• 한국산림과학회지
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• 제87권4호
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• pp.631-641
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• 1998

이 연구의 목적은 강원도 평창군 중왕산 지역에 자라는 활엽수림중 신갈나무림을 대상으로 임분형을 구분하고 이에 따른 신갈나무의 형질을 비교 분석하며, 육림작업시 적용될 수 있는 적절한 미래목 본수 및 미래목들간의 간격을 결정하는 것이다. 연구대상지에 0.05ha 크기의 시험구 22개에 대한 자료조사를 통해 재적혼효율에 따른 임분형을 분류한 결과 중왕산 지역의 신갈나무림은 4개의 임분형(신갈나무 단순림, 신갈나무 - 기타활엽수림, 신갈나무 - 소나무림, 기타활엽수 - 신갈나무림)으로 구분되었다. 이중 신갈나무의 혼효율이 25% 이하인 기타활엽수 - 신갈나무림 임분형에서 신갈나무의 수간형질이 가장 우수하게 나타났으며, 신갈나무 단순림이나 신갈나무 - 소나무 혼효림 보다 신갈나무 - 기타활엽수 혼효림에서 신갈나무의 수간형질이 더 좋았다. 그러므로 신갈나무림에 대한 경영목표를 고품질의 목재생산에 둔다면 기타 활엽수와 적절한 혼효를 유지시키는 방향으로 신갈나무의 육림방향을 설정하는 것이 바람직하다고 판단된다. 신갈나무단순림에서의 미래목 본수는 122본/ha이며, 미래목간 간격은 9.15m가 적절한 것으로 나타났다. 그리고 임분형별 적절한 미래목 간격은 II형과 IV형 임분에서는 7.2m - 9.3m 정도가, III형 임분에서는 8.0m가 적절하며, 신갈나무가 혼효되지 않은 V형 임분에 대하여는 미래목 간격이 7.1m - 9.5m가 적절할 것으로 나타났다.

• 펄프종이기술
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• 제46권4호
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• pp.21-27
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• 2014

As a part of the study on manufacture of low density paper by organic bulky agent treatment, the effects of cationic fatty acid bulky agent on physical and optical properties of handsheets were elucidated. The research on change of physical and optical properties of paper samples according to bulky agent concentration, pulp type, and pulp combination were carried out. The results demonstrated that an increase of the concentration of cationic fatty acid bulky agent was proportional to an increase of the bulky properties of paper samples while tensile strength decreased. Also, the more the treated concentration of cationic fatty acid bulky agent increased, the more the ISO brightness of paper samples decreased while the opacity increased. The effectiveness of bulky agent with softwood bleached kraft pulp (SwBKP) was higher than that with hardwood bleached kraft pulp (HwBKP). In addition, the effectiveness with mixed pulps was higher than that with single pulp.

• 펄프종이기술
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• 제45권1호
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• pp.42-51
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• 2013

In this study, oil palm biomass such as empty fruit bunch (EFB) and palm kernel shell (PKS) was used as raw materials for making pellets. Hardwood sawdusts were also mixed with EFB and PKS for making pellets. For improving a bad forming behavior in a pelletizer, 1 to 3 per cent of corn starch based on oven-dried weight biomass was added. The starch contributed to the decrease of dust generation in addition to the improvement of forming capability during pellet forming. Heating values of every pellets made of EFB and PKS were higher than 4,300 kcal/kg for the first grade pellet, irrespective of addition of sawdusts. However, the pellets made of EFB and PKS had ash contents over 3 per cent, which made it impossible to be applied for home use. Instead, they could be applied for industrial use. For studying their combustion characteristics, the pellets from the mixtures of EFB, PKS and sawdusts were analyzed using thermal gravimetric analyzer (TGA). From the TGA results, thermal decomposition of EFB and PKS occurred following three including endothermic reaction and dehydration, devolatilization of the major chemical components, and finally combustion of residual lignin and char.

