• Journal of the Korean Geotechnical Society
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• v.38 no.5
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• pp.5-17
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• 2022

A pile is a type of medium for constructing superstructures in weak geotechnical conditions. A pretensioned spun high-strength concrete (PHC) pile is composed of high-strength concrete with a specified strength greater than 80 MPa. Therefore, it has advantages in resistance to axial and bending moments and quality control and management since it is manufactured in a factory. However, the skin friction of a pile, which accounts for a large portion of the pile bearing capacity, is only approximated using empirical equations or standard penetration test (SPT) N-values. Particularly, there are some poor research results on the pile-soil interface under the seismic loads in Korea. Additionally, some studies do not consider geoenvironmental elements, such as groundwater pH values. This study performs sets of cyclic simple shear tests using submerged concrete specimens for 1 month to consider pH values of groundwater and clay specimens composed of kaolinite to generate a pile-soil interface. 0.2 and 0.4 MPa of normal stress conditions are considered in the case of pH values. The disturbed state concept is employed to express the dynamic behavior of the interface, and the disturbed function parameters are newly suggested. Consequently, the largest disturbance increase under basic conditions is observed, and an early approach to the failure under low normal stress conditions is presented. The disturbance function parameters are also suggested to express this disposition quantitatively.

• Journal of the Korean Society of Radiology
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• v.82 no.1
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• pp.173-181
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• 2021

Purpose To evaluate the ability of the Hounsfield unit (HU) measurement of the femoral neck during multidetector computed tomography (MDCT) for assessing osteoporosis compared with dual-energy X-ray absorptiometry (DXA). Materials and Methods Forty-two patients with femoral neck fractures who underwent MDCT and DXA from July to December 2016 were included in this study. HU measurements were made of the cancellous portions of the normal contralateral femoral neck on MDCT. Bone mineral density (BMD) and T-scores were obtained at the femur DXA. Correlations of HU values with BMD and T-scores were analyzed using Spearman's correlation test. Results The mean BMD and T-score of the femoral neck were 0.650 g/cm² and -2.4, respectively. The mean HU values for the normal, osteopenia, and osteoporosis groups were 131.9, 98.9, and 41.3, respectively. HU values at the femoral neck were positively correlated with BMD (r² = 0.670; p < 0.001) and T-scores (r² = 0.676; p < 0.001). Conclusion The HU values of the femoral neck on MDCT are significantly correlated with BMD and T-scores of femur DXA. The HU values may serve as a diagnostic tool for the screening of regional bone quality when MDCT is performed for other reasons.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.127-134
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• 2008

Purpose: The purpose of this study was to determine the expected values of accommodation and vergence system for analysis of binocular vision. Methods: Seventy three healty subjects without past history of eye disease were selected for this study, Patients showing clinical binocular anomalies including manifest squint and intermittent heterotropia were excluded and data was collected on 54 patients(mean age, 25.3${\pm}$2.7 year). Near point of convergence, distance and near phoiras were measured based on objective deviation angle. And then AC/ A ratio, relative accommodation were measured and all of the data were compared with the Morgan's expected values. Results: The values of distance and near heterophoria were 1.24${\pm}$2.72${\Delta}$ and 2.70${\pm}$4.91${\Delta}$ respectively and the gradient AC/A ratio was 3.92${\pm}$2.17${\Delta}$/D which were all about the same compared with the Morgan's expected values. The values of distance negative fusional convergence was same, however, distance positive fusional convergence was 7${\Delta}$ greater than the Morgan's one. There were no significant differences in the range values of both near vergences while the range of distance vergence was relatively larger than the Morgan's one. Positive relative accommodation was +0.37D greater and negative relative accommodation was -0.63D greater than the Morgan's values. Conclusions: The findings in this study appear that the Morgan's expected values have a possibilities of including considerable proximal convergence value. In comparison with Morgan's values, Korean's normal expected values have much different values of especially BO limit, so if the Morgan's values are directly applied to binocular vision analysis for Korean people, it may lead to an inaccurate binocular vision diagnosis. This results can be used to diagnose the accommodation and vergence system of Korean normal young adults.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.654-661
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• 1999

