• 제목/요약/키워드: FOREST EDGE

검색결과 174건 처리시간 0.026초

바이올린용(用) 소재(素材)의 진동모드 해석(解析)에 관한 연구사 - 제1보. 절삭방향 및 밀도에 따른 공진 주파수의 변화 (Studies on the Vibrational Modal Analysis of Solid Woods for the Violin Making - Part 1. Effect of Cutting Direction and Density on Resonant Frequency of Woods)

  • 정우양;박선행
    • Journal of the Korean Wood Science and Technology
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    • 제27권3호
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    • pp.1-6
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    • 1999
  • 복잡한 구조를 지니는 바이올린 동체 설계 및 음질 평가률 위한 기본정보를 마련코자 바이올린 주요소재인 European spruce 및 European maple의 강제진동(强制振動) 의한 선형(線型) 휨진동(振動) 모드를 조사하고 소재밀도 및 절삭방향에 따른 진동모드별 공진(共振)주파수 변위를 분석하였다. 연구 결과 저비중재임에도 불구하고 spruce가 maple에 비해 더 높은 공진(共振) 주파수률 지님으로써 보다 우수한 음향특성을 지니는 것으로 나타났다. 또 spruce의 경우 접선방향으로 절삭된 판목재에 비해 방사방향 절삭된 정목재의 주파수 편차가 작아 균일한 음질을 위해서는 전반(前板)주요부품 가공시 정목판재를 사용하는 것이 바람직한 것으로 판단되었다. 그리고 두 수종 공히 소재밀도와 공진(共振)주파수간의 관계는 양의 상관관계를 나타냈으며, 절삭방향별로는 정목재의 상관계수가 판목재에 비해 놓게 나타났다.

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골판지 불량 검색 시스템 개발, 현장적용과 생산 불량률 변화 (Development of Defects Detecting System for Corrugated Board, Mill Application, and Changes of Production Defects Ratio)

  • 정진모;민경은;김문성;박종문
    • 펄프종이기술
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    • 제40권2호
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    • pp.37-42
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    • 2008
  • Defects of corrugated board were limiting factors to the corrugated industry's growth. On-line detecting systems of defects are beneficial to increase profits of the corrugated board companies by reducing base paper consumption, increasing process reliability, and increasing productivity. By replacing naked eye inspection of defects to a defects detecting system, continuous inspection without fatigue may guarantee final products quality. The system was developed, which was consisted of line scan CCD camera, lens, illuminating parts, high speed image processor, software, various input parts, and output parts. First installation location of the system was at before fluting process after base paper unwinding, and surface of liner board was inspected by the system. Second installation location was after fluting process and combining process for liner board. Production loss includes ragged appearance of edge, irregular flute shape, wrong combination of flute, score cracking, defects in base paper, and flute cracking. The production loss was analyzed before and after the system installation at a commercial domestic mill. The production loss ratio was defined as a production loss weight per total production weight. The production loss ratio before the installation was decreased a lot from 1.28%(during 3 months before installation) to 0.76%(during 12 months after the first installation) and to 0.25%(during 6 months after the second installation).

오대산(烏臺山) 아고산대(亞高山帶)의 자생(自生) 초본식물(草本植物) 분포(分布)와 입지인자(立地因子)에 관한 연구(硏究) (A Study on the Relationship between the Distribution of Native Herb Species and Site Factor's at Subalpine Zone in Mt. Odae)

