• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.295-306
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• 2008

The Intersection is inner traffic facilities and the space where the roads are intersected and connected. And also, the Intersection is the decision-making section for drivers to select the route according to the geometric structure and operation method. However decision-making section cause to raise car accidents rate because it imposes a heavy burden on drivers. In that reason, many countries such as Europe use the Roundabouts to reduce the numbers of decision making and collision. In Korea, the kinds of method are just introduced and it is using now but there are no exact standards. Hence, this study suggests the process to evaluate and determine the types of Intersection which are based on the traffic flow (congestion) and traffic safety (accidents). Firstly, this study presents the number of accident at each Intersection which is depended on the traffic volume. Secondly, this study calculates and analysis the accident at signalized Intersection, non-signalized Intersection and Roundabout by TSIS-NETSIM program. Thirdly, this study concludes the best suitable Intersection type through the materials which are mentioned before.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.47-53
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• 1987

Many studies are conducted to evaluate the risk of maneuvering ships in the congested harbours and narrow channels. These studies are very important for the prevention of sea traffic accidents in those sea areas. In this paper, the author carried out a series of observations on sea traffic condition of the vessels entering and leaving the harbour of CHUNG MU, in order to evaluate the risk of grounding, the margin and burden of route keeping maneuver of vessels proceeding along the fairway of this harbour. The results obtained are as follows: 1. The grounding risk indices for the east bound and west bound vessels at the middle part and western part of the fairway were higher than those of them at the eastern part. 2. The margin of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for the east bound vessels, and the highest at the middle part for the west bound vessels, but the lowest at the western entrance for both of them. 3. The burden of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for both of the east bound and west bound vessels, but the lowest at the eastern part for both of them. 4. The influence of maneuvering indices T' on the grounding risk indices appeared to be larger than that of maneuvering indices K' on them.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.2
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• pp.1-1
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• 1987

Many studies are conducted to evaluate the risk of maneuvering ships in the congested harbours and narrow channels. These studies are very important for the prevention of sea traffic accidents in those sea areas. In this paper, the author carried out a series of observations on sea traffic condition of the vessels entering and leaving the harbour of CHUNG MU, in order to evaluate the risk of grounding, the margin and burden of route keeping maneuver of vessels proceeding along the fairway of this harbour. The results obtained are as follows: 1. The grounding risk indices for the east bound and west bound vessels at the middle part and western part of the fairway were higher than those of them at the eastern part. 2. The margin of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for the east bound vessels, and the highest at the middle part for the west bound vessels, but the lowest at the western entrance for both of them. 3. The burden of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for both of the east bound and west bound vessels, but the lowest at the eastern part for both of them. 4. The influence of maneuvering indices T' on the grounding risk indices appeared to be larger than that of maneuvering indices K' on them.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.30-40
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• 2010

The freeway congestion is largely generated by a mainline spillover of the exit ramp queue. So it is necessary to study for modeling of the phenomenon and applying the model. In this study, the authors evaluated applicability of the Supply-Demand model, which can express traffic flow for the freeway by applying flexibly supply and demand curves for capacity of the freeway. First the authors proposed methods processing input data required in the Supply-Demand model, such as sending & receiving functions and time-varying capacity constraints for the freeway mainline. After modeling the Supply-Demand application model, the authors applied the model to the site including congested Hongeun exit ramp in Seoul Ring-road, and improved the model by adjusting application techniques and calibrating parameters. The result of the analysis showed that the Supply-Demand model yielded a queuing pattern and queue location similar to them observed in the field data, and applicability of the Supply-Demand model was varified.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.167-176
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• 2004

The authors have newly developed the “Port Traffic Management System (PTMS)”. The PTMS provides each ship with the detailed planned routes of all the ships entering/leaving the port. This system also has a function to predict the encounter situations between own ship and other ships in the future. Based on information of the present positions, speeds and planned routes of the own ship and other ships, it is possible to predict when and where the own ship will have dangerous encounters with other ships in the future. The software of PTMS was developed from 2001. Then onboard experiments using small training ships equipped with actual AIS were performed in June 2003. From the results of these onboard experiments, the usefulness of PTMS was clarified. In addition to these onboard experiments, the effectiveness of PTMS was confirmed by comprehensive simulator experiments. In the simulator experiments, captains/pilot maneuvered a training ship/container ship in congested waters using PTMS. [t was assumed that all ships have PTMS and send their planned routes. After the simulator experiments, captains/pilot suggested that it is very beneficial if the optimal route of own ship can be automatically calculated. In response to this suggestion, software to calculate the optimal route of own ship using Dynamic Programming was developed. This software calculates the minimum time route from the present position to the destination keeping the danger of collision against other ships under predetermined level. From the result of calculations for multi-encounter situations, it was confirmed that the developed software can provide safe and time-saving route.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2003.05a
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• pp.8-13
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• 2003