Background : The upper respiratory tract is the primary target organ of various airborne pollutants and is easily accessible part of the respiratory tract, and also is the predominant structure where chronic cough originates. The nasal peak inspiratory flow(PIFn), which is the peak inspiratory flow via nose with nasal mask and spirometry, could be a reliable parameter of nasal obstruction. The validity of PIFn has been evaluated in several studies by assessing the correlation between PIFn measurements and other parameters of nasal air flow. This study was designed to show the reproducibility of PIFn, the difference of PIFn between patients with chronic cough and normal subjects, and the usefulness of PIFn in the evaluation of nasal obstruction in patients with chronic cough. Methods : PIFn was measured by spirometry with nasal mask, twice a day for 3 consecutive days in 7 young normal subjects to evaluate validity of the test. In 32 patients with chronic cough and 25 age-matched normal subjects, PIFn and pulmonary function test($FEV_1$, $FEV_1%$ pred, FVC, and FVC% pred) were measured at first visiting. Results : Values of PIFn, $FEV_1$, and FVC were nearly constant in 7 young normal adults. Patients with chronic cough were 32 (14 males and 18 females) and the mean age was $41.4{\pm}15.9$ years. Normal subjects were 32(22 males and 10 females) and the mean age was $39.8{\pm}18.6$ years. There was no significant difference of age and pulmonary function test between patients with chronic cough and normal subjects(p<0.05). The PIFn values in patients with chronic cough was significantly lower than those of normal subjects($2.25{\pm}0.68\;L/sec$ vs. $2.75{\pm}1.00\;L/sec$ ; p=0.02). The postnasal drip syndrome(PNDS) comprised the majority of patients with chronic cough(27). The PIFn in patients with PNDS was significantly lower than that of normal subjects (mean$\pm$SD ; $2.18{\pm}0.66$ vs. $2.75{\pm}1.00\;L/sec$, p=0.006). Conclusion : There was a significant difference of PIFn between patients with chronic cough and normal subjects. Among the patients with chronic cough, patients with PNDS showed the most significant difference with normal subjects in PIFn. The PIFn could be a useful parameter of nasal obstruction in patients with chronic cough, especially in patients with PNDS.

• The korean journal of orthodontics
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• v.27 no.4 s.63
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• pp.643-659
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• 1997

For the total treatment of skeletal malocclusions, 3-dimensional evaluation and diagnosis are essential. Although anteroposterior discrepancies can be evaluated through various methods, the satisfactory methods for evaluations of facial asymmetry and transverse discrepancies are yet to be found. The adequate diagnosis and treatment of transverse discrepancies may be more important in the maintenance of functional occlusion as well as for the stability of results obtained from orthognathic surgery than the anteroposterior or vertical discrepancies. Since the soft tissue effects from the transverse discrepancies may not be pronounced, especially when combined with anteroposterior or vertical discrepancies which have prominent characteristics, the differentiation of their effects may be difficult from visual inspection alone. Therefore it is essential that the normal facial proportions would be established from the posteroanterior cephalometry as a reference for the accurate diagnosis and treatment. The present study evaluates 76 subjects from Yonsei University freshmen with normal facial symmetry and occlusion. Posteroanterior cephalograms were taken from the subjects and the normal values and facial proportions are obtained. The results are as follows. 1. The transverse and vortical values from posteroanterior cephalometry and their ratio, with means and standard deviations are calculated. 2. The ratio of vertical values to transverse values is 0.837 (male 0.836, female 0.841). 3. The Proportion of maxillary and mandibular widths is 0.747 (male 0.745, female 0.752), with statistically significant correlation. 4. Various degree of significant correlations are observed in the following craniofacial widths; (Cranial width, Bizygomaticofrontal suture width, Facial width, Maxillary width, Upper & Lower Intermolar width, Mandibular width). 5. Although the facial height as well as other line measurements increase as the facial widths increase, angle measurement ($Bj\ddot{o}rk$ Sum, Mandibular Plane Angle, Gonial Angle), decreases and posterior to anterior facial height ratio increases, therefore indicating the tendency for a brachycephalic facial type. These results may be used as references for the treatment planning in orthognathic and orthodontic treatments for the dentofacial deformity patients.

