• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.128.2-128.2
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• 2014

Long-wave infrared detectors using the type-II InAs/GaSb strained superlattice (T2SL) material system with the nBn structure were designed and fabricated. The band gap energy of the T2SL material was calculated as a function of the thickness of the InAs and GaSb layers by the Kronig-Penney model. Growth of the barrier material (Al0.2Ga0.8Sb) incorporated Te doping to reduce the dark current. The full width at half maximum (FWHM) of the 1st satellite superlattice peak from the X-ray diffraction was around 45 arc sec. The cutoff wavelength of the fabricated device was ${\sim}10.2{\mu}m$ (0.12eV) at 80 K while under an applied bias of -1.4V. The measured activation energy of the device was ~0.128 eV. The dark current density was shown to be $1.2{\times}10^{-5}A/cm^2$ at 80 K and with a bias -1.4 V. The responsivity was 1.9 A/W at $7.5{\mu}m$ at 80K and with a bias of -1.9V.

• Korean Parent-Child Health Journal
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• v.22 no.1
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• pp.22-29
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• 2019

Purpose: This study was conducted to identify the intention of visiting obstetrics and gynecology of female college students by considering their perception and optimistic bias. Methods: The study included a total of 135 female college students under the age of 25. The data collection period is a descriptive research study conducted online from April 8, 2019 to April 16, 2019. The collected data were analyzed using the correlation of t-test, ANOVA, Pearson's correlation and multiple regression using SPSS 20.0. Results: The degree of intention of behavior for visits to obstetrics and gynecology was $3.10{\pm}1.06points$ on average. Intention of behavior for visits to obstetrics and gynecology had significant variance depending on sexual experience (t=3.09, p<.001). The intention of behavior for visits to obstetrics and gynecology had positive correlations with the cognition of visits to obstetrics and gynecology (r=.422, p<.001), the optimism bias (r=.419, p<.001). Influence factors emerged the optimism bias, cognition and sexual experience with explanatory power of 30.4%. Conclusion: The results of this paper can be used to prepare the basic data for the development of educational programs to promote preventive gynecological visits of female college students. Through this, the preventive screening rate, the quality of reproductive health in women's lives.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.127-130
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• 2002

Step-edge dc SQUID magnetometers have been fabricated on sapphire substrate. Ce$O_{2}$ buffer layer and $YBa_{2}$$Cu_{3}$ $O_{7}$(YBCO) films were deposited in-situ on the low angle (~$35^{\circ}$)steps formed on the substrates. Typical 5-$\mu$m-wide junction has $R_{N}$ of 4 $\Omega$ and $I_{c}$ of 60 $\mu$A with $I_{c}$$R_{N}$ product of 240 $\mu$V at 77 K. According to applied bias current, depth of voltage modulation was changed and maximum voltage was measured 100~300 fT/$\checkmark$ Hz at 100 Hz, and about 1.5 pT/$\checkmark$ Hz at 1 Hz. For ac bias reversal method, field noise was decreased in the 1/f region. The QRS peak of magneto-cardiogram was measured 50 pT in the magnetically shielded room.

• Genomics & Informatics
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• v.15 no.4
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• pp.123-127
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• 2017

Synonymous sites are generally considered to be functionally neutral. However, there are recent contradictory findings suggesting that synonymous alleles might have functional roles in various molecular aspects. For instance, a recent study demonstrated that synonymous single nucleotide polymorphisms have a similar effect size as nonsynonymous single nucleotide polymorphisms in human disease association studies. Researchers have recognized synonymous codon usage bias (SCUB) in the genomes of almost all species and have investigated whether SCUB is due to random nucleotide compositional bias or to natural selection of any functional exposure generated by synonymous mutations. One of the most prominent observations on the non-neutrality of synonymous codons is the correlation between SCUB and levels of gene expression, such that highly expressed genes tend to have a higher preference toward so-called optimal codons than lowly expressed genes. In relation, it is known that amounts of cognate tRNAs that bind to optimal codons are significantly higher than the amounts of cognate tRNAs that bind to non-optimal codons in genomes. In the present paper, we review various functions that synonymous codons might have other than regulating expression levels.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.334-342
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• 2005

