• 대기
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• 제29권5호
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• pp.585-597
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• 2019

This study evaluates the performance of Weather Research and Forecasting (WRF) model in simulating temperature over the COordinated Regional climate Downscaling EXperiment-East Asia (CORDEX-EA) Phase 2 domain for the reference period (1981~2005), and assesses the changes in temperature and its extremes in the mid-21st century (2026~2050) under global warming based on Representative Concentration Pathway (RCP) scenarios. MPI-ESM-LR forced by two RCP scenarios (RCP2.6 and RCP8.5) is used as initial and lateral boundary conditions. Overall, WRF can capture the observed features of temperature distribution reflecting local topographic characteristic, despite some disagreement between the observed and simulated patterns. Basically, WRF shows a systematic cold bias in daily mean, minimum and maximum temperature over the entire domain. According to the future projections, summer and winter mean temperatures over East Asia will significantly increase in the mid-21st century. The mean temperature rise is expected to be greater in winter than in summer. In accordance with these results, summer (winter) is projected to begin earlier (later) in the future compared to the historical period. Furthermore, a rise in extreme temperatures shows a tendency to be greater in the future. The averages of daily minimum and maximum temperatures above 90 percentiles are likely to be intensified in the high-latitude, while hot days and hot nights tend to be more frequent in the low-latitude in the mid-21st century. Especially, East Asia would be suffered from strong increases in nocturnal temperature under future global warming.

• 대한지리학회지
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• 제44권3호
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• pp.355-371
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• 2009

본 연구는 국내 광산업 기술지식 창출의 공간구조를 살펴보는데 목적을 둔다. 지식창출의 대리지표로서 특허데이터를 활용하였으며, 키워드를 이용하여 1996${\sim}$2007년 사이에 출원된 광산업 등록특허를 대상으로 했다. 미국특허상표청에 등록된 광산업 특허는 한국이 대만과 더불어 광산업 분야의 후발주자로서 급속히 성장하고 있음을 보여주었다. 한국특허청에 등록된 광산업 특허는 단독특허와 공동특허로 구분하여 살펴보았다. 단독특허의 경우, 광산업 기술지식이 서울, 수원, 대전에 상당히 편중되어 창출되고 있지만 편중 정도는 점차 완화되고 있음을 보여주었다. 공동특허의 경우도 상기된 지역들이 대체로 중심적인 위치를 차지하지만, 지역 간 군집과 연결 양상은 시기별로 상이했다. 공동특허에 참여하는 주체가 다양해진데 기인하며 정보통신 인프라 개선, 광산업 육성, 산학 협력 촉진과 같은 정책적 영향이 주요했던 것으로 보인다.

• 한국농공학회논문집
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• 제62권6호
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• pp.1-9
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• 2020

Reservoir storage and water level information is essential for accurate drought monitoring and prediction. In particular, the agricultural drought has increased the risk of agricultural water shortages due to regional bias in reservoirs and water supply facilities, which are major water supply facilities for agricultural water. Therefore, it is important to evaluate the available water capacity of the reservoir, and it is necessary to determine the water surface area and water capacity. Remote sensing provides images of temporal water storage and level variations, and a combination of both measurement techniques can indicate a change in water volume. In areas of ungauged water volume, satellite remote sensing image acts as a powerful tool to measure changes in surface water level. The purpose of this study is to estimate of reservoir storage and level variations using satellite remote sensing image combined with hydrological statistical data and the Normalized Difference Water Index (NDWI). Water surface areas were estimated using the Sentinel-2 satellite images in Seosan, Chungcheongnam-do from 2016 to 2018. The remote sensing-based reservoir storage estimation algorithm from this study is general and transferable to applications for lakes and reservoirs. The data set can be used for improving the representation of water resources management for incorporating lakes into weather forecasting models and climate models, and hydrologic processes.

• 대한두경부종양학회지
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• 제24권1호
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• pp.64-68
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• 2008

Purpose：The chronic use of immunosuppressive therapy in transplant recipients can increase the long-term risk of carcinoma. The aim of this study was to determine the incidence, biological behaviors, and treatment outcomes in PTC(papillary thyroid carcinoma) in renal allograft recipients. Material and Methods：The present study examined the incidence and biological behavior of PTCs in RA recipients. A total of 1,739 RA patients treated between January 1986 and December 1999 were followed-up for a median 137(84-238) months. During the follow-up period, 129(7.4%) recipients were identified as having posttransplant malignancies. Of those, 12(0.7%) had PTCs, and these comprised six male and six female patients with a median age of 41(23-57) years. Results：Nine cases(incidentalomas) were diagnosed based on ultrasonography(US) screening. Eight of those nine were TNM stage I, and two of the three clinical carcinomas were TNM stage IVa. During a median follow-up of 94(18-159) months, two(16.7%) PTC patients developed loco-regional recurrence, but no patients showed distant metastasis. Posttransplant PTC showed no gender bias, and was often associated with aggressive lymphatic metastasis. However, most incidentalomas showed a favorable treatment outcome. Conclusion：In conclusion, routine surveillance of the thyroid gland using US screening is recommended to ensure early detection, treatment and favorable prognosis in RA patients with PTC.

