• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.9 s.112
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• pp.860-865
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• 2006

In this paper, a novel tunable inter-digital capacitor using dielectric tunable $Bi_2O_3-ZnO-Nb_2O_5(BZN)$ pyrochlore thin films is proposed. In order to improve the tunability and reduce DC bias voltage using the fringing electric field, the electrodes of the inter-digital capacitor are embedded in the thin film. Designed results using a 2.5 D simulator show that the tunability of the proposed inter-digital capacitor improves by 10 %, compared to the conventional inter-digital capacitor. The proposed IDC, which is based on the simulation results, was fabricated, using the BZN thin film deposited by a reactive RF magnetron sputtering on the on the silicon substrate. The fabricated inter-digital capacitor shows the maximum tunability of 50 % at 5.8 GHz and 18 V DC applied.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.530-535
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• 2021

In this paper, the design method for a chipless RFID tag using ELC resonators is proposed. A four-bit chipless RFID tag is designed in a two by two array configuration using three ELC resonators with different resonant peak frequencies and one compact IDC resonator. The resonant peak frequency of the bistatic RCS for the IDC resonator is 3.125 GHz, whereas those of the three ELC resonators are adjusted to be at 4.225 GHz, 4.825 GHz, and 5.240 GHz, respectively, by using the gap between the capacitor-shaped strips in the ELC resonator. The spacing between the resonators is 1 mm. Proposed four-bit tag is fabricated on an RF-301 substrate with dimensions of 50 mm×20 mm and a thickness of 0.8 mm. It is observed from experiment results that the resonant peak frequencies of the fabricated four-bit chipless RFID tag are 3.290 GHz, 4.295 GHz, 4.835 GHz, and 5.230 GHz, respectively, which is similar to the simulation results with errors in the range between -2.3% and 0.2%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.179-179
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• 2009

This is for the electrical characterization by IDC pattern using BST$(Ba_{0.5}Sr_{0.5}TiO_3)$ thin film. BST materials had been chosen for high frequency applications due to it's high permitivity and tunability. The BST thin films have been deposited on $Al_2O_3$ Substrates by Nd-YAG pulsed laser deposition with a 355nm wavelength at $700\;^{\circ}C$. The post deposition annealing at $750^{\circ}C$ in flowing $O_2$ atmosphere for 1 hours. The capacitance of IDC patterns have been measured from 1 to 10 GHz as a function of electric field ($\pm40$ KV/cm) at room temperature using inter-digital Au electrodes deposited on top of BST. The IDC patterns have three type of fingers number. For the 10 pairs finger was the best capacitance onto $Al_2O_3$ substrate. The capacitance was 0.9pF. Also Dielectric constant was been 351 at 100 mTorr and annealing temperature $750^{\circ}C$ for 1 hour. The loss tangent was been 0.00531.

• Journal of Sensor Science and Technology
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• v.27 no.2
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• pp.69-75
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• 2018

In this study, we propose a multichannel interdigitated capacitor (IDC) sensor for detecting the bitterness of coffee. The operating principle of the device is based on the variation in capacitance of a sensing membrane in contact with a bitter solution. Four solvatochromic dyes, namely, Nile red, Reichardt's dye, auramine-O, and rhodamine-B, were mixed with polyvinylchloride (PVC) and N,N-dimethylacetamide (DMAC), to create four different types of bitter-sensitive solutions. These solutions were then individually inserted into four interdigitated electrodes (IDEs) using a spin coater, to prepare four distinct IDC sensors. The sensors are capable of detecting bitterness-inducing chemical compounds in any solution, at concentrations of approximately $1{\mu}M$ to 1 M. The sensitivity of the IDC bitterness sensor containing the Reichardt's dye sensing-membrane was approximately 1.58 nF/decade. The multichannel sensor has a response time of approximately 6 s, and an approximate recovery time of 5 s. The proposed sensor offers a stable sensing response and linear sensing performance over a wide measurement range, with a correlation coefficient ($R^2$) of approximately 0.972.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3757-3761
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• 2014

