• Journal of the Korean Geotechnical Society
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• v.26 no.7
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• pp.49-58
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• 2010

This paper presents experimental results of a series of 1-g shaking table model tests performed on end-bearing single piles and pile groups to investigate the effect of particle size on the dynamic behavior of soil-pile systems. Two soil-pile models were tested twice: first using Jumoonjin sand, and second using Australian Fine sand. In the case of single-pile models, the lateral displacement was almost within 1% of pile diameter which corresponds to the elastic range of the pile. The back-calculated p-y curves show that the subgrade reaction of the Jumoonjin-sand-model ground was larger than that of the Australian Fine-sand-model ground at the same displacement. This phenomenon means that the stress-strain behavior of Jumoonjin sand was initially stiffer than that of Australian Fine sand. This difference was also confirmed by resonant column tests and compression triaxial tests. And the single pile p-y backbone curves of the Australian fine sand were constructed and compared with those of the Jumoonjin sand. As a result, the stiffness of the p-y backbone curves of Jumunjin sand was larger than those of Australian fine sand. Therefore, using the same p-y curves regardless of particle size can lead to inaccurate results when evaluating dynamic behavior of soil-pile system. In the case of the group-pile models, the lateral displacement was much larger than the elastic range of pile movement at the same test conditions in the single-pile models. The back-calculated p-y curves in the case of group pile models were very similar in both sands because the stiffness difference between the Jumoonjin-sand-model ground and the Australian Fine-sand-model ground was not significantly large at a large strain level, where both sands showed non-linear behavior. According to a series of single pile and group pile test results, the evaluation group pile effect using the p-multiplier can lead to inaccurate results on dynamic behavior of soil-pile system.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.130-136
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• 2006

Purpose : The purpose of this study is to confirm the epidemiologic change of the causative organisms of neonatal and pediatric bacterial meningitis in Korea. And we tried to evaluate the risk factors correlated with prognosis which was available on the day of admission. Methods : Retrospectively, we reviewed the medical records of 57 patients admitted for bacterial meningitis at six hospitals affiliated with Catholic Medical Center for 6 years(Jan. 2000~Dec. 2005). Results : 22 cases(38.6%) of them were neonates under 28 days and 35 cases were infants and children ; 16 cases(28.1%), under 1 year ; 6 cases(10.5%), under 5 years ; 13 cases (22.8%), under 15 years. In neonates, 16 cases(72.7%) were caused by group B streptococcus (GBS). In infants and children, S. pneumoniae(25.7%), H. influenzae type b(Hib)(22.8%) and N. meningitidis(22.8%) were common cause of bacterial meningitis in order. In the informations available on the day of admission, weight deficit for age under 3 percentile, increased CRP level and decreased glucose level of CSF were related to poor prognosis(P<0.05). Conclusion : GBS became a leading cause of neonatal bacterial meningitis. Though, pneumoccocal, Hib and meningococcal meningitis were confirmed as major causes of bacterial meningitis. The routine immunization of pneumococcal and Hib vaccines will be considered, and it is necessary to introduce meningococcal vaccines to our country in the future.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.29-36
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• 2007

This study was carried out to develop a water quality simulation model for the evaluation of an ungauged watershed. For this purpose, the WASP5 model was selected and modified. The model consists of three sub-models, LOAD-M, DYN-M, and EUT-M. LOAD-M, an empirical model, estimates runoff loadings using point and non-point source data of villages. The Geum River Estuary watershed was selected to calibrate and verify the Modified-WASP5. The LOAD-M model was established using field data of water quality and quantity at the gauging stations of the watershed and was applied to the ungauged watersheds, taking the watershed properties into consideration. The result of water quality simulation using Modified-WASP5 shows that the observed average BOD data from Gongju and Ganggyeong were 2.6 mg/L and 2.8 mg/L, and the simulated data were 2.5 mg/L and 2.4 mg/L, respectively. Generally, simulation results were in good agreement with the observed data. This study focused on formulating an integrated model for evaluating ungauged watersheds. Even though simulation results varied slightly due to limited availability of data, the model developed in this study would be a useful tool for the assessment and management of ungauged watersheds.

• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.322-331
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• 1995

Introduction: This study was performed to evaluate the diagnostic usefulness of simultaneous determination of 3 tumor markers {serum carcinoembryonic antigen(CEA), squamous cell carcinoma antigen (SCC Ag) and neuron specific enolase(NSE)} in lung cancer patients. Method: In 113 patients with primary lung cancer(70 with squamous cell carcinoma, 30 with adenocarcinoma, 13 with small cell carcinoma) and 103 patients with benign lung diseases, serum CEA and NSE were measured by enzyme immunoassay, and SCC Ag was measured by microparticle enzyme immunoassay. Results: 1) The mean serum levels of 3 tumor markers were significantly higher in lung cancer groups than benign lung disease groups respectively(p=0.001). 2) In squamous cell carcinoma, the SCC Ag was elevated in 67%, in adenocarcinoma CEA was elevated in 77% and in small cell carcinoma NSE was elevated in 77%, but there were no significant differences according to the stage of each cancer cell types. 3) CEA was the most sensitive marker, but nonspecific to cancer types. SCC Ag was less sensitive than other markers, but more specific toward squamous cell carcinoma, and NSE was more specific to primary lung cancer. 4) As the number of positive tumor markers was increased, the relative possibility of lung cancer was also increased. If two markers were positive, it increased to 77%, and if three markers were positive it increased to 90%. Conclusion: The simultaneous measurement of serum CEA, SCC Ag and NSE would provide additional information for the diagnosis of lung cancer.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.803-811
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• 2021

In this study, the exposure amount of IASCC test worker was evaluated by applying the process simulation technology. Using DELMIA Version 5, a commercial process simulation code, IASCC test facility, hot cells, and workers were prepared, and IASCC test activities were implemented, and the cumulative exposure of workers passing through the dose-distributed space could be evaluated through user coding. In order to simulate behavior of workers, human manikins with a degree of freedom of 200 or more imitating the human musculoskeletal system were applied. In order to calculate the worker's exposure, the coordinates, start time, and retention period for each posture were extracted by accessing the sub-information of the human manikin task, and the cumulative exposure was calculated by multiplying the spatial dose value by the posture retention time. The spatial dose for the exposure evaluation was calculated using MCNP6 Version 1.0, and the calculated spatial dose was embedded into the process simulation domain. As a result of comparing and analyzing the results of exposure evaluation by process simulation and typical exposure evaluation, the annual exposure to daily test work in the regular entrance was predicted at similar levels, 0.388 mSv/year and 1.334 mSv/year, respectively. Exposure assessment was also performed on special tasks performed in areas with high spatial doses, and tasks with high exposure could be easily identified, and work improvement plans could be derived intuitively through human manikin posture and spatial dose visualization of the tasks.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.1
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• pp.44-49
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• 2017

Purpose Radiation exposure management has been strictly regulated for the radiation workers, but there are only a few studies on potential risk of radiation exposure to non-radiation workers, especially nurses in a general ward. The present study aimed to estimate the exact total exposure of the nurse in a general ward by close contact with the patient undergoing nuclear medicine examinations. Materials and Methods Radiation exposure rate was determined by using thermoluminescent dosimeter (TLD) and optical simulated luminescence (OSL) in 14 nurses in a general ward from October 2015 to June 2016. External radiation rate was measured immediately after injection and examination at skin surface, and 50 cm and 1 m distance from 50 patients (PET/CT 20 pts; Bone scan 20 pts; Myocardial SPECT 10 pts). After measurement, effective half-life, and total radiation exposure expected in nurses were calculated. Then, expected total exposure was compared with total exposures actually measured in nurses by TLD and OSL. Results Mean and maximum amount of radiation exposure of 14 nurses in a general ward were 0.01 and 0.02 mSv, respectively in each measuring period. External radiation rate after injection at skin surface, 0.5 m and 1 m distance from patients was as following; $376.0{\pm}25.2$, $88.1{\pm}8.2$ and $29.0{\pm}5.8{\mu}Sv/hr$, respectively in PET/CT; $206.7{\pm}56.6$, $23.1{\pm}4.4$ and $10.1{\pm}1.4{\mu}Sv/hr$, respectively in bone scan; $22.5{\pm}2.6$, $2.4{\pm}0.7$ and $0.9{\pm}0.2{\mu}Sv/hr$, respectively in myocardial SPECT. After examination, external radiation rate at skin surface, 0.5 m and 1 m distance from patients was decreased as following; $165.3{\pm}22.1$, $38.7{\pm}5.9$ and $12.4{\pm}2.5{\mu}Sv/hr$, respectively in PET/CT; $32.1{\pm}8.7$, $6.2{\pm}1.1$, $2.8{\pm}0.6$, respectively in bone scan; $14.0{\pm}1.2$, $2.1{\pm}0.3$, $0.8{\pm}0.2{\mu}Sv/hr$, respectively in myocardial SPECT. Based upon the results, an effective half-life was calculated, and at 30 minutes after examination the time to reach normal dose limit in 'Nuclear Safety Act' was calculated conservatively without considering a half-life. In oder of distance (at skin surface, 0.5 m and 1 m distance from patients), it was 7.9, 34.1 and 106.8 hr, respectively in PET/CT; 40.4, 199.5 and 451.1 hr, respectively in bone scan, 62.5, 519.3 and 1313.6 hr, respectively in myocardial SPECT. Conclusion Radiation exposure rate may differ slightly depending on the work process and the environment in a general ward. Exposure rate was measured at step in the general examination procedure and it made our results more reliable. Our results clearly showed that total amount of radiation exposure caused by residual radioactive isotope in the patient body was neglectable, even comparing with the natural radiation exposure. In conclusion, nurses in a general ward were much less exposed than the normal dose limit, and the effects of exposure by contacting patients undergoing nuclear medicine examination was ignorable.