  • 김갑태
    • 한국산림과학회지
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    • 제87권3호
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    • pp.459-465
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    • 1998
  • 이 연구(硏究)는 자생(自生) 초본식물(草本植物)의 보존(保存)과 임한재배(林閒裁培)에 필요한 기초자료(基礎資料)를 얻고자, 오대산(烏臺山)의 동대산, 두로봉, 상왕봉, 비로봉을 잇는 아고산대(亞高山帶)를 중심으로 자생(自生)하는 초본식물(草本植物)의 분포(分布)와 입지인자(立地因子)를 조사(調査)하고 상호관련성(相互關聯性) 분석(分析)하였다. 단풍취, 큰개별꽃 및 참나물은 관엽수혼효림(關葉樹混淆林)에 주로 분포(分布)하며, 요강나물, 대사초, 오리방풀 및 나비나물은 갭에 주로 분포(分布)하는 것으로 나타났다. 사면(斜面) 방위별(方位別) 분석(分析)에서는 곰취, 진범, 박쥐나물 및 넓은잎외잎쑥은 유의차(有意差)가 인정(認定)되었다. 넓은잎외잎쑥은 남향 사면에 많이 분포(分布)하며, 곰취, 진범 및 박쥐나물은 북향이나 서향에서 많이 분포(分布)하였다. 토양수분(土壤水分) 조건별(條件別) 분석(分析)에서는 진범과 넓은잎외잎쑥에서 유의차(有意差)가 인정(認定)되었다. 넓은잎외잎쑥은 건조한 입지(立地)에 많이 분포(分布)하며, 진범은 토양수분 조건이 좋은 곳에 많이 분포(分布)하였다. 수관울폐도(樹冠鬱閉度)와의 상관관계(相關關係)에서는 요강나물, 대사초, 오리방풀, 나비나물 등이 부(負)의 상관(相關)을 보였다. 진범, 참나물, 벌깨덩굴, 풀솜대 및 큰개별꽃 등은 다소 습한 숲그늘을 선호(選好)하고, 송이풀, 요강나물 및 넓은잎외잎쑥 등은 햇빛이 잘 드는 숲 가장자리나 개활지(開豁地)를 선호(選好)하는 것으로 나타났다.

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Application of Deep Learning: A Review for Firefighting

  • Shaikh, Muhammad Khalid
    • International Journal of Computer Science & Network Security
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    • 제22권5호
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    • pp.73-78
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    • 2022
  • The aim of this paper is to investigate the prevalence of Deep Learning in the literature on Fire & Rescue Service. It is found that deep learning techniques are only beginning to benefit the firefighters. The popular areas where deep learning techniques are making an impact are situational awareness, decision making, mental stress, injuries, well-being of the firefighter such as his sudden fall, inability to move and breathlessness, path planning by the firefighters while getting to an fire scene, wayfinding, tracking firefighters, firefighter physical fitness, employment, prediction of firefighter intervention, firefighter operations such as object recognition in smoky areas, firefighter efficacy, smart firefighting using edge computing, firefighting in teams, and firefighter clothing and safety. The techniques that were found applied in firefighting were Deep learning, Traditional K-Means clustering with engineered time and frequency domain features, Convolutional autoencoders, Long Short-Term Memory (LSTM), Deep Neural Networks, Simulation, VR, ANN, Deep Q Learning, Deep learning based on conditional generative adversarial networks, Decision Trees, Kalman Filters, Computational models, Partial Least Squares, Logistic Regression, Random Forest, Edge computing, C5 Decision Tree, Restricted Boltzmann Machine, Reinforcement Learning, and Recurrent LSTM. The literature review is centered on Firefighters/firemen not involved in wildland fires. The focus was also not on the fire itself. It must also be noted that several deep learning techniques such as CNN were mostly used in fire behavior, fire imaging and identification as well. Those papers that deal with fire behavior were also not part of this literature review.

