• Horticultural Science & Technology
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• v.17 no.4
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• pp.500-502
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• 1999

This study was carried out to survey the distribution of Korean native Sedum rotundifolium and environmental conditions of their native habitats. Sedum rotundifolium could be found only at the Mt. Juwang and its vicinity, Okgae valley. And most of Sedum rotundifolium plants in habitats were positioned between the chasm of cliffs in middle mountainous area having altitudes ranging about 250~450 m. Most of soil conditions in native habitats were somewhat arid, and light intensities were ranged from 1 to 90 % of those at the open area. But relative humidity, air temperature and soil temperature showed little difference compared with those of open area. Soil acidities were ranged from pH 5.0 to 7.0, and relatively high amount of humus, total $P_2O_5$, Ca, and Mg were measured at habitat area. On the other hand, growth of Sedum rotundifolium was significantly different according to habitat sites.

• Journal of Environmental Impact Assessment
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• v.19 no.3
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• pp.271-279
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• 2010

We conducted a quantitative human health risk assessment with respect to inhalation of heavy metals for residents of housing developments in "new towns" where an incinerator will be operated within the area scheduled for construction thereof. To assess potential human health risk we calculated the amount of heavy metals emitted from the incinerator, and then forecasted the potential health impact on adjoining areas where new housing is to be developed (i.e. "new towns") at different altitudes by a using SCREEN-3 model. We assessed Cancer Risk (CR) caused by known carcinogens using the Inhalation Unit Risk criteria developed by the US Environmental Protection Agency. Notably, we assessed risk by determining concentrations of heavy metals on a floor by floor basis, as apartment buildings are to be constructed near the incinerator according to a pre-devised plan. Results indicated that cancer risk for most carcinogens exceeded US EPA standards for the highest locations at each collection point. This result indicates that construction of high buildings in areas adjoining incinerators is undesirable, and that measures to lower carcinogens are needed. The results of this study, which assessed health risk from exposure to heavy metals emitted from a nearby incinerator, can be useful in land use planning with respect to the location of housing developments in new towns, as well as the heights of any buildings constructed. Furthermore, the methodology deployed herein with respect to risk assessment can be helpful for policy makers and the general public in the event of conflicts regarding incinerator projects in the future. The results herein may also be of merit in determining priorities when establishing harm reduction measures for carcinogens at incinerators. However, the study does contain several limitations. The SCREEN-3 model, a kind of screening model that provides conservative results, can provide higher forecasted concentrations of air pollutants than other models. Moreover, although the incinerator in question is set to be a thermoselect type, domestic data for emissions from these incinerators is not available, and assumptions were based on a stoker type incinerator. Insufficient domestic data likewise compelled the use of data of USA, resulting in possible errors in results. Continued research will thus be required to develop systematic methodologies that address the foregoing factors and produce more reliable outcomes.

• Atmosphere
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• v.27 no.3
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• pp.359-370
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• 2017

In this study, the oceanic Total Precipitable Water (TPW) retrieval algorithm at 16 km altitude of High Altitude Long Endurance Unmanned Aerial Vehicle (HALE UAV) is described. Empirical equation based on Wentz method (1995) that uses the 18.7 and 22.235 GHz channels is developed using the simulated brightness temperature and SeeBor training dataset. To do radiative simulation, Satellite Data Simulator Unit (SDSU) Radiative Transfer Model (RTM) is used. The data of 60% (523) and 40% (349) in the SeeBor training dataset are used to develop and validate the TPW retrieval algorithm, respectively. The range of coefficients for the TPW retrieval at the altitude of 3~18 km with 3 km interval were 153.69~199.87 (${\alpha}$), 54.330~58.468 (${\beta}$), and 84.519~93.484 (${\gamma}$). The bias and RMSE at each altitude were found to be about $-0.81kg\;m^{-2}$ and $2.17kg\;m^{-2}$, respectively. Correlation coefficients were more than 0.9. Radiosonde observation has been generally operated over land. To validate the accuracy of the oceanic TPW retrieval algorithm, observation data from the Korea Meteorological Administration (KMA) Gisang 1 research vessel about six clear sky cases representing spring, autumn, and summer season is used. Difference between retrieved and observed TPW at 16 km altitude were in the range of $0.53{\sim}1.87kg\;m^{-2}$, which is reasonable for most applications. Difference in TPW between retrieval and observation at each altitude (3~15 km) is also presented. Differences of TPW at altitudes more than 6 km were $0.3{\sim}1.9kg\;m^{-2}$. Retrieved TPW at 3 km altitude was smaller than upper level with a difference of $-0.25{\sim}0.75kg\;m^{-2}$ compared to the observed TPW.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.1
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• pp.63-73
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• 2014

