• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.6
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• pp.799-803
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• 2018

We demonstrated memory thin-film transistors (MTFTs) with organic ferroelectric polymer poly(vinylidene fluoride-co-trifluoroethylene) and an amorphous oxide semiconducting indium gallium zinc oxide channel on the elastomeric substrate. The dielectric constant for the P(VDF-TrFE) thin film prepared on the elastomeric substrate was calculated to be 10 at a high frequency of 1 MHz. The voltage-dependent capacitance variations showed typical butterfly-shaped hysteresis behaviors owing to the polarization reversal in the film. The carrier mobility and memory on/off ratio of the MTFTs showed $15cm^2V^{-1}s^{-1}$ and $10^6$, respectively. This result indicates that the P(VDF-TrFE) film prepared on the elastomeric substrate exhibits ferroelectric natures. The fabricated MTFTs exhibited sufficiently encouraging device characteristics even on the elastomeric substrate to realize mechanically stretchable nonvolatile memory devices.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.79-82
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• 2017

An inky cap, Coprinus comatus synthesizes and secretes a laccase in the liquid yeast extract peptone dextrose medium. We have successfully purified the enzyme through the ion-exchange chromatography and the preparative gel electrophoresis. The estimated molecular weight was 67 kDa by the SDS-PAGE analysis. Optimum pH was pH 4.3 and optimum temperature was $25^{\circ}C$. The Km value was 0.45 mM and the Vmax was 0.0132 OD/min/unit for o-tolidine. Purified laccase showed 49.3% decolorizing activity against remazol brilliant blue R (RBBR) and 41.6% decolorizing activity against Poly R-478 after 12 h incubation.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.67-75
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• 2021

As pass the three revised bills, the Personal Information Protection Act was revised to have a larger application for personal information. For an industrial development through an efficient and secure usage of personal information, there is a need to revise the existing anonymity processing method. This paper modifies the Zero Knowledge Proofs algorithm among the anonymity processing methods to modify the anonymity process calculations by taking into account the reliability of the used service company. More detail, the formula of ZKP (Zero Knowledge Proof) used by ZK-SNAKE is used to modify the personal information for pseudonymization processing. The core function of the proposed algorithm is the addition of user variables and adjustment of the difficulty level according to the reliability of the data user organization and the scope of use. Through Setup_p, the additional variable γ can be selectively applied according to the reliability of the user institution, and the degree of agreement of Witness is adjusted according to the reliability of the institution entered through Prove_p. The difficulty of the verification process is adjusted by considering the reliability of the institution entered through Verify_p. SimProve, a simulator, also refers to the scope of use and the reliability of the input authority. With this suggestion, it is possible to increase reliability and security of anonymity processing and distribution of personal information.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.6
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• pp.67-76
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• 2001

In this paper, we investigate criteria for evaluating cryptographic strength based on randomness testing of the advanced encryption standard candidates, which have conducted by NIST(National Institute of Standards & Technology). It is difficult to prove that a given cryptographic algorithm meets sufficient conditions or requirements for provable security. The statistical testing of random number generators is one of methods to evaluate cryptographic strength and is based on statistical properties of random number generators. We apply randomness testing on several cryptographic algorithms that have not been tested by NIST and find criteria for evaluating cryptographic strength from the results of randomness testing. We investigate two criteria, one is the number of rejected samples and the other is the p-value from p-values of the samples.

