• The Journal of the Korea institute of electronic communication sciences
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• 제13권4호
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• pp.685-694
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• 2018

In this paper, we designed and fabricated the frequency mixer, which is the core parts of high frequency head in Ku-band tracking radar. To overcome the problem of single-ended and single-balanced resistive structure, we designed the fine-line structure with balanced mixer, to generate IF signal without distortion in L-band, after receiving the RF signal of the Ku-band. The prototype mixer showed a Noise Figure Max of 6.823dB, Gain of 4.1598~4.676dB and Band Pass of 61MHz in 5 Ku-band samples frequency.

• Journal of Korean society of Dental Hygiene
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• 제13권5호
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• pp.777-786
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• 2013

Objectives : The purpose of the is to investigate the teaching effectiveness of clinical practice instructors and the satisfaction level of dental hygiene majoring students in clinical practice training. Methods : Subjects were second and third grade 480 dental hygiene majoring students in Seoul and Gangwondo. Except 48 incomplete answers, 438 data were analyzed. Questionnaire consisted of general characteristics, teaching of clinical practice instructors, educational content, organization al skills, leadership, learning environment, evaluation skills and clinical practice satisfaction level. Results : 1. A strong positive correlation (r = 0.832) was found between teaching effectiveness and clinical practice satisfaction. A positive correlation more than 0.50 was found between the clinical practice satisfaction, encouragement and support for teaching effectiveness, educational contents, and leadership. 2. There were significant correlations between the encouragement and support (B = 0.209), educational content (B = 0.199), leadership ability (B = 0.257) and ability to create an environment (B = 0.084), evaluation ability (B = 0.083). Conclusions : Teaching effectiveness of the clinical practice instructors had influences on the clinical practice satisfaction. It is necessary to connect clinical practice instructions with satisfaction towards clinical practice to the students.

• Proceedings of the KIEE Conference
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.94-96
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• 2002

The $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$(10wt%) were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature by XRD and SEM. According to the X-ray diffraction patterns of the $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$(10wt%), the ilmenite $MgTiO_3$ and perovskite $SrTiO_3$ structures were coexisted and secondary phase $MgTi_2O_5$ were appeared. Increasing the sintering temperature. the grain size was increased. In the case of $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$(10wt%), dielectric constant, quality factor and temperature coefficient of resonant frequency were $13.52{\sim}18.13,\;32750{\sim}51736GHz$, $-15.78{\sim}25.64ppm/^{\circ}C$, respectively.

• ALGAE
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• 제29권4호
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• pp.355-366
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• 2014

Fucoxanthin is known to be an effective cell proliferation inhibitor with anti-tumor and anti-angiogenic activities. However, there is a lack of data regarding the biological effects of cis isomers of fucoxanthin. To assess the potential therapeutic properties of 9'-cis-(6'R) fucoxanthin (FcA), and 13-cis and 13'-cis-(6'R) fucoxanthin complex (FcB) isolated from Sarggassum siliquastrum, we investigated their inhibitory effects on matrix metalloproteinases (MMPs) in phorbol 12-myristate 13-acetate (PMA)-induced human fibrosarcoma (HT1080) cells. FcA and FcB reduced MMP-2 and MMP-9 protein and mRNA levels, as well as the migration of these cells, in a dose-dependent manner. Additionally, FcA and FcB increased levels of MMPs inhibition factors such as tissue inhibitor of metalloproteinase-1. FcA and FcB significantly inhibited the transcriptional activity of nuclear factor ${\kappa}B$ (NF-${\kappa}B$) and by inhibiting c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases. Our results demonstrate that suppression of the NF-${\kappa}B$, JNK, and p38 signaling pathways may inhibit PMA-induced MMP-2 and MMP-9 activity. Therefore, FcA and FcB may be useful in noninvasive therapeutic strategies against fibrosarcoma metastasis.

• The Korean Journal of Mycology
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• 제17권3호
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• pp.105-113
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• 1989

For selective purification of proteins in Pleurotus cornucopiae, affinity chromatography was performed by p-aminoanilinylsuccinyl-AH-Sepharose 4B gel synthesized by treating p-phenylene diamine with succinyl-AH-Sepharose 4B, which was prepared by treating AH-Sepharose 4B with succinic anhydride. The capacity of p-aminoanilinyl ligand group was 6.1 micromole per milliliter of gel. Total apparent molecular weight of the affinity proteins eluted from the synthesized gel was 167 KD, which were a protein complex of 130 KD and 37 KD. The contents of the nonpolar, polar, positively and/or negatively charged amino acids in the affinity protein were 44.57%, 24.75%, 21.25%, and 9.43%, respectively. Total apparent molecular weight of the affinity proteins eluted from the AH-Sepharose 4B gel was 95.2 KD, which were a protein complex of 61 KD, 31 KD and 3.2 KD. The contents of the nonpolar, positively and/or negatively charged amino acids in the affinity protein by AH-Sepharose 4B gel were 44.05%, 29.13%, and 12.91% respectively.

