• 한국학교수학회논문집
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• 제22권4호
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• pp.501-520
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• 2019

본 연구의 목적은 한국, 미국, 싱가포르, 일본의 중학교 수학과 교육과정의 통계영역의 성취기준과 학습 요소를 중심으로 비교·분석하여 우리나라의 중학교 통계영역의 교육과정의 개선 방향에 대한 시사점을 얻기 위함이다. 교육과정 비교·분석 결과, 전반적인 성취기준과 학습 요소에 대한 특징과 차이점을 발견하였다. 첫째, 한국, 미국, 싱가포르, 일본 네 나라 모두 실생활 맥락에서의 통계교육을 강조하였다. 둘째, 네 나라 모두 공학적 도구의 활용을 강조하였다. 셋째, 우리나라만 통계영역을 다루지 않는 학년이 있다. 넷째, 미국, 싱가포르, 일본의 통계영역은 자료 분포의 경향을 파악하는데 중점을 두었다. 다섯째, 미국, 싱가포르, 일본에서는 다루지만 우리나라에서는 다루지 않는 학습 요소를 몇 가지 찾을 수 있었다. 이를 바탕으로 우리나라의 차기 교육과정 개발과 새로운 교과서 개발을 위한 시사점을 도출하였다. 첫째, 통계적 개념의 이해 위주에서 이를 활용한 통계적 활동 중심의 교육과정이 되어야 한다. 둘째, 중학교 통계영역 교육과정의 학습 요소 개선 측면에서, 사분위범위와 상자 그림을 학습 요소로 추가하는 것을 고려할 필요가 있다. 사분위범위와 상자 그림은 자료 분석 영역에서 복수의 집단 간의 비교를 위한 간단하고 실용적인 기법으로, 중학생 수준의 학생들이 간단히 배워서 쉽게 그릴 수 있고, 실생활 관련 통계적 자료에 적용하면서 통계적 소양을 확충할 수 있다. 본 연구를 통해 사분위범위와 상자 그림이 우리나라 중학교 통계영역 교육과정에도 새롭게 추가 선정될 필요가 있음을 제안한다.

• 대한임상독성학회지
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• 제17권2호
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• pp.118-125
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• 2019

Purpose: Non-benzodiazepine hypnotic drugs (including zolpidem) are associated with an increased risk of suicide and suicidal ideation. Considering the wide usage of zolpidem, this drug should be considered a possible etiology for stupor or coma in any patient exposed to this drug. However, there are no reports on zolpidem blood levels in emergency department patients in Korea. We therefore reviewed the analyzed data of a toxicology laboratory at one university affiliated hospital. Methods: The sex, age, chief symptoms, suspiciousness of poisoning, and presumption of poison were analyzed from January 2018 to June 2019. The detection frequency and level of zolpidem in the patient blood were compared to the mental changes presented, which is the main consequence of zolpidem. Results: A total of 229 toxicological analyses, requested to a toxicological laboratory at one university affiliated hospital, were reviewed. Among 229 patients, the mean age was 54.3±20.7 years old with 113 women and 116 men. 8.7% of patients have psychiatric illness and 39.7% were poisoned intentionally. The chief symptoms detected were: mental change 55.0%, gastrointestinal 14.4%, cardiovascular 10.5%, focal neurological 7.4%, respiratory 3.5%, none 8.7%, and unknown 0.4%. A request for detailed reports revealed that causative poisons were specified only in 20.1% cases. Zolpidem was detected in 22.3% cases (51/229), with median blood level 1.26 mg/L (interquartile 0.1, 5.06 mg/L) and urine 0.90 mg/L (interquartile 0.11, 5.6 mg/L). Furthermore, zolpidem was more frequently detected in toxicology analysis of patients where mental change was the primary symptom, as compared to other symptoms (32.5% vs. 9.7%, p<0.01). Conclusion: This study reported the blood level of zolpidem in suspected poisoning patients admitted to the emergency department.

