• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.5
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• pp.64-78
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• 2019

This paper explores key factors affecting taxi travel using global positioning system(GPS) data in Seoul, Korea, considering spatial dependence. We first analyzed the travel characteristics of taxis such as average travel time, average travel distance, and spatial distribution of taxi trips according to the time of the day and the day of the week. As a result, it is found that the most taxi trips were generated during the morning peak time (8 a.m. to 9 a.m.) and after the midnight (until 1 a.m.) on weekdays. The average travel distance and travel time for taxi trips were 5.9 km and 13 minutes, respectively. This implies that taxis are mainly used for short-distance travel and as an alternative to public transit after midnight in a large city. In addition, we identified that taxi trips were spatially correlated at the traffic analysis zone(TAZ) level through the Moran's I test. Thus, spatial regression models (spatial-lagged and spatial-error models) for taxi trips were developed, accounting for socio-demographics (such as the number of households, the number of elderly people, female ratio to the total population, and the number of vehicles), transportation services (such as the number of subway stations and bus stops), and land-use characteristics (such as population density, employment density, and residential areas) as explanatory variables. The model results indicate that these variables are significantly associated with taxi trips.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.103-116
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• 2022

The South Korean Ministry of Land, Infrastructure, and Transport designated seven automated driving test beds required to evaluate vehicle performance every year for the expansion of mobility services based on automated driving. As a fundamental study, we suggested a necessary example of evaluating the performance with a satisfaction survey for the services before the evaluation. First, we surveyed the perception of automated driving services of users and the public in Sejong-si, South Korea. The survey showed that the users had a higher level of awareness of automated driving technology and intention to use it than the public. Second, the satisfaction survey was conducted on demand-responsive public transportation and automated driving service users. Notably, using the Wilcoxon Rank Sum Test, among the non-parametric statistical analysis methods, we found that safety-related factors affected the overall satisfaction of users of automated driving services. On the other hand, in the case of the demand-responsive public transportation service users, factors related to service convenience affected overall satisfaction. Hence, the results of these surveys are expected to be used as basic data and guidelines to improve the quality of automated driving services and policy establishment.

• Journal of the Korean Geographical Society
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• v.38 no.5
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• pp.701-724
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• 2003

Since the late 19th century, the location and characteristics of Lop-Nor lake have been a major theme of debates among the scholars(Prejevalsky, Richthofen, Kozlov, Hedin, Huntington, Stein, Chen etc.) who have been interested in Inner Asia. In the 1980s the problem to find the exact location and characteristics of Lop-Nor lake was finally solved by the investigation group of the Chinese Academy of Sciences. Ironically, it was possible to find the solution by drying up of the lake due to the change of land use and the expansion of irrigation system in Tarim basin. Specially the excessive development of this area for agricultural use by the Xinjiang Production-Construction Army Corps since 1949 must have influenced on drying up of Lop-Nor lake. Furthermore it can be observed to be the very similar situation to Lop-Nor lake in many areas of Chinese Inner Asia Frontier. According to this finding, it may be proposed that human factors played an important role in the changes of Lop-Nor lake over the previous years too. This study can give an insight on the ecological interpretation of Inner Asian history and the environmental interpretation of the rising nationalism in this area.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.7-7
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• 2017

Unfavorable weather and soil conditions reduce rice yield and land and water productivity, aggravating existing encounters of poverty and food insecurity. These conditions are foreseen to worsen with climate change and with the unceasing irrational human practices that progressively debilitate productivity despite global appeals for more food. Our understanding of plant responses to abiotic stresses is advancing and is complex, involving numerous critical processes - each controlled by several genetic factors. Knowledge of the physiological and molecular mechanisms involved in signaling, response and adaptation, and in some cases the genes involved, is advancing. Moreover, the genetic diversity being unveiled within cultivated rice and its wild relatives is providing ample resources for trait and gene discovery, and this is being scouted for rice improvement using modern genomics and molecular tools. Development of stress tolerant varieties is now being fast-tracked through the use of DNA markers and advanced breeding strategies. Large numbers of drought, submergence and salt tolerant varieties were commercialized over recent years in South and Southeast Asia and more recently in Africa. These varieties are making significant changes in less favorable areas, transforming lives of smallholder farmers - progress considered incredulous in the past. The stress tolerant varieties are providing assurance to farmers to invest in better management of their crops and the ability to adjust their cropping systems for even higher productivity and more income, sparking changes analogous to that of the first green revolution, which previously benefited only favorable irrigated and rainfed areas. New breeding tools using markers for multiple stresses made it possible to develop more resilient, higher yielding varieties to replace the aging and obsolete varieties still dominating these areas. Varieties with multiple stress tolerances are now becoming available, providing even better security for farmers and lessening their production risks even in areas affected by complex and overlapping stresses. The progress made in these less favorable areas triggered numerous favorable changes at the national and regional levels in several countries in Asia, including adjusting breeding and dissemination strategies to accelerate outreach and enabling changes at higher policy levels, creating a positive environment for faster progress. Exploiting the potential of these less productive areas for food production is inevitable, to meet the escalating global needs for more food and sustained production systems, at times when national resources are shrinking while demand for food is mounting. However, the success in these areas requires concerted efforts to make use of existing genetic resources for crop improvement and establishing effective evaluation networks, seed production systems, and seed delivery systems to ensure faster outreach and transformation.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.2
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• pp.152-163
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• 2007

