Seoul Station Research Articles

Spatial modeling for radon concentrations in subway stations in Seoul, Korea.

This study examined the environmental and geological determinants of radon concentration in subway stations by applying a spatial statistical model to the integrated GIS database. The data were collected for 237 underground subway stations located inside the city of Seoul, South Korea and used for mapping to illustrate the spatial distribution of airborne radon exposure and analysis of potential contribution of station-specific and geological determinants. A Bayesian conditional autoregressive regression (CAR) model was developed to explain the radon concentrations, and the predicted radon surface was generated and visualized to identify hotspot regions where elevated radon exposure is likely to be present in underground settings. The findings include: (1) subway stations located within granite bedrock maintained relatively higher radon concentrations; (2) underground radon emanation is not only controlled by lithology and the associated uranium content of the rocks and soil, but also by structural factors which facilitate easy migration of radon from deeper parts of the earth's crust; (3) radon risks would be elevated if the underground facility is constructed too deep without any control measure; and (4) not only the foundation of an underground facility but also the nature of the soil and rocks in the vicinity helps determine whether or not dangerous levels of radon gas are likely to accumulate inside. This modeling effort is expected to provide guidelines regarding the identification of future station locations with a lower radon risk and the mandatory installation of adequate radon reduction systems for the underground space where people stay or commute for long periods of time.

The New Zombie Apocalypse and Social Crisis in South Korean Cinema (translation into Russian)

The popular culture version of the zombie, developed over the latter half of the twentieth century, made only sporadic appearances in South Korean film, which may in part be attributed to the restrictions on the distribution of American and Japanese films before 1988. Thus the first zombie film Monstrous Corpse (Goeshi 1980, directed by Gang Beom-Gu), was a loose remake of the Spanish-Italian Non si deve profanare il sonno dei morti (1974). Monstrous Corpse was largely forgotten until given a screening by KBS in 2011. Zombies don’t appear again for a quarter of a century. This article examines four zombie films released between 2012 and 2018: “Ambulance”, the fourth film in Horror Stories (2012), a popular horror portmanteau film; Train to Busan (2016) (directed by Yeon Sang-Ho), the first South Korean blockbuster film in the “zombie apocalypse” sub-genre; Seoul Station (2016), an animation prequel to Train to Busan (also directed by Yeon Sang-Ho); and Rampant (2018, directed by Kim Seong-Hun ), a costume drama set in Korea’s Joseon era. Based on a cognitive studies approach, this article examines two conceptual metaphors which underlie these films: the very common metaphor, LIFE IS A JOURNEY, and the endemically Korean metaphor THE NATION IS A FAMILY.

Air Pollutant Concentration Prediction Based on a CEEMDAN-FE-BiLSTM Model

The concentration series of PM2.5 (particulate matter ≤ 2.5 μm) is nonlinear, nonstationary, and noisy, making it difficult to predict accurately. This paper presents a new PM2.5 concentration prediction method based on a hybrid model of complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and bi-directional long short-term memory (BiLSTM). The new method was applied to predict the same kind of particulate pollutant PM10 and heterogeneous gas pollutant O3, proving that the prediction method has strong generalization ability. First, CEEMDAN was used to decompose PM2.5 concentrations at different frequencies. Then, the fuzzy entropy (FE) value of each decomposed wave was calculated, and the near waves were combined by K-means clustering to generate the input sequence. Finally, the combined sequences were put into the BiLSTM model with multiple hidden layers for training. We predicted the PM2.5 concentrations of Seoul Station 116 by the hour, with values of the root mean square error (RMSE), the mean absolute error (MAE), and the symmetric mean absolute percentage error (SMAPE) as low as 2.74, 1.90, and 13.59%, respectively, and an R2 value as high as 96.34%. The “CEEMDAN-FE” decomposition-merging technology proposed in this paper can effectively reduce the instability and high volatility of the original data, overcome data noise, and significantly improve the model’s performance in predicting the real-time concentrations of PM2.5.

An Analysis on the Effect of Rent-seeking Behavior for Public Goods on Housing Prices: focusing on the case of changing the name of Jamsilsaenae station in Seoul

An Analysis on the Effect of Rent-seeking Behavior for Public Goods on Housing Prices: focusing on the case of changing the name of Jamsilsaenae station in Seoul

Effects of land use on time-of-day transit ridership patterns

This study aimed to evaluate how built environments, especially land use, affect time-of-day transit demands, using data collected from neighborhoods around subway stations in Seoul, South Korea. The stations were first clustered by their boarding and alighting ridership sequences across times. The outcomes showed that the geographical distribution of clustered stations coincides with land use divisions. For each cluster, we estimated latent growth curve models to examine how land use determines time-of-day ridership patterns. The modeling outcomes showed that the same land use pattern and intensity differently affect ridership volumes across times and locations. The findings in this study indicated that uniform land use in areas is a dominant factor for asymmetric ridership patterns—passengers are inevitably concentrated in peak hours if a certain land use is predominant—and these asymmetric ridership patterns can be mitigated when neighborhood commercial land use is included in the areas.

