• Title/Summary/Keyword: $q^2$-index

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A Study on the Community Structure of Vegetation Landscape in Naejangsan National(I) (내장산국립공원 식물경관의 군집구조에 관한 연구(I))

  • 이규완;심경구
    • Journal of the Korean Institute of Landscape Architecture
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    • v.21 no.2
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    • pp.50-67
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    • 1993
  • This study analyzed the distribution and structure of the vegetation landscape in Naejangsan National Park. The plant distribution was investigated using a field survey. There were 72 sites sampled using the clumpled sampling method. The data derived from the investigation was analyzed using the quantitative analysis of Bray-Curtis method. The analysis was performed by the classification of TWINSPAN. The ordination of DCA and RA was used for the species composition and successional trends. The results are as follows; 1. Quercus. serrata-Q. variabilis community as 21.76(16.49$\textrm{km}^2$), was the largest community in the actual vegetation of the Naejangsan National Park. The degree of green naturality index 8 area covered 64.8% of the study area and the index 6 area did 16%. 2. Classified by the ordination of DCA and environmental variables, such as the plant community was divided into seven groups according to the altitude and forming groups; Chamaecy Paris. pisifera-P.densiflora community, P.densiflora community, Q.variailis community, T.nuciofera-A.palmatum community. 3. Ther species diversity and evenness indices of C.pisifera-P.densiflora community, P.densiflora community appeared low but C.laxiflora communitywhich was the most stable community in the study area. 4. The similarity indices between Q.variabilis community and Q.serrata-Q.variabilis community were calculated 58.84%, but those between other communities were comparatively low level. 5. The successional trends of DBH class seem to be from C. pisifera-P.densiflora community, P.densiflora community to Quercus species community and from Q.variabilis community, Q.serrata-Q.variabilis community to Carpinus species community. 6. Results suggested that the successional trends in Naejangsan National Park; P.densiflora community\longrightarrowQ.variablilis community, Q.serrata-Q.variabilis community\longrightarrowC.laxiflora community in sequence.

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Estimation of Potential Natural Vegetation using the Estimate to Probability Distribution of Vegetation in Bukhansan National Park (식생 분포 확률 추정을 통한 북한산 국립공원의 잠재자연식생 추정)

  • Shin, Jin-Ho;Yeon, Myung-Hun;Yang, Keum-Chul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.3
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    • pp.41-53
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    • 2013
  • The study for the estimation potential natural vegetation was estimated the occurrence probability distribution using geographic information system(GIS) in Bukhansan National Park. Correlation and factor analysis were analyzed to estimate probability distribution. Coefficients were calculated by logistic regression analysis. Correlation coefficients were significantly at the 0.01 level. Commonality of elevation, annual mean temperature, warmth index and potential evapotranspiration were high value, but topographic index was low value. Communities of over the 0.3 points distribution probability, Quercus mogolica communities were the largest area, 76,940,900 $m^2$, Pinus densiflora communities area was 860,800 $m^2$, Quercus acutissima communities area was 500,100 $m^2$ and Quercus variabilis communities area was 1,000 $m^2$, but Q. aliena, Q. serrata, Carpinus laxiflora and Zelcova serrata communities was not appeared. Therefore, potential national vegetation of Bukhansan national park was likely to be Q. mongolica community, P. densiflora community, Q. acutissima community and Q. variabilis community.

The Basic Study for Developing Plant Ecological Indices of Sacheon-si, Gyeongsangnam-do (경상남도 사천시의 식물생태지수 개발을 위한 기초연구)

  • Oh, Hyun-Kyung;You, Ju-Han
    • Journal of Environmental Impact Assessment
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    • v.21 no.4
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    • pp.509-523
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    • 2012
  • This basic study is to present the methods and raw data for carrying out to objectively assess an ecosystem by developing the plant ecological indices. The results are as follows. The plant ecological indices were 7 units including RI (Rare Index), EI (Endemic Index), SI (Specific Index), NI (Naturalized Index), UI (Urbanized Index), Pte-Q (Pteridophyta Index) and HI (Halophytes Index). The vascular plants in Mt. Waryong, Mt. Bongmyeong and Bito island were summarized as 471 taxa including 104 families, 294 genera, 419 species, 3 subspecies, 41 varieties and 8 forms. We surveyed 5 taxa of rare plants, 7 taxa of endemic plants, 38 taxa of specific plants by floristic region, 40 taxa of naturalized plants, 1 taxa of invasive alien plant, 19 taxa of pteridophyta and 14 taxa of halophytes. Bito island had the highest RI was 1.2%. Mt. Bongmyeong was 1.4% higher than other sites. If the SI of 2.9% was the highest in Bito island. Bito island was the highest NI, and the UI was the hightest in Mt. Waryong. Mt. Bongmyeong was the lowest NI and UI. In Mt. Waryong and Bito island, the highest DI was 9.1%. The Pte-Q of Mt. Waryong was 1.3 higher than the other sites. Bito island, the highest HI was 8.1%. Overall, 1.5% of RI, 1.9% of EI, 2.3% of SI, 8.5% of NI, 14.3% of UI, 9.1% of DI, 1.0 of Pte-Q and 3.0% were analyzed with HI.

