• 제목/요약/키워드: B+-Tree

검색결과 1,004건 처리시간 0.03초

Erosion Control Effect by Soil ansi Vegetation Transition in Mountainous Area after Soil Erosion Measures were Initiated (토양 및 식생변화에 따른 토지 사방 공사의 효과에 관한 연구)

  • 이천용
    • Journal of the Korean Institute of Landscape Architecture
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    • 제14권2호
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    • pp.7-16
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    • 1986
  • This study was carried out to investigate the effects of such erosion control measures as sowing, planting and small earth structures on the soil and vegetation. In order to study the changes in soil and vegetation, 36 plots were surveyed from 1981 to 1982 in the large erosion control area which is restored last 20 years. The factors which were measured included vegetation coverage, tree growth, number of species, soil depth, soil consistancy, and Chemical properties of soil. The results were as follows; 1) Maximum coverage of the overstory and understory was attained 7 years after the initiation of erosion control. So the overstory need to be tended and pruned. 2) Diversity of species increased until age 6 after which it began to decrease. 3) In order of tree growth, black locust was the fastest, followed by siberian alder and pitch pine. The initial growth of black locust, though the best among the 3 tree stop., decreased rapidly year by year. At the same time, siberian alder and pitch pine grew well until 12 and 6 years after the initiation of erosion control respectively. 4) Fifty percent of the initially planted trees died within 8 yeard. The mortality of siberian alder occurred until the 20th year while the mortality of pitch pine stopped after 10 years. Thereafter 500 trees per hectare were maintained. 5) The soil depth in A and B horision increased by 2cm annually during 20 years. The soil consistency also decreased rapidly until 7th year. The physical soil properties of the rehabilitated areas were improved after the 14th year. 6) The soil pH tend to decrease from 5.3 during the first year to 5.1 during the twentieth year. 7) The organic matter and nitrogen content in the soil were increased by fertilization but after 20 years these nutrients are still deficient for normal tree growth. 8) The phosphorous content in the soil was high in the first year but the longer the period after the initiation of erosion control the lese the content of phosphorous. 9) The biomass of black locust was the highest and increased continuously. The biomass of siberian alder on the contrary decreased from the 15th year because the number of trees in this place was very low. The total biomass in the twentieth year after erosion control initiation was 105.7 ton per hectare.

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Fundamental Economic Feasibility Analysis on the Transition of Production Structure for a Forest Village in LAO PDR (라오스 산촌마을의 생산구조전환을 위한 투자 경제성 기초 분석)

  • Lee, Bohwe;Kim, Sebin;Lee, Joon-Woo;Rhee, Hakjun;Lee, Sangjin;Lee, Joong-goo;Baek, Woongi;Park, Bum-Jin;Koo, Seungmo
    • The Journal of the Korean Institute of Forest Recreation
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    • 제22권4호
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    • pp.11-22
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    • 2018
  • This study analyzes the economic feasibility on the transition of production structure to increase income for a local forest village in Laos PDR. The study area was the Nongboua village in Sangthong district where the primary product is rice from rice paddy. Possible strategies were considered to increase the villagers' revenue, and Noni (Morinda citrifolia) was production in the short-term. We assumed that the project period was for 20 years for the analysis, and a total of 1,100 Noni tree was planted in 1 ha by $3m{\times}3m$ spacing. This study classified basic scenario one, scenario two, scenario three by the survival rate and purchase pirce of Noni. Generally Noni grows well. However, the seedlings' average survival rate (= production volume) was set up conservatively in this study to consider potential risks such as no production experience of Noni and tree disease. The scenario one assumed that the survival rate of Noni seedlings was 50% for 0-1 years, 60% for 0-2 years, and 70% for 3-20 years; the scenario two, 10% less, i.e., 40%, 50%, and 60%; and the scenario three, 10% less, i.e., 40%, 50%, 60% and purchase price 10% less, i.e., $0.29 to $0.26, respectively. Our analysis showed that all 3 scenarios resulted in economically-feasible IRR (internal rate of return) of 24.81%, 19.02%, and 16.30% of with a discounting rate of 10%. The B/C (benefit/cost) ratio for a unit area (1ha) was also analyzed for the three scenarios with a discounting rate of 10%, resutling in the B/C ratio of 1.71, 1.47, and 1.31. The study results showed that the Nongboua village would have a good opportunity to improve its low-income structure through planting and managing alternative crops such as Noni. Also the results can be used as useful decision-making information at a preliminary analysis level for planning other government and public investment projects for the Nonboua village.

