• Polymer(Korea)
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• v.24 no.5
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• pp.701-712
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• 2000

The continuous fiber reinforced composites of GF/PA were fabricated using a pultrusion resin impregnation apparatus and cut into pellets of 6 mm length. GF/PA pellets were then melt-mixed with PP resin to prepare new types of ternary composites, GF/PA/PP. Mechanical and rheological properties of such composites revealed to be better than conventional ternary composites due to the longer average glass fibers. Measurements also showed that the mechanical properties of the composites prepared by direct injection molding were higher than those of the composites prepared by injection molding followed by extrusion. To improve adhesions of fiber surfaces and polymer matrix, PP-MAH (maleic anhydride) has been introduced in the GF/PA/PP composites as a compatibilizer. It was found that PP-MAH did indeed improve surface adhesion between fibers and polymer matrix and that, as a result, various mechanical properties were markedly enhanced. Visualization of the phase structure in the samples was done by means of SEM. The surfaces of glass fibers in GF/PA/PP composites revealed that the fibers remained to be encapsulated by PA resin. However, pre-encapsulation did not persist in GF/PA/PP/PP-MAH composites due to the improvement of surface adhesion between fibers and polymer matrix, although resin sticking to the fiber was observed.

• Elastomers and Composites
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• v.52 no.1
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• pp.59-68
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• 2017

The effect on the hydrolysis resistance properties by the addition of maleic anhydride grafted EMDM (MA-g-EPDM) and PP (MA-g-PP) to a PA66/GF composite was investigated with respect to the mechanical properties, thermal properties, and morphology. The degree of hydrolysis of the PA66/GF composite was measured using py-GC/MS analysis. When compared to the PA66/GFcomposite in MEG/water solution, the composites where MA-g-EPDM and MA-g-PP were added to PA66/GF showed a higher degree of hydrolysis resistance, impact strength, and thermal properties, whereas their tensile strength, tensile modulus, flexural strength and flexural modulus decreased. As immersion time in the solution increases, the rate of tensile strength drop of the MA-g-PP added composite appeared lower than that of the PA66/MA-g-EPDM/GF and PA66/GF composites. The py-GC/MS analysis confirmed the formation of PA66 hydrolysis reaction by products such as carboxylic acid and alkylamine with increasing immersion time.

• KSTLE International Journal
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• v.3 no.1
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• pp.26-29
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• 2002

The International Lubricant Standardization and Approval Committee (ILSAC) GF-3 passenger car engine oil specification has been introduced commercially in July 2001. The new specification oil provides superior performance in terms of fuel economy, control of high temperature deposits, and oil consumption. These enhanced performances of GF-3 engine oil need high quality base oil as well as a better additive system. In this paper, the effect of base oil on various performances of ILSAC GF-3 engine oil was investigated. From the GF-3 sequence engine tests, Group III base oil shows better performance in fuel economy retention, oxidation and varnish control than combination of group III and group II or group III and group 1.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.768-771
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• 2008

This paper presents an algorithm for generating inverse element over finite fields $GF(3^m)$, and constructing method of inverse element generator based on inverse element generating algorithm. The method need to compute inverse of an element eve. $GF(3^m)$ which corresponds to a polynomial eve. $GF(3^m)$ with order less than equal to m-1. Here, the computation is based on multiplication, square and cube method derived from the mathematics properties over finite fields.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.1 no.1
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• pp.29-37
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• 1991

several variants of the Diffie-Hellman public key distribution are examined, and a simkple and relatively secure public key distribution protocol is introduced. Using a normal basis of GF(2), this protocol is implemented, and simulated in software. A program is developed, whereby a normal basis is effectively searched for fost multiplication in GF(2).

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.5
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• pp.29-36
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• 2004

This study focuses on the arithmetical methodology and hardware implementation of low-system-complexity multiplier over GF(2$^{m}$ ) using the trinomial of degree a The proposed parallel-in parallel-out operator is composed of MR, PP, and MS modules, each can be established using the regular array structure of AND and XOR gates. The proposed multiplier is composed of $m^2$ 2-input AND gates and $m^2$-1 2-input XOR gates, and the propagation delay is $T_{A}$+(1+[lo $g_2$$^{m}$ ]) $T_{x}$ . Comparison result of the related multipliers of GF(2$^{m}$ ) are shown by table, it reveals that our operator involve more regular and generalized then the others, and therefore well-suited for VLSI implementation. Moreover, our multiplier is more suitable for any other GF(2$^{m}$ ) operational applications.s.