Leveraging temporal changes of spatial accessibility measurements for better policy implications: a case study of electric vehicle (EV) charging stations in Seoul, South Korea

ABSTRACT The implementation of temporal dynamic variables improves the accuracy of spatial accessibility measurements. However, in previous studies, the temporal dynamics were partially incorporated, and a few snapshots were subjectively selected to demonstrate temporal changes of spatial accessibility, which may not represent the entire variation. In this study, we proposed a conceptual framework to leverage spatial accessibility temporal fluctuation, facilitating decision-making. Not only was the full implementation of time-dependent inputs, but the framework also employed the Gaussian two-step floating catchment area (G2SFCA) method and measured hourly spatial accessibility over 24 hours. Then, a temporal clustering with K-means and hierarchical clustering methods was performed, detecting a few distinctive temporal changes. Lastly, the significance of dynamic accessibility measurement and temporal clustering was validated using Pearson’s correlations. We took electric vehicle (EV) charging stations in Seoul, South Korea, as a case study. The results presented that neglecting temporal dynamics could fail to predict accessibility during the daytime. Additionally, temporal clustering summarized the 24-hour changes of accessibility into five temporal phases and showed the need for additional resources for insufficient accessibility locations in the afternoon. Consequently, our framework elicited the temporal changes of accessibility measures and identified a specific space and time for supplementary infrastructure.

Reassessing the frequency and severity of meteorological drought considering non-stationarity and copula-based bivariate probability

Drought is a multifaceted natural phenomenon with diverse spatial and temporal characteristics and significant environmental, social, and economic effects. The utility of conventional drought indices based on the assumption of stationarity is questionable due to the advent of rapid environmental change. We proposed a non-stationary standardized precipitation index (SPINS) to reassess the nature of meteorological drought. Precipitation observations from eight rain gauge stations for 1961–2017 in South Korea were fitted to a non-stationary gamma distribution using a generalized additive model in location, scale, and shape algorithm. Drought duration and severity were identified by SPINS and joint and conditional return periods were estimated using copula-based bivariate probabilities. The results show that average drought duration, severity, and frequency obtained from SPINS were more severe than those produced by a conventional standardized precipitation index (SPIC). The average inter-arrival time was 41.46 months and 39.86 months for SPIC and SPINS, respectively, at the Seoul station. The joint return periods of observed drought event from March 2008 to June 2008 with a duration of 4 months and a severity of 4.8 were 10.4 and 6.4 years for the SPIC and SPINS, respectively, at the Seoul station. We conclude that return periods calculated using the SPINS are more reliable than those calculated by the SPIC. These findings should prove helpful in drought management and risk assessment under a changing environment as effective management requires prior knowledge of events.

Determinants of Behavioral Intention of the Use of Self-Order Kiosks in Fast-Food Restaurants: Focus on the Moderating Effect of Difference Age

The aim of this study was to derive determinants that affect the behavior associated with using self-order kiosks among fast-food restaurant consumers through the Unified Theory of Acceptance and Use of Technology model, and to analyze the moderating effect of consumers’ difference age (difference between individuals’ cognitive age and chronological age) among the variables. From December 1 to 30, 2019, a survey was conducted on 316 customers using four different fast-food restaurants in the Seoul Station. The results showed that the higher the price value, social influence, performance expectancy, and hedonic motivation, the higher the behavioral intention of ordering through the kiosk; furthermore, the higher the difference age, the higher the behavioral intention of using a kiosk. Therefore, fast-food restaurant operators need to ensure that customers who are unfamiliar with using kiosks can order and make payments through kiosks with minimal effort and reasonable price value.

