• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.6
• /
• pp.642-648
• /
• 2019

Vessels sail according to the COLREG to prevent a collision. However, it is difficult to apply COLREG under special situation as heavy traffic, at this time personal skills of the operator are required. In this case, traffic control is required through the maritime traffic monitoring system. Therefore, maritime traffic management is globally implemented by VTS. In this system, VTS of icer uses the VTS system to assess risks and recommends possible safety operation to vessels with radio systems. This study considers that the risk analysis method with AI (Artificial Intelligence) technology from the operator's aspect. In addition, the research explains the Maritime Traffic Safety Monitoring System, Including AR (Augmented Reality) technology to increase vessel control efficiency. This system is able to predict hazards and risk priorities, and it leads to sequential elimination of dangerous situations. Especially, the hazard situations can be analyzed from operator's perspective of each vessel instead of the VTS officer's aspect, which is more practical than the conventional method. Furthermore, the result of analysis enables to comprehend quantitative hazardous areas and support recommended routes to avoid a collision. As a result, I firmly believe that the system will support to prevent a collision in complex traffic waters. In particular, it could be adopted as a collision prevention system for Maritime Autonomous Surface Ship, which occupies a significant proportion in Maritime 4th industrial revolution.

• Journal of the Korea Computer Industry Society
• /
• v.3 no.5
• /
• pp.631-640
• /
• 2002

The internet phones that are currently available in use adopt packet exchange system, transferring through various routes and lacking sufficient band width with a result that there is an accompanied delay for packet transmission since the traffic is increased, accordingly affecting a lot in sound quality and speed. Two solutions for such troubles are suggested in this study to improve sound quality of internet phones. Firstly, we minimize the delay and damage regarding packet size based on traffic size by using the data algorithm from variable packets in order to supplement decreased sound quality due to the delay and damage of sound data. The second suggestion is to employ a method of Jitter compensation by giving an appropriate initial delay time with regenerating buffers to bypass troubles from Jitter, From employing the Jitter compensation method, we found that there is a sound quality improvement due to the less stoppage phenomenon.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2005.10a
• /
• pp.388-393
• /
• 2005

Private peering, public peering and transit are three common types of interconnection agreements between providers in the Internet. An important decision that an Internet service provider (ISP) has to make is which private peering/transit ISPs and Internet exchanges (IXs) to connect with to transfer traffic at a minimal cost. In this paper, we deal with the problem to find the minimum cost set of private peering/transit ISPs and IXs for a single ISP. There are given a set of destinations with traffic demands, and a set of potential private peering/transit ISPs and IXs with routing information (routes per destination, the average AS-hop count to each destination, etc.), cost functions and capacities. Our study first considers all the three interconnection types commonly used in real world practices. We show that the problem is NP-hard, and propose a heuristic algorithm for it. We then evaluate the quality of the heuristic solutions for a set of test instances via comparison with the optimal ones obtained by solving a mixed integer programming formulation of the problem. Computational results show that the proposed algorithm provides near-optimal solutions in a fast time.

• Spatial Information Research
• /
• v.8 no.1
• /
• pp.117-130
• /
• 2000

This paper presents a GIS-based method of spatial analysis that can be applied to the line determination in traffic infrastructure project . It is based on the spatial analysis of the sensitivity or suitability of areas relating to the integration of new infrastructure routes, carefully considering the requirement of intervention optimizing . It makes the comparison of alternatives and a final selection of a"best route " easier, offers new possibilities and simplifies and accelerates the whole process of line determination. The developed method for route-alignment is tried out by an example project for road planing in Germany. It point out that during the line determination all aspects can be equivalently and adequately evaluated. So this method is well suited as a new tool within a line determination procedure and can bring enormous advantages in the planning process of traffic infrastructure projects. projects.

• Land and Housing Review
• /
• v.2 no.3
• /
• pp.217-226
• /
• 2011

The Seoul Metropolitan Government is striving to minimize the amount of traffic according to the supply of apartment houses along with the solution of housing shortage for the low income people through high density development near the subway area. Therefore, a stronger policy is necessary to control the traffic of the passenger cars in a subway area for the successful high density development focusing on public transportation, and especially, the estimation of the demand of cars with high reliability is necessary to control the demand of parking such as the limited supply of parking lot. Accordingly, this study developed car ownership forecasting model using Look-up Table among category analyses which are easy to be applied and have high reliability. The estimation method using Look-up-Table is possible to be applied to both measurable and immeasurable types, easy to accumulate data, and features the flexible responding depending on the changes of conditions. This study established Look-up-Table model through the survey of geographical location, the scale of housing, the accessible distance to a subway station and to a bus station, the number of bus routes, and the number of car owned with data regarding 242 blocks in Seoul City as subjects.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.12
• /
• pp.5286-5306
• /
• 2016

