• Title/Summary/Keyword: gf

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Enzymatic Saccharification of Citrus Peel by Aspergillus sp. GF 015 (분리균 Aspergillus sp. GF015를 이용한 감귤과피(柑橘果皮)의 당화(糖化))

  • Park, Seok Kyu;Sung, Nack Kie;Chun, Hyo Kon
    • Microbiology and Biotechnology Letters
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    • v.13 no.1
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    • pp.59-64
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    • 1985
  • In order to utilize Citrus peel as fermentative substrate of microorganisms, enzymatic saccharification of Citrus peel by the crude enzyme of Aspergillus sp. GF 015 isolated and identified from nature was investigated. When the fungus was cultured at $27^{\circ}C$ for 3 days in wheat bran medium containing 0.6% $NH_4NO_3$ and 0.05% $KH_2PO_4$, the maximal production of the enzyme was observed. Optimal conditions for enzymatic reaction of crude enzyme were 15ml(97.5 unit)/g of enzyme solution to Citrus peel powder ratio, pH4.0, $45^{\circ}C$ of temperature and 12 hours of reaction time. As the result of saccharifying Citrus peel under optimum conditions, reducing sugar on the weight of dry matter was formed 60.2% and saccharifying rate was 76.3%. The sugar solution obtained were mainly composed of glucose, xylose and galacturonic acid. Hydrolyzing enzymes produced by Aspergillus sp. GF 015 were pectinase, cellulase and xylanase.

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A New Arithmetic Unit Over GF(2$^{m}$ ) for Low-Area Elliptic Curve Cryptographic Processor (저 면적 타원곡선 암호프로세서를 위한 GF(2$^{m}$ )상의 새로운 산술 연산기)

  • 김창훈;권순학;홍춘표
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.7A
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    • pp.547-556
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    • 2003
  • This paper proposes a novel arithmetic unit over GF(2$^{m}$ ) for low-area elliptic curve cryptographic processor. The proposed arithmetic unit, which is linear feed back shift register (LFSR) architecture, is designed by using hardware sharing between the binary GCD algorithm and the most significant bit (MSB)-first multiplication scheme, and it can perform both division and multiplication in GF(2$^{m}$ ). In other word, the proposed architecture produce division results at a rate of one per 2m-1 clock cycles in division mode and multiplication results at a rate of one per m clock cycles in multiplication mode. Analysis shows that the computational delay time of the proposed architecture, for division, is less than previously proposed dividers with reduced transistor counts. In addition, since the proposed arithmetic unit does not restrict the choice of irreducible polynomials and has regularity and modularity, it provides a high flexibility and scalability with respect to the field size m. Therefore, the proposed novel architecture can be used for both division and multiplication circuit of elliptic curve cryptographic processor. Specially, it is well suited to low-area applications such as smart cards and hand held devices.

Design of an Efficient User Authentication Protocol Using subgroup of Galois Field (유한체의 부분군을 이용한 효율적인 사용자 인증 프로로콜 설계)

  • 정경숙
    • Journal of the Korea Society of Computer and Information
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    • v.9 no.2
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    • pp.105-113
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    • 2004
  • If the protocol has fast operations and short key length, it can be efficient user authentication protocol Lenstra and Verheul proposed XTR. XTR have short key length and fast computing speed. Therefore, this can be used usefully in complex arithmetic. In this paper, to design efficient user authentication protocol we used a subgroup of Galois Field to problem domain. Proposed protocol does not use GF($p^6$) that is existent finite field, and uses GF($p^2$) that is subgroup and solves problem. XTR-ElGamal based user authentication protocol reduced bit number that is required when exchange key by doing with upside. Also, Proposed protocol provided easy calculation and execution by reducing required overhead when calculate. In this paper, we designed authentication protocol that is required to do user authentication.

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On Implementations of Algorithms for Fast Generation of Normal Bases and Low Cost Arithmetics over Finite Fields (유한체위에서 정규기저의 고속생성과 저비용 연산 알고리즘의 구현에 관한 연구)

  • Kim, Yong-Tae
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.4
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    • pp.621-628
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    • 2017
  • The efficiency of implementation of the arithmetic operations in finite fields depends on the choice representation of elements of the field. It seems that from this point of view normal bases are the most appropriate, since raising to the power 2 in $GF(2^n)$ of characteristic 2 is reduced in these bases to a cyclic shift of the coordinates. We, in this paper, introduce our algorithm to transform fastly the conventional bases to normal bases and present the result of H/W implementation using the algorithm. We also propose our algorithm to calculate the multiplication and inverse of elements with respect to normal bases in $GF(2^n)$ and present the programs and the results of H/W implementations using the algorithm.