Creation of an Environmental Forest as an Ecological Restoration

  • Lee, Chang-Seok;You, Young-Han
    • The Korean Journal of Ecology
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    • 제24권2호
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    • pp.101-109
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    • 2001
  • We created an environmental forest on the basis of ecological design around the incineration plant of Jindo Engineering and Construction Co., Ltd., which is located in Jeongwang-dong, Siheung-si, Kyunggi-do. To get ecological information of this site, physico-chemical properties of soil on salt marsh, which is located close to the syudy site and of forest soil transported from other sites for ecological restoration were analyzed. Texture of salt marsh and transported soils were loam and sandy loam, respectively. pH, organic matter, T-N, available P, and exchangeable K and Na contents of salt marsh and transported forest soils were 6.7 and 5.4, 4.1 and 0.4%, 1.0 and 0.3mg/g, 46.7 and 6.8ppm, 521 and 207ppm, and 3.8 and 0.5mg/g, respectively. Introduced plants were selected among the dominant species of forests and the species composing the potential natural vegetation around the present study site. Those plants were selected again by considering the tolerances to air pollution and to salt, and their availability. Selected trees were Pinus thunbergii, Sophora japonica, Celtis sinensis, Quercus aliena, Q. serrata, Q. dentata, and Q. acutissima. Selected sub-trees were Albizzia julibrissin, Koelreuteria poniculata, and Styrax japonica and shrubs were Rhododendron yedoense var. poukhanense, R. mucronulatum, Callicarpa japonica, Euonymus alatus, E. japonica, and R. schlippenbachii. On the other hand, introduction of herbs was not considered except for Liriope platyphylla, which was ornamentally planted in one site. Planting bed of mound type was adopted to provide the fine drainage system. Mound was designed to furnish litter, A, B, and C layers simuating the profile of forest soil. Slope of mound was mulched by rice straw of 2cm in thickness to prevent for sliding of litter and soil in cases of strong wind or heavy rain. Height of mound was designed to secure more than 1 m by combining A and B layers. Narrow zones, in which mound with stable slope degree cannot be prepared, was designed to equip the standard soil depth with the introduction of stone for supporting. On the other hand, plants with shallow root system were arranged in some zones, in which satisfactory soil depth cannot be ensured. Plants were arranged in the order of tree, sub-tree, and shrub from center to edge on the mound to make a mature forest of a dome shape in the future. Dispersion of plants was designed to be random pattern rather than clumped one. Problems on creation of the environmental forest by such ecological design were found to be management or inspection by non-specialized project operators and inspecting officers, and regulations for construction without ecological background. Alternative plans to solve such problems were suggested.

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휴석동(休石洞) 땅밀림형(型) 산사태(山沙汰)의 발생특성(發生特性)에 관한 연구(硏究)(I) -지형(地形) 및 지표이동특성(地表移動特性)- (A Study on the Characteristics of the Landslide in Hyuseok-dong(I) -Topographical Characteristics and Surface Displacement-)

  • 우보명;박재현;최형태;전기성;김경훈
    • 한국산림과학회지
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    • 제85권4호
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    • pp.565-570
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    • 1996
  • 충청북도(忠淸北道) 단양군(丹陽郡) 영춘면(永春面) 상리(上里) 휴석동(休石洞) 땅밀림형 산사태지(山沙汰地)에 대한 지형(地形) 및 지표이동특성(地表移動特性)을 조사 분석한 결과, 연구대상지에는 골락애(滑落崖), 인장균열(引張龜裂) 및 요지(凹地)와 계단상(階段狀) 지형(地形)이 여러 곳에 형성되어 있었다. 또한, 마을진입 횡단도로(橫斷道路)(구역 횡단도로)의 변형 및 건물(建物)(잠사(蠶舍)), 배수로(排水路) 등의 파괴와 수목(樹木)의 도복(到伏) 경도 (傾到) 등과 같은 땅밀림 산사태(山沙汰) 발생(發生)의 징후(徵候)가 현저하였다. 휴석동(休石洞) 산사태(山沙汰)의 이동토괴(移動土塊)는 주로 남동(南東)~남동동(南東東) 방향(方向)으로 이동하고 있으며, 이동토괴(移動土塊) 중심부의 지표이동량(地表移動量)은 월평균 약 17.6cm, 지표침하량(地表沈下量)은 연간 약 88.5cm인 것으로 분석되었다. 연구대상지 최하단부(最下端部)의 포락(浦落)벼랑은 7개월간(1995년 6월~12월) 깊이 0.823m의 토사가 침식된 것으로 측정되었으며, 전체 포락(浦落)벼랑에서 $4,938m^3$의 토사(土砂)가 남한강(南漢江)으로 유실(流失)된 것으로 나타났다. 휴석동(休石洞) 산사태(山沙汰)는 광범위한 면적에서 대규모로 발생되고, 특히 여름철 장마 홍수때에 이동량(移動量)이 급격히 증대하였으며, 이동토괴(移動土塊)의 이동속도 및 남한강변의 포락침식량을 고려하여 볼 때, 향후(向後) 산사태 재해의 발생이 우려되는 지역으로 분석되었다.

