• Title/Summary/Keyword: 최대공약수

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The κ-Fermat's Integer Factorization Algorithm (κ-페르마 소인수분해 알고리즘)

  • Choi, Myeong-Bok;Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.4
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    • pp.157-164
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    • 2011
  • It is very difficult problem to factorize composite number. Integer factorization algorithms, for the most part, find ($a,b$) that is congruence of squares ($a^2{\equiv}b^2$(mode $n$)) with using factoring(factor base, B) and get the result, $p=GCD(a-b,n)$, $q=GCD(a+b,n)$ with taking the greatest common divisor of Euclid based on the formula $a^2-b^2=(a-b)(a+b)$. The efficiency of these algorithms hangs on finding ($a,b$). Fermat's algorithm that is base of congruence of squares finds $a^2-b^2=n$. This paper proposes the method to find $a^2-b^2=kn$, ($k=1,2,{\cdots}$). It is supposed $b_1$=0 or 5 to be surely, and b is a double number. First, the proposed method decides $k$ by getting kn that satisfies $b_1=0$ and $b_1=5$ about $n_2n_1$. Second, it decides $a_2a_1$ that satisfies $a^2-b^2=kn$. Third, it figures out ($a,b$) from $a^2-b^2=kn$ about $a_2a_1$ as deciding $\sqrt{kn}$ < $a$ < $\sqrt{(k+1)n}$ that is in $kn$ < $a^2$ < $(k+1)n$. The proposed algorithm is much more effective in comparison with the conventional Fermat algorithm.

The Role of Applied Nutritionist (영양과 지역사회 개발 - 2. 영양지도원(營養指導員)의 역할(役割) -)

  • Chun, Sung-Kyu
    • Journal of Nutrition and Health
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    • v.9 no.4
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    • pp.4-8
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    • 1976
  • 영양지도원(營養指導員)은 자신(自身)이 알고 있는 기술(技術)을 다른 사람에게 전달(傳達)하여 그 사람으로 하여금 지도원(指導員)이 원하는 방향(方向)으로 행동(行動)을 하도록 해야 한다. 따라서 다른 사람을 지도(指導)하려면은 우선 지도원 자신(指導員自身)의 우수한 자질(資質)"이 필요(必要) 하며 이를 위(爲)하여 기술자(技術者)로서의 연마(硏磨)와 겸(兼)하여 인간(人間)의 지도자(指導者)로서의 수양(修養)을 쌓아야 한다. 그리하여 영양개선(營養改善) 의 선도적(先導的) 점화자(點火者)로 "뒤에서 계속 미는" 지원자(支援者)로서의 역할(役割)을 수행(遂行)하여야 한다. (1) 현직능별(現職能別) 영양지도원(營養指導員)의 범위(範圍)를 보건소(保健所)의 보건지도원(保健指導員), 농촌지도소(農村指導所)의 생활지도요원(生活指導要員), 군면(郡面)의 행정지도요원(行政指導要員), 농협(農協)의 부여지도요원(婦女指導要員), 의료계(醫療界)의 의사(醫師), 간호원(看護員), 조산원(助産員), 학교(學校) 교육기관(敎育機關)의 교사(敎師), 영양사(營養士), 영리회사(營利會社)의 사원(社員) 등을 들 수 있다. (2) 지도대상(指導對象)과 그 장소(場所)는 공장(工場), 학교(學校), 훈련장(訓練場), 병원(病院), 복지시설(福祉施設)과 공동취사(共同炊事) 재해시등(災害時等)의 집단급식장(集團給食場)과 이를 이용(利用)하는 對象者(대상자) 도시(都市) 농촌(農村)의 일반가정(一般家庭)의 주민(住民), 그리고 교실(敎室)에서 학교교과목(學校敎科目)을 통(通)한 학생(學生)의 학습(學習) 새마을운동(運動) 공보시설(公報施設)을 통(通)하여 대중(大衆)에게 "지도(指導)를 지도원(指導員)이" 전개(展開)할 수 있다. (3) 지도방법(指導方法)은 일반적(一般的) 학교교육과정(學校敎育過程)의 교육방법(敎育方法)을 적용(適用)하되 교외교육(校外敎育)이라는 점(點)을 잊어서는 안된다. 현실적(現實的)으로 이론(理論)과 경험(經驗)을 병행활용(倂行活用)하며 영양학(營養學)의 연구결과(硏究結果)가 반드시 또 는 곧 가정생활(家庭生活) 개인생활(個人生活)에 적응(適應)되는 것이 아니며, 행동화(行動化)되지 않는 지식(知識)과 기술(技術)은 무용(無用)하게 되므로 "다고 말 할 수 있다. 따라서 영양개선(營養改善)을 지도(指導)하는 지도원(指導員)은 받아들이는 가정(家庭)이나 개인(個人)의 입장(立場)에서 여러 가지 여건을 파악 최대공약수(最大公約數)의 가능치(可能値)를 알아내서 지도(指導)해야 된다. (4) 영양지도(營養指導)는 기술(技術)이 ,포함(包含)되어 있기 때문에 기술(技術)의 전달과정(傳達過程)을 분석(分析)해야 되고 (5) 지도원(指導員) 자신의 무장(武裝)을 위(爲)하여 자신(自身)의 기술지도(技術指導) 방법(方法), 인간지도자(人間指導者)로서의 능력향상(能力向上)을 독서(讀書), 교육(敎育), 훈련(訓練) 을 통(通)하여 배워 기술자(技術者)로서 인간지도자(人間指導者)로서 전달자(傳達者)로 서의 교양(敎養)을 가져야 한다. (6) 지도원(指導員)의 활동성과(活動成果)는 지도원(指導員) 자신의 열의(熱意)와 받아들이는 사람의 열의(熱意)에 의(依)하여 좌우(左右)된다. 즉(卽) 지도원(指導員)의 열의(熱意)${\times}$피지도자(被指導者)의 열의(熱意)=지도성과(指導成果) $[L{\times}P=f(L{\cdot}P)]$로 나타난다. 결론적(結論的)으로 지도원(指導員)은 영양개선(營養改善)의 전문적(專門的) 각 요소(各要素)를 깊이 알고 이것을 다시 종합(綜合)하고 체계화(體系化)할 줄 알며 직능별(職能別) 각 지도원(各指導員)과의 상호(相互) 협조(協助)로 서로 보완(補完)하고 새마을 운동(運動)과 그 직장(職場) 또는 환경(環境)여건에 결부(結付)되고 현실적(現實的)으로 행동화(行動化)할 수 있는 단계적(的) 장단기계획(長短期計劃)과 평가방법(評價方法)을 숙지(熟知)하여 또 지도방법(指導方法)에 필요(必要)한 교재(敎材)를 충실(充實)히 준비하여 자신(自身)의 실력(實力)을 충분(充分)히 발휘할 수 있도록 하여 자기 열의(熱意)를 다하고" 영양개선(營養改善)의 선도적(先導的) 점화자(點火者)로서 "계속 뒤에서 미는" 지원자(支援者)로서 사명(使命)을 다할 때 그 역할(役割)을 다하는 것이다.

