• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.6B
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• pp.709-716
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• 2001

반복 복호 알고리듬에 의해 복호화된 터보 코드는 가산성 백색 가우시안 잡음(AWGN) 채널 환경에서 이론적으로 Shannon의 한계에 근접한 뛰어난 코딩 이득을 나타내는 것으로 보여지고 있다. 그러나, 터보 코드의 성능은 터보 부호화기에서 프레임의 크기 즉, 인터리버의 크기에 의존한다. IMT-2000과 같은 이동 통신 채널 환경에서 음성을 전송하는 경우에는 터보 코드의 프레임 크기는 매우 작다. 그리고, 그것은 터보 코드의 성능을 떨어뜨리는 직접적인 원인이 된다. 본 논문에서는 차세대 이동 통신 시스템에서 프레임 크기가 작은 음성 프레임을 이용하여 터보 코드의 성능을 검증하며, 작은 프레임 크기에 알맞은 3개의 직렬 MAP(Maximum A Posteriori probability) 복호기를 이용한 반복 복호의 터보 코드를 제안하고 부호율 1/3, 구속장의 길이 3 또는 4, 프레임 크기 24, 192 비트에 대하여 컴퓨터 모의실험을 통해 터보 코드의 성능을 분석한다.

• Bulletin of the Korean Mathematical Society
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• v.58 no.4
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• pp.973-981
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• 2021

Let R be a commutative ring with identity 1, n ≥ 3, and let 𝒯_n(R) be the linear Lie algebra of all upper triangular n × n matrices over R. A linear map 𝜑 on 𝒯_n(R) is called to be strong commutativity preserving if [𝜑(x), 𝜑(y)] = [x, y] for any x, y ∈ 𝒯_n(R). We show that an invertible linear map 𝜑 preserves strong commutativity on 𝒯_n(R) if and only if it is a composition of an idempotent scalar multiplication, an extremal inner automorphism and a linear map induced by a linear function on 𝒯_n(R).

• International Journal of Oral Biology
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• v.47 no.1
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• pp.1-8
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• 2022

Inflammation is a protective mechanism against pathogens, but if maintained continuously, it destroys tissue structures. Aggregatibacter actinomycetemcomitans is a gram-negative, facultative anaerobic bacterium often found in severe periodontitis. A. actinomycetemcomitans invades epithelial cells and triggers inflammatory response in the immune cells. In this study, we investigated the effect of water-soluble rosehip extract on A. actinomycetemcomitans-induced inflammatory responses. A human monocytic cell line (THP-1) was differentiated to macrophages by phorbol 12-mystristate 13-acetate treatment. The cytotoxic effect of extract was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The effects of extract on bacterial growth were examined by measuring the optical densities using a spectrophotometer. THP-1-derived macrophages were infected A. actinomycetemcomitans after extract treatment, and culture supernatants were analyzed for cytokine production using enzyme-linked immunosorbent assay. Protein expression was measured by western blotting. Extract was not toxic to THP-1-derived macrophages. A. actinomycetemcomitans growth was inhibited by 1% extract. The extract suppressed A. actinomycetemcomitans-induced tumor necrosis factor-α, interleukin (IL)-1β, and IL-8 production. It also decreased mitogen-activated protein kinase (MAP kinase) and nuclear factor-κB (NF-κB) phosphorylation. Moreover, the extract inhibited the expression of inflammasome components, including nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3, Absent in Melanoma 2, and apoptosis associated speck-like protein containing a CARD. And cysteine-aspartic proteases-1 and IL-1β expression were decreased by the extract. In summary, extract suppressed A. actinomycetemcomitans growth and decreased inflammatory cytokine production by inhibiting activation of MAP kinase, NF-κB, and inflammasome signaling. Rosehip extract could be effective in the treatment of periodontal inflammation induced by A. actinomycetemcomitans infection.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.1
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• pp.29-38
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• 2012

