• Korean Journal of Radiology
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• v.24 no.10
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• pp.1006-1016
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• 2023

Objective: Computed tomography (CT) is an established method for the diagnosis, staging, and treatment of multiple myeloma. Here, we investigated the potential of photon-counting detector computed tomography (PCD-CT) in terms of image quality, diagnostic confidence, and radiation dose compared with energy-integrating detector CT (EID-CT). Materials and Methods: In this prospective study, patients with known multiple myeloma underwent clinically indicated whole-body PCD-CT. The image quality of PCD-CT was assessed qualitatively by three independent radiologists for overall image quality, edge sharpness, image noise, lesion conspicuity, and diagnostic confidence using a 5-point Likert scale (5 = excellent), and quantitatively for signal homogeneity using the coefficient of variation (CV) of Hounsfield Units (HU) values and modulation transfer function (MTF) via the full width at half maximum (FWHM) in the frequency space. The results were compared with those of the current clinical standard EID-CT protocols as controls. Additionally, the radiation dose (CTDIvol) was determined. Results: We enrolled 35 patients with multiple myeloma (mean age 69.8 ± 9.1 years; 18 [51%] males). Qualitative image analysis revealed superior scores (median [interquartile range]) for PCD-CT regarding overall image quality (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), edge sharpness (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), image noise (4.0 [4.0-4.0] vs. 3.0 [3.0-4.0]), lesion conspicuity (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), and diagnostic confidence (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]) compared with EID-CT (P ≤ 0.004). In quantitative image analyses, PCD-CT compared with EID-CT revealed a substantially lower FWHM (2.89 vs. 25.68 cy/pixel) and a significantly more homogeneous signal (mean CV ± standard deviation [SD], 0.99 ± 0.65 vs. 1.66 ± 0.5; P < 0.001) at a significantly lower radiation dose (mean CTDIvol ± SD, 3.33 ± 0.82 vs. 7.19 ± 3.57 mGy; P < 0.001). Conclusion: Whole-body PCD-CT provides significantly higher subjective and objective image quality at significantly reduced radiation doses than the current clinical standard EID-CT protocols, along with readily available multi-spectral data, facilitating the potential for further advanced post-processing.

• Journal of Wetlands Research
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• v.26 no.1
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• pp.1-9
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• 2024

In this study, a HSPF model was developed to simulate runoff and water quality in the Haebancheon watershed, which has a high land area ratio and population density among the West Nakdong River watersheds. Various non-point source pollution control strategies were applied, and the reduction in pollutant loads and the exceedance rate of water quality standards were analyzed. The scenarios included basic road cleaning for reducing pollutant loads, runoff reduction measures considering extensive low-impact development techniques, and inflow reduction measures to mitigate non-point source pollution entering the river. In the first step, practical conditions such as the number of vehicles for road cleaning in Kimhae City were considered, while for the second and third steps, it was assumed that 50% of the applicable land use area was used to be applicable for the LID techniques. As a result of applying all three measures, it was analyzed that the BOD pollutant load could be reduced by 58.28%, T-N by 58.49%, and T-P by 51.56%. Furthermore, the 60th percentile of water quality measurements accumulated over 5 years was set as the target water quality, and a flow-duration curve was constructed. The exceedance rate of the flow-duration curve before and after applying non-point source pollution reduction measures was analyzed. As a result, for BOD, the exceedance rate decreased from 41.57% before applying the measures to 16.32% after, showing a 25.25% reduction in the exceedance rate. For T-N, the exceedance rate decreased significantly from 40.31% before the measures to 22.84% after, and for T-P, it decreased significantly from 62.43% to 27.22%.

