• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.409-416
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• 2014

In H/W implementation for the finite field, the use of normal basis has several advantages, especially the optimal normal basis is the most efficient to H/W implementation in $GF(2^m)$. The finite field $GF(2^m)$ with type I optimal normal basis(ONB) has the disadvantage not applicable to some cryptography since m is even. The finite field $GF(2^m)$ with type II ONB, however, such as $GF(2^{233})$ are applicable to ECDSA recommended by NIST. In this paper, we propose a bit-parallel multiplier over $GF(2^m)$ having a type II ONB, which performs multiplication over $GF(2^m)$ in the extension field $GF(2^{2m})$. The time and area complexity of the proposed multiplier is the same as or partially better than the best known type II ONB bit-parallel multiplier.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.3
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• pp.113-123
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• 2007

This paper presents a high-performance elliptic curve cryptographic processor over $GF(2^m)$. The proposed design adopts Lopez-Dahab Montgomery algorithm for elliptic curve point multiplication and uses Gaussian normal basis for $GF(2^m)$ field arithmetic operations. We select m=163 which is the smallest value among five recommended $GF(2^m)$ field sizes by NIST and it is Gaussian normal basis of type 4. The proposed elliptic curve cryptographic processor consists of host interface, data memory, instruction memory, and control. We implement the proposed design using Xilinx XCV2000E FPGA device. Based on the FPGA implementation results, we can see that our design is 2.6 times faster and requires significantly less hardware resources compared with the previously proposed best hardware implementation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.5
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• pp.979-984
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• 2015

In this paper, we proposed a Semi-Systolic multiplier of $GF(2^n)$ with Type II optimal Normal Basis. Comparing the complexity of the proposed multiplier with Chiou's multiplier proposed in 2012, it is saved $2n^2+44n+26$ in total transistor numbers and decrease 4 clocks in time delay. This means that, for $GF(2^{333})$ of the field recommended by NIST for ECDSA, the space complexity is 6.4% less and the time complexity of the 2% decrease. In addition, this structure has an advantage as applied to Chiou's method of concurrent error detection and correction in multiplication of $GF(2^n)$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.12
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• pp.80-86
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• 2003

Elliptic curve cryptosystem(ECC) offers the highest security per bit among the known publick key system. The benefit of smaller key size makes ECC particularly attractive for embedded applications since its implementation requires less memory and processing power. In this paper, we propose a new multiplier structure with configurable output sizes and operation cycles. The number of output bits can be freely chosen in the new architecture with the performance-area trade-off depending on the application. Using the architecture, a 193-bit normal basis multiplier and inversion unit are designed in GF(2$^{m}$ ). It is implemented using HDL and 0.35${\mu}{\textrm}{m}$ CMOS technology and the operation is verified by simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1C
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• pp.140-148
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• 2008

Using the self duality of an optimal normal basis(ONB) of type II, we present a bit parallel and bit serial systolic arrays over GF($2^m$) which has a low hardware complexity and a low latency. We show that our multiplier has a latency m+1 and the basic cell of our circuit design needs 5 latches(flip-flops). Comparing with other arrays of the same kinds, we find that our array has significantly reduced latency and hardware complexity.

• Korean Journal of Community Nutrition
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• v.14 no.3
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• pp.295-305
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• 2009

In order to investigate how to maintain normal weight under independent living conditions, twenty female university students were enrolled and asked to complete a questionnaire over a 10- day study period. T-test, Spearman's correlation and multiple regression analysis were applied to describe characteristics of weight maintainers' habits on a daily basis. The results were as follows: They always comsumed small or moderate-sized meals. $2{\sim}3$ co-eaters usually had dinner together at home while not watching TV. They also showed healthy eating behaviors such as no snacking, very little amounts of soft drinks, coffee and alcohol consumption. The always normal weight maintainers, however, were not physically active at all. When being with co-eater(s), they ate larger-sized dinners (${\beta}$ = 0.585, $R^2$= 30.6), and the more co-eaters they had at the dinner table, the greater BMI they got (${\beta}$ = 0.547, $R^2$= 29.9). As a result of this study, encouraging young adult people to exercise on a regular basis is required, even though they seem to succeed in maintaining normal weight without being active physically. Further study is necessary to investigate how co-eaters would influence the amount of food eaten.

• The korean journal of orthodontics
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• v.14 no.2
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• pp.263-272
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• 1984

This study was undertaken to examine the extent to which tooth size and jaw size each contribute to dental crowding. Two groups of dental casts were selected on the basis of dental crowding. One group, consisting of 94 pairs of dental casts (46 males and 48 females) with normal occlusion. A second group, consisting of 84 pairs of dental casts (98 males and 46 females) with crowding. The results were as follows. 1. Means and standard deviations of the two groups were used to compare the two groups. 2. Significant differences were observed between two groups on the basis of tooth size, arch dimension and arch perimeter. 3. Between noncrowded group and crowded group, was crowded group was found to have large troth size than noncrowded group, while smaller arch dimension and perimeter. 4. Significant differences were observed between males and females on the basis of tooth size, arch dimension and arch perimeter. 5. Author found ideal arch shape of normal occlusion.

• Journal of applied mathematics & informatics
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• v.30 no.5_6
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• pp.951-969
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• 2012

In this paper, we propose a class of meshless collocation approaches for the solution of time dependent partial differential algebraic equations (PDAEs) in terms of a radial basis function interpolation numerical scheme. Kansa's method and the Hermite collocation method (HCM) for PDAEs are given. A sensitivity analysis of the solutions from different shape parameter c is obtained by numerical experiments. With use of the random collocation points, we have obtain the more accurate solution by the methods than those by the finite difference method for the PDAEs with index-2, i.e, we avoid the influence from an index jump of PDAEs in some degree. Several numerical experiments show that the methods are efficient.

• The Research Journal of the Costume Culture
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• v.10 no.1
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• pp.28-36
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• 2002

The purposes of the study were to investigate the effect of garment category, fashion-level and wearer's body type on the basis of temporal stability and to extend the contextual framework. The result was as follows 1) On the basis of temporal stability, Korean style, classic style, and large body type have more temporal stability than western style, fashionable style, normal body type. 2) On the basis of temporal stability of impression dimension, impression of appearance knave most temporal stability, next good-bad, next evaluation, next potency, and sociability. 3) In an interaction effect between measuring time and impression of evaluation, western, fashionable, classic style have the greatest interaction effect. In an interaction effect between measuring time and impression of appearance, western style, normal body type have the greatest interaction effect. In an interaction effect between measuring time and impression of good-bad, western, fashionable style have the greatest interaction effect. It is concluded that the results support the context framework on impression formation.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2576-2578
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• 2001

Elliptic curve cryptosystems based on discrete logarithm problem in the group of points of an elliptic curve defined over a finite field. The discrete logarithm in an elliptic curve group appears to be more difficult than discrete logarithm problem in other groups while using the relatively small key size. An implementation of elliptic curve cryptosystems needs finite field arithmetic computation. Hence finite field arithmetic modules must require less hardware resources to archive high performance computation. In this paper, a new architecture of finite field multiplier using conversion scheme of normal basis representation into polynomial basis representation is discussed. Proposed architecture provides less resources and lower complexity than conventional bit serial multiplier using normal basis representation. This architecture has synthesized using synopsys FPGA express successfully.