• Title/Summary/Keyword: region of variability

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Temporal and Spatial Variability of Heating and Cooling Degree-days in South Korea, 1973-2002 (한반도 난${\cdot}$냉방도일의 시공간 분포 특성 변화에 관한 연구)

  • Choi, Youn-Geun
    • Journal of the Korean Geographical Society
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    • v.40 no.5 s.110
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    • pp.584-593
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    • 2005
  • The spatial and temporal variations of heating degree-days (HDDs) and cooling degree-days (CDDs) are closely related with the temperature field. The spatial distribution of 30-year mean HDDs shows that the higher values locates in the northern part of South Korea while the lower values locates in the southern part. The 30-year mean CDDs shows a more randomized distribution than the HDDs. The changing trends of HDDs and CDDs show a different feature: HDDs have a distinct decreasing trend while CDDs have an insignificant change. The decreasing trends of HDDs are consistent over South Korea and most of stations have experienced the statistically significant change. As significant changing areas of HDDs are much broader than those of annual mean temperature, HDDs can be more useful than annual mean temperature to detect the climate change impact on a regional level. In other words, an insignificant change on the mean temperature field can induce the significant change of thermal climatology in a region. The temporal pattern of climatic departure index (CDI) for South Korea HDDs series shows a general decreasing, but a sharp increase during recent years. The drastic decrease of HDDs induces higher CDI indicating larger variability among stations. However, the decrease of South Korea HDDs series cannot totally attribute to the global warming due to urban effects. By the early 1980s, there were no big differences of HDDs between urban and rural series, but later the differences are getting larger. This was expected to be with the intensification of urbanization in South Korea. However, still there is a decreasing trend of HDDs for rural stations.

A Study on Standardization of Measuring Time for Heart Rate Variability (심박변이도(心搏變移度)의 측정시간(測定時間) 표준화(標準化) 연구(硏究))

  • Kim, Kyu-Tae;Park, Young-Jae;Park, Young-Bae;Oh, Hwan-Sub
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.10 no.2
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    • pp.88-103
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    • 2006
  • Objectives : We performed this study to search the best time for HRV measuring and which index has the validity in a short term measuring. Methods : At first, three examiner measured electrocardiogram(ECG) of 5 people(4 male + 1 female) for 20 minutes in two times. and we devided ten regions (0-5, 5-10, 10-15, 15-20, 0-10, 0-15, 0-20, 5-15, 10-20, 5-20 minutes). After that we finded the HRV index for each regions. To evaluate the validity, we used Gage Repeatability and Reproducibility Study by MINITAB(ver. 13.20). If the '%Study Var' is under 30 and 'Number of Distinct Categories' is over 4, we could tell it has validity(repeatability and reproducibility). Results : 1) The region and HRV index has repeatability and reproducibility, was HF index in 10-15 minutes. The HF index in 15-20 minutes gained 27.41(%Study Var) and 5(Number of Distinct Categories). 2) The HF index in 10-15 minutes has the better reproducibility than repeatability. The value of measurement is under the control. There is consistency among the examiner. The distribution of measurement is not large. There is no interaction between examiner and each people. 3) The HF index in 10-15, 0-10, 0-15, 0-20, 10-20 minutes was not enough to gain the repeatability and reproducibility. But it had some meanings ; %Study Var, Number of Distinct Categories is 32.68, 4 for 10-15 minutes, 34.43, 4 for 0-10 minutes, 34.44, 4 for 0-15 minutes, 33.56, 4 for 0-20 minutes, 32.07, 4 for 10-20 minutes. Conclusions : This study shows the best index of measuring HRV is the HF index in 15-20 minutes. So, from now on we should measure the HRV for 20 minutes and extract the HF index in 15-20 minutes. It must be the standard for HRV measuring.