The on-going pre-environmental investigation at present is performed by separate numerical analysis of each provision which makes integrated pre-environmental investigation is difficult. The application of numerical data is insufficient, which results to the deterioration of environmental investigation result's objectivity. A lot of time and money is required for the investigation. In this study, the spacial analysis function of GIS was applied on the 8 pre-environmental investigation factors. Pre-environmental investigation GIS DMS(Decision Making System) using AHP was constructed to make integrated investigation possible through the use of investigation results for each factor. Through the use of the developed pre-environmental investigation GIS DMS and the pre-constructed GIS data, the objectivity of environmental investigation is sufficient and time and cost are reduced. Therefore, this system can be used for pre-environmental investigation during route selection in the initial stages of road construction. Through the numerical and visual data obtained from the system developed in this paper, it is easier to gain the approval of the public. Furthermore, environmental problems due to road construction can be investigated with less time and money during the initial stages of road construction.

• Journal of the Korean association of regional geographers
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• v.15 no.6
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• pp.752-762
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• 2009

This paper aims to investigate the characteristics of location and business-services networks of venture firms in Daegu region. The regional venture firms are small scale and consist of mainly R&D investment and license new-technology in the category of soft-ware. Since the mid-1990's the firms that were founded by people with higher education and career experience seek diverse growth strategies. those firms concentrate in some regions of dalseo-gu and buk-gu. There are a few difference by types of firm-business, but, on the whole, the princepal location factors of venture firms are accessibility of research institute and university, easy information availability, and use of moderate land. In regard to networks with client firms, the venture firms determine whether to transfer. The result of the characteristics of networks between regional venture firms and business-service enterprises is as follows; the regional venture firms utilize small number of business-service enterprises and use mainly information processing and other computer operation related services and professional, scientific and technical services. In business-service be used by regional venture firms, the frequency of information processing and other computer operation related services, research and development, business support services is much, while the frequency of professional, scientific and technical services is little. Business-service enterprises are distributed mostly in Daegu region and are used owing to lack of technology and knowledge.

• Journal of Cadastre & Land InformatiX
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• v.48 no.2
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• pp.197-211
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• 2018

We conducted this research to examine how well regional housing prices are suited to use as an alternative to conventional census-based regional deprivation indices in health and medical geography studies. To examine the relative performance of mean regional housing prices compared to conventional census-based regional deprivation indices, we compared several multilevel logistic regression models, where the first level was individuals and the second was health districts in the Seoul Metropolitan Area (SMA) in Korea, for the sake of adjusting the regional clustering tendency of unknown factors. In these models, we predicted two dichotomous variables that represented individuals' after-lunch tooth brushing behavior and use of dental floss by individual characteristics and regional indices. Then, we compared the relative predictive performance of the models using the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). The results from the estimations showed that mean regional housing prices and census-based deprivation indices were correlated with the two types of dental health behavior in a statistical sense. The results also revealed that the model with mean regional housing prices showed smaller AIC and BIC compared with other models with conventional census-based deprivation indices. These results imply that it is possible for housing prices summarized using aerial units to be used as an alternative to conventional census-based deprivation indices when the census variables employed cannot properly reflect the characteristics of the aerial units.