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기존 송이 균환(菌環)을 이용한 송이균 감염 소나무의 생산 및 이식 (Production and Transplanting of Ectomycorrhizal Pine Seedlings Using the Old Fairy Ring of Tricholoma matsutake)

  • 가강현;허태철;박현;김희수;박원철;윤갑희
    • 한국산림과학회지
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    • 제95권6호
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    • pp.636-642
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    • 2006
  • 야외에서 새로운 송이균환을 만들기 위하여 2000년부터 2005년까지 소나무를 이용한 송이 감염묘 생산과 이식 및 이식 후 송이 균의 활착을 높일 수 있는 방법을 연구하였다. 송이 간염묘 생산을 위해서는 11월에 균환 선단에 심을 경우 활착률 97%를 나타낸 반면 4월에 심을 경우에는 활착률이 80%를 나타냈다. 송이균의 감염은 식재 후 2년 이상 경과하여야 완전히 이루어지는 것으로 나타났으며, 천연치수를 이용한 경우는 17.6%의 송이균 생존률을 나타낸 반면, 양묘를 이용한 경우는 송이균의 생존율이 극히 낮았다. 한편, 생산된 감염묘의 이식 시 송이균의 생존율은 4월에 이식할 경우 22%, 10월과 11월에 이식할 경우에는 5%를 나타냈다. 이식한 송이 감염묘에서 송이균의 생존은 이식전 50% 내외의 송이균 감염율을 가진 감염묘가 가장 높은 생존율을 니타냈다. 이식한 송이 감염묘에서 송이균의 생존 여부 확인을 위하여 송이 감염묘를 완전히 파내어 확인하는 방법은 살아있던 송이균도 이후에 사멸하게 되는 원인이 되었다. 이에 따라 이식한 감염묘의 송이균 확인은 색대를 이용하는 방법을 도입하였으며, 이식 후 2년 이상 경과한 후에 검정하는 것이 송이균의 생존에 유리할 것으로 판단되었다.

Vegetation and flora of Hibiscus hamabo inhabited naturally in Soan Island

  • Ahn, Young-Hee;Chung, Kyu-Hwan;Park, Hee-Seung
    • 한국환경과학회지
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    • 제12권11호
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    • pp.1181-1187
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    • 2003
  • Hibiscus hamabo, called "Hwang-geun", growing about 3m in height is a deciduous shrub or subtree of Malvaceae. Because the number of these species is very limited in the world, the Ministry of Environment has designated H. hamabo as a preserved plant. The Korea Forest Service also protects it strictly by law since H. hamabo is an out-of-the-way plant and possibly may be exterminated soon in Korea. Investigation for distribution and ecological characteristics of the habitat for H. hamabo was carried out on Soan Island. Two wild H. hamabo were found at the forest edge (equation omitted) along the sea coast located in the southern part of Soan Island and this was the first report in the Korean academic world. These two wild H. hamabos were growing in a naturally inhibited area. The diameters at the base were 12cm and 15cm. The Tree heights were 150cm and 210cm and the number of branches of each wild H. hamabo was 4 and 7. However, the present condition of these plants was not good. Environmental conditions of the naturally inhibited area of H. hamabo were very mild because it is located at the edge of the forest and is always sunny during the daytime since the slope of the inhibited area is facing South. The ground drained very well since the soil was made of gravels and sand. Because the percent of vegetation of the subtree layer where H. hamabo was growing was 40%, the cover degree and sociability of flex crenata trees and Eurya japonica were found to be high. In the naturally inhibited area of H. hamabo, a dominant value of Rubus parvifolius in the lower part of the herb layer was very high and many plants in Compositae, such as Artemisia princeps var. orientalis and Erigeron annuus, were also present. A dominant value of liana, such as Vitis thunbergii var. sinuata, Rosa multiflora, Clematis terniflora and Hedera rhombea, and Gramineae plants that rhizomes were well developed and aggressively propagated, such as Miscanthus sinensis var. purpurascens, Phragmites communis, Spodiopogon cotulifer and Oplismenus undulatifolius which were surveyed as high, too. These results imply that H. hamabo might be exterminated soon through a natural selection if the proper management of the naturally inhibited area of H. hamabo is not conducted continually.

