• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.160-173
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• 2013

In this paper, we propose a new visual odometry technique by combining a forward-looking stereo camera and a backward-looking monocular camera. The main goal of the proposed technique is to identify the location of a moving vehicle which travels long distance and comes back to the initial position in urban road environments. While the vehicle is moving to the destination, a global 3D map is updated continuously by a stereo visual odometry technique using a graph theorem. Once the vehicle reaches the destination and begins to come back to the initial position, a map-based monocular visual odometry technqieu is used. To estimate the position of the returning vehicle accurately, 2D features in the backward-looking camera image and the global map are matched. In addition, we utilize the previous matching nodes to limit the search ranges of the next vehicle position in the global map. Through two navigation paths, we analyze the accuracy of the proposed method.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.952-959
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• 2012

This study examined habitat fragmentation that has occurred in Paju and Yeoncheon, the two border municipalities between North and South Korea in Gyeonggi-do (province) during the last 17 years using various landscape metrics. We 1) classified grass and agricultural habitats and forest habitats from two Landsat TM images collected in 1990 and 2007, and 2) compared the percentage of class area, patch density, mean patch area, and mean perimeter area ratio for the two habitat types between the two time points. Both types of habitats has been severely fragmented due to urban development in the last 17 years. The increased patch density and decreased mean habitat area are attributed to the construction of roads and railroads that separate a large habitat to many small pieces. The increased mean perimeter area ratio also indicates that the habitat fragmentation extended areas that are affected by the edge effect and so less suitable for interior species. A habitat conservation plan is urgently needed to minimize habitat fragmentation from developments that are expected to soon occur in the north and south Korean border.

• Journal of the Korean Geographical Society
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• v.49 no.6
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• pp.849-864
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• 2014

The objective of this paper is to investigate both the processes of regional policy and their determinants of the International Garden Exposition Suncheon Bay Korea 2013(IGEXPO 2013). IGEXPO 2013 was held in Suncheon from April to October 2013, and almost 440 million tourists visited to IGEXPO 2013. The processes of regional policy of the IGEXPO initiative were divided into four stages; the first stage from 1992 to 2002 was a beginning of conservation movement for Suncheon Bay; the second stage from 2003 to 2007 was a constructing of natural ecological park of Suncheon Bay; the third stage from 2008 to 2010 was a beginning of IGEXPO initiative and a confirming of the IGEXPO 2013; the four stage from 2011 to 2013 was a preparing and holding of IGEXPO 2013. The major determinants related to regional policy development process of IGEXPO initiative are the population n movement for Suncheon Bay, the rergional development strategy for central city in Gwangyang Bay area, the leadership for continuity of regional policy oriented to environmental and ecological city, and the cooperation and competition relationalship with neighboring city, in particular Yeosu city and 2012Yeosu EXPO planning. IGEXPO 2013 has been evaluated as having some performances such as the enhancement of city image, establishment of city park as a public goods, and formation of community leadership promoting continuous urban policy for environmental & ecological city.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.86-97
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• 2018

City tour service has a function not only informs tourists of historical and cultural resources in the city but also contributes to improving city image making. In this study, a questionnaire was surveyed to tourists who used Suwon city tour to find out which factors make affect their intention to re-visit or recommendation to others. Structural equation model was constructed and set a hypothesis that overall city tour satisfaction would have a positive effect. The fitness of the final model was found out to be meet the statistical criteria. As a result of the final model, both satisfaction of guide and satisfaction of city tour operation were significant at 5% significance level (P<0.01). On the other hand, both satisfaction of bus facility and of promotion, customer service were statistically insignificant. Consequently, City tour service satisfaction was found to effect to the intention of re-visit and recommendation. Especially, The higher the satisfaction of guide and city tour operation, the more tendency to recommend. It is expected that local government which operates city tour bus could take advantage of this result in the future.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.165-172
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• 2017

High frequency squeal noise can be generated when a railroad vehicle runs a sharp curved section; this noise causes environmental complaints and excessive wear on the wheel and the railroad track. In this paper, curved squeal noise experiments on a commercial railway were carried out to investigate this phenomenon. The relationship of the squeal noise pressure level, the frequency characteristics, the railway running speed, and the modal behavior of the wheel were investigated. At the same time, the lateral motion of the wheel relative to the rail was captured using a video camera; wheel movement was calculated when the noise was generated. queal noise occurred at the highest level at the inner front wheel; this phenomena is considered to be related to the lateral vibration response characteristics of the wheel. It can be seen that the magnitude of this squeal noise is not directly related to the increase in vehicle speed.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.570-580
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• 2015

