• Journal of Information Processing Systems
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• v.2 no.3 s.4
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• pp.183-188
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• 2006

A RMON agent system, which locates on a subnet, collects the network traffic information for management by retrieving and analyzing all of the packets on the subnet. The RMON agent system can miss some packets due to the high packet analyzing overhead when the number of packets on the subnet is huge. In this paper, we have developed a light-weight RMON agent system that can handle a large amount of packets without packet loss. Our RMON agent system has also been designed such that its functionality can be added dynamically when needed. To demonstrate the dynamic reconfiguration capability of our RMON agent system, a simple port scanning attack detection module is added to the RMON agent system. We have also evaluated the performance of our RMON agent system on a large network that has a huge traffic. The test result has shown our RMON agent system can analyze the network packets without packet loss.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.11a
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• pp.765-768
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• 2004

IEEE 802.110e는 실시간 트래픽의 QoS를 보장하기 위해 제안되었으나 cellular ip network 망에서 발생하는 route update packet과 같은 signaling traffic에 대해서는 아무런 언급을 하고 있지 않다. 따라서 본 논문에서는 IEEE 802.11e draft가 제안하고 있는 4가지의 AC(Access Category)에 따라 signaling traffic 에 대해서도 높은 우선 순위를 할당 함으로서 handoff시 발생하는 packet drop 이 얼마 만큼 줄어드는지를 분석하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.477-478
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• 2009

안정적이고 원활한 네트워크 환경을 구축하기 위해서는 응용 트래픽 분류가 필수적이다. 하지만, 트래픽 분류 방법론들은 새로운 응용의 등장이나 기존 응용의 변화 때문에 네트워크의 모든 트래픽을 분류하지 못한다. 본 논문에서는 이러한 미확인 트래픽을 분석하여 어떤 응용인지 파악함으로써 트래픽 분석률을 향상시키는 방법을 제안한다. 미확인 트래픽을 동일한 특징을 가지는 그룹으로 그룹핑하는 그룹핑 알고리즘과 생성된 그룹으로부터 응용을 찾는 방법을 제시한다.

• Journal of Information Processing Systems
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• v.10 no.1
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• pp.103-118
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• 2014

Over the last couple of years, traditional VANET (Vehicular Ad Hoc NETwork) evolved into VANET-based clouds. From the VANET standpoint, applications became richer by virtue of the boom in automotive telematics and infotainment technologies. Nevertheless, the research community and industries are concerned about the under-utilization of rich computation, communication, and storage resources in middle and high-end vehicles. This phenomenon became the driving force for the birth of VANET-based clouds. In this paper, we envision a novel application layer of VANET-based clouds based on the cooperation of the moving cars on the road, called CaaS (Cooperation as a Service). CaaS is divided into TIaaS (Traffic Information as a Service), WaaS (Warning as a Service), and IfaaS (Infotainment as a Service). Note, however, that this work focuses only on TIaaS and WaaS. TIaaS provides vehicular nodes, more precisely subscribers, with the fine-grained traffic information constructed by CDM (Cloud Decision Module) as a result of the cooperation of the vehicles on the roads in the form of mobility vectors. On the other hand, WaaS provides subscribers with potential warning messages in case of hazard situations on the road. Communication between the cloud infrastructure and the vehicles is done through GTs (Gateway Terminals), whereas GTs are physically realized through RSUs (Road-Side Units) and vehicles with 4G Internet access. These GTs forward the coarse-grained cooperation from vehicles to cloud and fine-grained traffic information and warnings from cloud to vehicles (subscribers) in a secure, privacy-aware fashion. In our proposed scheme, privacy is conditionally preserved wherein the location and the identity of the cooperators are preserved by leveraging the modified location-based encryption and, in case of any dispute, the node is subject to revocation. To the best of our knowledge, our proposed scheme is the first effort to offshore the extended traffic view construction function and warning messages dissemination function to the cloud.