• Journal of Animal Science and Technology
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• 제47권1호
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• pp.49-56
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• 2005

The Korean styled meat products such as grilled and/or roasted ham(Jikhwagui: J), Bulgogi ham(B), Kimbab ham(K) and sliced roasted ham(DDukgalbi: D) were obtained from different Korean meat processing companies and investigated for their salinity, saccharinity, pH, moisture and fat content, meat color and sensory evaluation. The results obtained were as follows; Percentage of saccharinity in J, B, K and D ranged 7.5 %(13) - 12.7% (J2), 5.3 0/«B2) -7.5 o/«BI), 5.2 0/«K4) - 6.6 o/«KI, K2, KS), and 6.60/«04) - 14.4o/«Dl), respectively. Percentage of salinity in J, B, K and D ranged 2.260/«13)- 2.38 0/«J4), 1.850/«B2) - 2.45 0/«B3), 1.94o/«KI) - 2.40% (K3), and 1.830/«02) - 2.19 o/«Dl), respectively. The pH value of J, B and K were ranged 6.30 - 6.44, 6.266.37 and 6.20 - 6.42, respectively, which are slightly higher than that of D(5.86 - 6.25). Content of average moisture were higher in B(61.0 %), K(59.94%) and J(59.63%) compared to the D(55.93%). In crude fat, B and D were ranged 14-21 %, which are very lower than those of K(59.94%) and J(59.63%). In meat color, $L^*$ value were above 50.0, except D2 and D3. $a^*$ value of B were slightly higher than those of other meat products. Compared to sensory evaluation, the overall acceptability of J is excellent in the range of saccharinity 12.7%, salinity 2.3 %, moisture 61 %, crude fat II - 12%, $L^*$ value 52 - 54, and $a^*$ value 12.3- 12.7. In the case of B, the overall acceptability is excellent in the range of saccharinity 6.6 - 7.5 %, salinity 1.90- 2.45 %, moisture 60 %, crude fat 15 %, $L^*$ value 56, and $a^*$ value 15. In the case of K, the overall acceptability is excellent in the range of saccharinity 6.5 %, salinity 2.4 %, moisture 61 %, crude fat 16%, $L^*$ value 53, and $a^*$ valuce 15. In the case of D, the overall acceptability is excellent in the range of saccharinity 14.0%, salinity 2.1 %, moisture 55%, crude fat 55%, $L^*$ value 50, and $a^*$ value 13.

• The Pure and Applied Mathematics
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• 제13권2호
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• pp.157-165
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• 2006

The notion of regularity in near-ring was generalized by the concept of b-regular and some characterizations of the same was obtained through the substructures viz bi-ideals in near-rings. In this paper, we generalize further and introduce tile notion of weakly b-regular near-rings and obtain a characterization of tile same.

• Journal of Environmental Health Sciences
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• 제13권1호
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• pp.41-46
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• 1987

The purpose of this experiment was to investigate the leisons of mice produced by intraperitoneal injection of rubratoxin B. But the mice injected 3$\mu$g and 5$\mu$g of rubratoxin B showed retardation of growth, and slight swelling of kidneys. The hemorrhage in the renal cortex tubular dilation containing the desquamated epithelial cells, and adhesion of Bowman's spaces by proliferation of endothelial cells were histopathoglogically characterized in the kidneys of mice.

• Microbiology and Biotechnology Letters
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• 제22권5호
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• pp.491-494
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• 1994

Antibiotic HS-2 was purified from the culture broth of Streptomyces plicatosporus which was isolated from soil, by solvent extraction, silica gel column chromatography and gel filtration. Through the analysis of UV, $^{1}$H-NMR, $^{13}$C-NMR spectrum, HS-2 was identified as rubiginone B$_{2}$. It was confirmed that HS-2 enhanced the cytotoxicity of colchicine against multidrug-resistant tumor cells.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제13권3호
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• pp.217-224
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• 2009

In this paper we present an approximation method of quadric surface using quartic spline. Our method is based on the approximation of quadratic rational B$\acute{e}$zier patch using quartic B$\acute{e}$zier patch. We show that our approximation method yields $G^1$ (tangent plane) continuous quartic spline surface. We illustrate our results by the approximation of helicoid-like surface.