Dependence of Q Factors on Core-cladding Index Contrast in Ring Resonators

  • Kim, Younghoon;Kim, Kyoungyoum;Moon, Hee-Jong;Hyun, Kyung-Sook
    • Current Optics and Photonics
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    • v.5 no.6
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    • pp.730-737
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    • 2021
  • Transmission spectra are measured from waveguide-coupled ring resonators fabricated with SiNx on SiO2. By using ring resonators with various radii and several index contrasts, the behavior of the quality factors is investigated. As the index contrast decreases, the dominant loss is from scattering for a large resonator, while that changes from scattering loss to bending loss for a small resonator. We verify that the quality factor can be drastically improved by reducing the index contrast in large ring resonators.

High Frequency Oscillations and Low Frequency Instability in Hybrid Rocket Combustion (하이브리드 로켓 연소실험에서의 고주파수 진동과 저주파수 연소불안정)

  • Chae, Heesang;Lee, Changjin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.12
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    • pp.1021-1027
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    • 2018
  • Experimental studies have been conducted to verify that the positive coupling between pressure oscillation (p') and combustion oscillation (q') of high frequency range is a prerequisite for the initiation of low frequency instability in hybrid rocket combustion. The post-chamber length and combustion equivalence ratio were selected as critical parameters to control the phase difference between p' and q', and p' amplitude in relation to the suppression of LFI. In the results, even if the post-chamber length increases, the phase difference between p' and q' maintains below pi/2, which is a necessary condition for the LFI development, but the amplification of RI (Rayleigh index) was substantially decreased leading to a stable combustion. In addition, results confirmed that combustion stability is achieved by changing the momentary equivalence ratio and/or by suppressing the positive coupling status of p' and q'. Thus, the periodic amplification of RI was identified as the middle path of the mechanism of occurrence of LFI.

The Line n-sigraph of a Symmetric n-sigraph-V

  • Reddy, P. Siva Kota;Nagaraja, K.M.;Geetha, M.C.
    • Kyungpook Mathematical Journal
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    • v.54 no.1
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    • pp.95-101
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    • 2014
  • An n-tuple ($a_1,a_2,{\ldots},a_n$) is symmetric, if $a_k$ = $a_{n-k+1}$, $1{\leq}k{\leq}n$. Let $H_n$ = {$(a_1,a_2,{\ldots},a_n)$ ; $a_k$ ${\in}$ {+,-}, $a_k$ = $a_{n-k+1}$, $1{\leq}k{\leq}n$} be the set of all symmetric n-tuples. A symmetric n-sigraph (symmetric n-marked graph) is an ordered pair $S_n$ = (G,${\sigma}$) ($S_n$ = (G,${\mu}$)), where G = (V,E) is a graph called the underlying graph of $S_n$ and ${\sigma}$:E ${\rightarrow}H_n({\mu}:V{\rightarrow}H_n)$ is a function. The restricted super line graph of index r of a graph G, denoted by $\mathcal{R}\mathcal{L}_r$(G). The vertices of $\mathcal{R}\mathcal{L}_r$(G) are the r-subsets of E(G) and two vertices P = ${p_1,p_2,{\ldots},p_r}$ and Q = ${q_1,q_2,{\ldots},q_r}$ are adjacent if there exists exactly one pair of edges, say $p_i$ and $q_j$, where $1{\leq}i$, $j{\leq}r$, that are adjacent edges in G. Analogously, one can define the restricted super line symmetric n-sigraph of index r of a symmetric n-sigraph $S_n$ = (G,${\sigma}$) as a symmetric n-sigraph $\mathcal{R}\mathcal{L}_r$($S_n$) = ($\mathcal{R}\mathcal{L}_r(G)$, ${\sigma}$'), where $\mathcal{R}\mathcal{L}_r(G)$ is the underlying graph of $\mathcal{R}\mathcal{L}_r(S_n)$, where for any edge PQ in $\mathcal{R}\mathcal{L}_r(S_n)$, ${\sigma}^{\prime}(PQ)$=${\sigma}(P){\sigma}(Q)$. It is shown that for any symmetric n-sigraph $S_n$, its $\mathcal{R}\mathcal{L}_r(S_n)$ is i-balanced and we offer a structural characterization of super line symmetric n-sigraphs of index r. Further, we characterize symmetric n-sigraphs $S_n$ for which $\mathcal{R}\mathcal{L}_r(S_n)$~$\mathcal{L}_r(S_n)$ and $$\mathcal{R}\mathcal{L}_r(S_n){\sim_=}\mathcal{L}_r(S_n)$$, where ~ and $$\sim_=$$ denotes switching equivalence and isomorphism and $\mathcal{R}\mathcal{L}_r(S_n)$ and $\mathcal{L}_r(S_n)$ are denotes the restricted super line symmetric n-sigraph of index r and super line symmetric n-sigraph of index r of $S_n$ respectively.

