• Title/Summary/Keyword: 군집 자료

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Seasonal Variation of Primary Productivity and Pigment of Phytoplankton Community Structure in the Seomjin Estuary (섬진강 하구역의 계절별 일차생산력 및 식물플랑크톤 색소 조성 변화)

  • Min, Jun-Oh;Ha, Sun-Yong;Chung, Mi-Hee;Choi, Bo-Hyung;Lee, Yeon-Jung;Youn, Seok-Hyun;Yoon, Won-Duk;Lee, Jae-Seong;Shin, Kyung-Hoon
    • Korean Journal of Ecology and Environment
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    • v.45 no.2
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    • pp.139-149
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    • 2012
  • Four in situ incubation experiments were conducted in May, August and November 2009, as well as February 2010 to determine the seasonal primary productivity and the community structure of phytoplankton at the Seomjin estuary. The primary production of phytoplankton ranged from 9 to 3560 mgC $m^{-2}\;d^{-1}$. Primary productivity was the highest in the summer season (August), which was influenced by improved optical and temperature conditions of the water, as well as the supply of nutrients derived from its surrounding watershed. Particularly, the upper station (SJ-1, SJ-2) of Seom-jin estuary showed a higher productivity, as a result of inflow of input nutrients originated from the terrestrial source. The fucoxanthin, as an index pigment of diatoms showed the highest concentration (0.74~9.51 ${\mu}g\;L^{-1}$) at all stations, occupying 30~80% to total Chl a concentrations. The phytoplankton species composition determination, using a microscope showed similar results to the pigment analysis, which indicated diatom Skeletonema costatum, as the dominant species. The primary productivity in Seom-jin estuary indicates temporally and spatially large variation, according to different environmental conditions. Also, Skeletonema costatum has euryhaline features with relatively higher contribution.

Assessment of Ecosystem Health during the Freshwater Discharge in the Youngsan River Estuary (영산강 하구둑 담수 방류에 따른 하구 건강성 평가)

  • Lee, Dahye;Park, Gunwoo;Lee, Changhee;Shin, Yongsik
    • Korean Journal of Ecology and Environment
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    • v.50 no.1
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    • pp.46-56
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    • 2017
  • The Youngsan River estuary was physically changed by the construction of a sea embankment at near the mouth of estuary. Weirs were also constructed recently in the freshwater zone and it was reported that algal blooms occur more frequently. The freshwater introduced into saltwater zone from sluice gates of the embankment affects water quality but it has not been addressed that how the freshwater inputs influence the health of marine ecosystem. In this study, we used the data of water properties and phytoplankton communities collected at three stations for 4 days including before the freshwater discharge, during the discharge and after 1 and 2 days of discharge events. WQI(water quality index), TRIX (trophic status index) and P-IBI(phytoplankton index of biotic integrity) were used to evaluate the ecosystem health and long-term data were also utilized to determine the criteria for P-IBI. The results showed that grades of the ecosystem health assessed by the indices were low at the station near the gates and increased as downstream. However, the temporal pattern of grades was different depending on methods. Grades of WQI and TRIX decreased during the discharge and restored after the discharge whereas the grades of P-IBI decreased slightly even after the discharge. This suggests that P-IBI is more applicable to estuarine systems where experience extreme change of water properties than WQI and TRIX since P-IBI includes phytoplankton that can respond quickly to the change.

Evaluation of habitat range and physical habitat of black shinner (Pseudopungtungia nigra) from Yongdam to Daecheong Dam in Geum River (금강의 용담댐에서 대청댐까지 서식하는 감돌고기 (Pseudopungtungia nigra)의 서식범위 및 물리적 서식지 평가)

  • Hur, Jun Wook;Kim, Kyung Hoon
    • Ecology and Resilient Infrastructure
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    • v.6 no.4
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    • pp.179-190
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    • 2019
  • In this study, a fish survey was conducted to investigate the habitat status of black shinner (Pseudopungtungia nigra) designated as endangered species level from the lower part of Yongdam Dam to the upper part of Daecheong Dam. Biodiversity analysis was performed on the basis of the number of fish emerged, and biological health and physical habitat environment were quantitatively analyzed using collected P. nigra. According to the survey, the habitat range of P. nigra was found from Banguri-myeon, Buri-myeon, Geumsan-gun, downstream of Yongdam Dam. The biodiversity analysis results of all species appeared to be low in overall dominance index and relatively high in species diversity and uniformity index. In addition, P. nigra collected in this study was confirmed to have normal growth and nutritional status by the full-length-weighted relativities and condition factor. The physical habitat environment of P. nigra was 0.3 - 0.6 m in depth, 0.3 - 0.7 m/s in flow rate, and bed materials showed high frequency of occurrence in the range of cobbles (64.0 - 256.0 mm) to boulders (>256.0 mm). These results are expected to be used as data for habitat restoration and management in the future as basic data on the spatial range and preferred physical habitat environment of P. nigra in Geumgang.

