• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.5
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• pp.162-177
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• 2020

The perception of traffic environment based on various sensors in autonomous driving system has a direct relationship with driving safety. Recently, as the perception model based on deep neural network is used due to the development of machine learning/in-depth neural network technology, a the perception model training and high quality of a training dataset are required. However, there are several realistic difficulties to collect data on all situations that may occur in self-driving. The performance of the perception model may be deteriorated due to the difference between the overseas and domestic traffic environments, and data on bad weather where the sensors can not operate normally can not guarantee the qualitative part. Therefore, it is necessary to build a virtual road environment in the simulator rather than the actual road to collect the traning data. In this paper, a training dataset collection process is suggested by diversifying the weather, illumination, sensor position, type and counts of vehicles in the simulator environment that simulates the domestic road situation according to the domestic situation. In order to achieve better performance, the authors changed the domain of image to be closer to due diligence and diversified. And the performance evaluation was conducted on the test data collected in the actual road environment, and the performance was similar to that of the model learned only by the actual environmental data.

• Convergence Security Journal
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• v.22 no.4
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• pp.65-73
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• 2022

Since cyber operations are performed in a virtual cyber battlefield, the measurement indicators that can evaluate and visualize the current state of the cyber environment in a consistent form are required for the commander to effectively support the decision-making of cyber operations. In this paper, we propose a method to define various evaluation indicators that can be collected on the cyber battlefield, normalized them, and evaluate the cyber status in a consistent form. The proposed cyber battlefield status element consists of cyber asset-related indicators, target network-related indicators, and cyber threat-related indicators. Each indicator has 6 sub-indicators and can be used by assigning weights according to the commander's interests. The overall status of the cyber battlefield can be easily recognized because the measured indicators are visualized in time series on a single screen. Therefore, the proposed method can be used for the situational awareness required to effectively conduct cyber warfare.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.185-185
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• 2022

상수도 관망의 운영 단계에서 비정상상황의 발생은 필연적으로 발생하며, 비정상상황 발생 시상수도 관망 내 설치된 제수 밸브의 차폐를 통해 해당 구역의 격리 후 복구를 진행한다. 일반적으로 제수밸브를 통해 격리될 수 있는 최소 구역은 세그먼트로 정의하고, 제수밸브 설치 시 세그먼트의 격리로 인한 상수도 관망의 피해를 줄일 수 있도록 위치를 선정한다. 제수 밸브를 통한 격리 시 상수도 관망의 흐름 경로와 유향, 유속의 변화와 같은 수리적 특성 변화가 불가피하다. 지난 '19년도에 발생했던 3건의 수질 사고가 수리적 특성 변화에서 기인했던 것을 고려할 때, 제수밸브 차폐로 상수도 관망의 부분 격리 시 발생 가능한 수리적 특성 변화에서도 수질 사고가 야기될 가능성이 있다. 기존 제수밸브 위치를 결정한 연구들을 보면, 대부분 제수밸브 위치에 따라 결정된 세그먼트의 격리 시 수압 저감을 고려하여, 격리 시에도 상수도 관망의 성능을 최대한 유지할 수 있도록 결정하는 것이 일반적이다. 다만, 앞서 언급한 것과 같이 격리 시 발생 가능한 수리적 특성 변화로, 수압 저감 외에도 예기치 못한 수질 사고의 발생 원인이 되기도 한다. 이에 따라 제수밸브의 최적위치를 결정할 때 수리적 특성 변화를 고려해야 예지치 못한 2차 피해를 줄일 수 있을 것이다. 이에 본 연구는 그래프이론을 활용하여 격리 전후 관로의 유향 변화를 최소화하도록 제수밸브 최적 위치 결정하는 방법론을 제안한다. 그래프이론은 망의 형태를 가지는 상수도 관망의 연결성을 정량화할 수 있으며, 본 연구에서는 수리학적 거리 인자를 적용하여 격리 시에도 각 수요절점이 최소 경로를 확보할 수 있도록 유도하였다. 해당 방법론은 가상 관망에 적용하여 수리학적 거리 인자에 따른 설계와 기존 상수도 관망 성능 극대화 설계 안을 비교하였다. 또한 수질 사고 위험도 인자를 정의하여 해당 인자에 따른 각 설계 안의 효과를 분석하였다. 본 연구는 향후 수질 사고를 고려한 밸브 시스템의 설계 및 운영에 활용할 수 있을 것으로 기대한다.

• Journal of Digital Contents Society
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• v.14 no.4
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• pp.557-564
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• 2013

An important research challenge about the traditional Internet environment is to enable open networking architecture on which end users are able to innovate the Internet based on the technologies of network programmability, virtualization, and federation. The SDN (Software Defined Network) technology that includes OpenFlow protocol specifications, is suggested as a major driver for the open networking architecture, and is closely coupled with the classical Internet (non-SDN). Therefore, it is very important to keep the integrated SDN and non-SDN network infrastructure reliable from the view point of network operators and engineers. Under this background, this paper proposes an operations and management framework for the combined software defined network environment across not only a single-domain network, but also multi-domain networks. The suggested framework is designed to allow SDN controllers and DvNOC systems to interact with each other to achieve sustainable end-to-end user-oriented SDN and non-SDN integrated network environment. Plus, the proposed scheme is designed to apply enhanced functionalities on DvNOC to support four major network failure scenarios over the combined network infrastructure, mainly derived from SDN controllers, SDN devices, and the connected network paths.

