• 제목/요약/키워드: Key size

검색결과 1,797건 처리시간 0.03초

동역학계를 이용한 난수열 발생 시스템 (Pseudo-random bit sequence generator based on dynamical systems)

  • 김재겸;조성진;김한두;이경현;손호준
    • 한국멀티미디어학회논문지
    • /
    • 제4권2호
    • /
    • pp.182-188
    • /
    • 2001
  • 본 논문에서는 동역학계를 해석하는 방법들 중의 한가지인 다차원 셀룰라 오토마타에 기초한 난수열 발생 시스템을 제안하였다. 제안된 난수열 발생 시스템은 키의 사용이 요구되는 경우와 요구되지 않는 경우에 모두 적용이 가능하도록 구성되었으며, 키를 사용하는 경우 키의 크기는 128bits에서 256bits까지 가변적으로 사용할 수 있게 구성되었다. 제안된 난수열 발생 시스템의 수행속도는 Pentium MMX 200MHz (64M RAM, Windows 98) 환경에서 약 280Mbits/sec로 측정되었다.

  • PDF

CELM 암호화 알고리즘의 성능 비교 (Performance Comparison of the CELM Encryption Algorithm)

  • 박혜련;이종혁
    • 한국정보통신학회논문지
    • /
    • 제6권3호
    • /
    • pp.481-486
    • /
    • 2002
  • 본 논문에서는 카오스에 기반을 툰 ELM(Expanding Logistic Map) 암호화 알고리즘을 개선하기 위해 CELM(Cascade ELM)을 제안한다. 제안된 암호화 알고리즘은 3차 방정식에 기반을 둔 ELM 의 차수를 증가시켜 키의 범위를 확대하고, 서로 다른 Key 값과 초기 값의 함수를 Cascade 연결한 것으로 시뮬레이션결과 키의 랜덤성이 보장되면서 안정성이 국제 기준에 부합됨을 알 수 있었다.

국내 중소기업의 전략유형과 특성;제조업을 중심으로 (Strategic typologies of Korean SMEs in manufacturing industries)

  • 이병헌;박상문;손병호;장지호
    • 한국벤처창업학회:학술대회논문집
    • /
    • 한국벤처창업학회 2006년 춘계학술발표회
    • /
    • pp.139-166
    • /
    • 2006
  • This paper explored strategic types of Korean SMEs in manufacturing industries and investigated key differences among strategic types by analysing firm size, product market, technological capabilities and performances. According to previous studies, this papers categorized SMEs into four strategic types-technological innovative SMEs, multi-product SMEs, capital-intensive SMEs, and OEM-based SMEs types. Based on the empirical survey from 1,077 Korea SMEs in diverse industries, there are significant differences among strategic types on the key characteristics including product market, resource capability and performance. Finally this paper suggested implications for the studies on SMEs and managerial and policy directions to support SMEs.

  • PDF

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.

전문도서관의 마케팅전략 (On the marketing strategies of special libraries)

  • 최상기
    • 한국도서관정보학회지
    • /
    • 제23권
    • /
    • pp.147-182
    • /
    • 1995
  • Marketing technique is used as effective management tool in library. The small size of the user group in special libraries provides good condition for marketing. Special libraries can accomplish the goals and objectives with using marketing technique. The purpose of this study is to examine key concepts and activity procedures of marketing, and marketing mix 4'P, and to suggest the information services which can be used in developing marketing strategies of special libraries. The conclusions are summarized as follows. 1. The key concepts and activity procedure of marketing for libraries consist of market segmentation, positioning, consumer analysis, marketing program and marketing audit. 2. The marketing mix 4P's that can be used in special libraries are examined. 3. The information services which can be used in marketing strategies are suggested.

  • PDF

문서지문기법을 이용한 웹 문서의 자동 분류

  • 김진화
    • 한국경영과학회:학술대회논문집
    • /
    • 한국경영과학회 2004년도 추계학술대회 및 정기총회
    • /
    • pp.407-429
    • /
    • 2004
  • As documents in webs are increasing explosively due to the rapid development of electronic documents, an efficient system classifying documents automatically is required. In this study, a new document classification method, which is called Document Finger Print Method, is suggested to classify web documents automatically and efficiently. The performance of the suggested method is evaluated alone with other existing methods such as key words based method, weighted key words based method, neural networks, and decision trees. An experiment is designed with 10 documents categories and 59 randomly selected words. The result shows that the suggested algorithm has a superior classifying performance compared to other methods. The most important advantage of this method is that the suggested method works well without the size limits of the number of words in documents.

