• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.47 no.1
• /
• pp.41-51
• /
• 2010

In the research for driver assistance systems, traffic sign information to the driver must be a very important information. Therefore, the detection system of traffic signs located on the road should be able to handel real-time. To detect the traffic signs, color and shape of traffic signs is to use the information after images obtained using the CCD camera. In the road environment, however, using color information to detect traffic sings will cause many problems due to changes of weather and environmental factors. In this paper, to solve it, the candidate traffic sign regions are detected from road images obtained in a variety of the illumination changes using the HSI eign-color model. And then, using the invariant moment-based SVM classifier to detect traffic signs are proposed. Experimental results show that, traffic sign detection rate is 91%, and the processing time per frame is 0.38sec. Proposed method is useful for real-time intelligent traffic guidance systems can be applied.

• Journal of Communications and Networks
• /
• v.7 no.3
• /
• pp.377-384
• /
• 2005

The purpose of this research is to develop and evaluate a traffic engineering architecture that uses local state information. This architecture is applied to an Internet protocol radio access network (RAN) that uses multi-protocol label switching (MPLS) and differentiated services to support mobile hosts. We assume mobility support is provided by a protocol such as the hierarchical mobile Internet protocol. The traffic engineering architecture is router based-meaning that routers on the edges of the network make the decisions onto which paths to place admitted traffic. We propose an algorithm that supports the architecture and uses local network state in order to function. The goal of the architecture is to provide an inexpensive and fast method to reduce network congestion while increasing the quality of service (QoS) level when compared to traditional routing and traffic engineering techniques. We use a number of different mobility scenarios and a mix of different types of traffic to evaluate our architecture and algorithm. We use the network simulator ns-2 as the core of our simulation environment. Around this core we built a system of pre-simulation, during simulation, and post-processing software that enabled us to simulate our traffic engineering architecture with only very minimal changes to the core ns-2 software. Our simulation environment supports a number of different mobility scenarios and a mix of different types of traffic to evaluate our architecture and algorithm.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.2
• /
• pp.162-169
• /
• 2009

The real-time traffic data is generated continuous and unbounded stream data type while intelligent transport system (ITS) needs to provide various and high quality services by combining with spatial information. Traditional database techniques in ITS has shortage for processing dynamic real-time stream data and static spatial data simultaneously. In this paper, we design and implement an advanced traffic monitoring system (ATMS) with the integration of existed data stream management system (DSMS) and spatial DBMS using IntraMap. Besides, the developed ATMS can deal with the stream data of DSMS, the trajectory data of relational DBMS, and the spatial data of SDBMS concurrently. The implemented ATMS supports historical and one time query, continuous query and combined query. Application programmer can develop various intelligent services such as moving trajectory tracking, k-nearest neighbor (KNN) query and dynamic intelligent navigation by using components of the ATMS.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.10A
• /
• pp.930-937
• /
• 2005

In this paper, a processing time and traffic capacity analysis algorithm for RFID system using LBT-serial searching scheme is proposed. Service time, carrier sensing time, additional delay time required for contiguous frequency channel occupancy, and additional delay time required for the contiguous using the same frequency channel are considered and the processing delay and frequency channel capacity are analyzed for the steady state operation of the system. The simulation results showing maximum capacity of the system and explaining the accuracy of the algorithm are provided.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.7
• /
• pp.758-766
• /
• 1992

In this paper, the traffic control scheme used by M-cancel-Get services In CMIS /CMIP, OSI network management protocol, is presented and the performance is analyzed. M -Get service which allows a multiple response functional unit is a service that searches an attribute of the managed sys-tem and the service requires a large quantity of response as its typical characteristics. At the time, management response is transmitted Irrelevant to the network condition In the managed as well as In the management system. The management system requests M Canrel-Get service which informs the canrelation of M -Get service (or Information retrieval. In case of using M-Cancel-Get service for traffic control, the point of time for traffic control is propose by the result of simulation on management response time as the number of multiple response packets is Increased. The result is analyzed by processing ratio of the network workload and the average delay time of packets. As a result, the traffic control parameters proposed in the study show superiority in its processing ratio and the average packet delay time. Especially, its performance improves as the size of background traffic density Increase.

