Site In Seoul Research Articles

위험성평가의 실효성이 건설근로자의 안전행동에 미치는 영향

The Ministry of Employment and Labor, in November 2022, announced a major accident reduction roadmap, aiming to reduce the fatality and injury rate to the level of OECD advanced countries by revamping risk assessments as a key tool for accident prevention and recurrence prevention. They cited the difficulty and lack of proper implementation of risk assessments, as well as low worker participation, as major issues. This study aims to investigate how the effectiveness of risk assessment influences workers' safety behavior, and contribute to the foundational data for enhancing the effectiveness of risk assessments. The study surveyed 250 workers at construction sites in Seoul, Gyeonggi to examine the relationship between the effectiveness of risk assessments and safety behavior, as well as the mediating effects of perceived risk factors. Data analysis was conducted using the statistical analysis program JAMOVI, and structural equation modeling was employed to verify the hypotheses. The results indicated that the effectiveness of risk assessments significantly influenced safety behavior (β=0.135, p=0.01), and perceived risk factors played a mediating role in the relationship between the effectiveness of risk assessments and safety behavior (β=0.269, p<.001). These findings suggest that enhancing the effectiveness of risk assessments requires providing workers with education on risk assessments and utilizing consulting services from external safety experts or safety organizations.

Chemical composition and source apportionment of PM2.5 in Seoul during 2018–2020

Air pollution, particularly high ambient particulate matter (PM) concentrations, poses a serious public health concern in South Korea. This study analyzed 139 daily PM2.5 samples collected from an urban site in Seoul between March 2018 and January 2020. This study aimed to quantify the chemical composition of PM2.5 and identify the source characteristics. The average PM2.5 mass concentration for the entire study period was 25.3 μg m−3. The chemical composition was dominated by ionic particles (13.2 μg m−3, 52%), carbonaceous particles (7.0 μg m−3, 28%), and trace elements (0.5 μg m−3, 2%). The Positive Matrix Factorization (PMF) model was employed to identify PM2.5 sources using quality-controlled sampling data after eliminating factors that could adversely affect the modeling. Seven sources were resolved through PMF, applying a trial-and-error method to determine the optimal number of sources. The PMF modeling results indicated that secondary sulfate (28%) was the largest contributor, followed by internal factors (23%), secondary nitrate (19%), soil (14%), biomass burning (9%), and aged sea salt (7%). As an additional case study, the analysis of backward trajectories for the winter of 2018, which had the highest PM2.5 concentrations, revealed that the air current carrying PM2.5 had passed from the northwest region of Seoul. Particulary, source identification for this winter case resulted in the highest secondary nitrate across all study periods. This more specific interpretation of the pollutant characteristics of PM2.5 in Seoul could aid in developing effective control strategies and policies for air pollution mitigation.

Nocturnal downward transport of NO3 radical from the residual layer to a surface site by the mountain breeze in Seoul, South Korea

Using the long-path differential optical absorption spectroscopy (LP-DOAS) technique, the nocturnal mixing ratios of NO3 radicals were measured at an urban site in Seoul, South Korea, from May 13 to June 12, 2022. The primary objectives of the study were to estimate the NO3 radical concentration in the nighttime boundary layer and to examine the variations in their generation and loss over time, including an evaluation of their sources and sinks. The observed mean NO3 mixing ratios and lifetimes were 16 pptv and 73 s, respectively. NO3 concentrations and lifetimes were closely associated with their production, involving O3 and NO2, as well as the loss processes regulated by NO, VOCs, and aerosol surface area. Applying the steady-state assumption for NO3 and N2O5, the mean N2O5 uptake coefficient on the aerosol surface for the entire period was 0.031. When foggy nights were excluded from the analysis, the uptake coefficient decreased to 0.025. These values are within the higher range of the results reported in other studies. High relative humidity, which averaged 75% at night throughout the collection period, favored high N2O5 uptake coefficients. NO3 concentrations generally peaked shortly after sunset and gradually declined until sunrise. However, we frequently observed distinct increases in NO3 throughout the early morning hours, especially during clear nights, when local circulation with the westerly mountain breeze prevailed at the research site. The mountain breeze transported residual air downward, resulting in 110% and 38% higher NO3 and O3 levels at the sampling locations, respectively, compared to normal conditions. This additional source of nocturnal radicals and O3 has consequences for increased secondary aerosols and O3 production, particularly at urban surface levels where they are readily depleted in the early morning hours. To this end, a more thorough examination is required to measure N2O5 and a larger spectrum of VOCs species, as these parameters are crucial for nighttime radical budgets, secondary aerosols, and O3 generation in cities like Seoul.