Analysis on the Efficiency Change in Electric Vehicle Charging Stations Using Multi-Period Data Envelopment Analysis

It is highly challenging to measure the efficiency of electric vehicle charging stations (EVCSs) because factors affecting operational characteristics of EVCSs are time-varying in practice. For the efficiency measurement, environmental factors around the EVCSs can be considered because such factors affect charging behaviors of electric vehicle drivers, resulting in variations of accessibility and attractiveness for the EVCSs. Considering dynamics of the factors, this paper examines the technical efficiency of 622 electric vehicle charging stations in Seoul using data envelopment analysis (DEA). The DEA is formulated as a multi-period output-oriented constant return to scale model. Five inputs including floating population, number of nearby EVCSs, average distance of nearby EVCSs, traffic volume and traffic congestion are considered and the charging frequency of EVCSs is used as the output. The result of efficiency measurement shows that not many EVCSs has most of charging demand at certain periods of time, while the others are facing with anemic charging demand. Tobit regression analyses show that the traffic congestion negatively affects the efficiency of EVCSs, while the traffic volume and the number of nearby EVCSs are positive factors improving the efficiency around EVCSs. We draw some notable characteristics of efficient EVCSs by comparing means of the inputs related to the groups classified by K-means clustering algorithm. This analysis presents that efficient EVCSs can be generally characterized with the high number of nearby EVCSs and low level of the traffic congestion.

Broken Blueprints of Urban Space Reconstruction in the Seoul Station Area: Initiative to Deconstruct Border of 1968 Development Plans

20세기 초 서울역 일대는 철도를 중심으로 식민지배 권력의 공간분할 전략에 ‘부합’할수 있는 도시 동-서 간 경계의 도시공간으로 생산되었다. 그러나 1960년대 후반 하이 모더니즘에 기반을 둔 새로운 지배권력에게 이전 시기로부터 계승된 재래적 건조환경은 포화상태에 이른 도심 확장의 장애물로 문제시되었다. 이에 일대의 도시공간에 개입함으로써경계 문제를 극복하고자 했던 일련의 청사진들이 제시되었다. 본 논문은 그중 도시공간의전면적·급진적 재구조화를 통해 경계의 물질성을 해체하려는 내용을 포함했던 개발안들의 조감도(‘서울역주변 근대화계획 조감도’, ‘서울역복개공사 조감도’)를 중심사례로 살피며 당대 개발구상의 조건과 내용, 그리고 백지화의 원인을 맥락적으로 탐색한다. 또한 구상의 의도 및 내재적 한계를 분석한다. 이를 통해 본 논문은 현재적 현안으로 재부상한 서울역 일대 경계 극복의 전략에 일정한 시사점을 제언한다. 이전 시기의 개발구상에 내재되어 있던 권위주의적 성격과 자동차 모빌리티 편중성을 극복하는 비판적 전제 위에서, 서울역 일대 등 역세권과 구도심의 경계 문제의 해결을 위한 수단의 하나로 도시공간의 전면적·급진적 재구성을 논의·검토할 필요가 있다.

Analysis of Daily Load Patterns Taking into Consideration PEVs Charging Stations in Seoul, South Korea

This paper presents a methodology to calculate daily charging load curves in Seoul, South Korea, by taking into account plug-in electric vehicles (PEVs) charging stations, allowing Seoul’s government to determine the PEVs charging effect on the load. In particular, the study calculates the charging power of uncontrolled PEVs charging in terms of the daily operating characteristics of a vehicle traveling between home and workplace, with respect to PEVs charging stations in the city, according to the PEVs’ market share. For the controlled PEVs charging strategy based on morning and afternoon work-to-home and vice versa traffic characteristics and time-of-use (TOU) prices in Seoul, the study calculates daily load patterns of uncontrolled and controlled charging scenarios. After adding the calculated values to the existing load, the study assesses and compares their effects on the power grid. The results are as follows. If by 2030 the share of electric vehicles is 10%, compared to the existing load, the total load increases by about 13% between 9:00 and 11:00 in the morning for the uncontrolled mode and by about 10% for the controlled mode. The total load increases by about 16% between 20:00 and 22:00 for the uncontrolled mode and 17% for the controlled mode. However, if by 2040 the share of electric vehicles is 30%, compared to the existing load, the total load increases by about 35% between 9:00 and 11:00 in the morning for the uncontrolled mode and by about 32% for the controlled mode. Between 20:00 and 22:00, the uncontrolled mode’s total charging load increases by about 35% and the controlled mode’s total load by about 32%. The analysis also demonstrated that it was possible to achieve a significant load-leveling effect in all charging periods for the controlled mode, with the daily load pattern’s average leveling rate increasing by 8% and 13% in 2030 and 2040, respectively, based on the TOU price system compared with the uncontrolled mode. Based on these results, it is possible to determine the PEVs’ hourly charging load effect on the power grid in Seoul and establish a PEVs charging load management plan to prevent the power grid reinforcement and expansion and to satisfy its overload constraint by using an appropriate TOU price plan.

