• 제목/요약/키워드: Original forest

검색결과 219건 처리시간 0.019초

목타르계 페놀접착제의 제조 및 접착성능 (Manufacture of Wood Tar-based Phenol Adhesives and Adhesive Properties)

  • 박상범;김수원;박병대;한태형;강은창;박종영;문성필
    • 임산에너지
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    • 제24권1호
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    • pp.33-38
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    • 2005
  • 목탄의 제조과정에서 발생되는 목타르의 신용도를 찾고자 목타르를 이용한 레졸형 페놀수지접착제를 제조하여, 합판에 대한 접착력 시험을 실시하였다. 소나무타르계 접착제는 미첨가 페놀접착제와 비교했을 때, 고형분, 점도와 같은 수지의 물성은 유사하였으며, 인장 전단 접착력에서도 비내수, 내수 모두 페놀접착제에 비해 크게 떨어지지 않았다. 그러나, 참나무타르계 접착제의 경우에서는 수지물성도 페놀수지와는 다른 물성을 보였으며, 내수접착력은 페놀접착제의 접착력에 비해 절반 정도의 낮은 접착력을 보였다. 포름알데히드 방출량은 목타르의 첨가량이 많을수록 많이 방출되었다.

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Implementation of YOLOv5-based Forest Fire Smoke Monitoring Model with Increased Recognition of Unstructured Objects by Increasing Self-learning data

  • Gun-wo, Do;Minyoung, Kim;Si-woong, Jang
    • International Journal of Advanced Culture Technology
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    • 제10권4호
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    • pp.536-546
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    • 2022
  • A society will lose a lot of something in this field when the forest fire broke out. If a forest fire can be detected in advance, damage caused by the spread of forest fires can be prevented early. So, we studied how to detect forest fires using CCTV currently installed. In this paper, we present a deep learning-based model through efficient image data construction for monitoring forest fire smoke, which is unstructured data, based on the deep learning model YOLOv5. Through this study, we conducted a study to accurately detect forest fire smoke, one of the amorphous objects of various forms, in YOLOv5. In this paper, we introduce a method of self-learning by producing insufficient data on its own to increase accuracy for unstructured object recognition. The method presented in this paper constructs a dataset with a fixed labelling position for images containing objects that can be extracted from the original image, through the original image and a model that learned from it. In addition, by training the deep learning model, the performance(mAP) was improved, and the errors occurred by detecting objects other than the learning object were reduced, compared to the model in which only the original image was learned.

The Importance of Using Correct Names in Taxonomy - A Case Study of "The Genera of Vascular Plants of Korea" and Other Recent Published Literature in Korea

  • Chang, Kae Sun;Chang, Chin-Sung
    • 한국산림과학회지
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    • 제98권5호
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    • pp.524-530
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    • 2009
  • We scrutinized the Korean taxonomic literature, with special focus on some nomenclatural points and four different cases were listed categorically. Several naked names (nomen nudum), invalidly published names, typographical and orthographical errors, incorrect use of hybrid names and authorship, and errors in the citation of the bibliographic references have appeared in newly published literature in Korea, due to misapplications of ICBN (International Code of Botanical Nomenclature). Although literature review and synonyms are imperative and essential elements of taxonomic study, many author citations tend to be copied from one publication to another without any confirmation of the original source. It is strongly recommended that scientists who have previously published careless work should be more careful, and they should be instructed to read original descriptions and to learn current practices in the code.

목타르 혼합 페놀수지접착제의 접착성능 (Adhesive Properties of Phenol Resin Adhesive Mixed with Wood Tar)

  • 박상범;김수원;박병대;한태형;강은창;박종영;문성필
    • 임산에너지
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    • 제24권1호
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    • pp.28-32
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    • 2005
  • 목탄의 제조 과정 중 얻어지는 목타르의 활용방안을 모색코자 페놀수지에 목타르를 혼합하여 합판을 제조하여, 물리적, 기계적 및 포름알데히드 방출성능을 조사하였다. 목타르를 혼합하여 제조된 합판의 경우, 목타르를 혼합하지 않은 합판에 비해 물리적, 기계적인 면에서 별다른 감소를 보이지 않았으며, 인장전단 접착력은 비내수, 내수 모두 목타르의 혼합으로 인하여 오히려 향상되는 것으로 나타났다. 또한 포름알데히드 방출량에서도 목타르의 첨가는 방출량을 감소시키는 것으로 나타났다.