A Study of the Foremen’s Influence on the Safety Behavior of Construction Workers Based on Cognitive Theory

In this study, a behavioral influence model based on cognitive theory was developed to investigate foremen’s influences on construction workers’ safety behavior. In the model, three foreman behaviors were considered, such as leading by example (LE), safety teaching (ST), and safety monitoring (SM). Five cognitive stages of a worker are also considered in the model, such as situation awareness, safety knowledge, subjective norm, safety attitude, and taking action. To obtain empirical data for the model parameters, a survey was conducted on a construction site in Seoul, South Korea, where the foreman–worker behavioral interactions and workers’ unsafe behavior of taking shortcuts were observed. The model was established as Agent-Based Modeling (ABM) using AnyLogic software. Four scenarios of foremen’s behavior were simulated using the model. The result shows that LE behavior has a positive, but weak significant influence on workers’ safety behavior. ST was found to have a positive and the most significant influence on workers’ safety behavior. Moreover, it should be provided with appropriate safety monitoring to maximize its effectiveness. The research findings promote stakeholders’ understanding of the influence of foremen on workers’ safety behavior and lead to the formation of informed policies and future research directions in the study field.

Interface as the site of infrastructural change

This study contributes to critical infrastructure literature by investigating people’s evolving interactions with surveillance infrastructure at the sites of ‘interface’, specifically focusing on the tracing infrastructure called Electronic Entry Register, devised by the South Korean government during the coronavirus disease 2019 (COVID-19) pandemic. Highlighting the significance of the infrastructure’s ‘interface’ as the site of agential interactions that engender new relations, this paper illustrated the diverse ways in which the structural organisations of tracing infrastructure transformed continually and the resultant meanings of surveillance shifted. To this end, a sequence of field research comprising walking interviews, observations, and sit-in interviews was conducted with 11 research participants across various urban sites in Seoul, a city with one of the highest penetration rates of smartphone use. This situated investigation within the geographical context of high sociotechnical potency is noteworthy because urban infrastructuring increasingly invites digital mediation. The empirical evidence demonstrates how the micro-struggles at the interface sites engendered significant infrastructural changes, which in turn reshaped the lived experiences of surveillance. The results flag the need to attend to the conceptual and analytical significance of ‘interface’ in studying digital infrastructure and reflect on how unfolding sociotechnical relations could express digital infrastructure differently.

‘I’ve left enough data’: Relations between people and data and the production of surveillance

Exploring emergent relations between data-producing individuals and their data products, this study aims to contribute to the ongoing scholarly discussion on agencies in data practices. It focuses on shifts in surveillance structure in the era of Big Data, in which the individual becomes both a subject and an object in the production of data surveillance. Drawing on the concept of the ‘dividual’, the study analyses data practices for a tracing system invented by the South Korean government during the COVID-19 pandemic, with findings from field research conducted with 11 research participants in various urban sites in Seoul. Highlighting how the tracing system positioned surveillance ‘in the hands of citizens’, the study exposes the complexities of the relations that the participants formed with the data they produced, and how they reflexively reappropriated their practices through alterations and deflections on the basis of their tacit knowledge and imaginaries concerning digital data and their constituent positions in the knowledge production system. The resultant expression of surveillance was directly shaped by the evolving relationship between the producers (participants) and products (digital data). The study proposes that an intersectional focus on surveillance and critical data studies, with close attention to ordinary people's relations with data, has the capacity to inquire into the politics of data more fully.

