• Title/Summary/Keyword: degree distribution

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The Early Vegetational Succession of he Burned Area in Dangji-Dong (당지동의 산화적지의 초기식생천이)

  • Kim, Woen;Jeong Ho Suh;Chong Un Ri
    • The Korean Journal of Ecology
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    • v.6 no.4
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    • pp.237-242
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    • 1983
  • This is an investigation on the secondary vegetation and succession in the mixed forests destroyed by the severe crown fires on April 8, 1982. The results are summarized as follows: The floristic compositions in the investigated area are composed of 63 kinds of kinds of vascular plants. The biological type shows $ H-D_1, 4-R_5-e$, which is supposed to make a progress to the $ H-D_1-R_5-e$ type. Dominant species are Spodiopogon sibiricus (100.00)-Carex humilis var. nana (70.52)-Miscanthus sinensis var. purpurascens (61, 06)-Lespedeza maximowiczii (57.53). Lespedexa maximowiczii is prevailing as the dominant species in this area. The species diversity(H) and eveness index(e) show 3.00 and 0.74 respectively, so that the species are various and shows uniform distribution comparatively in these communities. Degree of succession(DS) is 479 in the investigated area, the value of which is comparatively higher than that of Chungcheongbuk-do area at the second year afer fires. After the crown and trunk of trees were scorched by the crown fires, the pine tree (Pinus densiflora) died and the other species could be survivd after sometimes. It some that Quercus serrata. Q. dentata, Maackia amurensis, Lespedez cyrtobotrya, Platycarya strobilacea and Lindera glauca are the fire-resistant plants.

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A Characteristic on Community Structure of Benthic Macroinvertebrates of the Shinbulsan Wetland (신불산 고산습지의 저서성 대형무척추동물 군집구조의 특성)

  • Lee, Dong-Han;Hwang, Jong-Woo;Sung, Sung-Hoon;Yoon, Chun-Sik;Cheong, Seon-Woo
    • Journal of Environmental Science International
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    • v.18 no.5
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    • pp.561-567
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    • 2009
  • The distribution of benthic macroinvertebrates of Shinbulsan wetland was investigated. This study was focused on the degree of recovery of habitat by comparing the community structure of benthic macro invertebrates of zone D to that of zone A, intact habitat. The zone D was destructed due to the construction of a golf club and the survey was performed in zone A and zone D of Shinbulsan wetland. The seasonal survey was performed in April, July and September from 2006 to 2007. From the sampling, 2 phyla, 3 classes, 9 orders, 31 families, 69 species and 1155 individuals of benthic macroinvertebrates were collected. From zone A, 2 phyla, 3 classes, 9 orders, 23 families, 54 species and 678 individuals were identified. From zone D, 2 phyla, 3 classes, 9 orders, 23 families, 43 species and 477 individuals were identified. Species diversity and species richness were higher in zone A than in zone D. The recovery of zone D was inefficient as humidity of soil was not enough to live macroinvertebrates. Also, an endangered species of macroinvertebrates, Nannophya pygmaea was found during this investigation.

A Guide on the Use of Factor Analysis in the Assessment of Construct Validity (구성타당도 평가에 있어서 요인분석의 활용)

  • Kang, Hyuncheol
    • Journal of Korean Academy of Nursing
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    • v.43 no.5
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    • pp.587-594
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    • 2013
  • Purpose: The purpose of this study is to provide researchers with a simplified approach to undertaking exploratory factor analysis for the assessment of construct validity. Methods: All articles published in 2010, 2011, and 2012 in Journal of Korean Academy of Nursing were reviewed and other relevant books and articles were chosen for the review. Results: In this paper, the following were discussed: preliminary analysis process of exploratory factor analysis to examine the sample size, distribution of measured variables, correlation coefficient, and results of KMO measure and Bartlett's test of sphericity. In addition, other areas to be considered in using factor analysis are discussed, including determination of the number of factors, the choice of rotation method or extraction method of the factor structure, and the interpretation of the factor loadings and explained variance. Conclusion: Content validity is the degree to which elements of an assessment instrument are relevant to and representative of the targeted construct for a particular assessment purpose. This measurement is difficult and challenging and takes a lot of time. Factor analysis is considered one of the strongest approaches to establishing construct validity and is the most commonly used method for establishing construct validity measured by an instrument.