Historically, IP-based internets have been able to provide a simple best-effort delivery service to all applications they carry. Best effort treats all packets equally, with no service level, packet loss, and delay. But the needs of users have changed. The want to use the new real-time, multimedia, and multicasting applications. Thus, there is a strong need to be able to support a variety of traffic with a variety of quality-of-service requirements. The DiffServ architecture, proposed by the Internet Engineering Task Force(IETF), has become the most viable solution for provising QoS over IP networks. The DiffServ architecture does not specify any handling method between AF out-profile packets and BE packets. This paper propose a mechanism for supporting inter class fairness in the DiffServ architecture. Ⅰ proposed a modified Weighted Round Robin method to protect the BE traffic from AF out-profile packets in the core routers. The proposed technique is evaluated through simulation. Simulation results indicate that the proposed method provides better protection not only for BE packets from AF out-profile packets, but also for the AF in-profile packets in congested networks.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1043-1048
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• 2017

Since year 2016, in Korea, the police department started to use drones to patrol violated vehicles on the highway area. They monitor vehicle drivers who use side ways on the highway during traffic congested hours of the season, drunken drivers, or violent drivers. They use the 'Spot Mobility' method which floats the drones for 30 minute period. However, this method is inefficient since it requires manually charging batteries, gathering data, and operate drones with many numbers of policeman. Therefore, in this paper, for the efficient patrol in this purpose, I have suggested an effectively manageable network system consists of many drones as the wireless network nodes and with small numbers of policeman in a wide highway area. To accomplish this, the two topologies of effective drone patrol network systems are designed and simulated in OPNET simulator for performance evaluation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1B
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• pp.1-7
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• 2010

In this paper, a high-performance fault-tolerant switching network using a deflection self-routing was proposed. From an abstract algebraic analysis of the topological properties of the Delta network, which is a baseline switching network, we derive the Multidimensional Ring-Delta network: a multipath switching network using a deflection self-routing algorithm. All of the links including already existing links of the Delta network are used to provide the alternate paths detouring faulty/congested links. We ran a simulation analysis under the traffic loads having the non-uniform address distributions that are usual in Internet. The throughput of $1024\;{\times}\;1024$ switching network proposed is better than that of the 2D ring-Banyan network by 13.3 %, when the input traffic load is 1.0 and the hot ratio is 0.9. The reliability of $64\;{\times}\;64$ switching network proposed is better than that of the 2D ring-Banyan network by 46.6%.

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.2
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• pp.99-102
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• 2012

The performance of P2P application services may be improved by reducing unnecessary inter-network traffic through intelligent peer selection. However, since a logical link between peers in a P2P overlay network is composed of a set of physical links in an underlay network, the traffic pattern determined by the sending rates of selected peers imposes loads on each underlay links. Thus, if the sending rates are not determined carefully, the loads between underlay links may not be balanced, which means some links are underloaded while the other links are congested. In this paper, we take an optimization approach to determine the sending rates of peers strategically to avoid the inefficient use of underlay links. The proposed scheme also guarantee the minimum receiving rates of peers while minimizing the maximum link utilization of underlay links, which is beneficial both to P2P applications and an underlay network.

• Journal of the Korea Society of Computer and Information
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• v.28 no.5
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• pp.9-15
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• 2023

In this paper, we propose a method predicting the speed of each lane from the link speed using a neural network. We took three measures for configuring learning data to increase prediction accuracy. The first one is to expand the spatial range of the data source by including 14 links connected to the beginning and end points of the link. We also increased the time interval from 07:00 to 22:00 and included the data generation time in the feature data. Finally, we marked weekdays and holidays. Results of experiments showed that the speed error was reduced by 21.9% from 6.4 km/h to 5.0 km/h for straight lane, by 12.9% from 8.5 km/h to 7.4 km/h for right turns, and by 5.7% from 8.7 km/h to 8.2 km/h for left-turns. As a secondary result, we confirmed that the prediction accuracy of each lane was high for city roads when the traffic flow was congested. The feature of the proposed method is that it predicts traffic conditions for each lane improving the accuracy of prediction.