Effects of Road Components and Roadside Vegetation on Temperature Reduction in Seoul Considering Air, Wet-Bulb Globe, and Surface Temperatures

Urbanization has resulted in high temperatures in cities, which are exacerbated by an increase in urban impervious surfaces (road space). This study investigated the effect of urban road characteristics on roadside temperature. Different temperature indices were measured at four sites in Seoul with different road designs by using weather measuring devices and infrared thermal cameras. The differences between air and roadside air temperatures decreased from site 1 (no vegetation) to site 4 (roadside trees and vegetated medians). The analysis results showed that roadside wet-bulb globe and surface thermal temperatures sensitively changed according to road characteristics, unlike air temperature. The lowest temperatures were consistently observed at site 4. This cooling tendency was the strongest in the afternoon, which indicates the effectiveness of vegetation for preventing the commonly observed temperature rise in the afternoon. That is, roadside trees and vegetation in the median strip can prevent temperature rise and contribute to urban temperature reduction. Therefore, more roadside trees and median planting, as well as taller trees and denser vegetation along roads, can be used to provide a greater reduction of roadside temperatures and to improve urban climates.

Characteristics of volatile organic compounds in the metropolitan city of Seoul, South Korea: Diurnal variation, source identification, secondary formation of organic aerosol, and health risk

Atmospheric volatile organic compounds (VOCs) in Seoul, the capital of South Korea, have attracted increased attention owing to their emission, secondary formation, and human health risk. In this study, we collected 24 hourly samples once a month at an urban site in Seoul for a year (a total of 288 samples) using a sequential tube sampler. Analysis results revealed that toluene (9.08 ± 8.99 μg/m3) exhibited the highest annual mean concentration, followed by ethyl acetate (5.55 ± 9.09 μg/m3), m,p-xylenes (2.79 ± 4.57 μg/m3), benzene (2.37 ± 1.55 μg/m3), ethylbenzene (1.81 ± 2.27 μg/m3), and o-xylene (0.91 ± 1.47 μg/m3), indicating that these compounds accounted for 77.8–85.6% of the seasonal mean concentrations of the total (Σ59) VOCs. The concentrations of the Σ59 VOCs were statistically higher in spring and winter than in summer and fall because of meteorological conditions, and the concentrations of individual VOCs were higher during the daytime than nighttime owing to higher human activities during the daytime. The conditional bivariate probability function and concentration weighted trajectory analysis results suggested that domestic effects (e.g., vehicular exhaust and solvents) exhibited a dominant effect on the presence of VOCs in Seoul, as well as long-range atmospheric transport of VOCs. Further, the most important secondary organic aerosol formation potential (SOAFP) compounds included benzene, toluene, ethylbenzene, and m,p,o-xylenes, and the total SOAFP of nine VOCs accounted for 5–29% of the seasonal mean PM2.5 concentrations. The cancer and non-cancer risks of the selected VOCs were below the tolerable (1 × 10−4) and acceptable (Hazard quotient: HQ < 1) levels, respectively. Overall, this study highlighted the feasibility of the sequential sampling of VOCs and hybrid receptor modeling to further understand the source–receptor relationship of VOCs.