The Influence by Stylus Tip Radius and Measuring force on the Stylus Type Surface Roughness Tester (촉침식표면거칠기 측정기에 있어서 촉침의 선단곡률반경과 측정압이 측정에 미치는 영향)

  • Kang, Myung-Soon;Han, Eung-Kyo;Kwon, Dong-Ho;Cho, Nahm-Gyoo
    • Journal of the Korean Society for Precision Engineering
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    • v.3 no.1
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    • pp.69-76
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    • 1986
  • The measuring Method by stylus, which measures surface roughness, has been widely used since G. Schmaltz developed the first equipment of that type. Withe the resent development of the measuring method by stylus, surface foughness testing instruments of the very high magnification ratio, hundreds of thousands, are manu- factured. However, as the techniques of the high precision roughness measurement are being required, the response problems due to the tip shapes and the plastic deformations of measured surface of mild material are to be serious factors. In this study, diamond stylus of tip radius $0.5\mu\textrm{m}$, $2\mu\textrm{m}$, $5\mu\textrm{m}$ and $10\mu\textrm{m}$ were used under the measuring force of 0.01gf, 0.02gf, 0.07gf, 0.4gf and 1.6gf, and from the experimental data, maximum measured value devrements between $2\mu\textrm{mR}$ stylus and $5\mu\textrm{mR}$ stylus, $2\mu\textrm{mR}$ stylus and $10\mu\textrm{mR}$ stylus are 22% and 31%, respectively when the measured value of $2\mu\textrm{mR}$ stylus goes to $0.01\mu\textrm{m Ra}$, $\lambda$ c2.5mm. And it is shown that plastic deformations on the plastic deformations on the measured surface are proportional to W/R(W;measured force, R;stylus tip radius).

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Syntheses and realization of Quaternary Galois Field Sum-Of-Product(QGFSOP) expressed 1-variable functions Permutational Literals (치환리터럴에 의한 Quaternary Galois Field Sum-Of-Product(QGFSOP)형 1-변수 함수의 합성과 실현)

  • Park, Dong-Young;Kim, Baek-Ki;Seong, Hyeun-Kyeong
    • Journal of Advanced Navigation Technology
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    • v.14 no.5
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    • pp.710-717
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    • 2010
  • Even though there are 256 possible 1-qudit(1-variable quantum digit) functions in quaternary logic, the most useful functions are 4!=24 ones capable of representing in QGFSOP expressions by possible permuting of 0,1,2, and 3. In this paper, we propose a permutational literal(PL) representation and a QPL(Quaternary PL) gate which use the operands of a multiplicand A and an augend D in $Ax^C$+D(GF4) operation as a control variable of multi-cascaded PLs. And we also present new PL synthesis algorithms to synthesize QGFSOP expressed 24 (1-qudit) functions by applying three PL operators as ab(mutual permutation), + D(addition), and XA (multiplication). Finally architectures, circuits, and a CMOS implementation to realize proposed PL synthesis algorithms for $Ax^C$+D(GF4) functions are presented.

A Study on the Knit Pattern Considering the Characteristics of Rib Stitch(2) -Focused on $2{\times}1\;and\;2{\times}2$ Rib Stitches (리브조직의 특성을 고려한 니트 패턴 연구(2) -$2{\times}1$ rib 조직과 $2{\times}2$ rib 조직을 중심으로-)

  • Kim, Soo-Ah;Suh, Mi-A
    • The Research Journal of the Costume Culture
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    • v.13 no.1
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    • pp.47-59
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    • 2005
  • This study aims to measure stretch rate of standard weight in the $2{\times}1$ rib stitch and $2{\times}2$ rib stitch, and to apply features of rib stitch to the knit pattern. The reviewer examined the sample knit for test with 100% wool, $2/48's{\times}2$, 12 gauge, and then made knit patterns and sample clothes for test considering stretch rate of standard weight of 10gf, 15gf, 20gf, 25gf based on the results from the former test, and finally estimated the try-outs for sample clothes. This study came out with the following results: From the functional estimate of knit patterns made by standard stretch rate of each stitch, the 20gf weight sample clothes of $2{\times}1$ and $2{\times}2$ rib stitchs were in high estimate. For the bust, B/4~ -4.6cm knit pattern was made of $2{\times}1$ rib stitch, B/4~5.3cm of $2{\times}2$ rib stitch. In conclusion, because $2{\times}1$ and $2{\times}2$ rib stitchs has the much higher stretch rate in the direction of the course than $0{\times}0$ ad $1{\times}1$ rib stitchs, high stretch rate of standard weight should be applied to the case of making knit wear. It is expected that this will lead stable sizing and measurement system when used in making knit patterns, and satisfy knit wearers' various needs.

