• Journal of Cadastre & Land InformatiX
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• v.51 no.1
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• pp.97-110
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• 2021

This study estimated the delay factor, which is the ratio of travel time at the speed limit and travel time at the actual speed using real-time traffic information in Seoul. The actual travel speed on the road was lower than the maximum speed of the road and the travel speed was the slowest during the rush hour. As a result of accessibility analysis based on travel speed during the rush hour, the travel time at the actual speed was 37.49 minutes on average. However, the travel time at the speed limit was 15.70 minutes on average. This result indicated that the travel time at the actual speed is 2.4 times longer than that at the speed limit. In addition, this study proposedly defined the delay factor as the ratio of accessibility by the speed limit and accessibility to actual travel speed. As a result of delay factor analysis, the delay factor of Seoul was 2.44. The results by the administrative district showed that the delay factor in the north part areas of the Han River is higher than her south part areas. Analysis results after applying the relationship between road density and traffic volume showed that as the traffic volume with road density increased, the delay factor decreased. These results indicated that it could not be said that heavy traffic caused longer travel time. Therefore, follow-up research is needed based on more detailed information such as road system shape, road width, and signal system for finding the exact cause of increased travel time.

• Journal of Advanced Navigation Technology
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• v.28 no.1
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• pp.102-108
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• 2024

In the initial stages of urban air mobility (UAM) operations, compliance with existing visual flight rules and instrument flight regulations for conventional human-crewed aircraft is crucial. Additionally, voice communication between the on board pilot and relevant UAM stakeholders, including vertiports, is essential. Consequently, very high frequency (VHF) aviation voice communication must be consistently provided throughout all phases of UAM operations. This paper presents the results of the VHF communication coverage analysis for the initial UAM demonstration areas, encompassing the Hangang River and Incheon Ara-Canal corridors, as well as potential vertiport candidate locations. By considering the influence of terrain and buildings through the utilization of a digital surface model (DSM), communication quality prediction results are obtained for the analysis areas. The three-dimensional coverage analysis results indicate that stable coverage can be achieved within altitude corridors ranging from 300 m to 600 m. However, there are shaded areas in the low-altitude vertiport regions due to the impact of high-rise buildings. Therefore, additional research to ensure stable coverage around vertiports in the lower altitude areas is required.

• Particle and aerosol research
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• v.19 no.4
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• pp.111-128
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• 2023

Chungcheongnam-do has various emission sources, including large-scale facilities such as power plants, steel and petrochemical industry complexes, which can lead to the severe PM pollution. Here, we measured concentrations of PM₁₀, PM_2.5, and its metallic elements at a suburban site in Taean, Chungcheongnam-do from September 2017 to June 2022. During the measurement period, the average concentrations of PM₁₀ and PM_2.5 were 58.6 ㎍/m³ (9.6~379.0 ㎍/m³) and 35.0 ㎍/m³ (6.1~132.2 ㎍/m³), respectively. The concentration of PM₁₀ and PM_2.5 showed typical seasonal variation, with higher concentration in winter and lower concentration in summer. When high concentrations of PM_2.5 occurred, particulary in winter, the fraction of Zn and Pb components considerably increased, indicating a significant contribution of Zn and Pb to high-PM_2.5 concentration. In addition, Zn and Pb exhibited the highest correlation coefficient among all other metallic elements of PM_2.5. A backward trajectory cluster analysis and CPF model were performed to examine the origin of PM_2.5. The high concentration of PM_2.5 was primarily influenced by emissions from industrial complexes located in the northeast and northwest areas.

• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.723-734
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• 2010

This study aims to analyze the change in vegetation for 10 years after the construction, targeting Suwoncheon, the first domestic ecological stream construction project. As for the section for the study, the section from Gyeonggi bridge to Youngyeon bridge, the first restoration project section, was targeted. The research districts consisted of 3 districts depending on topographical structure. Investigation check cosisted of cross-sectional topographical structure, vegetation status and the structure of herbaceous plant community. As for the cross-sectional topographical structure of the stream, the width of entire stream was 26.5~28.0m and water channel is 10~20m. The area for hydrophilic space was securing spacious riverside. Upper stream of reservoir beam was shallow and slow in reservoir area above weir. Lower stream of reservoir beam, the width of water channel was narrow and ripples were formed. Among species, 9 plants were planted and 6 species plants including Salix gracilistyla, Phragmites communis and Zoysia japonica were planted at the time of construction. In the water side, there were 2 species, such as Zoysia japonica and Trifolium repens, etc, still remained after seeding at the time of constrcution. The planted plants which were observed through this investigation, were 2 species such as Festuca arundinacea and Dactylis glomerata. Apart from the planted plants, arid climate herbaceous plant such as Setaria viridis and Artemisia princeps var. orientalis formed power and the naturalized species variously emerged in 15 species. For revetment, natural stone stacking method was condicted and Salix gracilistyla, Aceriphyllum rossii, etc were planted. But all the planted plants disappeared and now it was covered with Equisetum arvense and Humulus japonicus. It was because that the base for growth and development of the plants was not constructed at the time of restoration in a way of attaching natural stones onto the concrete base. In the water channel, various wetland species including Typha orientalis, Acorus calamus var. angustatus and Phragmites communis, etc, were planted but only Salix gracilistyla, Phragmites communis and Zizania latifolia remained. As for species of the autochthons, Persicaria thunbergii was dominant. In the lower stream of reservoir beam, Humulus japonicus formed forces. In the hydrophilic space, it was necessary to direct the landscape of in-stream vegetation in cosideration of users. For this, planting Miscanthus sacchariflorus in a community was proposed. In the upper stream of reservoir beam, suplementary screen seeding was necessary so that Zizania latifolia, Typha orientalis and Phragmites communis can fit the depth of water. In the Lower stream of reservoir beam, it was necessary to constantly manage Humulus japonicus so that the wetland autochthons species, such as Phragmites communis and Persicaria thunbergii can establish power more stably.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.31-39
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• 2002

Pollutants from industry, mining, agriculture, and other sources have contaminated sediments in many surface water bodies. Sediment contamination poses a severe threat to human health and environment because many toxic contaminants that are barely detectable in the water column can accumulate in sediments at much higher levels. The purpose of this study was to make optimal treatment and disposal plan o( sediment for water quality improvement in small-scale resevoir based on an evaluation of degree of contamination. The degree of contamination were investigated for 23 samples of 9 site at different depth of sediment in small-scale J river. Results for analysis of contaminated sediments were observed that copper concentration of 4 samples were higher than the regulation of hazardous waste (3 mg/L) and that of all samples were exceeded soil pollution warning levels for agricultural areas. Lead and mercury concentration of all samples were detected below both regulations. Necessary of sediment dredge was evaluated for organic matter and nutrient through standard levels of Paldang lake and the lower Han river in Korea and Tokyo bay and Yokohama bay in Japan. The degree of contamination for organic matter and nutrient was not serious. Compared standard levels of Japan, America, and Canada for heavy metal, contaminated sediment was concluded as lowest effect level or limit of tolerance level because standard levels of America and Canada was established worst effect of benthic organisms. The optimal treatment method of sediment contained heavy metal was cement-based solidification/stabilization to prevent heavy metal leaching.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.6
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• pp.27-36
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• 2021

