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Article ; Online: Impacts of COVID-19 on Air Quality through Traffic Reduction

Hyemin Hwang / Jae Young Lee

International Journal of Environmental Research and Public Health, Vol 19, Iss 1718, p

2022 Volume 1718

Abstract: In 2020, the first case of COVID-19 was confirmed in Korea, and social distancing was implemented to prevent its spread. This reduced the movement of people, and changes in air quality were expected owing to reduced emissions. In the present paper, the ... ...

Abstract	In 2020, the first case of COVID-19 was confirmed in Korea, and social distancing was implemented to prevent its spread. This reduced the movement of people, and changes in air quality were expected owing to reduced emissions. In the present paper, the impact of traffic volume change caused by COVID-19 on air quality in Seoul, Korea, is examined. Two regression analyses were performed using the generalized additive model (GAM), assuming a Gaussian distribution; the relationships between (1) the number of confirmed COVID-19 cases in 2020–2021 and the rate of change in the traffic volume in Seoul, and (2) the traffic volume and the rate of change in the air quality in Seoul from 2016 to 2019 were analyzed. The regression results show that traffic decreased by 0.00431% per COVID-19 case; when traffic fell by 1%, the PM 10 , PM 2.5 , CO, NO 2 , O 3 , and SO 2 concentrations fell by 0.48%, 0.94%, 0.39%, 0.74%, 0.16%, and −0.01%, respectively. This mechanism accounts for air quality improvements in PM 10 , PM 2.5 , CO, NO 2 , and O 3 in Seoul during 2020–2021. From these results, the majority of the reduction in pollutant concentrations in 2020–2021 appears to be the result of a long-term declining trend rather than COVID-19.
Keywords	COVID-19 ; social distancing ; traffic ; air quality ; Seoul ; generalized additive model ; Medicine ; R
Subject code	290
Language	English
Publishing date	2022-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: A computational model for structural dynamics and reconfiguration of DNA assemblies

Jae Young Lee / Heeyuen Koh / Do-Nyun Kim

Nature Communications, Vol 14, Iss 1, Pp 1-

2023 Volume 12

Abstract: Abstract Recent advances in constructing a structured DNA assembly whose configuration can be dynamically changed in response to external stimuli have demanded the development of an efficient computational modeling approach to expedite its design process. ...

Abstract	Abstract Recent advances in constructing a structured DNA assembly whose configuration can be dynamically changed in response to external stimuli have demanded the development of an efficient computational modeling approach to expedite its design process. Here, we present a computational framework capable of analyzing both equilibrium and non-equilibrium dynamics of structured DNA assemblies at the molecular level. The framework employs Langevin dynamics with structural and hydrodynamic finite element models that describe mechanical, electrostatic, base stacking, and hydrodynamic interactions. Equilibrium dynamic analysis for various problems confirms the solution accuracy at a near-atomic resolution, comparable to molecular dynamics simulations and experimental measurements. Furthermore, our model successfully simulates a long-time-scale close-to-open-to-close dynamic reconfiguration of the switch structure in response to changes in ion concentration. We expect that the proposed model will offer a versatile way of designing responsive and reconfigurable DNA machines.
Keywords	Science ; Q
Subject code	612
Language	English
Publishing date	2023-11-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Implications of Renovated Buildings in Yeonnam-Dong, Seoul, an Area under Commercial Gentrification

Dai Whan An / Jae-Young Lee

Sustainability, Vol 15, Iss 1960, p

2023 Volume 1960

Abstract: We aimed to identify the characteristics of the changes in the buildings and alleyways in Yeonnam-dong, Seoul, where low-rise, residential buildings are being renovated or repurposed into commercial buildings, as well as to investigate their renovations, ...

Abstract	We aimed to identify the characteristics of the changes in the buildings and alleyways in Yeonnam-dong, Seoul, where low-rise, residential buildings are being renovated or repurposed into commercial buildings, as well as to investigate their renovations, repurposes, and sociocultural implications. Thus, we surveyed and classified 149 renovated buildings, investigated the perceptions and ambiance of the area and buildings using a trade area analysis and interviews with visitors and store owners, and uncovered the importance of renovation. Since the early gentrification, a trend of performing renovations that retained the original form of the building from the initial renovation stage was seen; this created an ambiance of nostalgia, naturalness, and authenticity, along with the urban conditions of low-rise, residential buildings in Yeonnam-dong, a representative undeveloped area. These renovated buildings reflect the social status, taste, and practice of gentrifiers, and they reveal a hybridization of the past and present, Korean circumstances and exotic cultures, and residential and commercial buildings. As commercialization progressed, renovated buildings vastly differing from the original and displaying active commercial characteristics were seen. Our findings imply that the area’s early ambiance, which had an air of “distinctiveness”, has lost its personality and begun to generalize. Thus, numerous gentrifiers have been replaced and several aspects of renovation have changed that the visitors are aware of.
Keywords	commercial gentrification ; renovation ; authenticity ; commerciality ; ambiance ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	720
Language	English
Publishing date	2023-01-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: When Humble Leaders Enhance Employee Job Crafting

