• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.427-436
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• 2018

HADAX is a serial communication converter of train control computer. It is connected with various signal equipments such as wayside signal equipments, station signal equipments, train control computers, and transmits control information and signal condition information for train control. And transmits information to several electronic interlocking devices through a splitter interface. Since HADAX interfaces with many signaling devices through serial communication, frequent communication connection faults necessitate improvement of performance such as dual system configuration, integration of external splitter, and multi-channelization of communication card. The improved HADAX device should have compatibility with the dimensions of existing enclosure and enclosure, and verify the performance of dual system and splitter integration. Therefore, we verified the performance of HADAX through the route control test, dual system test, and multi-channel communication test with splitter integrated connection by connecting with the existing signal equipment.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.517-522
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• 2021

In this study, the causes of damage to the concrete sleepers in a ballast track with under sleeper pads attached to the base of the sleepers installed in the sharp curved track(R=180m) of the urban railway bridge were analyzed. The damage types of concrete sleepers were investigated, and the correlation with track irregularity was reviewed. Also, stress generated in the concrete sleeper was reviewed through structural analysis. As a result, most of the cracks of the sleepers occurred in the section with severe track irregularity. In addition, as a result of the analysis, the stress generated in the track components and the sleepers was found to be reduce in the fastening system using the 4-anchor.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.407-413
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• 2022

In this study, the empirical formula for evaluating cable tension based on long-term measurement for about 3 years according to temperature change was proposed by proving the correlation between the expansion joint displacement of the upper road bridge and the cable tension of the lower railway bridge. The tension prediction results using the empirical formula for tension evaluation each cables proposed in this study were found to be in good agreement with the cable tension using the vibration method within 3%. Therefore, it was analyzed that it could be applied together with the vibration method that was an experimental technique, to predict and evaluate the cable tension in serviced railway steel composite bridge. As a result of applying the estimated temperature calculated by the empirical formula for expansion proposed in this study to the empirical formula, it was analyzed that a high level of reliability could be secured when compared with the vibration method. Therefore, it is judged that the empirical formula for cable tension evaluation reflecting the estimated temperature proposed in this study can be used to predict the tension of cables according to climate change in the future and establish a maintenance plan.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.265-270
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• 2022

The purpose of this study is to derive the damage weak part of the elastic rail fastening system for concrete tracks (System 300-1). In the concrete tracks, the elastic rail fastening system sticks the rail and the sleeper and reacts all the time when the train is running. Among the components of the rail fastening system, the resilience pad and tension clamp were fatigue members and were constantly deformed in response to compressive and uplift forces. In this study, the residual deformation characteristics of the tension clamp according to the period of use were analyzed using by specimens taken on site in the same section for 6, 11, and 16 years on the serviced urban transit. In addition, the damage mechanisms for each component were derived based on finite element analysis. As a result of the numerical analysis, the stress (strain) of each part of the tension clamp according to the external force from the applied clamping force was analyzed to derive the damaged weak part of the tension clamp.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.727-732
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• 2022

Applying the calculated cross-sectional reduction due to the corroded rebar investigated in the field to the numerical analysis model, the damage pattern and delamination of concrete in the field showed a tendency relatively similar to the numerical analysis results. It was analyzed that when the expansion pressure due to corrosion of the reinforcing bar is greater than the tensile stress of the concrete, cracks are generated and the concrete cover can be fracture. As a result of this study, the correlation between the corrosion rate of reinforcing bars and the crack occurrence of the concrete cover of the subway box structure was verified based on the numerical analysis and field test results. To prevent rebar corrosion, the corrosion rate can be reduced by applying rust prevention to the reinforcing bar and changing the material. In the case of exposed to a corrosive environment, the tensile strength of the concrete is improved by adjusting the concrete compressive strength to secure durability against the expansion pressure caused by the corroded rebar.

• Journal of the Korean Geosynthetics Society
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• v.21 no.2
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• pp.11-19
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• 2022

In this paper, we propose a GoogleNet transfer learning and CNN-LSTM combination method to improve the time-series prediction performance for crack detection using crack data captured inside the sewer pipes. LSTM can solve the long-term dependency problem of CNN, so spatial and temporal characteristics can be considered at the same time. The predictive performance of the proposed method is excellent in all test variables as a result of comparing the RMSE(Root Mean Square Error) for time series sections using the crack data inside the sewer pipe. In addition, as a result of examining the prediction performance at the time of data generation, the proposed method was verified that it is effective in predicting crack detection by comparing with the existing CNN-only model. If the proposed method and experimental results obtained through this study are utilized, it can be applied in various fields such as the environment and humanities where time series data occurs frequently as well as crack data of concrete structures.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.1
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• pp.141-148
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• 2023