• Journal of the Korean Chemical Society
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• v.67 no.5
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• pp.339-347
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• 2023

In this study, a nanocomposite of multi-walled carbon nanotubes@poly(p-phenylenediamine)-Prussian blue (MWCNTs@PpPD-PB) was synthesized and employed for the electrochemical detection of hydrogen peroxide (H₂O₂). A straightforward approach was utilized to prepare an electrochemical H₂O₂ sensor using a MWCNTs@PpPD-PB modified glassy carbon electrode, and its electrochemical behavior was investigated through techniques such as electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The modified electrode displayed a favorable electrocatalytic response towards the reduction of H₂O₂ in an acidic solution. The developed sensor exhibited linearity in the concentration range of 0.005 mM to 2.225 mM for H₂O₂, with high sensitivity (583.6 ㎂ mM^-1cm^-2) and a low detection limit (0.95 ㎛, S/N = 3) at an applied potential of +0.15 V (vs. Ag/AgCl). Additionally, the sensor demonstrated excellent selectivity, reproducibility, and stability. Moreover, successful detection of H₂O₂ was achieved in real samples.

• The Journal of Korean Physical Therapy
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• v.36 no.2
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• pp.67-70
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• 2024

Purpose: This study investigated the effect of virtual reality and Schroth breathing exercises on the lung function characteristics of normal adults in their 20s. Methods: The subjects were randomly divided into groups with ten people each in the experimental groups, namely the virtual reality breathing exercise group (BBEG) and the Schroth breathing exercise group (SBEG), and the control group. The experimental groups performed each breathing exercise for 4 weeks. Subsequently, pulmonary function test indicators such as the forced vital capacity (FVC) and the forced expiratory volume (FEV1) were measured. Results: In the within-group comparison of the subjects before and after the exercises, there was a significant difference in the FVC and FEV1 (p<0.05), but there was no significant difference in FEV1/FVC. The result of the difference test between groups showed that there was a significant difference in FEV1/FVC after exercise (p<0.05). However, there were no significant differences in the remaining items (p>0.05). Conclusion: Improvement in lung function was seen in both exercise groups, and the changes in FEV1/FVC indicated significant improvement in the lung function of the experimental groups compared to the control group.

• Tuberculosis and Respiratory Diseases
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• v.67 no.6
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• pp.517-527
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• 2009

Background: Bronchiectasis (BE) remains a rare respiratory disease in Korea. This retrospective study was done to investigate the potential pathogenic microorganisms (PPMs) that cause in patients with BE, through the use of sputum specimens. Methods: One hundred eleven adult patients, who had undergone chest computed tomography (CT), sputum gram stain/culture, and BE detected by chest CT, were included in this study. Sputum adequacy was determined by using Murray-Washington classification. Results: The mean (${\pm}$SD) age of patients was 60.9 (${\pm}$14.0). The number of PPMs was 167 (67%) in the total 248 isolated organisms. The most frequent PPMs were P. aeruginosa (23.4%), K. pneumoniae (10.5%), and S. aureus (8.4%). The proportion of adequate sputum (AS) was 25.8% in the total sputum specimens. The patients with AS were 41 (37%) and the patients with inadequate sputum (IS) were 70 (63%). The proportion of P. aeruginosa was higher in AS compared to that of IS (44% vs. 19%, p=0.004). The BE score was also higher in P. aeruginosa (+) patients compared to that of P. aeruginosa (-) patients (10.8 vs. 7.6, p=0.001). Conclusion: Although the proportion of AS in the total sputum was low, PPMs were isolated in most patients with BE. It is likely that P. aeruginosa was isolated in AS and AS patients had higher BE scores.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4751-4758
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• 2013

