• Information and Communications Magazine
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• v.24 no.11
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• pp.5-13
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• 2007

광대역 무선 접속 표준을 관장하는 IEEE 802.16 워킹 그룹은 IEEE 802.16 표준을 2004년에 발표하였으며 이 IEEE 802.16 표준안에는 현재 WiMAX(Worldwide Interoperability for Microwave Access)라 불리는 고정 및 저속 이동 접속에 대한 광대역 무선 통신 지원 기술이 포함되어 있다. 특히 여러 기술 중 보안 관점에서 IEEE 802.16 표준은 MAC 계층 안에 PKM(Privacy Key Management)라고 불리는 Security Sub-layer를 가지고 있다. PKM은 PKMv1과 PKMv2로 구분되며, 먼저 PKMv1은 기본적인 인증 및 기밀성 기능을 제공하고 IEEE 802.16 표준에 기본적으로 적용되어있다. 하지만, IEEE 802.16 표준 이후 많은 연구들이 PKMv1의 보안성에 대하여 의문을 제기하였고 이에 따라 IEEE 802.16 표준안의 확장 개선안으로서 완전한 이동성을 바탕으로 하는 2005년 발표된 IEEE 802.16e 표준안에서는 향상된 보안 기능을 제공하는 PKMv2를 제공하며 기존 표준안의 부족한 점을 보완하기 위하여 시도하였다. 이러한 PKMv2는 EAP(Extensible Authentication Protocol) 인증, AES(Advanced Encryption Standard) 기반 기밀성 제공 알고리즘, CMAC/HMAC(Cipher/Hashed Message Authentication Code)을 사용한 메시지 인증 기능 제공 등 보다 다양한 보안 기능을 제공하였다. 그러나 IEEE 802.16e 표준안의 보안 기능은 SS(Subscriber Station)과 BS(Base Station)간의 통신구간 보안에 초점을 맞추어서 네트워크 도메인간의 보안 문제나 핸드오버시 보안과 같은 네트워크 구조적 보안 취약성을 여전히 가지고 있다. 하지만 표준안에서 정의하고 있는 SS와 BS 구간 보안 역시 완전한 솔루션을 제시하고 있지는 않다. 본 논문에서는 이러한 취약성을 고찰하고 그에 따른 대응방안을 제시하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.966-968
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• 2009

In IEEE 802.16 system, it is important to allocate resources appropriately in order to the efficient utilization of resources among a variety of real-time and non real-time packets. although a lot of the real-time and non real-time packet scheduling schemes in OFDMA system have been proposed, it need to be modified to apply to IEEE 802.16 system. Since IEEE 802.16 supports five kinds of service classes, it is important to take QoS constraints of these classes into consideration. In this paper, we propose a efficient scheduling scheme to support various services by considering the QoS constraints of each classes.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.149-157
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• 2023

Phytoplasmas were discovered in diseased Elaeocarpus sylvestris trees growing on Jeju Island that showed symptoms of yellowing and darkening in the leaves. Leaf samples from 14 symptomatic plants in Jeju-si and Seogwipo-si were collected and phytoplasma 16S rRNA was successfully amplified by nested polymerase chain reaction using universal primers. The sequence analysis detected two phytoplasmas, which showed 99.5% identity to 'Candidatus Phytoplasma asteris' and 'Ca. P. malaysianum' affiliated to 16SrI and 16SrXXXII groups, respectively. Through polymerase chain reaction-restriction fragment length polymorphism (RFLP) analyses using the AfaI (RsaI) restriction enzyme, the presence of two phytoplasmas strains as well as cases of mixed infection of these strains was detected. In a virtual RFLP analysis with 17 restriction enzymes, the 16S rRNA sequence of the 'Ca. P. asteris' strain was found to match the pattern of the 16SrI-B subgroup. In addition, the phytoplasmas in the mixed-infection cases could be distinguished using specific primer sets. In conclusion, this study confirmed mixed infection of two phytoplasmas in one E. sylvestris plant, and also the presence of two phytoplasmas (of the 16SrI and 16SrXXXII groups) in Jeju Island (Republic of Korea).

• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.4
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• pp.1-18
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• 2009

Purpose: This study was performed to elucidate the inhibitory effect of Mibaeksan (MB) on melanin synthesis in B16F10 mouse melanoma cell. Methods: To demonstrate the inhibitory effects of MB on melanin synthesis, we measured the amount of released and produced melanin in B16F10 melanoma cell. Also, we evaluated tyrosinase-activity in vitro as well as in B16F10 melanoma cell. And to investigate the action mechanism, we assessed the gene expression of tyrosinase, TRP-1, TRP-2, MMP-2, PKA, $PKC{\beta}$, ERK-1 ERK-2, AKT-1 and MITF in B16F10 melanoma cells. Results: 1. MB decreased the release and production of melanin in B16F10 melanoma cells. 2. MB decreased tyrosinase activity in vitro and in B16F10 melanoma cells. 3. MB decreased the expression of tyrosinase, TRP-1, TRP-2, PKA, $PKC{\beta}$ and MMP-2 in B16F10 melanoma cells. 4. MB increased the expression of ERK-1, ERK-2 and AKT-1 in B16F10 melanoma cells. 5. MB decreased the expression of MITF in B16F10 melanoma cells. Conclusion: From these results, it may be concluded that MB has the antimelanogenetic effects.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.1
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• pp.48-58
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• 2013