• Journal of the Korea Society of Computer and Information
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• v.29 no.5
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• pp.21-29
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• 2024

Reducing the radiation dose during CT scanning can lower the risk of radiation exposure, but not only does the image resolution significantly deteriorate, but the effectiveness of diagnosis is reduced due to the generation of noise. Therefore, noise removal from CT images is a very important and essential processing process in the image restoration. Until now, there are limitations in removing only the noise by separating the noise and the original signal in the image area. In this paper, we aim to effectively remove noise from CT images using the wavelet transform-based GAN model, that is, the WT-GAN model in the frequency domain. The GAN model used here generates images with noise removed through a U-Net structured generator and a PatchGAN structured discriminator. To evaluate the performance of the WT-GAN model proposed in this paper, experiments were conducted on CT images damaged by various noises, namely Gaussian noise, Poisson noise, and speckle noise. As a result of the performance experiment, the WT-GAN model is better than the traditional filter, that is, the BM3D filter, as well as the existing deep learning models, such as DnCNN, CDAE model, and U-Net GAN model, in qualitative and quantitative measures, that is, PSNR (Peak Signal-to-Noise Ratio) and SSIM (Structural Similarity Index Measure) showed excellent results.

• Journal of Korea Water Resources Association
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• v.57 no.5
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• pp.359-369
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• 2024

Korea prepares for potential floods by designating June 21st to September 20th as the flood season. However, many dams in Korea have suffered from extreme floods caused by different climate patterns, as in the case of the longest consecutive rain of 54 days in the 2020's flood season. In this context, various studies have tried to develop novel methodologies to reduce flood damage, but no study has ever dealt with the validity of the current statutory flood season thus far. This study first checked the validity of the current flood season through the observation data in the 21st century and proved that the current flood season does not consider the effects of increasing precipitation trends and the changing regional rainfall characteristics. In order to deal with these limitations, this study suggested seven new alternative flood seasons in the research area. The rigid reservoir operation method (ROM) was used for reservoir simulation, and the long short-term memory (LSTM) model was used to derive predicted inflow. Finally, all alternatives were evaluated based on whether if they exceeded the design discharge of the dam and the design flood of the river. As a result, the floods in the shifted period were reduced by 0.068% and 0.33% in terms of frequency and duration, and the magnitude also decreased by 24.6%, respectively. During this period, the second evaluation method also demonstrated that flood decreased from four to two occurrences. As the result of this study, the authors expect a formal reassessment of the flood season to take place, which will ultimately lead to the preemptive flood response to changing precipitation patterns.

• Clinical and Experimental Pediatrics
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• v.50 no.6
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• pp.565-569
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• 2007

Purpose : With a duration of action of approximately 24 hours and peakless levels, Lantus is a more physiologic basal insulin analogue compared with NPH. The aim of this study was to compare the glycemic control of Lantus plus Humalog with that of premixed insulin in children and adolescents with type 1 diabetes mellitus. Methods : The subjects consisted of 25 patients with type 1 diabetes mellitus, aged 12-19 years, who changed their insulin regimen from premixed insulin to Lantus plus Humalog. Daily insulin doses, frequency of hypoglycemia, fasting blood glucose, C-peptide concentration and HbA1c before and 6 months after Lantus treatment were compared. 24 hour blood glucose of 11 patients among Lantus treatment group (n=25) and premixed insulin treatment group (n=10) were self-monitored and compared. Results : 6 months after Lantus treatment, the episodes of hypoglycemia were reduced by 50%(15.1 vs. 7.6 events/month), especially nocturnal hypoglycemia by 67%(6.7 vs. 2.5 events/month). HbA1c was reduced from 9.3% to 8.7% after Lantus treatment. Self-monitored blood glucose of Lantus treatment group at postbreakfast 30, 60, 90 and 120 minutes were 171.1, 169.5, 171.0 and 154.1 mg/dL respectively and lower than those of premixed insulin treatment group (259.7, 282.7, 280.0 and 250.9 mg/dL respectively). Conclusion : Compared with premixed insulin, Lantus plus Humalog is more effective in glycemic control and reduction in nocturnal hypoglycemia in children and adolescents with type 1 diabetes mellitus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.352-361
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• 1990

