• 한국체육학회지인문사회과학편
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• v.58 no.6
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• pp.449-459
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• 2019

The purpose of this study is to identify how postural mechanics affects postural control on balance and stability by using frequency analysis technique from the kinematic data acquired during the one leg standing posture. For this purpose, the experimental group consisted of two groups, the normal group (n=6) and the national Gymnastics group (n=6). Displacement data of CoP were analyzed by frequency analysis of rambling (RM) and trembling (TR) by FFT signal processing. As a results, there was a significant difference in evaluating the stabilization index between the two groups with the eyes open and closed one leg stnading (p <.05). The cause of the difference was found to be the output of the maximum amplitude of RM (f1) and TR (f2) (p <.05). In particular, in the low frequency RM of 8-9 Hz, which is a natural frequency of signal wave involved in postural feedback feedback, the main frequency appeared to be performs the exercise mechanism of stable brain posture control. And in the high frequency TM of 120-135 Hz, it is considered that the adaptation of the reflective muscle response is minimized to minimize posture shaking. In conclusion, this study provides evidence for the intrinsic main frequencies according to the postural control ability which affects the CNS in one leg standing.

• Journal of the Korean Society of Radiology
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• v.15 no.1
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• pp.55-61
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• 2021

In this study, microbes were collected before and after disinfection using ANIOS(ANIOSURF Premium NPC) and compared the areas where the radiological technologist and the patient frequently contacted the chest X-ray. From September 1st to September 7th, 2020. in P Hospital in Deagu, 4 region were collected in a 10×10 size using a sterile cotton swab of the transport medium, and before and after disinfection results were obtained through the colorimetric method. As a result, n the X-ray tube handle Proteus mirabilis, Staphylococcus epidermidis, Bacillus spp., Candida spp., and in the Chin region Proteus mirabilis, Enterococcu faecium, Pseudomonas aeruginosa, NTM, and in the Chest region Proteus mirabilis, Enterococcu faecium, Pseudomonas aeruginosa, and in the Palm region NTM, Candida spp. were detected, and 103 CFU(Colony Forming Unit) or more were measured. After disinfection, only X-ray tube handle was detect Bacillus spp. and more than 102 CFU was measured. Microorganisms found prior to disinfection can cause opportunistic infections, Experimental results showed that Aniosulf(0.25%) is more economical and disinfectant than ethanol(70-90%) and isopropyl alcohol(70-90%). However, further research is needed on the detection of Bacillus spp. resultingly this research is useful basic data of infection control in Radiography room and prevention secondary infections.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.603-612
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• 2022

The study aims were to evaluate a machine-learning, algorithm-based, forest biomass-estimation model to estimate subnational forest biomass and to comparatively analyze REDD+ forest reference emission levels. Time-series Landsat satellite imagery and ESA Biomass Climate Change Initiative information were used to build a machine-learning-based biomass estimation model. The k-nearest neighbors algorithm (kNN), which is a non-parametric learning model, and the tree-based random forest (RF) model were applied to the machine-learning algorithm, and the estimated biomasses were compared with the forest reference emission levels (FREL) data, which was provided by the Paraguayan government. The root mean square error (RMSE), which was the optimum parameter of the kNN model, was 35.9, and the RMSE of the RF model was lower at 34.41, showing that the RF model was superior. As a result of separately using the FREL, kNN, and RF methods to set the reference emission levels, the gradient was set to approximately -33,000 tons, -253,000 tons, and -92,000 tons, respectively. These results showed that the machine learning-based estimation model was more suitable than the existing methods for setting reference emission levels.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.1
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• pp.10-17
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• 2001

Purpose: We measured anti-H. pylori IgG in Korean elementary school children living in Shinchon area of Seoul, Korea to evaluate the influence of environmental living standards on H. pylori infection. Methods: IgG antibodies to H. pylori were measured in plasma using a commercial ELISA kit (GAP IgG Helicobacter pylori, Bio-Rad Laboratories Inc., Hercules, CA, USA). Information on environmental status such as place of birth, parental income, type of housing, number of persons in the household, parents' occupation, family history of peptic ulcer disease and gastric cancer was obtained. Statistical analysis was done by Chi-square and logistic regression test using SPSS $7.0^{TM}$ for Windows. Results: Study subjects consisted of 571 children, and the age distribution ranged from 6.0 to 13.6 years with a mean of $9.6{\pm}1.8$ years. Male-to-female ratio was 1.1:1. The seropositive rates of H. pylori infection ranged from 10.4% in children aged 6 years to 30.9% in 12 year-old group, overall 16.8%. The prevalence of H. pylori infection progressively increased with age, but there was no significant difference in seropositive rates among children in different age groups (p=0.06). Seropositive rates of anti-H. pylori IgG on the basis of gender, place of birth, parental income, type of housing, parents' occupation, family history of peptic ulcer disease and gastric cancer showed no statistically significant difference. Interestingly, however, seropositive rate of anti-H. pylori IgG showed statistical significance in relation to number of persons in the household (p=0.003; Odds ratio 1.50 by logistic regression test). Conclusion: These results suggest that number of persons in the household is the most important factor among environmental living standards, and that risk of H. pylori infection increases by increment of 1.5 times as the number of persons in the household increases by one.