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A Phylogenetic Relationships of Araliaceae Based on PCR-RAPD and ITS Sequences (PCR-RAPD와 ITS 서열 분석에 의한 두릅나무과 (Araliaceae) 의 유연관계 분석)

  • 김남희;양덕춘;엄안흠
    • Korean Journal of Plant Resources
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    • v.17 no.2
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    • pp.82-93
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    • 2004
  • Phylogenetic relationships among species in Araliaceae were analyzed using PCR-RAPD and sequence of ITS region of nuclear ribosomal DNA based on samples collected in Korea. RAPD analysis showed various polymorphic bands which were able to differentiate species and genus, and specific bands showing variations among individuals within species. Cluster analysis using gel images revealed high molecular variability within species of Aralia eleta. No significant variation was found among cultivated species of Panax ginseng, but they showed high genetic differences with wild type of the species. In ITS analysis, specific sequences for each genus and species were observed and these were allowed to differentiate species and genus. Phylogenetic analysis using ITS sequences showed that Acanthopanax and Kalopanax had a close relationship, and Aralia and Panax are monophyletic, but genus Hedera is different species from other species in family Araliaceae in this study. The results showing close relationship between genera Aralia and Panax were also observed in RAPD analysis. Contrary to the results of RAPD analysis of Panax ginseng, sequence analysis of ITS showed no significant difference between wild mountain ginseng and cultivated species of P. ginseng. Also, both RAPD and ITS analysis of P. ginseng showed no significant genetic variability among cultivation sites. Results indicate that P. ginseng cultivating in Korea is monophyletic. The molecular analysis used in this study agreed on classification using morphological feature. These results suggest that molecular techniques used in this study could be useful for phylogenetic analysis of Araliaceae.

Korean Flood Vulnerability Assessment on Climate Change (기후변화에 따른 국내 홍수 취약성 평가)

  • Lee, Moon-Hwan;Jung, Il-Won;Bae, Deg-Hyo
    • Journal of Korea Water Resources Association
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    • v.44 no.8
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    • pp.653-666
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    • 2011
  • The purposes of this study are to suggest flood vulnerability assessment method on climate change with evaluation of this method over the 5 river basins and to present the uncertainty range of assessment using multi-model ensemble scenarios. In this study, the data related to past historical flood events were collected and flood vulnerability index was calculated. The vulnerability assessment were also performed under current climate system. For future climate change scenario, the 39 climate scenarios are obtained from 3 different emission scenarios and 13 GCMs provided by IPCC DDC and 312 hydrology scenarios from 3 hydrological models and 2~3 potential evapotranspiration computation methods for the climate scenarios. Finally, the spatial and temporal changes of flood vulnerability and the range of uncertainty were performed for future S1 (2010~2039), S2 (2040~2069), S3 (2070~2099) period compared to reference S0 (1971~2000) period. The results of this study shows that vulnerable region's were Han and Sumjin, Youngsan river basins under current climate system. Considering the climate scenarios, variability in Nakdong, Gum and Han river basins are large, but Sumjin river basin had little variability due to low basic-stream ability to adaptation.

An investigation of predictability among variables having an effect on problem solving skill and achievement in collaborative learning by utilizing SNS (SNS를 활용한 협력학습에서 문제해결력과 성취도에 영향을 미치는 변인들 간의 예측력 규명)

  • Hong, Yu-Na
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.5
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    • pp.221-228
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    • 2016
  • This study was intended to investigate predictability among variables having an effect on problem solving skill and achievement in collaborative learning by utilizing SNS at university. To this end, 61 first-year students majoring in early childhood education at I community university in the national capital region were surveyed. And on the basis of the collected data, a multiple regression analysis was carried out. The results of carrying out the analysis are as follows. First, it was shown that self-efficacy, peer learning and help seeking had a significant effect on problem solving skill, and explained 70 of variability in problem solving skill. Second, it was shown that peek learning, help seeking and problem solving skill significantly predicted achievement, and explained 72% of the variability in achievement. Third, problem solving skill partially mediated the relationship between self-efficacy and achievement. The above-mentioned results imply that learning motivation should be increased so that learners have self-efficacy in order to improve college students' academic achievement in collaborative learning by utilizing SNS at university, and a class environment making it possible to actively provide peer learning and help seeking should be designed and a specific scheme enabling the enhancement of the problem solving skill should be considered.