The reducing effect of wind injury was investigated using several wind-break nets in Youngdeok province where cold-wind damage is often occurred during rice growing season. The white-head damage of rice have been often occurred by typhoon during the period between August 15 to September 10 in the cold wind area of the eastern coastal during the last 11 years (1979-1989). This may suggest that the critical period for heading will be by August 15 in the regions. High evaporation coefficient, more than 250 due to typhoon passage over the regions resulted high injury of white head. Generally, the wind injury have been caused by warm and dry westerlies through Fohn apperance in Taebaeg mountains and by cool-humid wind which blows from coast to inland. The frequency of occurrence of the two types of typhoons were 25, 20%, respectively during rice cultivation. The instalation of wind-break net significantly reduced the wind blowing speed, depending on the net mesher with the higher effect in dence net. The distances between the net and cropping area also affect the wind speed: 23% reduction at 1m distance. 34% at 10m and 28% at 20m, respectively. The reducing effect was also observed even at 10 times height of the wind-break net. The instalation of wind-break net gave several effects on climate factor, showing that temperature increased by 0.8$^{\circ}C$(maximum), 0.7$^{\circ}C$(minimum), 0.6$^{\circ}C$(average) : water temperatures increased by 0.5$^{\circ}C$(maximum), 0.6$^{\circ}C$(minimum), 0.5$^{\circ}C$(average) : soil temperature increased 0.4$^{\circ}C$. The earlier heading and increasing growth rate, use of light, culm length, panicle number per hill, spikelet number per panicle, fertility and 1,000 grain weight were observed in the fields with the wind-break nets resulting in 10-15% increase in rice yield using 0.5${\times}$0.5cm nets. The increasing seedlings per hill gave higher grain yield by 13% in the cold wind damage regions of eastern coastals. and the wind-break was more significant in the field without the wind-break net. Wind injury of rice plant in the cold wind regions of eastern coastals in korea could be reduced by selection of tolerant varieties to wind injury, adjustment of transplanting time, and establishment of wind-break nets.

• Childhood Kidney Diseases
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• v.5 no.2
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• pp.109-116
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• 2001

Purpose Long- term use of steroid, cyclophosphamide and cyclosporin, which are frequently used in the therapy of SDNS, might cause severe side effects. Recently, the immune-modulator levamisole has been tried as a substitute therapy and it has been reported as a method with less side effects and more effectiveness. We started this research in order to observe the effects of levamisole and compare it to other therapy results. Patients and Methods : We chose 16 steroid dependent nephrotic syndrome children, those who had shown frequent relapse during the immunocompromised therapy period. Mean age was $9.1{\pm}1.4$ years in children and the male to female ratio was 15:1. All of subjects were diagonized with MCNS and had received cyclophosphamide or cyclosporin before receiving levamisole. Levamisole at a dose of 2.5mg/kg was used every other day for 1 year and the relapse rate was observed. Results : On average of 14 days after treatment, complete remission was visible in all of the children, and the relapse percentage was $50\%$, which represents 8 children, while remaining 8 children representing $50\%$ of the cases showed no relapse during treatment. During the levamisole therapy period, tile average relapse rate was reduced significantly from $2.18{\pm}0.9/year\;to\;0.77{\pm}0.9/year$(P=0.027). Also the average relapse rate after the therapy was reduced to $1.34{\pm}1.1/year$, which was a significant level compared to the level before treatment(P=0.003). There was no significant difference in terms of duration of remission maintenance. Duration of remission maintenance showed an average of $12.2{\pm}9.1$ months before the use of levamisole, but it was also $10.1{\pm}6.9$ month after therapy. No other side effects such as leukopenia, skin disease and other clinically significant symptoms appeared at all during therapy. Conclusion : The long-term medication of levamisole for the therapy of SDNS children is thought to be able to maintain stable remission by reducing the relapse frequency without causing severe side effects. Further study with a broader range of subjects is required to eluccidate the long-term effects of this treatment. (J. Korean Soc Pediatr Nephrol 2001;5 : 109-16)

• Applied Biological Chemistry
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• v.39 no.1
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• pp.54-59
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• 1996