• Tuberculosis and Respiratory Diseases
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• v.39 no.2
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• pp.141-149
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• 1992

In order to establish predicted normal values of volume of isoflow($V_{iso}\dot{V}$), $V_{iso}\dot{V}$ were measured in a total 234 healthy adults, consisting of 78 male nonsmokers, 108 male smokers and 48 female nonsmokers. The volumes of isoflow were determined through analysis of maximal expiratory flow volume curves recorded with a mixture of 80% helium and 20% oxygen(He-$O_2$ gas) following one(1VC) and three vital capacity(3VC) maneuver and with room air. Based upon the correlation of the observed values of the parameters to age and physical characteristics, the following regression formulars for the prediction of the parameters, using age in year(A) as a variable, were obtained. 1VC method ($V_{iso}\dot{V}_1$) Male smoker : 0.614A+2.347 Male nonsmoker : 0.370A-2.792 Female nonsmoker : 0.588A-2.459 3VC method ($V_{iso}\dot{V}_3$) Male smoker : 0.467A+1.696 Male nonsmoker : 0.288A-1.538 Female nonsmoker : 0.367A-0.114.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.2
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• pp.158-165
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• 2016

The purpose of this study was to analyze photoplethysmographic waveforms from pulse oximeter using raw data of red and infrared light and investigate the reference values of parameters (Height, Width50, Maximum slope, Minimum slope, Area) for evaluating pulpal blood flow in maxillary central incisors with normal pulp vitality in children. The study was performed in 30 pediatric patients, aged 7-16 years old, using pulse oximeter (MEKICS Co., Ltd, Korea) combined with a custom-made sensor. The raw data was obtained and recorded by custom-made software and analyzed by LabChart (v.7.3, ADInstruments, Germany) offline. In this study, we analyzed photoplethysmographic waveforms from pulse oximeter applied to maxillary central incisor for assessment of pulpal blood flow and suggested several reference values of young permanent maxillary central incisor with normal pulp. On average, the waveform of red light was higher, stiffer and wider than that of infrared light. Future studies about reference values for other normal teeth and the teeth with impaired pulp vitality are needed.

• Journal of Sericultural and Entomological Science
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• v.2
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• pp.73-81
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• 1962

This treatise is to analyze the chemical components in the mulberry varieties which are cultured in Korea and to estimate the nutritive values for them. Some of these varieties were developed lately in this country just by the general breeding aspect of mulberry leaf producing and silkworm raising experimentation without analysing the nutritive values of them which may be differed by various culturing condition. This work will be helpful for the improvement of mulberry varieties and the correct judgement of them. The varieties used for the analysis are as followings; A. Morus bombycis Koridz species. 1.Ichi-Hei. 2. Shimano-Uchi B. Morus alba L. species. 3. Kairyo-Nezumigaeshi. 4. Suwon-Daeyop. 5. Suwon No. 3. 6. Suwon No. 4. 7. Yongchon-Chuwoo. C. Morus Ihou (Ser.) Koidz species. 8. Ro-Soh. The specimens were eventually taken under the air and soil dry season because of the rain shortage during the sampling period and the results are found as a rather different from the normal specimen under the normal climate. Therefore, this treatise will be an important report on a special culturing condition and the nutritive values by the mulberry varieties, and still comparable because they were grown under the same condition. The individual conclusions are; 1. Yongchon-Chuwoo which was originated in this country, was found as an important variety for this country from the aspect of mulberry nutritive value and leaf producing amount, and it is believed that this is the best suitable variety for the soil of Korea. 2. Ichi-Hei occupies the better situation as well as Yongchon-Chuwoo from the nutritive criticizing even though it was originated in Japan. 3. The lately developed Suwon No.3 and No.4 are best from the leaf producing point of view, but they are not found such a good varieties from the nutritive aspect. The result may be happened as poor because they were cut before spring sprout started. 4. Ro-Soh which was normally recognized as a poor variety, was also found as a poor nutritive and leaf producing variety. 5. The crude protein and crude fat components in the mulberry leaves decreased as the leaf maturity was progressed, but the crude fiber and crude ash components increased reversively in general view. It was also found that there were some specific changing nature by the mulberry varieties and could not rule them by just one conclusion. 6. During the air and soil dry season, the ash component increases but the hydrocarbon and moisture contents decrease considerably, and which resulted to the increase of mulberry hardness ratio and the decrease of sugar-protein ratio, eventually it causes the decrease of the nutritive value. It was also found that Ichi-Hei, Ro-Soh, and Suwon No. 3 had a strong recovering nature to their normal nutritive condition after raining. 7. Mulberry is of course a rich calorie diet, and is calculated as 50 to 60 Cal. per gram.