Recently, researches on DBRN(DataBase Referenced Navigation) system are being carried out to replace GNSS(Global Navigation Satellite System), as weaknesses of GNSS were found that are caused by the intentional interference and the jamming of the satellite signal. This paper describes the gravity gradient modeling and the construction of EKF(Extended Kalman Filter) based GGRN(Gravity Gradient Referenced Navigation). To analyze the performance of GGRN, fourteen flight trajectories were made for simulations over whole South Korea. During the simulations, we considered the errors in both DB(DataBase) and sensor as well as the flight altitudes. Accurate performances were found, when errors in the DB and the sensor are small and they located at lower altitude. For comparative evaluation, the traditional TRN(Terrain Referenced Navigation) was also developed and performances were analyzed relative to those from the GGRN. In fact, most of GGRN performed better in low altitude, but both of precise gravity gradient DB and gradiometer were required to obtain similar level of precisions at the high altitude. In the future, additional tests and evaluations on the GGRN need to be performed to investigate on more factors such as DB resolution, flight speed, and the update rate.

• Journal of the Korean earth science society
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• v.25 no.4
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• pp.214-221
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• 2004

The purpose of this study is to inquire into the effects of teaching methods in the class on the conceptual change of atmospheric pressure for middle school students. After analyzing the concept of atmospheric pressure in the middle school science textbooks on the present 7th Curriculum, classes were performed adopting classified Method A and Method 3. For Method A, the textbook is used to explain the concept in the view of weight. For Method B, the textbook is used to approach the concept in the views of molecular movement as well as of weight. This study consists of four classes in the third grade students of middle school in Busan, where they were divided into the Method A group and the Method B group. These study was carried out with pre-post on each of these classes on the learning achievement and on the conceptual change of atmospheric pressure. The results of this study were as follows: First, the effect on the learning achievement was displayed the average score of the Method B was showing a meaningful difference comparing to the Method A. Second, the effect on the conceptual change measured by verifying the score for the difference among the averages for each sub-scale three out of four conceptual factors,'the direction of atmospheric influence and the reason','the principle of atmospheric action' and 'the atmospheric changes by the temperature rise on the surface of the earth and the reason', showed meaningful improvement. But, the one left factor,'the distribution of atmospheric pressure by altitudes and the reason', displayed no meaningful difference. Third, The concept of atmospheric pressure is better defined as the pressure created by the movement of air particles, in the view of kinetic theory of gas, rather than explained by the notion of the weight of air.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.552-563
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• 2000

The aim of this study was to characterize the forest vegetation and site of Odaesan National Park for ecological forest management. The vegetation could be divided into two forest community groups, seven forest communities, and several subcommunities. South exposed, dry slopes were covered with forests of the Quercus mongolica-Acer pseudosieboldianum community group. Quercus mongolica-Acer pseudosieboldianum community group could be subdivided into ${\bullet}$ Rhododendron mucronulatum var. ciliatum community on dry sites, especially on south or south-westly exposed ridges or convex slopes; ${\bullet}$ Lespedeza${\times}$tomentella community on south exposed slopes, at low altitudes in the eastern part of the study area; ${\bullet}$ Carex humilis-Maackia amurensis community on south exposed slopes up to the montane region; ${\bullet}$ Quercus mongolica-Acer pseudo-sieboldianum typical community on south exposed middle and low slopes, and on upper and middle north exposed slopes; ${\bullet}$ Pimpinella brachycarpa community, preferably on moderately moist and cool sites. On north exposed, more humid and moist sites, forests of the Dryopteris crassirhizoma-Cornus controversa community group were found. This group was subdivided into ${\bullet}$ Acer tschonoskii var. rubripes-Acer tegmentosum community on moderately moist to moist, loamy soils on shady slopes; ${\bullet}$ Deutzia glabrata-Ulmus laciniata community on north exposed slopes with rocky soil and boulders, having high humidity. There are several rare and endangered species in Rhododendron mucronulatum var. ciliatum community, Carex humilis-Maackia amurensis community, Vicia venosa var. cuspidata subcommunity and Saxifraga punctata subcommunity, and the communities were located in azonal areas in topography. To protect the species, the areas should be categorized as an absolute conservation area, and any forest working should be prohibited in this area.

