• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.80-89
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• 2016

The median exclusive bus lanes with the purpose of improving public transport as part of a public transport promoting policy propel to improves the speed of the bus and guarantee punctuality security of public transportation for citizen satisfaction. In Median Exclusive bus lanes, Intersection operational methods are classified as turn prohibition, left turn, left turn U-Turn after turn prohibition. However, there are not clear criteria for applying for turn left U-Turn and related researches. The purpose of this study is to search a method for more safely operation when we operate turn left U-Turn in median exclusive bus lanes intersection. As a result, Bus stop in median exclusive bus lane should set back 12m for left turn, 17m for left turn U-turn during 60km/h and set back 13m for left turn, 17m for left turn U-turn during 50km/h.

• Journal of Korean Society of Transportation
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• v.21 no.6
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• pp.89-99
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• 2003

Considering a path represented by a sequence of link numbers in a network, the vine is differentiated from the loop in a sense that any link number can be appeared in the path only once, while more than once in the loop. The vine provides a proper idea how to account for complicated travel patterns such as U-turn and P-turn witnessed nearby intersections in urban roads. This paper proposes a new algorithm in which the vine travel pattern can be considered for finding K number of sequential paths. The main idea of this paper is achieved by replacing the node label of the existing Yen's algorithm by the link label technique. The case studies show that the algorithm properly represent the vine travel patterns in searching K number of paths. A noticeable result is that the algorithm may be a promising alternative for ITS deployment by enabling to provide reasonable route information including perceived traveler costs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.4
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• pp.60-67
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• 2010

Delay reduction of vehicles at the intersection is highly dependent on the signal operation method. Most previous traffic operations have focused on minimizing delay by adjust traffic offset. However, these methods have limitation in solving traffic problem if the volume reaches or exceeds the capacity. In this paper, it was analyzed that the effectiveness of various signal operation methods such as left-turn prohibition, and using protected mixed with permitted left turn using the traffic data from Daejeon city. In case of the left-turn prohibition of a intersection, the control delay reduced from 54.2 seconds to 22.7 seconds and especially, the delay of the southbound was drastically reduced. In addition, the delay was highly reduced from 27.0 seconds to 12.1 seconds when the operation system was changed to use protected mixed with permitted left turn.

• Journal of Korean Society of Transportation
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• v.17 no.3
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• pp.73-85
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• 1999

In metropolitan area, intersections having turn Prohibitions are often found and it is important to consider them in path planning. This Paper presents a new path planning method road networks having turn prohibitions. A new road network model is proposed in which an alter-native route for each turn-Prohibition is constructed in off-line using U-turn or P-turn and then Put into road network database. The proposed network model is efficient since it requires no virtual nodes that are usually used in the conventional road networks to represent turns at intersections. In order to find a shortest path with the proposed network, a new shortest path algorithm is proposed. A knot for the turn-Prohibited node is newly defined and is used in comparing the cost of the alternative route with that of the other path.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.696-706
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• 2007

Multiprocessor system on chip (MPSoC) platform has set a new innovative trend for the System on Chip (SoC) design. With the rapidly approaching billion transistors era, some of the main problem in deep sub-micron technologies characterized by gate lengths in the range of 60-90 nm will arise from non scalable wire delays, errors in signal integrity and un-synchronized communication. These problems may be addressed by the use of Network on Chip (NOC) architecture for future SoC. Most future SoCs will use network architecture and a packet based communication protocol for on chip communication. This paper presents an adaptive wormhole routing with proactive turn prohibition to guarantee deadlock free on chip communication for NOC architecture. It shows a simple muting architecture with five full-duplex, flit-wide communication channels. We provide simulation results for message latency and compare results with those of dimension ordered techniques operating at the same link rates.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.85-96
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• 2001

This paper discusses the problem of finding the Origin-Destination(O-D) shortest path in urban road networks that have variable special qualifies such as time windows for passing as well as geometrical special qualities such as U-turn and left-turn prohibition. The focus of this paper is motivated by the problem of finding minimum travel time paths for an advanced traveler information system (ATIS) in the context of intelligent transportation system(ITS) application. The transportation network with variable and geometrical special qualities is a more realistic representation of the urban road network in the real word. But, the traditional and existing shortest path algorithms can not search practical shortest path that variable special quality is reflected. This paper presents a shortest path algorithm which can search reasonable shortest path information for the urban ATIS application within a real time. The algorithm is based on genetic algorithm(GA). The high performance of the proposed algorithm is demonstrated by computer simulations.

