• Journal of the Korean Wood Science and Technology
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• v.41 no.6
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• pp.475-489
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• 2013

This work was conducted to investigate the effect of the addition of binders, such as rapeseed flour, coffee waste, bark, pine cone and lignin powder, on the fuel characteristics of the pellets fabricated with larch and tulip tree sawdust. Moisture content, bulk density and higher heating value of most pellets fabricated with the binders exceeded the 1st-grade pellet standard designated by Korea Forest Research Institute, but ash content of the pellets fabricated with rapeseed flour or bark of 10 wt% on the dry weight basis of sawdust was satisfied with just the 2nd- or 3rd-grade standard. The durability of tulip tree-pellets was positively influenced by the addition of rapeseed flour, coffee waste or lignin powder and increased with increasing the amount of the binders. For larch-pellets, the increase of binders did not greatly affect the durability, and even the durability reduced with the increase of bark or pine cone. From the microscopic observation, the obvious feature of pellet surfaces was not identified by the type of binder but by the addition amount of the binder. In summary, the addition of binders contributed to the fuel characteristics of wood pellets, and particularly the characteristics of wood pellets fabricated with coffee waste improved greatly. Therefore, if the binders are secured sufficiently with a reasonable cost, it might be possible to commercialize wood/binder pellets, which have better fuel characteristics than conventional wood pellets.

• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.152-157
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• 2009

To obtain pure lines for breeding $F_1$ varieties of Primula malacoides, 10 lines that were considered uniform in growth and flowering characteristics were selected from self-crossings of the sixth generation ($S_6$). Plant height of the selected lines ranged from 20.8 to 33.2 cm, and number of leaves ranged from 33.6 to 54.2. The selected lines flowered at 181.4 to 207.8 days after sowing. Three lines, including 'PR-03-81', flowered in less than 190 days from sowing, while six lines, including 'PR-03-228', only flowered after more than 200 days from sowing. In terms of petal color, six lines, including 'PR-03-81', were pink, three, including 'PR-03-236', were purple, and line 'PR-03-275' was white. Flower diameter ranged from 2.4 to 2.9 cm, and number of pedicels per plant was between 15.4 and 26.4. Number of flowers per pedicel ranged from 20.2 to 30.2. Germination was more than 70%, and number of seeds per capsule (pod) ranged from 110.0 to 162.8. In summary, plant height was low and flower diameter was small and plants had many flowers and readily formed seeds. The selected lines are not only valuable as ornamental plants but could also be used as breeding materials for $F_1$ hybrids of Primula polyantha.

• Korean Journal of Remote Sensing
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• v.23 no.4
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• pp.257-272
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• 2007

This paper analyzed relationships between various features from SAR data with multiple acquisition dates and mode (frequency, polarization and incidence angles), and land-cover classes. Two typical types of features were extracted by considering acquisition conditions of currently available SAR data. First, coherence, temporal variability and principal component transform-based features were extracted from multi-temporal and single mode SAR data. C-band ERS-1/2, ENVISAT ASAR and Radarsat-1, and L-band JERS-1 SAR data were used for those features and different characteristics of different SAR sensor data were discussed in terms of land-cover discrimination capability. Overall, tandem coherence showed the best discrimination capability among various features. Long-term coherence from C-band SAR data provided a useful information on the discrimination of urban areas from other classes. Paddy fields showed the highest temporal variability values in all SAR sensor data. Features from principal component transform contained particular information relevant to specific land-cover class. As features for multiple mode SAR data acquired at similar dates, polarization ratio and multi-channel variability were also considered. VH/VV polarization ratio was a useful feature for the discrimination of forest and dry fields in which the distributions of coherence and temporal variability were significantly overlapped. It would be expected that the case study results could be useful information on improvement of classification accuracy in land-cover classification with SAR data, provided that the main findings of this paper would be confirmed by extensive case studies based on multi-temporal SAR data with various modes and ground-based SAR experiments.

• Korean Journal of Remote Sensing
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• v.15 no.1
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• pp.9-20
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• 1999

The use of climatic information is essential in the industial society. More specialized weather servies are required to perform better industrial acivities including agriculture. Especially, crop models require daily weather data of crop growing area or cropping zones, where routine weather observations are rare. Estimates of the spatial distribution of daily climates might complement the low density of standard weather observation stations. This study was conducted to estimate the spatial distribution of daily minimum and maximum temperatures in Korean Peninsula. A topoclimatological technique was first applied to produce reasonable estimates of monthly climatic normals based on 1km $\times$ 1km grid cell over study area. Harmonic analysis method was then adopted to convert the monthly climatic normals into daily climatic normals. The daily temperatures for each grid cell were derived from a spatial interpolation procedure based on inverse-distance weighting of the observed deviation from the climatic normals at the nearest 4 standard weather stations. Data collected from more than 300 automatic weather systems were then used to validate the final estimates on several dates in 1997. Final step to confirm accuracy of the estimated temperature fields was comparing the distribution pattern with the brightness temperature fields derived from NOAA/AVHRR. Results show that differences between the estimated and the observed temperatures at 20 randomly selected automatic weather systems(AWS) range from -3.$0^{\circ}C$ to + 2.5$^{\circ}C$ in daily maximum, and from -1.8$^{\circ}C$ to + 2.2$^{\circ}C$ in daily minimum temperature. The estimation errors, RMSE, calculated from the data collected at about 300 AWS range from $1.5^{\circ}C$ to 2.5$^{\circ}C$ for daily maximum/minimum temperatures.

