• Asian Journal of Atmospheric Environment
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• 제6권1호
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• pp.33-40
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• 2012

In this study, we characterized the physical form of allergenic Cry j 1 in the urban atmosphere. Through an immunofluorescence antibody method, we showed that allergenic Cry j 1 exists as fine particles (${\leq}1.1{\mu}m$). To determine Cry j 1 concentrations and its particle size distribution, we used the ELISA method to confirm that most Cry j 1 exists as fine particles in the urban atmosphere and is found at high concentrations on fine day next to rainy day. Furthermore, we evaluated Cry j 1 denaturation by using the Biacore J system based on the surface plasmon resonence (SPR) principle and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). We showed that the dissociation constant ($K_D$) of Cry j 1 that has been exposed to urban polluted air is lower ($1.76{\times}10^{-14}$ M) than that of Cry j 1 ($1.32{\times}10^{-9}-3.37{\times}10^{-9}$ M) of original pollen grains that has not been exposed to air pollutants. Cry j 1 turns into low molecular weight proteins by reacting with various acidic solutions. In sum, we showed that allergenic Cry j 1 exists as fine particles that can deposit in the lower respiratory tract. This finding clarifies the relationship between Japanese cedar pollinosis and air pollutants.

• Clinical and Experimental Pediatrics
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• 제55권9호
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• pp.322-329
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• 2012

Purpose: Aeroallergens are important causative factors of allergic diseases. Previous studies on aeroallergen sensitization rates investigated patients groups that had visited pediatric allergy clinics. In contrast, we investigated sensitization rates in a general population group of elementary school to teenage students in Incheon, Jeju, and Ulsan. Methods: After obtaining parental consent, skin-prick tests were performed on 5,094 students between March and June 2010. Elementary school students were tested for 18 common aeroallergens, whereas middle and high school students were tested for 25 allergens. The 25 allergens included Dermatophagoides pteronyssinus, Dermatophagoides farinae, pollen (birch, alder, oak, Japanese cedar, pine, willow, elm, maple, Bermuda grass, timothy grass, rye grass, orchard grass, meadow grass, vernal grass, mugwort, Japanese hop, fat hen, ragweed, and plantain), and mold (Penicillatum, Aspergillus, Cladosporium, and Alternaria). Results: The sensitization rates in descending order were 25.79% (D. pteronyssinus ), 18.66% (D. farinae ), 6.20% (mugwort), and 4.07% (willow) in Incheon; 33.35% (D. pteronyssinus ), 24.78% (D. farinae), 15.36% (Japanese cedar), and 7.33% (Alternaria) in Jeju; and 32.79% (D. pteronyssinus), 30.27% (D. farinae), 10.13% (alder), and 8.68% (birch) in Ulsan. The dust mite allergen showed the highest sensitization rate among the 3 regions. The sensitization rate of tree pollen was the highest in Ulsan, whereas that of Alternaria was the highest in Jeju. The ragweed sensitization rates were 0.99% in Incheon, 1.07% in Jeju, and 0.81% in Ulsan. Conclusion: The differences in sensitization rates were because of different regional environmental conditions and distinct surrounding biological species. Hence, subsequent nationwide studies are required.

• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.753-761
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• 2017

The heartwood (HW) of Japanese cedar (Cryptomeria japonica) has usually a reddish color. But some trees have black-colored heartwood (BHW). BHW of Japanese cedar has a low commercial value because of the appearance. Therefore, in this study, a comparative analysis was conducted to evaluate the differences in the physical, mechanical, and inorganic element properties, and decay resistance of red-colored heartwood tree (RHW) and BHW. The physical properties showed significant difference between sapwood (SW) and HW, but there was no significant difference between RHW and BHW. From the results of mechanical properties, no significant difference was recognized in SW of RHW, HW of RHW, SW of BHW, and HW of BHW. There were decay resistance differences between RHW and BHW in HW, and between HW and SW in both RHW and BHW, respectively. The magnesium (Mg), potassium (K), and calcium (Ca) contents had significant differences between SW and HW in both RHW and BHW. In this present study, the decay resistances and the contents of Mg and K were higher in HW than in SW both for RHW and BHW, while these measurements were lower in RHW than in BHW. Therefore, BHW was considered to be worthy as a high-quality material as RHW.