A QUALITY CHECK OF THE AKARI MID-INFRARED ALL-SKY DIFFUSE MAP TOWARD THE MASSIVE STAR-FORMING REGIONS NGC 6334 AND NGC 6357

  • Sano, Hidetoshi;Amatsutsu, Tomoya;Kondo, Toru;Nakamichi, Keichiro;Yamagishi, Mitsuyoshi;Ishihara, Daisuke;Oyabu, Shinki;Kaneda, Hidehiro;Tachihara, Kengo;Fukui, Yasuo
    • Publications of The Korean Astronomical Society
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    • v.32 no.1
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    • pp.21-23
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    • 2017
  • We present a comparative study of CO and polycyclic aromatic hydrocarbon (PAH) emission toward a region including the massive star-forming regions of NGC 6334 and NGC 6357. We use the NANTEN $^{12}CO(J=1-0)$ data and the AKARI $9{\mu}m$ All-Sky diffuse map in order to evaluate the calibration accuracy of the AKARI data. We confirm that the overall CO distribution shows a good spatial correspondence with the PAH emission, and their intensities exhibit a good power-law correlation with a spatial resolution down to 4' over the region of $10^{\circ}{\times}10^{\circ}$. We also reveal poorer correlation for small scale structures between the two quantities toward NGC 6357, due to strong UV radiation from local sources. Larger scatter in the correlation toward NGC 6357 indicates higher ionization degree and/or PAH excitation than that of NGC 6334.

An Analysis on Design Error Issues of BIM Conversion Design Projects through Case Studies (사례 연구를 통한 BIM 전환설계 프로젝트의 설계오류 이슈 분석)

  • Kim, Beom-Jun;Ju, Hyung-Woo;Jang, Moon-Seok;Kim, Byeoung-Ju;Chin, Sang-Yoon
    • Journal of KIBIM
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    • v.6 no.2
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    • pp.47-57
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    • 2016
  • Recently, the introduction and spread of BIM technology has been actively promoted at the domestic level and abroad. However, the BIM adoption and diffusion rate in the whole construction industry has been slower than expected, this is because they applied to construction projects in a way that does not meet the basic objective of BIM adoption. The objective of this paper is to derive a BIM adoption strategy that can provide benefits and efficiency from the design phase, by analyzing issues related to design errors identified in two real world projects based on the 2D to BIM conversion process. Types of issues, type distribution, and degree of BIM contribution to find issues were analyzed in a quantitative way, and then a BIM adoption strategy was derived. As a result, this paper identified that there obviously exists a limit in the 2D to BIM conversion process by repeating the problems that occur in the traditional 2D design process. Therefore, the authors of this paper insist that the design firms should adopt BIM-based design processes, fully, to get financial benefits as well as to improve the design quality.

Citation Discovery Tools for Conducting Adaptive Meta-analyses to Update Systematic Reviews

  • Bae, Jong-Myon;Kim, Eun Hee
    • Journal of Preventive Medicine and Public Health
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    • v.49 no.2
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    • pp.129-133
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    • 2016
  • Objectives: The systematic review (SR) is a research methodology that aims to synthesize related evidence. Updating previously conducted SRs is necessary when new evidence has been produced, but no consensus has yet emerged on the appropriate update methodology. The authors have developed a new SR update method called 'adaptive meta-analysis' (AMA) using the 'cited by', 'similar articles', and 'related articles' citation discovery tools in the PubMed and Scopus databases. This study evaluates the usefulness of these citation discovery tools for updating SRs. Methods: Lists were constructed by applying the citation discovery tools in the two databases to the articles analyzed by a published SR. The degree of overlap between the lists and distribution of excluded results were evaluated. Results: The articles ultimately selected for the SR update meta-analysis were found in the lists obtained from the 'cited by' and 'similar' tools in PubMed. Most of the selected articles appeared in both the 'cited by' lists in Scopus and PubMed. The Scopus 'related' tool did not identify the appropriate articles. Conclusions: The AMA, which involves using both citation discovery tools in PubMed, and optionally, the 'related' tool in Scopus, was found to be useful for updating an SR.

