• Title/Summary/Keyword: binary codes

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An Anti-Forensic Technique for Hiding Data in NTFS Index Record with a Unicode Transformation (유니코드 변환이 적용된 NTFS 인덱스 레코드에 데이터를 숨기기 위한 안티포렌식 기법)

  • Cho, Gyu-Sang
    • Convergence Security Journal
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    • v.15 no.7
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    • pp.75-84
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    • 2015
  • In an "NTFS Index Record Data Hiding" method messages are hidden by using file names. Windows NTFS file naming convention has some forbidden ASCII characters for a file name. When inputting Hangul with the Roman alphabet, if the forbidden characters for the file name and binary data are used, the codes are convert to a designated unicode point to avoid a file creation error due to unsuitable characters. In this paper, the problem of a file creation error due to non-admittable characters for the file name is fixed, which is used in the index record data hiding method. Using Hangul with Roman alphabet the characters cause a file creation error are converted to an arbitrary unicode point except Hangul and Roman alphabet area. When it comes to binary data, all 256 codes are converted to designated unicode area except an extended unicode(surrogate pairs) and ASCII code area. The results of the two cases, i.e. the Hangul with Roman alphabet case and the binary case, show the applicability of the proposed method.

Static Control Flow Analysis of Binary Codes (이진 코드의 정적 제어 흐름 분석)

  • Kim, Ki-Tae;Kim, Je-Min;Yoo, Weon-Hee
    • The Journal of the Korea Contents Association
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    • v.10 no.5
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    • pp.70-79
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    • 2010
  • We perform static program analysis for the binary code. The reason you want to analyze at the level of binary code, installed on your local computer, run the executable file without source code. And the reason we want to perform static analysis, static program analysis is to understand what actions to perform on your local computer. In this paper, execution flow graph representing information such as the execution order among functions and the flow of control is generated. Using graph, User can find execution flow of binary file and calls of insecure functions at the same time, and the graph should facilitate the analysis of binary files. In addition, program to be run is ensured the safety by providing an automated way to search the flow of execution, and program to be downloaded and installed from outside is determined whether safe before running.

Improvement of Flexible Zerotree Coder by Efficient Transmission of Wavelet Coefficients (웨이블렛 계수의 효율적인 전송에 따른 가변제로트리코더의 성능개선)

  • Joo, Sang-Hyun;Shin, Jae-Ho
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.9
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    • pp.76-84
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    • 1999
  • EZW proposed by Shapiro is based on a zerotree constructed in a way that a parent coefficient in a subband is related to four child coefficients in the next finer subband of similar orientation. This fixed treeing based on 1-to-4 parent-child is suitable to exploti hierachical correlations among subbands but not to exploit spatial correlations within a subband. A new treeing by Joo, et al. is suggested to simulatneously exploit those two correlatins by extending parent-child relationship in a flexible way. The flexible treeing leads to increasing the number of symbols and lowering entorpy comparing to the fixed treeing, and therefore a better compression can be resulted. In this paper, we suggest two techniques to suppress the increasing of symbols. First, a probing bit is generated to avoid redundant scan for insignivicant coefficients. Second, since all subbands do not always require the same kind of symbol-set, produced symbols are re-symbolized into binary codes according to a pre-defined procedure. Owing to those techniques, all symbols are generated as binary codes. The binary symbols can be entropy-coded by an adaptive arithmetic coding. Moerover, the binary symbol stream can give comparatively good performances without help of additional entropy coding. Our proposed coding scheme is suggested in two modes: binary coding mode and arithmetic coding mode. We evaluate the effectivenessof our modifications by comparing with the original EZW.

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A Passport Recognition and face Verification Using Enhanced fuzzy ART Based RBF Network and PCA Algorithm (개선된 퍼지 ART 기반 RBF 네트워크와 PCA 알고리즘을 이용한 여권 인식 및 얼굴 인증)

  • Kim Kwang-Baek
    • Journal of Intelligence and Information Systems
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    • v.12 no.1
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    • pp.17-31
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    • 2006
  • In this paper, passport recognition and face verification methods which can automatically recognize passport codes and discriminate forgery passports to improve efficiency and systematic control of immigration management are proposed. Adjusting the slant is very important for recognition of characters and face verification since slanted passport images can bring various unwanted effects to the recognition of individual codes and faces. Therefore, after smearing the passport image, the longest extracted string of characters is selected. The angle adjustment can be conducted by using the slant of the straight and horizontal line that connects the center of thickness between left and right parts of the string. Extracting passport codes is done by Sobel operator, horizontal smearing, and 8-neighborhood contour tracking algorithm. The string of codes can be transformed into binary format by applying repeating binary method to the area of the extracted passport code strings. The string codes are restored by applying CDM mask to the binary string area and individual codes are extracted by 8-neighborhood contour tracking algerian. The proposed RBF network is applied to the middle layer of RBF network by using the fuzzy logic connection operator and proposing the enhanced fuzzy ART algorithm that dynamically controls the vigilance parameter. The face is authenticated by measuring the similarity between the feature vector of the facial image from the passport and feature vector of the facial image from the database that is constructed with PCA algorithm. After several tests using a forged passport and the passport with slanted images, the proposed method was proven to be effective in recognizing passport codes and verifying facial images.

