• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.461-466
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• 2020

In this study, the relationship between the track support stiffness and the track impact factor for a sleeper floating track and a turnout system with wood ties currently employed in Korean urban transit was assessed by performing field tests using actual vehicles running along the service lines. Field tests were performed on four track systems (i.e., sleeper floating track, and point, lead and crossing sections of turnout system). The theoretically designed track impact factor and track support stiffness were compared with the corresponding track impact factor and track support stiffness measured through field tests for the target tracks on the service line. The track impact factor for the service line appeared to increase with the deviation of track support stiffness according to vehicle driving direction; therefore, it was inferred that the deviation of track support stiffness between each track section directly affected the track impact factor.

• The KIPS Transactions:PartC
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• v.14C no.3 s.113
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• pp.255-266
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• 2007

RSVP (Resource reSerVation Protocol) is the Internet standard protocol for supporting QoS (Quality of Service) requirements by reserving network resources between the sender and the receiver. Several problems, such as common path identification and resource pre-reservation, should be solved to apply RSVP in wireless mobile environments. To resolve these problems, this paper proposes DBRA (Dynamic Branch Router Approach) based on two designated entities, candidate access routers and a branch router. While several RSVP sessions between a branch router and candidate routers are managed, DBRA makes use of only one RSVP session between the sender and a branch router. Based on a network simulation, the proposed scheme has been compared with MRSVP (Mobile RSVP) and HMRSVP (Hierarchical MRSVP) in terms of the average packet transmission rate, bandwidth utilization and RSVP session failure rate.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.8
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• pp.418-425
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• 2005

3D surface reconstruction is to make the original geometry of 3D objects from 2D geometric information. Barequet's algorithm is well known and most widely used in surface reconstruction. It tiles matched regions first, then triangulates clefts using dynamic programming. However it takes considerably long processing time while manipulating complex model. Our method tiles a simple region that does not have branches along minimally distant vertex pairs at once. When there are branches, our method divides contour lines into a simple region and clefts. We propose a fast and simple method that calculates medial axes using a minimum distance in cleft region. Experimental results show that our method can produce accurate models than the previous method within short time.

• Journal of the Korean Society for Railway
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• v.13 no.6
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• pp.570-576
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• 2010

This paper presents the use of the Petri Net Method for modeling railway tracks. The Petri Net is defined as having the characteristics of a parallel, asynchronous, distributed, inconclusive, statistical, etc. information handling system and is a graphical mathematical modeling tool to study the specifics of active movement. It's proven use can be seen at the Korean type Light Rail testing tracks where they modelled the Petri Net method using the train track encasing the segment, track, turnout, and platform as a singular factor and even though two trains either travelling in the same or opposite directions on a single test track equipped with a sidetrack can travel with the guarantee that the two will not collide.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.400-402
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• 2019

The electric point machine, which is used for the control of the turnout used to change the track of the train, is very important in the railway system. Various wired and wireless real-time monitoring systems are used to check the status of the point machine, but there is a possibility of malfunction due to sensor or network error. In this paper, a redundant monitoring system was designed that incorporates the point machine monitoring system and the CCTV camera control system to double check the operation of the point machine. In the point machine monitoring system, the operating state of the railway converter is monitored, alarmed and transmitted over the network. The CCTV camera control system, which received this information, was required to record the status of the turnout and the point machine in question and send it to the administrator. The manager of the railway line can check the conversion status of the railway through the monitoring screen for the railway line switcher first, and then confirm the switching status directly through the CCTV camera image, thereby improving the reliability of the point machine operation. It will also enable the safe and efficient operation of personnel for management. It is expected to contribute to preventing a derailment caused by a malfunction of the point machine.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.477-482
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• 2022