• 한국태양에너지학회 논문집
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• 제30권2호
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• pp.72-80
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• 2010

The main thrust of this paper is to investigate a practical way of generating the monthly averaged daily horizontal solar radiation in Korea. For estimating the horizontal solar radiation, the clearness index($K_T$) and the clearness number($C_N$) which are required for the use of Liu and Jordan's model and ASHRAE Clear Sky model were derived based on the measured weather data. Third-order polynomials returning $K_T$ and��$C_N$ for a given location were derived as a function of cloud amount, month, date, latitude and longitude. The predicted monthly averaged daily horizontal solar radiation values were compared with those acquired from the established design weather data. The MBE(Mean Bias Error) and RMSE (Root Mean Squares for Error) between the predicted values and the measured data were near zero. It means that the suggested third-order polynomials for $K_T$ and $C_N$ have good applicability to Liu and Jordan's model and ASHRAE Clear Sky model.

• 한국지구과학회지
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• 제40권4호
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• pp.406-413
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• 2019

Red-Green-Blue (RGB) imagery techniques are useful for both forecasters and public users because they are intuitively understood, have advantageous visualization, and do not lose observational information. This study presents a novel RGB convective cloud product and its application to tropical cyclone analysis using Communication, Oceanography, and Meteorology (COMS) satellite observations. The RGB convective cloud product was developed using the brightness temperature differences between WV ($6.75{\mu}m$) and IR1 ($10.8{\mu}m$), and IR2 ($12.0{\mu}m$) and IR1 ($10.8{\mu}m$) as well as the brightness temperature in the IR1 bands of the COMS, with the threshold values estimated from the Korea Meteorological Administration (KMA) radar observations and the EUMETSAT RGB recipe. To verify the accuracy of the convective cloud RGB product, the product was applied to the center positions analysis of two typhoons in 2013. Thus, the convective cloud RGB product threshold values were estimated for WV-IR1 (-20 K to 15 K), IR1 (210 K to 300 K), and IR1-IR2 (-4 K to 2 K). The product application in typhoon analysis shows relatively low bias and root mean square errors (RMSE)s of 23 and 28 km for DANAS in 2013, and 17 and 22 km for FRANCISCO in 2013, as compared to the best tracks data from the Regional Specialized Meteorological Center (RSMC) in Tokyo. Consequently, our proposed RGB convective cloud product has the advantages of high accuracy and excellent visualization for a variety of meteorological applications.

• 대한물리의학회지
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• 제14권1호
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• pp.63-73
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• 2019

PURPOSE: This study examined the effects of cardiopulmonary physiotherapy on the cardiopulmonary function, metabolism, inflammatory markers, and quality of life in patients with coronary artery disease who underwent percutaneous coronary intervention (PCI). METHODS: Electronic bibliographic databases of a regional information sharing system (RISS) and PubMed were searched to identify studies with randomized and non-randomized controlled trials. As the final outcome, 320 publications were identified and 18 studies met the inclusion and exclusion criteria. All studies were assessed for the quality of study using Cochrane's risk of bias. RESULTS: Sixteen studies met the inclusion criteria, in which meta-analysis had been conducted to examine the effectiveness of cardiopulmonary physiotherapy on the cardiopulmonary function, metabolism, inflammatory markers, and quality of life in patients undergoing PCI. Meta-analysis based on a random effect model showed that the cardiopulmonary physiotherapy was beneficial in improving the cardiopulmonary function, metabolism, inflammatory markers, and quality of life. In particular, there was a significant effect on the peak oxygen uptake (effect size 5.30%; 95% confidence interval 3.62~6.97). Cardiopulmonary physiotherapy for a during period of 6 weeks or more was effective in significantly improving the cardiopulmonary function and metabolism function in a subgroup analysis, but cardiopulmonary physiotherapy for less than 6 weeks was not effective. CONCLUSION: Cardiopulmonary physiotherapy has positive effects on the cardiopulmonary function, metabolism, inflammatory markers, and quality of life in patients undergoing PCI.