• The Korean Journal of Nuclear Medicine
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• v.23 no.2
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• pp.155-163
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• 1989

Regional cerebral perfusion was evaluated in 15 normal controls by single photon emission computed tomography using $^{99m}Tc$ HM-PAO. For quantitative analysis, 13 pairs of homologous region of interest (ROI) were drawn on three transverse slices matching the vascular territories and cerebral cortices, and normal values of 3 semiqunatitative indices including 'Right to left ratio'(R/L ratio), 'Regional index'(RI), and 'Region to cerebellum ratio'(R/cbll ratio) were calculated. Mean values of R/L ratios of homotogous regions were ranged from 0.985 to 1.023, and mean ${\pm}2$ s.d. of all regions did not exceed 11% of mean. Significant difference of RIs (mean count per voxel of a ROI/mean count per voxel of total ROIs) between regions were found (p<0.001) with highest values in occipital cortex and cerebellum. After attenuation correction, RIs in deep gray, cranial portion of anterior cerebral artery and vascular territories in the 2nd slice increased significantly (p < 0.05-0.001), but vise versa in other ROIs. Region to cerebellum ratios also showed regional difference similar to RIs.

• Journal of Biomedical Engineering Research
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• v.27 no.5
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• pp.203-209
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• 2006

The aim of this study is to investigate the feasibility of ex vivo MR diffusion tensor imaging technique in order to observe the diffusion-contrast characteristics of human gastric tissues. On normal and pathologic gastric tissues, which have been fixed in a polycarbonate plastic tube filled with 10% formalin solution, laboratory made 3D diffusion tensor Turbo FLASH pulse sequence was used to obtain high resolution MR images with voxel size of $0.5{\times}0.5{\times}0.5mm^3\;using\;64{\times}32{\times}32mm^3$ field of view in conjunction with an acquisition matrix of $128{\times}64{\times}64$. Diffusion weighted- gradient pulses were employed with b values of 0 and $600s/mm^2$ in 6 orientations. The sequence was implemented on a clinical 3.0-T MRI scanner(Siemens, Erlangen, Germany) with a home-made quadrature-typed birdcage Tx/Rx rf coil for small specimen. Diffusion tensor values in each pixel were calculated using linear algebra and singular value decomposition(SVD) algorithm. Apparent diffusion coefficient(ADC) and fractional anisotropy(FA) map were also obtained from diffusion tensor data to compare pixel intensities between normal and abnormal gastric tissues. The processing software was developed by authors using Visual C++(Microsoft, WA, U.S.A.) and mathematical/statistical library of GNUwin32(Free Software Foundation). This study shows that 3D diffusion tensor Turbo FLASH sequence is useful to resolve fine micro-structures of gastric tissue and both ADC and FA values in normal gastric tissue are higher than those in abnormal tissue. Authors expect that this study also represents another possibility of gastric carcinoma detection by visualizing diffusion characteristics of proton spins in the gastric tissues.