• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.107-114
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• 2009

In this paper, high efficiency amplifier configuration is proposed using the reconfigurable power divider. In order to enhance average efficiency of linear power amplifiers for wireless communication, it is required to increase efficiency in low output power region. The proposed power divider operates in two modes, high power mode and low power mode, according to output power. In each mode, it allows impedance matches and low loss, which is made possible by employing two $\lambda/4$ coupled lines and two switches. The fabricated power divider shows the return loss ($S_{11}$) and insertion loss ($S_{21}$) of -16.49 dB and -0.83 dB, respectively, in low power mode. In high power mode, the measured return loss ($S_{11}$) and insertion loss ($S_{31}$) are -16.28 dB and -0.73 dB, respectively. This result successfully demonstrates the reconfigurability of the proposed power divider.

• KSBB Journal
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• v.23 no.3
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• pp.251-256
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• 2008

The aim of this work was to investigate the fibrinolytic activity and characterization of Bacillus licheniformis HK-12, which produces the fibrinolytic enzyme excreted from naturally fermented Chungkook-Jang. Initially, the physiological and biochemical characteristics of strain HK-12 was examined. Both physiological analysis using BIOLOG system and phylogenetic analysis using 16S rRNA sequencing were performed to identify the strain, and the strain could be assigned to Bacillus licheniformis, designated as B. lichenformis HK-12, and registered in GenBank as [EU288193]. Phylogenetic analysis of B. licheniformis HK-12 was plotted based on 16S rRNA sequence comparisons. During the incubation period of B. licheniformis HK-12, the changes of bacterial growth, fibrinolytic activity, and pH were monitored. As the results, after 36 hours of incubation, the maximum fibinolytic activity was about 2.25 times than that of plasmin used as standard. Optimal conditions on the growth of B. licheniformis HK-12 associated with the fibrinolytic activity was initial pH 7.0 and 40$^{\circ}C$, respectively.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.291-298
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• 2016

The aim of the study was to investigate the diagnostic value of the color Doppler twinkling artifact in disease of urinary system. The intensity of twinkling artifact(TA) with color Doppler was classified into 3 levels, 0(non-TA) to 3(distinct TA). In the in vitro study, acorn jelly with various materials on top was examined using color Doppler at B-mode sonography in a water bath for TA. 31 patients with diagnosis of urinary calculi(renal stones 16, urinary stones 15) based on B-mode sonography were studied in vivo for TA. The materials with rough surfaces such as salt, screw and cubics at B-mode sonography with color Doppler contributed to causing TA. At B-mode sonography without color Doppler 37% of renal stones and 60% of ureter stones were detected. but at B-mode sonography with color Doppler TA was demonstrated for all cases. Superficial roughness of materials affected occurrence of TA at B-mode sonography with color Doppler. Therefore, TA at B-mode sonography without color Doppler could play a role in confident diagnosis of the disease of urinary system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1326-1330
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• 2012

This study was conducted to develop a loop-mediated isothermal amplification (LAMP) method for the detection of Clostridium difficile. The tested target gene was 16S ribosomal RNA. Five different LAMP primer sets were designed, and LAMP was performed. All primer sets targeting the 16S rRNA gene (BIP, FIP, B3, F3, LF, PF) were determined as positive in tcdA-positive, tcdB-postive ($A^+B^+$) and tcdA-negative, tcdB-negative ($A^-B^-$) Clostridium difficile strains. As the LAMP reaction took less than 80 min and did not require expensive machine such as thermocycler, it can be used as a rapid and simple detection method for foodborne pathogens.

• The Korea Journal of Herbology
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• v.27 no.4
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• pp.73-80
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• 2012

Objectives : Under normal condition melanin protects the skin from extracellular stimuli including ultraviolet (UV)-induced oxidative skin damages, but excess production and accumulation of melanin can induce hyperpigmentation causing esthetic problems. Therefore, in this study we tried to search for natural skin whitening materials from marine natural resources. Methods : Water and ethanol extracts of marine natural resources were prepared from Porphyra thalli (PT), Laminariae thallus (LT), Ostreae concha (OC), Sargassum thallus (ST), Undaria thallus (UT), Codium thalli (CT), Enteromorpha thalli (ET), Syngnathoides biaculeatus (SB), and Hippocampus coronatus (Hc). Their effects against UVB and ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH)-induced melanogenesis were investigated based on melanin formation in B16 mouse melanoma cells. The mRNA and protein expression of enzymes involved in the melanogenic process were further examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. Results : Water extract of Ostreae concha (OCW/E) effectively inhibited UVB and ${\alpha}$-MSH-induced melanin production in B16 melanocytes, which seemed to be mediated by inhibition of mRNA expression of tyrosinase and tyrosinase-related protein 1 (TRP-1). In another experiment, ethanol extracts from Porphyra thalli (PTE/E), Laminariae thallus (LTE/E), Sargassum thallus (STE/E), Undaria thallus (UTE/E), Codium thalli (CTE/E), Syngnathoides biaculeatus (SBE/E), and Hippocampus coronatus (HcE/E) significantly suppressed UVB and ${\alpha}$-MSH-induced melanin formation. Furthermore, ethylacetate fraction isolated form LTE/E (LTE/EEt) decreased UVB and ${\alpha}$-MSH-elevated extracellular melanin levels via inhibition of tyrosinase protein expression. Conclutions : These results suggest that marine natural resources such as Porphyra thalli, Laminariae thallus, Ostreae concha, Sargassum thallus, Undaria thallus, Codium thalli, Syngnathoides biaculeatus and Hippocampus coronatus have anti-melanogenic effects, thereby exhibiting high potentials to be utilized as one of the ingredients for the development of new whitening functional cosmetics.

