• 전자공학회논문지S
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• 제35S권3호
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• pp.1-8
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• 1998

In this paper, we propose a Neural Call Admission Control (CAC) method using a Sparse Distributed Memory(SDM). CAC is a key technology of TM network traffic control. It should be adaptable to the rapid and various changes of the ATM network environment. conventional approach to the ATM CAC requires network analysis in all cases. So, the optimal implementation is said to be very difficult. Therefore, neural approach have recently been employed. However, it does not mett the adaptability requirements. because it requires additional learning data tables and learning phase during CAC operation. We have proposed a neural network CAC method based on SDM that is more actural than conventioal approach to apply it to CAC. We compared it with previous neural network CAC method. It provides CAC with good adaptability to manage changes. Experimenatal results show that it has rapid adaptability and stability without additional learning table or learning phase.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.310-314
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• 2010

Track geometry changes by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies in Korea use normal distribution as probability distribution of track irregularity. But some countries use non-normal distribution according to their own track recording system. In this report, reviewed probability distribution of Kyung-Bu high-speed line and tested normality.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.113-120
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• 2001

A frame slab method has been proved as a possible and profitable construction solution for the urban tunnels with very shallow overburden and the excavation from the surface Is strictly limited. Since this method allows only a small amount of construction activities in the ground surface, the disturbances to the public and the surface traffic can be drastically reduced compared with the ordinary cut-and-cover method. The construction sequences of the method and the some of critical cautions needed are described in detail. Also a comprehensive numerical analysis including 2-D and 3-D analysis have been performed to verify the stability of the ground during the construction. It is revealed from this study that the frame slab method can be a quite successful solution for the shallow overburden tunnelling in urban area.

• 한국멀티미디어학회논문지
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• 제21권9호
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• pp.1090-1098
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• 2018

MQTT is a lightweight messaging protocol that can be used for low power IoT devices. The MQTT basically uses single MQTT broker to indirectly share message information between publishers and subscribers. This approach has a weakness in regard to traffic overflow, connection fault, security, etc. In this paper, we propose a distributed MQTT broker architecture that solves the problems in single MQTT broker structure. The distributed MQTT broker architecture is expected to support new application services that cannot be supported by a conventional MQTT architecture. We have designed and implemented a distributed MQTT broker architecture based on the RPL protocol that has been widely used for IoT network. The experiment results show that the proposed MQTT broker architecture represents better publishing/subscribing latency and network stability than the conventional MQTT broker architecture.

• 한국응용과학기술학회지
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• 제20권4호
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• pp.353-357
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• 2003

Sodium azide (SA) is commonly used as propellant for inflating automatic safety bags and other chemical manufacturing purposes. The investigation of potentially thermal hazard of sodium azide and its mixture with polymers are very important because it can occur an expected traffic accident so we took a experiment s using different scanning calorimeter (DSC) in nitrogen atmosphere. The decomposition temperature were about $350{\sim}450^{\circ}C$. We could find not only exothermic reaction was remarkably decreased in mixture s of acrylonitrile-butadiene-styrene (ABS) and polyvinyl chloride (PVC), but also increasing mixed rate of ABS, polyvinyl alcohol (PVA) and polymethyl methacrylate (PMMA) decreased thermal decomposition heat.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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• pp.177-184
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• 2002

The concrete median barriers are the most popular safety appurtenances that can be installed on narrow medians and are effective in keeping uncontrolled vehicles from crossing into opposing lanes of traffic. It is necessary to install and maintain median barriers because it is very difficult to reserve enough room required for medians in KOREA. And concrete median barriers are accepted as the actual alternatives for median barriers, mostly because they require almost no maintenance even after serious collisions. Typical concrete median barriers are 810mm high and have 596mm high glare screens on top of them. But we have experienced a number of “climb” and “roll-over” accidents of heavy vehicles until now, and most of all, there have been some serious accidents caused by the part of broken glare screens. We have performed many computer simulations for the evaluation of the crashworthiness of concrete median barriers, and through the simulations we have tried to find a proper type of concrete median barrier.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 추계학술발표대회
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• pp.716-719
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• 2017

본 시스템은 자율 주행 버스를 위한 시스템이다. 딥러닝(Deep Learning) 기반 컴퓨터 비전 기술을 이용해 차선과 물체 인식을 하여 버스를 제어하는 방식으로 자율 주행을 가능하게 하는 시스템으로 교통비 완화 및 안정성 증대를 기대할 수 있다.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1999년도 추계학술대회 논문집
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• pp.93-99
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• 1999

The service level of Metro stations is affected by the design criteria such as platform area, width and length of stairways, and the number of turnstile, etc. The Korean station design process utilizes peak-hour volume as design volume. Hourly volume, however, can not explicitly account for the variation of traffic and consequently the variation of the level of service within the one-hour time period. Movements in various areas inside of stations are simulated with a queueing network under various operating conditions. A discrete simulation tool called SIMUL8 was utilized. Based on the results, peak volume for 15 minutes period was recommended as a preferred base volume over the peak-hour volume for station design purpose to realistically account for user delays under. Simulation runs also confirmed that escalators have positive effects on passenger processing capacity and on securing stability of passenger flows in stations.

• International Journal of Railway
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• 제9권1호
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• pp.15-20
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• 2016

An approach section on an abutment is located between the soil embankment and the structure, which may cause an uneven surface due to different settlement between the abutment and the soil embankment. This study proposes a new type of wall which separates the abutment from the backfill material using mechanically stabilized wall. A new type of keystone which incorporates geotube and wire mesh is proposed and evaluated. Numerical analyses were performed to investigate the applicability of the proposed keystone type, which incorporates Geosynthetic. The maximum horizontal displacements along GRS wall faces, settlements at the top of pavement and track bed, and tensile forces applied on geotextiles under traffic loads were investigated. The results of the numerical analysis showed that the proposed wall can be used for highway and high-speed railway abutment.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 암반역학위원회 학술세미나 논문집
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• pp.165-193
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• 2003

The Han River tunnel connecting Yoido and Mapo was constructed as a part of the Seoul subway line No.5, which is 52 km long, to improve the traffic conditions of Seoul. It is constructed 15.6∼30m below the river floor. It Is the first under-river tunnel in Korea with the length of 1,288m. Geological conditions of the ground under the Han River were more complex and irregular than expected at the design stage, because there were several faults, fracture zones and slickensided joints coated with graphite. It was thus indispensable to estimate the ground condition of the tunnel face to apply proper excavation and reinforcement methods. Advance borings and face mappings were performed before excavation to improve constructional efficiency and excavation stability.