• Clinical and Experimental Pediatrics
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• v.50 no.8
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• pp.740-745
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• 2007

Purpose : There is a dominant opinion that in vitro fertilization (IVF) leads to an increased incidence of twins, low birth weight (LBW) infants, prematurity and mortality. On the other hand, technical development of IVF and improvement of neonatal intensive care have increased the survival rate of neonates. The purpose of this study was to verify the tendency by comparing the clinical aspects of IVF and spontaneously conceived twins, and to establish methods to increase the survival rate of neonates after IVF. Methods : Retrospective reviews were performed on all twin infants who were admitted to the nursery and NICU at Kangnam Sacred Heart Hospital, Hallym University from January 1, 2000 to December 31, 2006. Medical records of IVF twins (study group, n=92) and spontaneously conceived twins (control group, n=265) were analyzed and compared. Neonatal outcomes and complications, as well as obstetric outcomes, were analyzed and compared. Results : Mean gestational age and birth weight of the study group ($34.6{\pm}3.5$ weeks, $2,203.9{\pm}617.2g$) were considerably lower than those of the control group ($36.3{\pm}2.4$ weeks, $2,367.0{\pm}517.9g$). The frequency of prematurity less than 37 weeks (68.5% vs 51.3%) and extremely LBW (15.2% vs 6.4%) were also significantly higher in the study group. Other neonatal outcomes were all insignificant. The obstetric characteristics, maternal age ($32.6{\pm}3.3$ years vs $30.3{\pm}3.9$ years) and the frequency of cesarean delivery(95.7% vs 79.9%) were significantly higher in the study group. Other obstetric outcomes were insignificant except for the frequency of incompetent internal os of cervix (36.2% vs 3.6%) and cerclage operation (38.3% vs 4.3%). Conclusion : Based on the above results, clinical outcomes of twin infants will be further improved by careful attention and thorough antenatal care of the IVF twins.

• Sleep Medicine and Psychophysiology
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• v.6 no.1
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• pp.52-60
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• 1999

Objectives: With the object of finding the appropriate conditions and algorithms for dimensional analysis of human EEG, we calculated correlation dimensions in the various condition of sampling rate and data aquisition time and improved the computation algorithm by taking advantage of bit operation instead of log operation. Methods: EEG signals from 13 scalp lead of a man were digitized with A-D converter under the condition of 12 bit resolution and 1000 Hertz of sampling rate during 32 seconds. From the original data, we made 15 time series data which have different sampling rate of 62.5, 125, 250, 500, 1000 hertz and data acqusition time of 10, 20, 30 second, respectively. New algorithm to shorten the calculation time using bit operation and the Least Trimmed Squares(LTS) estimator to get the optimal slope was applied to these data. Results: The values of the correlation dimension showed the increasing pattern as the data acquisition time becomes longer. The data with sampling rate of 62.5 Hz showed the highest value of correlation dimension regardless of sampling time but the correlation dimension at other sampling rates revealed similar values. The computation with bit operation instead of log operation had a statistically significant effect of shortening of calculation time and LTS method estimated more stably the slope of correlation dimension than the Least Squares estimator. Conclusion: The bit operation and LTS methods were successfully utilized to time-saving and efficient calculation of correlation dimension. In addition, time series of 20-sec length with sampling rate of 125 Hz was adequate to estimate the dimensional complexity of human EEG.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.525-530
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• 2011

Pine needles have long been used as a traditional health-promoting medicinal food in Korea. This study was carried out to investigate the effects of pine needle extracts on the antioxidant activity, and proliferation of osteoclastic RAW 264.7 cells. Pine needle extracts were examined using hot water, ethanol, hexane, hot water-ethanol, and hot water-hexane. The effects of the pine needle extracts were examined by comparing the results with that of a commercial agents, proanthocyanidin. Analysis of each extract indicated that hot water-ethanol and ethanol extracts contained the highest total polyphenol concentrations. The hot water-ethanol and ethanol extracts also showed relatively the highest SOD-like activity. The proliferation of osteoclastic RAW 264.7 cells treated with pine needle extracts was decreased by lower than 70%. In addition, the hot water and ethanol extracts of pine needle significantly reduced the number of tartrate-resistant acid phosphatase-positive ($TRAP^+$) multinucleated cells from osteoclatic RAW 264.7 cells. These results indicate that pine needle extracts had an anabolic effect on bone through the promotion of osteoclast differentiation, suggesting that they could be used for the treatment of common metabolic bone diseases.

