• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.225-228
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• 2007

This paper presents a geostatistical methodology to model local uncertainty in spatial estimation of sediment grain size with high-resolution remote sensing imagery. Within a multi-Gaussian framework, the IKONOS imagery is used as local means both to estimate the grain size values and to model local uncertainty at unsample locations. A conditional cumulative distribution function (ccdf) at any locations is defined by mean and variance values which can be estimated by multi-Gaussian kriging with local means. Two ccdf statistics including condition variance and interquartile range are used here as measures of local uncertainty and are compared through a cross validation analysis. In addition to local uncertainty measures, the probabilities of not exceeding or exceeding any grain size value at any locations are retrieved and mapped from the local ccdf models. A case study of Baramarae beach, Korea is carried out to illustrate the potential of geostatistical uncertainty modeling.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4659-4663
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• 2023

The use of iodine S values derived using the International Commission Radiological Protection (ICRP) phantoms may introduce significant bias in internal dosimetry for Koreans due to anatomical variability. In the current study, we produced an extensive dataset of Korean S values for selected five iodine radioisotopes (I-125, I-129, I131, I-133, and I-134) for use in radiation protection. To calculate S values, we implemented Monte Carlo simulations using the Mesh-type Reference Korean Phantoms (MRKPs), developed in a high-quality/fidelity mesh format. Noticeable differences were observed in S value comparisons between the Korean and ICRP reference phantoms with ratios (Korean/ICRP) widely ranging from 0.16 to 6.2. The majority of S value ratios were lower than the unity in Korean phantoms (interquartile range = 0.47-1.28; mean = 0.96; median = 0.69). The S values provided in the current study will be extensively utilized in iodine internal dosimetry for Koreans.

• Clinics in Shoulder and Elbow
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• v.26 no.3
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• pp.222-230
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• 2023

Background: Distal biceps tendon repairs are commonly performed using open techniques. A minimally invasive distal biceps tendon repair technique using a speculum and hooded endoscope was developed to improve visualization, reduce soft-tissue dissection, and minimize complications. This paper describes the technique and reports the outcomes of 75 minimally invasive distal biceps tendon repairs. Methods: The operation reports and outcomes of 75 patients who underwent distal biceps tendon repair using this technique between 2011 and 2021 were retrospectively reviewed. Results: Median time to follow-up was 12 months (interquartile range [IQR], 6-56 months). Primary outcomes were function as measured by the Disabilities of Arm, Shoulder and Hand Score (DASH) questionnaire, and rate of complications. Median DASH score was 1.7 of 100 (IQR, 0-6.8). There were 2 of 75 (2.7%) re-ruptures of the distal tendon. There were no cases of vascular injury, proximal radius fracture, or posterior interosseous nerve, median, or ulnar nerve palsy. Conclusions: In this series, minimally invasive distal biceps repair was safe and effective with a low rate of major complications. Recovery of function, as indicated by low DASH scores, was satisfactory, and inconvenience during recovery was minimized. Level of evidence: IV.

• Journal of Korea Water Resources Association
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• v.45 no.3
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• pp.275-290
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• 2012

In this study, we have developed an optimal time distribution model through extraction of peaks over threshold (POT) series. The median values for annual maximum rainfall dataset, which are obtained from the magnetic recording (MMR) and the automatic weather system(AWS) data at Seoul meteorological observatory, were used as the POT criteria. We also suggested the improved methodology for the time distribution of extreme rainfall compared to Huff method, which is widely used for time distributions of design rainfall. The Huff method did not consider changing in the shape of time distribution for each rainfall durations and rainfall criteria as total amount of rainfall for each rainfall events. This study have suggested an extracting methodology for rainfall events in each quartile based on interquartile range (IQR) matrix and selection for the mode quartile storm to determine the ranking cosidering weighting factors on minutely observation data. Finally, the optimal time distribution model in each rainfall duration was derived considering both data size and characteristics of distribution using kernel density function in extracted dimensionless unit rainfall hyetograph.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.625-637
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• 2003