Three strains of inhibitory lactic acid bacteria (No. 49, No. 61, No. 75) against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escheirchia coli(ATCC33694) and Bacillus subtilis(ATCC6633) were isolated from kimchi, and then, identified to be Lactobacillus plantarum after examinations of their biological and physiological characteristics. To investigate a possible application of these three lactobacilli in milk fermentation industry, we made yogurts and then evaluated their ${\beta}-galactosidase$ activities at various; incubation time(from 24 hrs to 72 hrs). The result of experiment was that ${\beta}-galactosidase$ activities were reached maximum at 48 hrs and that reduced gradually with the lapse of time. And the ${\beta}-galactosidase$ activity of lactobacilli, and their viable cell counts at $37^{\circ}C$ for 2 hrs under various pH conditions were investigated. ${\beta}-galactosidase$ activities of 3 strains were reduced 50% at pH 3.5, but there were no remaining activities at pH 2.5, and pH 1.5, respectively. The frequency of the survival cell of lactobacilli in yogurt were $0.12{\sim}0.75%$ at pH 2.5, $$6.3{\times}10^{-5}{\sim}2.7{\times}10^{-3}% at pH 1.5, respectively, but there was no significant difference at pH 3.5. The values of original pH, titratable acidity as lactic acid, viscosity, and viable cells of yogurts were $4.08{\sim}4.30,\;1.05{\sim}1.25%,\;1,818{\sim}2,124\;cps\;and\;7.3{\times}10^8{\sim}3.0{\times}10^9\;cfu/m{\ell}$, respectively. To estimate buffer capacity of yogurt, the volume of 1.0 N HCl to 2 unit below original pH of yogurt($100\;m{\ell}$) was $11.98{\sim}13.02\;m{\ell}$ and the volume of 1.0N NaOH to 4 unit above original pH of yogurt($100\;m{\ell}$) was $10.82{\sim}12.86\;m{\ell}.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.720-726
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• 2007

This study was performed to investigate effects of raw sea tangle products on idiopathic constipation. A total of thirty-eight women participated voluntarily in this study. They were placed into one of four groups by their total colonic transit time (TCTT) to make the four groups have the same TCTT. In the first trial, the subjects in Control group were fed 3 times of 150 mL of mineral water per day for 2 weeks, those in +Control group were fed a kind of stool softener as well as the same mineral water for 3 times, those in STT group were fed 3 times of 150 mL of sea tangle tea and those in STB group were fed 3 times of 150 mL of sea tangle beverage. After 6 weeks, a second trial was performed for another 2 weeks. Although the TCTT of the group exposed to of KolomarkTM was not significantly reduced, the subjects in STT group answered that their evacuation activities were significantly improved; evacuation frequency was increased, stool hardness was reduced, evacuation straining was lessened, stool amount was increased, incomplete sense of evacuation was lessened, and major evacuation time was improved like those in +Control group. The results imply that it is worthy to develop some products of raw sea tangle such as STT, which are effective in treating or preventing constipation.

• Journal of Music and Human Behavior
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• v.2 no.2
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• pp.33-56
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• 2005

The purpose of this study is to measure the effect of musical activities on children's aggressiveness using percussion playing through case studies and to present the therapeutic programs. Musical activities using percussion playing were organized for three aggressive children. Twenty-one small group sessions were conducted over seven weeks with 30 minutes given each session. Fourth-grade children involved in using Aggressiveness Measuring Tool for Teachers-revised by Gwak Geum-Joo(1992) was selected for case studies. Children's impulsiveness was also tested through self-test measuring tool for impulsiveness-revision of 16 questions used by Cho Hae Yeon (2001) and Lee Joo Shik (2003). As quantitative method, comparative analysis was made between the pre and post test results using measuring tools for aggressiveness and impulsiveness of children as well as between aggressive behaviors occurring in the initial stage of the first three sessions and in the latter stage of the last three sessions. Qualitative method was used at the same time to examine the effect of percussion playing on children. After the musical activities, child A showed reduced Aggressive Measuring Tool scores from 19 to 18, with child B from 23 to 19 and child C from 21 to 18. The results show that occurrence of aggressive behaviors were lowered in the post test. Impulsiveness Measuring Tool scores in the post test were decreased as well in all three children. During the music therapy programs, it was also observed that the frequency of the target behaviors in all three children has reduced more in the latter stage than the initial stage of music therapy. The qualitative findings indicate that the children experienced releasing stress through self-expression after percussion playing. These findings indicate therapeutic effectiveness of music therapy using on percussion playing in reducing aggressiveness of children as well as the effectiveness of percussion as a therapeutic intervention for aggressive children. These results can be adapted and reapplied by teachers in primary schools to approach children with behavior problems, and can present a useful therapeutic approach to therapists practicing in clinical environments.