Effect of Starvation on Some Parameters in Rhynchocypris oxycephalus (Sauvage and Dabry): A Review (버들치, Rhynchocypris oxycephalus (Sauvage and Dabry) 기아시 일부형질에서의 효과: 개관)

  • Park In-Seok
    • Korean Journal of Environmental Biology
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    • v.22 no.3
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    • pp.351-368
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    • 2004
  • Following the previous experiments, a starvation experiment was conducted to determine the influence of feeding and starvation on the histological and biochemical changes, the morphormetric changes in the sectioned body and the morphometric changes in Rhynchocypris oxycephalus (Sauvage and Dabry). The influence of starvation on nutritional conditions of the histological changes of hepatocyte and intestinal epithelium as hepatosmatic index (HSI), protein, RNA and DNA concentrations of liver in R. oxycephalus was tested. Although the starved group showed higher concentrations of protein, DNA and RNA than the fed group, food deprivation resulted in a decrease in the HSI, hepatocyte nucleus size and nuclear height of the intestinal epithelium. The RNA - DNA ratio appears to be a useful index of nutritional status in R. oxycephalus and may be useful for determining if R. oxycephalus is in a period of rapid or slow growth at the time of sampling. Additionally, the data have been interpreted in detail and some biologically important relationships discussed. The effects of starvation on the morphometrical changes in sectioned body traits, condition factor, viscera index and dressing percentage were determined for evaluating nutritional conditions of R. oxycephalus. Starvation for nine weeks resulted in a decrease in most sectioned traits as well as in condition factor and viscera index (P<0.05). These findings suggest that nutritional parameters used in this study appear to be a useful index for nutritional status in this species. The data has been interpreted in detail and some important body sectioned values of interest to commercial growers discussed. A 75-day study was conducted to determine the effect of starvation on classical and truss parameters in R. oxycephalus. Truss dimensions of almost the entire head and trunk region as well as the abdomen were increased significantly through feeding or starvation (P<0.05). Truss dimensions of the caudal region generally decreased through feeding or starvation, particularly those dimensions at the hind part of the trunk. There were some significant decreases in classical dimensions of the head region during feeding, in relation to body depth characteristics in the trunk and caudal region during starvation, whereas there was only one decreasing classical dimension in the caudal region during feeding. The results of this study indicate that application of the truss network as a character set enforces classical coverage across the body form, discrimination among experimental groups thus being enhanced. Considering that the dimension of the lower part of the head and some truss and classical dimensions were least affected by feeding and starvation, these dimensions may then be useful as a taxonomical indicator to discriminate the species of Rhynchocypris sp. The value of trunk region dimensions with a large component of body depth in R. oxycephalus is most likely to be compromised by variability related to differences in feeding regimes of fish in different habitats.

The Variations of Stratospheric Ozone over the Korean Peninsula 1985~2009 (한반도 상공의 오존층 변화 1985~2009)