Improving PMF source reconciliation with cluster analysis for PM2.5 hourly data from Seoul, Korea

Hourly sampling data for PM2.5 level in 2018 were obtained from intensive monitoring sites in Seoul, Korea. After proper data treatment, 6083 (69.4%) of 8760 raw hourly samples of 24 chemical species were used for positive matrix factorization (PMF) modeling. The dataset was separated into 12 monthly sub-datasets to allow for 12 individual PMF models, and a hierarchical cluster analysis was used for source allocation. We identified 12 sources and estimated their monthly contributions using a source reconciliation process. The proportional annual contributions for the 12 sources were in the order of secondary nitrate (22.8%) > secondary aerosol (21.3%) > mobile (18.4%) > soil (5.5%) > incineration (5.5%) > sea-salt (5.3%) > industry (4.7%) > coal combustion (4.4%) > biomass burning (3.6%) > oil combustion (3.0%) > brake and tire wear (2.8%) > bromine-related combustion (2.6%). The improved source reconciliation process allows for a larger number of sources, clearly specified ambiguous sources, and determination of minor site-specific sources. The study presents an emerging technique for enhancing the pragmatic use of receptor models.

Spatiotemporal inhomogeneity of total column NO2 in a polluted urban area inferred from TROPOMI and Pandora intercomparisons

ABSTRACT The spatiotemporal inhomogeneity of the total column NO2 amounts (TCN) in the Seoul Metropolitan Area (SMA), Korea, was quantitatively assessed through year-round (October 2019–May 2021) TROPOMI and ground-based Pandora measurements. The average TCN over the SMA was comparable to that of major Chinese megacities, being consistently high (> 0.8 DU; Dobson Unit) during the daytime (10–17 local standard time). The autocorrelation scores of the Pandora-measured TCNs demonstrated high temporal variability attributed to the spatial inhomogeneity of NO2 emissions within the SMA and near-surface advection. Accordingly, the adequate temporal collocation range for Pandora measurements for the intercomparison with the satellite sensors was considered to be ± 5 min to avoid significant uncertainty from the temporal variability (RMSE < 0.1 DU, R2 > 0.96). TROPOMI showed better agreement with conventionally collocated Pandora measurements (0.73 < R2 < 0.76, 26–29% negative bias) than the other two satellite sensors (OMI and OMPS) attributed to its highest spatial resolution. The application of the wind-based collocation revealed that the TROPOMI showed a greater negative bias on the upwind side, which was less affected by anthropogenic emissions from the urban area, than the downwind side, and the increasing distance of the TROPOMI pixel from Pandora was the most critical factor deteriorating the intercomparison scores. The FRESCO-S TROPOMI cloud algorithm update to FRESCO-wide yielded a general increase in TROPOMI TCN, especially in the partially cloudy pixels, leaving only 11% (downwind) and 29% (upwind) negative bias from coincident Pandora measurements. Furthermore, the wind-based collocation method revealed the spatial distribution pattern of NOX (NO + NO2) emissions in the SMA, with significant emission sources in the northeastern and southeastern sides of the ground-based Pandora site in Seoul.

Determination of mixing layer height from co-located lidar, ceilometer and wind Doppler lidar measurements: Intercomparison and implications for PM2.5 simulations

Mixing layer height (MLH) is retrieved at an urban site in Seoul, Korea, from 2-year collocated remote sensing instrument measurements: elastic aerosol lidar, ceilometer, and wind Doppler lidar (WDL). All three measurements captured clear diurnal patterns of MLH development and break down, but large discrepancies were noted in the nocturnal MLH and the onset time of MLH development. Vertical wind speed standard deviation (σw) from WDL measurements displayed low MLHs during nighttime, compared to MLH retrieved from aerosol backscattering intensity profiles (mean bias = −0.21 km). To this extent, mixing represented by σw showed close correlation with surface heating but significant discrepancies with the vertical distribution of atmospheric constituents, especially at night. Comparison of MLH from elastic aerosol lidar and WDL with WRF-Chem simulation results showed that WRF-Chem MLH closely resembled MLH retrieved from WDL, indicating that WRF-Chem sufficiently simulated turbulence, but displayed lower nocturnal MLH compared to lidar-derived MLH. Furthermore, investigation of the vertical profiles of PM2.5 in the model displayed confined distribution of aerosols within the nocturnal MLH, leading to overestimation of surface PM2.5 concentration. For the case studies of May 12 and 18, 2016, implicating full mixing within the MLH defined by aerosol lidar measurements on WRF-Chem PM2.5 vertical distribution simulations was shown to significantly reduce WRF-Chem PM2.5 simulation errors from mean normalized bias of 52% to 19%.