• 한국지구과학회:학술대회논문집
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• 2004.02a
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• pp.2-12
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• 2004

The purpose for this study is to inquire into the effects of teaching methods in the class on the conceptual change of atmospheric pressure for middle school students. After analyzing the concept of atmospheric pressure in the middle school science textbooks on the present 7th Curriculum, classes were performed adopting classified Method A and Method B. For Method A, the textbook used that explains the concept in the view of weight. For Method B, the textbook used approaching to the concept in the views of molecular movement as well as of weight. This study consists of four classes in the third grade students of middle school in Busan, which were divided into the Method A group and the Method B group. The result of the study carried out pre-post each of these classes on the learning achievement and on the conceptual change of atmospheric pressure. The result of this study were as follows: First, the effect on the learning achievement was displayed the average score of the Method B was showing meaningful difference comparing to the Method A. Second, the effect on the conceptual change measured by verifying the score for the difference among the averages for each sub-scale three out of four conceptual factors, 'the direction of atmospheric influence and the reason', 'the principle of atmospheric action' and 'the atmospheric changes by the temperature rise on the surface of the earth and the reason', showed meaningful improvement. But, the one left factor, 'the distribution of atmospheric pressure by altitudes and the reason', displayed no meaningful difference. Third, The concept of atmospheric pressure is better defined as the pressure created by the movement of air particles, in the view of kinetic theory of gas, rather than explained by the notion of the weight of air.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.363-372
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• 2001

The objective of this study was to investigate the site and growth characteristics of dominating Cornus controversa in the hardwood stands at Mt. Gariwang and Mt. Joongwang area located in Pyungchang-gun, Kangwon-do. The C. controversa was mainly distributed at the rather steep slope and aspect facing from northeast to northwest, and altitudes ranging from 800 to 1,100m. The C. controversa grew at relatively deep A soil layer with high moisture and nutrients. Major competing species in upper stories were Quercus mongolica, Acer mandshuricum, Salix hulteni, Acer pictum, and herb plants such as Polystichum tripteron, Dryopteris crassirhizoma, Meehania urticifolia, Pseudostellaria pahbiniana, Ligularia fischeri, Impatiens noli-tangere, Corydalis speciosa in the floor. The average annual diameter growth of C. controversa according to the altitude was $4.06({\pm}0.90)mm$ below 900m, $2.51({\pm}0.65)mm$ from 900 to 1,000m, $3.28({\pm}0.12)mm$ from 1,000m to 1,100m and $2.81({\pm}0.35)mm$ above 1,100m. Good annual growth was shown at northwest site, but no difference due to micro-topography.

• Journal of Radiation Protection and Research
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• v.29 no.2
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• pp.141-150
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• 2004

Dose rate characteristics of cosmic radiation field at flight altitudes were analyzed and the route doses to the personnels on board due to cosmic-ray were calculated for Korean-based commercial international airline routes using CARI-6. Annual individual doses to aircrew and the collective effective dose of passengers were estimated by applying the calculated route doses to the flight schedules of aircrew and the air travel statistics of Korea. The result shows that the annual doses to aircrew, around 2.62 mSv, exceed the annual dose limit of public and are comparable to doses of the group of workers occupationally exposed. Therefore it is necessary to consider the frequent flyers as well as the aircrew as the occupational exposure group. The annual collective dose to 11 million Korean passengers in 2001 appeared to be 136 man-Sv. The results should be modified when the dose rates of cosmic radiation at high altitude are revised by taking into account the changes in the radiation weighting factors for protons and neutrons as given in ICRP 92.

• Korean Journal of Environment and Ecology
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• v.20 no.2
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• pp.200-207
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• 2006

The objective of this study was to investigate the site and growth characteristics of Acer pictum var. mono growing in the deciduous stands at Mt. Joongwang area located in Pyungchanggun, Kangwon-do. A. pictum var. mono was mainly distributed at the rather steep slope and aspect facing from northeast to northwest, and altitudes ranging from 1,000 to 1,200m. It grew at relatively deep a soil layer with high moisture and nutrients. Major competing species in the upper stories were Betula costata, Acer mandshuricum, Quercus mongolica, Cornus controversa, and herb plants such as Meehania urtidfolia, Isodon excisus, Astilbe chinensis var. davidii, Dryopteris crassirhizoma and Ainsliaea acerifolia in the floor. The height growth was 0.25m in early time, decreased gradually and sustained growth of lower than 10cm. The diameter growth of A. pictum was under 1mm in early time, but increased to 0.3mm/yr and showed continuous growth of 2mm/yr recently. Annual volume growth showed rapid increased about age 120 and then showed stable growth, so the rotation period of A. pictum is expected more than 200 years without decay of heartwood.