• 한국환경복원기술학회지
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• 제18권2호
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• pp.89-104
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• 2015

In order to effectively manage forested areas in South Korea on a national scale, using remotely sensed data is considered most suitable. In this study, utilizing Land coverage maps and Forest type maps of national geographic information instead of collecting field data was tested for conducting supervised classification on SPOT-5 and KOMPSAT-2 imagery focusing on forested areas. Supervised classification were conducted in two ways: analysing a whole area around the study site and/or only forested areas around the study site, using Support Vector Machine. The overall accuracy for the classification on the whole area ranged from 54.9% to 68.9% with kappa coefficients of over 0.4, which meant the supervised classification was in general considered moderate because of sub-classifying forested areas into three categories (i.e. hardwood, conifer, mixed forests). Compared to this, the overall accuracy for forested areas were better for sub-classification of forested areas probably due to less distraction in the classification. To further improve the overall accuracy, it is needed to gain individual imagery rather than mosaic imagery to use more spetral bands and select more suitable conditions such as seasonal timing. It is also necessary to obtain precise and accurate training data for sub-classifying forested areas. This new approach can be considered as a basis of developing an excellent analysis manner for understanding and managing forest landscape.

• 펄프종이기술
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• 제37권2호
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• pp.78-86
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• 2005

Hwaseonji(Korean traditional paper) used for writing and painting has been made from the mulberry bast-fiber and the short-length fiber pulps, wood pulps. However, besides wood pulps, other short-length fiber pulps also can be used instead of wood pulps. Hence, this research was carried out to make the various Hwaseonjis with the different properties, using the five kinds of short-length fiber pulps respectively. The short-length fiber pulps used in this research were softwood bleached kraft pulp(SwBKP) hardwood bleached kraft pulp(HwBKP), rice-straw bleached sulfite pulp(RsBSP), bamboo bleached kraft pulp(BbBKP) and recycled pulp from vellem paper(RP). And, the mixture ratios of the mulberry bast-fiber pulp and short-length fiber pulps were 100:0, 80:20, 60:40, 40:60 and 20:80. After various Hwaseonjis were made from different mixtures mentioned above with hand-made method, physical properties and chinese ink blot property of each paper were measured. The strengthes were the highest in the Hwaseonji made from the mixture of the mulberry bast-fiber pulp and SwBKP. However, chinese ink blot property and smoothness were better when RsBSP, BbBKP or RP were mixed into the mulberry bast-fiber pulp. As a result, the various kinds of Hwaseonjis which the users can choose based on their needs were made.

• Journal of Ecology and Environment
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• 제43권4호
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• pp.364-375
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• 2019

Background: Ecologists continue to investigate the factors that potentially affect the pattern and magnitude of tree damage during catastrophic windstorms in forests. However, there still is a paucity of research on which trees are more vulnerable to direct damage by winds rather than being knocked down by the fall of another tree. We evaluated this question in a mixed hardwood-softwood forest within the Big Thicket National Preserve (BTNP) of southeast Texas, USA, which was substantially impacted by Hurricane Rita in September 2005. Results: We showed that multiple factors, including tree height, shade-tolerance, height-to-diameter ratio, and neighborhood density (i.e., pre-Rita stem distribution) significantly explained the susceptibility of trees to direct storm damage. We also found that no single factor had pervasive importance over the others and, instead, that all factors were tightly intertwined in a complex way, such that they often complemented each other, and that they contributed simultaneously to the overall susceptibility to and patterns of windstorm damage in the BTNP. Conclusions: Directly damaged trees greatly influence the forest by causing secondary damage to other trees. We propose that directly and indirectly damaged (or susceptible) trees should be considered separately when assessing or predicting the impact of windstorms on a forest ecosystem; to better predict the pathways of community structure reorganization and guide forest management and conservation practices. Forest managers are recommended to adopt a holistic view that considers and combines various components of the forest ecosystem when establishing strategies for mitigating the impact of catastrophic winds.

• 한국환경복원기술학회지
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• 제17권1호
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• pp.65-79
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• 2014

This study selected Nakdong River basin zone in Daegu as an example area to conduct landscapetope classification and aesthetic value assessment of landscape according to the classified landscapetope. The main result of this research can be summed up as following. First, the result of landscapetope type classification showed 28 types of landscapetope including complex residential area (AA), natural stream type with copious vegetation (BA), forest type centered on mixed forest of soft and hardwood (EB) along with 129 types of imputed specific landscapetope. The result of the total first assessment using B-VAT showed the first grade 10 types, II grade 4 types, III grade6 types, IV grade 3 types, 5 types for V grade with the lowest value. The second assessment conducted toward the landscapetope types with the grade higher than the average (including III grade) in the result of the first assessment showed that there are 66 spaces for the sites (1a, 1b) with special meaning for aesthetic landscape evaluation. And also, there were 69 spaces for those (2a, 2b, 2c) with meaning for aesthetic landscape evaluation. The design model of this research is largely divided into improvement goal and specific execution plan. First, the improvement goal is divided into 6 categories including conservation area, complementary area, and restoration area, and the specific execution plan is divided into 14 categories including special landscape management area, general landscape management area, conservation of hill areas with optically good condition. A comprehensive master plan was suggested by directly applying the set landscape planning model to the subject place of this research.