SuJin Son / Jae Young Lee

SAGE Open, Vol

The Role of Gender and Trust in Leaders

2023 Volume 13

Abstract: The study aimed to investigate the main effect of leader humility on job crafting and the potential three-way interaction effect between leader humility, trust in leaders, and gender on job crafting. Data were collected from 158 employees in two ... ...

Abstract	The study aimed to investigate the main effect of leader humility on job crafting and the potential three-way interaction effect between leader humility, trust in leaders, and gender on job crafting. Data were collected from 158 employees in two organizations in South Korea. In order to analyze the proposed hypotheses, we used hierarchical regression analysis and PROCESS macro (Model 3) in SPSS with 5,000 bootstrap samples. The results revealed that leader humility influences job crafting, and the impact of leader humility on task crafting depends on the level of trust. In particular, higher trust between a leader and employee indicates a more positive relationship between leader humility and the employee’s task crafting behaviors. Furthermore, a moderated moderation effect was discovered of gender on the two-way interaction effect. The results of this study highlight that leader humility plays an important role for employees’ job crafting behavior particularly when they have highly trusting relationships with their leaders. In addition, this study provides a comprehensive understanding of leader humility’s effect on job crafting by investigating the role of gender.
Keywords	History of scholarship and learning. The humanities ; AZ20-999 ; Social Sciences ; H
Subject code	650
Language	English
Publishing date	2023-07-01T00:00:00Z
Publisher	SAGE Publishing
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Echocardiographic assessment of brain sparing in small-for-gestational age infants and association with neonatal outcomes

Ju Ae Shin / Jae Young Lee / Sook Kyung Yum

Scientific Reports, Vol 13, Iss 1, Pp 1-

2023 Volume 10

Abstract: Abstract Brain sparing is an adaptive phenomenon (redistribution of blood flow to the brain) observed in fetuses exposed to chronic hypoxia, who are at risk of intrauterine growth restriction. Here, we assessed the blood flow distribution during the ... ...

Abstract	Abstract Brain sparing is an adaptive phenomenon (redistribution of blood flow to the brain) observed in fetuses exposed to chronic hypoxia, who are at risk of intrauterine growth restriction. Here, we assessed the blood flow distribution during the early neonatal period (< 7 days of life) using echocardiography, and evaluated the impact of brain-sparing on postnatal course and neurodevelopmental outcomes. This retrospective study included 42 small-for-gestational age (SGA) infants [further classified into asymmetric SGA (a-SGA, n = 21) and symmetric SGA (s-SGA, n = 21) groups according to their birth head circumference percentiles], and 1: 2 matched appropriate-for-gestational age (AGA) infants (n = 84) admitted to the neonatal intensive care unit. Left ventricular (LV) stroke volume, LV cardiac output (LVCO), upper body blood flow (UBBF), and UBBF/LVCO ratio (%) were significantly higher in both a-SGA and s-SGA infants than in AGA infants. Both a-SGA and s-SGA groups consisted predominantly of infants with higher UBBF/LVCO (%). A UBBF/LVCO ≥ 58.2% (3rd interquartile range) was associated with a later need for rehabilitative therapy after discharge. In summary, brain-sparing effect may continue during the early postnatal life in SGA infants, and may be a promising marker to detect future adverse neurodevelopmental outcomes.
Keywords	Medicine ; R ; Science ; Q
Subject code	610
Language	English
Publishing date	2023-06-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Evaluation of roadside air quality using deep learning models after the application of the diesel vehicle policy (Euro 6)

Hyemin Hwang / Sung Rak Choi / Jae Young Lee

Scientific Reports, Vol 12, Iss 1, Pp 1-

2022 Volume 9

Abstract: Abstract Euro 6 is the latest vehicle emission standards for pollutants such as CO, NO2 and PM, that all new vehicles must comply, and it was introduced in September 2015 in South Korea. This study examined the effect of Euro 6 by comparing the measured ... ...

