• Journal of Korean Institute of Industrial Engineers
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• v.39 no.4
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• pp.253-259
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• 2013

Investment scenarios in the transportation network design problem usually contain installation or expansion of multi-mode transportation links. When one applies the mode choice analysis and traffic assignment sequentially for each investment scenario, it is possible that the travel impedance used in the mode choice analysis is different from the user equilibrium cost of the traffic assignment step. Therefore, to estimate the travel impedance and mode choice accurately, one needs to develop a combined model for the mode choice and traffic assignment. In this paper, we derive the inverse demand and the excess demand functions for the multi-mode multinomial logit mode choice function and develop a combined model for the multi-mode variable demand traffic assignment problem. Using data from the regional O/D and network data provided by the KTDB, we compared the performance of the partial linearization algorithm with the Frank-Wolfe algorithm applied to the excess demand model and with the sequential heuristic procedures.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.6
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• pp.1-12
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• 2010

This study aims at analyzing the development status of surroundings of natural environment conservation areas and securing an adequate distance from development activities to conserve natural environment conservation areas efficiently or developing an improvement plan for setting conservation areas. Findings from the study shows that 1) rather than simply designating a legal natural environment conservation area, a conceptual scope approach of a "core area", "buffer area", and "transition area" such as in zoning of a "biosphere reserve" by UNESCO is recommended; 2) when setting an adequate range in a natural environment conservation area, it should be set by fully considering locational situation and the regional and environmental features of surroundings rather than setting a certain distance uniformly; 3) instead of designating wetlands only as a conservation area, entry and exit areas should be also included as buffer areas and in the case of wild animals, not only habitats but also feeding areas should be designated as conservation areas; and 4) an adequate horizontal separation space is important in the case of ground development, but for natural resources related to subterranean water and geological situation such as wetlands, an adequate vertical separation space should be fully considered.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.1
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• pp.89-96
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• 2020

Adverse impact of Particulate Matters(PM10, PM2.5; PMs) significantly affects daily lives. Major countermeasures for reducing concentration of PMs were focused on emission source without considering spatial difference of PMs concentration. Thus, this study analyzed spatial·temporal distribution of PMs with observation data as well as potential contributing factors on PMs concentration. The annual average concentration of PMs have been decreased while the particulate matter warnings and alerts were significantly increased in 2018. The average concentration of PMs in spring and winter was higher than the other seasons. Also, the spatial distribution of PMs were also showed seasonality while concentration of PMs were higher in Seoul-metropolitan areas in all seasons. Climate variables, emission source, spatial structure and potential PM sinks were selected major factors which could affects on ambient concentrations of PMs. This paper suggest that countermeasures for mitigating PM concentration should consider characteristics of area. Climatic variables(temperature, pressure, wind speed etc.) affects concentrations of PMs. The effects of spatial structure of cities(terrain, ventilation corridor) and biological sinks(green infrastructure, urban forests) on concentration of PMs should be analyzed in further studies. Also, seasonality of PMs concentration should be considered for establishing effective countermeasures to reduce ambient PMs concentration.

• Journal of Korean Society of Rural Planning
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• v.11 no.3 s.28
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• pp.43-52
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• 2005

Twelve selected rural villages were investigated to identify typical Korean rural landscapes. Among many photos taken in those villages, which are believed to represent rural amenities, one hundred photos were selected and again sixty of them were chosen through a questionnaire survey of landscape students. Two hundred domestic subjects and one hundred and one overseas visitors were surveyed to find their evaluations of 'rurality' of the Korean rural landscapes and their 'preferences' of those landscapes. Photo numbers 16, 40, 48, 37, 49, 11, 8, 56, 15 were evaluated most 'rural' and/or 'preferable' by domestic subjects. As the overseas visitors 'mrurality', they were asked to evaluate their 'preferences' only. Photo numbers 60, 7, 38, 28, 59, 15 were the most preferred Korean rural landscapes by them. In summary, Korean public generally preferred rural landscapes with natural beauty and, on the other hand, overseas visitors most preferred historic rural landscapes. Both group preferred least rural landscapes with man made structures.

• Journal of Korean Society of Rural Planning
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• v.26 no.3
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• pp.13-24
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• 2020

As the importance of rural landscapes has recently emerged due to an increase in number of urban to rural migrants into suburban area in Korea, this study empirically grasps the differences in subjective landscapes perceptions between native and non-native residents. and tried to explore new landscape management possibilities through the role of each residents group. To this end, based on the data collected through the 'photo-elicitation with walking', the residents' landscape perception objects, perception factors, and perceived feelings are derived, and then the differences and characteristics of landscapes perception between native and non-native residents group were analyzed. As a result, native residents perceived everyday landscapes relatively meaningfully and provided abundant information in all aspects, while non-native residents mainly recognized characteristic landscapes and responded more sensitively to visual and environmental perception factors than the natives. Non-native residents also showed strong willingness to improve the degraded landscapes. These results are expected to provide a basis for exploring the role of residents in rural landscape planning and management in the future.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.3
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• pp.274-290
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• 2019

This article links the change in regional manufacturing employment in Korea after the financial crisis to the geography of technological and trade shocks. We conceptualize the trade shock as the rapid growth in Korean imports from and exports to China and ASEAN countries. We then measure the exposure to technological shocks as the degree to which regions are specialized in routine tasks, which are susceptible to automation technologies. Results show that local labor markets specialized in routine tasks experience significant falls in manufacturing employment. Regions whose industrial structure exposes them to rising import competition experience sharp drop in manufacturing employment. We also found that export plays a major role in explaining the growth of regional manufacturing employment.