• 한국전산구조공학회논문집
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• 제36권6호
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• pp.407-414
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• 2023

본 논문에서는 다양한 분야에 적용할 수 있는 자동화 동시 인상 시스템을 3D 콘크리트 프린팅에 적용하여 동시 인상이 가능한 3D 콘크리트 프린팅 시스템으로 개발하였다. 개발된 시스템은 3D 콘크리트 프린팅 작업 중 측정되는 인상량을 피어슨 상관계수를 통해 분석하고, 유압시스템을 사분위수 기법으로 실시간 모니터링하여 안전하고 정밀한 인상이 가능하다. 이를 활용하면 3D 콘크리트 프린팅 구조물의 출력 품질을 확보함과 동시에 3D 콘크리트 프린팅의 규모보다 큰 구조물을 출력할 수 있다. 시스템의 성능을 평가하기 위해 기존의 3D 콘크리트 프린팅과 동시 인상이 가능한 3D 콘크리트 프린팅을 각각 이용하여 시편을 출력하였다. 출력된 시편은 3D 스캐너를 활용하여 측정하였다. 스캔한 시편의 층별 직경과 시편의 교차각을 측정하였으며, 분석을 통해 동시 인상이 가능한 3D 콘크리트 프린팅의 성능을 검증하였다.

• Korean Journal of Radiology
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• 제22권6호
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• pp.922-930
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• 2021

Objective: It is uncertain why a b-value range of 1500-2000 s/mm² is optimal. This study was aimed at qualitatively and quantitatively analyzing the optimal b-value range of synthetic diffusion-weighted imaging (sDWI) for evaluating prostatic index lesions. Materials and Methods: This retrospective study included 92 patients who underwent DWI and targeted biopsy for magnetic resonance imaging (MRI)-suggested index lesions. We generated sDWI at a b-value range of 1000-3000 s/mm² using dedicated software and true DWI data at b-values of 0, 100, and 1000 s/mm². We hypothesized that lesion conspicuity would be best when the background (i.e., MRI-suggested benign prostatic [bP] and periprostatic [pP] regions) signal intensity (SI) is suppressed and becomes homogeneous. To prove this hypothesis, we performed both qualitative and quantitative analyses. For qualitative analysis, two independent readers analyzed the b-value showing the best visual conspicuity of an MRI-suggested index lesion. For quantitative analysis, the readers assessed the b-value showing the same bP and pP region SI. The 95% confidence interval (CI) or interquartile range of qualitatively and quantitatively selected optimal b-values was assessed, and the mean difference between qualitatively and quantitatively selected b-values was investigated. Results: The 95% CIs of optimal b-values from qualitative and quantitative analyses were 1761-1805 s/mm² and 1640-1771 s/mm² (median, 1790 s/mm² vs. 1705 s/mm²; p = 0.003) for reader 1, and 1835-1895 s/mm² and 1705-1841 s/mm² (median, 1872 s/mm² vs. 1763 s/mm²; p = 0.022) for reader 2, respectively. Interquartile ranges of qualitatively and quantitatively selected optimal b-values were 1735-1873 s/mm² and 1573-1867 s/mm² for reader 1, and 1775-1945 s/mm² and 1591-1955 s/mm² for reader 2, respectively. Bland-Altman plots consistently demonstrated a mean difference of less than 100 s/mm² between qualitatively and quantitatively selected optimal b-values. Conclusion: b-value range showing a homogeneous background signal may be optimal for evaluating prostatic index lesions on sDWI. Our qualitative and quantitative data consistently recommend b-values of 1500-2000 s/mm².