Abstract	Abstract Euro 6 is the latest vehicle emission standards for pollutants such as CO, NO2 and PM, that all new vehicles must comply, and it was introduced in September 2015 in South Korea. This study examined the effect of Euro 6 by comparing the measured pollutant concentrations after 2016 (Euro 6–era) to the estimated concentrations without Euro 6. The concentration without Euro 6 was estimated by first modeling the air quality using various environmental factors related to diesel vehicles, meteorological conditions, temporal information such as date and precursors in 2002–2015 (pre–Euro 6–era), and then applying the model to predict the concentration after 2016. In this study, we used both recurrent neural network (RNN) and random forest (RF) algorithms to model the air quality and showed that RNN can achieve higher R2 (0.634 ~ 0.759 depending on pollutants) than RF, making it more suitable for air quality modeling. According to our results, the measured concentrations during 2016–2019 were lower than the concentrations predicted using RNN by − 1.2%, − 3.4%, and − 4.8% for CO, NO2 and PM10. Such reduction can be attributed to the result of Euro 6.
Keywords	Medicine ; R ; Science ; Q
Subject code	333
Language	English
Publishing date	2022-12-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Estimation of Heat-Attributable Mortality Using the Cross-Validated Best Temperature Metric in Switzerland and South Korea

Jae Young Lee / Martin Röösli / Martina S. Ragettli

International Journal of Environmental Research and Public Health, Vol 18, Iss 6413, p

2021 Volume 6413

Abstract: This study presents a novel method for estimating the heat-attributable fractions (HAF) based on the cross-validated best temperature metric. We analyzed the association of eight temperature metrics (mean, maximum, minimum temperature, maximum ... ...

Abstract	This study presents a novel method for estimating the heat-attributable fractions (HAF) based on the cross-validated best temperature metric. We analyzed the association of eight temperature metrics (mean, maximum, minimum temperature, maximum temperature during daytime, minimum temperature during nighttime, and mean, maximum, and minimum apparent temperature) with mortality and performed the cross-validation method to select the best model in selected cities of Switzerland and South Korea from May to September of 1995–2015. It was observed that HAF estimated using different metrics varied by 2.69–4.09% in eight cities of Switzerland and by 0.61–0.90% in six cities of South Korea. Based on the cross-validation method, mean temperature was estimated to be the best metric, and it revealed that the HAF of Switzerland and South Korea were 3.29% and 0.72%, respectively. Furthermore, estimates of HAF were improved by selecting the best city-specific model for each city, that is, 3.34% for Switzerland and 0.78% for South Korea. To the best of our knowledge, this study is the first to observe the uncertainty of HAF estimation originated from the selection of temperature metric and to present the HAF estimation based on the cross-validation method.
Keywords	temperature-mortality association ; DLNM ; cross validation ; Medicine ; R
Subject code	541 ; 310
Language	English
Publishing date	2021-06-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: First report on the persist time of the free radical produced by shock wave pulses employed in clinical ESWL

Min Joo Choi / Jae-Young Lee / Eun-Joo Park

Ultrasonics Sonochemistry, Vol 83, Iss , Pp 105927- (2022)

2022

Abstract: The shock wave used in extracorporeal shock wave lithotripsy (ESWL) induces strong cavitation and generates a large amount of free radicals (FR). In order to evaluate the harmfulness of FR in the ESWL, information on the incidence and persist time of FR ... ...

Abstract	The shock wave used in extracorporeal shock wave lithotripsy (ESWL) induces strong cavitation and generates a large amount of free radicals (FR). In order to evaluate the harmfulness of FR in the ESWL, information on the incidence and persist time of FR caused by shock waves is required. FR markers can estimate the amount of FR generated, but not how long the FRs will survive. The OH* FR generated by the ESWL shock wave reacts with luminol and emits blue light, which is called sonochemical luminescence (SCL) phenomenon. In this study, FR generation and persist time were measured by recording SCL phenomenon with a sensitive photomultiplier tube (PMT) that responds in nanoseconds. As a result of measurement with the PMT, when the electromagnetic shock wave used in clinical practice was irradiated to the luminol solution, the amount of light emitted per unit time reached its maximum value within a very short time (< ∼600us) and then exponentially decreased for a long time (∼several hundred ms). The measured FR persist time reaches a maximum of 1000 ms. As the output setting of the shock wave generator increases, the minimum or average FR persist time increases, but the maximum value does not show a high correlation with the output setting. The amount of generated FR shows a very high correlation with the shock wave setting, and when the setting is changed from low to high, it increases very sensitively, rapidly and non-linearly. In order to reduce the risk of FR in patient treatment using lithotripsy, the output setting of the shock wave should be minimized, and the interval between the shock wave pulses should be sufficiently larger than the FR persist time. Therefore, it is recommended to avoid increasing the output setting and setting the shock wave irradiation frequency below 1 Hz to shorten the treatment time in clinical practice. For the purpose of formulating these recommendations, additional studies on the generation and persist time of FR depending on the shock wave generation method and set conditions ...
Keywords	ESWL ; Shock wave therapy ; Hydroxyl radical ; Free radical ; Persist time ; Safety ; Chemistry ; QD1-999 ; Acoustics. Sound ; QC221-246
Subject code	535
Language	English
Publishing date	2022-02-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Mechanical Integrity Analysis of a Printed Circuit Heat Exchanger with Channel Misalignment