This study was performed to examine the relationship between air pollution exposure and mortality in Seoul for the years of 1998∼2001. Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of seasonal trend, air temperature, humidity, and day of the week as confounders in a nonparametric approach. Daily death counts were associated with CO (current day),O$_3$ (current day), PM$_{10}$ (current day), NO$_2$ (1 day before), SO$_2$ (1 day before). Increase of 41.71 $\mu\textrm{g}$/㎥ (interquartile range) in PM$_{10}$ was associated with 1.3% (95% CI = 0.7∼1.9％) increase in the daily number of death. $O_3$ concentrations resulted in an increased risk of 1.3% for 23.86 ppb in all-aged mortality [RR = 1.013 (1.004-1.023)1. This effect was greater in children (less than 15 aged) and elderly (more than 65 aged). After ozone level exceeds 25 ppb, the dose-response relationship between mortality and ozone was almost linear. We concluded that Seoul had 1∼5％ increase in mortality in association with IQR (interquartile range) in air pollutants. Daily variations in air pollution within the range currently occurring in Seoul might have an adverse effect on daily mortality. These findings also support the hypothesis that air pollution, at levels below the current ambient air quality standards of Korea, is harmful to sensitive subjects, such as children or elderly.rly.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.8009-8013
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• 2015

Background: Orthotopic organ transplantation, a treatment option for irreversible organ dysfunction according to organ failure, severe damaged organ or malignancy in situ, was usually accompanied with massive blood loss thus transfusion was required. We aimed to evaluate the adverse impact of blood transfusion on solid organ transplantation. Materials and Methods: From January, 2009 to December, 2014, patients who received orthotopic organ transplantation at Far Eastern Memorial Hospital medical center were enrolled. Clinical data regarding anemia status and red blood cell (RBC) transfusion before, during and after operation, as well as patient outcomes were collected for further univariate analysis. Results: A total of 105 patients who underwent orthotopic transplantation, including liver, kidney and small intestine were registered. The mean hemoglobin (Hb) level upon admission and before operation were $11.6{\pm}1.8g/dL$ and $11.7{\pm}1.7g/dL$, respectively; and the nadir Hb level post operation and the final Hb level before discharge were $8.3{\pm}1.6g/dL$ and $10.2{\pm}1.6g/dL$, respectively. The median units (interquartile range) of RBC transfusion in pre-operative, peri-operative and post-operative periods were 0 (0-0), 2 (0-12), and 2 (0-6) units, respectively. Furthermore, the median (interquartile range) length of hospital stay (LHS) from admission to discharge and from operation to discharge were 28 (17-44) and 24 (16-37) days, respectively. Both peri-operative and post-operative RBC transfusion were associated with longer LHS from admission to discharge and from operation to discharge. Furthermore, it increased the risk of post-operative septicemia. While peri-operative RBC transfusion elevated the risk of acute graft rejection in patients who received orthotopic transplantation. Conclusions: Worse outcome could be anticipated in those who had received massive RBC transfusion in transplantation operation. Hence, peri-operative RBC transfusion should be avoided as much as possible.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4115-4119
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• 2013

Background: Previous reports have shown that human epidermal receptor (HER)-3 overexpression may be associated with poor prognosis in patients with breast cancer, but results have been conflicting. In this study, we sought to investigate the prognostic significance of HER-3 immunohistochemical expression in patients with metastatic breast cancer. Methods: We retrospectively analyzed HER-3 immunohistochemical expression profiles in 45 paraffin-embedded specimens from patients who had been treated between 1996 and 2006 in the Department of Oncology of the Uludag University School of Medicine, Bursa, Turkey. Membranous or cytoplasmic dominant expression patterns of HER-3 were analyzed using the Rajkumar score and a cytoplasmic 4-point scoring system, respectively. Progression-free survival (PFS) and overall survival (OS) served as the main outcome measures. Results: The median PFS in the study participants was 9 months (interquartile range: 4.5-13 months), whereas the median OS was 20 months (interquartile range: 7.5-28 months). Categorization of the patient population according to HER-3 positive immunohistochemical expression did not reveal any statistically significant difference in terms of both PFS (p=0.70) and OS (p=0.81). The results of multivariable Cox regression analysis indicated that tumor size was the only independent predictor of PFS, whereas estrogen and progesterone receptor status was independently associated with OS. Conclusions: HER-3 immunohistochemical expression did not correlate with outcomes in Turkish patients with metastatic breast cancer. Although our results suggest that HER-3 expression in cancer specimens is not of prognostic significance, further prospective studies are warranted to confirm these results.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10905-10909
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• 2015