• Clinical and Experimental Pediatrics
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• v.48 no.3
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• pp.298-305
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• 2005

Purpose : We performed this study to evaluate the mean serum levels of insulin-like growth factor (IGF)-I, insulin-like growth factor binding protein(IGFBP)-2 and IGFBP-3 in healthy Korean children according to age and sex. Methods : Ninety two healthy children, consisting of 42 boys and 50 girls, were classified into five groups according to age : neonate; infancy; early childhood; late childhood; and adolescence. We measured serum levels of IGF-I, IGFBP-2 and IGFBP-3 by enzyme-linked immunosorbent assay(ELISA) and analysed the serum levels according to sex and age group. Results : For boys, the mean serum levels of IGF-I(ng/mL) in neonate, infancy, early childhood, late childhood and adolescence were $41.1{\pm}3.6$, $70.9{\pm}33.7$, $103.5{\pm}97.2$, $89.8{\pm}46.5$ and $51.4{\pm}27.8$, respectively. Those of IGFBP-2(ng/mL) were $8.2{\pm}3.4$, $5.8{\pm}0.4$, $9.3{\pm}4.0$, $9.5{\pm}1.1$ and $7.0{\pm}0.5$, respectively. Those of IGFBP-3(ng/mL) were $559.2{\pm}215.2$, $1,333.3{\pm}692.5$, $2,254.6{\pm}1,513.8$, $2,447.1{\pm}1,464.2$, $1,533.6{\pm}807.4$, respectively. For girls, the mean serum levels of IGF-I(ng/mL) according to five age groups were $53.3{\pm}9.5$, $99.3{\pm}45.8$, $69.6{\pm}51.1$, $106.2{\pm}67.0$ and $145.1{\pm}127.8$, respectively. Those of IGFBP-2 (ng/mL) were $9.1{\pm}7.4$, $5.3{\pm}0.9$, $6.9{\pm}2.0$, $10.5{\pm}3.0$ and $7.9{\pm}1.3$, respectively. Those of IGFBP-3(ng/mL) were $858.2{\pm}433.4$, $1,834.8{\pm}851.3$, $1,404.3{\pm}570.2$, $2,203.5{\pm}899.4$ and $2,029.3{\pm}1,316.7$, respectively. There were significant positive correlations observed between IGF-I and IGFBP-3 levels(r=0.589, P=0.000). Conclusion : IGF-I and IGFBP-3 levels increased as children get older. The peak level of IGFBP-3 was observed in late childhood for both boys and girls, suggesting a current trend of children reaching peak growth velocity before adolescence. The IGFBP-2 level was higher in neonates compare to infancy, suggesting that IGFBP-2 is an important substance for fetal growth.