Leachability of Zinc Borate-Modified Oriented Strandboard (OSB)

  • Lee, Sun-Young;Wu, Qinglin
    • Journal of the Korean Wood Science and Technology
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    • 제35권5호
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    • pp.46-57
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    • 2007
  • The leachability of boron in zinc borate (ZB)-modified oriented strandboard (OSB) from southern wood species was investigated in this study. The leaching experiments were conducted by exposing edge-sealed OSB samples under running water at $31^{\circ}C$ for 8, 24, 72, and 216 h. The results from leached samples were compared with those from the unleached controls. Boron leaching of the modified OSB occurred upon the initial water exposure, and the leaching rate decreased as the leaching time increased. Initial boric acid equivalent (BAE) level, wood species, and sample thickness swelling significantly influenced the leachability. There was no consistent effect of polyethylene glycol (PEG) on zinc borate leaching. The glue-line washing within OSB due to thickness swelling of the test samples under water and decomposition of the borate to form water-soluble boric acid were thought to be two possible causes for the observed leaching. The relationship between assayed BAE and leaching time followed a decaying exponential function for zinc borate treated OSB. From the boron/zinc ratio after each leaching period, boron element in ZB was more or less leachable. The material constant of the regression models allowed comparing the leachability of the modified OSB for various wood species. An unified leaching method for treated wood composite materials is needed.

경관지수를 활용한 식생군락 모자이크화 분석법 (Development of an Approach for Analysing Vegetation Community Mosaic Using Landscape Metrics)

  • 이상훈;정종철
    • 지적과 국토정보
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    • 제47권1호
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    • pp.161-178
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    • 2017
  • 한국 국토의 60% 이상을 차지하고 있는 산림지역에 대한 개발과 이용의 수요가 증가하고 있지만, 개발사업의 허가는 산림생태계의 보전보다는 국토 이용 중심의 평가로 이루어지고 있다. 대규모 산림지역을 평가할 경우 산림의 구조를 중심으로 분석하기 때문에 산림 내부의 변화를 관찰하고 분석하는데 한계가 있다. 따라서 본 연구에서는 충청남도 식생군락의 현존식생도와 FRAGSTATS 4.2를 이용하여 경관지수를 산출하고 식생 모자이크를 분석해 보았다. 식생 군락은 주요 자생 수종을 중심으로 대표군락과 세부군락으로 구분하였고, 군락별 차이를 분석하기 위해 분포면적(CA), 분포면적비율(PLAND), 패치개수(NP) 등의 10가지 경관지수가 선택되었다. 충청남도 식생의 대표군락과 세부군락은 소나무군락, 상수리나무군락 및 소나무와 참나무류 수종의 조합이 우세하게 나타났으며, 소나무군락의 면적이 상당히 높게 나타났다. 소나무군락과 참나무류군락의 경쟁의 경우, 대표군락의 경우 소나무군락이 전체 분포면적은 3배 가량 넓으나 작은 패치로 나뉘어져 모자이크화 정도는 참나무류 군락이 작은 것으로 판단되었다. 세부군락의 경우에는 소나무 중심의 군락에서는 소나무-신갈나무군락이, 상수리나무 중심 군락에서는 상수리나무군락이, 굴참나무 중심의 군락에서는 굴참나무-소나무군락이, 신갈나무 중심의 군락에서는 신갈나무군락이, 곰솔 중심의 군락에서는 곰솔군락이, 졸참나무 중심의 군락에서는 졸참나무-상수리나무군락이 넓은 분포면적과 동시에 모자이크화도 심한 것으로 나타났다. 전체적인 모자이크화 양상은 수치로 표현될 수 있어 모니터링 단계에서 문제가 있는 식생군락을 판별할 때 유용할 것으로 판단되었다. 모자이크화의 원인과 천이의 방향성 예측을 통한 관리 방안 마련을 위해서는 각 군락의 생태적인 특성에 대한 연구가 추가적으로 필요할 것으로 판단되었다.