• Journal of Korean Society of Transportation
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• v.33 no.5
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• pp.441-448
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• 2015

This study aims to suggest a reasonable signal operation method for right-turn traffic management. It was found that the right-turn vehicle supplementary signal is currently operated without clear regulations or criteria. It was also analyzed that right-turn supplementary signals are used without consistency, there is a risk of traffic accidents due to the discordance between supplementary signals and traffic signals of forward vehicles, there is a lack of basis for prohibition of a right turn when right-turn vehicle's supplementary signal is red and the flashing red signal is used in a different sense from the law. In order to see the effect of the installed right-turn vehicle supplementary signals on traffic signal violation, a field investigation was conducted. As the result, there was a high proportion of signal violation on the approach lane with right-turn supplementary signals and this means that right-turn supplementary signals hardly influenced the reduction in proportion of signal violation during a right turn. Additionally, a survey was carried out to see if there were differences in driver's interpretation of traffic signals depending on the installation of right-turn supplementary signals. As the result of the survey, there were no differences in interpretation of traffic signals depending on the installation of right-turn supplementary signals or the types of right-turn supplementary signals. A right turn when the signal was red did not lead to serious traffic accidents, so it is thought that there should be a careful consideration of a total ban on a right turn when the signal is red, in order to prevent driver's confusion due to the change of the signal system. Unless there is a disturbance to cars and pedestrians after a temporary stop when the signal is red, there is a need to specify that vehicles must stop temporarily in the Road Traffic Act to facilitate a right turn. What this study finally suggested is to use tri-colored arrow signals for right-turn car supplementary signals to convey a signal to a driver clearly.

• Journal of Korean Society of Transportation
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• v.11 no.1
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• pp.67-86
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• 1993

A formulation of dynamic traffic assignment between multiple origins and single destination was first introduced in 1987 by Merchant and Nemhauser, and then expanded for multiple destination in the late 1980's (Carey, 1987). Based on behavioral choice theory which provides proper demand elasticities with respect to changes in policy variables, traffic phenomena can be analysed more realistically, especially in peak periods. However, algorithms for these models are not well developed so far(working with only small toy network) and solutions of these models are not unique. In this paper, a new model is developed which keeps the simplicity of static models, but provides the sensitivity of dynamic models with changes of O-D flows over time. It can be viewed as a joint departure time and route choice model, in the given time periods(6-7, 7-8, 8-9 and 9-10 am). Standard multinomial logit model has been used for simulating the choice behavior of destination, mode, route and departure time within a framework of the incremental network assignment model. The model developed is workable in a PC 386 with 175 traffic zones and 3581 links of Seoul and tested for evaluating the exclusive use of Namsan tunnel for HOV and the left-turn prohibition. Model's performance results and their statistical significance are also presented.

• Journal of Korean Society of Transportation
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• v.22 no.1 s.72
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• pp.7-18
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• 2004

To solve the urban traffic congestion problem, Seoul and other major cities have operated the reversible lanes as Transportation Systems Manage-ment(TSM) method since 1981. However, few studies have been conducted to measure the effectiveness of reversible lane implementation and operation, and the reversible lanes have been implemented based on the experiential warrants rather than the study-based warrants. In this Paper the effect of reversible lanes operation has been analyzed by using the average delay and the fuel consumption. Four factors such as in and out flow of directional v/c, the ratio of directional volume, the number of reversible lanes and left-turn treatment(prohibition of LTs or protected LTs) were used to estimate the implementation effect of reversible lane operation by using TRANSYT-7F simulation package. In the case of six-lane urban arterial, the lower ratio of directional volume was found to warrant the reversible lanes when the simulation-based method was applied compared with the current experiential warrants.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.37-61
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• 2013

In modern international law, the absence of legal definition regarding drone(Unmanned Aerial Vehicle) has made legal scholars work on an typical analogy between aircraft codified in the international document and drone. The wording of the Convention on International Civil Aviation is limited to two categories of aircraft, such as civil aircraft and state aircraft, whereas military aircraft is not legally defined. As such it is, the current practices of the State regarding the drone flight over foreign territory have proven a hypothese that drone is being deemed as military aircraft. Principal usage of drone lies in reconnaissance and surveillance mission as well as so-called targeted killing, which is prohibited if the killing is treacherous. Claimed war against terrorism, however, is providing a legal rationale that targeted killing is not treacherous, and that the targeted person is not civilian but combatant. In such context, armed attack of drone is deemed legal and justified. Consequently, such attack is legal in the general context of the war. The rules that govern targeting do not turn on the type of weapon system used, and there is no prohibition under the laws of war on the use of technologically advanced weapons systems in armed conflict so long as they are employed in conformity with applicable laws of war. Drones may present interesting new challenges because of their sophistication and the technological advantage they convey to their operators.