Physical Activity and Successful Pregnancy in 6 Months: A Finding from the Pregnancy and Urban Environment Study

Purpose: This study aimed to assess the association between physical activity and pregnancy in 6 months among infertile women who underwent in vitro fertilization (IVF).Methods: The participants included in this study were infertile women who underwent IVF at Cha Fertility Center in Seoul Station from October 2019 to February 2020. Of 132 women who agreed to participate in the study, one was eliminated for omitting the exercise questionnaire. A survey assessing the level of physical activity of infertile women was conducted using the Korean version of the International Physical Activity Questionnaires. We calculated metabolic equivalent task-minutes (MET-min) scores and obtained their IVF results after 6 months of the survey. Participants with less than 3,000 MET-min were classified into the minimally active group, and those with ≥3,000 MET-min were classified as the healthenhancing group. The 2 groups were compared based on age, anti-Müllerian hormone levels, body mass index, infertility duration, nulliparity, harmful alcohol drinking, history of smoking, obesity, male factors, and pregnancy rates. Adjusted relative risk for pregnancy was calculated using log-binomial regression analysis.Results: There was no significant difference in basal characteristics between the less active and health-enhancing groups. When controlling for all covariates, the relative risk for pregnancy was close to null with health-enhancing activity. The adjusted pregnancy rate decreased with increasing MET-min in the generalized additive model.Conclusion: We observed no positive association between physical activity and pregnancy rate among interfile women undergoing IVF. To confirm our findings, subsequent interventional studies would be needed.

Development of pan coefficient model for estimating evaporation: focused on Seoul station

Development of pan coefficient model for estimating evaporation: focused on Seoul station

Source Quantification of PM10 and PM2.5 Using Iron Tracer Mass Balance in a Seoul Subway Station, South Korea

In this study, we simultaneously measured the PM10 and PM2.5 mass concentrations and their heavy metal content for three days at a subway station in Seoul to investigate the airborne PM flows. The average concentrations were 59 µg m–3, 37 µg m–3, 111 µg m–3, and 369 µg m–3 for the PM10 and 43 µg m–3, 28 µg m–3, 58 µg m–3, and 132 µg m–3 for the PM2.5 at the outdoor air inlet, in the concourse, on the platform, and in the tunnel, respectively. We also found strong correlations between the temporal variations at adjacent sampling locations for both fractions, although they were higher for the PM2.5. Additionally, of the airborne trace metals detected at the sampling locations inside the station (the concourse, platform, and tunnel), iron (Fe) displayed the highest concentration and was thus selected as a tracer of PM. Applying a simple mass balance model to the Fe concentrations and ventilation rates revealed that 78% of the PM10 and 62% of the PM2.5 on the platform emanated from the tunnel, whereas 84% of the PM10 and 87% of the PM2.5 in the concourse originated outdoors (and arrived in the filtered air). These results further confirm that reducing PM emission from the tunnel is the most effective strategy for improving air quality on the platform and achieving compliance with the national guideline.

에너지 미터링 장치를 활용한 교류 전동차 소비전력량 분석

In this paper, we describe to evaluate the stability and reliability of the development of an electric multiple unit power measurement system. The power consumption was measured according to the driving mode of the train using the power measurement system between Incheon International Airport Station and Seoul Station. The average speed is 59.5[km/h] for manual operation and 59.7[km/h] for automatic operation during Incheon international airport to Seoul station, manual operation saves 35.8[kWh] energy compared to automatic operation. In addition, when converted into fuel economy according to the driving distance compared to the amount of power consumed, manual driving is about 0.11[km / kWh] and automatic driving is about 0.10[km / kWh], and the fuel economy of manual driving is analyzed to be 0.01[km / kWh] higher. From these results, it is possible to analyze the operating energy consumption of railway vehicles, and expected to increase the usability to improve vehicle operation energy efficiency.

지하철건설이 부동산시장에 미친 효과 분석 - 신분당선 건설이 양재역 주변의 토지 및 주택가격 변동을 중심으로 -

he data used in this study are the regional analysis results of the monthly land price change rate of the Bundang Line passing area from 1989 to 2014 provided by the Korea Appraisal Association, and the average individual publicly announced land price per ㎡ per year. In addition, the spatial scope of the study was limited to the station area around Gangnam-gu and Yangjae Station in Seoul. The results are summarized as follows. First, in the development of the subway line on the Sinbundang line, the rise in land price was different depending on the separation distance from the subway line. Second, the parallax ripple effect of subway development on land prices occurred chronologically according to the process of the subway development project. When comparing the rate of change in the average standard land price per square meter of Yangjae-dong at the time the subway development plan was announced (2002) and one year passed (2003), the annual increase rate was 20%. In view of this, it is true that the construction of the subway concentrates a large population and raises the land price of the surrounding area considerably. Of course, these population concentration phenomena can be said to be the result of expecting the convenience of a bridge.