• Analytical Science and Technology
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• v.13 no.4
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• pp.494-503
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• 2000

A 21-residue peptide corresponding to amino acids 84-104 of $p16^{INK4A}$, the tumor suppressor, has been synthesized and its structure was studied by Circular Dichroism, $^1H$ NMR spectroscopy and molecular modeling. A p16-derived peptide (84-104 amino acids) forming stable complex with CDK4 and CDK6 inhibits the ability of CDK4/6 to phosphorylate pRb in vitro, and blocks cell-cycle progression through G1/S phase as shown in the function of the full-length p16. Its NMR spectral data including NOEs, $^3J_{NH-H{\alpha}}$ coupling constants, $C_{\alpha}H$ chemical shift, the average amplitude of amide chemical shift oscillation and temperature coefficients indicate that the secondary structure of a p16-derived peptide is similar to that of the same region of full-length p16, which consists of helix-turn-helix structure. The 3-D distance geometry structure based on NOE-hased distance and torsion angle restraints is characterized by ${\gamma}$-turn conformation between residues $Gly^{89}-Leu^{91}$(${\varphi}_{i+1}=-79.8^{\circ}$, ${\varphi}_{i+1}=60.2^{\circ}$) as evidenced in a single crystal structure for the corresponding region of p18 or p19, but is undefined at both the N and C termini. This compact and rigid ${\gamma}$-turn region is considered to stabilize the structure of p16-derived peptide and serve as a site recognizing cyelin dependent kinase, and this well-defined ${\gamma}$-turn structure could be utilized for the design of anti-cancer drug candidates.

• Conservation Science in Museum
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• v.14
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• pp.91-113
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• 2013

Cheongpung Buwongun Kim Wu-myeong's Funeral Bier, an important folklore cultural property No.120, possessed by Chuncheon National Museum was donated in 2002 (by Kim Seonggu). It consists of a bier, yoyeo(腰輿), myeongjeongdae(銘旌臺), and manjangdae(輓章臺). It has a high value as the oldest royal bier. The bier which had a resting time in the storage for special exhibition of "The great cultural treasure of Gangwon province" was inspected in September 2012 and colored pigment layer of the wooden part had the risk of peeling off and surface damage of the textile was serious. Therefore, conservation treatment was conducted. In addition, knots and susiks(垂飾) were severely damaged and their exhibition was impossible. Therefore, a reproduction to replace them through a close investigation was made. All parts of the funeral bier were in separation except for the basic furniture. Conservation was made by dividing the parts into wooden parts and textile parts. Yoyeo was reinforced after disassembling bujae from it and then was reassembled. Paraloid B-72 2 wt% (in ethyle acetate), acrylic resin, was applied to the wooden part of the bier in order to reinforce the colored pigment layer with the addition of sodium alginate 2 wt%(in stilled water) and glue 4 wt%(in stilled water). The pollutants on the surface of the textile part were removed (vacuuming) and its creases were smoothed out (steaming). Fat-soluble pollutants were removed using an nonionic surfactant(Saponin, concentration at 0.25 to 0.5 g/𝑙, in de-ionized water). After the disassembly of the yoyeo from the broken wooden, it was bonded with glue (3 wt% for the first gluing, 35 wt% for gluing), and pine wood was used to restore missing parts. In the process of connecting Wongak(雲角), the original metal hinge and nails were reused to complete the assembly.

• Clean Technology
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• v.28 no.1
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• pp.63-78
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• 2022

Electronics industrial wastewater treatment facilities release organic wastewaters containing high concentrations of organic pollutants and more than 20 toxic non-biodegradable pollutants. One of the major challenges of the fourth industrial revolution era for the electronics industry is how to treat electronics industrial wastewater efficiently. Therefore, it is necessary to develop an electronics industrial wastewater modeling technique that can evaluate the removal efficiency of organic pollutants, such as chemical oxygen demand (COD), total nitrogen (TN), total phosphorous (TP), and tetramethylammonium hydroxide (TMAH), by digital twinning an electronics industrial organic wastewater treatment facility in a cyber physical system (CPS). In this study, an electronics industrial wastewater activated sludge model (e-ASM) was developed based on the theoretical reaction rates for the removal mechanisms of electronics industrial wastewater considering the growth and decay of micro-organisms. The developed e-ASM can model complex biological removal mechanisms, such as the inhibition of nitrification micro-organisms by non-biodegradable organic pollutants including TMAH, as well as the oxidation, nitrification, and denitrification processes. The proposed e-ASM can be implemented as a Water Digital Twin for real electronics industrial wastewater treatment systems and be utilized for process modeling, effluent quality prediction, process selection, and design efficiency across varying influent characteristics on a CPS.