A Model to Explain Temperature Dependent Systemic Infection of Potato Plants by Potato virus Y

  • Choi, Kyung San;Toro, Francisco del;Tenllado, Francisco;Canto, Tomas;Chung, Bong Nam
    • The Plant Pathology Journal
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    • v.33 no.2
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    • pp.206-211
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    • 2017
  • The effect of temperature on the rate of systemic infection of potatoes (Solanum tuberosum L. cv. Chu-Baek) by Potato virus Y (PVY) was studied in growth chambers. Systemic infection of PVY was observed only within the temperature range of $16^{\circ}C$ to $32^{\circ}C$. Within this temperature range, the time required for a plant to become infected systemically decreased from 14 days at $20^{\circ}C$ to 5.7 days at $28^{\circ}C$. The estimated lower thermal threshold was $15.6^{\circ}C$ and the thermal constant was 65.6 degree days. A systemic infection model was constructed based on experimental data, using the infection rate (Lactin-2 model) and the infection distribution (three-parameter Weibull function) models, which accurately described the completion rate curves to systemic infection and the cumulative distributions obtained in the PVY-potato system, respectively. Therefore, this model was useful to predict the progress of systemic infections by PVY in potato plants, and to construct the epidemic models.

A Study on the VOCs Contamination of Ambient Air int Kyonggi-do Area (III) (경기도 환경대기중 휘발성유기화합물의 오염실태 조사연구 (III))

  • 김종보;김종찬;최승석;임흥빈;최양희;이수문
    • Journal of environmental and Sanitary engineering
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    • v.17 no.2
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    • pp.63-70
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    • 2002
  • We investigated the concentration degree of VOCs for ambient air in the air environment control area of Kyonggi-do in 2001. The VOCs showing higher concentration were in the ascending order of Toluene > n-Butane > 1-Butene > Benzene > n-Hexane. The concentration distribution ratio mentioned above showed almost same pattern in each city. The relative concentration ratio of Benzene, Toluene, Ethylbenzene, Xylenes which are aromatic VOCs were 1 : 6.3 : 0.6 : 1.6. It was similar to the pattern in 1999 but different from the pattern in 2000. In the aspect of seasons, the highest B.T.E.X concentration was indicated in fall and in the aspect of areas, the higher concentration showed in the ascending order of Buchon > Ansan > Kwangmyong > Shihung > Sungnam. The average concentration of target VOCs for ambient air in the air environment control area of Kyonggi-do showed lower concentration than the metropolis of Seoul but higher concentration than Kwang-ju city and Dae-gu city. The amount of total VOCs was increasing, comparing with it last year and the more increasing tendency is anticipated so that it will need to establish the proper regulative criteria.

Buckling Strength of Orthogonally Stiffened Steel Plates under Uniaxial Compression (일축압축을 받는 직교로 보강된 판의 좌굴강도)

  • Choi, Dong Ho;Chang, Dong Il;Choi, Hang Yong
    • Journal of Korean Society of Steel Construction
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    • v.10 no.4 s.37
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    • pp.731-740
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    • 1998
  • Orthogonally stiffened steel plates are used for orthotropic steel decks of long-span bridges because of high degree of flexural and torsional resistances and good load-distribution behavior. An analytic study is presented for evaluating the buckling strength of orthogonally stiffened plates subjected to uniaxial compression. By using the plate theory, the buckling stress under overall and partial buckling modes, is derived. Parametric studies are performed to show the effects of the stiffness and the number of transverse and longitudinal ribs on the buckling strength. The results show quantitatively strong influence of stiffness and spacing of longitudinal and transverse ribs.

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Chemical Characteristics of Abiotic-Stressed Tobacco Stems for the Utilization of a Non-Wooden Biomass (비목질 재료의 바이오매스화를 위한 환경 스트레스 담배줄기의 화학조성)

  • Kim, Kang-Jae;Hong, Sung-Bum;Eom, Tae-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.1
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    • pp.53-60
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    • 2016
  • Abiotic-stressed tobacco stems as a non-wooden biomass were analyzed for their chemical characteristics. Light-stressed tobacco stems (LST) have a relatively high nitrogen concentration, much more extractive content, and a similar amount of lignin and higher contents of acid sugars than those of Non stressed tobacco (NST). It also has low cellulose crystallinity and a high degree of condensation. Guaiacyl units having a lower molecular weight distribution consist of rich lignin. Tension stressed tobacco (TST) growth differentiation under tensile stress was significantly different between normal tissue and cell walls, with the exception of the slightly higher cellulose crystallinity observed for.