• Proceedings of the KOR-KST Conference
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• 2000.02a
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• pp.25-47
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• 2000

In route guidance systems fastest-path routing has typically been adopted because of its simplicity. However, empirical studies on route choice behavior have shown that drivers use numerous criteria in choosing a route. The objective of this study is to develop computationally efficient algorithms for identifying a manageable subset of the nondominated (i.e. Pareto optimal) paths for real-time vehicle routing which reflect the drivers' preferences and route choice behaviors. We propose two pruning algorithms that reduce the search area based on a context-dependent linear utility function and thus reduce the computation time. The basic notion of the proposed approach is that ⅰ) enumerating all nondominated paths is computationally too expensive, ⅱ) obtaining a stable mathematical representation of the drivers' utility function is theoretically difficult and impractical, and ⅲ) obtaining optimal path given a nonlinear utility function is a NP-hard problem. Consequently, a heuristic two-stage strategy which identifies multiple routes and then select the near-optimal path may be effective and practical. As the first stage, we utilize the relaxation based pruning technique based on an entropy model to recognize and discard most of the nondominated paths that do not reflect the drivers' preference and/or the context-dependency of the preference. In addition, to make sure that paths identified are dissimilar in terms of links used, the number of shared links between routes is limited. We test the proposed algorithms in a large real-life traffic network and show that the algorithms reduce CPU time significantly compared with conventional multi-criteria shortest path algorithms while the attributes of the routes identified reflect drivers' preferences and generic route choice behaviors well.

• Journal of Climate Change Research
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• v.8 no.1
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• pp.1-10
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• 2017

Over the past centuries, industrialization in developed and developing countries has had a negative impact on global warming, releasing $CO_2$ emissions into the Earth's atmosphere. In recent years, the transportation sector, which emits one-third of total $CO_2$ emissions in the United States, has adapted by implementing a climate change action plan to reduce $CO_2$ emissions. Having an environmental policy might be an essential factor in mitigating the man-made global warming threats to protect public health and the coexistent needs of current and future generations; however, to my best knowledge, no research has been conducted in such a context with appropriate statistical validation process to evaluate the effects of climate change policy on $CO_2$ emission reduction in recent years in the U.S. transportation. The empirical findings using an entity fixed-effects model with valid statistical tests show the positive effects of climate change policy on $CO_2$ emission reduction in a state. With all the 49 states joining the climate change action plans, the U.S. transportation sector is expected to reduce its $CO_2$ emissions by 20.2 MMT per year, and for the next 10 years, the cumulated $CO_2$ emission reduction is projected to reach 202.3 MMT, which is almost equivalent to the $CO_2$ emissions from the transportation sector produced in 2012 by California, the largest $CO_2$ emission state in the nation.

• Journal of Species Research
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• v.11 no.2
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• pp.117-127
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• 2022

This study is based on crane fly specimens collected during an 80-year period (1937-2017) in the Republic of Korea and Democratic People's Republic of Korea, and are in collections maintained at the United States National Museum, Smithsonian Institution, Washington DC, USA; the Snow Entomological Museum, University of Kansas, Lawrence, KS, USA; and the National Institute of Biological Resources, Incheon, South Korea. These crane flies are developing in wet places which usually prevail at lower altitudes, but such areas are often used for agriculture and human settlements, making natural habitats scarce and fragmented. Probably because of that, Limnophila crane flies are rare on the Korean Peninsula and were unnoticed by previous researchers. The genus Limnophila Macquart, 1834 with three species being new record for the Korean Peninsula: L. (Limnophila) japonica Alexander, 1913, L. (L.) pictipennis (Meigen, 1818) and L. (L.) politostriata Alexander, 1934a. General information are presented for each species, such as on genus and subgenus, redescriptions of species based on Korean specimens, illustrations of both sexes, elevation range, period of activity, habitat information, general distribution, and a distribution map for the Korean Peninsula.

• Journal of Agricultural Extension & Community Development
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• v.29 no.3
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• pp.173-189
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• 2022

This study aims to evaluate the location suitability of the Living SOC Project in rural areas. For the assessment of location suitability, we applied location efficiency and location equity, respectively. One hundred sixteen national sports centers in 57 rural areas are selected as the target of analysis. The location efficiency and location equity in each sports center revealed a large gap between facilities. The location suitability evaluation results examined in 57 rural areas were similar to those analyzed at individual facilities. The correlation between the location suitability results and rural characteristics was weak. Also, location efficiency and location equity have a fragile relationship. In the light of these results, the location of the sports center, whose supply has been confirmed in rural areas through the Living SOC project, does not consider regional characteristics actively. In addition, it is difficult to say that the location efficiency and location equity of sports centers have been proactively estimated. Therefore, breaking away from the performance-oriented policy and switching to a lifestyle SOC supply policy based on the pre- and ex-post location evaluation system is necessary.