• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.351-356
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• 2009

This study purposed to judge potential possibility of building highly precise empirical model using environmental variables. Environmental variables such as altitude, mean annual rainfall, mean annual temperature and organic matter ratio of soil were added to height and diameter model for Chamaecyparis obtusa, and examined accuracy and residuals of prediction model. Improvement in precision was found for the Gompertz polymorphic height model by including mean temperature and altitude as independent variables, while the Gompertz diameter model with annual rainfall and altitude was showed improvement of precision and accuracy. Comparing the improvement of precision between the model before adding environmental variables and the model after adding them, an improvement or some ratio was obtained though it is not obvious. Therefore, there is enough proof that adding environmental variables, which can be easily acquired relatively when considering the difficulties of measurement and budget, into the model as independent variables would improve the accuracy and precision of growth models.

• Journal of The Geomorphological Association of Korea
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• v.24 no.2
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• pp.79-90
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• 2017

This study investigated the correlation between the diatom community and the environmental variables on the tidal flat surface of the eastern part of Gomso Bay in the West coast of Korea in order to utilize the quantitative sea level record as a basic data. 24 sediment samples at 10cm intervals downstream of the Galgok Stream were used for diatom analysis, grain size analysis and CCA. As a result of diatom analysis, marine diatoms dominated at lower altitudes and the ratio of diatoms to fresh water diatoms and brackish diatoms increased toward upland. As a result of CCA, the contribution of environmental variables was analyzed as 25.3% at altitude, 21.6% at sand, 13.3% at skewness, etc. This means that altitude above sea level has the greatest influence on the diatom composition in the tidal flat surface. It suggests that the contribution of environmental variables at altitude above sea level can be used as a basic data for the quantitative records for reconstruction of paleo-sea level.

• Korean Journal of Environment and Ecology
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• v.27 no.4
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• pp.449-461
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• 2013

This study is contributed to examine the vegetation characteristics of the Quercus mongolica which are located in between two summits, hyangnobong and gitdaebaggybong, with dividing two regions(I, II). A total of 63 Quercus mongolica communities were enrolled in this survey. A~E, 5 communities were the result of analysed classification by TWINSPAN. Spatial distribution of the communities; 'A' community is concentrated at an altitude of about 1,300 meters in Mt. Taebaek(II region). 'B' and 'C' communities are concentrated at an altitude of between 700 and 1500 meters in Mt. Seorak and Odae(Iregion). 'D' and 'E' communities are concentrated at an altitude of below 1,100 meters in Mt. Cheongok and geumdaebong(II region), and also Mt. Seorak and Odae(Iregion). Arboral and shrub populations, maximum species diversity and height of arboral of each communities have a characteristic of decreasing according to increasing altitude gradually. And the result of studying on arboreal growth increment with up to 40-year-old trees, there is no special tendency with growth increment in the altitude of subnormal 1,100 meters, but there is a tendency that growth increment becomes lower in the altitude of more than 1,100 meters. In correlation analysis, it is -0.53 in the Quercus mongolica and Betula costata community at an altitude of over 1,000 meters, the correlation shows negative(-). It is +0.59 in the Quercus mongolica and Rubus crataegifolius community at an altitude of less than 1,000 meters, the correlation shows positive(+). And those are cognate trees with the correlation of Betula costata, Betula costata Trautv., Tripterygium regelii Sprague&Takeda., Acer barbinerve Maxim. With a summary of the results, the changes in the environment according to the elevation affect Quercus mongolica community.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.207-219
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• 2015

The purpose of this study is to show the geographical distribution and the temporal variation of the emission amount of biogenic volatile organic compounds(BVOCs) emanated from forests at Jeju Island. The total emission amount of BVOCs calculated by using the CORINAIR Methodology is $3612ton\;yr^{-1}$ at Jeju Island. More than half of BVOCs emissions is come from coniferous forest, and 45 per cent from broad leaved forest. The others is attributed to grassland. Of total emission of BVOCs, isoprene accounts for 28 per cent, monoterpene for 32 per cent, and other VOCs for about 40 percent, respectively. It can be shown that $3000{\sim}10000kg\;yr^{-1}$ of BVOCs is emitted at the zone with dense forest from an altitude of 500 m to the top of Mt. Halla, and less than $1500kg\;yr^{-1}$ at the zone an altitude of below 500 meters. The monoterpene emission is more than $1500kg\;yr^{-1}$ due to the existence of a colony of Abies koreana at the place with more than 1500 meters and a community of Pinus thunbergii and Cryptomeria japonica at the elevation of 500~700 m. In the case of isoprene emission, there is $1500{\sim}3000kg\;yr^{-1}$ at the zone of an elevation from 700 m to 1500 m due to dense broad leaved forest and very little of its emission at an elevation of more than 1500 meters because there is hardly broad leaved trees grown. In this study, emission of BVOCs according to the altitude above sea level is estimated under the situation of lack of the data for broad leaved tree. More detailed data and information for the distribution of broad leaved trees are needed in order to calculate more realistic BVOC emission.

