택에 기반한 변경 검사 알고리즘)

  • Sim, Kwee-Bo;Lee, Dong-Wook
    • Journal of the Korean Institute of Intelligent Systems
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    • v.13 no.1
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    • pp.119-124
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    • 2003
  • In this paper, we modeled positive selection and negative selection that is developing process of cytotoxic T-cell that plays important role in biological immune system. Also, we developed change detection algorithm, which is very Important part in detecting data change by intrusion and data infection by computer virus. Proposed method is the algorithm that produces MHC receptor lot recognizing self and antigen detector for recognizing non-self. Therefore, proposed method detects self and intruder by two type of detectors like real immune system. We show the effectiveness and characteristics of proposed change detection algorithm by simulation about point and block change of self file.

A Position-Based Block Similarity Computing Method for Similar Transcript Model Search (유사 전사체 모델 탐색을 위한 위치 기반 블록 간의 유사도 비교 기법)

  • Kim, Sora;Park, TaeWon;Hwang, HyeRyeon;Cho, Hwan-Gue
    • Proceedings of the Korea Information Processing Society Conference
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    • 2012.11a
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    • pp.1326-1329
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    • 2012
  • 전사체(transcript)는 유전자로부터 전사된 DNA 시퀀스 코드를 말한다. 전사체(transcript)의 발현된 형태에 따라 생성되는 단백질의 형태 역시 달라지므로 전사체 모델의 형태는 중요한 의미를 가지며 특정 위치의 전사체가 정상과 다르게 모델이 변할 경우 심각한 경우에는 유전자 질병에 노출될 수 있다. 현재 실험체에 대한 전사체 모형은 SpliceGrapher, Cufflinks와 같은 상용화된 도구들을 사용하여 얻을 수 있다. 하지만 이런 도구 간의 결과 값 및 어노테이션 정보와 결과 값 간의 유사도 비교를 위한 방법론은 현재 알려진 바 없다. 대신 전사체 비교를 위해 모형 간의 차이를 눈으로 하나씩 비교하거나 전사체 위치를 이용한 산수 값을 이용한다. 본 논문에서는 전사체 모형 간의 유사도를 비교하기 위한 방법론을 제시하고 Homo sapiens grch37 어노테이션 파일과 SRR387514 실험 데이터 간의 유사도를 제시한 방법론을 이용하여 측정한 결과 값을 분석하였다.