• Journal of Korea Water Resources Association
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• v.47 no.11
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• pp.985-996
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• 2014

When designing hydraulic structures, the chosen method of time distribution in a hyetograph is highly significant. There are several methods used for measuring time distribution. In the case of Huff (1967), which is widely used in Korea, the Ministry of Construction and Transportation (MOCT, 2000), and the Ministry of Land, Transport and Maritime Affairs (MOLTMA, 2011) have long been increasing their use of this method. The MOLTMA uses the conventional Huff method's measurement of 1 inch (25.4 mm) as the threshold. Many researchers have pointed out that this method often leads to underestimation, because of the excessive flatness. Therefore, for this study, a new time distribution method was developed to analyze only extreme rainfall events-those over the standard of severe rainstorms (that is, more than 30 mm per hour or 80 mm per day)-and that was verified using a rainfall-runoff model and applying it to a real basin.

• Journal of the Korean association of regional geographers
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• v.17 no.5
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• pp.505-520
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• 2011

This study is aimed to examine the change on extreme precipitation events in South Korea. The country is divided into six basins, and seven extreme precipitation indices-related to heavy rainfall are analyzed at sixty weather stations. The increasing trend in amount of heavy rainfall is more stable than that in days of heavy rainfall. The increasing trend is the most stable when days of rainfall are more than 50 mm, or rainfall is over the 95th percentile. The precipitation indices-related to heavy rainfall was mostly increasing during analysis period. Especially, basins of the Han river, the upper Nakdong river, and the Eastern coast show significantly increasing trends compared to the other basins. However, the increasing trends of the Geum river and the Seomjin river are not statistically significant. Heavy rainfall events had stably increased in the Han and the Nakdong rivers since the mid-1970s. However, the number of stably increasing regions has decreased since the mid-2000s. It means that the frequency and intensity of the recent heavy rainfall become more irregular.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.7
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• pp.1066-1077
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• 2002

The Purposes of this study were 1) to identify the effects of clothing involvement on deal Proneness, store images related to promotions and perceived shopping value, and 2) to reveal the effects of antecedent variables on the consumer satisfaction. The data were collected from 624 female consumers living in Seoul, Korea via self-administered questionnaires and were analyzed by frequency, factor analysis, multiple regression analysis and path analysis. The results of the study were as follows : (1) Among the factors related to clothing involvement deal proneness, store images of promotions and perceived shopping values, Clothing importance, Shopping interest Fashion interest and all three factors of deal proneness had the effect on perceived hedonic shopping values. Clothing importance, Prudent purchase, Shopping interest store images related to promotions had the effects on perceived hedonic shopping values. And Prudent purchase had the positive effects and store images related to Display had the negative effects on perceived negative shopping values. (2) From the resulted of analyzing the effects of antecedent variables on consumer satisfaction, Sweepstakes/gifts proneness, store images related to Price discount/events and Display, perceived hedonic and utilitarian shopping values positive]y influenced the consumer satisfaction. Store images related to Price discount/events had the most significant effects on consumer satisfaction. From the results of path analysis, clothing involvement had the effects on consumer satisfaction indirectly through deal proneness, store images related to promotions and perceived shopping values.

• Environmental Engineering Research
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• v.19 no.3
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• pp.229-240
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• 2014

Rain events are extremely important for phosphorus (P) dynamics in rivers since large portions of annual river P loads can be transported in particulate forms during only a few major events. Despite their importance, a precise estimation of P contribution in river sediments after rainy seasons has rarely been reported. This study estimated the longitudinal variation in the concentrations of different inorganic P fractions in bed sediments of the South Han River over a rainy season, through using the sequential extraction method. Non-apatite P was the dominant form, representing more than 60% of total inorganic P (TIP) content in sediments. Although no significant variation of TIP contents was observed, the proportion of bioavailable P in TIP pools decreased after the rainy season. The concentrations of individual inorganic P fractions ($NH_4Cl-P$, $NH_4F-P$, NaOH-P, and $H_2SO_4-P$) were significantly different across sites and after the rainy season (p < 0.05, two-way ANOVA). $NH_4F-P$ and NaOH-P concentrations in sediments increased in a downstream direction. After the rainy season, $NH_4Cl-P$ concentrations in sediments decreased whereas $NH_4F-P$ and $H_2SO_4-P$ concentrations increased. The redistribution of individual P fractions in sediments observed after rainy seasons were possibly due to the changing contribution of various sources of runoff and the variation in flow related particle size. Current estimation of P in bed sediments of the South Han River suggests a lower potential of internal P loading from sediments after the rainy season.

