• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.234-242
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• 2016

In express operation plans for urban trains, it is effective for the reduction of the number of sidetracks to apply a high performance train that has improved acceleration/deceleration ability and a regular train to local and express trains, respectively. In this research, based on a plan to use a high performance train for a local train, an optimization methodology is suggested to reduce the number of sidetracks and the operation time of the local train simultaneously. The optimization solver applied in this research is a genetic algorithm; headway, location of sidetrack and waiting time at the sidetrack are considered as design variables in the optimization problem. Consequently, by applying this system to Seoul metro line no.7, the effect of the suggested methodology was verified by obtaining the proper optimum solution.

• Geomechanics and Engineering
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• v.16 no.6
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• pp.643-654
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• 2018

Tunnel excavation leads to a disturbance on the initial stress balance of surrounding soils, which causes convergences around the tunnel and settlements at the ground surface. Considering the effective impact of settlements on the structures at the surface, it is necessary to estimate them, especially in urban areas. In the present study, ground settlements due to the excavation of East-West Line 7 of the Tehran Metro (EWL7) and the Abuzar tunnels are evaluated and the effect of the lateral earth pressure coefficient ($K_0$) on their extension is investigated. The excavation of the tunnels was performed by TBMs (Tunnel Boring Machines). The coefficient of lateral earth pressure ($K_0$) is one of the most important geotechnical parameters for tunnel design and is greatly influenced by the geological characteristics of the surrounding soil mass along the tunnel route. The real (in-situ) settlements of the ground surface were measured experimentally using leveling methods along the studied tunnels and the results were compared with evaluated settlements obtained from both semi-empirical and numerical methods (using the finite difference software FLAC3D). The comparisons permitted to show that the adopted numerical models can effectively be used to predict settlements induced by a tunnel excavation. Then a numerical parametric study was conducted to show the influence of the $K_0$ values on the ground settlements. Numerical investigations also showed that the shapes of settlement trough of the studied tunnels, in a transverse section, are not similar because of their different diameters and depths of the tunnels.

• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.609-615
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• 2012

TPS (Train Performance Simulation) based on ATO (Automatic Train Operation) is required for driverless LRT (Light Rail Transit) operation plan instead of typical TPS based on driver operation. In this paper, new TPS model using ATO pattern is proposed and compared with the automatic train operation result in a test line of Seoul Metro Line 6 and in a whole line of Busan-Gimhae LRT. The actual ATO pattern can be very accurately simulated by new TPS model with the introduction of 4 parameters such as commercial braking rate, jerk, station stop profile and grade converted distance. The commercial scheduled time for driverless automatic train operation can be proposed to have "Fast" mode TPS trip time plus 3 seconds/km margin recommended by Korean standard LRT specification in this paper.

• Geomechanics and Engineering
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• v.23 no.3
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• pp.245-259
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• 2020

Tunnels have become an indispensable part of metro cities. Blast resistance design of tunnel has attracted the attention of researchers due to numerous implosion event. Present paper deals with the non-linear finite element analysis of rock tunnel having shear zone subjected to internal blast loading. Abaqus Explicit schemes in finite element has been used for the simulation of internal blast event. Structural discontinuity i.e., shear zone has been assumed passing the tunnel cross-section in the vertical direction and consist of Highly Weathered Granite medium surrounding the tunnel. Mohr-Coulomb constitutive material model has been considered for modelling the Highly Weathered Granite and the shear zone material. Concrete Damage Plasticity (CDP), Johnson-Cook (J-C), Jones-Wilkins-Lee (JWL) equation of state models are used for concrete, steel reinforcement and Trinitrotoluene (TNT) simulation respectively. The Coupled-Eulerian-Lagrangian (CEL) method of modelling for TNT explosive and air inside the tunnel has been adopted in this study. The CEL method incorporates the large deformations for which the traditional finite element analysis cannot be used. Shear zone orientations of 0°, 15°, 30°, 45°, 60°, 75° and 90°, with respect to the tunnel axis are considered to see their effect. It has been concluded that 60° orientation of shear zone presents the most critical situation.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.299-305
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• 2017

This study, using the data of the community health survey, chose 2,162 as research objects. To examine convergent neighborhood environmental factors related with walking days of women in their 20s and 30s in Busan city, this study conducted multiple regression analysis. The analysis found out that, the larger the picnic area is, the larger the number of sports facilities is, the larger the number of walking days of those women gets. It was also found out that students walk more often than those who do not work. The older women are, and the larger commercial areas are, the smaller the number of their walking days. Accordingly, it is necessary to design programs suitable to residents in different areas by collecting opinions of residents and testing priorities, necessity, and effectiveness.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.2 s.115
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• pp.113-127
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• 2006