Genetic Variation of Isozymes in Populations of Pinus densiflora and Pinus thunbergii Naturally Distributed in Kyungpook Province (경북지방(慶北地方) 소나무 및 곰솔집단(集團)의 동위효소(同位酵素)에 의한 유전변이(遺傳變異))

  • Son, Doo-Sik;Hong, Sung-Chun;Yeo, Jin-Kie;Ryu, Jang-Bal
    • Journal of Korean Society of Forest Science
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    • 제78권4호
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    • pp.345-359
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    • 1989
  • This study was conducted to estimate genetic variation of Pinus densiflora in Kyungpook province which shows morphological variation between northern and southern types. Six isozymes sueh as IDH, ME, PGI, ADH, GOT and LAP was analyzed using megagametophyte tissue of seeds by electrophoresis and 16 populations of Pinus densiflora and 5 of Pinus thunbergii were tested. The results obtained were as follows ; 1. In P. densiflora, 13 Loci were found in 6 isozymes and 8 loci of them were polymorphic, having 24 alleles, while in Pinus thunbergii, there were 18 alleles detected from 6 loci among the same number of loci as in Pinus densiflora. 2. The genotypic frequency in Pinus densiflora vary slightly among populations for some isozymes, but most of them satisfied the law of Hardy-Weinherg equilibrium, while some populations such as Youngil for ADH and LAY, Youngyang for ADH and Bonghwa for LAY did not follow the law and showed high fixation index values and homozygosities higher than expected. 3. The variation among populations based on the genetic distance was small except populations of Youngju, Baegam, Gyungju and Sangju, however they could be clustered by three groups : northern Kyungpook group including Mt. Taebak, inland Kyungpook group represented by Sungju, Eusung and Kumleung population and coastal Kyungpook group represented by Baegam and Gyungju population. 4. No significant difference was found in 6 isozymes between northern and southern types of Pinus densiflora which was morphologically different. 5. The frequency of heterozygous loci per tree was higher in Pinus densiflora especially for ME-A and A DH-B, while that of homozygous loci was higher in Pinus thunbergii except for ADH-B, LAY-B and PGI-B locus.

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Development of Weight Estimation Equations and Weight Tables for Larix kaempferi and Pinus rigida Stand (일본잎갈나무와 리기다소나무의 중량추정식 및 중량표 개발)

  • Jintaek Kang;Chiung Ko;Jeongmuk Park;Jongsu Yim;Sun-Jeong Lee;Myoungsoo Won
    • Journal of Korean Society of Forest Science
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    • 제112권4호
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    • pp.472-489
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    • 2023
  • This study was conducted to derive the optimal estimation equations for deriving the green and dry weights of Larix kaempferi (Japanese larch) and Pinus rigida (Rigida pine), which are major coniferous tree species in South Korea. The equations were then used to develop weight tables. Table development began with the sampling of 150 L. kaempferi and 90 P. rigida trees distributed throughout the national scale, after which green weights were measured on-site. Samples from each stand were then collected, and their dry weights were measured in a laboratory. The equation used to calculate green and dry weights was divided into a one-variable formula that uses only the diameter at breast height (DBH) and a two-variable equation that employs DBH and height. The equations used to estimate the green and dry weights of logs were divided into one- and two-variable equations using DBH. Statistical data, such as the fitness index (FI), root mean square error, standard error of estimation, and residual diagram, were used to verify the suitability of the estimation equations. Applicability was examined by calculating weights using the derived optimal equations. The equation W = bD+cD2 was used in measurements involving only DBH, whereas the equation W = aDbHc was employed in cases involving both diameter and height at breast height. The FI of W = bD+cD2 was 0.91, while that of W = aDbHc was 0.95, both of which are high values. With these estimation formulas, weight tables for the green and dry weights of L. kaempferi and P. rigida were prepared and compared with weight tables created 20 years ago. The green and dry weight tables of both species were larger.