• Clean Technology
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• v.28 no.1
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• pp.79-93
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• 2022

In this study, an electronics industrial wastewater activated sludge model (e-ASM) to be used as a Water Digital Twin was calibrated based on real high-tech electronics industrial wastewater treatment measurements from lab-scale and pilot-scale reactors, and examined for its treatment performance, effluent quality prediction, and optimal process selection. For specialized modeling of a high-tech electronics industrial wastewater treatment system, the kinetic parameters of the e-ASM were identified by a sensitivity analysis and calibrated by the multiple response surface method (MRS). The calibrated e-ASM showed a high compatibility of more than 90% with the experimental data from the lab-scale and pilot-scale processes. Four electronics industrial wastewater treatment processes-MLE, A2/O, 4-stage MLE-MBR, and Bardenpo-MBR-were implemented with the proposed Water Digital Twin to compare their removal efficiencies according to various electronics industrial wastewater characteristics. Bardenpo-MBR stably removed more than 90% of the chemical oxygen demand (COD) and showed the highest nitrogen removal efficiency. Furthermore, a high concentration of 1,800 mg L^-1 T MAH influent could be 98% removed when the HRT of the Bardenpho-MBR process was more than 3 days. Hence, it is expected that the e-ASM in this study can be used as a Water Digital Twin platform with high compatibility in a variety of situations, including plant optimization, Water AI, and the selection of best available technology (BAT) for a sustainable high-tech electronics industry.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.523-541
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• 2023

As accessibility to 3D printers increases, there is a growing frequency of exposure to chemicals associated with 3D printing. However, research on the toxicity and harmfulness of chemicals generated by 3D printing is insufficient, and the performance of toxicity prediction using in silico techniques is limited due to missing molecular structure data. In this study, quantitative structure-activity relationship (QSAR) model based on data-centric AI approach was developed to predict the toxicity of new 3D printing materials by imputing missing values in molecular descriptors. First, MissForest algorithm was utilized to impute missing values in molecular descriptors of hazardous 3D printing materials. Then, based on four different machine learning models (decision tree, random forest, XGBoost, SVM), a machine learning (ML)-based QSAR model was developed to predict the bioconcentration factor (Log BCF), octanol-air partition coefficient (Log Koa), and partition coefficient (Log P). Furthermore, the reliability of the data-centric QSAR model was validated through the Tree-SHAP (SHapley Additive exPlanations) method, which is one of explainable artificial intelligence (XAI) techniques. The proposed imputation method based on the MissForest enlarged approximately 2.5 times more molecular structure data compared to the existing data. Based on the imputed dataset of molecular descriptor, the developed data-centric QSAR model achieved approximately 73%, 76% and 92% of prediction performance for Log BCF, Log Koa, and Log P, respectively. Lastly, Tree-SHAP analysis demonstrated that the data-centric-based QSAR model achieved high prediction performance for toxicity information by identifying key molecular descriptors highly correlated with toxicity indices. Therefore, the proposed QSAR model based on the data-centric XAI approach can be extended to predict the toxicity of potential pollutants in emerging printing chemicals, chemical process, semiconductor or display process.

• Clinical and Experimental Pediatrics
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• v.52 no.5
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• pp.557-566
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• 2009

Purpose : To evaluate the clinical features and characteristics of childhood periodic syndromes (CPS) in Korea using the new criteria of the International Classification of Headache Disorders (ICHD)-II. Methods : The study was conducted at pediatric neurology clinics of five urban tertiary-care medical centers in Korea from January 2006 to December 2007. Patients (44 consecutive children and adolescents) were divided into three groups (cyclic vomiting syndrome [CVS], abdominal migraine [AM], and benign paroxysmal vertigo of childhood [BPVC]) by recurrent paroxysmal episodes of vomiting, abdominal pain, dizziness, and/or vertigo using the ICHD-II criteria and their characteristics were compared. Results : Totally, 16 boys (36.4%) and 28 girls (63.6%) were examined (aged 4-18 yr), with 20 CVS (45.5%), 8 AM (18.2%), and 16 BPVC (36.4%) patients. The mean age at symptom onset was $6.3{\pm}3.6$ yr, $8.5{\pm}2.7$ yr, and $8.5{\pm}2.9$ yr in the CVS, AM, and BPVC groups, respectively, showing that symptoms appeared earliest in the CVS group. The mean age at diagnosis was $8.0{\pm}3.4$ yr, $10.5{\pm}2.6$ yr, and $10.1{\pm}3.2$ yr the CVS, AM, and BPVC groups, respectively. Of the 44 patients, 17 (38.6%) had a history of recurrent headaches and 11 (25.0%) showed typical symptoms of migraine headache, with 5 CVS (25.0%), 2 AM (25.0%), and 4 BPVC (25.0%) patients. Family history of migraine was found in 9 patients (20.4%): 4 in the CVS group (20.0%), 2 in the AM group (25.0%), and 3 in the BPVC group (18.8%). Conclusion : The significant time lag between the age at symptom onset and final diagnosis possibly indicates poor knowledge of CPS among pediatric practitioners, especially in Korea. A high index of suspicion may be the first step toward caring for these patients. Furthermore, a population-based longitudinal study is necessary to determine the incidence and natural course of these syndromes.