수상레저스포츠 시설의 SNS 마케팅활동, 고객만족도 및 행동의도의 인과관계

The purpose of this study is to investigate the causal relationship between SNS marketing activities of water leisure sports facilities and consumer satisfaction and behavioral intention. To achieve the purpose of this study, after viewing and visiting the social media marketing activities of water leisure sports facilities, selecting water leisure sports participants as a population, a convenient sampling method using one facility in Gyeonggi-do and three windsurfing sites in Seoul. The survey was conducted from July to the end of August 2020. A total of 280 questionnaires were collected, but data from 269 questionnaires were used for actual analysis, excluding 11 questionnaires that were judged to be unfaithful. 24.0 and LISREL Ver. 8.52 A statistical analysis program was used to perform frequency analysis, reliability analysis, confirmation factor analysis, correlation analysis, and structural equation model analysis. The results obtained through the above analysis are as follows. First, it was found that social media marketing activities of water leisure sports facilities had a partially significant effect on customer satisfaction. Second, it was found that customer satisfaction with water leisure sports facilities had a significant effect on behavioral intention. Finally, it was found that playfulness among the social media marketing activities of water leisure sports facilities had an indirect effect on behavioral intention.

Framework for Long-Term Public Housing Supply Plan Focusing on Small-Scale Offsite Construction in Seoul

The public housing demand in Seoul has been continuously increasing, but the available land for housing is insufficient. To meet the demand, the Seoul government is planning to develop small-scale housing in urban areas through various methods. Construction activities for increasing housing capacity cause negative environmental impacts, and this inevitably leads to an increase in the number of civil complaints. The complaints can be mitigated by using offsite construction (OSC) for fabricating components. However, OSC remains underdeveloped in Korea owing to concerns over high project costs. To promote OSC, the government must develop a long-term plan to secure demand for OSC. For such a plan, the number and feasibility of applicable sites in Seoul must be estimated. This study suggests a two-stage research framework: (1) estimate the number of applicable sites in Seoul using GIS and (2) conduct feasibility analyses of these sites through architectural planning. The estimated number of sites was equal to the expected supply of small-scale housing units in Seoul for 8 years, and the selected case sites were identified to be feasible. Therefore, the use of OSC for developing small-scale housing units in Seoul is reasonable. This research differs from previous studies in that the previous use of qualitative studies to promote modular construction was replaced with a quantitative analysis that included the entire Seoul area. Using the research framework, the Seoul government can develop a specific long-term plan based on the quantitative research analysis. Furthermore, manufacturers can develop plans based on the government plan and deliver returns on the higher initial costs. The contractors can reduce the higher project cost and doing so is expected to mitigate the negative perception and to promote modular construction in Korea.

Planetary Boundary-Layer Structure at an Inland Urban Site under Sea Breeze Penetration

We evaluated the performance of the Weather Research and Forecasting Model in simulating the boundary-layer structure at an urban site in Seoul on two clear summer days against observations made using a ceilometer, a Doppler wind lidar, and a microwave radiometer. The planetary boundary-layer height (PBLH) was estimated from two different methods using observations: the ceilometer-based method (CBM) and bulk Richardson number method (BRM). The maximum PBLH was well captured by the model but PBLH was underestimated in the late afternoon and evening. To examine the cause for underestimation of PBLH in the evening, we compared the wind and virtual potential temperature structure between the simulation and observations. The model captured the timing of the sea breeze well, but it considerably overestimated the intensity of the simulated sea breeze, resulting in an overestimated cold advection by a sea breeze. The effect of the overestimated cold advection on evening PBLH was greater when the sea breeze arrived in the late afternoon and hence the vertical extent of the sea breeze was shallow. This study underscores the importance of accurately simulating the sea breeze for PBLH prediction in the evening, over the inland urban areas under sea breeze penetration.