• Journal of the Korean Wood Science and Technology
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• 제48권3호
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• pp.345-363
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• 2020

본 연구는 배할 및 인사이징 전처리가 횡단면 크기 150 mm 이하 삼나무와 낙엽송 수심재의 고온건조 특성에 미치는 영향을 확인하기 위해 수행되었다. 그 결과, 전처리는 표면할렬과 수축률에 대하여 유의한 차이를 나타내었다. 배할처리는 표면할렬 발생을 줄이기 위한 전처리로서 적합하였으나, 인사이징은 재면의 자상이 서로 연결됨으로써 표면할렬로 전환되는 현상을 야기하기 때문에 전처리로서 적합하지 않았다. 수축률은 전처리 조건에 따라 건조 후 최종함수율이 인사이징, 배할, 배할-인사이징 순으로 감소되는 경향을 나타냄으로써 유의한 결과를 나타내었다. 뒤틀림은 미성숙재의 수축이방성보다 목리각도가 더 크게 영향을 주었으며, 전처리의 영향은 없었다.

• Journal of Forest and Environmental Science
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• 제30권3호
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• pp.285-292
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• 2014

Essential oil yields and chemical compositions from 5 populations of Chamaecyparis obtusa with several environmental factors were investigated through essential oil extracted distillation apparatus and metabolite profiling by GC-MS analysis. Among the populations, content of essential oil at Gokseong was significantly higher than other populations. To compare the several environmental factors affecting on chemical composition and essential oil yields from C. obtuse at Gokseong, the environmental factors (soil condition, temperature, humidity, and moisture content) were measured during 1 year. The essential oils at Goksung based on humidity on March, July, and November was significantly different from other months. The essential oils at Goksung based on temperature on July and August was significantly different from other months. The essential oils at Goksung based on the moisture content on September were significantly different from other months. The percentage of T-N, OM, and yield of oil at Gokseong were significantly different on from other populations. The main constituents of C. obtusa at all populations were ${\alpha}$-pinene, ${\beta}$-pinene, ${\alpha}$-terpinene, ${\gamma}$-terpinene, terpinene-4-ol, isobonyl acetate, terpinyl acetate, and cedar acetate. Specially, Essential oil compositions (%) of ${\alpha}$-terpinene and cedar acetate were higher at Gokseong than at other populations. The chemical compositions of essential oils were variable depend on populations and environmental conditions. Therefore, this study might be used as fundamental research on study for selection of high productive terpenoids and for understanding about biosynthesis of essential oils in C. obtusa.

• 한국산림과학회지
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• 제84권3호
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• pp.394-405
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• 1995

온대 삼림지대에서 산화 적지나 개벌 적지에 왕성하게 번성하는 것이 ericaceous속이다. ericaceous속의 식물들은 성장이 빨라서 다른 종과의 경쟁에서 유리하고 또한 allelopathy 효과 때문에 침엽수 갱신에 영향을 미친다. Kalmia가 번성하는 지역에서는 삼림 갱신이 잘 되지 않거나 조림한 침엽수의 생장이 저조하였다. 이러한 생상 저해 현상은 서유럽의 Calluna - Sitca spruce - Scots pine 생태계와 미국의 북서 태평양 지역의 Gaultheria - cedar/hemlock 생태계에서도 나타나고 있다. 삼림이 파괴된 다음에 Kalmia - black spruce 생태계의 다양한 변화는 침엽수 생장을 저해하거나 갱신을 방해하는 원인으로 생각되어지고 있다. 양분경쟁에 대한 논쟁의 여지는 있으나 Kalmia는 black spruce 생장을 억제하는 주원인으로 작용한다. 여러 곳의 야외, 실내 및 온실에서 한 실험 결과는 이러한 결론을 뒷받침해 주고 있다. 본 논문에서는 Kalmia 잎으로부터 8가지의 폐놀물질을 분리동정해 냈으며 이들 중 4가지는 black spruce에 고도의 독성을 나타냈다. Kalmia 우점지역에서 allelopathic 영향을 적게 하므로써 black spruce의 갱신을 증진시키기 위한 여러 가지 방법에 대한 고찰을 하였다.