Determinants of transit-oriented development efficiency focusing on an integrated subway, bus and shared-bicycle system: Application of Simar-Wilson's two-stage approach

This research explores the efficiency of Transit-Oriented Development (TOD) at transit stations in Seoul using a two-stage bootstrap Data Envelopment Analysis with truncated regression. The ridership, in terms of the bus, subway, and shared bicycle usage within the transit stations' impact area, is judged as an immediate output of TOD performance, and indicators relating to the core concepts of TOD are selected as inputs. In the first-phase, TOD efficiency estimates are computed and regressed on environmental variables in the subsequent phase to identify contributory factors of TOD efficiency. Assessing the performance of TOD at the transit station revealed that the stations located around the CBD where commercial activities highly concentrated and transit stations are connected were more efficient compared to those located at the periphery of the city. The second-stage results indicate that a rise in pedestrian volume, the number of shared-bicycle stations and bus stops, commercial floor area, and traffic congestion around a transit station improves the efficiency of TOD. Our study makes a significant contribution to the literature by employing a more robust approach to explore TOD efficiency at transit stations. The findings of this study provide useful implications and insights for urban planners and policymakers across cities.

Developing a Reliability Index of Low Impact Development for Urban Areas

A defining characteristic of the urbanization is the transformation of existing pervious areas into impervious areas during development. This leads to numerous hydrologic and environmental problems such as an increase in surface runoff due to excess rainfall, flooding, the deterioration of water quality, and an increase in nonpoint source pollution. Several studies propose supplementary measures on environmental change problems in development areas using the low impact development technique. This study investigated the reduction of nonpoint source pollutant loads and flooding in catchments through urban catchment rainfall–runoff management. For the quantitative assessment of flood disasters and water pollution problems, we propose a reliability evaluation technique. This technique refers to a series of analysis methods that determine the disaster prevention performance of the existing systems. As the two factors involve physical quantities of different dimensions, a reliability evaluation technique was developed using the distance measure method. Using the storm water management model, multiple scenarios based on synthetic rainfall in the catchment of the Daerim 2 rainwater pumping station in Seoul, South Korea, were examined. Our results indicate the need for efficient management of natural disaster risks that may occur in urban catchments. Moreover, this study can be used as a primary reference for setting a significant reduction target and facilitating accurate decision making concerning urban drainage system management.

Spatial and temporal characteristics of tropical nights in Seoul.

We examined the spatial and temporal characteristics of tropical nights (TNs) in Seoul to determine whether land use factors increase the frequency of TN. The number of TN was derived using data from 23 Automatic Weathering Stations (AWS) in Seoul for 1998-2006, and 26 AWS in Seoul and nine Gangnam-gu stations for 2007-2013. The results show that the number of TN recorded in the Seoul Automatic Synoptic Observation System (ASOS) gradually increased from 1971 to 2013. TN occurred most frequently in early August, followed by mid-August, late July, late August, mid-July, early July, early September, and mid-September. The largest annual average difference occurred between Gangnam Station and Yeomgokdong, in spite of the short physical distance (4.5 km) between two stations at Gangnam-gu. There were more TNs at high-rise buildings and commercial business district (CBD) areas with low sky view factors (SVF) than in mountain foothill areas.

Valuation of Metro Crowding Considering Heterogeneity of Route Choice Behaviors

More than seven million people rely on the metro system daily in Seoul, South Korea. The metro system plays a vital role in connecting passengers to desired locations with the advantage of allowing for travel reliability and relative safety, all the while being an environmentally friendly alternative to other transport systems. Despite the benefits mentioned above, crowding on the metro can contribute significantly to deterioration of the individual’s travel experience and necessitates its proper evaluation, so that user experience may be improved. To achieve this, this study quantifies the level of crowding by deriving estimates for route choice models with crowding as one of the main attributes for metro passenger decisions. The data used in the model are obtained through a stated preference survey, which was conducted at five major transfer stations in Seoul to estimate factors such as travel time, transfers, travel cost, and crowding level. These attributes are then analyzed using homogeneity and heterogeneity models of different trip purposes. Furthermore, crowding multipliers (CMs) for Seoul are estimated and compared with those of other cities around the world. Estimation results pinpoint crowding as one of the main factors in route choice for passengers for all types of trips, with multiplier values reaching the highest of all cities around the world for sitting CM and standing CM at 2.15 and 3.22, respectively. Our results indicate that Seoul metro passengers are more sensitive to crowding than any of the passengers analyzed in 18 major city metros around the world.