Armanto P. Simanjuntak / Jae Young Lee

Applied Sciences, Vol 10, Iss 6, p

2020 Volume 2169

Abstract: Printed circuit heat exchangers (PCHEs), which are used for thermal heat storage and power generation, are often subject to severe pressure and temperature differences between primary and secondary channels, which causes mechanical integrity problems. ... ...

Abstract	Printed circuit heat exchangers (PCHEs), which are used for thermal heat storage and power generation, are often subject to severe pressure and temperature differences between primary and secondary channels, which causes mechanical integrity problems. PCHE operation may result in discontinuity, such as channel misalignment, due to non-uniform thermal fields in the diffusion bonding process. The present paper analyzes the mechanical integrity, including the utilization factors of stress and deformation under various channel misalignment conditions. The pressure difference of the target PCHE is 19.5 MPa due to the high pressure (19.7 MPa) of the steam channel in the Rankine cycle and the low pressure (0.5 MPa) of molten salt or liquid metal in the primary channel. Additionally, the temperature difference between channels is around 25 °C, however the average temperature is around 500 °C. The PCHE has a relatively large primary channel measuring approximately 3 x 3 mm, and a steam channel measuring 2 x 1.5 mm. The finite element method (FEM) is applied to determine the stress by changing the misalignment to below 30% of the primary channel width. It was found that the current PCHE is operable up to 700 °C in terms of the ASME code under these design conditions. Additionally, the change of utilization factor due to the misalignment increases, but is still under the ASME acceptance criteria of 700 °C; however, it violates the criteria at 725 °C, which is the allowable temperature condition. Therefore, the mechanical integrity of the PCHE with low-pressure molten salt or liquid metal and a high-pressure steam channel is acceptable in terms of utilization factor.
Keywords	pche ; fem ; misalignment ; stress ; channel ; utilization factor ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
Subject code	600
Language	English
Publishing date	2020-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Spatial and temporal changes in moth assemblages along an altitudinal gradient, Jeju-do island

Sei-Woong Choi / Jeong-Seop An / Jae-Young Lee / Kyung Ah Koo

Scientific Reports, Vol 12, Iss 1, Pp 1-

2022 Volume 13

Abstract: Abstract Montane species on islands attract attention due to their small and isolated populations and limited dispersal potential, making them vulnerable to extinction. We investigated the diversity pattern of moth assemblages over the 12-years-period ( ... ...

Abstract	Abstract Montane species on islands attract attention due to their small and isolated populations and limited dispersal potential, making them vulnerable to extinction. We investigated the diversity pattern of moth assemblages over the 12-years-period (2009–2020) at 11 study plots on an island mountain (Mount Hallasan, Jeju-do Island, South Korea) to assess the changes in the moth assemblages in terms of species composition, richness, and abundances. We expected to find a decline in the number of species at these sites, given the reported decline in similar taxa in other temperate regions, such as Europe and North America. In contrast, we found that the numbers of species and individuals of moth populations on the island mountain have not significantly changed, except at the high-elevation sites, where the number of species has increased. Our results also show that the numbers of species and individuals are closely related to energy availability, actual evapotranspiration. Moreover, we found that the species composition during the study period has not been greatly changed, except at the lowermost and uppermost elevations. The mechanism driving this high dissimilarity of moth assemblages differed: the low-elevation site experienced high temporal turnover, and the high elevation sites also experienced high temporal turnover and nestedness resulting from active species replacement due to a recent forest fire and vegetation changes and the geographic and ecological constraints of the high elevations. To date, the moth species diversity of the temperate forests of the island mountain is not showing a drastic change. However, we observed that the moth assemblages had changed the number of species and individuals at low and high elevations. Given the biological and ecological limitations of moths (ectothermic organisms with limited habitat range) and considering the results of our study, we infer that climate change has impacted the diversity and species composition of moths on the island mountain.
Keywords	Medicine ; R ; Science ; Q
Subject code	590
Language	English
Publishing date	2022-11-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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