• IEIE Transactions on Smart Processing and Computing
• /
• v.4 no.4
• /
• pp.237-250
• /
• 2015

This paper describes a hardware-oriented algorithm and its conceptual implementation in a real-time speed limit traffic sign detection system on an automotive-oriented field-programmable gate array (FPGA). It solves the training and color dependence problems found in other research, which saw reduced recognition accuracy under unlearned conditions when color has changed. The algorithm is applicable to various platforms, such as color or grayscale cameras, high-resolution (4K) or low-resolution (VGA) cameras, and high-end or low-end FPGAs. It is also robust under various conditions, such as daytime, night time, and on rainy nights, and is adaptable to various countries' speed limit traffic sign systems. The speed limit traffic sign candidates on each grayscale video frame are detected through two simple computational stages using global luminosity and local pixel direction. Pipeline implementation using results-sharing on overlap, application of a RAM-based shift register, and optimization of scan window sizes results in a small but high-performance implementation. The proposed system matches the processing speed requirement for a 60 fps system. The speed limit traffic sign recognition system achieves better than 98% accuracy in detection and recognition, even under difficult conditions such as rainy nights, and is implementable on the low-end, low-cost Xilinx Zynq automotive Z7020 FPGA.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.11b
• /
• pp.1077-1080
• /
• 2003

본 연구는 룰들의 각 필드들을 index하여 곱한 cross-product 테이블을 이용한 packet classification 알고리즘에 대해 연구하고 그 것의 성능을 평가하고 분석한다. 현재 Packet Classification은 Packet Filtering, Policy Routing, Accounting & Billing, Traffic Rate Limiting, Traffic Shaping, 등등의 서비스를 위한 가장 핵심적인 작업이다. 그러나 이들을 빠르게 서비스하는 알고리즘은 아직 존재하지 않는다. 단지 하드웨어 TCAM 을 이용해서 작은 룰들에 대한 처리만이 어느 정도 가능한 실정이다. 이에 본 연구는 소프트웨어를 이용한 cross-product 알고리즘의 효용성을 가늠하고자 연구하고 이를 실제 구현해 평가하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.04a
• /
• pp.340-345
• /
• 2000

본 논문에서는 대용량 통신처리시스템의 트래픽 처리 능력 예측을 위해 실제 네트워크 구축 상황과 서비스 상황을 모의로 만들어 줄 수 있는 테스터 소프트웨어 개발을 목적으로, 리눅스환경에서 Network Traffic Generator, Remote노드에 사용될 패킷 귀한 프로그램, Statistcal Analyzer, GTK+ 라이브러리를 이용한 GUI, Network Traffic Generator와 Statistical Analyzer를 하나의 프로그램 안에서 동시에 동작하도록 하는 Thread 사용 기법이 연구되었다. 이를 이용하여 대용량 통신 처리시스템의 성능 규격의 정확한 확인을 통해 가용 가능한 가입자 노드의 용량을 결정할 수 있으며, 상용현장시험이 가능하고 또한 설치 규격을 제공할 수 있다.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.6
• /
• pp.927-936
• /
• 1995

ATM Forum has defined a new service class for data applications called Available Bit Rate(ABR) Service, which has highly bursty traffic and unpredictable burst size. It is desirable that we reduce the probability of retrans mission of packets by minimizing the loss of cells because the traffic is much more sensitive to loss than delay. The Forum has also selected the Rate-Based Control for the ABR service and proposed EPRCA as the control mechanism for the service. This paper proposes the combination of EPRCA and the other feedb ack control mechanisms such as BECN and BP. The combined control mechanism control ABR traffic more efficiently and the simulation results show that the network performance can be improved by choosing the appropriate parameters.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.4
• /
• pp.1246-1264
• /
• 2000

An input-output buffering switch operates in either of tow different cell loss modes; Backpressure mode and Queueloss mode. In the previous studies, the Backpressrue mode is more effective at low traffic loads, and the Queueloss mode performs better at high traffic. We propose a new operation mode, called Hybrid mode, which adopts the advantages of he Backpressure and the Queueloss mode. Backpressure and Queueloss modes are distinguished from whether a cell loss occurs at the output buffer or not when output buffer overflows, irrespective of input buffer status. In order to simply combine Backpressure and Queueloss mode, the change of input traffic load must be measured. However, in the Hybrid mode, simply both of the input and output buffer overflow and checked out to determine the cell discard. The performance of the Hybrid mode is compared with those of the Backpressure and the Queueloss mode under random and bursty traffic. This paper show that the Hybrid mode always gives the best performance results for most ranges of load values.