• Journal of Climate Change Research
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• v.9 no.1
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• pp.31-45
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• 2018

This study implemented the prediction of drought properties (number of drought events, intensity, duration) using the user-oriented systematical procedures of downscaling climate change scenarios based the multiple global climate models (GCMs), AIMS (APCC Integrated Modeling Solution) program. The drought properties were defined and estimated with Effective Drought Index (EDI). The optimal 10 models among 29 GCMs were selected, by the estimation of the spatial and temporal reproducibility about the five climate change indices related with precipitation. In addition, Simple Quantile Mapping (SQM) as the downscaling technique is much better in describing the observed precipitation events than Spatial Disaggregation Quantile Delta Mapping (SDQDM). Even though the procedure was systematically applied, there are still limitations in describing the observed spatial precipitation properties well due to the offset of spatial variability in multi-model ensemble (MME) analysis. As a result, the farther into the future, the duration and the number of drought generation will be decreased, while the intensity of drought will be increased. Regionally, the drought at the central regions of the Korean Peninsula is expected to be mitigated, while that at the southern regions are expected to be severe.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1091-1102
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• 2009

This study developed an integrated approach to climate change and urbanization impact assessment by linking models of SDSM (statistical downscaling model), HSPF (hydrological simulation program?Fortran) and ICM (impervious cover model). A case study of the Anyangcheon watershed illustrated how the proposed framework can be used to analyze the impacts of climate change and urbanization in terms of flood control, water security and water quality. The evaluation criteria were the variations of flow and pollutant concentration duration curves. In this study, nine scenarios including three climate (present condition, A1B and A2) and three urbanization scenarios were analyzed using HSPF model. As a result, climate change is a large influence on the flowrate and the urbanization affects the pollutant concentration. Therefore, the impacts of both climate change and urbanization must be included into the watershed management and water resources planning for sustainable development.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.510-515
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• 2011

Urban renewal projects, in the form of mega-projects, are being actively implemented both nationally and internationally to revitalize inactive cities. These programs, however, are difficult to manage efficiently due to their need for a large budget over a long period of time and due to conflicts with stockholders. Moreover, existing cost and duration management systems are structured with emphasis on the design and construction stage of unit projects, thus limiting their application to long-term mega-projects that are integrated with various facilities. To solve these problems, this study developed a web-based system that can collectively manage the cost and duration of mega-projects at a program level. The unit modules included in the system--CBS organization, construction cost and duration prediction, and total cost and duration prediction--can support decision-making at the early stage of the program. Furthermore, the modules, which include contract management, execution management, change management, and program progress management, support the program operations for its successful accomplishment. The web-based cost and duration management system developed in this study is expected to be used as a valuable tool that supports the successful accomplishment of mega-projects through their efficient management throughout their life cycle.

• The Journal of Korean Obstetrics and Gynecology
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• v.26 no.3
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• pp.59-72
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• 2013

Objectives: The aim of this study was to assess the duration of lochia in women hospitalized at Korean medical postpartum care center and to identify factors that influence duration of lochia. Methods: On the obstetric variables of 315 cases, the duration of lochia was analyzed. In the postpartum care center, the obstetric variables were asked of 315 cases of women, and who examined a body composition. After discharge, women were surveyed for the duration of lochia by telephone. Results: The median duration of lochia was 30 days and the range was 18~53 days. Maternal age, parity and mode of delivery were associated with its duration. So, its duration was longer on women over the age of 35, multipara and women had a Cesarean section. Its duration was correlated with gestational age and BMI before pregnancy, but not neonatal gender, birth weight, maternal BMI change during pregnancy, maternal body weight gain, BMI before delivery. Conclusions: It was 30 days that the median duration of lochia of women who had been got Korean medical postpartum care management, and which was slightly different from previous studies. And it was influenced by maternal age, parity, mood of delivery, gestational age and BMI before pregnancy. In future more studies or surveys for the duration of lochia of women with no treatment, lochial pattern and so on should be done.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.195-204
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• 1987