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Design of a Bit-Serial Divider in GF(2$^{m}$ ) for Elliptic Curve Cryptosystem (타원곡선 암호시스템을 위한 GF(2$^{m}$ )상의 비트-시리얼 나눗셈기 설계)

  • 김창훈;홍춘표;김남식;권순학
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.12C
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    • pp.1288-1298
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    • 2002
  • To implement elliptic curve cryptosystem in GF(2$\^$m/) at high speed, a fast divider is required. Although bit-parallel architecture is well suited for high speed division operations, elliptic curve cryptosystem requires large m(at least 163) to support a sufficient security. In other words, since the bit-parallel architecture has an area complexity of 0(m$\^$m/), it is not suited for this application. In this paper, we propose a new serial-in serial-out systolic array for computing division operations in GF(2$\^$m/) using the standard basis representation. Based on a modified version of tile binary extended greatest common divisor algorithm, we obtain a new data dependence graph and design an efficient bit-serial systolic divider. The proposed divider has 0(m) time complexity and 0(m) area complexity. If input data come in continuously, the proposed divider can produce division results at a rate of one per m clock cycles, after an initial delay of 5m-2 cycles. Analysis shows that the proposed divider provides a significant reduction in both chip area and computational delay time compared to previously proposed systolic dividers with the same I/O format. Since the proposed divider can perform division operations at high speed with the reduced chip area, it is well suited for division circuit of elliptic curve cryptosystem. Furthermore, since the proposed architecture does not restrict the choice of irreducible polynomial, and has a unidirectional data flow and regularity, it provides a high flexibility and scalability with respect to the field size m.

Public Interest and Ownership Regulations in the Media Industry in the Era of Convergence Focused on Domestic Daily Newspapers' Ownership of Broadcasting Station (융합시대 미디어산업의 공익성과 소유규제 국내 종합일간지와 방송의 교차소유 문제를 중심으로)

  • Jun, Young-Beom
    • Korean journal of communication and information
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    • v.46
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    • pp.511-555
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    • 2009
  • Media-related regulations can be classified into two categories; regulations of individual media contents and regulations regarding the entry to and withdrawal from a certain field. In this dissertation, ownership regulations are regarded as legal and political measures so as to prevent the monopoly and oligopoly of public opinion, and to secure its diversity. Every country has its own regulation model according to its particular media environment. Korea too is obliged to actively respond to its environmental changes, at the same time vitalizing the media industry and protecting consumers' rights and interests. Strong political intentions to protect the public interest is necessary when it comes to media regulation policies, especially in the circumstances that public interest is an industrial priority. As the convergence of broadcasting and telecommunications is leading to a major shift in the media industry, the regulation of cross-media ownership is an issue involving potential conflicts among media-owners, non-governmental organizations and the authorities concerned, depending on their various viewpoints regarding the media industry. In this paper, an attempt was made to search necessity of redefining 'public interest', which is the logic behind the restriction of cross-media ownership, and to reconceptualize issues on the centralization and diversity of media. First, an examination of the actual conditions of newspaper companies was carried out in order to reinvestigate domestic cross-media ownership issues, which is represented by the cross-ownership issue of newspapers and broadcasting stations. Next, the dilemma of policies stimulated by the fusion of media was discussed based on cross-media ownership restrictions, and the need for efficient conflict control was suggested. Finally, proposals on the independency and public confidence of media-related policy-making authorities, the rationalization of regulation models, an itemized discussion on cross-media ownership regulation issues, the elaboration of measures for a balanced development among media were made. It could be found that a number of foreign countries were still facing challenges to prevent monopoly and oligopoly of the public opinion and the industry. A solution to settle disagreements about the dilemma of the media industry, including the cross-media ownership regulation issues, must be arranged on the grounds of 'mutual respect of public interest and industrial interest', In Korea, an ease on the ownership regulations adapting to the change in the media industry may be considered, however the softening of the cross-media ownership regulations must be approached with the utmost care. Paradoxically Relieving cross-media ownership regulations may be considered the foundation of a richer field of journalism, where there is no need for concern over the monopoly and oligopoly of public opinion.

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