Emerging applications in automation, medical imaging, traffic monitoring and surveillance need real-time data transmission over Wireless Sensor Networks (WSNs). Guaranteeing Quality of Service (QoS) for real-time traffic over WSNs creates new challenges. Rapid penetration of smart devices, standardization of Machine Type Communications (MTC) in next generation 5G wireless networks have added new dimensions in these challenges. In order to satisfy such precise QoS constraints, in this paper, we propose a new cross-layer QoS-provisioning strategy in Wireless Multimedia Sensor Networks (WMSNs). The network layer performs statistical estimation of sensory QoS parameters. Identifying QoS-routing problem with multiple objectives as NP-complete, it discovers near-optimal QoS-routes by using evolutionary genetic algorithms. Subsequently, the Medium Access Control (MAC) layer classifies the packets, automatically adapts the contention window, based on QoS requirements and transmits the data by using routing information obtained by the network layer. Performance analysis is carried out to get an estimate of the overall system. Through the simulation results, it is manifested that the proposed strategy is able to achieve better throughput and significant lower delay, at the expense of negligible energy consumption, in comparison to existing WMSN QoS protocols.

• ETRI Journal
• /
• v.32 no.3
• /
• pp.430-439
• /
• 2010

Inundation of roads by heavy rainfall has attracted more attention than traffic accidents, traffic congestion, and construction because it simultaneously causes travel delays and threatens driver safety. For these reasons, in this paper, we propose an inundation hazard index (IHI) of road links, which shows the possibility of inundation of road links caused by rainfall. To generate the index, we have used two key data sources, namely the digital elevation model (DEM) and past rainfall records of when inundation has occurred. IHI is derived by statistically analyzing the relationships between the normalized relative height of the road links calculated from DEM within the watershed and past rainfall records. After analyzing the practical applicability of the proposed index with a commercial car navigation system through a set of tests, we confirmed that the proposed IHI could be implemented to choose safer routes, with reduced chances of encountering roads having inundation risks.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.12
• /
• pp.2635-2643
• /
• 1997

In this paepr, a routing algorithm is proposed in order to reduce average end-to-end delay and congesting in the high speed network. The algorithm proposed here uses the existing one which adaptively modifies routes and the amount of traffic allocated to each link as user traffic partterns flutuate. This algorithm is ELB(Equitable Load Balancing). Also, the new algorithm considers the proportional to the distance between source and destination. It reduces congestion from the ELB and average end-to-end delay from the propagation dealy concepts respectively. Through the simulation, it shows that the algorithm proposed here reduces average end-to-end delay over low load to high load, and it also guarantees the congestion control.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.1
• /
• pp.30-35
• /
• 2002

Dynamic routing uses routing protocols to select the best routes and to update the routing table. RP (Routing Information Protocol)using a distance-vector algorithm becomes generally known a routing protocol on the network. RIP selects the route with the lowest "hop count" (metric) as the best route. but RIP has a serious shortcoming. a mP router cannot maintain a complete routing table for a network that has destinations more than 15 hops away. To overcome this defect, It uses the OSPF (Open Shortest Path First) of link -state protocols developed for TCP/IP. It is suitable for very large networks and provides several advantages over RIP. This paper analyzes the traffic and the link efficiency between two protocols such as message delivery and delay, link utilization, message counts on the same network.e network.

• International Journal of Highway Engineering
• /
• v.15 no.5
• /
• pp.135-144
• /
• 2013

PURPOSES : The purpose of this paper is to develop a methodology to estimate level of service of arterial including Exclusive Median Bus Lanes. METHODS : On 6 Exclusive Median Bus Lanes routes in Seoul, bus travel time and number of bus-stop per km were investigated. Also whether or not passing lane exists at bus-stop was checked. Based on the data from sites, bus travel time was estimated according to length of segment, number of bus-stop per km and whether or not passing lane exists at bus-stop. RESULTS : A bus travel time table was developed according to length of segment, number of bus-stop per km and whether or not passing lane exists at bus-stop. After bus travel speed and passenger car travel speed is estimated based on each travel time table and length of segment, two speeds are combined with weighted average speed using traffic volume of each lane group. Then weighted average speed is a measure of effectiveness of arterial including Exclusive Median Bus Lanes. CONCLUSIONS : It can be concluded that the proposed methodology can estimate level of service of arterial including Exclusive Median Bus Lanes considering the operation characteristics of Exclusive Median Bus Lanes.