• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.22-34
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• 2004

An artificial disturbance like fragmentation in watershed forest has impacted a sustainability of watershed ecosystem, therefore this research quantified the landscape structure in the Geumho river watershed using landscape indices and GIS. Landscape indices were calculated from the forest distributed maps for 24 subwatersheds. Three common factors, which explained about 85% of the variation in the original data, were extracted by a factor analysis. The fragmentation gradient in forest landscape, which was calculated from the factor scores, was correlated with proportion of urban land (r=0.827, p<0.01, $R^2$=0.685), elevation (r=-0.637, p<0.01) and slope gradient (r=-0.593, p<0.01). The result of the study presented that the methodology and the values of landscape indices to assess the structural patterns of forest landscape for the Geumho river watershed management. Future research will be directed towards the detection of impacts of landscape patterns and their changes on the integrity of watershed environments.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.132-142
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• 2014

In this paper, we propose a traffic lights detection method using visual attention and spot-lights detection. To detect traffic lights in city streets at day and night time, the proposed method is used the structural form of a traffic lights such as colors, intensity, shape, textures. In general, traffic lights are installed at a position to increase the visibility of the drivers. The proposed method detects the candidate traffic lights regions using the top-down visual saliency model and spot-lights detect models. The visual saliency and spot-lights regions are positions of its difference from the neighboring locations in multiple features and multiple scales. For detecting traffic lights, by not using a color thresholding method, the proposed method can be applied to urban environments of variety changes in illumination and night times.

• 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.

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.50-61
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• 2020

Street trees are very important to urban environments as they can alleviate air pollution. However, when ozone is absorbed through the stomata, it can induce the formation of free radicals inside the tree, negatively affecting the vegetation. The present study investigated the Air Pollution Tolerance Index (APTI) of four major street tree species: Prunus yedoensis, Zelkova serrata, Chionanthus retusus, and Pinus densiflora. Two-year-old seedlings were placed in a phytotron and fumigated with 100 nL·L^-1 (ppb) ozone for 4 weeks, following which the ascorbic acid contents, chlorophyll contents, leaf pHs, and relative water contents were measured. There was no significant difference in the APTI of Prunus yedoensis and Zelkova serrata between the ozone and control treatments. By contrast, the ozone treatment caused the APTI of Chionanthus retusus to increase and that of Pinus densiflora to decrease compared with the respective controls. These results suggest that the APTI of these tree species exhibit very different responses to ozone. Therefore, more detailed research should be conducted on a range of species in the future.

• Journal of the Korean Society of School Health
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• v.12 no.2
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• pp.321-337
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• 1999

The purpose of this study was to obtain basic data for the prevention and control of adolescent back pain through analyzing connections between study environments and physical posture. The subjects were 960 male general high school students in the Chonju area and the data were collected by a self-reported questionnaire from Mar. 17 to Mar. 22, 1999. The collected data were analyzed by a frequency, chi-square and t-test using an SPSS program. The results are as follows; 1) The experience rate of back pain perceived by subjects was 67.5% and by each grade: 1st-27.5%, 2nd-35.4%, 3rd-37.1%. The relationship between grades and the experience of back pain didn't show any significant difference. 2) The causes of back pain perceived by subjects such as 'postures are not good' was 56.7%, 'sitting too much time in a chair' was 39.1%, and 'too severe exercise' was 32.4%. 27.8% had back pain first during the 3rd grade of middle school, and 23.9% had it first during the 1st grade of high school. 3) Intensity of subjects' back pain spread from 'moderate' at 49.6%, to 'severe' at 16.4%. Concerning the frequency of back pain, 58.6% said it was 'irregalar'. 4) Among interventions to deal with back pain: 'move by exercising my back or ask friends to beat my back' was 41.0%, 'just bear it' was 23.1%, and at home 'don't have 'any treatment' was ranked first, at 54.9%. 5) The relationship between subjects' general characteristics and back pain experiences: height (t=-1.99, P=.046), sitting/height (t=-2.61, P=.009), self-perceived condition of health (${\chi}^2=23.530$, P=.000), family history (${\chi}^2=43.903$, P=.000) showed significant difference, but the kinds of transportation, sleeping postures, sleeping method and smoking didn't show significant differences. 6) The relationship between subjects' learning environment and back pain experiences, the height of students' desk and chair showed significant difference (${\chi}^2=23.054$, P=.000), but the sitting time didn't show significant difference. 7) The relationship between the characteristics of subjects' physical postures and back pain experiences: standing postures (${\chi}^2=15.105$, P=.001), and sitting postures (${\chi}^2=20.264$X2, P=.001) showed significant difference, but lifting postures didn't show significant difference.

• Journal of Korean Society of Transportation
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• v.32 no.6
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• pp.638-650
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• 2014

The objective of this study is to identify the causes of pedestrian volume path to the destination by investigating the influential levels of regional and planning features in the central area of Seoul. Regional characteristics can be classified from the result of the analysis and through the spatial characteristics of pedestrian volume. For global scale analysis, Ordinary Least Squares (OLS) regression is used for the degree of influence of each characteristics to pedestrian volume. For the local scale, Geographically Weighted Regression (GWR) is used to identify regional influential factors with consideration for spatial differences. The results of OLS indicate that boroughs with transportation facilities, commercial business districts, universities, and planning features with education research facilities and planning facilities have a positive effect on pedestrian volume path to the destination. Correspondingly, transportation hubs and congested areas, commercial and business centers, and university towns and research facilities in the Seoul central area can be identified through the results of GWR. The results of this study can provide information with relevance to existing plans and policies about the importance of regional characteristics and spatial heterogeneity effects on pedestrian volume, as well as significance in the establishment of regional development plans.