  • Park, Sang Seo;Kim, Jhoon;Cho, Nayeong;Lee, Yun Gon;Cho, Hi Ku
    • Atmosphere
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    • v.21 no.4
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    • pp.349-359
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    • 2011
  • The climatology in stratospheric ozone over the Korean Peninsula, presented in previous studies (e.g., Cho et al., 2003; Kim et al., 2005), is updated by using daily and monthly data from satellite and ground-based data through December 2009. In addition, long-term satellite data [Total Ozone Mapping Spectrometer (TOMS), Ozone Monitoring Instrument (OMI), 1979~2009] have been also analyzed in order to deduce the spatial distributions and temporal variations of the global total ozone. The global average of total ozone (1979~2009) is 298 DU which shows a minimum of about 244 DU in equatorial latitudes and increases poleward in both hemispheres to a maximum of about 391 DU in Okhotsk region. The recent period, from 2006 to 2009, shows reduction in total ozone by 6% relative to the values for the pre-1980s (1979~1982). The long-term trends were estimated by using a multiple linear regression model (e.g., WMO, 1999; Cho et al., 2003) including explanatory variables for the seasonal variation, Quasi-Biennial Oscillation (QBO) and solar cycle over three different time intervals: a whole interval from 1979 to 2009, the former interval from 1979 to 1992, and the later interval from 1993 to 2009 with a turnaround point of deep minimum in 1993 is related to the effect of Mt. Pinatubo eruption. The global trend shows -0.93% $decade^{-1}$ for the whole interval, whereas the former and the later interval trends amount to -2.59% $decade^{-1}$ and +0.95% $decade^{-1}$, respectively. Therefore, the long-term total ozone variations indicate that there are positive trends showing a recovery sign of the ozone layer in both North/South hemispheres since around 1993. Annual mean total ozone (1985~2009) is distributed from 298 DU for Jeju ($33.52^{\circ}N$) to 352 DU for Unggi ($42.32^{\circ}N$) in almost zonally symmetric pattern over the Korean Peninsula, with the latitudinal gradient of 6 DU $degree^{-1}$. It is apparent that seasonal variability of total ozone increases from Jeju toward Unggi. The annual mean total ozone for Seoul shows 323 DU, with the maximum of 359 DU in March and the minimum of 291 DU in October. It is found that the day to day variability in total ozone exhibits annual mean of 5.7% in increase and -5.2% in decrease. The variability as large as 38.4% in increase and 30.3% in decrease has been observed, respectively. The long-term trend analysis (e.g., WMO, 1999) of monthly total ozone data (1985~2009) merged by satellite and ground-based measurements over the Korean Peninsula shows increase of 1.27% $decade^{-1}$ to 0.80% $decade^{-1}$ from Jeju to Unggi, respectively, showing systematic decrease of the trend magnitude with latitude. This study also presents a new analysis of ozone density and trends in the vertical distribution of ozone for Seoul with data up to the end of 2009. The mean vertical distributions of ozone show that the maximum value of the ozone density is 16.5 DU $km^{-1}$ in the middle stratospheric layer between 24 km and 28 km. About 90.0% and 71.5% of total ozone are found in the troposphere and in the stratosphere between 15 and 33 km, respectively. The trend analysis reconfirms the previous results of significant positive ozone trend, of up to 5% $decade^{-1}$, in the troposphere and the lower stratosphere (0~24 km), with negative trend, of up to -5% $decade^{-1}$, in the stratosphere (24~38 km). In addition, the Umkehr data show a positive trend of about 3% $decade^{-1}$ in the upper stratosphere (38~48 km).

Morphometric variation, genetic diversity and allelic polymorphism of an underutilised species Thaumatococcus daniellii population in Southwestern Nigeria

  • Animasaun, David Adedayo;Afeez, Azeez;Adedibu, Peter Adeolu;Akande, Feyisayo Priscilla;Oyedeji, Stephen;Olorunmaiye, Kehinde Stephen
    • Journal of Plant Biotechnology
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    • v.47 no.4
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    • pp.298-308
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    • 2020
  • Genetic diversity among Thaumatococcus daniellii populations in the southwestern region of Nigeria were assessed using morphometric and molecular markers to determine the population structure and existing genetic relationship for its improvement, conservation and sustainable utilisation. Populations from five locations in each of the six states were used for the study. Morphometric data were collected on folia characters and analysed for variability. Genome DNA was isolated from the plant leaf and amplified by polymerase chain reaction with inter-simple sequence repeat markers (ISSR) to determine the allelic polymorphism, marker effectiveness and genetic relationship of the population. The results showed significant variations in petiole length and leaf dimensions of the populations within and across the states. These morphometric traits are the major parameters that delimit the populations and they correlated significantly at P≤0.05. Analysis of the electrophoregram showed that the ISSR markers are effective for the diversity study. A total of 136 loci were amplified with an average of 7.16 loci per marker, 63.2% of the loci were polymorphic. The Principal Coordinate Analysis revealed that seven factors accounted for 81.6% of the variation and the dendrogram separated the populations into two major groups at a genetic distance of 10 (about 90% similarity) with sub-groups and clusters. Most populations within the state had a high degree of similarity, nonetheless, strong genetic relationship exists among populations from different states. The close relationship between populations across the states suggests a common progenitor, which are likely separated by ecological or geographical isolation mechanisms.

