• 한국철도학회논문집
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• 제4권2호
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• pp.47-54
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• 2001

Railway companies have been faced with many changes in the railway environment. To cope immediately with the influence of environment and to improve productivity, an efficient train operation system and related core technologies must be introduced. The railway system is composed of large scale infrastructures and high-cost trains. Simulation method is one of core technologies and also efficient tool for planning and analyzing these kinds of complex system. In this research, we review basic simulation programming models and present a modeling for the elements of railway system such as rail-line infrastructure, train, time table and operational route. Additionally, some considerations on the development of multi-train traffic simulator for KyongBu-line are discussed.

• 대한한의학회지
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• 제40권2호
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• pp.72-88
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• 2019

Objectives: The purpose of this study is to understand the experience of traffic accident patients with serious injury treated with Traditional Korean Medicine (TKM). Methods: This study was conducted on the basis of grounded theory. We recruited 10 participants who had been hospitalized in Dongguk University Bundang Oriental Hospital after traffic accident. Raw data was collected by in-depth interview, and analyzed by using constant comparison. The coding(open-axial-selective) was performed in order to create paradigm and theoretical model, which can explain main theme of this study. Results: Core phenomenon of this study was 'Experiencing TKM treatment as an alternative' and core category was 'Searching for the answer to the management of traffic accident sequela through TKM treatment' Conclusions: For patients with serious injury, 'Experiencing TKM treatment as an alternative' has meaning as the following: First, The absence of accurate radiography and surgical management makes it hard for patients to choose Korean medicine hospital immediately after traffic accident. Second, Effectiveness of TKM treatment should be evaluated in the long term. Third, TKM treatment is superior to Western medicine treatment in managing long-term patients who suffered from serious injury involved in traffic accident. Finally, Cooperative service of the Western medicine and TKM will provide more satisfactory medical care for traffic accident patients.

• 인터넷정보학회논문지
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• 제22권5호
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• pp.9-16
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• 2021

Recently, the traffic volume of mobile communications increases rapidly and the small-cell is one of the solutions using two offload schemes, i.e., local IP access (LIPA) and selected IP traffic offload (SIPTO), to reduce the end-to-end delay and amount of mobile data traffic in the core network (CN). However, 3GPP describes the concept of LIPA and SIPTO and there is no decision algorithm to decide the path from source nodes (SNs) to destination nodes (DNs). Therefore, this paper proposes a dynamic mobile data traffic offload scheme using small-cells to decide the path based on the SN and DN, i.e., macro user equipment, small-cell user equipment (SUE), and multimedia server, and type of the mobile data traffic for the real-time and non-real-time. Through analytical models, it is shown that the proposed offload scheme outperforms the conventional small-cell network in terms of the delay of end-to-end mobile data communications and probability of the mobile data traffic in the CN for the heterogeneous networks.

• International journal of advanced smart convergence
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• 제12권4호
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• pp.88-97
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• 2023

Traffic flow prediction is of great significance in urban planning and traffic management. As the complexity of urban traffic increases, existing prediction methods still face challenges, especially for the fusion of spatiotemporal information and the capture of long-term dependencies. This study aims to use the fusion model of graph neural network to solve the spatio-temporal information fusion problem in traffic flow prediction. We propose a new deep learning model Spatio-Temporal Information Fusion using Graph Neural Networks (STFGNN). We use GCN module, TCN module and LSTM module alternately to carry out spatiotemporal information fusion. GCN and multi-core TCN capture the temporal and spatial dependencies of traffic flow respectively, and LSTM connects multiple fusion modules to carry out spatiotemporal information fusion. In the experimental evaluation of real traffic flow data, STFGNN showed better performance than other models.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.162-167
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• 1999

ATM technology is well developed. Small-scale access node and edge switches are introduced in the network. Large scale ATM core switches are prepared for backbone application. Currently, Internet traffic is increasing so rapidly and we need to consider effective way of accommodating the volume of traffic. In the other hand, QoS and traffic engineering concept is required in the Internet services. Here, in this paper, two technologies are explained and suggested for integration of networks for future ATM based IP network.