The purpose of this study was to investigate the effect of occlusal splints on the masseteric silent period and the changes of the masseteric silent period after experimental bruxism with occlusal splints. In nine subjects, anterior occlusal splints were fabricated. The jaw-jerk reflex was induced by tapping over mandibular symphysis area with solenoid driven hammer and electromyogram of left masseter muscle was recorded. In the recorded electromyogram of left masseter muscle the silent period duration was measured. This procedure was done before insertion of anterior occlusal splints, after insertion of anterior occlusal splints, after 30 min experimental bruxism with anterior occlusal splints, and 3hr after removal of anterior occlusal splints. The result were as follows; 1. The mean silent period duration was increased after insertion of occlusal splints compared with the mean silent period duration before insertion of occlusal splints. 2. There was no change of the mean silent period duration after 30 min experimental bruxism with occlusal splints compared with the mean silent period duration after insertion of occlusal splints. 3. 3hr after the removal of occlusal splints, the mean silent period duration showed no difference from the mean silent period duration before insertion of occlusal splints.

• Journal of Chest Surgery
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• v.22 no.2
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• pp.256-264
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• 1989

Modified Blalock-Taussig operation remains the standard technique of systemic-to-pulmonary artery shunt in patients of congenital heart disease with decreased pulmonary blood flow. We reviewed the 41 patients who had been performed modified Blalock-Taussig operation from March 1985 to Feb. 1988, and angiographically measured pulmonary artery size before and after shunt, and calculated pulmonary artery index [PAI] and ratio of left and right pulmonary artery to descending aorta[[LPA+RPA]/dAo]. The mean duration of palliation after shunt operation was 624 days and mean age of the patient at shunt operation was 3.59 years. Mean PAI increased significantly from 131.15*67.11 mm2/M2 preoperatively to 232.70*84.46 mm2/M2 postoperatively. Mean ratio of right and left pulmonary artery to descending aorta also increased significantly from 1.48*0.40 preoperatively to 1.92*0.50 postoperatively. All patients manifested clinical improvement; there was mean decrease in hematocrit of 8.95%, mean increase in arterial oxygen saturation of 11.08%. Pulmonary arterial growth was not influenced by age at operation, initial pulmonary artery size, or graft size, but significantly influenced by antegrade flow. The patients who have some antegrade flow were in more increase of PAI. There were no linear correlation between change of PAI, change of [[LPA+RPA]/dAo], SaO2, and duration. But, according to Scatterplot between change of PAI and duration, some complex correlation was suggested and mean PAI was decreased after 2-year palliation. We concluded that modified Blalock-Taussig operation is excellent palliative surgery for pulmonary artery growth especially on the patient who have some antegrade flow, and the proper duration of palliation was about 2 years.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.59-70
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• 2020

The purpose of this study is to construct the ACD model for the block trading volume duration. The ACD model based on the block trading volume duration is referred to as Volume ACD (VACD) in this study. By integrating with GARCH-type models, the VACD based GARCH type models, which include VACD-GARCH, VACD-IGARCH and VACD-FIGARCH models, are set up. This study selects Chunghwa Telecom (CHT) Inc., offering the America Depository Receipt (ADR) in NYSE, to investigate the block trading volume duration in Taiwanese equity market. The empirical results indicate that the long memory in volume duration series increases dependence at level of volatility clustering by VACD (2,1)-FIGARCH (3,d,1) model. Moreover, the VACD (2,1)-IGARCH (1,1) exhibits relatively better performance of prediction on capturing block trading volume duration. This volatility model is more appropriate in this study to portray the change of the CHT Inc. prices and provides more information about the volatility process for investment strategy, which can be a reference indicator of financial asset pricing, hedging strategy and risk management.