  • PDF

GOST 암호화 알고리즘의 구현 및 분석 (Design and Analysis of the GOST Encryption Algorithm)

  • 류승석;정연모
    • 한국시뮬레이션학회논문지
    • /
    • 제9권2호
    • /
    • pp.15-25
    • /
    • 2000
  • Since data security problems are very important in the information age, cryptographic algorithms for encryption and decryption have been studied for a long time. The GOST(Gosudarstvennyi Standard or Government Standard) algorithm as a data encryption algorithm with a 256-bit key is a 64-bit block algorithm developed in the former Soviet Union. In this paper, we describe how to design an encryption chip based on the GOST algorithm. In addition, the GOST algorithm is compared with the DES(Data Encryption Standard) algorithm, which has been used as a conventional data encryption algorithm, in modeling techniques and their performance. The GOST algorithm whose key size is relatively longer than that of the DES algorithm has been expanded to get better performance, modeled in VHDL, and simulated for implementation with an CPLD chip.

  • PDF

사용자 만족도를 고려한 터치 버튼 사이즈에 대한 연구 (A User Satisfaction Based Touch Button Design)

  • 김진;최광수
    • 산업공학
    • /
    • 제20권4호
    • /
    • pp.539-546
    • /
    • 2007
  • This study has been conducted on touch screen interface design for mobile devices. It was intended to measure user’s satisfaction on one-handed thumb input mobile devices. Recent studies proposed the optimal touch button size, but it is inappropriate for mobile devices. Therefore, this study was focused on four touch key factors-width, height, the horizontal and vertical distance between touch keys-as independent variables. The ANOVA results showed that the user satisfaction of four touch key factors was significantly affected by the thumb input. It also apparent that the interactions between four factors were significant. As a result, the horizontal and vertical distance as well as the width and height affected the satisfaction of users. In addition, this study suggested satisfaction models which represent the top 30%, 50%, 70% of user satisfaction measurement. The results of this study could be used to design touch keys that are able to enhance the usability on touch screen based mobile devices.

Novel Quasi-Elliptic Function Bandpass Filter Using Hexagonal Resonators with Capacitive Loading

  • Wang, Changtao;Li, Wenming;Liu, Feng;Liu, Haiwen
    • ETRI Journal
    • /
    • 제30권4호
    • /
    • pp.615-617
    • /
    • 2008
  • A novel and compact elliptic-function bandpass filter is proposed in this letter. The techniques of slot etching and the addition of open stubs are applied to enhance the self-inductance and self-capacitance of hexagonal open-loop resonators. Thus, size reduction and improved transmission performance are obtained. Compared to the performance of the conventional design, the central frequency and insertion loss are reduced by 28% and 3.1 dB, respectively. Measurements show that the proposed filter has a fraction bandwidth of 23% at the central frequency of 1.84 GHz, and its insertion loss in the passband is less than -1.5 dB. The bandpass filter occupies only 12 mm${\times}$21.2 mm (approximately $0.24{\lambda}_g{\times}0.14{\lambda}_g$).

  • PDF

Lucifer 형태의 암호화 알고리듬에 관한 연구 (A Study on Lucifer-Type Encryption Algorithm)

  • 강해동;이창순;문상재
    • 대한전자공학회논문지
    • /
    • 제26권3호
    • /
    • pp.32-39
    • /
    • 1989
  • 본 논문에서는 Lucifer의 카이바이트 사용스케줄과 펼쳐진 콘볼루션 레지스터를 변화시키면서 32, 64, 그리고 256비트 블록크기 Lucifer형태의 암호화 알고리듬을 제시하고 이들의 심볼간 상호의존도와 exhaustive 암호 분석의 비도를 비교 조사한다. 또 키이 interruption 위치 변경과 autoclave방식의 대체상자 입력 등의 심볼간 상호의존도를 개선하는 방법들도 제시한다.

  • PDF