• Journal of Preventive Medicine and Public Health
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• v.27 no.2 s.46
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• pp.175-185
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• 1994

In order to anticipate disease pattern and health problems of Koreans in the 1st part of 21st century (by the year 2020), transition of population characteristics, mortality and morbidity data during the last 30 years Koreans have experienced were reviewed. On the actual basis of epidemiologic transition process that has undergone during last 30 years since 1960 along with socioeconomic development and successful implementation of selective national health policies (family planning, medical insurance and etc.), following changes can be expected in the 21st century in Korea, under the assumption that the current rate of progress is maintained. The population of South Korea alone will be doubled the population of 1960 by the year 2013 : aged Population older than 65 years will be increased from 3.3% in 1960 to 11.4% in 2020 with increased average age of the population from 23.6 year in 1970 to 39.2 year in 2020; urban population from 28% in 1960 to 83% in 2005. GNP/capita has increased tremendously from U.S. $120 in 1970 to $6,749 in 1992, and the government estimated it would be 519,350 in 2010 and $29,460 in 2020. Growth and developmental indices of children, educational achievement and social status of women also showed a remarkable improvement and anticipated to make futher progress. Leading causes of mortality and morbidity have shown a striking change during the last 30 years, from infectious diseases to chronic degenerative diseases and man-made injuries. Occurrence of communicable diseases may become minimal although viral hepatitis, venereal diseases Including AIDS, and well adapted herpes virus infections will maintain their endemic level. Newly evolving infectious agents, however, should be carefully monitored because of rapidly changing environments and human behaviours. Tuberculosis may increase up to the epidemic level when AIDS prevails. Ischemic heart diseases may increase steadily with increasing occurrence of hypertension and diabetes mellitus whereas cerebrovascular diseases may be decreased slowly. Musculaskeletal diseases which contribute a lot to the disability of aged people may be a major health problems due to increased aged population. Mental diseases, particularly that caused by alcohol and drug abuse, and senile dementia may become a prominent health problem. On the other hand injuries caused by traffic and industrial accidents that have shown most striking increase till now may be decreased considerably by intensive intervention. The health policies in the 21st century will be oriented to the health promotion for good quality life rather than life-savings.

• International Journal of Highway Engineering
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• v.8 no.4 s.30
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• pp.37-47
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• 2006

The road sign is one of street furnitures functioning to guide directions for drivers. The road sign should be employed and designed to help drivers find their destinations easily and accurately. It is obvious that the road sign is one of the main components that enhance efficiency and safety of driving environments. The current way of guiding strategy at road signs in Korea is a system for mainly guiding 'points' although a new system guiding 'road names' and 'street numbers' with the introduction of new address system is now being introduced on urban areas. When the regional territory management offices and local governments try to employ current road sign systems, they are supposed to follow the sign regulations which contains standard project processes, selection methods of guiding points, character size and design, and location selection for each road sign. However, the current road sign regulations are very complex to understand and unclear for a person in charge to do tasks described above. Especially, selection process and criteria of guiding points are cumbersome and controversial. Furthermore, non sufficient ways of selecting guiding points considering road functions and geographic characteristics decrease the connectivity of guiding points. This study develops enhanced ways of increasing connectivity of successive guiding points through three case studies. Developed ways will help highway agencies and officials understand how to improve the connectivity of road signs.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.371-378
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• 2014

The subject of this study is the Gongchon-cheon which is one of the largest streams in Incheon and is closely related to lives of citizen. Comparative analysis is made on the changes of the environment and the ecological condition of Gongchon-cheon after the stream naturalization construction which is completed in July 2009. From the results of the survey, 32 species in 2004, 22 species in 2009 and 46 species in 2010 have been recorded. The number of the species decreased from 2004 to 2009 due to the disturbance of the river environment, and it increased in a short time from 2009 to 2010 because of the recovery of the environment. It demonstrates the stream naturalization construction providing enough environments (dikes and rapids) for the benthic macro invertebrates. The result of the present study is similar with the river's biology index, ESB index, and KSI index, and also it is similar with the pattern of the appearance, which illustrates that the species decreased during the naturalization construction, and increased after the stabilization since the finish of the naturalization construction, and it has been confirmed that the naturalization construction provides the better environment for the inhabitation of organisms.

• Journal of the Korean association of regional geographers
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• v.19 no.4
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• pp.668-682
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• 2013

This study illustrates the mechanism of The Decrease of Korean population in Yanbian Korean Autonomous Prefecture (YBKAP) and some changes of regional characteristics since China's economic reforming. Due to China's Implementing market economic system, deregulating in family register system, higher mobility since establishing Sino-Korean diplomatic relations, the expansion of intermarriages and residential areas, Korean community is confronted with lower birthrate and continuous mobility of the young and women. It directly connects to a decrease in urban population and aging, causing a decline in farming production, disintegrating of Korean community, weakening the function of villagers' organization, shrinking in Korean education and leaderships. For supplementing the shorted labor, Chinese farmers from other areas flow into the YBKAP, showing some different trends, such as farming Chinesization, Chinese farmers' higher economic level than Korean, the Korean traditional paddy field transforming into dry farmland with single-crop farming and pursuing commercial production in labor management. At the moment, declining population in Korean community in rural areas means that the community could not respond the changes of farming environments appropriately and in some way it is facing with the crisis of die away from the Chinese society. It needs an unconventional support and development policies in YBKAP rural areas.