• Radiation Oncology Journal
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• v.9 no.1
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• pp.27-35
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• 1991

An interstitial radiofrequency needle electrode system was constructed for interstitial heating of brain tissue. Radiofrequency electrodes with Thermotron RF 8 were tested in an agar phantom and in a normal canine brain to determine how variations in physical factors affected temperature distributions. Temperature distributions were checked after heating with 1 mm diameter needle electrode implants on the corners of 1 and 2 cm squares in a phantom and plot isotherms for various electrodes arrangement. We observed that the 1 cm square array would heat a volume with a 1.25 cm radius circular field cross section to therapeutic temperatures ($90\%$ relative SAR using Tm) and the 2 cm square array with a 1.75 cm radius rectangular field with central inhomogeneity. With 2 cm long electrode implants, we observed that the 1 cm square array would heat a 3 cm long sagittal section to therapeutic temperature ($90\%$ relative SAR using Tm). We found that radiofrequency electrodes could be selected to match the length of the heating area without affecting its performance. The histopathological changes associated with RF heating of normal canine brains have been correlated with thermal distributions. RF needle electrode heating was applied for 50min to generate tissue temperatures of $43^{\circ}C$. We obtained a quarter of the heated tissue material immediately after heating and sacrificed at intervals from $7\sim30$days. The acute stage (immediately after heating) was demonstrated by liquefactive necrosis, pyknosis of neuronal element in the gray matter and by some polymer-phonuclear leukocytes infiltration. The appearance of lipid-laden macrophages surrounding the area of liquefaction necrosis was demonstrated in all three sacrificed dogs. Mild gliosis occurring around the necrosis was demonstrated in the last sacrificed (Days 30) canine brain.

• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.13-22
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• 2005

It has been known that pulsatile flow is physiologic and more favorable to tissue perfusion than nonpulsatile flow. The purpose of this study is to directly compare the effect of pulsatile versus nonpulsatile blood flow to renal tissue perfusion in extracorporeal circulation by using a tissue perfusion measurement system. Material and Method: Total cardiopulmonary bypass circuit was constructed to twelve Yorkshire swines, weighing 20$\~ $30 kg. Animals were randomly assigned to group 1 (n=6, non pulsatile centrifugal pump) or group 2 (n=6, pulsatile T-PLS pump). A probe of the tissue perfusion measurement system $(QFlow^{TM}-500)$ was inserted into the renal pa­renchymal tissue. Extracorporeal circulation was maintained for an hour at a pump flow of 2 L/min after aortic cross-clamping. Tissue perfusion flow of the kidney was measured at baseline (before bypass) and every 10 minutes after bypass. Serologic parameters were collected at baseline and 60 minutes after bypass. Result: Baseline parameters were not different between the groups. Renal tissue perfusion flow was substantially higher in the pulsatile group throughout the bypass (ranged 48.5$\~$ 64 in group 1 vs. 65.8$\~$88.3 mL/min/100 g in group 2, p=0.026$\~$ 0.45) The difference was significant at 30 minutes bypass $(47.5{\pm}18.3\;in\;group\;1\;vs.\;83.4{\pm}28.5$ mL/min/100 g in group 2, p=0.026). Serologic parameters including plasma free hemoglobin, blood urea nitrogen, and creatinine showed no differences between the groups at 60 minutes after bypass (p=NS). Conclusion: Pulsatile flow is more beneficial to tissue perfusion of the kidney in short-term extracorporeal circulation. Further study is suggested to observe the effects to other vital organs or long-term significance.

• Journal of the Korean association of regional geographers
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• v.9 no.3
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• pp.373-384
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• 2003

This study analyses the soil loss due to cropland increase in the Hoeryeung area of northeast Korea, using Landsat images of 1987 TM and 2001 ETM, together with DTED, soil and geological maps, and rainfall data of 20 years. Items of land cover and land use were categorized as cropland, settlement, forest, river zone, and sand deposit by supervised classification with spectral bands 1, 2 and 3. RUSLE model is used for estimation of soil loss, and AML language for calculation of soil loss volumes. Fourier transformation method is used for unification of the geographical grids between Landsat images and DTED. GTD was selected from 1:50,000 topographic map. Main sources of soil losses over 100 ton/year may be the river zone and settlement in the both times of 1987 and 2001, but the image of the 2001 shows that sources areas have developed up to the higher mountain slopes. In the cropland average, increases of hight and gradient are 24m and $0.8^{\circ}$ from 1987 to 2001. In the case of new developed cropland, average increases are 75m and $2.5^{\circ}$, and highest soil loss has occurred at the elevation between 300 and 500m. The soil loss 57 ton of 1987 year increased 85 ton of 2001 year. Soil loss is highest in $30{\sim}50^{\circ}$ slope zones in both years, but in 2001 year, soil loss increased under $30^{\circ}$ zones. The size of area over 200 ton/year, indicating higher risk of landslides, have increased from $28.6km^2$ of 1987 year to $48.8km^2$ of 2001 year.

• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.103-107
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• 2012

We compared between an automated most-probable-number technique $TEMPO^{(R)}$TVC and traditional plating methods $Petrifilm^{TM}$ for estimating populations of total aerobic bacteria in various livestock products. 257 samples randomly selected in local retail stores and 87 samples inoculated with $E.$ $coli$ ATCC 25922, $Staphylococcus$ $aureus$ ATCC 12868 were tested in this study. The degree of agreement was estimated according to the CCFRA (Campden and Chorleywood Food Research Association Group) Guideline 29 and the agreement indicates the difference of two kinds methods is lower than 1 log base 10($log_{10}$). The samples of hams, jerky products, ground meat products, milks, ice creams, infant formulas, and egg heat formed products were showed above 95% in the agreement of methods. In contrast, proportion of agreement on meat extract products, cheeses and sausages were 93.1%, 92.1%, 89.1%, respectively. One press ham and five sausages containing spice and seasoning, two pork cutlets containing spice and bread crumbs, two meat extract product and two natural cheeses and one processing cheese with a high fat content, and one ice cream containing chocolate of all samples showed the discrepancy. Our result suggest that $TEMPO^{(R)}$TVC system is efficient to analyses total aerobic bacteria to compare manual method in time-consuming and laborious process except livestock products having limit of detection.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.885-894
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• 2006

The purpose of this study is focused on the development of the effective classification technique using ultra multiband of hyperspectral image. This study suggests the classification technique using canonical correlation analysis, one of multivariate statistical analysis in hyperspectral image classification. High accuracy of classification result is expected for this classification technique as the number of bands increase. This technique is compared with Maximum Likelihood Classification(MLC). The hyperspectral image is the EO1-hyperion image acquired on September 2, 2001, and the number of bands for the experiment were chosen at 30, considering the band scope except the thermal band of Landsat TM. We chose the comparing base map as Ground Truth Data. We evaluate the accuracy by comparing this base map with the classification result image and performing overlay analysis visually. The result showed us that in MLC's case, it can't classify except water, and in case of water, it only classifies big lakes. But Canonical Correlation Classification (CCC) classifies the golf lawn exactly, and it classifies the highway line in the urban area well. In case of water, the ponds that are in golf ground area, the ponds in university, and pools are also classified well. As a result, although the training areas are selected without any trial and error, it was possible to get the exact classification result. Also, the ability to distinguish golf lawn from other vegetations in classification classes, and the ability to classify water was better than MLC technique. Conclusively, this CCC technique for hyperspectral image will be very useful for estimating harvest and detecting surface water. In advance, it will do an important role in the construction of GIS database using the spectral high resolution image, hyperspectral data.

• The Journal of Korean Society for Radiation Therapy
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• v.35
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• pp.7-13
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• 2023

Purpose: In this study, we evaluated the effect of using a customized bolus on dose delivery in the treatment plan when cervical cancer protruded out of the body along with the uterus and evaluated reproducibility in patient set-up. Materials & Methods: The treatment plan used the Eclipse Treatment Planning System (Version 15.5.0, Varian, USA) and the treatment machine was VitalBeam (Varian Medical Systems, USA). The radiotherapy technique used 6 MV energy in the AP/PA direction with 3D-CRT. The prescribed dose is 1.8 Gy/fx and the total dose is 50.4 Gy/28 fx. Semiflex TM31010 (PTW, Germany) was used as the ion chamber, and the dose distribution was analyzed and evaluated by comparing the planned and measured dose according to each position movement and the tumor center dose. The first measurement was performed at the center by applying a customized bolus to the phantom, and the measurement was performed while moving in the range of -2 cm to +2 cm in the X, Y, and Z directions from the center assuming a positional error. It was measured at intervals of 0.5 cm, the Y-axis direction was measured up to ±3 cm, and the situation in which Bolus was set-up incorrectly was also measured. The measured doses were compared based on doses corrected to CT Hounsfield Unit (HU) 240 of silicon instead of the phantom's air cavity. Result: The treatment dose distribution was uniform when the customized bolus was used, and there was no significant difference between the prescribed dose and the actual measured value even when positional errors occurred. It was confirmed that the existing sheet-type bolus is difficult to compensate for irregularly shaped tumors protruding outside the body, but customized Bolus is found to be useful in delivering treatment doses uniformly.