• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1C
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• pp.8-13
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• 2006

A new RS(Reed Solomon) Decoder design method, using Galois Subfield GF($2^4$) Multiplier, is described. The Decoder is designed using Normalized error position stored ROM. Here New Inverse Calculator in GF($2^8$) is designed, which is simpler and faster than the classical GF($2^8$) direct inverse calculator, using the Galois Subfield GF($2^4$) Arithmatic operator.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.8 no.2
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• pp.27-36
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• 1998

최근들어 타원곡선 암호법(ECC)이 RSA암호법을 대체할 것으로 기대되면서ECC의 연산속도를 결정하는 중요한 요소인 유한체의 연산 속도에 관심이 고조되고 있다. 본 논문에서는 Modified 최적 정규 기저의 성질 규명과 GF(q)(q=2$^{k}$ , k=8또는 16)위에서 GF(q$^{m}$ )(m: 홀수)의 Mofdified trinomial 기가 존재하는 m들을 제시하고, GF(r$^{n}$ )위에서 GF(r$^{nm}$ )dml Modified 최적 정규기저와 Modified trinomial 기저를 이용한 연산의 회수와 각 기저를 이용한 연산의 회수와 각 기저를 이용한 유한체 GF(q$^{m}$ )의 연산을 S/W화한 결과를 비교 하였다.

• The Research Journal of the Costume Culture
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• v.10 no.2
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• pp.178-185
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• 2002

The purpose of this study was to measure distribution of clothing pressure on breast in brassiere according to body shape and motion, and the position of hook-and-eye on brassiere, and to get basic data for comfortable brassiere design. Clothing pressure was measured from 8 female subjects under wearing trials in climatic chamber. When brassiere was tied together with inner or outer hook-and-eye, clothing pressure under the condition were 10.2 and 9.6 gf/cm², respectively. With the degree between main body and arms increased from 0° to 45° and 90°to the front, clothing pressure decreased from 10.2 to 9.6 gf/cm², and then increased to 10.4 gf/cm² When the decree was increased from 45° to 70° to the flank, the pressure increased from 9.3 to 10.6 gf/cm². Fat body shape recorded 10.8 gf/cm², and lean body shape recorded 9.5 gf/cm² of clothing pressure by wearing brassiere. Clothing pressures of brassiere were 7.8g gf/cm² in front, 9.5 gf/cm² in side, 12.8 gf/cm² in the back side. Therefore, clothing pressure of brassiere was influenced to the greater extent by body shape and measuring points on human body than by the position of hook-and-eye and body motion.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.6 no.4
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• pp.97-106
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• 1996

In this paper, we define an equivalence relation on the group of all permutations over the finite field GF($2^n$) and show each equivalence class has common cryptographic properties. And, we classify all exponent permutations over GF($2^7$) and GF($2^8$). Then, three applications of our results are described. We suggest a method for designing $n\;{\times}\;2n$ S(ubstitution)-boxes by the concatenation of two exponent permutations over GF($2^n$) and study the differential and linear resistance of them. And we can easily indicate that the conjecture of Beth in Eurocrypt '93 is wrong, and discuss the security of S-box in LOKI encryption algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.1
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• pp.143-152
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• 2012

In this paper hardware implementation of GF($2^{191}$) elliptic curve cryptographic coprocessor which supports 7 operations such as scalar multiplication(kP), Menezes-Vanstone(MV) elliptic curve cipher/decipher algorithms, point addition(P+Q), point doubling(2P), finite-field multiplication/division is described. To meet structure resistant against simple power analysis, the ECC processor adopts the Montgomery scalar multiplication scheme which main loop operation consists of the key-independent operations. It has operational characteristics that arithmetic units, such GF_ALU, GF_MUL, and GF_DIV, which have 1, (m/8), and (m-1) fixed operation cycles in GF($2^m$), respectively, can be executed in parallel. The processor has about 68,000 gates and its simulated worst case delay time is about 7.8 ns under 0.35um CMOS technology. Because it has about 320 kbps cipher and 640 kbps rate and supports 7 finite-field operations, it can be efficiently applied to the various cryptographic and communication applications.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.3
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• pp.9-21
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• 2008