Due to the rapid development of network environment and wireless communication technology, the distribution of digital video has made easily and the importance of the protection for digital video has been increased. This paper proposes the digital video encryption system based on multiple chaos maps for MPEG-2 video encoding process. The proposed method generates secret hash key of having 128-bit characteristics from hash chain using Tent map as a basic block and generates $8{\times}8$ lattice cipher by applying this hash key to Logistic map and Henon map. The method can reduce the encryption overhead by doing selective XOR operations between $8{\times}8$ lattice cipher and some coefficient of low frequency in DCT block and it provides simple and randomness characteristic because it uses the architecture of combining chaos maps. Experimental results show that PSNR of the proposed method is less than or equal to 12 dB with respect to encrypted video, the time change ratio, compression ratio of the proposed method are 2%, 0.4%, respectively so that it provides good performance in visual security and can be applied in real time.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.23 no.3
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• pp.11-32
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• 2010

Objective : The aim of this study is to determine the effects of Dendrobii herba extract and Punica granatum extract on skin disease and skin beauty. Methods : To investigate in vitro anti-oxidant activity assay, ethanol extracts of medicinal plants tested by DPPH radical, xanthine oxidase activity. In the next experiment, to investigate anti-inflammatory activity assay, examined by relations in NO synthesis, IL-$1{\beta}$, IL-6, TNF-${\alpha}$, NF-${\kappa}B$, COX-2, MAP kinase. To study Skin wrinkle formation effect, we were examined by tyrosinase activities, melanin synthesis in MNT-1 cell. Results : 1. In an anti-oxidant test, Dendrobii and Punica granatum extract showed high radical scavenging activity. 2. In an anti-inflammatory test, Dendrobii herba and Punica granatum extract weakly inhibited the lipopolysaccharide(LPS)-induced nitric oxide(NO) release from RAW 246.7 macrophage cells. Dendrobii herba and Punica granatum extract also inhibited LPS-induced IL-$1{\beta}$ and COX-2 expressions. The inhibitory effect of Dendrobii herba and Punica granatum extract on macrophage activation were via the inhibition of NF-${\kappa}B$, evidenced by transient transfection assay. however, Dendrobii herba and Punica granatum extract did not have any effects about activation of Jun-N-terminal kinase(JNK) and inhibition of p38 MAP kinase in RAW 264.7 cells. 3. In the skin wrinkle formation assay, Dendrobii herba and Punica granatum extract weakly inhibited collagenase and elastase, however it was not statistically significant. 4. In the skin whitening assay, Dendrobii herba and Punica granatum extract weakly inhibited tyrosinase activity, however, it was not statistically significant. They did not have any effect on melanin synthesis, indicating that they could not be applicable for skin whitening. Conclusion : Dendrobii herba extract and Punica granatum extract may play a significant role in skin disease and skin beauty.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.457-463
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• 2005

The use of the internet to facilitate commerce among companies promises vast benefits. Lots of e-marketplaces are building for several industries such as chemistry, airplane, and automobile industries. This study proposed new B2B EC business model for the shipping industry which concerns relatively massive fixed assets to be fully utilized. To be successful the proposed model gives participants to support useful information. To do this the expert system is constructed as the hybrid prediction system of neural network (NN) and memory based reasoning (MBR) with self-organizing map (SOM) and knowledge augmentaton technique using qualitative reasoning (QR). The expert system supports participants useful information coping with dynamic market environment. with this transportation companies are induced to participate in the proposed e-marketplace and helped for exchanges easily. Also participants would utilize their assets fully through B2B exchanges.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.88.1-88.1
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• 2011

We present the FIMS/SPEAR FUV continuum map of The Taurus - Auriga - Perseus (TPA) complex, which is one of the largest local association of dark clouds located in (l,b)~([152,180],[-28,0]). We also present the result of FUV dust scattering simulation, which is based on Monte Carlo Radiative Transfer(MCRT) technique. Before the simulation we generate the model cloud using Hipparcos 77834 stars and the calculation of their E(B-V). From the density-integrated image and the cross section image of the modeled cloud we confirmed that the Taurus cloud is located in ~130pc. The cloud north of the California nebula is known for its two layered structure and we confirm that using the cross section image of the modeled cloud. In our modeled cloud, that two clouds are located at ~130pc and at ~300pc, respectively. Over the whole region the result image of simulation is well correlated with the diffuse FUV observed with FIMS/SPEAR. The dense core of the Taurus cloud, however, is not revealed completely in the map.

