• Title/Summary/Keyword: information recovering

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Diagnosis and recovering on spatially distributed acceleration using consensus data fusion

  • Lu, Wei;Teng, Jun;Zhu, Yanhuang
    • Smart Structures and Systems
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    • v.12 no.3_4
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    • pp.271-290
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    • 2013
  • The acceleration information is significant for the structural health monitoring, which is the basic measurement to identify structural dynamic characteristics and structural vibration. The efficiency of the accelerometer is subsequently important for the structural health monitoring. In this paper, the distance measure matrix and the support level matrix are constructed firstly and the synthesized support level and the fusion method are given subsequently. Furthermore, the synthesized support level can be served as the determination for diagnosis on accelerometers, while the consensus data fusion method can be used to recover the acceleration information in frequency domain. The acceleration acquisition measurements from the accelerometers located on the real structure National Aquatics Center are used to be the basic simulation data here. By calculating two groups of accelerometers, the validation and stability of diagnosis and recovering on acceleration based on the data fusion are proofed in the paper.

A Study on the Efficiency Improvement of a 3D Shape Measuring Apparatus With High Speed (고속 3차원 형상 측정 장치의 효율성 향상에 관한 연구)

  • 박승규;이일근;이영훈
    • Journal of the Korea Society of Computer and Information
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    • v.6 no.4
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    • pp.104-109
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    • 2001
  • In this paper, we designed a 3D shape measuring system with high speed and high measurement resolution using line-shaped sine stripes of a LCD projector We proposed an effective method to improve measurement efficiency for a 3D shape measuring system by finding the deficient shape information areas and recovering the shape information efficiently. We experimentally confirmed the improvement of measurement efficiency. Deficient shape information areas can be inevitably existed in a acquired image caused by the camera view angle and surface shapes of an object. The measurement efficiency is turned out to be improved by extracting these shadow areas and recovering the shape information efficiently using both a variable rated normalization and a variable sized phase recovering windows.

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A Study on Analyzing Caption Characteristic for Recovering Original Images of Caption Region in TV Scene (원 영상 복원을 위한 TV 자막 특성 분석에 관한 연구)

  • Chun, Byung-Tae
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.4
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    • pp.177-182
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    • 2010
  • Research on recovering original images from captions has been widely done in a reusability point of view. In usual, dynamic images imported from foreign countries often have captions of foreign languages, so it is necessary to translate them into one's language. For the natural exchange of captions without loss of original images, recovering the images corresponding to captions is necessary. However, though recovering original images is very important, systematic analysis on the characteristics of captions has not been done yet. Therefore, in this paper, we first survey the classification methods of TV programs at academic worlds, broadcasting stations, and broadcasting organizations, and then analyses the frequency of captions, importance of caption contents, and necessity of recovering according to their types. Also, we analyze the characteristics of captions which are significantly recognized to be necessary to recover, and use them as recovering information.

Recovering RSA Private Key Bits from Erasures and Errors (삭제와 오류로부터 RSA 개인키를 복구하는 알고리즘)

  • Baek, Yoo-Jin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.27 no.4
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    • pp.951-959
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    • 2017
  • Under the assumption that there is available some additional information other than plaintext-ciphertext pairs, the security of the RSA cryptosystem has been analyzed by the attack methods such as the side-channel attacks and the lattice-based attacks. Recently, based on the data retention property of the powered-off DRAMs, the so called cold boot attack was proposed in the literature, which is focusing on recovering the various cryptosystems' key from some auxiliary information. This paper is dealing with the problem of recovering the RSA private key with erasures and errors and proposes a new key recovery algorithm which is shown to have better performance than the previous one introduced by Kunihiro et al.

An Efficient Recovery Algorithm based on Causal Message Logging in Distributed Systems (분산 시스템에서 인과적 메시지 로깅에 기반한 효율적 회복 알고리즘)