The prototype Chlorella virus PBCV-l encodes 11 tRNA genes and over 350 protein-encoding genes in its 330 kbp genome. Initial attempts to overexpress the recombinant A189/192R protein, a putative virus attachment protein, in E. coli strain BL21(DE3) SI were unsuccessful, and multiple protein bands were detected on Western blots. However, the full-length A189/192R recombinant protein or fragments derived from it were detected when they were expressed in E. coli BL21 CodonPlus (DE3) RIL, which contains extra tRNAs. Codon usage analysis of the a189/192r gene showed highly biased usage of the AGA and AVA codons compared to genes encoded by E. coli and Chlorella. In addition, there were biases of XXA/U($56\%$) and XXG/ C($44\%$) in the codons recognized by the viral tRNAs, which correspond to the codon usage bias in the PBCV-1 genome of XXA/U ($63\%$) over those ending in XXC/G ($37\%$). Analysis of the codon usage in the major capsid protein and DNA polymerase showed preferential usage of codons that can be recognized by the viral tRNAs. The Asn (AAC) and Lys (AAG) codons whose corresponding tRNA genes are duplicated in the tRNA gene cluster were the most abundant (i.e., preferred) codons in these two proteins. The tRNA genes encoded in the PBCV-l genome seem to play a very important role during the synthesis of viral proteins through supplementing the tRNAs that are frequently used in viral proteins, but are rare in the host cells. In addition, these tRNAs would help the virus to adapt to a wide range of hosts by providing tRNAs that are rare in the host cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.302.1-302.1
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• 2016

Solution-processed amorphous metal-oxide thin-film transistors (TFTs) are considered as promising candidates for the upcoming transparent and flexible electronics due to their transparent property, good performance uniformity and possibility to fabricate at a low-temperature. In addition, solution processing metal oxide TFTs may allow non-vacuum fabrication of flexible electronic which can be more utilizable for easy and low-cost fabrication. Recently, for high-mobility oxide TFTs, multi-layered oxide channel devices have been introduced such as superlattice channel structure and heterojunction structure. However, only a few studies have been mentioned on the bias illumination stress in the multi- layered oxide TFTs. Therefore, in this research, we investigated the effects of bias illumination stress in solution-processed bilayer oxide TFTs which are fabricated by the deep ultraviolet photochemical activation process. For studying the electrical and stability characteristics, we implemented positive bias stress (PBS) and negative bias illumination stress (NBIS). Also, we studied the electrical properties such as field-effect mobility, threshold voltage ($V_T$) and subthreshold slop (SS) to understand effects of the bilayer channel structure.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.1
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• pp.185-202
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• 2013

In this study, we present the nearly complete mitogenome sequences of the garden chafer, Polyphylla laticollis manchurica, which is listed as an endangered species in Korea. The P. l. manchurica mitogenome, which includes unfinished whole A+T-rich region and a partial srRNA was 14,473-bp long, possessing typical sets of genes (13 PCGs, 22 tRNA genes, and 2 rRNA genes). Gene arrangement of the P. l. manchurica mitogenome was identical to the common one found in the majority of insects. The 5 bp-long motif sequence (TAGTA) that has been suggested to be the possible binding site for the transcription termination peptide for the major-strand was also found in the P. l. manchurica mitogenome between $tRNA^{Ser}$(UCN) and ND1. The start codon for COI gene and ATPase8 was designated as a typical TTG. All tRNAs of the P. l. manchurica showed a stable canonical clover-leaf structure of other mt tRNAs, except for $tRNA^{Ser}$(AGN), DHU arm of which could not form stable stemloop structure. As has been previously determined, the high A/T content was unanimously observed in P. l. manchurica in terms of A/T bias in the third codon position (73.5%) compared with the first (66.4%) and second codon position (66.2%). The PCGs encoded in major-strands are slightly T-skewed, whereas those of the minor-strand are A-skewed, indicating strand asymmetry in nucleotide composition in the Coleoptera including P. l. manchurica.