• Clinical and Experimental Pediatrics
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• v.61 no.11
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• pp.362-365
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• 2018

Purpose: This study aimed to analyze changes in QRS duration and cardiothoracic ratio (CTR) following pulmonary valve replacement (PVR) in patients with tetralogy of Fallot (TOF). Methods: Children and adolescents who had previously undergone total repair for TOF (n=67; median age, 16 years) who required elective PVR for pulmonary regurgitation and/or right ventricular out tract obstruction were included in this study. The QRS duration and CTR were measured pre- and postoperatively and postoperative changes were evaluated. Results: Following PVR, the CTR significantly decreased (pre-PVR $57.2%{\pm}6.2%$, post-PVR $53.8%{\pm}5.5%$, P=0.002). The postoperative QRS duration showed a tendency to decrease (pre-PVR $162.7{\pm}26.4$ msec, post-PVR $156.4{\pm}24.4$ msec, P=0.124). QRS duration was greater than 180 msec in 6 patients prior to PVR. Of these, 5 patients showed a decrease in QRS duration following PVR; QRS duration was less than 180 msec in 2 patients, and QRS duration remained greater than 180 msec in 3 patients, including 2 patients with diffuse postoperative right ventricular outflow tract hypokinesis. Six patients had coexisting arrhythmias before PVR; 2 patients, atrial tachycardia; 3 patients, premature ventricular contraction; and 1 patient, premature atrial contraction. None of the patients presented with arrhythmia following PVR. Conclusion: The CTR and QRS duration reduced following PVR. However, QRS duration may not decrease below 180 msec after PVR, particularly in patients with right ventricular outflow tract hypokinesis. The CTR and ECG may provide additional clinical information on changes in right ventricular volume and/or pressure in these patients.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.51-60
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• 2010

This study is to examine how Korean speakers realize English stress on the homographic words. Experiments were performed by Korean speakers three times, before stress instruction, immediately after instruction, and six weeks after instruction. First, duration, fundamental frequency, and intensity of the vowel in a stressed syllable of three homographic words produced by Korean speakers were compared with those of native speakers of English. The result shows that when the words were used as nouns, before instruction Korean speakers had shorter duration and lower fundamental frequency in the stressed vowel than the native speakers, which indicates that Korean speakers did not assign the primary stress on the first syllable of the nouns. After instruction, the values of duration and fundamental frequency were increased and the differences between two groups were decreased. Next, the values of these stress features measured three times were analyzed in order to find out how they changed through instruction. The analysis shows that after instruction the values of three features were increased compared to the ones before instruction, and that the biggest change was in duration of the vowel and the next was fundamental frequency. Six weeks after instruction, the values of duration and intensity were decreased than those immediately after instruction. This means that instruction is helpful for Korean speakers to assign the stress for the English homographic words, and that instruction and practice are needed repeatedly.

• Journal of the Korean Geographical Society
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• v.41 no.4 s.115
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• pp.435-456
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• 2006

This study examines the long-term spatial patterns and recent trends of seasonal onsets and durations defined by daily temperatures in South Korea for the period 1973-2004. Spatially, spring and winter onset dates show approximately 44 day and 63 day maximum difference respectively between south and north (Seongsanpo to Daegwallryeong) attributable to the impacts of latitudes and altitudes. In contrast, summer onset, which is more affected by proximity to oceans and altitudes than by latitudes, begins earlier in interior low elevated areas than in the coastal areas but earliest at higher latitudes than Jeiu Island. Five climatic types regarding the seasonal cycles in South Korea are spatially clustered according to the combination of longer seasonal durations. As a reflection of recent climate changes on seasonal cycles in South Korea, winter duration was shortened by 10 days during the post-1988 period due to a late winter onset of 4 days and an early spring onset of 6 days. The winter reduction began in the southern regions of the Korean Peninsula in the mid-1980s and spread northward during the 1990s period, ultimately appearing everywhere. In urbanized cities, where much of the surface is covered with asphalt or concrete, the winter reduction was intensified and summer duration was locally incremented. The reduced winter duration in recent decades shows significant teleconnections with variations of geopotential height (925hPa) in the eastern Arctic region ($0-90^{\circ}E$, $65-85^{\circ}N$) during the cold season. The reduction in winter duration in South Korea agrees with results in overall global warming trends as a climate change signal.