Characterization of Seasonal Difference of HULIS-C Sources from Water Soluble PM2.5 in Seoul, Korea: Probing Secondary Processes

HUmic-LIke Substances (HULIS) consists of a significant fraction of water-soluble organic carbon (WSOC) and optically active brown carbon. Understanding seasonality in their abundance and sources is an important step to quantifying their impacts on air quality and climate. In this study, we characterized the seasonal variation of HULIS-C (the carbon component of HULIS) and identified primary and secondary sources contributing to HULIS-C at an urban site in Seoul, Korea by analyzing 131 PM2.5 samples collected over a year from October 2012 to September 2013. The HULIS-C in Seoul had an annual average of 2.0 µg m–3, and displayed a seasonality of highest abundance in the winter (2.7 ± 1.3 µg m–3) and the lowest in the summer (1.7 ± 0.8 µg m–3). Its fraction in WSOC reached up to 0.96 in the summer while remained relatively constant in the range of 0.4–0.6 in other seasons. Sources of HULIS-C were resolved using Positive Matrix Factorization (PMF) and checked using inter-species relationships between HILIS-C and aerosol components. Specifically, secondary processes including aging and heterogeneous reaction (26%) contributes to the year-round background concentration of HULIS-C and fresh biomass burning (38%) and incomplete combustion (16%) were the major sources of underlying seasonal variation. We also found aging process in the secondary process had an important role in HULIS-C formation and was a dominant contributor in the summer while heterogenous reaction contributed considerably in other seasons. It implies that the different secondary processes in forming HULIS should be considered when the radiative forcing of brown carbon is estimated. Because these processes can lead the different physicochemical properties of HULIS in aerosols.

Spatial-seasonal variations and source identification of volatile organic compounds using passive air samplers in the metropolitan city of Seoul, South Korea

The large emission of volatile organic compounds (VOCs) is an important environmental issue in Seoul, the capital of South Korea. However, the spatial distribution of VOC emissions has not yet been clearly revealed. In this study, passive air samplers (PASs) were seasonally deployed to measure 50 VOCs at 26 urban, 4 road, and 6 background sites in Seoul. Among the target compounds, toluene (summer: 8.72 μg/m3; winter: 5.47 μg/m3), ethyl acetate (summer: 2.36 μg/m3; winter: 3.51 μg/m3), and ethylbenzene (summer: 1.72 μg/m3; winter: 0.88 μg/m3) exhibited higher mean concentrations than other compounds. Printing offices and industrial facilities seem to have strong influences on the VOC levels in the center and southwest of Seoul, respectively. Diagnostic ratios indicated that the main sources of VOCs were related to local volatilization in summer and vehicular exhaust and transport from other areas in winter. Positive matrix factorization (PMF) suggested four major sources of VOCs: residential/commercial solvents for printing and painting (Factor 1); transport from other areas (Factor 2); industrial solvents for painting, manufacturing, and cleaning (Factor 3); and gasoline/diesel vehicular exhausts (Factor 4). Factors 1 and 3 were dominant in summer, and Factors 2 and 4 were dominant in winter. In conclusion, the seasonal meteorological conditions (e.g., temperature and wind patterns) were found to play an important role in the spatial distribution of VOCs in Seoul, and solvent use was a predominant source.