At a time when the equitable use of urban parks is gradually emerging as a social issue, this study was initiated to expand the influence of urban parks by improving the quality of park services, thereby resolving areas not covered by urban park services. This study targeted the Hangang Park in Seoul, where the qualitative service of parks shows the greatest difference. The influence relationship between the qualitative services of the park and the user's sphere of influence, which indicates the distribution of park users, was proposed to assess the influence of improvements in the quality of service. As a research method, the top three districts and the bottom three districts were selected through the Han River Park user satisfaction survey conducted from 2017 to 2019, and a qualitative service evaluation was carried out. It was derived using the data acquired in September. Afterward, by performing a spatial autocorrelation analysis on the user's sphere of influence, additional verification of the user's sphere of influence was performed numerically and visually. As a result of the study, the user influence in the top three districts, with high-quality service, was stronger and wider than that of the lower three districts. It was confirmed that the quality of service of the park affects the user influence. This shows that to realize park equity, it is necessary to improve the quality of services through continuous management and improvement of individual parks and the creation of new parks. This study has significance in that it recognizes the limitations of research on park services from a supplier's point of view and evaluates the qualitative services of parks from the perspective of actual park users. We propose an alternative to deal with the lower the park deprivation index.

• Journal of Korean Society of Forest Science
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• v.54 no.1
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• pp.1-24
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• 1981

Kangweon-Do is rich in sightseeing resources. There are three sightseeing areas;first, mountain area including Seolak and Ohdae National Parks, and chiak Provincial Park; second eastern coastal area; third lake area including the watersheds of North Han River. In this paper, several methods of forestation were studied for landscaping the North Han River watersheds centering around Chounchon. In Chunchon lake complex, there are four lakes; Uiam, Chunchon, Soyang and Paro from down to upper stream. The total surface area of the above four lakes is $14.4km^2$ the total pondage of them 4,155 million $m^3$, the total generation of electric power of them 410 thousand Kw, and the total forest area bordering on them $1,208km^2$. The bordering forest consists of planned management forest ($745km^2$) and non-planned management forest ($463km^2$). The latter is divided into green belt zone, natural conservation area, and protection forest. The forest in green belt amounts to $177km^2$ and centers around the 10km radios from Chunchon. The forest in natural conservation area amounts to $165km^2$, which is established within 2km sight range from the Soyang-lake sides. Protection forest surrounding the lakes is $121km^2$ There are many scenic places, recreation gardens, cultural goods and ruins in this lake complex, which are the same good tourist resources as lakes and forest. The forest encirelng the lakes has the poor average growing stock of $15m^3/ha$, because 70% of the forest consists of the young plantation of 1 to 2 age class. The ration of the needle-leaved forest, the broad-leaved forest and the mixed forest in 35:37:28. From the standpoint of ownership, the forest consists of national forest (36%), provincial forest (14%), Gun forest (5%) and private forest(45%). The greater part of the forest soil, originated from granite and gneiss, is much liable to weathering. Because the surface soil is mostly sterile, the fertilization for improving the soil quality is strongly urged. Considering the above-mentioned, the forestation methods for improving landscape of the North Han River Watersheds are suggested as follows: 1) The mature-stage forest should be induced by means of fertilizing and tendering, as the forest in this area is the young plantation with poor soil. 2) The bare land should be afforested by planting the rapid growing species, such as rigida pine, alder, and etc. 3) The bare land in the canyon with moderate moist and comparatively rich soil should be planted with Korean-pine, larch, ro fir. 4) Japaness-pine stand should be changed into Korean-pine, fir, spruce or hemlock stand from ravine to top gradually, because the Japanese-pine has poor capacity of water conservation and great liability to pine gall midge. 5) Present hard-wood forest, consisting of miscellaneous trees comparatively less valuable from the point of wood quality and scenerity, should be change into oak, maple, fraxinus-rhynchophylla, birch or juglan stand which is comparatively more valuable. 6) In the mountain foot within the sight-range, stands should be established with such species as cherry, weeping willow, white poplar, machilus, maiden-hair tree, juniper, chestnut or apricot. 7) The regeneration of some broad-leaved forests should be induced to the middle forest type, leading to the harmonious arrangement of the two storied forest and the coppice. 8) For the preservation of scenery, the reproduction of the soft-wood forest should be done under the selection method or the shelter-wood system. 9) Mixed forest should be regenerated under the middle forest system with upper needle-leaved forest and lower broad-leaved forest. In brief, the nature's mysteriousness should be conserved by combining the womanly elegance of the lakes and the manly grandeur of the forest.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.3
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• pp.265-275
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• 1985