Study on the Distribution Characteristics of Storm Damage Area : The Case of Gyeonggi-do (수해지 분포 특성에 관한 연구 : 경기도 사례를 중심으로)

  • Kang, Sangjun;Jung, Juchul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.5D
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    • pp.507-517
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    • 2012
  • The main purpose of this study is to address flooding resilient land use management strategy based on the distributional characteristics of storm damage areas in Gyeonggi-do. The employed methods are 1) Exploratory Spatial Data Analysis (ESDA) to understand the spatial patterns of storm damage areas occurred from 2005 to 2009, 2) Local Indicator of Spatial Association (LISA) to examine spatial autocorrelation existed in storm damage areas for the year of 2009. The results show that 1) crop land damage is very sensitive to heavy precipitation, 2) damaged buildings are found in all over the Gyeonggi areas, but relatively more damages are in the regions closed to the City of Seoul, 3) damaged roads-bridges, streams, and reaches are found in mostly rural areas, 4) building and crop land damage occurs mostly in lowlands with different spatial patterns. These findings imply that 1) it will be useful to consider the average distances and slopes of damaged building and crop lands from streams for the decision making of land use management strategy, 2) further management efforts are required in the north, east, and south regions of Gyeonggi areas to prevent roads-bridge, stream, and reach damages, 3) the present land use pattern needs to be carefully investigated by considering the damage clustered areas for the year of 2009 based on watershed and municipality boundaries.

The Recognition and Needs of Elementary School Teachers about STEAM Education (STEAM 교육에 대한 초등교사의 인식과 요구)

  • Geum, Young-Choong;Bae, Seon-A
    • 대한공업교육학회지
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    • v.37 no.2
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    • pp.57-75
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    • 2012
  • The purpose of this study was to survey and analyze the recognition and needs of elementary school teachers about STEAM education. Mail and E-mail surveys were conducted for 533 elementary school teachers for the purpose of the study. The following were found results of the study were as follow: First, although elementary school teachers understood positively the necessity of STEAM education, showed average levels of recognition on STEAM education. Second, the rate of the elementary school teachers who had experience in applying STEAM education was low. Third, elementary school teachers required to education closely related to real life, and interesting education according to the direction for STEAM education. Fourth, elementary school teachers asked for the integration centering activities related real life, followed by the integration focusing on thema related to real life, the integrating centering student's needs and interests, and the integration focusing on issues according to the appropriate integration methods for STEAM education. Fifth, elementary school teachers required creative design/problem solving ability, academic performance ability, and interpersonal relationship skills with regard to the ability to develop through STEAM education. Lastly, elementary school teachers demanded the development and distribution of STEAM education, teacher's recognition and attitudes towards STEAM education, teacher's training for STEAM education, the distribution of reference materials and etc in order to stimulate STEAM education.

Non-Outbreak Cause of Cochlodinium Bloom in the Western Coast of Jaran Bay in Summer, 2013 : On the Basis of Nutrient Data (2013년 하계 자란만 서부 연안의 Cochlodinium 적조 미발생 원인 : 영양염 자료를 중심으로)

  • Kwon, Hyeong-Kyu;Kim, Hyun-Jung;Yang, Han-Seob;Oh, Seok-Jin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.4
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    • pp.372-381
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    • 2014
  • We investigated cause of non-outbreak of Cochlodinium polykrikoides blooms in the western coast of Jaran Bay during Summer, 2013, by combining chemical field data and physiological data of C. polykrikoides, which had been already published. The predominant species were mainly diatoms, and dominant species was Cerataulina pelagica, Chaetoceros spp., Navicula spp. and Nitzschia spp.. In case of dissolved inorganic nutrients in the western coast of Jaran Bay, dissolved inorganic phosphorus (DIP) was similar to that in previous outbreak period of C. polykrikoides blooms, but dissolved inorganic nitrogen (DIN) was lower. C. polykrikoides might be disadvantageous in competition with diatom species because half-saturation constants (Ks) of C. polykrikoides for inorganic nutrients was lower than those of diatoms. Also, the western coast of Jaran Bay, where DIN concentration is relatively low, was an unfavorable environment for growth of C. polykrikoides characterized by nitrogen dependence. Therefore, C. polykrikoides which have the disadvantageous position for competition of inorganic nutrient might have been suppressed by diatom blooms under environment of low nutrient in the western coast of Jaran Bay.