In this paper, we revisit a generally accepted opinion: implementing Elliptic Curve Cryptosystem (ECC) over GF$(2^m)$ on sensor motes using small word size is not appropriate because partial XOR multiplication over GF$(2^m)$ is not efficiently supported by current low-powered microprocessors. Although there are some implementations over GF$(2^m)$ on sensor motes, their performances are not satisfactory enough due to the redundant memory accesses that result in inefficient field multiplication and reduction. Therefore, we propose some techniques for reducing unnecessary memory access instructions. With the proposed strategies, the running time of field multiplication and reduction over GF$(2^{163})$ can be decreased by 21.1% and 24.7%, respectively. These savings noticeably decrease execution times spent in Elliptic Curve Digital Signature Algorithm (ECDSA) operations (Signing and verification) by around $15{\sim}19%$.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.387-394
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• 2020

In this research, a physical property test of CLSM, which can safely and effectively utilize a great number of industrial byproducts and waste types, was used to review the applicability of GBFS, FNS, and FGB, as well as their field applicabilities as cavity fillers, and the following conclusions have been reached. first, For CLSM utilizing GBFS, FNS, and FGB, it was revealed that a proper mixing of over 30% of GBFS and FNS or within 5% of FGB is effective in improving the fluidity for field application. second, It was revealed that GF15B5 can suppress bleeding at a similar level as the base, whereas GF30B5 can do so at about 0.17% compared to the base. It was also verified that GF15, GF30, and GF45 can suppress bleeding at about 0.2%, 0.26%, and 0.3%, respectively, compared to the base. third, Both GF15B5 and GF30B5 exceeded 0.4MPa in 7day strength tests to satisfy the field application and, also, the rates of increase of their initial strengths were found to be 323% and 233% higher than the base, respectively. Meanwhile, the 7day strength test of GF, which utilizes GBFS and FNS, also reached over 0.2MPa for field application, and it was revealed that GF15, GF30, and GF45 show 160%, 237%, and 185% higher strength increase rates, respectively, compared to the base.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1996.11a
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• pp.165-174
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• 1996

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.4
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• pp.201-213
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• 1989

This study is just to be carried out to grasp the efficiency of jet stream excavating for the ground. Changing the dynamic pressure, nozzle diameter, distance off the ground, we measured the impulse, the excavated depth, the excavated width. According as each dynamic pressure increases from 100 to $500gf/cm^2$, the impulse of the jet stream increases from 43 to 114gf, from 52 to 227gf, from 114 to 506gf, from 137 to 768gf, in 4, 6, 8, 10mm nozzles respectively, but it makes no difference in the value of distance within 50cm off ground. The excavated depth increases at the invariable rate in accordance with nozzle diameter, dynamic pressure, nozzle distance. We obtain the equations relevant to the ground I, II as follows: $$L_I=[0.01(H/r-100) -0.43\cdot\iota+11.78]{\cdot}D/4$$ $$L_{II}=[0.03(H/r-100) -0.34\cdot\iota+6.39]{\cdot}D/4$$ where, $L_I,\;L_{II}$ are respectively the excavated depths of the ground I, II, cm; H is the dynamic pressure, $gf/cm^2\;:\;\iota$ is the distance off the ground, cm; D is Nozzle diameter, mm; r is the specific weight, $1gf/cm^2$.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.304-309
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• 1993

The composition of soluble neutral carbohydrates in jerusalem artichoke tubers was measured and compared according to harvest dates and storage temperatures using HPLC. The breakdown of inulin $({\ge}GF8)$ into sucrose and fructo-oligosaccharides (GF2-GF7) was highest on November just after cold-shock. The composition of sucrose and fructo-oligosaccharides on March was much higher than that on September of previous year. Inulin $({\ge}GF8)$ proportion decreased from 66.4% to 33.1% but the proportion of fructo-oligosaccharides (GF2-GF7) and sucrose increased from 25% to 61% and from 3.4% to 13.6%, respectively. The storage at a low temperature $(4^{\circ}C)$ for 34 days increased the composition as well. However, the amount of fructo-oligosaccharides was decreased when the tubers harvested in March were stored at high temperature $(25^{\circ}C{\sim}40^{\circ}C)$. For the maximam yield of fructo-oligosaccharides in jerusalem artichoke, it is concluded that the tubers be harvested in March and/or stored at the low temperature.