Present studies were carried out to investigate the distribution and formation of organic tiers contained paddy soils in Honam area characteristics to give basic informations on the effective utilization, management and improvement of the soils. The results obtained were summarized as follows; 1. The extent of organic tiers contained paddy soils in Honam area were 6.538㏊ and the amount of peat deposits were presumed about 2.41 million M/T. 2. Out of the total extent of the organic tiers contained paddy soils, about 97.6% was distributed in Honam plains (water-sheds of Mangyeong-Dongjin river), while about 1.5% in the Naju plains (water-sheds of Yeongsan river), and 0.9% in the Wando and Yeocheon areas. 3. The period of peat formation was presumed to be about the early of Seung Moon period (B.C. 4,250), and the Gongdeog series and the Bongnam series were formed in the bog conditions close to the valley mouth of near rolling and hill with small steram channels, and the Gimje series was formed in the out-skirts plains of the Gongdeog and Bongnam soils. 4. In the casue of peat formation, it was presumed to be the Gimje series that accumulated the fibrous peat out of the autochthonous peat such as reeds and grasses etc, to be the Gongdeog and Bongnam series that accumulated the autochtonous peat and the xylem and fibrous peat out of first allochthonous peat. 5. In the Organic horizons of these soils, the range of muck and peat horizons were in 62-68cm and 68-137cm of soil profile in the Gongdeog series, 52-84cm and 84-113cm in the Bongnam series respectively, one of muck horizon was in 46-71cm in the Gimje series. 6. The marks of soil horizons of the soils were expressed that the lower soils than the horizon of muck and peat were formed Cg, Aag for the muck horizon, 0 for the peat horizon, 0 of peat horizon were distingushed with Oag and Oig according to Organic forms. 7. The depthe occurred the muck and peat horizons were positively correlated with the width of local in the Gongdeog series ($r=0.881^{**}$, $r=0.827^{**}$), but not in the Bongnam series and Gimje series.

• Korean Journal of Health Education and Promotion
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• v.18 no.3
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• pp.133-162
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• 2001

Unexpected accidents in school has been gradually increased every year, and student's mistaken was the first reason of the accident. To preventing the students from Unexpected accidents in school, safety education is more important than having strong facilities to have much more strong protecting forces for the accidents. Therefore, systematic education of safety is needed most of all, and especially, strengthening safety education in school is needed. Hereby, this study is aimed at investigating and analysing the actual condition and demand of safety education. It also conducted a survey with the target of 1,255 students in the second grade of high school in Seoul from April 20 to May 19, and the result of this study is as follows. 1. In the general features of the subject of the survey, boy students and girl students occupied 50.8％ and 49.2％ each, and boys' high school (34.3％), girls' high school(32.2％) and co-ed(33.5％) participated in balance. In the location, north from Han river occupied 54.6％, south were 45.2％. 2. According to the status of experiencing an accident, boys were more experienced then girls(p〈0.05). From the section, home accident(56.8％) occupied most followed by school accident, traffic accident, sports accident and poisoning. The accident happening most often in detailed category is sports accident such as basket ball, foot ball and dodge ball. The actual condition of the subject's using a school health facility shows that boys students use it more often than girl students(p〈0.01) 3. In attitude toward safety, the subject showed lower interest in safety issues than other social issues. But attitude in seriality of safety problems were high. Also, they responded ‘individual citizen’(63.1％) as the one who should make efforts for safety. Regarding knowledge of preventing safety accidents in attitude toward individual safety, 42.2％ answered ‘they know a little’ and 32.6％ of respondents say ‘they do not know’. To a question of the degree of the subject's following safety rules, 36.4％ were answered ‘keeping’ and the group using a school health facility shows more ‘keeping’ the others(p〈0.05). 4. To a question of asking if they have experienced safety education, 51.2％ answered ‘yes’. Teachers who mainly take care of safety education are answered as training teacher(48.7％). As for education time, training class(51.3％) is said to have safety education most followed by health-related event and PE(Physical Education). Frequency of education shows once or twice a session (62.8％) most often, but in case of co-ed school, 5-7times a session or more(20.1％) are being practiced. Looking at education time, 1-2 hour(s)(22.1％) or for a short time(22.1％) during class are being practiced. As an education method, instruction(43.8％) and video education(32.5％) are being practiced, and when it comes to education evaluation method, ‘not practiced’(70.0％) answered. To the question if they are satisfied with school safety education, they answered more ‘no(43.1％)’ than ‘yes(6.7％)’, and the reason is that safety education class is just for formality's sake, and the fact they already know is being repeated. The contents of safety education is composed of school safety, home safety, and first aid. 5. It is turned out that 56.5％ of the total boy students and 61.1％ of the total girl students recognize the necessity of safety education. To the question if safety education is needed in an elementary and middle education course, 46.4％ of the subject answer answered' it's necessary'. The most reason for their answers are ‘safety education is directly related to life’. 6. Regarding the requested time of safety education is ‘one hour a week’ by 55.9％. For safety education, safety education teachers(38.7％) are answered to be the most proper. As a request for safety education, video education is answered to be the most appropriate(30.6％), followed by practical skills, lecture and discussion(p〈0.05). Demand of educational evaluation, practical skills, interview and observation are answered to be needed. To the question if they want to participate in the way of demanded safety education, 41.9％ of respondents answer ‘have a mind to participate in’ (41.9％). To benefits followed by completing safety education, 72.0％ of respondents answer ‘agree’, and 24.7％ ‘do not agree’, which means lout 4 disagrees with completing safety education. 7. Looking at demand of safety education according to the features of the subject, ‘our position for the person who has handicapped’ was answer to the most.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.1
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• pp.18-27
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• 2009

