• Journal of the Korean Society of Safety
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• v.37 no.1
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• pp.64-69
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• 2022

The study measured a subway construction worker's Macpa stress by Heart Rate Variability measuring instrument and conducted a survey of Korean job stress from subway construction workers. Also, the study analyzed the relationship between Macpa stress index and Korean job stress result and suggested managing stress method for each item. According to National Statistical Office data, the first line subway in Seoul was started to open in 1974. The extended total length is 996 kilometers until 2019. Many aged workers are currently working at subway construction sites due to the avoidance of young workers since the past until now. It means that the elderly has a substantial portion among subway construction workers. The productivity has been adversely affected by health problems due to the aging of workers, job stress due to heavy work, and personal health problems. So, the regulation and policies on job stress health management are being strengthened. The data were measured Macpa stress by machine measuring heart rate variability and conducted Korean job stress survey(shortened) from Sa-sang to Ha-dan line Busan subway construction workers for analyzing the relationship. Independent variable were age, job duration, job position, employment type, working type in this study. Macpa's dependent variable was stress index and Korean job stress survey(shortened)'s dependent variables were job requirements, job autonomy, relationship conflict, job instability, organizational structure, inappropriate compensation, working place culture, and total score. SPSS 12.0 K Statistics Program was used for statistical analysis. Kruskal-wallis test, a nonparametric statistical analysis, was used because the data are difficult to be assumed as normal distribution. As a result, the paper indicated the significant correlation between Macpa stress index and Korean job stress(short version). The elderly workers presented higher Macpa index and higher job stress due to aging and heavy-duty work. The majority workers were daily workers who had unstable working condition and uncertainty about the future. The study suggested a manual that could reduce job stress for subway construction workers and future study deriving management tool through analyzing job stress factor is necessary.

• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.50-54
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• 2006

A fire in a subway station platform, completely isolated by screen doors, was numerically simulated to investigate problems in smoke control and find their countermeasures. A part of the platform, $40m{\times}5m$ floor and 3 m high, and a fire of 1 MW were considered, and the smoke extraction system was assumed to start operation at the onset of the fire. For three different values of the exhaust air flow rate, 0.1, 2, and $4m^3/min-m^2$, the distributions of temperature, concentrations of soot and carbon monoxide, and those of visibility were compared. The time-variations of the number of randomly distributed particles in the space were also investigated for the air flow rates to see the efficiency in smoke control. It was shown that smoke control takes time by lack of air supply. It was also confirmed that air supply from the railway to the platform at emergency is needed so that smoke is able to be controlled efficiently, and that opening the doors at the both ends of the platform is desirable until the fire is completely extinguished.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.6 s.58
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• pp.192-203
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• 2009

In the new Seoul-Busan high speed railroad construction specially in area of city center passage the roadbed establishment is recommended the staibility for the existing subway tunnel segments of Busan subway 1st and 2nd lines regarding the appearance condition, a quality condition and the durability of the objective facility, and it evaluates the numerical analysis using MIDAS/GTS which leads the stability of the objective facility and investigatesd tunnels. Fundamental issues in tunneling under high groundwater table are discussed and the effect of groundwater on tunnel excavation was examined using a 3D stress-pore pressure coupled Finite-Element Method. Based on the results the interaction mechanism between the tunnelling and groundwater is identified. In the both of 1st and 2nd Line the maximum sinkage, unequal sinkage and the lining stress from numerical analysis are within permission and the damage degree is appearing to be disregarded. But it enforces necessary Pre-grouting in order to minimize an actual tunnel face conduct and when the tunnel is excavated it is also necessary to minimize the outflow possibility.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.2_1
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• pp.217-223
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• 2023

With the rapid advancement of technologies, need for different research fields where this technology can be used is also increasing. One of the most researched topic in computer vision is object detection, which has widely been implemented in various fields which include healthcare, video surveillance and education. The main goal of object detection is to identify and categorize all the objects in a target environment. Specifically, methods of object detection consist of a variety of significant techniq ues, such as image processing and patterns recognition. Anomaly detection is a part of object detection, anomalies can be found various scenarios for example crowded places such as subway stations. An abnormal event can be assumed as a variation from the conventional scene. Since the abnormal event does not occur frequently, the distribution of normal and abnormal events is thoroughly imbalanced. In terms of public safety, abnormal events should be avoided and therefore immediate action need to be taken. When abnormal events occur in certain places, real time detection is required to prevent and protect the safety of the people. To solve the above problems, we propose a modified YOLOv5 object detection algorithm by implementing dilated convolutional layers which achieved 97% mAP50 compared to other five different models of YOLOv5. In addition to this, we also created a simple mobile application to avail the abnormal event detection on mobile phones.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.745-752
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• 2011

Light Rail Vehicle(LRT) is "New Transit System" that has transportation capacity as well as physical size of vehicle is in-between bus and subway. The demand of LRT system is increasing rapidly; both domestically and internationally. Reason being is that it is more economical and eco-friendly compare to existing heavy rail vehicle. Especially, Busan Subway Line 4 K-AGT (Rubber-tired LRT) being the first of its kind to start revenue service in Korea, it is very much likely that application of its demand will continue to increase. Considering its trend, study to reduce implementation cost of LRT is being pursued in many different aspects; reducing construction cost is one that aspect. In this study, on-site application of 'Up-Down Turnout System' implementation research has been carried out which can replace existing 'Left-Right Turnout System'. When safety of its type gets verified, application of this system to line which intends to use K-AGT, Shin-Lim Line and Dong-Book Line, expects to save its construction cost. This thesis paper reports ongoing research of AGT 'Up-Down Turnout System' development and main component design factors, fundamental principle, performance test result.

• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.79-92
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• 2006

Environmental capacity assessment of Busan city was conducted to provide basis for planning on sustainable development and growth of the city. Using Onish model, assessment was carried out on amenities and service facilities for the citizens of Busan city. Ecological Footprint model was used to judge if the city exceeds the its environmental capacity and to estimate the extent of the excess if it exists. The analysis using Onish model revealed that the citizens of Busan city are generally well supported by the infrastructure and service facilities of the city. Water treatment and supply facilities have enough capabilities to support the city, whereas the relatively low rate of sanitary sewer supply (78%) suggests the need for further improvement in the wastewater area. The capacities of sanitary landfills are found sufficient enough to support the city for the next 10 years. The high value for the line length served per capita in the subway sector hints on certain inconvenience of commuters. All the air quality indicators meet the Korean and WHO standards except for $NO_2$. The ecological footprint model analysis produced EF indicators for Busan city of 3.04 ha/person and 2.54 ha/person for the years of 1993 and 2003, respectively. The decrease of the indicator from 1993 to 2003 is mainly due to the incorporation of Gijang area by Busan city in 1995, suggesting the importance of the ecologically productive area in the evaluation using this model. The analysis on the ecological deficit that is based on ecologically productive land shows that the consumption by Busan city exceeds its ecologically available production by 19,600% as of 2003. The area needed to support the consumption of Busan city in 2003 is 123 times as large as the present area of Busan city, which is substantially lower than the multiplier (742) obtained for Seoul city in 1997 but is higher than those observed for Chongju city (71 in 1999) and Ulsan city (39 in 2001).

• Journal of Korean Society of Transportation
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• v.34 no.4
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• pp.330-340
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• 2016

The main objective of study was to analyze the effectiveness of transit mall. To this end, this study compared operational status of transit malls in operation (Daegu, Seoul and Busan). For the city of Busan where the latest transit mall became operational in 2015, a discriminant model was proposed to determine user satisfaction/dissatisfaction. The outcomes of comparative study showed that each city has different operational focus - Seoul has focus on traffic demand management, Busan has focus on walking environment, and Daegu has focus on accessibility to public transportation. Also, the discriminant model indicated that market sentiment, convenience of bus service, traffic accident risk, number of pedestrian, market user number have effects on user satisfaction. These results implied that, to improve user satisfaction, measures for market revitalization such as opening events and forming consultative groups need to be prepared and traffic conditions should also be improved through expansion of curfew time, linkage with subway station.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.2
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• pp.3-9
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• 2009

These days, the value of the limited land rises in the city according to the increase of the population and the industrial development. And various studies on estimating the land price have been accomplished for the purpose of using the land efficiently. As a result, the officially assessed land price system was arranged. However the system is insufficient to reflect realities. Therefore, in this study, we examined the spatial distribution of the land price by joining spatially the officially assessed land price of Haeundae-gu, Busan from 2004 to 2008 to the map of lot number. We also computed and compared the change rate of the land price for 5 years. And we analyzed the relation between factors including the distance from the subway station, the land use and the land category which have an effect on the officially assessed land price and it using GIS technology.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.541-552
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• 2010

The light rail transit (LRT) having bus lines as subsystem is being constructed or planned in the suburban area of metropolitans and medium size cities. However, there is difficulty in establishing the service coverage (SC) of the LRT because the LRT is a completely new transit mode in Korea. The purpose of this study is to provide the basic data and techniques to be used for establishing the SC of the future LRT by understanding the SC characteristics of buses and subways and building models to estimate the walking distances of their users. Busan City is selected as the study city and the SC's of buses and subways are surveyed simultaneously. A total of 9 variables for 82 stations are collected and the cluster analysis is conducted about the variables. The station areas are divided to three types of CBD (Central Business District), sub-CBD and regional center based on the analysis. A station in each area is selected as the study station. At the walking distance (WD) analysis for each mode, the 80 percentile WD of the subway is 672 m and that of the bus is 472 m. In comparing the SC's of both modes by the type of station areas, there are not significant differences between the SC's of sub-CBD and regional center except CBD. At analysis of the relationship between the personal attributes and the WD, for subway users the WD of female is longer than that of male and apartment residents use subway more positively than single house residents do. For the models to estimate the walking distances, the simple regression models were built employing the income as independent variable by dividing the stations into CBD abd non-CBD stations.

• Corrosion Science and Technology
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• v.6 no.6
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• pp.308-310
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• 2007

The owner of underground metallic structures (gas pipeline, oil pipeline, water pipeline, etc) has a burden of responsibility for the corrosion protection in order to prevent big accidents like gas explosion, soil pollution, leakage and so on. So far, Cathodic Protection(CP) technology have been implemented for protection of underground systems. The stray current from DC subway system in Korea has affected the cathodic protection (CP) design of the buried pipelines adjacent to the railroads. In this aspect, KERI has developed a various mitigation method, drainage system through steel bar under the rail, a stray current gathering mesh system, insulation method between yard and main line, distributed ICCP(Impressed Current Cathodic System), High speed response rectifier, restrictive drainage system, Boding ICCP system. We installed the mitigation system at the real field and test of its efficiency in Busan and Seoul, Korea. In this paper, the results of field test, especially, distributed ICCP are described.