• Korean Journal of Environmental Biology
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• v.20 no.3
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• pp.216-223
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• 2002

This study was carried out to classify forest vegetation community of Dodeokbong and Baekwunbong in Gyeryongsan. Employing the releve method of Dierssen, 89 plots were sampled. Forest community was classified into Quercus mongolica community, Quercus serrata community, Quercus variabitis community, Pinus densiflora community, Carpinus laxiflora community, and Pinus rigida-Pinus thunbergii community. Quereus mongolica community was found in high altitude and steep area, Quercus serrata community in relatively low altitude and steep slope area, and Quercus variabilis in southern arid and low area compared with Quercus mongolica community. Pinus densiflora community is present in relatively high altitude and narrow arid ridge area. And, Carpinus laxiflora community is mainly distributed in southern valley area. Pinus rigida-Pinus thunbergii community is planted community.

• Korean Journal of Environmental Biology
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• v.24 no.4
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• pp.337-358
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• 2006

The field survey was conducted weekly from April to October in 2004 and 2005 on the sites along the 5.16 road. Sampling sites were made every 100 m height starting from 250 m altitude of both sides of Mt. Halla along 5.16 Road, which crosses the mountain from North to South. Totally 31,698 individuals of 76 species belonged to 25 families were collected. It was July that showed the largest number of species, as 48 species in the northern sloper 42 in the southern slope, and 22 at the highest site (at an altitude of 750 m), while it was April that showed the smallest as 17 species, 15 and 5, respectively. As for monthly fluctuation, the northern slope and the highest site reached their top in August, whereas it was June in the southern slope. In the analyses of similarity (chord distance) of any pair of temporal communities, the closest pair was between June and July in the northern slope area, between July and August in the southern slope and between July and September at the highest site, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.9
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• pp.1090-1097
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• 2007

The multibeam surveillance radar is a state-of art of 3D radar technology. It applies the stacked beam-on-received realized by a digital beamformer. In this paper, a design concept of beamformer and a method of target altitude extraction for multibeam surveillance radar in the normal environmental condition considering no multipath situations are proposed and investigated. The extraction algorithm based on antenna sine space coordinated system in a FFT digital beamformer is described. The proposed algorithm is simulated by 1 look-up table data and confirmed to have consistent results in accordance with a variety of target altitudes and a full radar frequency range.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1155-1167
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• 2018

We developed a small sensor observation system (SSOS) at a relatively low cost to observe the atmospheric boundary layer. The accuracy of the SSOS sensor was compared with that of the automatic weather system (AWS) and meteorological tower at the Korea Meteorological Administration (KMA). Comparisons between SSOS sensors and KMA sensors were carried out by dividing into ground and lower atmosphere. As a result of comparing the raw data of the SSOS sensor with the raw data of AWS and the observation tower by applying the root-mean-square-error to the error, the corresponding values were within the error tolerance range (KMA meteorological reference point: humidity ${\pm}5%$, atmospheric pressure ${\pm}0.5hPa$, temperature ${\pm}0.5^{\circ}C$. In the case of humidity, even if the altitude changed, it tends to be underestimated. In the case of temperature, when the altitude rose to 40 m above the ground, the value changed from underestimation to overestimation. However, it can be confirmed that the errors are within the KMA's permissible range after correction.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.403-406
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• 2009

This research is based on the altitude temperature, pressure and humidity, as defined by MIL-HDBK-310 standard and modifies this conditions to conform to the new standard MIL-STD-810F and test procedure given in AIAA-2466 from this fundamental guideline optimal design and sizing of test section, inlet, exhauster duct, temperature and humidity control was performed.

• Korean Journal of Remote Sensing
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• v.33 no.1
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• pp.15-24
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• 2017

Jellyfish (cnidarian) are conspicuous in many marine ecosystems when in bloom. Despite their importance for the ecosystem structure and function, very few sampling programs are dedicated to sample jellyfish because they are patchily distributed and easily clogged plankton net. Although satellite remote sensing is an excellent observing tool for many phenomena in the ocean, their uses for monitoring jellyfish are not possible due to the coarse spatial resolutions. Hence, we developed the low altitude remote sensing platform to detect jellyfish in high resolutions, which allow us to monitor not only horizontal, but also vertical migration of them. Using low altitude remote sensing platform,we measured the jellyfish from the pier at the Chesapeake Biological Laboratory in Chesapeake Bay. The patterns observed included discrete patches, in rows that were aligned with waves that propagated from deeper regions, and aggregation around physical objects. The corresponding areas of exposed jellyfish on the sea surface were $0.1{\times}10^4pixel^2$, $0.3{\times}10^4pixel^2$, and $2.75{\times}10^4pixel^2$, respectively. Thus, the research result suggested that the migration of the jellyfish was related to the physical forcing in the sea surface.