• Journal of Pharmacopuncture
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• v.10 no.1 s.22
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• pp.85-100
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• 2007

Objectives : This research was executed to verify antitumor effect and protective effect on doxorubicin(Doxo)-induced toxicity of Cultivated Wild Ginseng(CWG) and synergic effect of CWG with Doxo in B16/F10 melanomas-bearing C57BL/6 mice. Methods : To evaluate protective effect on doxorubicin(Doxo)-induced toxicity and enhancing effect on the antitumor activity of Doxo, CWG water extract(0.5 ml) was intraperitoneally injected for 10 days, in combination with intraperitoneal injection of Doxo(4 mg/kg) on days 12, 16, 19, to mice subcutaneously inoculated with $2{\times}10^6/ml$ B16/F10 melanoma cells. In order to investigate antitumor effect of CWG, CWG water extract(0.5 ml) was intraperitoneally injected for 10 days to mice subcutaneously inoculated with $2{\times}10^6/ml$ B16/F10 melanoma cells. Results : The body weights of melanoma-bearing mice increased following B16/F10 cells inoculation. In contrast, such an increase in body weights was significantly attenuated by Doxo administration. Whereas CWG inhibits the decrease in body weights induced by Doxo. The tumor volume and tumor weights of melanomas-bearing mice dramatically increased following B16/F10 cells inoculation, In contrast, such an increase in tumor volume and tumor weights were significantly attenuated by Doxo or CWG administration. But the synergic effect of CWG with Doxo was not observed. The reduction of cellularity of seminiferous epithelia, level of spermatogonium and spermatid induced by Doxo was recovered by CWG administration. BrdU labeling index of spermatogonium was remarkably decreased in Doxo group but was no change in CWG group. Whereas the incidence and intensity of BrdU labelled spermatocytes and spermatids were increased by CWG administration than those of Doxo group. Conclusions : The obtained results suggest that CWG have antitumor effect and protective effect on doxo-induced testicular toxicity. This effect might be mediated through the supplementation of vital energy.

• Korean Journal of Ichthyology
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• v.18 no.2
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• pp.78-86
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• 2006

We examined the genetic diversity in intra-populations of Korean shiner, Coreoleuciscus splendidus, in six major rivers (Bukhan, Namhan, Geum, Osipcheon, Nakdong and Seomjin river) of Korea based on two different mitochondrial genes, the mitochondrial cytochrome b and the 16S rRNA. Analysis of sequence variation in a 657-bp segment of the mitochondrial cytochrome b gene revealed deep divergence among populations (98.2~99.9%) and high genetic diversity from geographically isolated populations. Intra-specific variation in this 697-bp segment of the 16S rRNA gene sequences was very low and nearly identical. Six isolate populations of C. splendidus showed a high similarity (97.7%~99.7%). This result may be indicative of a complex history of connection and isolation of the rivers in the Korea peninsula.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.111-115
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• 2006

스케일러블 비디오 코딩(SVC, Scalable Video Coding)은 MPEG(Moving Picture Expert Group)과 VCEG (Video Coding Expert Group)의 JVT(Joint VIdeo Team)에 의해 현재 표준화 되고 있는 새로운 압축 표준 기술이며 시간, 공간 및 화질의 스케일러빌리티를 지원하기 위해 계층 구조를 가지고 있다. 특히 시간적 스케일러빌리티를 위해 계층적 B-픽처 구조를 채택하고 있다. 스케일러블 비디오 코딩의 기본 계층은 H.264|AVC와 호환적이므로, 모션 예측과 모드 결정과정에서 $16{\times}16,\;16{\times}8,\;8{\times}16,\;8{\times}8,\;8{\times}4,\;4{\times}8$ 그리고 $4{\times}4$와 같은 7개의 서로 다른 크기를 갖는 블록을 사용한다. 스케일러블 비디오 코딩에서 사용되고있는 계층적 B-픽처 구조는 키 픽처인 I와 P 픽처를 제외하고는 한 GOP (Group of Picture)내에서 모두 B-픽처를 사용하므로 H.264|AVC와 비교했을 때 연산량 증가와 함께 부호화 지연도 급격히 증가한다. B-픽처는 양방향 모션 벡터인 LIST0와 LIST1을 사용하고 양방향 모두에서 다중 참조 픽처를 사용하기 때문이다. 본 논문에서는 통계적 가선 검증을 이용하여 스케일러블 비디오 부호화에 적용 가능한 고속 프레임간 모드 결정 알고리듬 대해 소개한다. 제안된 방법은 $16{\times}16$ 매크로 블록과 $8{\times}8$ 서브 매크로 블록에 통계적 가설 감증 기법을 적용하여 실행되며, 현재 블록과 복원된 참조 블록간의 픽셀 값을 비교하여 RD(Rate Distortion) 최적화 기반 모드 결정을 빨리 완료함으로써 고속 프레임간 모드 결정을 가능하게 한다. 제안된 방법은 프레임 간 모드 결정을 고속화함으로써 스케일러블 비디오 부호화기의 연산량과 복잡도를 최대 57%감소시킨다. 그러나 연산량 감소에 따른 비트율의 증가나 화질의 열화는 최대 1.74% 비트율 증가 및 0.08dB PSNR 감소로 무시할 정도로 작다.

