• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.8
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• pp.9-16
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• 2000

MOS transistors are fabricated and evaluated for RF IC applications such as mobile communication systems using 0.35m CMOS process. Characteristics of MOSFETs are analyzed at various channel length, width and bias conditions. From the analysis, cut-off frequency ($f_T$) is independent on channel width but maximum oscillation frequency ($f_{max}$) tends to derease as the channel width increases. As channel length increases, $f_T$ and fmax decrease. $f_T$ is 22GHz and fmax is 28GHz at its maximum value. High frequency noise performance is improved with larger channel width and smaller channel length at same bias conditions. NFmin at 2GHz is 0.45dB as a minimum value. From the evaluation, MOSFETs designed using 0.35m CMOS process demonstrated a full potential for the commercial RF ICs for mobile communication systems near 2GHz. And optimization methods of the CMOS transistors for RF applications are presented in this paper.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.366-372
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• 2019

In this paper, we fabricated a capacitive humidity sensor with an IDT(Interdigitated) electrode using commercial polyimide containing fluorine, and its properties were measured and analyzed. First, in order to analyze the composition of commercial polyimide, EDS analysis was performed after patterning process on a silicon wafer. The area of the humidity sensor was $1.56{\times}1.66mm^2$, and the width of the electrode and the gap between the electrodes were $3{\mu}m$ each. The number of electrodes was 166 and the length of the electrode was 1.294mm for the sensitivity of the sensor. The fabricated sensor showed that the sensitivity was 24 fF/%RH, linearity <${\pm}2.5%RH$ and hysteresis <${\pm}4%RH$. As a result of measuring the capacitance value according to the frequency change, the capacitance vlaue decreased with increasing frequency. Capacitance deviations with 10kHz and 100kHz were measured as 0.3pF on average.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.183-188
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• 2011

The electronic structure and properties of Ni$(C_6H_{4-n}F_n)(CO)_2$ ($C_6H_4$=benzyne, n=1-4) complexes have been investigated using hybrid density functional B3LYP theory. Both aromatic natures and nucleus independent chemical shift (NICS) of the benzyne rings have been analyzed. Among mono-, di-, and tri-fluorinated complexes, 3-F, 3,6-F, and 4-H are the most stable isomers, respectively. NICS values calculated at the several points above the ring centers are consistent with those based on the relative energies of the complexes. The atoms in molecules (AIM) analysis indicates that Ni-C bond distance is well correlated with the electron density of a ring critical point (${\rho}_{rcp}$) in all species.

• Journal of IKEEE
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• v.25 no.4
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• pp.774-777
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• 2021

In this paper, we analyzed the gate controllability of 3D NAND Flash Memory with Charge Trap Flash using Ferroelectric (CTF-F) structure. HfO₂, a ferroelectric material, has a high-k characteristic besides polarization. Due to these characteristics, gate controllability is increased in CTF-F structure and on/off current characteristics are improved in Bit Line(BL). As a result of the simulation, in the CTF-F structure, the channel length of String Select Line(SSL) and Ground Select Line(GSL) was 100 nm, which was reduced by 33% compared to the conventional CTF structure, but almost the same off-current characteristics were confirmed. In addition, it was confirmed that the inversion layer was formed stronger in the channel during the program operation, and the current through the BL was increased by about 2 times.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.812-815
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• 2005

Effects of poly-${\gamma}$-glutamate (PGA) on antioxidative characteristics of amino-carbonyl reaction products of glucose were investigated. Rapid browning reaction was observed under heat and alkaline condition (pH 8.2). Browning products were separated by Sephadex G-50, and brown color intensity and electron-donating ability of DPPH (2,2-diphenyl-1-picrylhydrazyl) of each fraction were measured. Fraction-7 (F-7) and -20 (F-20) showed high DPPH scavenging values. UV-VIS absorption spectrum of F-20 was similar to melanoidin peak, and F-7 showed maximum absorption peak at 270 nm. Molecular weight of F-7 was over 35 kDa as determined by SDS-PAGE. Although F-20 could not be measured on SDS-PAGE, its size was smaller than F-7.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.24-30
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• 2009