• Journal of the Korean Wood Science and Technology
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• 제28권1호
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• pp.36-41
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• 2000

목재는 2-메타크릴로일옥시에틸 이소시아네이트(MOI)와 $50-60^{\circ}C$에서 촉매존재하에서 매우 쉽게 반응하였다. 적외선 분광분석을 통하여, 목재가 MOI와 우레탄결합($1715cm^{-1}$)를 형성하고 있을 뿐만 아니라, 올레핀구조의 탄소간 이중결합 ($1635cm^{-1}$)이 존재하고 있음이 밝혀졌다. 도입된 메타크릴산기는 다른 비닐모노머와의 그래프트공중합시 반응시점으로 작용할 것이다. 또한 MOI처리목재는, MOI와의 반응에 의해 친수성이던 목재의 표면이 소수화되어 접촉각이 증대되는 결과를 낳았다. X선광전자분광분석(XPS)의 결과, 목재의 표면부위의 대부분은 MOI에 의해 개질되었음을 밝혀졌다.

• 한국전자파학회논문지
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• 제18권1호
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• pp.96-104
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• 2007

현재 국제적으로 수풀 손실 예측 모델이나 측정 데이터가 매우 부족하다. 본 논문에서는 2005년과 2006년, 2년에 걸쳐 $1{\sim}6\;GHz$ 대역 국내 수풀 및 가로 환경에 많이 분포하는 소나무(pine tree), 히말라야시다(hymalaya cedar),플라타너스나무(plane tree), 메타나무(dawn-redwood tree)등의 수풀에 대한 수풀 손실 특성 측정 수행 결과로부터, ITU-R P.833에서 제시하고 있는 RET(radiative energy transfer) 모델 파라미터를 도출하였으며, 모델 보정을 시도하였다. 본 연구 결과는 2005년, 2006년 ITU-R SG WP 3J 회의에서 권고서에 반영되었다.

• Journal of the Korean Wood Science and Technology
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• 제45권2호
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• pp.202-212
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• 2017

This study was to establish the interrelation between chemical compositions and near infrared (NIR) spectra for the classification on distinguishability of domestic gymnosperms. Traditional wet chemistry methods and infrared spectral analyses were performed. In chemical compositions of five softwood species including larch (Larix kaempferi), red pine (Pinus densiflora), Korean pine (Pinus koraiensis), cypress (Chamaecyparis obtusa), and cedar (Cryptomeria japonica), their extractives and lignin contents provided the major information for distinction between the wood species. However, depending on the production region and purchasing time of woods, chemical compositions were different even though in same species. Especially, red pine harvested from Naju showed the highest extractive content about 16.3%, whereas that from Donghae showed about 5.0%. These results were expected due to different environmental conditions such as sunshine amount, nutrients and moisture contents, and these phenomena were also observed in other species. As a result of the principal component analysis (PCA) using NIR between five species (total 19 samples), the samples were divided into three groups in the score plot based on principal component (PC) 1 and principal component (PC) 2; group 1) red pine and Korean pine, group 2) larch, and group 3) cypress and cedar. Based on the chemical composition results, it was concluded that extractive content was highly relevant to wood classification by NIR analysis.

• 전자공학회논문지B
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• 제33B권4호
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• pp.209-216
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• 1996

In this paper, we propose a learning method of multi-layer perceptrons (MLPs) with 8-bit data precision. The suggested method uses the cross-entropy cost function to remove the slope term of error signal in output layer. To decrease the possibility of overflows, we use 16-bit weighted sum results into the 8-bit data with appropriate range. In the forwared propagation, the range for bit-conversion is determined using the saturation property of sigmoid function. In the backwared propagation, the range for bit-conversion is derived using the probability density function of back-propagated signal. In a simulation study to classify hadwritten digits in the CEDAR database, our method shows similar generalization performance to the error back-propagation learning with 16-bit precision.