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황폐산지(荒廢山地)에서의 산불이 삼림식생(森林植生) 및 토양(土壤)에 미치는 영향(影響)에 관(關)한 연구(硏究)(IV) (Effects of Forest Fire on the Forest Vegetation and Soil(IV))

  • 우보명;이헌호
    • 한국산림과학회지
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    • 제78권3호
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    • pp.302-313
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    • 1989
  • 관악산(冠岳山) 암석산지(岩石山地)에서 지표화(地表火)가 발생(發生)한지 5년(年)이 경과(經過)한 후(後) 토양조건(土壤條件) 및 삼림식생(森林植生) 변화(變化)에 미친 영향(影響)을 밝히고자 1988년(年) 7월(月)에 실시(實施)한 조사결과(調査結果)는 다음과 같다. 유기물함량(有機物含量), pH, 전질소함량(全窒素含量)은 산불발생(發生) 후(後) 3년(年)까지는 증가(增加)를 나타낸 후(後) 안정(安定)을 보였다. 5년간(年間) 초본(草本), 목본식물(木本植物)의 상대우점치(相對優占値) 변동(變動)에 의하여 출현종(出現種)들을 산불에 민감종(敏感種), 내성종(耐性種), 수입종(侵入種), 무반응종(無反應種)으로 구분(區分)할 수 있었다. 종다양도지수(種多樣度指數), 유사도지수(類似度指數) 등(等) 다양성지수(多樣性指數)의 변동(變動)을 고려(考慮)할 때, 산불 후(後) 5년(年)동안에 종구성측면(種構成側面)의 회복(回復)은 이루어 졌으나 수관울한(樹冠鬱閑), 임목성장(林木成長) 등(等) 식생발달측면(植生發達側面)에서의 회복(回復)은 아직 이루어지지 않은 것으로 판단(判斷)된다.

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임도 개설 후 경과년수에 따른 식생 회복 경향 (Tendency for Vegetation Recovery Years after Forest Road Construction)

  • 이성연;윤충원
    • 한국산림과학회지
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    • 제113권3호
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    • pp.327-338
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    • 2024
  • 임도는 산림생태계의 물리·생물 환경의 퇴화를 초래할 수 있으나 산림 경영과 공익 기능에 반드시 필요한 시설이다. 일시적으로는 환경의 퇴화를 초래할 수 있고, 장기적으로는 다시 원생태계의 모습으로 회복될 수도 있어, 본 연구는 임도개설로 인한 산림생태계의 변화 과정을 파악하기 위하여 시간의 경과에 따른 생태계를 구성하는 식생군집구조의 변화를 조사·분석하였다. 조사구는 충청남도 부여군 일대 1998년(25년 경과), 2021(2년 경과), 2022년(1년 경과)에 개설된 임도를 대상으로 25m2 크기의 63개소{7횡단 조사구(상부 임분, 상부 임연부, 절토면, 임도면, 성토면, 하부 임연부, 하부 임분)×3개 벨트×3개 임도}를 선정하여 식물사회학적 방법으로 식생조사를 수행하였다. 연구결과, 조사구유형별 식생 분석을 통해 25년 경과 절성토에서 소나무와 굴참나무의 중요치가 교목층, 아교목층에서 대조구 수준으로 나타났으며 이는 원생태계의 구조와 기능이 어느 정도 회복된 것으로 판단되었다. 종다양도에서 절성토면과 임도면은 균재도가 높고 우점도가 낮게 나타났는데, 이는 새, 억새 등 일부 종의 우점도가 매우 높기 때문으로 판단되었다. 군락유사도와 DCA분석 결과, 대조구, 모든 임연부, 25년 경과 절성토와 그룹이 형성되었고, 모두 동일한 군락으로 볼 수 있었다. 결론적으로 25년 경과한 임도는 원생태계 수준으로 복원이 되어가는 과정에 있는 것으로 판단되었다. 이러한 연구 결과는 향후 임도 개설 예정지 및 개설지의 식생 회복과정에 대한 군집생태학적 유용자료로 활용될 수 있을 것이다.

