• Journal of Korean Society of Transportation
• /
• v.19 no.3
• /
• pp.75-88
• /
• 2001

Signal optimization model for alternative use of lanes at a signalized intersection with an stop-line added backward was presented in this paper. The simulation results shot-ed that the traffic fed from the stop-line passed the intersection in each specified phasing interval for left and through traffic. The experimental results indicated that the proposed model was much superior to traditional signal optimization methodology in reducing delay, fuel consumption, and disutility index for delay and stops. The effects for reducing delay were greater than those for doing fuel consumption and disutility index due to the added stop-line. The proposed model is expected to alleviate traffic congestion at intersections, both which have no left turn pocket, and which have large left turn volume. The model is recommended to adapted for intersections spaced long among them with no near driveway.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.4D
• /
• pp.443-450
• /
• 2009

Uninterrupted facility - since there is a close relationship between traffic volume, speed and density -, when a ramp traffic flow merges into the main line, will change the traffic speed or density, and the corresponding correlational model equation will be changed. Thus, this study, using time and space-series traffic data on areas under the influence of such a merging, identified sections which changed the correlation between speed and density variables, and examined such changes. As a result, the upstream and merging sections showed the "Underwood"-shaped exponent, and the downstream after passing the merging section showed a straight line "Greenshields" model. The downstream section which changed the correlation between speed and density showed a gradual downstream movement phenomenon within 100 m-500 m from the end of the third lane linking with the ramp, as the traffic approached the inner lanes. Also, the upstream section, merging section, and downstream section involving a change showed heterogeneous traffic flows which, in the speed-density model, have a statistically different free flow speed (constant) and a different ratio of free flow speed to jam density (gradient).

• ETRI Journal
• /
• v.30 no.2
• /
• pp.290-300
• /
• 2008

We apply IEEE 802.3 frame burst mode (FBM) to the Ethernet passive optical network (EPON) downstream link and compare its performance with non-frame burst mode for various traffic patterns. Although in light traffic loads (p<0.5) the efficiency of the FBM mechanism is not significant, it does feature high throughput, small jitter, low queue occupancy, and short queuing delay in optical line terminals under various traffic loads with various numbers of optical network units (ONUs). The FBM performance always approaches that of full-duplex mode, especially under heavy traffic loads (p>0.5). Moreover, an increase in number of ONUs will decrease the burst performance. Our work shows that FBM scheme is very useful for EPON transmission and has low design complexity.

• Journal of Navigation and Port Research
• /
• v.34 no.9
• /
• pp.687-692
• /
• 2010

This study is to improve the marine traffic environment along the west coast of the Korean peninsular so as to prevent the traffic accidents of the dangerous cargo carriers. The most used routes of the vessels were investigated from GICOMS database and the questionnaire survey. Gwanjanghang Sudo strait and Maenggol Sudo strait were considered to have some potential risks to the vessels. In this study, the alternative routes were developed to substitute the current routes near Gwanjanghang Sudo strait and the new boundary line of The Traffic Prohibited Area for Tanker was suggested to contain the Maenggol Sudo strait.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.7 no.1
• /
• pp.15-23
• /
• 2003

ATM networks provide the various kinds of service which require the different Quality of Services(QoS) such as loss and delay. By statistically multiplexing of traffics and the uncertainty and fluctuation of source traffic pattern, the congestion may occur. The leaky bucket scheme is a representative policing mechanism for preventive congestion control. In this paper, we analyze the HOL(Head-of-Line) priority leaky bucket scheme. That is, traffics are classified into real-time and nonreal-time traffic. The real-time traffic has priority over nonreal-time traffic for transmission. For proposed mechanism, we obtain the system state distribution, finally the loss probability and the mean waiting time of real-time and nonreal-time traffic. The simple numerical examples also are presented.

• Journal of Intelligence and Information Systems
• /
• v.6 no.1
• /
• pp.113-128
• /
• 2000

This paper presents a first year report of an ongoing multi-year project to develop a systolic parallel simulation system for dynamic traffic assignment. The fundamental approach to the simulation is systolic parallel processing based on autonomous agent modeling. Agents continuously act on their own initiatives and access to database to get the status of the simulation world. Various agents are defined in order to populate the simulation world. In particular existing modls and algorithm were incorporated in designing the behavior of relevant agents such as car-following model headway distribution Frank-Wolf algorithm and so on. Simulation is based on predetermined routes between centroids that are computed off-line by a conventional optimal path-finding algorithm. Iterating the cycles of optimization-then-simulation the proposed system will provide a realistic and valuable traffic assignment. Gangnum-Gu district in Seoul is selected for the target are for the modeling. It is expected that realtime traffic assignment services can be provided on the internet within 3 years.