In the study, planning indicator that should be considered in applying traffic calming technique was derived, and it was intended to analyze the importance of indicator that should most considered in planning traffic calming technique through AHP analysis on the basis of it. The result of planning indicator may be summarized by dividing into road section and crossing section. In road section, hump (0.35) for equipment stimulating reduction of speed, hump image/fort (0.31) for visual control equipment, and slalom type road (0.52) for chicane, and bollard (0.47) for blocking passing route are shown to be the most important and come before anything. In crossing section, signal indicator (0.33) for visual control equipment, rumble strip (0.44) for equipment stimulating reduction of speed, zigzag type road (0.65) for chicane, and blocking going straight at crossing (0.45) for blocking passing route are shown to be the most important and come before anything. The result of the study is judged to be used for basic material in applying traffic calming technique and establishing policy hereafter.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.113-124
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• 2012

The purpose of this study is to analyze community members' perception due to impacts on use and development of Dulegil in Bukhansan National Park. The study was conducted by questionnaire survey sent to community members of the vicinity of Dulegil. Average score of positive impact on the local community was 3.2. Positive impacts mentioned by community members were 'heightened pride in their community with increased community image' and 'improvement of landscape and natural environment.' Improved residents' awareness of landscape and natural environment indicated that Dulegil almost accomplished intended goal of preservation of ecosystem. However, actual effects on ecosystem preservation and local economy were not perceptible yet. Score of negative impact was 2.8 on average. 'Traffic congestion' and 'increase in noise level' were considered the most serious among the negative impacts. Environmental pollution and destruction of vegetation in the lowland were deemed relatively bad. Regarding resident awareness of community, those in their 50s and older were quite satisfied with the community. However, young people showed lower level of satisfaction. In order to satisfy all ages, infrastructure and programs for the youth should be in place. To minimize negative awareness of impacts of Dulegil, visitor's attitude should be changed, and education and training on the value and mind set of horizontal hiking are required.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.182-194
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• 2017

Most of the drone (Unmanned Aerial Vehicle) research in terms of traffic management involves detecting and tracking roads or vehicles. The purpose of analyzing image footage in the transportation sector is to overcome the limitations of the existing traffic data collection system (vehicle detectors, DSRC, etc.). With regards to this, drones are the good alternatives. However, due to limitation in their maximum flight time, they are appropriate to use as a complementary rather than replacing the existing collection system. Therefore, further research is needed for utilizing drones for transportation analysis purpose. Traffic problems often arise from one particular section or a point that expands to the whole road network and drones can be fully utilized to analyze these particular sections. Based on the study on the uses of traffic survey analysis, this study is conducted by extracting traffic flow parameters from video images(range 800~1000m) of highway unit segments that were taken by drones. In addition, video images were taken at a high altitude with the development of imaging technologies.

• Geophysics and Geophysical Exploration
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• v.5 no.4
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• pp.236-249
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• 2002

We have extended the three-dimensional (3-D) resistivity imaging algorithm to cover the 3-D resistivity tomography problem, where resistivity data are acquired using electrodes installed in several boreholes as well as at the earth surface. The imaging algorithm consists of the 3-D finite element forward modeling and least-squares inversion scheme, where the ACB (Active Constraint Balancing) is adopted to enhance the resolving power of the inversion. Sensitivity analysis with numerical verifications shows that 3-D resistivity tomography is a very appealing method and can be used to get 3-D attitude of subsurface structures with very high-resolution. Moreover, we could accurately handle the topography effect, which could cause artifacts in the resistivity tomography. In the application of 3-D resistivity tomography to the real field data set acquired at the quarry mine, we could derive a very reasonable and accurate image of the subsurface.

• Journal of Cadastre & Land InformatiX
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• v.50 no.1
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• pp.215-229
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• 2020

In response to the recent 4th industrial revolution, the demand for 3D object models in the latest fields of digital twin, autonomous driving, and VR/AR, as well as the existing fields such as city, construction, transportation, and energy has increased significantly. It is expected that the demand for 3D object models with various precision from LOD1 to LOD4 will increase more and more in various industry fields. However, the Ministry of Land, Infrastructure and Transport, and the local government and the private sector have partially built 3D object models of different precisions for some specific regions because of the huge cost. Therefore, this study proposes a feasible plan that can solve the cost problem in generating 3D object models for the whole territory. For our purpose, we first analyzed usage, demand, generation technology and generation cost for 3D object models. Afterwards, we proposed LOD3 model generation plan for all territory using automatic 3D object model generation technology based on image matching. Additionally, we supplemented the proposed plan by using LOD4 generation plan for landmarks and LOD2 generation plan non-urban area. In the near future, we expect this would be a great help in establishing a feasible and effective 3D object model generation plan for the whole country.