• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2736-2739
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• 2002

This paper is a study on the railway traffic conflict resolution(RTCR) using genetic algorithm(GA). Using GA, many complicated problems can be expressed in the easy way, and good solutions can be found in a reasonably short time. Due to the above merits, we focus to GA first of all. We express the sample RTCR problem and algorithm of Korean railroad using GA. From the Mark Ho's[2,3] results, we introduce a chromosome scheme in addition.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.88-91
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• 2000

In this paper we approach the problem of congestion control for TCP traffic over ATM-UBR networks by focusing on the fact that to get best performance. We study how to efficiently support TCP traffic in the subnet ATM model, when ATM is only a single link in the whole path. We show that when UBR connection. We analyze the ATM-UBR network service using the BSD 4.3 Reno, Tahoe TCP. However we found the fact that the characteristic of fast recovery algorithm makes a serious degradation of performance in multiple cell loss drop situation. We propose new fast recovery algorithm to solve the problem.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.253-265
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• 2010

The problem of pricing for a telecommunication network is investigated with respect to the users' sensitivity to the pricing structure. A functional optimization problem is formulated, in order to compute price reallocations as functions of data collected in real time during the network evolution. No a-priori knowledge about the users' utility functions and the traffic demands is required, since adaptive reactions to the network conditions are sought in real time. To this aim, a neural approximation technique is studied to exploit an optimal pricing control law, able to counteract traffic changes with a small on-line computational effort. Owing to the generality of the mathematical framework under investigation, our control methodology can be generalized for other decision variables and cost functionals.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.2
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• pp.236-247
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• 2002

We propose a cell－multiplexing scheme for the real－time communication service in ATM network and a new service discipline guarantee end-to-end delay based on pseudo-isochronous cell switching. The proposed scheme consists of two level frame hierarchy, upper and lower frame, which is used to assign the bandwidth and to guarantee the requested delay bound, respectively. Since the Proposed algorithm employs two level frame hierarchy, it can overcome the coupling problem which is inherent to the framing strategy It can be comparatively reduce the complexity, and still guarantee the diverse delay bounds of end-to-end. Besides, it consists of two components, traffic controller and scheduller, as the imput traffic description model and regulates the input traffic specification. The function of the traffic controller is to shape real -time traffic to have the same input pattern at every switch along the path. The end-to-end delay is bounded by the scheduller which can limit the delay variation without using per-session jitter controllers, and therefore it can decrease the required buffer size. The proposed algorithm can support the QoS's of non-real time traffic as well as those of real time traffic.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.172-181
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• 2005

The latest attack type against network traffic appeared by worm and bot that are advanced in DDoS. It is difficult to detect them because they are diversified, intelligent, concealed and automated. The exisiting traffic analysis method using SNMP has a vulnerable problem; it considers normal P2P and other application program to be harmful traffic. It also has limitation that does not analyze advanced programs such as worm and bot to harmful traffic. Therefore, we analyzed harmful traffic out Protocol and Port analysis. We also classified traffic by protocol, well-known port, P2P port, existing attack port, and specification port, apply singularity weight to detect, and analyze attack availability. As a result of simulation, it is proved that it can effectively detect P2P application, worm, bot, and DDoS attack.

• Journal of Korean Society of Transportation
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• v.33 no.1
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• pp.70-80
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• 2015

In recent years, tram has been the focus of a new mode of public transportation that can solve traffic jams and decrease public transit usage and environmental problem. This research is in the works to develop a tram signal controller and signal control strategies, and aim to resolve the problem of what could happen if a tram system was installed in general road. We developed the hierarchical signal control strategies to obtain a minimum tram bandwidth and to minimize vehicle delay, in order to perform a priority control to include passive and active signal priority control strategies. The strategies was produced for S/W and H/W, it is based in standard traffic signal controller. We conducted a micro simulation test to evaluate the hierarchical signal control strategies, which showed that the developed optimization model is effective to prevent a tram's stop in intersection, to reduce a tram's travel time and vehicle's delay.

• Journal of Advanced Navigation Technology
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• v.11 no.3
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• pp.306-312
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• 2007

Present TCP/IP networks have some service quality problems. They delay various kinds of traffic, while increased traffic bottle necks, a phenomena experienced by too many internet users. Therefore, as use of the network increases, building up a stable network service is needed. Thus, network managers desperately need the best, most effective traffic control and wide-band services. Until now there has been no other way of increasing wide-band use of lines, particularly because of the expenses a limit solutions of solving continuously to increasing traffic problems. This study suggests a problem solving method under the base of 802.16e(Wibro) which will be widely used in the future.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.284-290
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• 2015

Road traffic noise is closely related with urban forms and urban components, such as population, building, traffic and land-use, etc. Hence, it is possible to minimize the noise exposure problem depending on how to plan new town or urban planning alteration. This paper provides ways to apply for urban planning in consideration of noise exposure through road traffic noise estimation for alteration of small-scale urban form. Spatial autoregressive model from the former study is used as statistical model for noise simulation. The simulation results by the spatial statistical model are compared with those by the engineering program-based modeling for 5 scenarios of small-scale urban form alteration. The error from the limitation of containing informations inside the grid cell and the difficulties of reflecting acoustic phenomena exists. Nevertheless, in the stage of preliminary design, the use of the statistical models that have been estimated well could be useful in time and economically.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.3
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• pp.677-689
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• 2013

Recently, the supplying of basic materials for construction of building as sand is big issues due to lack of shoreside supply. For solving this problem, many suppliers attempt to gather aggregate from the sea bottom of the EEZ & west coastal area of Korea. In this regard, the 'Jangantoe' which exists in the westside of the Daesan port is worth noticing as good seasand supplying areas. The Chungnam Aggregate Association have plan to gather of seasand from 'Gaduckdo 5 regions & Igok 3 regions' which lies westside about 6 miles off from the Jangantoe areas. This designated area also locates upper parts of the Gadaeam TSS(Traffic Separation Scheme) which is very useful passing routes for the sailing vessels of Inchon & Daesan ports. In this study, the evaluation of the safety for passing vessels in the vicinity of the seasand gathering area was performed by various methods of radar observations & GICOMS AIS data for marine traffics and vessel traffic-flow simulation of the 'Marine Traffic Safety Diagnostic Scheme'. By the results of this evaluation, I suggested comprehensive countermeasures for the safety of passing vessels in the near the seasand gathering area.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.2
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• pp.123-128
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• 2002

A fuzzy traffic controller with the control rules and the membership functions generated by using genetic algorithm is presented for crossroad management. Conventional fuzzy traffic controllers use control rules and membership functions generated by human operators. However, this approach does not guarantee the optimal solution to design fuzzy control system. Genetic algorithm is a good solution for an optimal problem requiring domain-specific knowledge that is often heuristic. In this paper, we use genetic algorithms to automatically determine the near optimal rules and their membership functions of fuzzy traffic controllers. The effectiveness of our method was shown through simulation of crossroad network.