• Korean Journal of Remote Sensing
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• v.34 no.5
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• pp.777-786
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• 2018

GF (Guided Filtering) is a representative image processing technique to effectively remove noise while preserving edge information in the digital image. In this paper, we proposed a unsupervised change detection method for the KOMPSAT-3 satellite image using the GF and evaluated its performance. In order to utilize GF for the unsupervised change detection, cross-sharpened images were generated based on GF, and CVA (Change Vector Analysis) was applied to the generated cross-sharpened images to extract the changed area in the multitemporal satellite imagery. Experimental results using KOMPSAT-3 satellite images showed that the proposed method can be effectively used to detect changed regions compared with CVA results based on existing cross-sharpened images.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.1_2
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• pp.51-58
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• 2004

Most of pubic-key cryptosystems are built on the basis of arithmetic operations defined over the finite field GF$GF(2^m)$ .The other operations of finite fields except addition can be computed by repeated multiplications. Therefore, it is very important to implement the multiplication operation efficiently in public-key cryptosystems. We propose an efficient bit-parallel normal basis multiplier for$GF(2^m)$ fields defined by All-One Polynomials. The gate count and time complexities of our proposed multiplier are lower than or equal to those of the previously proposed multipliers of the same class. Also, since the architecture of our multiplier is regular, it is suitable for VLSI implementation.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.35-49
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• 2003

In this study, in an attempt to search for functional cosmetic ingredients from higher fungal, we have produced exopolysaccharides (GF-l, approximately carbohydrate 75％, protein 25％) and polysaccharide (GF-2) of mycelium extract, by submerged culture of Grifolafrondosa. For applications in anti-aging cosmetic field, we investigated the diverse biological activities. Antioxidant activity and inhibition of Matrixmetalloproteinases (MMPs) were investigated enzymatic assays by measuring the superoxide scavenging activity using xanthine-xanthine oxidase system and the proteolytic activity of MMPs using EnzChek Collagenase/Gelatinase kits, respectively. GF-l polysacchairde showed inhibition of superoxide radical by 90％ at a concentration of 0.2％ (w/v) and inhibition of collagenase by 45％ at 0.2％ (w/v). GF-2 polysaccharide of mycelium extract also exhibited good antioxidant activity. However, MMPs inhibition activity was relatively lower level compared to GF-l polysaccharides. The treatment of human dermal fibroblast (HDF) with GF-l and GF-2 polysaccharides increased the proliferation of fibroblast by approximately 23-25％ at a concentration of 0.5％ (w/v), also showed collagen synthesis increase in HDF by about 50％ at 0.5％ (w/v) compared to that of untreated control. We also report the moisturizing effects of polysaccharides in cosmetic products (O/W emulation) and its own ingredient, in vitro and in vivo. The GF-1 polysaccharide showed higher moisturizing ability than sodium hyaluronate, which is the most commonly used moisturizers ingredient. These results suggest the GF-l polysaccharide, protein-bound polysaccharide, may be used as an ingredient for new moisturizing and anti-aging cosmeceuticals.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.10
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• pp.1216-1224
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• 1988

In this paper, it is presented element generation, addition, multiplication and division algorithm over GF ($2^m$) to calculate multiple-valued logic function. The results of addition and multiplication among these algorithms are applied to the current mode CMOS circuits with ROM structure to design of adder and multiplier on GF ($2^m$). Table-lookup and Euclid's algorithm are required the computation in large quentities when multiple-valued logic functions are developed on GF ($2^m$). On the contrary the presented operation algorithms are prefered to the conventional methods since they are processed without relation to increasing degree m in the general purpose computer. Also, the presened logic circuits are suited for the circuit design of the symmetric multiplevalued truth-tables and they can be implemented addition and multiplication on GF ($2^m$) simultaueously.