Purpose: The aim of this study was to investigate the prognostic significance of the CD56+NK-TIL count in infiltrating ductal carcinoma (IDC) of breast. Material and Methods: Immunohistochemistry (IHC) was performed using antibodies specific for CD56 on formalin-fixed and paraffin-embedded tissue sections of 175 infiltrating ductal carcinomas (IDC) of breast. Distribution of intratumoral and stromal CD56+NK-TILs was assessed semi-quantitatively. Results: A low intratumoral CD56+count showed significant and inverse associations with tumor grade, stage, and lymph node status, whereas it had significant and direct association with response to treatment indicating good prognosis. These patients had better survival (${\chi}^2$=4.80, p<0.05) and 0.52 fold lower death rate (HR=0.52, 95% CI=0.28-0.93) as compared to patients with high CD56+ intratumoral count. The association of survival was insignificant with low CD56 stromal count as compared to high CD56 stromal count (${\chi}^2$=1.60, p>0.05). Conclusion: To conclude, although NK-TIL count appeared as a significant predictor of prognosis, it alone may not be sufficient for predicting the outcome considering the fact that there exists a crosstalk between NK-TILs and the other immune infiltrating TILs.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.823-829
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• 2015

The aim of the present study was to investigate the expression of the transcription factor Ki-67, ER, PR, Her2/neu, p21, EGFR, and TOP II-${\alpha}$ in the tumor tissue of patients with invasive ductal carcinoma(IDC); in addition, we examined correlations between these markers. Two hundred and sixteen IDC patients, who were not previously been treated with chemo- or radiotherapy, were included in the study. All tumors were grade I-III. Expression of molecular markers was determined by immunohistochemical analysis on paraffin-embedded tissue sections. Follow-up data were collected for 3 months to 10 years and analyzed for tumor recurrence, survival time, and prognostic risk factors. We determined Ki-67 expression correlates with the expression of ER, PR, HER-2, EGFR, and TOP-${\alpha}$, as well as lymph node involvement, high tumor grade, lymphovascular invasion, high tumor stage, and high TNM stage in IDC. Positive Ki-67 expression was a risk factor for rapid tumor recurrence and may help tumor progression, leading to poor prognosis in IDC. Ki-67 was directly correlated with EGFR, TOP II-${\alpha}$, lymph node involvement, high tumor grade, lymphovascular invasion, high tumor stage, and high TNM stage in the hormone receptor subtypes of breast cancer. In triple negative breast cancer, Ki-67 correlated with TOP II-${\alpha}$. Expression of Ki-67 correlated with that of ER, PR, HER-2, EGFR, TOP II-${\alpha}$, and p21. In addition, the biomarker Ki-67 has a role as a prognostic factor and indicates a poor prognosis in IDC.

• Electric Engineers Magazine
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• s.324
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• pp.33-35
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• 2009

• Korea Information Processing Society Review
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• v.9 no.2
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• pp.38-42
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• 2002

• Journal of Power Electronics
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• v.12 no.1
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• pp.157-163
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• 2012

Internet Data Centers (IDCs), which are essential facilities in the modern IT industry, typically have scores of MW of concentrated electric loads. The provision of an Uninterruptible Power Supply (UPS) is necessary for the power feed system of IDCs owing to the need for stable power. Thus, conventional IDC AC power feed systems have three cascaded power conversion stages, (AC-DC), (DC-AC), and (AC-DC), resulting in a very low conversion efficiency. In comparison, DC power feed systems require only a single power conversion stage (AC-DC) to supply AC main power to DC server loads, resulting in comparatively high conversion efficiency and reliability [4-11]. This paper compares the efficiencies of a 220V AC power feed system with those of a 300V DC power feed system under equal load conditions, as established by the Mok-Dong IDC of Korea Telecom Co. Ltd. (KT). Experimental results show that the total operation efficiency of the 300V DC power feed system is approximately 15% higher than that of the 220V AC power feed system.

• Korean Journal of Pharmacognosy
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• v.48 no.1
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• pp.1-4
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• 2017

Four polyketides, tyrosol (1), (3R,4R)-(-)-4-hydroxymellein (2), (3R,4S)-(-)-4-hydroxymellein (3), and 1-phenyl-1,2-ethanediol (4) were isolated from organic extracts of cultures of an endophytic fungus Arthrinium sp. (JS420) isolated from stem of a halophyte Suaeda japonica Makico. Chemical structures of the isolated compounds were elucidated by comparison of their spectral data such as NMR and ESIMS with reported literature values. Among the isolated compounds, 3 and 4 were isolated for the first time from this fungus.