Background: To investigate the predictive and prognostic effects of clinicopathologic and immunohistochemical (IHC) features in patients with gastrointestinal stromal tumours (GISTs). Materials and Methods: Fifty-six patients who were diagnosed with GIST between 2002 and 2012 were retrospectively evaluated. Relationships between clinicopathologic/immunohistochemical factors and prognosis were investigated. Results: Median overall survival (OS) of the whole study group was 74.9 months (42.8-107.1 months), while it was 95.2 months in resectable and 44.7 months in metastatic patients respectively (p=0.007). Epitheliolid tumor morphology was significantly associated with shortened OS as compared to other histologies (p=0.001). SMA(+) tumours were significantly correlated with low (<10/50HPF) mitotic activity (p=0.034). Moreover, SMA(+) patients tended to survive longer and had significantly longer disease-free survival (DFS) times than SMA (-) patients (37.7 months vs 15.9 months; p=0.002). High Ki-67 level (${\geq}30%$) was significantly associated with shorter OS (34 vs 95.2 months; 95%CI; p=0.001). CD34 (-) tumours were significantly associated with low proliferative tumours (Ki-67<%10) (p=0.026). Median PFS (progression-free survival) of the patients who received imatinib was 36 months (27.7-44.2 months). CD34 (-) patients had significantly longer PFS times than that of negative tumours; (50.8 vs 29.8 months; p=0.045). S100 and desmin expression did not play any role in predicting the prognosis of GISTs. Multivariate analysis demonstrated that ${\geq}10/50HPF$ mitotic activity/HPF was the only independent factor for risk of death in GIST patients. Conclusions: Despite the negative prognostic and predictive effect of high Ki-67 and CD34 expression, mitotic activity remains the strongest prognostic factor in GIST patients. SMA positivity seems to affect GIST prognosis positively. However, large-scale, multicenter studies are required to provide supportive data for these findings.

• Journal of Korean society of Dental Hygiene
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• v.8 no.3
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• pp.149-160
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• 2008

This study has been performed for patients who visited dental clinic in Daegu and kyungpook area. The oral health care, dental treatments about the use of oral hygiene devices were obtained through self-administering questionnaires from 1 to 30, August, 2006. The obtained results were as follows: 1. The average percent of using dental floss was 34.2%, followed by interproximal brush was 33.9%, mouthrinse was 33.5%, electric toothbrush was 19.6%, orthodontic brush was 10.6%, and tongue cleaner was 10.2%. 2. Poor to perceive oral health was 36.4% in the patients who perceived oral hygiene device, and there was statistically significant difference (p<0.05). Moderate to perceive oral health was 40.8% in the patients who using oral hygiene device, and there was also statistically significant difference (p<0.05). 3. In the patients who 3 or 4 times toothbrushing a day, the average percent of perceived oral hygiene device was 67.7%, and the average percent of using oral hygiene device was 59.8% (p<0.05). In the patients who had experience of toothbrush education, the average percent of perceived oral hygiene device was 81.8%, and the average percent of using oral hygiene device was 58.1% (p<0.05). 4. The average percent of perceived oral hygiene device was 67.9% in dental implant treated patient, and was 69.0% in patients with cold teeth (p<0.05). The average percent of using oral hygiene device was 64.2% in prosthesis treated patient, and was 83.3% in patients with cold teeth (p<0.05). The average percent of non-using oral hygiene device was 67.6% in orthodontic treated patient (p<0.05). 5. In patient with periodontal disease, the average percent of using interproximal brush was 44.3%, followed by dental floss was 35.4%, mouthrinse was 27.8%, and electric toothbrush was 21.5%. In prosthesis treated patient, the average percent of using interproximal brush was 31.6%, followed by dental floss was 28.9%, and mouthrinse was 23.7%. In orthodontic treated patient, the average percent of using orthodontic brush was 82.4%, followed by interproximal brush was 64.7%, and mouthrinse was 47.1%. In dental implant treated patient, the average percent of using interproximal brush was 50.0%, followed by mouthrinse was 46.4%, and dental floss was 25.0%.

• Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.6.1-6.5
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• 2016

Psenes arafurensis, belonging to the family Nomeidae, is described based on four specimens (184.8-199.0 mm in standard length) collected from Korea. The species is most similar to the congeneric species P. maculatus and P. pellucidus, but differs from them in the number of lateral-line scales. (44-47 in P. arafurensis vs 67-70 in P. maculatus and 120 in P. pellucidus) and the number of vertebrae (31 in P. arafurensis vs 34-38 in P. maculatus and 40-42 in P. pellucidus). The present study is a new record of P. arafurensis with voucher specimens from Korean waters.