• Journal of the Korean Wood Science and Technology
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• 제31권1호
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• pp.10-15
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• 2003

본 연구는 주요 국산 활엽수재 원반에서 채취한 원주상(圓周狀)슬라이스를 오-븐에서 급속건조하면서 각 원반내 함수율의 방사방향 분포추이를 조사하기 위하여 수행하였다. 느티나무의 경우 변재부 또는 심변재경계부가 이미 섬유포화점 이하의 함수율에 도달하였으나, 최내측슬라이스는 아직도 약 40% 정도의 높은 함수율을 나타내었다. 벚나무의 경우 최내측 슬라이스와 바로 인접한 슬라이스간의 수분경사가 건조시간이 경과하면서 더욱 심해지는 경향을 보였다. 음나무 원반에서는 생재상태에서는 심재부의 함수율이 변재부보다 약 23% 정도 더 높은 분포를 보였으며, 이러한 분포유형이 평균함수율 약 15%일 때까지도 지속되었다. 참중나무의 경우 전(全)건조기간에 걸쳐 외주측의 심변재혼합 슬라이스들과 최내측 슬라이스의 함수율이 나머지 부위의 함수율보다 낮은 값을 나타내었다.

• 한국산림과학회지
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• 제71권1호
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• pp.14-21
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• 1985

본(本) 연구(硏究)는 목재(木材) 고유(固有)의 특성(特性)인 흡습성(吸濕性) 및 수축(收縮), 팽창(膨脹)의 이방성(異方性)에 의한 목재(木材) 자체(自體) 및 목제품(木製品)의 가치(價値) 저하(低下)를 방지(防止)하고 목재(木材)의 천연적(天然的)인 아름다운 무늬를 살려 더욱 목재(木材)의 효용가치(効用價値) 높이 기 위하여 비교적(比較的) 가격(價格)이 싸고 독성(毒性)이 없을 뿐만 아니라 주입처리(注入處理)가 용역(容易)한 PEG를 이용(利用)한 목재(木材)의 치수 안정화(安定化) 기술(技術)을 개발(開發)하기 위한 일환(一環)으로 PEG 분자량별(分子量別)(200, 400, 600, 1000, 1500, 2000, 4000, 6000) 및 수종별(樹種別)(Pinus densiflora S. et Z., Larix leptolepis Gordon., Cryptomeria japonica D. Don., Cornus controversa Hemsl., Quercus variabilis Blume., Prunus sargentii Rehder.)로 치수 안정화(安定化) 효과(効果)를 조사(調査)하였던 바, 다음과 같이 요약(要約)될 수 있었다. 1) PEG 주입율(注入率)은 분자량(分子量) 400일 때 137.22%(Pinus densiflora)로 최대치(最大値)를 나타내었고 그 이후(以後)는 비교적(比較的) 완만(緩慢)하게 감소(減少)하는 경향(傾向)을 보여 주었으며 비중(比重)이 낮을수록 PEG 주입량(注入量)도 증가(增加)하는 것으로 밝혀졌다. 2) 부피 팽윤율(澎潤率)은 비중(比重)에 의한 영향(影響)을 별로 받지 않았으며 굴참나무가 분자량(分子量) 400~2,000에 이르기까지 12~18%의 범위(範圍)내에 분포(分布)한 것을 제외(除外)하고는 대부분(大部分) 분자량(分子量) 600일 때 가장 높은 값을 나타내었고, 일반적(一般的)으로 활엽수재(濶葉樹材)가 침엽수재(針葉樹材)보다 높은 부피 팽윤율(澎潤率)을 보여 주었다. 3) 부피 팽윤(澎潤) 감소율(減少率)은 수종(樹種)에 따라 약간의 예외(例外)는 있었으나 대부분이 PEG 분자량(分子量) 400에서 최대치(最大値)를 나타내었고 삼나무의 경우 95.09%로서 최대치(最大値)를 나타내었으며, 산벚나무를 제외(除外)하고는 모두 80% 이상(以上)을 나타내었지만 분자량(分子量) 1,000 이상(以上)에서는 팽윤(膨潤) 감소율(減少率)이 70% 이하(以下)로 떨어졌다. 4) 치수 안정화(安定化) 효율(效率)은 비중(比重)이 큰 활엽수재(濶葉樹材)가 침엽수재(針葉樹材)보다 월등하게 높았으며 전건비중(全乾比重)이 0.89인 굴참나무는 전(全) 분자량(分子量) 범위(範圍)에 걸쳐 부피 팽윤감소율(澎潤減少率)이 1.6 이상(以上)이었는데, 일반적(一般的)으로 분자량(分子量)이 작을수록 우수(優秀)하였으나 분자량(分子量) 4,000 이상(以上)에서는 별로 차이(差異)를 나타내지 않았다. 5) 이상(以上)과 같은 결과(結果)를 종합(綜合) 분석(分析)한 바 PEG 처리(處理)에 의한 치수 안정화(安定化)는 활엽수재(濶葉樹材)의 경우, 특(特)히 효율적(效率的)이며 비록 팽윤감소율(澎潤減少率)이 분자량(分子量) 400에서 가장 높은 수치(數値)를 나타내었지만 PEG 주입율(注入率), 부피 팽윤율(澎潤率), 팽윤감소율(澎潤減少率) 및 치수 안정화(安定化) 효율(效率)을 감안할 때 분자량(分子量) 200~1,500 사이의 것을 적절(適切)한 비(比)로 혼합(混合) 사용(使用)하는 것이 바람직한 것으로 사료(思料)되며, 실용화(實用化)를 위해서는 각 분자량(分子量)의 PEG 혼합비율(混合比率)에 따른 부피 팽윤율(澎潤率), 팽윤감소율(澎潤減少率) 및 치수 안정화(安定化) 효율(效率)에 대한 보다 집중적(集中的)인 연구(硏究)가 요구(要求)된다.