• Transactions on Electrical and Electronic Materials
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• v.18 no.1
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• pp.51-54
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• 2017

TFTs (thin film transistors) were fabricated using a-SIZO (amorphous silicon-indium-zinc-oxide) channel by RF (radio frequency) magnetron sputtering at room temperature. We report the influence of various channel thickness on the electrical performances of a-SIZO TFTs and their stability, using TS (temperature stress) and NBTS (negative bias temperature stress). Channel thickness was controlled by changing the deposition time. As the channel thickness increased, the threshold voltage ($V_{TH}$) of a-SIZO changed to the negative direction, from 1.3 to -2.4 V. This is mainly due to the increase of carrier concentration. During TS and NBTS, the threshold voltage shift (${\Delta}V_{TH}$) increased steadily, with increasing channel thickness. These results can be explained by the total trap density ($N_T$) increase due to the increase of bulk trap density ($N_{Bulk}$) in a-SIZO channel layer.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.11a
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• pp.67-67
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• 2001

The structure zone model has been used to provide an overview of the relationship between the microstructure of the films deposited by PVD and the most prominent deposition condition.s. B.AMovchan and AV.Demchishin have proposed it firstls such model. They concluded that the general features of the resulting structures could be correlated into three zones depending on $T/T_m$. Here T m is the melting point of the coating material and T is the substrate temperature in kelvines. Zone 1 ($T/Tm_) is dominated by tapered macrograins with domed tops, zone 2 ($O.3) by columnar grains with denser boundaries and zone 3 ($T/T_m>O.5$) by equiaxed grains formed by recrystallization. J.AThomton has extended this model to include the effect of the sputtering gas pressure and found a fourth zone termed zone T(transition zone) consisting of a dense array of poorly defined fibrous grains. R.Messier found that the zone I-T boundary (fourth zone of Thorton) varies in a fashion similar to the film bias potential as a function of gas pressure. However, there has not nearly enough model for explaining the change in morphology with crystal orientation of the films. The structure zone model only provide an information about the morphology of the deposited film. In general, the nucleation and growth mechanism for granular and fine structure of the deposited films are very complex in an PVD technique because the morphology and orientation depend not only on the substrate temperature but also on the energy of deposition of the atoms or ions, the kinetic mechanism between metal atoms and argon or nitrogen gas, and even on the presence of impurities. In order to clarify these relationship, AI and Mg thin films were prepared on SPCC steel substrates by PVD techniques. The influence of gas pressures and bias voltages on their crystal orientation and morphology of the prepared films were investigated by SEM and XRD, respectively. And the effect of crystal orientation and morphology of the prepared films on corrosion resistance was estimated by measuring polarization curves in 3% NaCI solution.

• Investigative Magnetic Resonance Imaging
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• v.23 no.2
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• pp.114-124
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• 2019

Purpose: We investigate biases in the assessments of left ventricular function (LVF), by compressed sensing (CS)-cine magnetic resonance imaging (MRI). Materials and Methods: Cardiovascular cine images with short axis view, were obtained for 8 volunteers without CS. LVFs were assessed with subsampled data, with compression factors (CF) of 2, 3, 4, and 8. A semi-automatic segmentation program was used, for the assessment. The assessments by 3 CS methods (ITSC, FOCUSS, and view sharing (VS)), were compared to those without CS. Bland-Altman analysis and paired t-test were used, for comparison. In addition, real-time CS-cine imaging was also performed, with CF of 2, 3, 4, and 8 for the same volunteers. Assessments of LVF were similarly made, for CS data. A fixed compensation technique is suggested, to reduce the bias. Results: The assessment of LVF by CS-cine, includes bias and random noise. Bias appeared much larger than random noise. Median of end-diastolic volume (EDV) with CS-cine (ITSC or FOCUSS) appeared -1.4% to -7.1% smaller, compared to that of standard cine, depending on CF from (2 to 8). End-systolic volume (ESV) appeared +1.6% to +14.3% larger, stroke volume (SV), -2.4% to -16.4% smaller, and ejection fraction (EF), -1.1% to -9.2% smaller, with P < 0.05. Bias was reduced from -5.6% to -1.8% for EF, by compensation applied to real-time CS-cine (CF = 8). Conclusion: Loss of temporal resolution by adopting missing data from nearby cardiac frames, causes an underestimation for EDV, and an overestimation for ESV, resulting in underestimations for SV and EF. The bias is not random. Thus it should be removed or reduced for better diagnosis. A fixed compensation is suggested, to reduce bias in the assessment of LVF.