The results of this research to study forms, structure, changes, symbolic meanings of 16 Hahoe sceneries through analyses of "Hahwaesipyukgyeong" and "Hahwaenakgangsanghaildaedo" are as belows. The coherence of headword is not discovered in 16 Hahoe sceneries, but based on various variables and sense dependence, endemicity with original natural scenes, human's life and phenomena of riverside village are spread in 3km viewing areas within 200m from Gyeonamjeongsa(謙巖精舍) and Okyeonjeongsa(玉淵精舍). As the viewing points of Gyeonam and Okyeonjeongsa are symmetrically facing and separately independent, while viewing angles do not intersect at Wonjijeongsa (遠志精舍) and Binyeonjeongsa(賓淵精舍) because of Buyongdae(芙蓉臺), and crating each independent viewing area, we can see 16 Hahoe sceneries are perfect views by supplementing Gyeonam and Okyeon Jeongsa, as well as points of views from Wonji and Binyeonjeongsa. Meanwhile, as the view point of 16 Hahoe sceneries, Gyeomam, Okyeon, Binyeon, and Wonji Jeongsa are clearly described, and 12 natural sceneries, which are Hwasan(花山), Ipam(立巖), Maam(馬巖), Jando(棧道), Bangi(盤磯), Hoengju(橫舟), and Honggyo(虹橋), among landscape elements of 16 Hahoe sceneries that can be expressed on canvas in the Haoedo are realistically described, there is high possibility that Haoedo is the 'Mental Stroll about Nature(臥遊) of 16 Hahoe sceneries. The belted forest surrounding the village in the painting is assumed to be an erosion control forest, and considering row-expressed trees, the south belted forest may be a different broad-leaved forest from current Mansongjeong(萬松亭) pine forest. In 16 Hahoe sceneries, there is Neo-confucianism tendency, which connects the nature and human life, and moreover prioritize human life than the nature. Especially as seen in the 'Choljae(拙齋)', the pen name of 16 Hahoe sceneries' author park, the 16 Hahoe scenery poet suggests 'Beauty of Jolbak(拙撲美)' based on the simple life that upright classical scholars pursued as the basic emotion. The thinking system shown in the poet is interpreted as Neo-confucianism category including one's sense and emotion depended on natural features or phenomena. Ultimately, 16 Hahoe sceneries are landscape that reflects moral world views of Confucianism scholars who wanted to express ideal thoughts based on natural features and phenomena in reality at Jeongsa in Buyongdae and Hahoe Village.

• Journal of Life Science
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• v.22 no.2
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• pp.184-191
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• 2012

The purpose of this study was to examine the effect of 16 weeks of resistance training on the fatigue factor, muscle soreness, oxidative stress, and myokine in elite weightlifters. A total of 10 subjects (six male, four female) participated in this study. The results were compared according to baseline, 8 weeks, and 16 weeks. Ammonia and Pi were increased through 16 weeks of resistance training, but this result was not significant. CK was significantly (p<0.05) increased at 8 weeks and 16 weeks compared to baseline, while LDH was significantly (p<0.05) increased at 8 weeks compared to baseline. The MDA of the oxidative stress factor was significantly (p<0.05) increased at 8 weeks compared to baseline and 16 weeks, and TAS of the antioxidant factor was significantly (p<0.05) increased at 8 weeks compared to baseline. The IL-15 of the myokine was significantly (p<0.05) increased at baseline compared to 8 weeks and 16 weeks. In conclusion, 16 weeks of high-intensity resistance training may have a positive effect on peripheral fatigue factors, muscle soreness, oxidative stress, and myokine in elite weightlifters.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.1
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• pp.110-121
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• 2016

Link-16 is a representative TDL operated by US air force and NATO and supports structure of Multi-net. Under Multi-net, military operation can be conducted effectively since terminal nodes in Link-16 hop over total frequency band simultaneously. As air traffic is rapidly increasing, new aeronautical system is introduced or existing system should be expanded to accommodate increasing air traffic and frequency band assigned for operating this system is scarce. It is scheduled to implement frequency remapping to solve frequency scarcity. With limited frequency band for operating Link-16, as frequency remapping is implemented, degradation of Multi-net performance can happen since multiple access interference in Link-16 is increasing so it is difficult to conduct multiple military operations. Thus, Group-based frequency hopping scheme is proposed to solve this problem. We verified the performance of the proposed scheme is improved.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.471-476
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• 2000