Purpose : This study examined the relationship between suicidal thoughts, hand grip strength, socioeconomic status, educational level, and disease occurrence. Methods : Korean national health and nutrition examination survey 2017 were used in this study. 5,449 were analysed. For comparison between groups, cross-tabulation analysis and mean comparison were performed. Logistic regression analysis were performed to analyze the influencing factors between grip strength and suicidal ideation. Results : Our results are consistent with the literature on the importance of socioeconomic status in health. The lower the level of education, the higher the suicidal thoughts. Being single or divorced was also significantly associated with suicidal ideation. Moreover, a lower income level was significantly associated with a higher suicide intention. Furthermore, older ages, lower educational levels, and lower income were significantly associated with a higher odds ratio of suicidal thoughts. Interestingly, suicidal thoughts were significantly lower among non-smokers. In contrast, suicide intention did not differ significantly according to gender, age, monthly drinking habit, aerobic physical activity, and disease occurrence. Suicidal thoughts decreased as grip strength increased and this was statistically significant. Socioeconomic status, disease occurrence, and handgrip strength level affected the security of an individual's livelihood and were significant risk factors for suicidal thoughts. These associations remained significant in multiple logistic regression even after controlling for all covariates. Conclusion : Future prevention intervention efforts to reduce suicide risks should consider handgrip strength. Studies to explore the possible proximal risk factors and mediators between handgrip strength and suicidal thoughts are also warranted.

• Journal of Korean Society of Rural Planning
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• v.28 no.4
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• pp.19-29
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• 2022

This study aimed to estimate the impervious area rate by rural water districts in 2009 and 2021 and analyze the changes. From the EGIS(Environmental Geographic Information Service) land cover maps, the impervious areas were defined as residential, commercial, industrial, culture·sports·recreational, traffic, public facilities, and greenhouses of land cover classes. For 496 rural water districts excluding the border area with North Korea, the nationwide impervious area rate increased from 5.96% in 2009 to 7.50% in 2021. The average of the top 50 rural water districts increased from 23.4% in 2009 to 27.1% in 2021. E ven for the bottom 50 rural water districts, the average impervious area rate rose from 1.12% in 2009 to 1.40% in 2021. Rural water districts with a high impervious area rate are mainly distributed in metro cities and industrial areas. The contraries are primarily found in Gangwon, Gyeongsang, and Jeolla regions covered with forests and farmlands. Notably, the impervious area rate changed more in the neighboring rural water districts than in large cities, and the rate kept increasing slightly even in rural areas with a low impervious area rate. The findings of this study will help prepare a reasonable alternative for managing the impermeable surface of rural areas for safe and sound rural water cycle.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.277-282
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• 2022

The sleeper floating track (STEDEF) in this study was a track type in which a very soft resilience pad was installed under a relatively thin concrete sleeper (RC Block). Therefore it was expected that the resilience pad could affect the estimation results of the concrete strength. In this study, field applicability evaluation was performed to apply the rebound hardness test method, which was a general method for estimating the compressive strength of concrete in civil structures, to concrete sleepers of railway tracks. In order to analyze the strength estimation technique of concrete sleepers reflecting the characteristics of track structures different from those of civil structures, the parameter experiments that could affect the strength estimation results of concrete sleepers in a serviced line were performed. As a result of the study, the appropriate hitting position was suggested considering the shape of the concrete sleeper, and the difference in strength estimation results according to the condition of the concrete sleeper and supporting conditions was derived.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.633-638
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• 2023

In this study, the effect of the change in cable tension on the track irregularity of railway ballasted track on a railway steel composite bridge was analyzed. As a result of comparing design and analysis results for cable tension, a difference of less than 3% was found, and analysis modeling was analyzed to reflect the design conditions well. In addition, the adequacy of the analysis modeling was demonstrated by comparing the field measurement results with the analysed cable tension. By considering the change in cable tension as a variable, the track irregularity of the railway steel composite bridge was analyzed. As a result of the analysis, it was analyzed that the total and one-sided cable tension change had a direct effect on the vertical irregularity among the track irregularity items. In addition, it was found that the change in track irregularity occurred in the section close to the cable position. It was analyzed that the change in cable tension had a more direct effect on track irregularity that had a direct correlation with the vertical direction rather than the lateral direction.