The purpose of this study is to understand the scale of temperature change following large-scale urban developments in paddy fields to present possible measures to preserve suburban area paddy fields and to lower the scale of temperature increase after developing paddy fields in urban areas. The study was conducted in Bupyeong and Bucheon of Incheon Metropolitan City. The satellite image($1989{\sim}2000$) before and after the development of old paddy fields were used to analyze the land surface temperature changes according to the land use types. Building coverage, green coverage, non-permeable pavement coverage, and floor area ratio(FAR) were selected as the factors that influence urban temperature changes and the temperature estimation model was constructed by using correlation and regression analyses. The before and after satellite images of Bupyeong and Bucheon were classified into forests, greens and plantations, paddy fields, unused lands, and urban areas. The results indicate that most of the paddy fields that existed in the center of Bupyeong and Bucheon were converted into unused lands which were undergoing construction to become new urban areas. The difference between the surface temperatures of May 17th, 1989 and May 7th, 2000 was analyzed to reveal that most land converted from paddy fields to unused lands or urban areas saw an increase in surface temperature. Han River was used as a comparison to analyze the average surface temperature changes($1989{\sim}2000$) in former paddy fields. The scale of temperature changes were: $+1.6697^{\circ}C$ in urban parks; $+2.5503^{\circ}C$ in residential zones; $+2.9479^{\circ}C$ on public lands, $+3.0385^{\circ}C$ in commercial zones, and $+3.1803^{\circ}C$ in educational zones. The correlation between building coverage, green coverage, non-permeable pavement coverage, or floor area ratio(FAR) and surface temperature increases was also analyzed. The green coverage to temperature increases, but building coverage, non-permeable pavement coverage, and floor area ratio(FAR) had no statistically significant temperature increases. The factors that influence urban temperature changes were set up as independent variables and the surface temperature changes as dependent variables to construct a surface temperature change model for the land use types of former paddy fields. As a result of regression analysis, green coverage was selected as the most significant independent variable. According to regression analysis, if farmland is converted into an urban area, a temperature increase of $+3.889^{\circ}C$ is anticipated with 0% green coverage. The temperature saw a decrease of $-0.43^{\circ}C$ with every 10% increase of green coverage.