Purpose: Today, Prostate cancer has been gradually increasing, according to the change of internal incidence rate of cancer. Generally, prostate cancer has lead to dead over 90%, in case of metastasis of lymph node and bone. So, innovative development of new radiopharmaceutical and imaging modality is progressed for detection of that metastasis, in nuclear medicine, now. Therefore, this study shows the usefulness of $^{18}F$-Fluoride PET/CT improved diagnosability on bone metastasis of prostate cancer. Materials and Methods: In this study, 33 male patients with prostate cancer were examined (The mean age: $67.8{\pm}10.2$ years old). Every patient was done each whole body bone scan (WBBS) and $^{18}F$-Fluoride positron emission tomography/computed tomography ($^{18}F$-Fluoride PET/CT). And then, using Receiver Operating Characteristic Curve (ROC curve), each sensitivity and specificity of two modalities was measured and compared with. Results: In 22 patients (66.6%) of all, bone metastasis was detected. And, in WBBS, sensitivity was 63.6%, specificity, 81.8%; in $^{18}F$-Fluoride PET/CT, sensitivity was 100% and specificity was 90.9%. As a result of ROC curve, AUROC (The Area under an ROC) of WBBS was 0.778, and that of $^{18}F$-Fluoride PET/CT, 0.942. Conclusions: $^{18}F$-Fluoride PET/CT was higher both sensitivity and specificity than WBBS, and it was valuable to detect bone metastasis of prostate cancer more definitely, with 3D imaging realization. Also, in $^{18}F$-Fluoride PET/CT, physiological images were acquired in more short time than WBBS, so, it was possible to reduce patient's waiting time and complaint. Therefore, it is considered that $^{18}F$-Fluoride PET/CT is able to improve diagnosability by offering more accurate images, as cuts in a share of high cost.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.342-347
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• 1989

by use of HCl-Giemsa technique and light microscope, dividing vegetative nuclei in hyphae of Fusarium species were observed and the results are summerized. The chromosome number of these fungi was ranged 4 to 8. Of the 20 strains, the highest haploid chromosome number is 8 in F. solani S Hongchun K4, F. moniliforme (from banana) and F. raphani (from radish). The lowest is 4 in F. sporotrichioides NRRL 3510 and F. equiseti KFCC 11843 IFO 30198. F. solani 7468 (from Sydney), F. solani 7475 (from Sydney), F. oxysporum(from tomato). F. roseum (from rice), F. sporotrichioides C Jngsun 1, F. equiseti C Kosung 1 and F. avenaceum 46039 are n=7. F. moniliforme (from rice) F. graminearum, F. proliferatum 6787 (from Syndey), F. proliferatum 7459 (from Synder) and F. anguioides ATCC 20351 are n=6. F. moniliforme NRRL 2284, F. poae NRRL 3287 and F. trincinctum NRRL 3299 are n=5. From these results, it may be concluded that the basic haploid chromosome number of the genus Fusarium is 4 and mat have been evolutionary variation of chromosome number through aneuploidy and polyploidy.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1019-1021
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• 1995

Light induced degradation of hydrogenated amorphous silicon(a-Si:H) are related to the number of weak dangling bonds which are thought to be responsible for the Staebler-Wronski effects, and caused the many photoelectric problems in applications of thin film transistors and solar cell, etc. In this paper, we deposited fluorinated amorphous silicon films(a-Si:H;F) with $SiH_4$ and $SiF_4$ gas mixture and investigated the effects of fluorine atoms on the evoluations of the crystallinity and improvements of light instability. We have found that micro-crystallinity produced in a-SI:H;F films and marked maximum value of 22% at the flow rate of $SiH_4:SiF_4$=2:10 sccm by UV spectrophotometer measurement, while n-Si:H film deposited with only $SiH_4$ gas showed no crystallinity. Light-induced degradation property of a-Si:H;F films is also improved which is mainly due to the etching effects of fluorine atoms on the weak Si-Si bonds and unstable hydrogen bonds. It is considered that involving fluorine atoms in a-Si:H films may contribute to the suppression of light-induced degradation and evolution of micro-crystallinity.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.3
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• pp.266-276
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• 2020

The purpose of this study was to compare the remineralization effect of 38% silver diamine fluoride (SDF) and 5% sodium fluoride (NaF) varnish on artificially induced enamel caries. The present study standardized the physiochemical characteristics of the tooth structure using bovine teeth, realized the wash-off action of agents using a saliva, reproduced an environment similar to mouth through pH-cycling, and comparatively assessed the remineralization effect of 38% SDF and 5% NaF varnish in a non-destructive method using micro-CT. And the remineralized enamel surface structure was analyzed by scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDS). In both SDF and NaF varnish, mineral density (△Hounsfield unit value) and the volume of enamel restored to normal mineral density through remineralization gradually increased with time. And the SDF showed a much higher level of increase in mineral density at all depths and remineralized volume than NaF varnish. According to SEM analysis, the surface roughness decreased in the order of artificial saliva, NaF varnish and SDF. In addition, EDS analysis showed that silver ion was precipitated on the enamel surface in SDF group. In conclusion, SDF had a greater remineralization effect than NaF varnish on demineralized enamel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.31-38
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• 2017

In this paper, we have designed MIMO system using F-OFDM modulation. And then, we have evaluated and analyzed synchronization performance of the system. In this paper we have considered Schmidl's method, Minn's method, and Park's method. As simulation results, Schmidl's method has wide plateau of timing metric and Park's method has impulse-shape timing metric. Also, we can confirm that timing metric characteristic of synchronization estimator can be degraded by adjusting filter length of F-OFDM system. Especially, we can confirm that timing metric of synchronization estimator is shifted according to filter length of MIMO system using F-OFDM modulation and this timing metric movement can be compensated by using designed filter length.