Purpose: The aim of this study was to evaluate the diagnostic value of FNA-Tg for detecting lymph node metastases in patients with a history of differentiated thyroid cancer (DTC). Materials and Methods: A total of 58 patients with DTC diagnosis and evidence of single or multiple suspicious cervical lymph nodes were assessed. All underwent total or near-total thyroidectomy with (35 cases) or without (23 cases) radioiodine (RAI) ablation, followed by thyroid stimulating hormone (TSH) suppression therapy. A total of 68 lymph nodes were examined by ultrasound-guided fine needle aspiration (US-FNA) for both cytological examination and FNA-Tg measurement. Serum Tg and anti-thyroglobulin antibody (TgAb) levels were also measured. Diagnostic performance including sensitivity, specificity, accuracy, positive (PPV) and negative predictive value (NPV) of FNAC and FNA-Tg were calculated and compared. The Spearman's rank correlation coefficient was used to estimate the relationship between FNA-Tg and serum TgAb. Results: The FNA-Tg levels were significantly higher with DTC metastatic lymph nodes (median 927.7 ng/mL, interquartile range 602.9 ng/mL) than non-metastatic lymph nodes (median 0.1 ng/mL, interquartile range 0.4 ng/mL) (p<0.01). Considering 1.0 ng/mL as a threshold value for FNA-Tg, the sensitivity, specificity, accuracy, PPV and NPV of FNA-Tg were 95.7%, 95.5%, 95.6%, 97.8% and 91.3%, respectively. The sensitivity and accuracy of the combination of FNAC and FNA-Tg were significantly higher than that of FNAC alone (p<0.05). The diagnostic performance of FNA-Tg was not significantly different between cases with or without RAI ablation, and the serum TgAb levels did not interfere with FNA-Tg measurements. Conclusions: Measurement of FNA-Tg is useful. The combination of FNAC and FNA-Tg is more sensitive and accurate for detecting lymph node metastases in patients with a history of DTC than FNAC alone. Serum TgAbs appear to be irrelevant for measurement of FNA-Tg.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.524-537
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• 2017

Post-Environmental impact investigation(Post-EII) plays an important role in investigating and reducing the environmental impacts of construction operations in South Korea. To date, it has been estimated that the results for Post-EII showed the low reliability; however, understanding those reliability has rarely been studied. We investigated the effect on water qualities by construction operations of the quarry mine, training center, and golf club in South Korea. In addition, the results of water quality analysis in this study were compared and analyzed with those in Post-EII. Treated wastewater in a quarry mine showed high concentrations of biochemical oxygen demand(BOD), suspended solid(SS), total nitrogen(T-N), and total phosphorus(T-P). Compared with the water quality results between this study and Post-EII, the concentrations of BOD, SS, T-N, and T-P in the treated wastewater were higher than the interquartile range(IQR) as well as the range of the results from minimum to maximum in Post-EII(p<0.05). The concentrations of BOD, SS, T-N, and T-P in treated wastewater were high under constructions in a training center. The concentrations of BOD and SS exceeded the consultation standard for the treated wastewater. These concentrations showed the significant difference with the IQR and the range from minimum to maximum of the water quality results in Post-EII(p<0.05). Therefore, the management and monitoring for water quality should be conducted in the treated wastewater by of construction operations. In addition, the alternative to enhance the reliability for the water quality results should be sought in Post-EII.

• Journal of the Korean School Mathematics Society
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• v.22 no.4
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• pp.501-520
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• 2019

This study compared and analyzed Korean, American, Singaporean, and Japanese middle school mathematics curriculum standards and the learning contents in statistics. Through a comparative analysis of the curriculums of these four countries, I found several overall features and differences between the curriculums. First, all four countries emphasized statistical education in a real-life context. Second, all four countries emphasized the use of technological tools. Third, there is a middle school grade in which only Korea does not deal with statistical domains. Fourth, the statistical areas of the United States, Singapore, and Japan focused on identifying trends or variability in data distribution. Fifth, I have found some contents that only Korea does not deal with. Based on this, the following recommendations were developed for the development of the next curriculum and new textbooks in Korea. First, the statistics curriculum should be changed from one that focuses on understanding statistical concepts to one that focuses on statistical activity that utilizes these concepts. Second, in terms of middle school statistical curriculum contents, the addition of interquartile range (IQR) and box plots as learning contents should be considered. IQR and box plots are simple and practical techniques for the comparison of multiple sets of data that can be easily learned and drawn by middle school level students and applied to real-life-related statistical data to expand statistical literacy. Through this study, it is suggested that IQR and box plots need to be included in the statistical curriculum of middle schools in Korea.