• Korean Journal of Radiology
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• 제22권8호
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• pp.1253-1265
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• 2021

Objective: To investigate the prognostic value of preoperative cardiac magnetic resonance imaging (MRI) for long-term major adverse cardiac and cerebrovascular events (MACCEs) in patients undergoing tricuspid valve (TV) surgery for functional tricuspid regurgitation (TR). Materials and Methods: The preoperative cardiac MR images, New York Heart Association functional class, comorbidities, and clinical events of 78 patients (median [interquartile range], 59 [51-66.3] years, 28.2% male) who underwent TV surgery for functional TR were comprehensively reviewed. Cox proportional hazards analyses were performed to assess the associations of clinical and imaging parameters with MACCEs and all-cause mortality. Results: For the median follow-up duration of 5.4 years (interquartile range, 1.2-6.6), MACCEs and all-cause mortality were 51.3% and 23.1%, respectively. The right ventricular (RV) end-systolic volume index (ESVI) and the systolic RV mass index (RVMI) were higher in patients with MACCEs than those without them (77 vs. 68 mL/m², p = 0.048; 23.5 vs. 18.0%, p = 0.011, respectively). A high RV ESVI was associated with all-cause mortality (hazard ratio [HR] per value of 10 higher ESVI = 1.10, p = 0.03). A high RVMI was also associated with all-cause mortality (HR per increase of 5 mL/m² RVMI = 1.75, p < 0.001). After adjusting for age and sex, only RVMI remained a significant predictor of MACCEs and all-cause mortality (p < 0.05 for both). After adjusting for multiple clinical variables, RVMI remained significantly associated with all-cause mortality (p = 0.005). Conclusion: RVMI measured on preoperative cardiac MRI was an independent predictor of long-term outcomes in patients who underwent TV surgery for functional TR.

• Korean Journal of Radiology
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• 제23권1호
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• pp.68-76
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• 2022

Objective: Percutaneous portal vein (PV) stent placement can be an effective treatment for symptoms associated with portal hypertension. This study aimed to evaluate the effect of PV stenting on the overall survival (OS) in patients with malignant PV stenosis. Materials and Methods: Two groups of patients with malignant PV stenosis were compared in this retrospective study involving two institutions. A total of 197 patients who underwent PV stenting between November 2016 and August 2019 were established as the stent group, whereas 29 patients with PV stenosis who were treated conservatively between July 2013 and October 2016 constituted the no-stent group. OS was compared between the two groups before and after propensity score matching (PSM). Risk factors associated with OS were evaluated using the Cox proportional hazards model. Procedure-associated adverse events were also evaluated. Results: The stent group finally included 100 patients (median age, 65 [interquartile range, 58-71] years; 64 male). The no-stent group included 22 patients (69 [61-75] years, 13 male). Stent placement was successful in 95% of attempted cases, and the 1- and 2-year stent occlusion-free survival rate was 56% (95% confidence interval, 45%-69%) and 44% (32%-60%), respectively. The median stent occlusion-free survival time was 176 (interquartile range, 70-440) days. OS was significantly longer in the stent group than in the no-stent group (median 294 vs. 87 days, p < 0.001 before PSM, p = 0.011 after PSM). The 1- and 3-year OS rates before PSM were 40% and 11%, respectively, in the stent group. The 1-year OS rate after PSM was 32% and 5% in the stent and no-stent groups, respectively. Anemia requiring transfusion (n = 2) and acute thrombosis necessitating re-stenting (n = 1) occurred in three patients in the stent group within 1 week. Conclusion: Percutaneous placement of a PV stent may be effective in improving OS in patients with malignant PV stenosis.

• The Korean journal of internal medicine
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• 제39권4호
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• pp.603-611
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• 2024