Determination and Analysis of Hyper-Variable A Mating Types in Wild Strains of Lentinula edodes in Korea

  • Mi-Jeong Park;Eunjin Kim;Yeun Sug Jeong;Mi-Young Son;Yeongseon Jang;Kang-Hyeon Ka
    • Mycobiology
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    • v.51 no.1
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    • pp.26-35
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    • 2023
  • The diversity of A mating type in wild strains of Lentinula edodes was extensively analyzed to characterize and utilize them for developing new cultivars. One hundred twenty-three A mating type alleles, including 67 newly discovered alleles, were identified from 106 wild strains collected for the past four decades in Korea. Based on previous studies and current findings, a total of 130 A mating type alleles have been found, 124 of which were discovered from wild strains, indicating the hyper-variability of A mating type alleles of L. edodes. About half of the A mating type alleles in wild strains were found in more than two strains, whereas the other half of the alleles were found in only one strain. About 90% of A mating type combinations in dikaryotic wild strains showed a single occurrence. Geographically, diverse A mating type alleles were intensively located in the central region of the Korean peninsula, whereas only allele A17 was observed throughout Korea. We also found the conservation of the TCCCAC motif in addition to the previously reported motifs, including ATTGT, ACAAT, and GCGGAG, in the intergenic regions of A mating loci. Sequence comparison among some alleles indicated that accumulated mutation and recombination would contribute to the diversification of A mating type alleles in L. edodes. Our data support the rapid evolution of A mating locus in L. edodes, and would help to understand the characteristics of A mating loci of wild strains in Korea and help to utilize them for developing new cultivars.

Biological and Molecular Characterization of a Korean Isolate of Orthotospovirus chrysanthinecrocaulis (Formerly Chrysanthemum Stem Necrosis Virus) Isolated from Chrysanthemum morifolium

  • Seong Hyeon Yoon;Su Bin Lee;Eseul Baek;Ho-Jong Ju;Ju-Yeon Yoon
    • Research in Plant Disease
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    • v.29 no.3
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    • pp.286-294
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    • 2023
  • Biological and molecular characterization of a Korean isolate of Orthotospovirus chrysanthinecrocaulis (formerly known as chrysanthemum stem necrosis virus, CSNV) isolated from Chrysanthemum morifolium was determined using host range and sequence analysis in this study. Twenty-three species of indicator plants inoculated mechanically CSNV-Kr was investigated for determination of host range. CSNV-Kr induced various local and systemic symptoms in the inoculated plant species. CSNV-Kr could not infect three plant species and induced symptomless in systemic leaves in Nicotiana tabacum cultivars, though the plant samples reacted positively with the antiserum to CSNV by double-antibody sandwich-enzyme-linked immunosorbent assay. The complete genome sequence of CSNV-Kr was determined. The L RNA of CSNV-Kr consists of 8,959 nucleotides (nt) and encodes a putative RNA-dependent RNA polymerase. The M RNA of CSNV-Kr consists of 4,835 nt and encodes the movement protein (NSm) and the glycoprotein precursor (Gn/Gc protein). The S RNA of CNSV-Kr consists of 2,836 nt and encodes NSs protein and N protein. The Gn/Gc and N sequence of CSNV-Kr were compared with those of previously published CSNV isolates originating from different countries at nucleotide and amino acid levels. The Gn/GC sequence of CSNV-Kr shared 98.8-99.5% identity with CSNV isolated from other countries and the N sequence of CSNV-Kr shared 98.8-99.6% identity. No particular region of variability could be found in either grouping of viruses. All of the CSNV isolates did not show any relationship according to geographical origins and isolation hosts, suggesting no distinct segregation of the CSNV isolates.