• Korean Journal of Remote Sensing
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• v.23 no.6
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• pp.537-546
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• 2007

In hyperspectral remote sensing, linear spectral mixture model is a common procedure decomposing into the components of a mixed pixel and estimating the fraction of each end-member. Although linear spectral mixture model is frequently used in geology and mineral mapping because this model is simple and easy to apply, this model is not always valid in forest and urban area having rather complex structure. This study aims to analyze possible error for applying linear spectral mixture model. For the study, we measured laboratory spectra of mixture sample, having various materials, fractions, distributions. The accuracy of linear mixture model is low with the mixture sample having similar fraction because the multi-scattering between components is maximum. Additionally, this multi-scattering is related to the types, fraction, and distribution of components. Further analysis is necessary to quantify errors from linear spectral mixture model.

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.65-76
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• 2004

This study aims to estimate daily maximum air temperature estimated using satellite-derived surface temperature and Elevation Derivative Database (EDD). The analysis is focused on the establishment of a semi-empirical estimation technique of daily maximum air temperature through the multiple regression analysis. This tests the contribution of EDD in the air temperature estimation when it is added into regression model as an independent variable. The better correlation is shown with the EDD data as compared with the correlation without this data set. In order to provide a progressive estimation technique, we propose and compare three approaches: 1) seasonal estimation non-considering landcover, 2) seasonal estimation considering landcover, and 3) estimation according to landcover type and non-considering season. The last method shows the best fit with the root-mean-square error between 0.56$^{\circ}C$ and 3.14$^{\circ}C$. A cross-validation procedure is performed for third method to valid the estimated values for two major landcover types (cropland and forest). For both landcover types, the validation results show reasonable agreement with estimation results. Therefore it is considered that the estimation technique proposed may be applicable to most parts of South Korea.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.04a
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• pp.22-22
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• 1999

교란에 대한 고체 추진제의 연소율의 반등에 대한 이해는 고성능 추진제를 설계하는데 매우 중요한 요소이다. 그 동안의 연구는 고체 추진제의 표면에서 발생하는 교란이 매우 작은 크기로 발생한다는 선형적인 가정을 사용하여 이론적인 응답 함수를 구하였다. 특히 실험실에서 행해지는 교란에 대한 추진제의 응답 함수를 구하기 위하여 이용한 비집촉식 교란 방법을 사용하였다. 이 경우 추진제 표면으로 전달되는 복사열 전달의 크기는 레이저에 의한 복사 일전달과 기체 영의 화염에 의한 열전달을 동시에 고려하여야 한다. 그러나 언급하였던 것처럼 대부분의 이론적 연구는 추진제 표면의 온도 구매가 단열인 것으로 가정하여 진행하였다. 이러한 가정을 기체 영역으로부터 추진제로 전달되는 열전달 량이 작은 점소화초기 등에서 타당한 가정이나, 기체 영역에서 연소가 활발하게 진행되는 경우에는 비합리적인 가정이다. 본 연구에서는. 추진제의 응축 영역에서 분포 화학 반응이 발생하여, 기체 영역에서 화학반응에 의한 연소가 진행되는 경우, 복사 열전달의 교란에 대한 추진제의 응답함수를 수치적으로 계산하였다. 이때 기체 영역에서 발생하는 연소 반응은 De Luca 등에 의하여 제안된 실험적 모델인 $\alpha$ $\beta$ ${\gamma}$ 화염 모델을 사용하였으며, 추진제 표면에서의 열전달 균형에 의한 경계 조건을 사용하였다. 그러나 외부로부터 입사되는 복사광 레이저와 기체 영역의 상호 간섭은 고려하지 않았다. 수치 계산에 의한 응답 함수의 특징은 단열 조건이 사용된 이론적 응답 함수에 비하여 낮은 값을 나타내었으며, 최대치를 보이는 주파수 영역도 이론 함수에 비하여 다른 값을 보여주고 있다.연구 분석 결과 기술적 문제점으로는 배기 가스온도가 낮은데 따른 출구 부분의 Bearing, Sealing이 문제가 될 수 있다고 판단되며 배기 가스 자체에 대기 공기중에 함유되어 있던 습기가 얼어붙는(Icing화) 문제가 발생하기 때문에 배기가스의 Icing을 방지하기 위하여 압축기 끝단에서 공기를 추출하여 배기부분에 송출할 필요성이 있는 것으로 판단되었다. 출구가스의 기체 유동속도가 매우 빠르므로 (100-l10m.sec) 이를 완화하기 위한 디퓨저의 설계가 요구된다고 판단된다. 또 연소기 후방에 물을 주입하는 경우 열교환기 및 기타 부분품에 발생할 수 있는 부식 및 열교환 효율 저하도 간과할 수 없는 문제로 파악되었다. 이러한 기술적 문제가 적절히 해결되는 경우 비활성 가스 제너레이터는 민수용으로는 대형 빌딩, 산림, 유조선 등의 화재에 매우 적절히 사용되어 질 수 있을 뿐 아니라 군사적으로도 군사작전 중 및 공군 기지의 화재 그리고 지하벙커에 설치되어 있는 고급 첨단 군사 장비 등의 화재 뿐 아니라 대간첩작전 등에 효과적으로 활용될 수 있을 것으로 판단된다.가 작으며, 본 연소관에 충전된 RDX/AP계 추진제의 경우 추진제의 습기투과에 의한 추진제 물성 변화는 미미한 것으로 나타났다.의 향상으로, 음성개선에 효과적이라고 사료되었으며, 이 방법이 편측 성대마비 환자의 효과적인 음성개선의 치료방법의 하나로 응용될 수 있으리라 생각된다..7%), 혈액투석, 식도부분절제술 및 위루술·위회장문합술을 시행한 경우가 각 1례(2.9%)씩이었다. 13) 심각한 합병증은 9례(26.5%)에서 보였는데 그중 식도협착증이 6례(17.6%), 급성신부전증 1례(2.9%), 종격동기흉과 폐염이 병발한 경우와 폐염이 각 1례(2.9%)였다. 14