• The Journal of Society for e-Business Studies
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• v.20 no.4
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• pp.1-17
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• 2015

A river water level monitoring system which prevents salt water damages and effectively excludes floods has been developed to contribute efficient operation of Nakdong river estuary barrage. The system can be used for monitoring upstream conditions more quickly and do appropriate responses over changes. Telemetry and telecontrols using PLCs have been built at the three sites that directly influence on the operation of barrage gates, and are linked to Nakdong river estuary barrage's IOS (Integrated Operation System) through public communication networks. By using PLC, the system can achieve even higher reliability and versatility than before as well as easy management. By power control devices, we can remotely control the power of PLCs to treat the minor troubles instantly without going on-sites. The power control devices also save data in preparation for the cases of communication failures. The system uses ADSL (FTTH) as a main network between SCADA server and PLCs, and CDMA (M2M) as a secondary network. In order to compensate security vulnerabilities of public communication network, we have installed the VPNs for secure communication between center and the observation stations, just like a dedicated network. Generally, river water level observations have been used custom-manufactured remote terminals to suit their special goals. However, in this case, we have established a system with open architecture considering the interface between different systems, the ease of use and maintenance, security, price, etc.

• Journal of KIISE:Information Networking
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• v.33 no.3
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• pp.247-256
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• 2006

Among the resource provisioning mechanisms for the hose based Virtual Private Network (VPN) Quality of Service (QoS ), VPN-specific state provisioning allows the service provider to obtain highest resource multiplexing gains. However, dynamic and automatic resource reservation for the VPN-specific state provisioning is difficult due to the lack of appropriate resource reservation protocol. Furthermore, users of a VPN may experience unfair usage of resources among themselves since the reserved resources of a VPN are shared by the VPN users in a similar way that the traditional LAN bandwidth is shared by the attached hosts. In this paper, we propose a resource reservation protocol and a traffic service mechanism, which not only enable dynamic and automatic resource reservation according to the VPN-specific state provisioning algorithm, but also enforce the fair usage of reserved resources among the users of a VPN in case of congestion.

• Journal of Korean Society of Transportation
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• v.20 no.1
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• pp.65-76
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• 2002

This study is realized using fuzzy evaluation and AHP(the analytic hierarchy process) for the optimum search of traffic route and estimated by the quantitative analysis in the vague subjective judgement. It is different from classical route search and noticed thinking method of human. Appraisal element, weight, appraisal value of route is extracted from basic of the opinion gathering fur the driving expert and example of route model was used for the finding of practice utility. Model assessment was performed attribute membership function making of estimate element, estimate value setting, weight define by the AHP, non additive presentation of weight according to $\lambda$-fuzzy measure, Choquet fuzzy integral.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.195-207
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• 2007

The urban railways connecting between the inner city and suburb of Seoul metropolitan area, has lost the competitiveness against cars because too many stops deteriorated operating speed and passenger's level of service. This paper suggests that an express train should be introduced into the urban railway system in order to sort out such a complication. There are two considerations in the present study. Firstly, train schedule problem should be taken into account. In this regard, a new model for urban railway system was developed by revising the existing models dealing with single line freight railway. Approximate branch and bound algorithm based on conflict group rather than a single conflict was adopted. Consequently, it was found that the time saving in calculating the optimal schedule is the most meaningful contribution of the algorithm. The second consideration is associated with the application of the model. A case study was carried out using the actual operation data from Ansan line. In conclusion, the operation speed of the line can increase considerably with minimal number of new sidings.

• Convergence Security Journal
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• v.5 no.2
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• pp.51-56
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• 2005

Service operating management to keep stable and effective environment according as user increase and network environment of the Internet become complex gradually and requirements of offered service and user become various is felt constraint gradually. To solve this problem, invasion confrontation system through proposed this log analysis can be consisted as search of log file that is XML's advantage storing log file by XML form is easy and fast, and can have advantage log files of system analyze unification and manages according to structure anger of data. Also, created log file by Internet Protocol Address sort by do log and by Port number sort do log, invasion type sort log file and comparative analysis created in other invasion feeler system because change sort to various form such as do log by do logarithm, feeler time possible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1471-1477
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• 2003

In order to realize the Gbps VPN system, however, newer and more advanced technologies are required to enable wire-rate processing across a wide range of functions and layers. While it is generally accepted that a software soluTion on general-purpose processors cannot scale to process these functionsa wire rate, the KEY POINT is that a software solution on general-purpose processors is the most practical way by which these security allocationscan be developed. Many of these security functions require application layer processing on the content of the packets, and the very nature of application layer software development is characterized by relatively large code size with a high need for portability an flexibility. We have analysed the consideration and specification for realizing Gbps VPN system. from this work. we can obtain a technology of originality.