• Journal of Internet Computing and Services
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• v.12 no.3
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• pp.89-99
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• 2011

The payload signature-based traffic classification system has to deal with large amount of traffic data, as the number of internet-based applications and network traffic continue to grow. While a number of pattern-matching algorithms have been proposed to improve processing speedin the literature, the performance of pattern matching algorithms is restrictive and depends on the features of its input data. In this paper, we studied how to optimize the search space in order to improve the processing speed of the payload signature-based traffic classification system. Also, the feasibility of our design choices was proved via experimental evaluation on our campus traffic trace.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.4 s.34
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• pp.3-9
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• 2005

The extraction of traffic information based on image processing is under broad research recently because the method based on image processing takes less cost and effort than the traditional method based on physical equipment. The main purpose of the algorithm based on image processing is to extract vehicles from an image correctly. Before the extraction, the algorithm needs the pre-processing such as background subtraction and binary image thresholding. During the pre-processing much noise is brought about because roadside tree and passengers in the sidewalk as well as vehicles are extracted as traffic flow. The noise undermines the overall accuracy of the algorithm. In this research, most of the noise could be removed by extracting the exact road area which does not include sidewalk or roadside tree. To extract the exact road area, traffic lanes in the image were used. Algorithm speed also increased. In addition, with the ratio between the sequential images, the problem caused by vehicles' shadow was minimized.

• Journal of Information Processing Systems
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• v.12 no.2
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• pp.183-195
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• 2016

This paper presents a complete method for vehicle detection and tracking in a fixed setting based on computer vision. Vehicle detection is performed based on Scale Invariant Feature Transform (SIFT) feature matching. With SIFT feature detection and matching, the geometrical relations between the two images is estimated. Then, the previous image is aligned with the current image so that moving vehicles can be detected by analyzing the difference image of the two aligned images. Vehicle tracking is also performed based on SIFT feature matching. For the decreasing of time consumption and maintaining higher tracking accuracy, the detected candidate vehicle in the current image is matched with the vehicle sample in the tracking sample set, which contains all of the detected vehicles in previous images. Most remarkably, the management of vehicle entries and exits is realized based on SIFT feature matching with an efficient update mechanism of the tracking sample set. This entire method is proposed for highway traffic environment where there are no non-automotive vehicles or pedestrians, as these would interfere with the results.

• Journal of Information Processing Systems
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• v.6 no.2
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• pp.147-162
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• 2010

In this paper, we present a fine-grained localization algorithm for wireless sensor networks using a mobile beacon node. The algorithm is based on distance measurement using RSSI. The beacon node is equipped with a GPS sender and RF (radio frequency) transmitter. Each stationary sensor node is equipped with a RF. The beacon node periodically broadcasts its location information, and stationary sensor nodes perceive their positions as beacon points. A sensor node's location is computed by measuring the distance to the beacon point using RSSI. Our proposed localization scheme is evaluated using OPNET 8.1 and compared with Ssu's and Yu's localization schemes. The results show that our localization scheme outperforms the other two schemes in terms of energy efficiency (overhead) and accuracy.

• The Journal of Information Systems
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• v.14 no.3
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• pp.97-104
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• 2005

The paper proposes an implementation architecture of DiffServ-over-MPLS traffic engineering (TE) on Intel IXP2400 network processor using Intel IXA SDK 4.0 Framework. Program architecture and functions are described. Also fast and scalable range-match classification scheme is proposed for DiffServ-over-MPLS TE that has been integrated with functional blocks from Intel Microblocks library. Performance test shows that application can process packets at approximate data rate of 3.5 Gbps. The proposed implementation architecture of DiffServ-over-MPLS TE on Network processor can provide guaranteed QoS on high-speed next generation Internet, while being flexible and easily modifiable.

• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.788-798
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• 2000

We can consider the interconnection structure suing WDM from two different levels, physical and virtual topologies. In the virtual topology, various channels on physical links can be established between transmitters and the receivers of the nodes. It is important to design efficient virtual topologies, because they have a benefit of performance improvement in interconnection networks depending on traffic matrices without changing physical topologies. In this paper we suggest a way to design virtual topologies that minimize average packet delays for given traffic matrices using genetic algorithms.