• Childhood Kidney Diseases
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• v.13 no.2
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• pp.235-241
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• 2009

Purpose : The purpose of this study was to determine the clinical value of bicarbonate gap (BG) in acute gastroenteritis by comparison of clinical manifestations and laboratory findings. Methods : We retrospectively analyzed 135 patients who had acute gastroenteritis. We classified them into two groups: $BG{\leq}-5$ (group A), BG>-5 (group B). We made a comparative study for clinical manifestations, serum electrolyte, albumin, protein, blood urea nitrogen (BUN), creatinine, anion gap (AG), delta anion gap (${\Delta}AG$) and delta bicarbonate (${\Delta}HCO_3{^-}$) between the two groups. Results : The duration of hospitalization and diarrhea was significantly longer in group A than group B. In laboratory findings, serum sodium, serum total $CO_2$, total protein, $AG_{corrected}$ and ${\Delta}AG$ were lower in group A than group B. ${\Delta}HCO_3{^-}$ and chloride were higher in group A than group B. Conclusion : BG may be a sensitive predictor enough to access the severity of acute gastroenteritis.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.331-338
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• 1996

Background : Lung cancer continues to be the leading cause of cancer death in the United States and it's incidence has been rapidly increasing in Korea, too. The overall cure rate for non-small cell lung cancer(NSCLC) is approximately 10%, and the cure is generally achieved by surgery. Unfortunately, however, less than 15% of all patients and less than 25% of those who present with localized disease are candidates for curative surgical resection. So preoperative staging evaluation followed by curative resection has a major role in determining the long tenn prognosis of NSCLC patients. Therefore, we have conducted this study to compare pre-operative and post-operative staging and the long-tenn relapse-free survival rates in NSCLC patients according to its stage. Methods : We analyzed the medical records of 217 NSCLC patients who were operated on for curative resection in Seoul National University Hospital, retrospectively. Among them, 170 patients who were completely resected were selected to determine the long term relapse-free survival rates. Results : Among 217 NSCLC patients, men were 157 and women were 30. The median age was 58 and the difference between men and women was not found. The discrepancy rate between preoperative and postoperative staging was 40.1%. Its major cause was due to the difference of nodal staging. The 3-year relapse-free survival rates were 73%, 53% and 48% in stage I, II and IIIa, respectively. There was no difference of relapse-free duration in recurred patients according to the stage or histologic types. Conclusion : The postoperative pathologic staging determines the long tenn prognosis of patients with NSCLC after surgery, but current preoperative clinical staging can not predict the postoperative pathologic staging correctly. So the improved modality of staging system is required to predict the pathologic staging more correctly.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.150-156
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• 2003

Tricuspid regurgitation has been considered as a secondary lesion when it is combined with left valvular heart diseases. However, there have been some reports which show that tricuspid regurgitation keeps going and results in congestive heart failure even after a successful operation for left valvular heart disease. So far, there are no definite operation indications and predictive factors for the tricuspid re-gurgitation which is resulted from the left sided valvular heart disease. We designed this study to evaluate the effects of pulmonary artery pressure and left ventricular ejection fraction on the prognosis of tricuspid regurgitation, and to make an operation indication for the patients with secondary tricuspid regurgitation. Material and Method: We reviewed the medical records of patients who underwent surgery for the left sided valvular heart disease with tricuspid regurgitation and were followed for more than 1 year with echocardiograms. There was a total of 114 cases. We compared the grades of tricuspid regurgitations and pulmonary artery pressures and left ventricular ejection fractions on the basis of echocardiograms which were checked preoperatively and on the last follow up. Result: There were 43 cases of tricuspid an-nuloplasty. In these patients, the grades of tricuspid regurgitations were improved in 42 cases (97.7%). But in 71 cases without annuloplasty, 29 cases (41%) were improved, 32 cases (45%) had no change, and 29 cases (14%) were aggravated. This finding shows significant differences in the prognoses of tricuspid regur-gitations between the two groups (p<0.05). There was no difference in pulmonary artery pressures and ejection fractions between the patients who showed progression of tricuspid regurgitations and those who didn't (p > 0.05). The improvements of tricuspid regurgitations are not statistically related to the changes of pulmonary artery pressures or left ventricular ejection fractions. Conclusion: This study shows that it is impossible to predict the prognoses of tricuspid regurgitations with preoperative pulmonary artery pressures or left ventricular ejection fractions. Also, the excellent results of tricuspid annuloplasty is proven in controlling the secondary tricuspid regurgitations. Therefore, when tricuspid regurgitation is detected preoperatively, the procedures to correct the tricuspid regurgitation at the time of the operation for the left-sided valvular heart disease must be considered positively, regardless of the grades of tricuspid regurgitations, to prevent sig-nificant tricuspid regurgitation that may develop later.