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.121-125
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• 2005

Most of the cells, specially in the skin, free radicals and reactive oxygen species induced aging, accompanying with diseases. The pinaceae family is very familiar plant with Korean spirit. However, those plants were not estimated for natural products in manufactural process. We employed 4 different plants, Pinus koraienis S et Z. Pinus banksiana LAMBERT. Pinus rigida MILL. Pinus densiflora S. et Z. in pinceae family. The ethanol extracts were prepared for three different parts of plant, wood, bark and leaf, respectively. In this study, we carried out free radical and superoxide radical scavenging assay to investigate the anti-oxidative activity The bark and leaf part of plants showed similar anti-oxidant effect. L-ascorbic acid and $\alpha$-tocopherol at $10{\mu}g/mL$. Also we tried to investigate inhibitory effects of elastase activity in in vitro experiments on pinaceae plant extract as a matters for functional cosmetics. Among those plants, the bark of Pinus rigida MILL. and Pinus densiflora S. et Z. showed inhibitory effect. The cell viability was evaluated with MTT assay. The potential relationship was shown between the cell viability and anti-oxidant effect because the anti-oxidant effects were positively correlated wvith the cell growth in MTT assay. As the results in our experiments, we expect the potential activities of pinaceae as a material of functional cosmetics.

• Journal of Life Science
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• v.31 no.4
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• pp.377-384
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• 2021

Researching the soil fungal community is important to understand the interaction between fungi and living plants. However, too few studies have examined the soil fungal community and their interactions with plants. Rhododendron mucronulatum, commonly known as Korean rosebay, is an important forest resource that has aesthetic, ecological, and potential pharmacological values. We used a pyrosequencing method to analyze the characteristics of fungal communities from R. mucronulatum soil samples from Biseul mountain county park, which is one of the famous places for large R. mucronulatum colonies in South Korea. We collected soil core samples in February and August at three sites in the Biseul Mountain County Park, taking into consideration the regional and seasonal conditions. We obtained 454,157 validated reads after pyrosequencing all six samples. The fungal communities from the first observation spot in August had the richest species diversity among the samples. Basidiomycota, Ascomycota, and Mortierellomycota were major phyla in the samples. Agaricales_f, Mortierellaceae, and Clavariaceae were major families in the samples. The genus Mortierella was the most dominant in all six samples. Overall, 19 genera could be associated with R. mucronulatum. Sample 1 had 109 genera in sample 1, sample 2 had 111 genera, and sample 3 had 112 genera that were uniquely identified. The samples collected in August had 28 identified genera, that existed only in summer samples, indicating a weather effect. This study can be used as basic research to understand the relationship between soil fungi and plants.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.363-373
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• 2021

An ecological niche is defined as the specific role of a species influenced by time, space, and other resources. By investigating overlaps between ecological niches of different species, we could estimate the degrees of interspecific competition. Such studies often use geographic information systems (GIS) to discover niche overlaps between species. In this study, we used GIS to estimate the spatial niches of two Korean frog species(Pelophylax nigromaculatus and P. chosenicus). This enabled us to predict their geographic distributions in order to identify their coexistence regions and distribution patterns. The results confirmed that altitude was an important variable for predicting their distribution, with a correlation with their climatic range. Spatial distributions of the two frog species were highly overlapped, as the distribution range for P. nigromaculatus included most of the range of P. chosenicus, showing a sympatric distribution pattern. Within the coexisting regions, however, the presence sites for the two species did not overlap, implying weak competition. To confirm the principal factors influencing their competitive relationship and reasons for their sympatric distribution pattern, we need more detailed in-depth studies on the diverse environmental variables within the regions where the two species coexist. By doing so, we would be able to identify various mechanisms for avoiding competition in sympatric frog species.