Physical Habitat Modeling in Dalcheon Stream Using Fuzzy Logic (퍼지논리를 이용한 달천의 물리서식처 모의)

  • Jung, Sang-Hwa;Jang, Ji-Yeon;Choi, Sung-Uk
    • Journal of Korea Water Resources Association
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    • v.45 no.2
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    • pp.229-242
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    • 2012
  • This study presents a physical habitat modeling of adult Zacco platypus in a reach of the Dalcheon Stream located downstream of the Goesaan Dam. CASiMiR model is used to estimate habitat suitability index based on the fuzzy logic. Results are compared with those from River2D model, which uses habitat preference curve for habitat suitability index. Hydraulic data simulated by River2D are used as input data for CASiMiR model after verification against field measurements. The result shows that the habitat suitability of the adult Zacco platypus is maximum around the riffle area located upstream of the bend. CASiMiR and River2D estimate the maximum weighted usable areas at the discharge rates of 7.23 $m^3/s$ and 9.0 $m^3/s$, respectively. Overall comparison of the two models employed in this study indicates that CASiMiR model overestimates the weighted usable area by 0.3~25.3% compared with River2D model in condition of drought flow (Q355), low flow (Q275), normal flow (Q185), and average-wet flow (Q95).

FRENET EQUATIONS OF NULL CURVES

  • Jin, Dae-Ho
    • The Pure and Applied Mathematics
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    • v.10 no.2
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    • pp.71-102
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    • 2003
  • The purpose of this paper is to study the geometry of null curves in a 6-dimensional semi-Riemannian manifold $M_q$ of index q, since the general n-dimensional cases are too complicated. We show that it is possible to construct three types of Frenet equations of null curves in $M_q$, supported by one example. We find each types of Frenet equations invariant under any causal change. And we discuss some properties of null curves in $M_q$.

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Validation of Quality of Life Index-Cancer among Korean Patients with Cancer (Quality of Life Index-Caner의 구성타당도 검증 -국내 암환자를 대상으로-)

  • 소향숙;이원희;이은현;정복례;허혜경;강은실
    • Journal of Korean Academy of Nursing
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    • v.34 no.5
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    • pp.693-701
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    • 2004
  • Purpose: The purpose of this study was to validate Quality of Life Index-Cancer (Q.L.I.-C) developed by Ferrans (1990) among Korean cancer patients. Method: This study design was exploratory factor analysis methodology. Q.L.I.-C was translated into Korean and reverse-translated into English. The subjects were 357 Korean patients with various cancers. Data were collected by questionnaires from May to August, 2000 and was analyzed by descriptive statistics, Principal Component Analysis for construct validity and Cronbach's alpha coefficient for reliability. Result: The range of factor loadings was .446~.841. The explained variance from the 5 extracted factors was 63.7% of the total variance. The first factor 'family' was 35.5%, and 'health & physical functioning', 'psychological', 'spiritual', and 'economic' factors were 11.5%, 6.9%, 5.6%, and 4.2% respectively. Because of cultural difference between Americans and Koreans, certain items such as sexuality, job status, and education were deleted from the extraction of factors in this study. The Cronbach's alpha coefficient was .9253 among the 28 items. Conclusion: Q.L.I.-C could be applied in measuring quality of life of Korean cancer patients. It also recommend to do further studiesfor validation of Q.L.I.-C American and Korean versions relating to cultural differences.

The Classification of Forest Communities by Cluster Analysis in Mt. Seokbyung Experimental Forest of Gangwon-Do

  • Chung, Sang-Hoon;Kim, Ji-Hong
    • Journal of Korean Society of Forest Science
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    • v.99 no.5
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    • pp.736-743
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    • 2010
  • This study examined the ecological attributes of classified forest community by cluster analysis in the mixed forest of Mt. Seokbyung Experimental Forest of Gangwon-Do. The vegetation data were collected in randomly established 51 sample plots (2.04 ha) and analysis adopted the cluster analysis, importance value index, and Shannon's diversity index. Main results were as follows; 1) the study area was classified into 4 clusters (A, B, C and D). 2) The cluster A was dominated by Pinus densiflora with an importance value of 71.6%. The most dominant species in the cluster B and cluster C were Larix leptolepis (57.1%) and Quercus mongolica (40.2%), respectively. Finally, The cluster D was dominated by P. densiflora (30.6%) and Q. mongolica (31.0%) with the mixed forest. 3) In the P. densiflora community (cluster A), distribution of DBH class showed a reverse J-shaped curve. In the L. leptolepis community (cluster B), individuals of dominant species had the bell-shaped distribution. Oak species indicated uniform distribution of DBH class (under 25 cm) in the mixed P. densiflora - Q. mongolica community (cluster D). 4) The species diversity index of the communities in descending order were: Pinus densiflora - Q. mongolica community > Larix leptolepis community > Pinus densiflora community > Quercus mongolica community.