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CODES BASED ON RESIDUATED LATTICES

  • Atamewoue, Tsafack Surdive;Jun, Young Bae;Lele, Celestin;Ndjeya, Selestin;Song, Seok-Zun
    • Communications of the Korean Mathematical Society
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    • v.31 no.1
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    • pp.27-40
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    • 2016
  • We define the notion of a residuated lattice valued function on a set as Jun and Song have done in BCK-algebras. We also investigate related properties of residuated lattice valued function. We establish the codes generated by residuated lattice valued function and conversely we give residuated lattice valued function and residuated lattice obtained by the giving binary block-code.

An algorithm in Davis method for assigning input codes (Input code를 지정하기 위한 Davis방법의 산법)

  • 양흥석;방승양
    • 전기의세계
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    • v.18 no.3
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    • pp.15-23
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    • 1969
  • A combinational circuit is one of the fundamental elements in digital circuits, containing electronic computers. W.A. Davis presented a new approach to the problem of assigning binary input codes so that the combinational circuits necessary to realize the given output functions may be minimized. This paper has derived an algorithm for determining the actual cost of a given assignment scheme in Davis method. First, the combinations of partitions realizing the output functions are obtained and then those among them implementing all of the output functions are found by using a table. In consequence it has been proved that by this algorithm the process of the assignment in a schcme with 16 states and 3 determined partitions can be reduced to 1/10$^{6}$ .

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CONSTRUCTION OF RECURSIVE FORMULAS GENERATING POWER MOMENTS OF KLOOSTERMAN SUMS: O+(2n, 2r) CASE

  • Kim, Dae San
    • Journal of the Korean Mathematical Society
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    • v.57 no.3
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    • pp.585-602
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    • 2020
  • In this paper, we construct four infinite families of binary linear codes associated with double cosets with respect to a certain maximal parabolic subgroup of the orthogonal group O+(2n, 2r). And we obtain two infinite families of recursive formulas for the power moments of Kloosterman sums and those of 2-dimensional Kloosterman sums in terms of the frequencies of weights in the codes. This is done via Pless' power moment identity and by utilizing the explicit expressions of exponential sums over those double cosets related to the evaluations of "Gauss sums" for the orthogonal groups O+(2n, 2r).

Pulse Code Signal Recognition using Integra-Normalizer (인테그라-노말라이저를 이용한 펄스코드 신호인식)

  • Kim, Seong-Su
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.8
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    • pp.491-494
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    • 2000
  • A scheme is proposed for measuring similarities between the binary pulse signals in the pulse-code modulation using the Integra-Normalizer. The Integra-Normalizer provides a better interpretation of the relationship between the pulse signals by removing redundant codes, which maps all possible observed signals to one of the codes to be received with relative similarities between each pair of compared signals. The proposed method provides better error tolerance than L2 metric, such as Hamming distance, since the distances between pulse signals are measured not useful for the time-delay detection in the pulse-code modulation.

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M-ary orthogonal CDMA Using Time Hopping Codes (시간도약부호를 사용하는 M진직교 부호분할 다원접속)

  • 김일규;김동인;노종선
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.7
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    • pp.1374-1389
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    • 1994
  • In this paper, a novel M-ary orthogonal CDMA scheme which utilizes time hopping codes and binary orthogonal sequences is proposed for personal communication system. Its modulated output signal has the characteristics of greater bandwidth occupancy and lower spectral density level as well. So this scheme is useful for spectrum overlay with existing narrowband communication systems which occupy current radio frequency channels. This paper investigates system characteristics through the analysis of modulated output signal power spectrum, and demonstrates the possibility of spectrum overlay.

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Complete Weight Enumerator of the Delsarte-Goethals Code over $Z_4$ ($Z_4$상에서 정의된 Delsarte-Goethals 부호의 완전 무게 분포)

  • 신동준
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.8C
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    • pp.765-770
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    • 2003
  • In this paper, the complete weight enumerator of the Delsarte-Goethals code over Z$_4$ is obtained. This code is divided into 3 cases and the complete weight enumerator of each case is calculated. During this weight enumeration, the blown distribution of exponential sums and binary weight distribution of the sub-codes are used. By combining this result and MacWilliams identity, the complete weight enumerator of the Goethals code over Z$_4$can be easily obtained. This result is also used for finding 3-designs from the Goethals and Delsarte-Goethals codes over Z$_4$.