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A Study on the Knit Pattern Considering the Characteristics of Rib Stitch(1) - Focused on 0${\times}$0 and 1${\times}$1 Rib Stitches (리브조직의 특성을 고려한 니트 패턴 연구(1) -0${\times}$1 rib 조직과 1${\times}$1 rib 조직을 중심으로)

  • 김수아;서미아
    • The Research Journal of the Costume Culture
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    • v.12 no.5
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    • pp.769-780
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    • 2004
  • This study aims to measure stretch rate of standard weight in the direction of the knit stitch course by the difference in the way of weaving rib stitch, the most elastic stitch of all the knit stitches and to apply features of rib stitch to the knit pattern. The reviewer examined the sample knit for test with 100% wool, 2/48's 2, 12 gauge, and then made knit patterns and sample clothes for test considering stretch rate of standard weight of 10gf, l5gf, 20gf, 25gf based on the results from the former test, and finally estimated the try-outs for sample clothes. This study came out with the following results. From the functional estimate of knit patterns made by standard stretch rate of each stitch, the l5gf weight sample clothes of 0×0 and 1×1 rib stitches looking similar to plain stitch. For the bust, B/4-1.0㎝ knit pattern was made of 0×0 stitch, B/4-1.2㎝ of 1×1 rib stitch. In conclusion, because rib stitch has the much higher stretch rate in the direction of the course than other stitches, low stretch rate of standard weight should be applied to the case of making knit wear. It is expected that this will lead stable sizing and measurement system when used in making knit patterns, and satisfy knit wearers' various needs.

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VLSI Design of an Improved Structure of a $GF(2^m)$ Divider (확장성에 유리한 병렬 알고리즘 방식에 기반한 $GF(2^m)$나눗셈기의 VLSI 설계)

  • Moon San-Gook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.3
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    • pp.633-637
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    • 2005
  • In this contribution, we developed and improved an existing GF (Galois field) dividing algorithm by suggesting a novel architecture for a finite field divider, which is frequently required for the error correction applications and the security-related applications such as the Reed-Solomon code, elliptic curve encryption/ decryption, is proposed. We utilized the VHDL language to verify the design methodology, and implemented the architecture on an FPGA chip. We suggested the n-bit lookup table method to obtain the throughput of 2m/n cycles, where m is the order of the division polynomial and n is the number of the most significant lookup-bits. By doing this, we extracted the advantages in achieving both high-throughput and less cost of the gate areaon the chip. A pilot FPGA chip was implemented with the case of m=4, n=2. We successfully utilized the Altera's EP20K30ETC144-1 to exhibit the maximum operating clock frequency of 77 MHz.

Clothing Pressure of selected Support Panty Stockings

  • Park, Jeong-Eun;Sung, Su-Kwang;Song, Min-Kyu
    • Fashion & Textile Research Journal
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    • v.2 no.5
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    • pp.430-436
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    • 2000
  • The purpose of the study was to obtain the basic data on the self-adjusting ability of the support panty stockings. Ten healthy women in the twenties were selected as subjects and clothing pressure of 9 support panty stockings made of single covered yarn (SCY) and double covered yarn (DCY) were measured under the standard environmental condition for the study. Data was analysed statistically according to body postures, sides, and parks. The results were as follows: Clothing pressure according to body posture was order of 'sitting-on-a-chair', 'stepping-up-a-stair', and 'standing'. High clothing pressure was obtained in the parts of calf ($9.4gf/cm^2$) in 'standing' and knee (9.7 and $16.5gf/cm^2$) in both 'stepping-up-a-stair' and 'sitting-on-a-chair', respectively. The order of clothing pressure with body sides was 'front', 'side', and 'back'. The highest clothing pressure was knee ($18.8gf/cm^2$) on the front, thigh ($8.8gf/cm^2$) on the side, and calf ($6.4gf/cm^2$) on the back. Clothing pressure of DCY at abdomen and knee was a little higher than those of SCY 3. In terms of material structure variation, clothing pressure of thigh, calf and ankle with SCY was a little higher than those with DCY, while clothing pressure of abdomen and knee with DCY was a little higher than those with SCY.

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