Objective : p16/INK4a, a kind of tumor suppressor genes, encodes a specific inhibitor of the cyclin D-dependent kinases CDK4 and CDK6. This prevents the association of CDK4 with cyclin D1, and subsequently inhibits phosphorylation of retinoblastoma tumor suppressor protein(pRb), thus preventing exit from the G1 phase. According to previous reports, over 50% of glioma tissue and 80% of glioma cell lines have been demonstrated inactivation of p16/INK4a gene. The purpose of this study was to determine whether recombinant adenovirus-p16 virus is a suitable candidate for gene replacement therapy in cases of glioma. Methods : Three human glioma cell lines(U251MG, U87MG and U373MG) that express mutant p16 protein were used. Replication-deficient adenovirus was utilized as an expression vector to transfer exogenous p16 cDNA into the cells ; control cells were infected with the Ad-${\beta}$-gal expressing ${\beta}$-galactosidase. To monitor gene transfer and the expression of exogenous genes, we used Western Blotting analysis. Flow cytometry studies of cellular DNA content were performed to determine the cell cycle phenotype of the glioma cells before and after treatment. Results : We showed here that restoration of p16/INK4a expression in p16 negative U87MG, U251MG and partially deleted U373MG by Ad-CMV-p16 induced growth suppression in vitro. Flow cytometric study revealed that Ad-CMV-p16 infected U87MG cells were arrested during the G0-G1 phase of the cell cycle. Expression of p16 transferred by Ad-CMV-p16 in glioma cells was highly efficient and maintained for more than seven days. Conclusions : Our results suggest that Ad-CMV-p16 gene therapy strategy is potentially useful and warrants further clinical investigation for the treatment of gliomas.

• International Journal of Oral Biology
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• v.32 no.3
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• pp.93-101
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• 2007

Cell behavior of the transformed cells is known to affect by interaction with extracellular matrix (ECM) proteins and integrin. To investigate the alterations of both integrin expression and cell-matrix interaction during neoplastic conversion of human oral kerationcytes, we studied expression levels of integrin subunits by flow cytometry and cellular responses to the ECM proteins in normal human oral keratinocytes (NHOKs), HPV-immortalized HOK-16B line, and three oral cancer cell lines established from HOK-16B line, CTHOK-16B-BaP, CTHOK-16B-DMBA, and CTHOK-16B-Dexa lines. The expression levels of ${\alpha}\;and\;{\beta}$ integrin subunits were shown decreased tendency in human oral keratinocytes undergoing immortalization and tumorigenic transformation except CTHOK-16B-DMBA line tested. Although ${\alpha}v{\beta}6$ integrin is known to be highly expressed in squamous cell carcinomas, and the altered integrin expression is suspected to be associated with cellular carcinogenesis, ${\alpha}v$ integrin subunit and ${\alpha}v{\beta}6$ integrin did not express in oral cancer cell lines tested. Cell behavior to the ECM proteins in HOK-16B line was generally similar to that of exponentially proliferating NHOKs. The adhesion activity profiles of type I collagen were very similar to that of its laminin counterparts, but fibronectin showed minimal adhesion activity under our conditions compared to the BSA control. The ability of the CTHOK-16B-BaP line to spread upon type I collagen and laminin markedly decreased, but migration was notably increased on type I collagen. In contrast, CTHOK-16B-DMBA and CTHOK-16B-Dexa lines spread less but migrated more upon type I collagen than immortalized HOK-16B line. These data indicate that downregulation of integrin subunits causes the changes of cellular responses to the ECM proteins during neoplastic conversion of human oral keratinocytes, and that cellular responses to the ECM proteins in oral cancer cell lines established by exposing different carcinogens are variable according to chemical carcinogens treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.141-142
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• 2006

Thermoelectric properties and microstructures of $Sr_{8-x}Ba_xGA_{16}Ge_{30}$ alloys fabricated by the arc-melting method were investigated. The alloys with the nominal composition of $Sr_8Ga_{16}Ge_{30}$ and $Ba_8Ga_{16}Ge_{30}$ were the single-phase alloys, while those of $Sr_4Ba_4Ga_{16}Ge_{30}$ and $Sr_2Ba_6Ga_{16}Ge_{30}$ were two-phases alloys. Electrical resistivity and the Seebeck coefficient for both two-phases alloys were higher in magnitude than those of the single-phase alloys between room temperature and 873K The thermal conductivities for both two-phase alloys were reduced with respect to those of the single-phase alloys in the whole temperature range. The maximum values of ZT for $Sr_4Ba_4Ga_{16}Ge_{30}$ and $Sr_2Ba_6Ga_{16}Ge_{30}$ were achieved with the values of 0.69 at 753K and 0.51 at 754K, respectively, while those of $Sr_8Ga_{16}Ge_{30}$ and $Ba_8Ga_{16}Ge_{30}$ were 0.86 at 758K and 0.76 at 943K, respectively.