Preservation and Maintenance Trends of Historic Sites and the Present Condition of the Utilization of Historical and Cultural Resources : Focusing on historic sites in Seoul and Gyeonggi Province

Purpose: The readjustment of historic sites protected and preserved as cultural heritage zones is also directly related to the protection of individual property rights, and political intentions, values, and international trends cannot be ignored. It is hoped that it will be used as a basic data to prepare for the rapidly changing post-corona era by organizing the characteristics of types according to the current status of historical site use and organizing the preparation and improvement measures for the changing demand groups. Method: This study examined the current status of the utilization and preservation management of historic sites, focusing on data from 137 historic sites in Seoul and Gyeonggi Province. To this end, the government analyzed the actual state of public awareness of cultural assets through analysis of regular survey records and statistical indicators. In addition, it is intended to suggest measures to improve the development and utilization of historical site in the future by classifying the status of historical site use. Result: First, it is necessary to utilize realistic content that can provide new opportunities for experience in historical sites through various augmented reality experiences. Second, it is required to expand the number of cultural commentators and establish an integrated experience program for historic sites without specialized operating facilities. Third, the use of culture park of historic sites should be applied with a management method that minimizes human input by expanding environmental maintenance and convenience facilities considering the use of historic sites, and establishing remote management systems such as CCTV, disaster prevention, and crime prevention in cultural heritage zones.

Impact of the exclusive median bus lane system on air pollution concentrations in Seoul, Korea

Since many previous studies reported the health effect of air pollution and indicated traffic as a major pollution source, significant policy efforts have been made to control traffic to reduce air pollution. However, there have been few studies that evaluated such policy implementation. In Seoul, Korea, the exclusive median bus lane system was implemented in 2004, and the metropolitan government applied air pollution reduction policies such as conversion of diesel buses to compressed natural gas buses and installation of emission control devices. This paper aimed to investigate the impact of the exclusive median bus lane system on air pollution reduction. Using hourly concentrations of particulate matter (PM10) and nitrogen dioxide (NO2) measured at 131 regulatory monitoring sites in Seoul and Gyeonggi-do for 2001-2014, we calculated annual and daily average concentrations at each site. We assessed the impact of the policy using differences-in-differences analysis by annual and daily average models after adjusting for geographic and/or meteorological variables. This method divides population into treatment and control groups with and without policy application, and compares the difference between the two time periods before and after the policy implementation in the treatment group with the difference in the control group. We classified all monitoring sites into treatment and control groups using two definitions: 1) Seoul vs. Gyeonggi; 2) within vs. outside 300 meters from the median bus lane. Pre- and post-policy periods were defined as 2001-2005 and 2006-2014, and 2004 and 2014 in the annual and daily models, respectively. The decrease in PM10 concentrations between the two periods across monitoring sites in the treatment group was larger by 1.73-5.88 μg/m3 than in the control group. NO2 also showed the decrease without statistical significance. Our findings suggest that an efficient public transport policy combined with pollution abatement policies can contribute to reduction in air pollution.

Comparison of Aerosol Properties in the Korean Peninsula Between AERONET Version 2 and 3 Data Set

To investigate the consistency and difference between AERONET version 2 and 3 data set in the Korean peninsula, we compared several aerosol optical properties for 12 Korean AERONET sites having at least 2-year measurement records. Generally, both version products have similar patterns, but we sometimes found a little regional difference. While the aerosol optical depth (AOD) is analogous between version 2 and 3, the version difference of single scattering albedo (SSA) is the largest. Angstrom exponent (AE) and fine mode fraction (FMF) values are sometimes different in maritime conditions. Two AERONET sites in Seoul (Seoul_SNU and Yonsei_Univ) have some differences between version 2 and 3, probably related to the higher sensitivity of version 3 data to the fine mode particle. Since parameters revealing the aerosol radiative property (e.g., SSA) and size information (e.g., AE and FMF) show some version differences regionally, we compared the result of aerosol type classification using these parameters. As a result, we found that the version difference of aerosol size and radiative property can induce the different diagnosis of locally dominant aerosol types. In spite of these findings, consistency between version 2 and 3 is quite large. Thus, regional patterns of aerosol optical properties previously found based on AERONET version 2 look still valid in the Korean peninsula.

Time Series Analysis on Urban Development and Taxi Accommodation Garage Sites in Seoul

Time Series Analysis on Urban Development and Taxi Accommodation Garage Sites in Seoul