중력이상을 이용한 한반도 모호면 추출에 관한 연구

  • 김정우;조진동;김원균;민경덕;황재하;이윤수;박찬홍;황종선
    • Proceedings of the KSEEG Conference
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    • 2003.04a
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    • pp.258-264
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    • 2003
  • 중력이상 및 수치고도모델을 이용하여 한반도 모호면 심도를 추출하였다 중력이상값은 인공위성고도레이더 관폭값을 주로 이용한 전지구 모델을 이용하여 데이터영역 뿐 만 아니라 주파수영역에서도 자료의 균질성을 확보하였다. 모호면 추출은 Kim et al. [2000a]에 의해 제안된 스펙트럼 대비법 및 후리에급수를 이용한 파워스펙트럼분석법을 이용하였다. 전자는 지각근형을 전제로, 지형에 의한 중력효과와 후리에어 중력이상을 파동수영역에서 대비하여 모호면의 심도를 계산하는 방법이고, 후자는 완전부우게 중력이상으로부터 푸리에변환을 이용하여 지하 밀도 변화층의 심도를 계산하는 방법이다. 이 두 모호면은 서로 0.53의 상관관계를 갖고 있으며, 이는 모호면 산출의 방법론적인 차이 및 계산상의 오차인 것으로 사료된다. 이렇게 두 가지 독립적인 방법으로 추출된 모호면을 하나로 통합하기 위한 한 방법으로, 두 모호면의 차이를 계산한 후, 이를 최소자승법을 이용, 두 모호면을 보정하였다. 결과적으로 한반도의 최종 모호면의 평균심도는 32.0km, 표준편차는 2.5km 이며, 최소, 최대 심도는 20.3, 36.6km으로 나타났다. 이 경우 지형에 의한 중력효과는 스펙트럼대비법에 의해 제거된 결과이나, 한반도의 지각이 완전한 지각판 내에 놓여 있어서 Airy-Heiskanin 지각균형설의 가정이 타당성이 있는가, 혹은 국부적인 응력장에 의해 한반도의 지각이 과연 얼마나 지지되고 있는가 하는 것에 대한 추가적인 연구가 필요하며, 이에 앞서, 일정한 밀도차를 갖는 연속적인 밀도변화층이 존재한다는 가정이 반드시 필요하다.에는 관련성을 갖고 있으며, 이는 유류 분해정도를 파악하는 지시자로써 특정 무기 오염물질을 이용할 수 있을 가능성이 있으므로 좀더 이들 관계성에 대한 연구가 진행될 필요성이 있다고 판단된다.고 과학적으로 분석할 수 있는 방법이 될 수 있을 것으로 기대된다. 의미를 되새기는 것으로 짧은 연구를 시작하겠다. 등은 활성 값이 70% 이상으로 퇴적물 독성이 상대적으로 낮았다. 이중나선 DNA 함량은 28.4 % - 49%로 대조군에 비해서 감소가 크다. 대부분의 정점이 대조군의 30% 내외로 정점 간의 차이는 크지는 않다. 그러나 다른 측정자료와 같이 정점 22에서 18%로 최소치를 나타내고, 정점 2, 12에서 20% 내외의 값을 보인다. 종합적으로 볼 때 오염물질의 유입이 크고, 광양제철 인근 정점 들이 모두 다른 정점에 비해서 낮아서, 퇴적물 독성이 높은 정점으로 조사되었다.hiwo의 광합성 능력은 낮은 농도들에서는 대조구와 유사하였으나, 5 $\mu\textrm{g}$/l의 높은 농도에서는 초기에 매우 낮은 광합성 능력을 보이다가 시간이 경과하면서 대조군보다 더 높은 경향을 나타냈다. 이러한 결과는 식물플랑크톤이 benso[a]pyrene의 낮은 농도에서 노출될 때는 이 물질을 탄소원으로 사용할 가능성이 있음을 시사한다. 본 연구의 결과들은 연안해역에 benso[a]pyrene과 같은 지속성 유기오염물질이 유입되었을 때 내정여부에 따라 식물플랑크톤 군집내 종 천이와 일차생산력에 크게 영향을 미칠 수 있음을 시사한다.TEX>5.2개)였으며, 등급별 회수율은 각각 GI(8.5%), GII