• 한국환경복원기술학회지
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• 제4권4호
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• pp.1-11
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• 2001

This study was carried out to analyze the characteristics of forest environmental and stream morphological factors by using the quantification theory(I) for evaluation of the watershed stability. Present annual mean sediment yield of erosion control dams were investigated in 167 sites of erosion control dam constructed during 1986 to 1999 in Gyeongbuk. The results obtained from this study were summarized as follows; According to the coefficients of partial correlation, each factor affecting to sediment was shown in order of gravel contents, number of first streams order, number of total streams, length of total streams, forest type, length of main stream, parent rock, stand age, soil texture, stream order, slope gradient, soil depth and aspect. Descriptions of class I were as follow; Igneous rock of parent rock, hardwood stands of forest type, less than 20 year of stand age, less than 30cm of soil depth, sandy clay loam of soil texture, more than 41% of gravel contents, south~east of aspect, 2,501~3,500m of length of main stream, 21~25 of number of total streams, 5,501~10,000m of length of total streams, 3 or more than 4 of stream order, more than 16 of number of first stream orders and more than $31^{\circ}$ of slope gradient. Descriptions of class II were as follow; Metamorphic rock of parent rock, coniferous stands of forest type, more than 25 year of stand age, 31~40cm of soil depth, silt loam of soil texture, 11~20% of gravel contents, north~west of aspect, 2,501~3,500m of length of main stream, 16~20 of number of total streams, 3,501~5,500m of length of total streams, 3 of stream order, 11~15 of number of first stream orders and more than $31^{\circ}$ of slope gradient. Descriptions of class III were as follow; Sedimentary rock of parent rock, mixed stands of forest type, more than 25 year of stand age, more than 51cm of soil depth, silty clay loam of soil texture, less than 10% of gravel contents, south~west of aspect, less than 500m of length of main stream, less than 5 of number of total streams, less than 1,000m of length of total streams, less than 1 of stream order, less than 2 of number of first stream orders and less than $25^{\circ}$ of slope gradient. The prediction method of suitable site for erosion control dam divided into class I, II, and III for the convenience of use. The score of class I evaluated as a very unstable area was more than 8.4494. A score of class II was 8.4493 to 6.0452, it was evaluated as a moderate stable area, and class III was less than 6.0541, it was evaluated as a very stable area.