• Imaging Science in Dentistry
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• 제52권3호
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• pp.239-244
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• 2022

Purpose: Despite the proliferation of numerous morphometric and anthropometric methods for sex identification based on linear, angular, and regional measurements of various parts of the body, these methods are subject to error due to the observer's knowledge and expertise. This study aimed to explore the possibility of automated sex determination using convolutional neural networks(CNNs) based on lateral cephalometric radiographs. Materials and Methods: Lateral cephalometric radiographs of 1,476 Iranian subjects (794 women and 682 men) from 18 to 49 years of age were included. Lateral cephalometric radiographs were considered as a network input and output layer including 2 classes(male and female). Eighty percent of the data was used as a training set and the rest as a test set. Hyperparameter tuning of each network was done after preprocessing and data augmentation steps. The predictive performance of different architectures (DenseNet, ResNet, and VGG) was evaluated based on their accuracy in test sets. Results: The CNN based on the DenseNet121 architecture, with an overall accuracy of 90%, had the best predictive power in sex determination. The prediction accuracy of this model was almost equal for men and women. Furthermore, with all architectures, the use of transfer learning improved predictive performance. Conclusion: The results confirmed that a CNN could predict a person's sex with high accuracy. This prediction was independent of human bias because feature extraction was done automatically. However, for more accurate sex determination on a wider scale, further studies with larger sample sizes are desirable.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.174-174
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• 2023

The impact of global warming on the south Asian summer monsoon is of critical importance for the large population of this region. This study aims to investigate the future changes of the precipitation extremes during pre-monsoon and monsoon, across this region in a more organized regional structure. The study area is divided into six major divisions based on the Köppen-Geiger's climate structure and 10 sub-divisions considering the geographical locations. The future changes of extreme precipitation indices are analyzed for each zone separately using five indices from ETCCDI (Expert Team on Climate Change Detection and Indices); R10mm, Rx1day, Rx5day, R95pTOT and PRCPTOT. 10 global climate model (GCM) outputs from the latest CMIP6 under four combinations of SSP-RCP scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) are used. The GCMs are bias corrected using nonparametric quantile transformation based on the smoothing spline method. The future period is divided into near future (2031-2065) and far future (2066-2100) and then the changes are compared based on the historical period (1980-2014). The analysis is carried out separately for pre-monsoon (March, April, May) and monsoon (June, July, August, September). The methodology used to compare the changes is probability distribution functions (PDF). Kernel density estimation is used to plot the PDFs. For this study we did not use a multi-model ensemble output and the changes in each extreme precipitation index are analyzed GCM wise. From the results it can be observed that the performance of the GCMs vary depending on the sub-zone as well as on the precipitation index. Final conclusions are made by removing the poor performing GCMs and by analyzing the overall changes in the PDFs of the remaining GCMs.

• Journal of Korean Neurosurgical Society
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• 제65권1호
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• pp.130-137
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• 2022

Objective : COVID-19 has spread worldwide since the first case was reported in Wuhan, China, in December 2019. Our institution is a regional trauma and emergency center in the northern Gyeonggi Province. The changing trend of patient care in the emergency room of this hospital likely reflects the overall trend of patients in the area. In the present study, whether changes in the surrounding social environment following the outbreak of COVID-19 changed the incidence of neurosurgical emergency patients and whether differences in practice existed were investigated. Methods : The overall trend was analyzed from January 2020 which is before the outbreak of COVID-19 to September 2020. To remove bias due to seasonal variation, the previous 2 year's records during the same period were reviewed and compared. Confirmed COVID-19 patients in the northern Gyeonggi Province were identified using data released by the government. And patients who came to the emergency department with head trauma and stroke were identified. Results : Based on the present study results, the total number of neurosurgery emergency patients decreased over the study period. In the trauma patient group, the number of patients not involved in traffic accidents significantly decreased compared with patients involved in traffic accidents. Among the stroke cases, the rate of ischemic stroke was lower than hemorrhagic stroke, although a statistically significant difference was not observed. Meanwhile, an increase in the risk of mortality associated with trauma or stroke cases was not observed during the COVID-19 outbreak compared with the same time period in the previous year. Conclusion : Due to the occurrence of COVID-19, non-essential activities have decreased and trauma cases not associated with traffic accidents appeared to decrease. Due to the decrease in overall activity, the number of stroke patients has also decreased. This trend is expected to continue even in the post-COVID-19 era, and accordingly, the results from the present study are relevant especially if the current situation continues.