Physiological Tolerance of Native Tree Species in Abandoned Coal Mine Spoils (탄광 폐석지내 자생 수종의 생리적 피해 및 내성)

  • 이재천;한심희;장석성;김판기;허재선;염규진
    • Korean Journal of Agricultural and Forest Meteorology
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    • 제5권3호
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    • pp.172-178
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    • 2003
  • This study was conducted to assess the physiological tolerance of native tree species for successful restoration and revegetation of abandoned coal-mine spoils. Study sites were two coal-mine spoils (Sododong and Ssarijae) in Taebaek, Kangwon Province, Korea. Five individuals of Betula costata and of B. schmidtii were analyzed for malondialdehyde (MDA) and hydrogen peroxide ($H_2O$$_2$) content, nitrate reductase (NR) and superoxide dismutase (SOD) activity, and for carbohydrate concentration in the leaves. Trees in the abandoned coal-mine spoils were influenced by deficiencies expressed by MDA and $H_2O$$_2$ content in the leaves of two species being higher at the coal-mine spoils than in the surrounding forest. Low NR activity indirectly represented nitrogen deficiency in the soil of the coal-mine spoils; an unmanageable SOD activity implied that tolerant functions didn't net against a certain stress of the coal-mine spoils. Decreased glucose and increased starch concentration especially showed the inhibition of the carbohydrate metabolism by inadequate factors. Consequently, low nitrogen content in the real-mine soils might increase damage in trees as a result of inhibiting the expression of tolerance mechanisms against stress. Therefore, trees in coal-mine spoils need ample nitrogen to use as a metabolic energy source in order to prevent damage and increase tolerance against stress.

Prediction of Carcass Yield by Ultrasound in Hanwoo (초음파 측정에 의한 한우의 도체육량 예측)

  • Rhee, Y. J.;Jeon, K. J.;Choi, S. B.;Seok, H. K.;Kim, S. J.;Lee, S. K.;Song, Y. H.
    • Journal of Animal Science and Technology
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    • 제45권2호
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    • pp.335-342
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    • 2003
  • This study was conducted to predict the carcass yield traits using ultrasound before slaughter and to enhance the prediction accuracy of carcass yield grade by applying various strategies. For this experiment, five hundred seventy three Hanwoo steers of 24 months of age were used. Difference between ultrasound result and carcass measure of BFT and LMA was 0.6$\pm$1.65mm and 0.7$\pm$5.56cm2, respectively. Correlation coefficient between ultrasound result and carcass measure of BFT and LMA was 0.86 and 0.82, respectively (p<0.001). Results for improving predictions of yield grade by four methods-the Korean yield grade index equation, fat depth alone, regression and decision tree methods were 80.3%, 81.3%, 80.1% and 81.8%, respectively. We conclude that the decision tree method can easily predict yield grade and is also useful for increasing prediction accuracy rate.

Phylogeny of the subfamily Salmoninae distributed in Korea based upon nucleotide sequences of mitochondrial ribosomal RNA genes (미토콘드리아 ribosomal RNA 유전자 염기서열분석에 의한 한국산 연어아과 어류의 유전적 계통도)

  • LEE Heui-Jung;PARK Jung-Youn;LEE Jeong-Ho;MIN Kwang-Sik;JEON Im Gi;YOO Mi-Ae;LEE Won-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • 제33권2호
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    • pp.103-109
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    • 2000
  • Complete senuences of the mitochondrial rRNA Benes were determined among six salmonines in Korean Waters (Brachpmystax lenok, Onoorhpchus keta, O. masou mason, O. mason ishikawae, O. mykiss, and albino mutant of O. mykiss). The purposes of this study were to provide the basic information on levels of mtDNA polymorphism among these species for genetic characterization; discuss phylogentic relationships among three Oncorhynchus sepecies; demonstrate the utility of rRNA gene sequence data as a genetic marker for disringuishinf among Korean salmonines. PCR/direct sequencing data indicated the following consistent results; 1) 12S rRNA genes was 945 bases long in Oncorhynchus species, and 946 bases in B. lenot including one insertion. 2) Of sequence variation in mitochondrial rRNA regions, transitional substitutions were superior to transversion. 3) The significant differences were not shown in the intraspecific variation values in these gene regions. The percentage sequence divergence values were ranged from $0.066 to 0.212{\%}$. 4) The interspecific divergences were greater than the intraspecific variation. Nevertheless, ribosomal RMh genes were more conserved among species than the other mitochondrial genes, and they showed potentiality as an intergenic marker for systematics. In addition, phylogenetic trees, constructed from this data, supported that cherry salmon was closer to chum salmon than to rainbow trout, and that lenok was most distantly related species in six salmonid species.