• Journal of Life Science
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• v.31 no.6
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• pp.587-594
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• 2021

By 2050, 70% more food will be needed to fulfill the demands of a growing population. Among the solutions, cultured meat or clean meat is presented as a sustainable alternative for consumers. Scientists have begun to leverage knowledge and tools accumulated in the fields of stem cell and tissue engineering in efforts aimed at the development of cell-based meat. Cultured meat has to recreate the complex structure of livestock muscles with a few cells. Cells start to divide after they are cultured in a culture medium, which provides nutrients, hormones, and growth factors. An initial problem with this type of culture is the serum used, as in vitro meat aims to be slaughter free. Thus, it is contradictory to use a medium made from the blood of dead calves. The serum is expensive and affects to a large extent the production cost of the meat. A positive aspect related to the safety of cultured meat is that it is not produced from animals raised in confined spaces and slaughtered in inhumane conditions. Thus, the risk of an outbreak is eliminated, and there is no need for vaccinations and animal welfare issues. The production of cultured meat is presented as environmentally friendly, as it is supposed to produce less greenhouse gas, consume less water, and use less land in comparison to conventional meat production.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.979-989
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• 2022

In hydrological surveys, observation through representative location is essential due to temporal and spatial limitations and constraints. Regarding the use of hydrological data and the accuracy of the data, there are still insufficient observatories to be used in a specific watershed. In addition, since there is virtually no standard for the location of the current evapotranspiration, this study proposes a method for determining the location of the evapotranspiration. To determining the location of evapotranspiration, a grid is selected in consideration of the operating range of the Flux Tower using the eddy covariance measurement method, which is mainly used to measure evapotranspiration. The grid of representative location was calculated using the factors affecting evapotranspiration and satellite data of evapotranspiration. The grid of representative location was classified as good, fair, and poor. As a result, the number of good grids calculated was 54. It is judged that the classification of the grid has been achieved regarding topography and land use as a characteristic that appeared in the classification of the grid. In particular, in the case of elevation or city area, there was a large deviation, and the calculated good grid was judged to be a group between the two distributions.

• Korean Journal of Ecology and Environment
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• v.49 no.3
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• pp.197-207
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• 2016

This study aims at providing basic data to objectively evaluate the areas suitable for reintroduction of the species of Asiatic black bear (Ursus thibetanus) in order to effectively preserve the Asiatic black bears in the Korean protection areas including national parks, and for the species restoration success. To this end, this study predicted the potential habitats in East Asia, Southeast Asia and India, where there are the records of Asiatic black bears' appearances using the Maxent model and environmental variables related with climate, topography, road and land use. In addition, this study evaluated the effects of the relevant climate and environmental variables. This study also analyzed inhabitation range area suitable for Asiatic black and geographic change according to future climate change. As for the judgment accuracy of the Maxent model widely utilized for habitat distribution research of wildlife for preservation, AUC value was calculated as 0.893 (sd=0.121). This was useful in predicting Asiatic black bears' potential habitat and evaluate the habitat change characteristics according to future climate change. Compare to the distribution map of Asiatic black bears evaluated by IUCN, Habitat suitability by the Maxent model were regionally diverse in extant areas and low in the extinct areas from IUCN map. This can be the result reflecting the regional difference in the environmental conditions where Asiatic black bears inhabit. As for the environment affecting the potential habitat distribution of Asiatic black bears, inhabitation rate was the highest, according to land coverage type, compared to climate, topography and artificial factors like distance from road. Especially, the area of deciduous broadleaf forest was predicted to be preferred, in comparison with other land coverage types. Annual mean precipitation and the precipitation during the driest period were projected to affect more than temperature's annual range, and the inhabitation possibility was higher, as distance was farther from road. The reason is that Asiatic black bears are conjectured to prefer more stable area without human's intervention, as well as prey resource. The inhabitation range was predicted to be expanded gradually to the southern part of India, China's southeast coast and adjacent inland area, and Vietnam, Laos and Malaysia in the eastern coastal areas of Southeast Asia. The following areas are forecast to be the core areas, where Asiatic black bears can inhabit in the Asian region: Jeonnam, Jeonbuk and Gangwon areas in South Korea, Kyushu, Chugoku, Shikoku, Chubu, Kanto and Tohoku's border area in Japan, and Jiangxi, Zhejiang and Fujian border area in China. This study is expected to be used as basic data for the preservation and efficient management of Asiatic black bear's habitat, artificially introduced individual bear's release area selection, and the management of collision zones with humans.