• Journal of Korean Society of Transportation
• /
• v.5 no.2
• /
• pp.81-95
• /
• 1987

In line with the continued growth of car ownership, the traffic problems in central area of metropoles such as Seoul would become increasingly degraded. comparing with most western cities, the problems in Seoul are characterized by the improportionately high rates of intersection delay, station congestion, traffic accidents caused by weaving conflicts and pedestrian congestion. It is caused by the lack of flexibility I street network, which is prerequisite for upholding the efficacy of traffic management and control, resulted from the simplicity of network graph in terms of connectivity, street density and distribution by width. This pattern has been resulted from the prolonged policy pursuing the street-widening of the nagging bottleneck in such a short period since the 1950s, comparing that most western cities had undergone over several centuries an age of horse-and-vehicle transportation. In order to improve the expected traffic problems in central area over the coming periods of motorization, it is imperative to restructure the street network in Central Seoul so that the efficacy of traffic management and control may be operative. Based upon the long-range planning the street network should be restructured by stages so that cenral traffic may be controled by one-way operation and most through-traffic be detoured around fringe area.

• Smart Media Journal
• /
• v.4 no.2
• /
• pp.46-54
• /
• 2015

Communication between ECUs (Electronic Control Units) in agricultural machineries tends to use IS011783 widely, that is PGN (Parameter Group Number) based communication protocol lays on CAN protocol by altering its identifier part. Messages in line are transferred and received between ECUs according to ISO11783 standard. This paper discusses about design of wireless monitoring system. We used an ARM Cortex-M3 microcontroller embedded development board and marvel8686 wireless module. The wireless ISOBUS monitoring system, attached to communication line, reads messages, interpret them, and display them on the screen in easily comprehendible form. It can be used to generate messages and monitor the traffic on physical bus systems. The monitoring system connected to ECUs, monitor and simulate real traffic of communication and functionality of the ECUs. In order to support our work, we have implemented the monitoring tool. The development consists of two parts: GUI of the application and firmware level programming. Hence the monitoring system is attached to the communication line and equipped by Wi-Fi module; farmer/dispatcher in a farm monitors all messages in communication line on personal computer and smart device.

• 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.

• Journal of architectural history
• /
• v.16 no.2
• /
• pp.79-98
• /
• 2007

The building site was presumed as the Howonjeokwon or the Dasiwonji established at the traffic route among western inland areas in old Pyeonghaegun. The groundwork was composed inclination terrace of two steps. The upper step was the territory of the main house of ceremony symbolic+lodging function and the down step was divided in the territory of both Ikrang-chae of boarding and lodging management function and the territory of Haengrang-chae pavilion of rest reception management. The building composition by each territory formed space differentiation with the line of flow according to the thorough rule of court rank. The arrangement composition set the strong center axis in tandem, and it was the building arrangement interpreting the territory and the rule of court rank by function as the relationship of master and servant and was the building type emphasizing on the whole unity with the geometric symmetry structure. The Dasiwonji and the Hyeeumwonji had the common point which is the traffic architecture of semi governmental management reinforcing the boarding lodging function in the place which a visitor stayed. The Haeeumwonji and Dasiwonji had the difference in the size, but was the same in the composition system of construction. The external space and the system of the line of flow decided from the functional territory separation and the hierarchical rank as thorough as the geometric arrangement focusing on the whole unity. Namely, it was the strict and unusual system of the line of flow depended on the thorough rule of court rank than the efficient approach or arrangement of the line of flow. After being established to be the Howonjeokwon at the end of Koryeo, it disappeared at the time of the invasion of Japanese pirates when it was the time of the King Woo in Koryeo. It is presumed that it was continued until both wars, Imjin Byeongja, ago after changing its name to the Dasiwon, being restored to the small size at the end of Koryeo at the early of Choseon.