• The Journal of Korean Medicine
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• v.16 no.2 s.30
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• pp.365-385
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• 1995

In order to prove the antitumor effect of Wekyungtang(WKT) that was originated in Bigeubchunkeumyobang(備急千金要方), Wekyungtang with Houttuyniae Herba(WKT-I) and Wekyungtang with Oldenlandiae diffusae Herba(WKT-II) experimentally, the studies were done, We evaluated the cytotoxic activity against B16- Fo as well as the synergistic effects with anticancer drugs such as cyclophophamide (CPM), cisplatin(CPT) and 5-fluorouracil (5-FU) in vitro and measured body weight, survival time, hematological changes, changes of tissues in G57BL／6 implanted with B16-Fo. The results were obtained as follows: 1. In vitro cytotoxic effect against B16-Fo was shown in all groups as compared with control group, but the concentrations showing inhibitory growth rate below 55% of control was recognized in all concentrations of Wekyungtang(WKT) against B16-Fo and also concentration of $10^4$g／ml above in all group with cyclophophamide (CPM), concentration of $10^3$g／ml in Wekyungtang(WKT-l) with cisplatin(CPT) in synergistic effect, 2. In vivo body and tumor weight were significantly suppressed in all groups as compared with control group 3. The number of platelet, WBC, RBC were significantly increased in all groups, platelet aggregation was significantly increased in WKT-I and WKT-II as compared with control group. 4. In changes of tissues heavy infiltration oh cancer was shown in portal vein, pulmonary tissue, vein, peribronchiole, aveoli, while WKT-I was effective in antihepatic metastasis and WKT-II in pulmonary matastasis. From above results it was concluded that wekyungtang(WKT), wekyungtang with Houttuyniae Herba(WKT-I) and wekyungtang with Oldenlandiae diffusae Herba(WKT -II) had antitumor effect, and also wekyungtang combined with Houttuyniae Herba or Oldenlandiae diffusae Herba were more effective than wekyungtang only and also cyclophophamide (CPM), cisplatin(CPT) showed the more synergistic effect which suggests the necessity of continuous study on the mechanism of antitumor action of Houttuyniae Herba or Oldenlandiae diffusae Herba.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.16 no.3
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• pp.129-144
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• 2003

Recently many efforts were focused to understand the mechanical insights of melanogenesis to develop the agents for hyper-pigmentation and hypo-pigmentation. In the melanin biosynthetic pathway, tyrosinase is the rate limiting enzyme, and ${\alpha}$-melanocyte stimulating hormone(MSH) or cAMP-elevating agents stimulate melanogenesis and enhance the melanin synthesis and the tyrosinase activity. The author has analyzed the effects of Rhizoma Bletillae on the basal melanogenic activities of B16／F10 mouse melanoma cells, and on the ${\alpha}$-MSH or forskolin-induced melanogenesis. Rhizoma Bletillae alone markedly suppressed melanin content and tyrosinase activity in a dose-dependent manner. Pretreatment of the cells with Rhizoma Bletillae also suppressed the increase of ${\alpha}$-MSH (100 nM) or forskolin (20 ${\mu}M$)-induced melanin content and tyrosinase activity. The decrease in the tyrosinase activity was paralled by a decrease in the abundance of tyrosinase protein and tyrosinase promoter activity. Pretreatment of the cells with Rhizoma Bletillae also inhibited the increase of forskolin(20${\mu}M$) induced the amount of tyrosinase protein and tyrosinase promoter activity. The results of DOPA staining revealed that pretreatment of the cells with Rhizoma Bletillae showed less intensity than B16 melanoma cells stimulated with ${\alpha}$-MSH or forskolin. These results suggest that Rhizoma Bletillae inhibits melanogenesis and abrogates ${\alpha}$-MSH and cAMP-induced melanogenesis in B16 melanoma cells.