• Journal of KSNVE
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• v.9 no.1
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• pp.25-32
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• 1999

Ground vibrations induced from road were investigated to get the basic data that can be used to prepare countermeasures for environmental vibration problems. Vibration levels were measured simultaneously at three points in double distances from road. These data were analyzed with the type of vehicles. roads, media to understand the magnitudes and characteristics of distance attenuation of road vibrations. Vibration levels recorded on tapes were analyzed to understand the characteristics of frequency of road vibration. The range which could be influenced by the road vibration was estimated to take into account the mean of$L_{max}$ and distance attenuation of vibration level 5 m from roadside.

• Journal of the Society of Disaster Information
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• v.5 no.1
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• pp.30-44
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• 2009

Asphalt concrete pavements are often destroyed within the intended design life due to the increasement in traffic volume. The most common types of asphalt concrete pavement damages are permanent deformation and fatigue cracking, and so on. In this research, characteristics of traffic loadings and lateral wheel path distributions are analyzed using the field survey on traffic flow. The obtained traffic characteristics can be used to the decision making for the maintenance policy of roads. According to the traffic lane analysis for the 2nd and 3rd lanes, inner lane vehicles tended to pass to the right side to avoid the opposite side vehicles. In addition, the outside lane vehicles were deviated to the left side to avoid passengers. It is also noted that the lateral wheel path distributions was close to the normal distribution.

• Journal of Korean Society of Transportation
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• v.33 no.3
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• pp.304-314
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• 2015

Detour of metro (subway) in metropolitan area has been regarded as one of inherent elements that make entire metro system less competitive than passenger cars. However, factors affecting detour of metro line is not specified clearly when a new subway system is planned or an existing system is improved. Previous detour-related studies was reviewed for developing 'distance efficeincy evaluation model' for metro as well as its counterpart (i.e. road). Metro line 3 (orange line) of Seoul metropolitan area was applied as a case study. As a results, the most detoured OD segment is Daechi - Apgujeong and its detour factor is 1.93 which means that the distance of the metro is 1.93 times longer distance compared to the distance of the road. The metro line 3 has averagely 20% longer distance compared to road for the identical O/D pairs.

• Journal of Korean Society of Forest Science
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• v.90 no.5
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• pp.643-649
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• 2001

The case study of the Cooperatives' members and Sincere Forest Managers/Forest Successors was carried out to find the determinants affecting the forest investment of private forest owners and analyze their effects on it. For this the landowners' forest investment probability function was estimated using the logistical regression model. The results showed that the forest investment of the Cooperatives' members was the function of forest area, stand age, forest income, and technical assistance. Three of the variables (forest income, forest area, and technical assistance) exhibited a positive effect on the forest investment as expected, while stand age showed a negative effect unlike the expectation of the study. In case of Sincere Forest Managers and Forest Successors forest area, distance(1)(distance from forest to road accessible by vehicle), knowledge of financing program, and forest income were significant indicators for the forest investment. All these variables showed the expected signs; forest area, knowledge of financing, and forest income had a positive effect on the forest investment, and distance(1) showed a negative effect.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.111-122
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• 2012

There has been a strong demand for providing diverse services to drivers utilizing existing ITS infrastructure. To this end, this study is aiming at improving the accuracy of a variable speed limit system by determining recommended speeds for the system utilizing the information from Urban Traffic Information System(UTIS) and Weather Information System(WIS). In order to determine appropriate speed limits under inclement weather conditions for the variable speed limit system, this study examined three methods: i) the method utilizing the information from WIS, ii) the method utilizing the information from UTIS, and iii) the method which combines the information from WIS and UTIS using different weights for diverse weather conditions. Finally, this study selected the third method which determines an appropriate speed limit using the relationship between the vehicle operating speed and the minimum stopping distance which is estimated using the existing speed limit, surface coefficient of friction and superelevation.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1811-1825
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• 2011

This study analyzed the transit services with respect to transit service measures such as the load factor representing number of passengers between stops, dwelling time, and operational speed based on transit smart card data recorded in 2009. A case study on the local bus line 7024 connecting Seoul railway station to evaluate bus services at passenger perspectives was accomplished. From the results, we found that the dwelling time was not affected by the number of passengers which is because the tagging patterns are different among passengers. The operational speed was analyzed by calculating the average speed of the bus route and the speed of each bus stops based on dwelling time. Interestingly, calculating operation speed based on the transit smart card data is the first time effort ever made and this means that it is not necessary to observe travel speed of bus and railway at a field level any more. we hope that this study will be a basis of evaluation of transit services purely based on the transit smart card data and help to make better transit services for passengers and operators as well.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.63-74
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• 2005

When we introduce the BRT systems, it is very important to decide the operating factors, such as bus-stop locations or headway. If the factors are inappropriate, unessential expenses for the operator and users of the bus line may be caused, and it leads increase of social total cost. So, it is necessary that we consider users' origin and destination of each bus line when we set location of bus-stops and the optimal headway. Meanwhile, Smart Card System was introduced of fare collection for the Public Transportation Reform in Seoul last year. This new card system makes it possible to store up the information about bus operating and passenger's trip link. With these substantial information. we can estimate bus-stop-based O-D table. So, in this thesis, it was studied a systematic methodology to find the optimal location and headway for skip-stop bus system (as a type of first step for BRT). The proposed methodology in this thesis is expected to be useful to effect analysis or setting operating factors for skip-stop bus system in each bus line.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.129-139
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• 2010

This study proposes a model for measuring the connectivity of nodes in road networks. The connectivity index between two nodes is characterized by the number of routes, degree of circuitousness, design speed, and route capacity between the nodes. The connectivity index of a node is then defined as the weighted average of the connectivity indexes between the node and other nodes under consideration. The weighting factor between two nodes is determined by the travel demand and distance between them. The application of the model to a toy network shows that it reasonably well quantifies the level of connectivity of nodes in the network. If flow of rail networks can be measured in the same scale as that of road networks and the capacity of rail links can be estimated, the model proposed in this paper could be applied to intermodal transportation networks as well.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.243-250
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• 2016

As sustainable growth has been emphasized in the field of transportation, the railway system has been promoted as an environmentally-friendly transport mode. However, mode shifts from other transport modes to railway have been sluggish. In this context, to enhance the understanding of railway's competitive advantages and disadvantages, this research evaluates travelers'preferences for public transport modes for inter-regional trips: such understanding should make it possible to formulate effective policy for promoting railways. To this end, passenger recognition of competitive transport modes has been measured by applying multidimensional scaling analysis for six major inter-regional public transport services - KTX, ITX-Samaeul, Mugunghwa-ho, premium express bus, general express bus, and airline. As a result, we can conceptualize the recognition similarity in two-dimensional space, and understand how travelers perceive the six major transport modes.

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.161-169
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• 2010

The amount of energy consumed by a transportation system in a city is influenced not just by a transportation system itself but also by city's spatial character. Yet there have been very limited studies on this subject. This study investigates the factors that influence the energy consumption by a transportation system and city's spatial character. The model of an urban area confined within a definite boundary is assumed in order to develop the relationships between the energy consumption and the transportation system. Various assumptions on the character of a city and activities are made. An equation for computation of the energy consumption is derived with such factors as modal split, densities of residents and workers, as well as technological development. Using the equation, sensitivity analyses are performed in order to identify the relationships between energy consumption and influencing factors. It is found that the modal split is the most powerful factor that determines the energy consumption by the transportation system. Yet it is also found that the densities of residents and workers and the technological factors are very important in determining the amount of energy consumption as well.