Background/Aims: There is limited knowledge regarding the management of duodenal subepithelial lesions (SELs) owing to a lack of understanding of their natural course. This study aimed to assess the natural course of asymptomatic duodenal SELs and provide management recommendations. Methods: Patients diagnosed with duodenal SELs and followed up for a minimum of 6 months were retrospectively investigated. Results: Among the 443,533 patients who underwent esophagogastroduodenoscopy between 2008 and 2020, duodenal SELs were identified in 0.39% (1,713 patients). Among them, 396 duodenal SELs were monitored for a median period of 72.5 months (interquartile range, 37.7-111.3 mo). Of them, 16 SELs (4.0%) showed substantial changes in size or morphology at a median follow-up of 35.1 months (interquartile range, 21.7-51.4 mo). Of these SELs with substantial changes, tissues of two SELs were acquired using endoscopic ultrasound-guided fine needle aspiration biopsy: one was a lipoma and the other was non-diagnostic. Three SELs were surgically or endoscopically removed; two were diagnosed as gastrointestinal stromal tumors, and one was a lipoma. An initial size of 20 mm or larger was associated with substantial changes during follow-up (p = 0.016). Conclusions: While the majority of duodenal SELs may not exhibit substantial interval changes, regular follow-up with endoscopy may be necessary for cases with an initial size of 20 mm or larger, considering a possibility of malignancy.

• 한국환경보건학회지
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• 제34권5호
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• pp.361-368
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• 2008

Objective to assess whether exposure to air pollutants is associated with postneonatal infant death, using a timeseries methodology, between 1999 and 2003 in Seoul, Korea.. Methods We investigated the short-term effects of air pollution for 548,725 live births during the study period. The daily count of postneonatal infant deaths from all causes and from SIDS (sudden infant death syndrome) by birth order was analyzed by a Generalized Additive Poisson model, with controlling for the effects of seasonal trends, air temperature, relative humidity, barometric pressure, and day of the week as covariates. Results During the study period, we observed 699 deaths from all causes and 47 deaths from SIDS. We did not find any significant associations between daily mortality and ambient levels of air pollutants except for CO and $NO_2$. The estimated relative risk of postneonatal infant death from all causes was 1.17 (95% CI=1.04-1.32) and 1.16 (95% CI=1.03-1.29) by IQR (interquartile range) for CO and $NO_2$ respectively. Also, we observed no clear trend of the mortality effects of air pollution by birth orders. Conclusion In conclusion, our findings suggest that air pollution, in general, influenced adversely postneonatal infant death from all-cause and SIDS although it was not statistically significant. This study may support that the rationale.

• 한국의류산업학회지
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• 제7권6호
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• pp.601-608
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• 2005

This research investigated the present state of the dress forms used by clothing manufacturers and proposed procedure to bring out the standardized body type and figure for women in twenties. The result of questionnaire showed chief pattern maker's thoughts that dress form should be differently made for each age group and should be more reflected the standard body than the idea body. The standardized body type was made from the standardized posture and size which were analyzed from the interquartile range(IQR) of 314 subjects. The standardized size could be verified as for the balanced body shape of twenties through making the standard dress form. The standardized form(S form) was compared with three kinds of forms(A, K and P) for investigating the suitability of forms. K form was very similar to S form, Educational P form and manufacturer's A form had quite big differences from S form at the important areas for making clothing. The side shapes of A, K and P forms showed differences at back bending, neck angle and hip shape from S form. A form was comparatively smooth and flat. This results could be used as the practical standard to improve the suitability of size and shape in the dress forms of manufacturers and educators.

• 한국수자원학회논문집
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• 제43권11호
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• pp.933-944
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• 2010

본 논문에서는 확률강우량에 대한 공간분포 추정에 있어서 공간변동성에 따른 불확실성을 평가하기 위하여 지구통계 학적 추계모의기법인 CEM과 SGS 기법을 비교하였다. CEM과 SGS를 이용한 추계모의에 있어서 공간상관구조의 재생성, 확률강우량에 대한 불확실성 평가측도로서 실현치에 대한 통계치(표준편차, 변동계수, 사분위수 범위 및 범위)의 공간분포, 유역평균강우량의 불확실성 분포의 경우 두 기법이 대체로 비슷한 결과를 보이는 것으로 분석되었다. 그러나 모의 효율성 측면에서는 CEM이 SGS에 비해 우수한 결과를 나타내는 것으로 분석되었다.