• Food Science of Animal Resources
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• v.42 no.1
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• pp.153-174
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• 2022

This trial was conducted to evaluate the effect of overwrap, vacuum, and modified atmosphere packaging (MAP) on poultry breast fillets' microbiological, biochemical shelf life and sensory attributes. The fillets were divided into 4 groups, and each of the treatments was replicated 3 times with 60 breast fillets. The first group was a control group with overwrap packaging; the second group was vacuum packed (VP); the third and fourth groups were MAP-1: 0% O₂, 40% CO₂, 60% N₂, and MAP-2: 20% O₂, 40% CO₂, 40% N₂. The microbiological and biochemical analyses were performed for the total viable count, coliform count, Pseudomonas count, Salmonella count, total volatile basic nitrogen (TVB-N), pH, cooking loss, color, lipid oxidation, tenderness, and sensory analysis. The data were analysed through two-way ANOVA by Minitab (Minitab 17.3.1). Meat treated with understudy MAP compositions and vacuum packaging reduced total viable count, Pseudomonas count, and total coliform count than control (p<0.05). TVB-N remained below the recommended limit throughout storage except aerobic packaging (p<0.05). Cooking loss (%) was lowered and showed non-significant results (p>0.05) between vacuum packaging and both MAP concentrations. The meat stored in MAP-2 was characterised by higher (p<0.05) visual scores. Whilst MAP-1 showed higher (p<0.05) L^* values and overall acceptability. Sample packaged under aerobic packaging showed significant (p<0.05) results for b^* and thiobarbituric acid reactive substances (TBARS). Meat stored in aerobic packaging showed higher (p<0.05) shear force values. The outcome of this trial may help to promote the application of understudy MAP compositions and rapid detection of microbes by biochemical analysis under local conditions.

• Journal of the Korean Mathematical Society
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• v.46 no.1
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• pp.151-170
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• 2009

Let m be a positive integer. We show that for any given real number ${\alpha}\;{\in}\;[0,\;1]$ and complex number $\mu$ with $|\mu|{\leq}1$ which satisfy $e^{2{\pi}i{\alpha}}{\mu}^m\;{\neq}\;1$, there exists a Blaschke product B of degree 2m + 1 which has a fixed point of multiplier ${\mu}^m$ at the point at infinity such that the restriction of the Blaschke product B on the unit circle is a critical circle map with rotation number $\alpha$. Moreover if the given real number $\alpha$ is irrational of bounded type, then a modified Blaschke product of B is quasiconformally conjugate to some rational function of degree m + 1 which has a fixed point of multiplier ${\mu}^m$ at the point at infinity and a Siegel disk whose boundary is a quasicircle containing its critical point.

• Honam Mathematical Journal
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• v.27 no.3
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• pp.405-419
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• 2005

We present some properties characterizing the Mandelbrot set of quadratic rational maps. Any quadratic rational map is conjugate to either $z^2+c$ or ${\lambda}(z+1/z)+b$. For ${\mid}{\lambda}{\mid}=1$, we find the figure of the Mandelbrot set $M_{\lambda}$, the set of parameters b for which the Julia set of ${\lambda}(z+1/z)+b$ is connected. It is seen to be the whole complex plane if ${\lambda}{\neq}1$, but it is intricate fractal if ${\lambda}=1$. This supplements the work already investigated for the case ${\mid}{\lambda}{\mid}>1$.