The structure of the turnout track is very complex, so it is a facility that is more difficult to maintain and requires detailed management than a general track type. The purpose of this study is to analyze the effect on the deformation of the turnout system of the ground section due to the excavation work adjacent to the serviced urban railways. In this study, based on finite element analysis for each stage of adjacent excavation, the track deformation for each major location of turnout system was analyzed in consideration of the layout of the turnout system installed on the ground section, and the safety and stability was confirmed by comparing it with the track irregularity regulation. As a result of the study, it was found that the major construction stage affecting the track deformation of the turnout system on the ground section was the final stage of excavation. In addition, although the vertical displacement which is a vertical irregularity occurred relatively large, it was analyzed that the horizontal deformation was dominant overall, because of the excavation site is located on the side of the turnout system. In addition, it was analyzed that the amount of displacement at each major location of the turnout system is different, and there is a possibility that there may be a twist irregularity due to the deviation of the track deformation for each location according to the distance from the excavation site. Therefore, it was analyzed that it is necessary to classify and manage the importance of the track deformation of the turnout system of actual operating line, including additional displacement due to adjacent excavation, based on the track irregularity that has occurred at each location where the major deformation characteristics occur.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.537-543
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• 2004

In order to create three-dimensional model for human body, a method that reconstructs geometric models from contour lines on cross-section images is commonly used. We can get a set of contour lines by acquiring CT or MR images and segmenting anatomical structures. Previously proposed method divides entire contour line into simply matched regions and clefts. Since long processing time is required for reconstructing cleft regions, its performance might be degraded when manipulating complex data such as cross-sections for human body. In this paper, we propose a fast reconstruction method. It generates a triangle strip with single tiling operation for simple region that does not contain branch structures. If there exist branches in contour lines, it partitions the contour line into several sub-contours by considering the number of vertices and their spatial distribution. We implemented an automatic surface reconstruction system by using our method which reconstructs three-dimensional models for anatomical structures.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.5
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• pp.823-837
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• 2018

Congestion of the city with the rapid industrial development was accelerated to build complex social infrastructure. And numerous structures have been designed and constructed in accordance with these requirements. Recently, to solve complex urban traffic, many researches of large-diameter tunnel under construction downtown are in progress. The large-diameter tunnel has been developed with a versatile double-deck of deep depth tunnel. For the safe tunnel construction, ground reinforcement methods have been developed in the weakened pillar section like as junction of tunnel. This paper focuses on evaluation of the effects of new developed ground reinforcement methods in double-deck junction. The values of reinforcement determined from the existing and developed methods were compared to each other by numerical simulation.

• Journal of the Korea Society of Computer and Information
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• v.19 no.11
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• pp.63-72
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• 2014

In this paper, we propose a sign language recognition system using SVM and depth camera. Especially, we focus on the Korean sign language. For the sign language system, we suggest two methods, one in hand feature extraction stage and the other in recognition stage. Hand features are consisted of the number of fingers, finger length, radius of palm, and direction of the hand. To extract hand features, we use Distance Transform and make hand skeleton. This method is more accurate than a traditional method which uses contours. To recognize hand posture, we develop the decision tree with the hand features. For more accuracy, we use SVM to determine the threshold value in the decision tree. In the experimental results, we show that the suggested method is more accurate and faster when extracting hand features a recognizing hand postures.

• Journal of the Korean Geotechnical Society
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• v.24 no.2
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• pp.45-57
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• 2008

The improved turnout system is developed to speed-up the pre-existing railroad. The research has been actively carried out far the improved turnout system and the impact factor is estimated using the data sets achieved from the dynamic wheel-load field tests in both the conventional and the improved turnout system. In this study, the track performance and roadbed behavior are examined for the conventional and improved turnout system using the estimated impact factor. Dynamic wheel load and rail pressure are evaluated to assess the track performance. Roadbed stress and settlements are estimated using numerical analysis. Additionally, the stability of roadbed is estimated in soft roadbed condition influenced by the weather effects and cyclic train loading. The results show that dynamic wheel load, rail pressure, roadbed stress, and roadbed settlements in the improved turnout system substantially decrease compared with those in the conventional turnout system.