• 대한전자공학회논문지TC
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• 제43권6호
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• pp.9-22
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• 2006

기존 멀티캐스트 라우팅 프로토콜들을 IP기반 모바일 코어 네트워크에서 도입하였을 때, 불필요한 소스들로부터의 트래픽 유입과 그룹 제어 메시지 오버헤드 및 대용량의 멀티캐스트 세션 정보로 인한 라우터 효율 저하 둥의 문제점들이 있다. 본 논문에서 제안하는 방식은 무상태 멀티캐스트 방식을 기반으로 하기 때문에 각 멀티캐스트 라우터에는 특별히 멀티캐스트 세션을 위한 상태정보를 유지할 필요가 없으며, 멀티캐스트 트리의 상태유지를 위한 불필요한 네트워크 오버헤드를 감소시킬 수 있다. 더불어, TGMPv3와 연동함으로써 수신자들이 가입하지 않은 불필요한 멀티캐스트 소스 트래픽을 제거한다. 기존 인터넷 멀티캐스트 망과의 연동 게이트웨이 노드, 무선망과의 투명성을 위한 게이트웨이 노드 및 모바일 코어 네트워크의 중간 노드 등의 주요 구성 요소 등에 대한 동작을 정의하여 제안하는 통신 아키텍쳐를 완성한다. 마지막으로 본 논문에서 제안하는 아키텍쳐의 우수성을 네트워크 모의실험을 통해 검증한다.

• 대한임베디드공학회논문지
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• 제9권3호
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• pp.145-150
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• 2014

This paper presents an effective vision based method for LED traffic light detection at the daytime. First, the proposed method calculates horizontal coordinates to set region of interest (ROI) on input sequence images. Second, the proposed uses color segmentation method to extract region of green and red traffic light. Next, to classify traffic light and another noise, shape filter and haar-like feature value are used. Finally, temporal delay filter with weight is applied to remove blinking effect of LED traffic light, and state and weight of traffic light detection are used to classify types of traffic light. For simulations, the proposed method is implemented through Intel Core CPU with 2.80 GHz and 4 GB RAM, and tested on the urban and rural road video. Average detection rate of traffic light is 94.50 % and average recognition rate of traffic type is 90.24 %. Average computing time of the proposed method is 11 ms.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.147-148
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• 2007

BICC protocol is a relay protocol adaptable to ATM and IP based core networks compared to ISUP protocol to TDM networks. Using BICC protocol, multi-rate bearer traffic such as voice and video can flow in the relay core networks. BICC protocol is standardized as WCDMA circuit switching networks in 3GPP Release 4. Thus KTF is now operating core networks using BICC protocol. In this paper, we describe the background and characteristics of BICC protocol. We also provide the status of KTF WCDMA core networks using BICC. To show the efficiency of BICC protocol an analytical simulation is given in which the results can be expected by intuitive observation.

• 한국정보통신학회논문지
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• 제11권7호
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• pp.1332-1340
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• 2007

본 논문에서는 휴대인터넷 와이브로 (WiBro) 시스템의 보안계층 중 암호 키 (Traffic Encryption Key; TEK)를 암호 복호하는 key wrap/unwrap 알고리듬의 효율적인 하드웨어 설계에 대해 기술한다. 설계된 key wrap/unwrap 코어 (WB_KeyWuW)는 AES (Advanced Encryption Standard) 알고리듬을 기반으로 하고 있으며, 128비트의 TEK를 128비트의 KEK (Key Encryption Key)로 암호화하여 192비트의 암호화된 키를 생성하고, 192비트의 암호화된 키를 복호화하여 128비트의 TEK로 복호하는 기능을 수행한다. 효율적인 하드웨어 구현을 위해 라운드 변환 블록에 하드웨어 공유기법을 적용하여 설계하였으며, 또한 하드웨어 복잡도에 가장 큰 영향을 미치는 SubByte/InvSubByte 블록을 체 변환 방법을 적용하여 구현하였다. 이를 통해, LUT (Lookup Table)로 구현하는 방식에 비해 약 25%의 게이트 수를 감소시켰다. Verilog-HDL로 설계된 WB_KeyWuW 코어는 약 14,300개의 게이트로 구현되었으며, 100-MHz@3.3-V의 클록으로 동작하여 $16{\sim}22-Mbps$의 성능이 예상되어 와이브로 시스템 보안용 하드웨어 구현을 위한 IP로 사용될 수 있다.

• 디지털산업정보학회논문지
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• 제6권2호
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• pp.153-167
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• 2010

Traffic conditions, in particular number of active TCP flows, change dramatically over time. The main goal of this paper is an adaptive queue management algorithm that can maintain network state of high-throughput and low-delay under changing traffic conditions In this paper, we devise Probability Adaptive RED(PARED) that combines the more effective elements of recent algorithms with a RED core. It automatically adjusts its adaptive marking function to account for changes in traffic load and to keep queue length within the desired target queue length. We simulate that PARED algorithm results in under changes in traffic load and mixed traffic load. The simulation test confirm this stability, and indicate that overall performances of PARED are substantially better than the RED and ARED algorithms.