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Repeated Reading Experience of Senior High School Girl: Centered on Jeonju Girls' High School Freshmen (여고생들의 반복독서 경험에 관한 연구 - 전주여고 1학년 학생들을 중심으로 -)

  • Lee, Seung-Chae
    • Journal of Korean Library and Information Science Society
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    • 제39권2호
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    • pp.313-332
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    • 2008
  • The goal of this study is to examine what sort of books girl's high school students read repeatedly, what are the different preferences between high school and university students. how much the repeatedly-read books are related to the most memorable books and how the repeatedly-read books are connected to reading habits. A questionnaire was provided to Jeonju Girls' High School Freshmen and their repeated reading experiences were searched. The results of the statistical analysis are summarized: 1) Most girls' high school students have experienced repeated reading more than twice. 2) The number of girls' high school students who have experienced repeated reading twice is the highest and next. those who have read repeatedly 3 times. Also, the number of times of repeated reading tends to be similar between woman high school and College students. 3) The books which many students read repeatedly more than twice are : a) Little Prince b) The Myth of Greece and Rome c) Chinese nine spine stickle back d) Meu Pe de Larania Lima e) Giving Tree f) Harry Potter. 4) About half of the students have read the most memorable books many times. 5) The importance of books was evaluated on the basis of the number of repeated readers and the number of readings. The order of the important books is Little Prince, The Myth of Greece and Rome, Harry Potter, Giving Tree, Meu Pe de Larania Lima, Chinese Nine Spine Stickle Back.

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Comparison of Lentinula edodes Growth Characteristics According to the Amount of Paper Mulberry Sawdust Added (닥나무 톱밥 첨가량에 따른 표고 생육특성 비교)

  • Jeong, Yeun Sug;Jang, Yeongseon;Ryoo, Rhim;Ka, Kang-Hyeon
    • The Korean Journal of Mycology
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    • 제46권3호
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    • pp.325-331
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    • 2018
  • We aimed to increase the utility of Broussonetia kazinoki (paper mulberry) by using its woody parts as a substrate for Lentinula edodes cultivation. Using different mixing ratios of paper mulberry and oak tree sawdust, five types of column-type media were prepared (1.2 kg each). Two L. edodes strains (NIFoS 2462 and NIFoS 2778) were used in this study. In the first flush, numerous small mushrooms were harvested because the fruited mushrooms were densely packed on the small media. The highest productivity was obtained with a 3:1 mixture of paper mulberry and oak tree sawdust (Q. acutissima:Q. mongolica, 1:1). In particular, for NIFoS 2462, the proportion of paper mulberry in the medium positively correlated with productivity. The size of NIFoS 2778 was uniform in all media tested. By contrast, the mushroom weight of NIFoS 2462 decreased, but the other characteristics were not significantly affected. Collectively, these findings suggest that B. kazinoki sawdust could be used to grow shiitake mushrooms and that some oak sawdust substitution is also possible. Our results could increase the utility of discarded by-products, such as sawdust.

Lateral Root Formation and Growth of Soybean Sporouts Treated with Various Solutions (다양한 물질처리에 의한 콩나물의 세근형성 및 생장)

  • Kang, Jin-Ho;Park, Cheol-Jong;Yoon, Soo-Young;Jeon, Seung-Ho;Hong, Dong-Oh
    • Korean Journal of Medicinal Crop Science
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    • 제13권1호
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    • pp.6-10
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    • 2005
  • Lateral roots of soybean sprouts should deeply affect their quality and marketability. The study was done to compare the effects of ocher, chitosan, corn kennel, tea (Thea sinensis L.) and hard rubber tree (Eucommia ulmoides Oliver) leaf extracts on lateral root formation, growth and morphological characters of the sprouts. Seeds of three cultivars, Pungsannamulkong, Sowonkong and Junjery, were imbibed for 5 hours into their 10% solutions and cultured for 6 days. The cultured sprouts were classified into 4 categories to calculate their composition rates on the base of hypocotyl lengths;>7 cm (A), 4 to 7 cm (B), < 4 cm (C) and not germinated (D), and their morphological characters, fresh and dry weights were measured. Composition rate of A was the lowest in Junjery of the three cultivars, while that of C showed reverse result compared to A. This results was the most distinct in hard rubber tree leaf extracts (HRTLE) of the five treatments. In HRTLE treatment, lateral root formation rate were formed in almost of Sowonkong although reduced in order of Pungsannamulkong and Junjery. However, there was no significant difference between the other treatments. Lateral roots per sprout were the lowest in HRTLE treatment of the 5 treatments. In all treatments except the chitosan treatment, the roots were most formed in Sowonkong but least in Junjery. Sprout length adding hypocotyl and root was the shortest in Junjery compared to the other two cultivars. and was the longest in tea leaf extract treatment but the shortest in HRTLE treatment. The result in total fresh weight of sprouts was similar to that of the sprout length.