  • An, Jin-Ho;Jeong, Gwang-Sik;Kim, Gi-Beom;Hwang, Jong-Seon
    • Journal of KIISE:Computer Systems and Theory
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    • v.26 no.10
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    • pp.1194-1205
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    • 1999
  • 인과적 메시지 로깅은 정상수행시 낙관적 메시지 로깅의 장점을 가지고, 회복시 비관적 메시지 로깅의 장점을 가지고 있다. 본 논문에서는 회복 프로세스들간의 비동기성을 향상시키기 위한 인과적 메시지 로깅에 기반한 새로운 회복 알고리즘을 제안하고자 한다. 기존의 인과적 메시지 로깅 기반 회복 알고리즘들은 살아있는 프로세스들의 수행을 대기시키거나, 회복 프로세스들간의 높은 동기성을 요구한다. 본 논문에서 제안하는 회복 알고리즘은 각 회복 프로세스가 자신의 회복만을 책임지게 함으로써, 여러 개의 프로세스들이 동시적으로 고장이 발생하더라도 회복시 살아있는 프로세스들의 수행을 대기시키지 않고, 회복 프로세스들 중 하나의 회복 프로세스에게만 과부하가 발생하지 않도록 한다. 또한, 제안하는 알고리즘은 각 회복 프로세스의 회복 과정이 다른 회복 프로세스의 연속적인 고장들에 의해 지연되지 않도록 한다. 본 논문에서는 제안하는 회복 알고리즘의 정당성을 증명하고, 시뮬레이션을 통해서 제안하는 회복 알고리즘이 기존 회복 알고리즘에 비해 고장난 프로세스의 평균회복시간을 단축시킨다는 것을 보여준다.Abstract Causal message logging has the advantages of optimistic message logging during failure-free execution and pessimistic message logging during recovery. In this paper, we present a new recovery algorithm based on causal message logging for improving asynchrony among recovering processes. Existing recovery algorithms based on causal message logging block the execution of live processes or require high synchronization among recovering processes. As each recovering process is responsible for only its recovery in our algorithm, the algorithm avoids blocking the execution of live processes during recovery even in concurrently multiple failures and overloading only one among recovering processes. Moreover, it allows the recovery of each recovering process not to be delayed by the continuous failures of other recovering processes. We prove the correctness of our recovery algorithm, and our simulation results show that our algorithm reduces the average recovery time of a failed process compared with the existing recovery algorithms.

On Recovering Erased RSA Private Key Bits

  • Baek, Yoo-Jin
    • International Journal of Internet, Broadcasting and Communication
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    • v.10 no.3
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    • pp.11-25
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    • 2018
  • While being believed that decrypting any RSA ciphertext is as hard as factorizing the RSA modulus, it was also shown that, if additional information is available, breaking the RSA cryptosystem may be much easier than factoring. For example, Coppersmith showed that, given the 1/2 fraction of the least or the most significant bits of one of two RSA primes, one can factorize the RSA modulus very efficiently, using the lattice-based technique. More recently, introducing the so called cold boot attack, Halderman et al. showed that one can recover cryptographic keys from a decayed DRAM image. And, following up this result, Heninger and Shacham presented a polynomial-time attack which, given 0.27-fraction of the RSA private key of the form (p, q, d, $d_p$, $d_q$), can recover the whole key, provided that the given bits are uniformly distributed. And, based on the work of Heninger and Shacham, this paper presents a different approach for recovering RSA private key bits from decayed key information, under the assumption that some random portion of the private key bits is known. More precisely, we present the algorithm of recovering RSA private key bits from erased key material and elaborate the formula of describing the number of partially-recovered RSA private key candidates in terms of the given erasure rate. Then, the result is justified by some extensive experiments.

Recovering the Original Form of Ancient Relics'Letters Using Z-map and Morphological Filters (Z-map과 모폴로지 필터를 이용한 문화재 문자 복원)

  • Moon, Ho-Seok;Sohn, Myung-Ho
    • KSCI Review
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    • v.14 no.2
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    • pp.141-146
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    • 2006
  • In this paper, we propose a new algorithm for recovering the broken letters of relics into an original form by using Z-map and image processing. The letters of relics may have been broken by a lot of rubbed copy and a long time and tide. They need to be restored. But the manual reconstruction is a very tedious and laborious task. Thus, it is necessary to automate the restoration process. This paper presents a realistic algorithm with an application to Tripitaka Koreana by using Z-map and morphological filter.

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Developing Expert System for Restoration to the Original Character Form of Ancient Relics Based on Image Processing and Computer Graphics (문화재의 문자 복원을 위한 전문가 시스템 개발: 영상처리 및 컴퓨터 그래픽스 활용을 중심으로)

  • Moon, Ho-Seok;Sohn, Myung-Ho
    • Journal of Information Technology Services
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    • v.7 no.4
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    • pp.139-149
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    • 2008
  • We propose expert system for restoration the original character form of ancient relics based on image processing and computer graphics. Letters engraved in relief like relics and intaglio like curved tombstones and letters engraved in plane or curved part of cultural asset may have been broken by a lot of rubbed copy, a long time and tide. In this paper, we suggest a new method for extracting and recovering the broken letters of cultural asset into an original form by using Z-map, morphological filter, and high frequency filter. Based on the suggested method. we develop the character recovering system.

The Implementation of Kernel Hardening Function by Recovering the Stack Frame of Malfunction Address on the Linux Operating System (리눅스 운영체제에서 주소값 오류시 스택 복구를 통한 커널 하드닝 기능 구현)

  • Jang, Seung-Ju
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.1
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    • pp.173-180
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    • 2007
  • This paper designs the kernel hardening function by recovering the kernel stack fame to reduce the system error or panic due to the kernel code error. The suggested kernel hardening function guarantees normal system operation by recovering the incorrect address of the kernel stack kernel. The suggesting kernel hardening mechanism is applied to the network module of Linux which is much using put. I experimented the kernel hardening function at the network module of the Linux by forcing panic code.