As the local self-government are stabilized and the environmental value is becoming more important among local residents, the occurrence of the anti-movements against waste treatment facilities is getting more frequent. Opposing to build the reuse facilities of wastes takes place because of concerning of health and hygiene, as well as matters of unclear policy making process. However, these facilities must be built in somewhere for the convenience and profit of the public. The NIMBY phenomenon against reuse facilities of wastes could be a burden for the city operation system, and it could worsen citizens' quality of life in the long run. In these lights, reuse and recycling facilities of wastes in East region are necessary facilities improving citizens' quality of life and enhancing the growth of cities in the region. However, there have been concerning of deforestation during the construction process of the facilities. The landscape design presented here for these facilities considers the features of the environmental ecosystem and tries to establish a plan to preserve the natural environment of the City of Ichon. This paper presents methods minimizing adverse effects of the facilities on the existing environments and promoting the city image with integrating culture, tourism, landscape and environment of the city. The landscape design makes efforts to harmonize natural environments in the site, human activities and culture. Well-being park was aimed to lead healthy and energetic outdoor activities of local residents. Ecological park was aimed to enhance the ecological functions of the forests and restore the valley ecology. Culture park was aimed to capture the city identity by creating a place that contains all the variety of meanings of the City of Ichon.

• Journal of the Korean Society of School Health
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• v.23 no.2
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• pp.228-236
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• 2010

Purpose: This research was conducted to compare sex-related knowledge and attitude of 6th-grade elementary school students who participated in the field based learning and those with cooperative learning methods. Methods: The data were collected from June to July in 2009. The subjects of the study were recruited from the classes of the 6th grade conveniently assigned from the D elementary school located in Daejeon metro city. Total of 60 students were assigned either to the field based learning group, and the other 60 students to the cooperative learning group. The field based learning group received sex education at the Daejean Youth Sexuality Culture Center for 3 hours. And the cooperative learning group received sex education by cooperative learning method at the classroom for 40 minutes per session, once a week, for 3 weeks. The sex-related knowledge and attitude scales developed by Lee (2004) were used. The data were analyzed by $x^2$-test, Fisher's exact test, and t-test using the SPSS/WIN V. 12.0 program. Results: The results were as follows. 1. Sex-related knowledge was not significantly different between the cooperative learning and the field based learning group. 2. Sex-related attitude was not significantly different between the cooperative learning and the field based learning group. Conclusion: In this study, sex-related knowledge and sex-related attitude of the cooperative learning group and the field based learning group were different from the lecture method groups in the earlier study. It is worthy of notice that the cooperative learning group and the field based learning group took relatively less time to improve their knowlede and attitude than the earlier lecture based group did.

• Tunnel and Underground Space
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• v.28 no.4
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• pp.304-324
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• 2018

Singapore government is strongly promoting the development and utilization of underground space in national level due to the nature of the city state which lacks the land. As well as conventional underground utilization in shallow depth such as metro and underground roads, large rock cavern utilization has been started after the successful completion of the underground ammunition depot in the rock, and Jurong Rock Cavern, the second large underground cavern project has just been completed. In this paper, after evaluating the conditions of the underground development in rock mass through the analysis of the geology of Singapore, the history and current status of underground development are examined. Several creative development plans from Singapore government such as underground reservoirs, underground automation logistics systems and underground warehouses storage etc. are introduced with technical issues. This paper also discusses the problems and issues related to the development of large underground space in rock mass in Singapore. It is expected that such active development of underground space in Singapore can give many opportunities and also challenges for rock engineering and industry in the future.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.3
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• pp.60-66
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• 2011

The$PM_{10}$ concentrations in the underground should be monitored for the health of commuters on the subway system. Seoul Metro and Seoul Metropolitan Rapid Transit Corporation are measuring several air pollutants regularly. In this paper, the reliability of the instruments using light scattering method is improved with the help of a linear regression analysis technique to measure the $PM_{10}$ concentrations continuously in the subway stations. In addition, an USN monitoring system is implemented to display and record the data of $PM_{10}$, CO/$CO_2$, humidity, and temperature. To transmit and receive these measured sensor data, 2.4GHz Zigbee, 424MHz wireless communication, and CDMA M2M method are applied and evaluated.

• The Korean Journal of Community Living Science
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• v.27 no.spc
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• pp.681-688
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• 2016

This study examined the effective uses of an ecosystem service value assessment in the fields of rural planning and development through archiving and reviewing/analyzing existing concepts, evaluation methods and prior examples of Ecosystem services. Based on land cover analysis, this study evaluated the usability changes in the ecosystem service value for a period spanning 1975 to 2000. The results from the countrywide data survey (with an exception of Jeju island) showed a 33.15% decrease in ESV by 2000. The total ESV represented 5,385 million USD in 1975, and 3,600 million USD in 2000 of the study area. In addition, the ecosystem service value with a scale of metro cities and provinces was also examined. The ESV of most regions decreased by 2000, but Daejeon and Kyeongnam, and Kyeongbuk provinces increased. The trends of year to year changes in the ESV were very diverse throughout the country. Jeonnam showed the smallest decrease, 747 million USD, which is 59% of the ESV in 1975. Nevertheless, the despite the regional differences in available natural resources, the natural resource assets value is ultimately determined by rural development policies and regional economic attributes. Therefore, an ecosystem service must be considered as an important criterion for rural planning and development policy.