Characterization of Burned Architectural Woods by Fire Using SEM-EDXS and Computerized Tomography

  • Lee, Hyun-Mi;Hwang, Won-Joung;Lee, Dong-Heub;Son, Dong-Won
    • Journal of the Korean Wood Science and Technology
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    • 제42권5호
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    • pp.516-522
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    • 2014
  • Old architectural wood materials damaged by a fire were evaluated on the basis of wood species and scanning electron microscopy (SEM) observation of wood tissues in combination with energy dispersive X-ray spectroscopy (EDXS) analysis. Results of SEM observation showed that tracheid wall thickness of burned parts was very thin compared with undamaged and sound wood, and tylosoid in the resin canals disappeared after the exposure to fire. SEM-EDXS analysis indicated that carbon and oxygen peaks occurred in the original energy band, and the carbon peak was higher than that of the oxygen in the burned part. A computerized tomography was also undertaken to investigate the carbonization layer formed by fire and possible internal defects.

도시생태네트워크 구축을 위한 도시공원의 연결성 평가 기초 연구 (A Basic Study on Connectivity of Urban Parks for the Urban Ecological Network Establishment)

  • 성현찬;김미리;황소영;김수련
    • 한국환경복원기술학회지
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    • 제17권2호
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    • pp.125-136
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    • 2014
  • Urban Green Area has ecologically deteriorated along with quantitative loss, being developed as a dot itself rather than connected to forests and green networks around the park. The present study aims to propose a connected plan on Urban Ecological Network establishment through 'assessment of the connectivity of the entire urban parks' in accordance with distance of forest and river and 'assessment of trends in connection fragmentation of urban parks' in accordance with the past change of forest and river. According to the result of this study, criteria based on previous research was "directly linked type is less than 300m, conceptually linked type is between 300m to 1km, the isolated type is greater than 1km". And the result of 'assessment of the connectivity of the entire urban parks' is analyzed as the rate of park and green network, 41.7% in Suwon, 80.0% in Seongnam, 88.9% in Namyangju on the basis of office and field investigation. Also, according to the result of 'assessment of trends in connection fragmentation of urban parks', consideration for connection to the original forest is insufficient.

Sound Absorption and Physical Properties of Carbonized Fiberboards with Three Different Densities

  • Lee, Min;Park, Sang-Bum;Byeon, Hee-Seop
    • Journal of the Korean Wood Science and Technology
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    • 제42권5호
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    • pp.555-562
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    • 2014
  • Characteristics of carbonized fiberboard such as chemical materials absorption, electromagnetic shielding, and electrical and mechanical performance were determined in previous studies. The carbonized board therefore confirmed that having excellent abilities of these characteristics. In this study, the effect of density on physical properties and sound absorption properties of carbonized fiberboards at $800^{\circ}C$ were investigated for the potential use of carbonized fiberboards as a replacement of conventional sound absorbing material. The thickness of fiberboards after carbonization was reduced 49.9%, 40.7%, and 43.3% in low density fiberboard (LDF), medium density fiberboard (MDF), and high density fiberboard (HDF), respectively. Based on SEM images, porosity of carbonized fiberboard increased by carbonization due to removing adhesives. Moreover, carbonization did not destroy structure of wood fiber based on SEM results. Carbonization process influenced contraction of fiberboard. The sound absorption coefficient of carbonized low density fiberboard (c-LDF) was higher than those of carbonized medium density fiberboard (c-MDF) and carbonized high density fiberboard (c-HDF). This result was similar with original fiberboards, which indicated sound absorbing ability was not significantly changed by carbonization compared to that of original fiberboards. Therefore, the sound absorbing coefficient may depend on source, texture, and density of fiberboard rather than carbonization.

Effect of Silvicultural Treatments on Carbon Storage of Northern Hardwood Forests

  • Park, Byung Bae;Kim, Young Kwan;Lee, Sang Ick
    • 한국산림과학회지
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    • 제96권2호
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    • pp.208-213
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    • 2007
  • This study is designed to provide forest managers and landowners with tools to estimate the effect of forest management on carbon storage, investigating living tree biomass, detritus, and harvested wood products as variables. Thinning, selection cutting, and uncutting were applied to the three different forest types in New York, USA. Carbon storage of the original stands was 90, 56, and $101Mg\;ha^{-1}$ at the Allegheny hardwood forest, Northern hardwood forest, and Oak - black cherry forest, respectively. Among treatments, uncutting generally stored the greatest amount carbon. However, the rate of carbon storage was the smallest at the uncut treatment in all the sites. The 50% thinning, 50% selection, and 50% thinning treatments were the highest rate of carbon storage at the Allegheny hardwood forest, Northern hardwood forest, and Oak - cherry forest, respectively. In this study, only short term was applied to simulate carbon sequestration after silvicultural treatment. So, more research is needed to determine whether any silvicultural treatment can store significantly more carbon than no treatment over the long term.