• Nuclear Engineering and Technology
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• v.21 no.1
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• pp.1-11
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• 1989

Numerous losses of decay heat removal capability have occurred at U during stutodwn while its significance to safety is needless to say. A study is carried out as an attempt to assess what could be done to lower the frequency of these events and to mitigate their consequences in the unlikely event that one occurs. The shutdown risk model is developed and analyzed using Event/Fault Tree for the typical pressurized water reactor. The human cognitive reliability (HCR) model, two-stage bayesian approach and staircase function model are used to estimate human reliability, initiating event frequency and offsite power non-recovery probability given loss of offsite power, respectively. The results of this study indicate that the risk of a Pm at shutdown is not much lower than the risk when the plant is operating. By examining the dominant accident sequences obtained, several design deficiencies are identified and it is found that some proposed changes lead to significant reduction in core damage frequency due to loss of cooling events.

• Geomechanics and Engineering
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• v.22 no.5
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• pp.385-396
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• 2020

A uniaxial compression test was performed to analyse the mechanical properties and macroscale and mesoscale failure mechanisms of sandstone with pyrite concretions. The effect of the pyrite concretions on the evolution of macroscale cracks in the sandstone was further investigated through numerical simulations with Particle Flow Code in 2D (PFC2D). The results revealed that pyrite concretions substantially influence the mechanical properties and macroscale and mesoscale failure characteristics of sandstone. During the initial loading stage, significant stress concentrations occurred around the edges of the pyrite concretion accompanied by the preferential generation of cracks. Meanwhile, the events and cumulative energy counts of the acoustic emission (AE) signal increased rapidly because of friction sliding between the concretion and sandstone matrix. As the axial stress increased, the degree of the stress concentration remained relatively unchanged around the edges of the concretions. The cracks continued growing rapidly around the edges of the concretions and gradually expanded toward the centre of the sample. During this stage, the AE events and cumulative energy counts increased quite slowly. As the axial stress approached the peak strength of the sandstone, the cracks that developed around the edges of the concretion started to merge with cracks that propagated at the top-left and bottom-right corners of the sample. This crack evolution ultimately resulted in the shear failure of the sandstone sample around the edges of the pyrite concretions.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.158-158
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• 2018

Drought is a recurrent natural hazard in Bangladesh. It has significant impacts on agriculture, environment, and society. Well-timed information on the onset, extent, intensity, duration, and impacts of drought can mitigate the potential drought-related losses. Thus, drought characteristics need to be explained in terms of frequency, severity, and duration. This paper aims to characterize the spatial and temporal pattern of meteorological drought using EDI and illustrated drought severity over Bangladesh. Twenty-seven (27) station-based daily rainfall data for the study period of 1981-2015 were used to calculate the EDI values over Bangladesh. The evaluation of EDI is conducted for 4 sub-regions over the country to confirm the historical drought record-developed at the regional scale. The finding shows that on average, the frequency of severe to extreme drought is approximately 0.7 events per year. As a result of the regional analysis, most of the recorded historical drought events were successfully detected during the study period. Additionally, the seasonal analysis showed that the extreme droughts were frequently hit in northwestern, middle portion of the eastern and small portion of central parts of Bangladesh during the Kharif(wet) and Rabi(dry) seasons. The severe drought was affected recurrently in the central and northern regions of the country during all cropping seasons. The study also points out that the northern, south-western and central regions in Bangladesh are comparatively vulnerable to both extreme and severe drought event. The study showed that EDI would be a useful tool to identify the drought-prone area and time and potentially applicable to the climate change-induced drought evolution monitoring at regional to the national level in Bangladesh. The outcome of the present study can be used in taking anticipatory strategies to mitigate the drought damages on agricultural production as well as human sufferings in drought-prone areas of Bangladesh.

