• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6B
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• pp.551-560
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• 2009

This paper describes a newly developed pollutant transport model named ARPTM which was designed to simulate the transport and characteristics of pollutant materials after an accidental spill in upstream of river system up to a given position in the downstream. In particular, the ARPTM incorporated ADCP data to compute longitudinal dispersion coefficient and advection velocity which are necessary to apply one-dimensional advection-dispersion equation. ARPTM was built on top of the geographic information system platforms to take advantage of the technology's capabilities to track geo-referenced processes and visualize the simulated results in conjunction with associated geographic layers such as digital maps. The ARPTM computes travel distance, time, and concentration of the pollutant cloud in the given flow path from the river network, after quickly finding path between the spill of the pollutant material and any concerned points in the downstream. ARPTM is closely connected with a recently developed GIS-based Arc River database that stores inputs and outputs of ARPTM. ARPTM thereby assembles measurements, modeling, and cyberinfrastructure components to create a useful cyber-tool for determining and visualizing the dynamics of the clouds of pollutants while dispersing in space and time. ARPTM is expected to be potentially used for building warning system for the transport of pollutant materials in a large basin.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.91-98
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• 2004

This study focuses on the development of dynamic assignment for evaluation and application for dynamic route guidance strategy. Travelers are classified according to information contents which they received pre/on trip. The first group have no traffic information, so they travel with fixed route. The second group have real-time shortest path and travel according to it. The last group have car navigation system or individual method(cellular phone, PDA-two way communication available) for traffic information on trip. And then they are assigned in accordance with the proposed multiclass dynamic assignment model. At this time the last group is gotten under control with DFS(decentralized feedback strategy). In use of this Process we expect that various traffic information strategy can be tested and also be the key factor for success of ITS, location of VMS(variable message sign), cycle of information, area of traffic information, etc).

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.31-40
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• 2009

Some road charges toll to finance the cost or to manage traffic congestion. With a growth of PPI projects, toll roads would be increase continuously. Tolls have a considerable influence on user's route choice, and sometimes can affect to the departure time and even to mode choice. For modelling toll roads, user's WTP or VOT has an important role and it is general that VOT is equivalent to the wages of workers. The current way of modelling technique yields various toll price elasticity from low to high. When there exist few alternative routes, unrealistic result that all traffic assigned to some shortest path may occur. The toll price elasticity can be influenced by alternative route and congestion level, but some result shows nearly unrealistic patterns. The model to forecast more realistic toll road demand is very essential for estimating toll revenue, choice of optimal toll level & collecting location and establishing toll charge strategy. This paper reviewed some literatures about toll road modelling and tested case study about the assignment technique with different VOT. The case study shows that using different VOT yields more realistic result than the use of single VOT.

• Journal of the Korean Geotechnical Society
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• v.21 no.2
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• pp.37-46
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• 2005

In the field of earthquake engineering, recent improvements in many areas, such as seismological source modeling, analysis of travel path effects, and characterization of local site effects on strong shaking, have led to significant advances in both code-based and more advanced procedures for evaluating earthquake ground motions. A missing link, however, is empirically verified design procedures fur assessing the effects of soil-structure interaction (SSI). Available Soil-Structure Interaction (SSI) analysis techniques range from simple substructure-type procedures to relatively sophisticated finite element procedures. The most common substructure approach for foundation-soil interaction is to use a frequency-dependent and complex-valued impedance function. This study uniquely evaluates impedance functions for two well-instrumented sites w significant inertial SSI effects using a system Identification technique. The system identification analysis results are then compared to predictions from a simple theoretical model to gain insight into the inertial interaction effect in the subject sites.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.1
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• pp.13-20
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• 2012

In this study, the change pattern of hydrological response function as development has been observed. The target watershed was selected Tanbu sub-Basin in the Bocheong Basin. The applied channel networks are composed of 10 cases that are channel networks by strahler's ordering scheme and cases of all grids channel or the hillslope in basin. To each case of grid in basin, channel and hillslope drainage path lengths to outlet of basin are calculated, and hydrological response function was calculated by Nash Model. As results of this analysis, the peak discharge of hydrological response function is increased and peak time is shortened as development of channel networks. And based on statistical characteristics of hydrological response function, mean (lag time) and variance of travel time are reduced exponentially.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.161-172
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• 2005

This study is to develop Bus Transit Route Analysis and Evaluation Model that can product the quantitative performance measures for Bus Transit Route Network Design. So far, in Korea, there are no so many models that evaluate a variety of other performance measures or service quality that are of concern to both the transit users and operator because of lower-level bus database system and transit route network analysis algorithm's limit. The BTRAEM in this research differ from the previous approach in that the BTRAEM employs a multiple path transit trip assignment model that explicitly considers the transfer and different travel time after boarding. And we develop input-output data structure and quantitative performance measure for the BTRAEM. In the numerical experimental applying BTRAEM to Mandl transit network, We got the meaningful results on performance measure of bus transit route network. In the future, we expect BTRAEM to give a good solution in real transit network.