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A Study on School Uniform Modification According to Lifestyle in High School Girls (여고생의 라이프스타일에 따른 교복변형행동 비교)

  • Wee, Eun-Hah
    • Journal of Korean Home Economics Education Association
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    • v.20 no.3
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    • pp.201-213
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    • 2008
  • This study was intended to examine the relationship between lifestyle and school uniform design modification in high school girls and provide basic data for guidance in the wearing of school uniform. The subjects of this study were 585 girls who were in the first and second grades of high schools throughout Gwangju. This study was executed using a questionnaire. The data from this study was processed using SPSS WIN 12.0(Kr). The results were as follows; This study hypothesized that the perception and attitude on school uniform modification would be significantly difference depending on lifestyles in high school girls. The significant differences appeared in a few items. So the results suggested that school uniform modification was a common that appeared in most high school girls. However it was affected by their lifestyle. specifically, a digital-dependence lifestyle group has a few different perceptions and attitudes on school uniform modification than the others. In other words, school uniform modification in high school girls who spend their most time in school is a general and universal clothing behavior by psychological factors rather than the effect of lifestyle. It is considered that rules concerning school uniform modification should allow students to express their individuality within certain limits. Teachers should instruct students to wear appropriate underwear rather than keep students under control with a fixed set of rules. If High school girls have a negative body image as a result of their exposed body, they should receive active educational guidance.

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A Comparative Study on Welfare Regimes and Welfare Attitudes : Focusing on Satisfaction and Needs of the Role of Government for Inequality Reduction (복지체제와 복지태도의 국제비교 연구 : 불평등 완화에 대한 국가역할 만족도와 요구도를 중심으로)

  • Jung, Yun-Tae
    • Korean Journal of Social Welfare Studies
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    • v.49 no.2
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    • pp.211-232
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    • 2018
  • The purpose of this study is to verify whether the types of welfare attitudes are classified according to the welfare regimes. Specifically, this study tried to confirm whether the satisfaction and needs of the role of government for inequality reduction are divided into welfare regimes. For the purpose, this study conducted a comparative analysis of 24 European countries using the 6th European Social Survey (2012) and the Eurostat data. The main results of the analysis are summarized as follows. First, there is a difference in the satisfaction and needs of the role of government for the inequality reduction among the welfare regimes. Generally, the satisfaction is high in the Nordic countries, while the needs is high in the southern and eastern European countries. Second, there is a correlation that the country where the per capita welfare expenditure level is high and the redistribution effect is strong have high level of the satisfaction. Third, the types of welfare attitudes are classified according to the welfare regimes. In particular, the Nordic countries are converging into a cluster with low needs and high satisfaction. These countries have high level of social spending and strong redistributive effects. This study suggested policy implications based on the above results.

The Effects of Parenting Attitudes on the Developmental Trajectories in School Adjustment of Adolescents in Out-of-Home Care (주양육자의 양육태도가 가정외보호 청소년의 학교적응 발달궤적에 미치는 영향)

  • An, Eunmi;Kang, HyunAh;Nho, Choong Rai;Woo, Seokjin;Chun, Jongserl;Chung, Ick Joong
    • Journal of the Korean Society of Child Welfare
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    • no.54
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    • pp.145-172
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    • 2016
  • The purpose of this study was to examine whether parenting attitudes would have an effect on the developmental trajectories of school adjustment for adolescents in out-of-home care. Additionally, we hypothesized that this model would be different between boys and girls. In this study, we analyzed three waves of data collected from 341 adolescents living in residential facilities, group homes or foster homes by using cluster sampling methods. Growth-curve longitudinal analysis was conducted, and the results indicated that levels of school adjustment had increased from the 1st through the 3rd grade of middle school. Positive parenting attitudes had a positive impact on initial school adjustment and rate of change, whereas negative parenting attitudes had a negative impact only on the initial school adjustment. Second, multi-group analysis revealed that there were group differences between boys and girls in their initial school adjustment by positive parenting attitudes. Based on these results, this study discussed further suggestions to increase school adjustments for adolescents in out-of-home care.