• Journal of Biomedical Engineering Research
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• v.40 no.5
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• pp.171-178
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• 2019

This study was conducted to observe the differences in perspective of medical device adverse events and report exchange for domestic stakeholders. The post-market surveillance of medical device not only improves the usability and functionality of the device but also identifies new or growing risks caused by the device. APEC (Asia-Pacific Economic Cooperation) have established and operated post-market surveillance systems for medical devices based on IMDRF (International Medical Device Regulators Forum) and GHTF (Global Harmonization Task Force) guidelines. However, there are significant gaps in many aspects. It is essential to apply harmonized guidelines internationally but also to interpret and apply the guidelines consistently to report and exchange medical device adverse event in domestic. This study retrospectively analyzed the results of surveys conducted by providing examples of the adverse events and guidelines for post-market surveillance. The results of the study showed that there was a considerable difference in the judgment on the phase of using medical device for patient. In the case of medical device adverse event, different opinions shown according to knowledge and experience. Education and training are needed to have a harmonized perspective on the reporting and exchanging international guidelines of the adverse event for domestic stakeholders.

• Journal of The Korean Society of Clinical Toxicology
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• v.17 no.2
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• pp.86-93
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• 2019

Purpose: The objective was to determine the association between PaCO₂ and adverse cardiovascular events (ACVEs) in carbon monoxide (CO)-poisoned patients. Methods: This retrospective study included 194 self-breathing patients after CO poisoning with an indication for hyperbaric oxygen therapy and available arterial blood gas analysis at presentation and 6 hours later. The baseline characteristics and clinical course during hospitalization were collected and compared. The mean PaCO₂ during the first 6 hours after presentation was calculated. Results: The incidence rates of moderate (30 mmHg< PaCO₂ <35 mmHg) or severe (PaCO₂ ≤30 mmHg) hypocapnia at presentation after acute CO poisoning were 40.7% and 26.8%, respectively. The mean PaCO₂ during the first 6 hours was 33 (31-36.7) mmHg. The incidence of ACVEs during hospitalization was 50.5%. A significant linear trend in the incidence of ACVEs was observed across the total ranges of PaCO₂ variables. In multivariate regression analysis, mean PaCO₂ was independently associated with ACVEs (OR 0.798 (95% CI 0.641-0.997)). Conclusion: Mean PaCO₂ during the first 6 hours was associated with increased ACVEs. Given the high incidence of ACVEs and PaCO₂ derangement and the observed association between PaCO₂ and ACVEs, this study suggests that 1) PaCO₂ should be monitored at the acute stage to predict and/or prevent ACVEs; and 2) further study is needed to validate this result and investigate early manipulation of PaCO₂ as treatment.

• Korean Journal of Clinical Pharmacy
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• v.31 no.3
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• pp.237-246
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• 2021

Background: Pembrolizumab, an anti-cancer drug, is known to increase the activity of the immune system, leading to side effects called immune-related adverse events (irAE), including type 1 diabetes. This study analyzed the correlation between blood glucose level and pembrolizumab administration and investigated the covariates that affect those changes in cancer treatment. Methods: The information of 133 adult cancer patients was obtained from the electronic medical record (EMR) to identify the changes in random blood glucose (RBG) levels during the pembrolizumab treatment. Subjects were classified into subgroups according to their baseline RBG level, history of diabetes, and the use of steroids, and linear regression analysis was conducted. In addition, a secondary analysis was performed within the group of subjects having a strong correlation to glycemic change, which was based on the Pearson correlation coefficient being less than -0.7 or greater than +0.7. Univariate and multivariate logistic regressions were conducted to identify the risk factors to glycemic increase. Results: The RBG level tended to descend without significant differences in total patients during the administration period of pembrolizumab. Despite the insignificance, the logistic regression analysis presents that the odds ratios of baseline RBG less than 130 mg/dL, prophylactic steroid use, and higher dose of pembrolizumab per cycle (mg/kg/cycle) were greater than 1. Conclusions: Prophylactic administration of steroids and a higher dose of pembrolizumab per cycle may increase the blood glucose level as irAE in cancer patients with a strong tendency to glycemic change.