• Spatial Information Research
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• v.20 no.6
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• pp.33-43
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• 2012

As part of recent sustainable transport, bike has come into the spotlight as a green transport at close range to link between walking and public transit and also alterative to solve problems of existing vehicle travel. Some arguments on promotion of using bicycles have already been made in Europe, the U.S and other developed countries. To be sure, much has been written extensively in description of utilization of bike oriented by supplier, for examples, Level of Service with bike path, infrastructure such as bicycle racks and lounge etc. Therefore, our study has been differentiated in development of new evaluation model focused on level of bike user's satisfaction, comprehensively considering suitability for bikeway installation, connectivity of the public transportation system and stability in Incheon City. ANP(Analytic Network Process) analysis which is able to allow consideration of the interdependence of criteria has been hired due to multi-collinearity instead of AHP used in multi-criteria decision analysis. Last but not least, we drew bike route on a case-by-case for maintenance and improvement of its facility in Namdong-gu and Bupyeong-gu. To conclude, suggested finding has dem onstrated the validity of evaluation scheme for bikeways which is appropriate for type and purpose and ultimately this can be used to establish policy decision making for improvement of bikeway.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.4 s.316
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• pp.28-35
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• 2007

Airbone laser altimeters have been utilized for 3D topographic mapping of the earth, moon, and planets with high resolution and accuracy, which is a rapidly growing remote sensing technique that measures the round-trip time emitted laser pulse to determine the topography. The traveling time from the laser scanner to the Earth's surface and back is directly related to the distance of the sensor to the ground. When there are several objects within the travel path of the laser pulse, the reflected laser pluses are distorted by surface variation within the footprint, generating multiple echoes because each target transforms the emitted pulse. The shapes of the received waveforms also contain important information about surface roughness, slope and reflectivity. Waveform processing algorithms parameterize and model the return signal resulting from the interaction of the transmitted laser pulse with the surface. Each of the multiple targets within the footprint can be identified. Assuming each response is gaussian, returns are modeled as a mixture gaussian distribution. Then, the parameters of the model are estimated by LMS Method or EM algorithm However, each response actually shows the skewness in the right side with the slowly decaying tail. For the application to require more accurate analysis, the tail information is to be quantified by an approach to decompose the tail. One method to handle with this problem is proposed in this study.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.259-266
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• 2005

Recently data centric routing or application dependent routing protocols are emerged in mobile ad hoc networks. In this paper, we propose a routing method for query processing in MANET(Mobile Ad hoc NETwork) environment, called road-based query routing, with consideration on real time traffic information of large number of vehicles. In particular, we focus on the method that process arrival time dependent shortest path query in MANET without a central server on the road networks. The main idea of our approach lies in a routing message that includes query predicates based on the road connectivity and on data gathering method in real time from vehicles on the road by ad-hoc network. We unify route discovery phase and data delivery(query processing) phase in our mechanism and reduce unnecessary flooding messages by pruning mobile nodes which are not on the same or neighboring road segments. In order to evaluate the performances of the proposed method, we established a model of road networks and mobile nodes which travel along the roads. The measurement factor is the number of nodes to whom route request is propagated according to each pruning strategy. Simulation result shows that road information is a dominant factor to reduce the number of messages.

• Journal of Distribution Science
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• v.10 no.1
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• pp.43-52
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• 2012

With the slowdown in environmental issues and the change of environmental consciousness, ecotourism is being discussed in various social fields. Ecotourism is being popularized for environmental protection, and now it is becoming a mainstream product from one of mass tourism. Ecotourism's emphasis on sustainable development in the tourism destination's society, economy, and environment, through ecotourism study and education, enable people to understand the core value of the ecological environment. 2011 was nominated as "the Year of World Forest" by the UN. In the recent years, forests are becoming increasingly important with their own values and functions in environment, economy, society, and culture. In particular, the global environmental issues caused by climate change are becoming an international agenda. Forests are the only effective solution for the carbon dioxide that causes global warming. Moreover, forests constitute a major part of ecotourism, and are now most used by ecotourists. For example, Korea, wherein 60% of the land is forest, attracts ecotourists. With the increasing interests in environment, the number of tourists visiting the ecosystem forest, which is highly valued for its conservation, is increasing significantly every year and is receiving considerable attention from the government. However, poor facilities in the forest ecotourism sites and improper market strategies are the reasons for the poor running of these sites. Furthermore, tourists' environmental awareness affects ecology environmental pollution or the optimization of forest ecotourism. In order to verify the relationships among tourist attractiveness, environmental consciousness, charm degrees of the attractions, and attitudes after tours, we established some scales based on existing research achievement. Then, using these scales, the researcher completed the questionnaire survey. From December 20, 2010 to February 20, 2011, after conducting surveys for 12 weeks, we finally obtained 582 valid questionnaires, from a total of 700 questionnaires, that could be used in statistical analysis. First, for the method of research and analysis, the researcher initially applied the Cronbach's (Alpha) for verifying the reliability, and subsequently applied the Exploratory factor analysis for verifying the validity. Second, in order to analyze the demographics, the researcher makes use of the Frequency analysis for the AMOS, measurement model, structural equation model computing, and also utilizes construct validity, convergent validity, discriminant validity, and nomological validity. Third, for the analysis of the ecotourists' environmental consciousness, impacts on tourist attractiveness, charm degrees of the attractions, and attitudes after the tour, the researcher uses AMOS 19, with the path analysis and equation of structure. After the research, researchers found that high awareness of natural protection lead to high tourist motivation and satisfaction and more positive attitude after the tour. Moreover, this research shows the psychological and behavioral reactions of the ecotourists to the ecotourist development. Accordingly, environmental consciousness does not affect the tourist attractiveness that has been interpreted as significant. Furthermore, people should focus on the change of natural protection consciousness and psychological reaction of ecotourists while ensuring the sustainable development of ecotourists and developing some ecotourist programs.