• 제목/요약/키워드: Natural variability

검색결과 289건 처리시간 0.027초

선택적 부족분 공급방식에 따른 댐 하류하천의 유황 변화 분석 (Flow duration change in downstream of reservoir by selective deficit supply method)

  • 최영제;박문형
    • 한국수자원학회논문집
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    • 제55권12호
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    • pp.1021-1030
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    • 2022
  • 최근 우리나라의 물 관련 정책은 수량-수질-수생태 통합관리 방향으로 진행되고 있으며, 특히 하천의 자연성 회복이 주요한 이슈가 되고 있다. 이수기 댐 운영에 있어서는 가뭄, 물 수요 증가 등으로 용수공급 효과를 극대화시킬 수 있는 부족분 공급방식을 적용하고자하는 시도들이 이어지고 있다. 댐 운영에 부족분 공급방식을 적용하면 댐의 용수공급능력을 극대화 시킬 수는 있지만 하류 하천의 유량이 일정하게 유지된다는 특징이 있다. 자연하천은 오랜 시간동안 형성된 하나의 생태계로 유량의 변동성에 큰 영향을 받는다. 결국 부족분 공급방식을 적용한 댐 운영은 수량 관리에서는 효과적이지만 하천의 자연성 회복 및 수생태 측면에서는 부정적 영향을 미칠 수있다. 본 연구에서는 저수지 모의를 통해 보장량 공급방식, 부족분 공급방식, 선택적 부족분 공급방식 등의 댐 운영이 하류 하천 유황에 미치는 영향을 분석하고, 각 운영방식의 적용 효과에 대해 분석하고자 하였다. 그 결과 보장량 공급방식을 적용하면 하천의 유량 변동성은 크게 유지할 수 있으나 댐의 용수공급능력은 크지 않은 것으로 나타났다. 부족분 공급방식을 활용하면 용수공급능력을 증대시킬 수는 있으나 하류의 평수량과 갈수량의 차이가 매우 작아 유량의 변동성 측면에서는 매우 취약한 것으로 확인되었다. 선택적 부족분 공급방식을 적용할 경우 기간신뢰도를 95% 이상으로 유지하며, 하류 하천의 유황은 보장량 공급방식을 적용할 때와 유사하게 유지할 수 있는 것으로 분석되었다.

Sensitivity Analysis of High and Low Flow Metrics to Climate Variations

  • Kim, Jong-Suk;Jang, Ho-won;Hong, Hyun-Pyo;Lee, Joo-Heon
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2018년도 학술발표회
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    • pp.355-355
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    • 2018
  • Natural hydrology systems, including high flow and low flow events, are important for aquatic ecosystem health and are essential for controlling the structure and function of ecological processes in river ecosystems. Ecosystem responses to flow changes have been studied in a variety of ways, but little attention has been given to how episodic typhoons and atmospheric circulation patterns can change these hydrologic regime-ecological response relationships. In this diagnostic study, we use an empirical approach to investigate the salient features of interactions between atmospheric circulation, climate, and runoff in the five major Korean river basins.

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Marine Gastrotrichs of the Genus Diplodasys (Macrodasyida: Thaumastodermatidae) from Korea

  • Lee, Ji-Min;Chang, Cheon-Young
    • Animal Systematics, Evolution and Diversity
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    • 제22권1호
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    • pp.109-115
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    • 2006
  • Two marine gastrotrich species are reported from sublittoral sand bottom of Korea: Diplodasys ankeli Wilke, 1954 and D. meloriae Todaro, Balsamo and Tongiorgi, 1992. Both species are redescribed in detail, with the discussion on the intraspecific variability between Korean specimens and the original description or among Korean specimens. The genus Diplodasys is newly recorded from Korea as well as the Northwest Pacific.

Analysis of Genetic Variation in Botrytis cinerea Isolates Using Random Amplified Polymorphic DNA Markers

  • Choi, In-Sil;Kim, Dae-Hyuk;Lee, Chang-Won;Kim, Jae-Won;Chung, Young-Ryun
    • Journal of Microbiology and Biotechnology
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    • 제8권5호
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    • pp.490-496
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    • 1998
  • Random amplified polymorphic DNA (RAPD) markers were used to survey genetic variability among 34 Botrytis cinerea isolates from nine different host plants in Korea. For RAPD analysis, 115 arbitrary decamer primers were initially screened for polymorphic major DNA bands with 11 representative B. cinerea isolates. Eleven primers that initially detected polymorphisms were tested a second time with additional 23 isolates of B. cinerea as well as one isolate of Botrytis squamosa as an outgroup. The RAPD analyses revealed that all isolates except one showed different molecular phenotypes. Dendrograms obtained from dissimilarity matrices using the unweighted paired group method of arithmetic means (UPGMA) showed the 36.4% to 90.0% similarity among all B. cinerea isolates. The B. squamosa isolate showed the least similarity to all B. cinerea isolates. The cluster analyses indicated no correlation among all the characteristics examined including molecular phenotypes, host and geographic origins, year of isolation, or pathogenicity. The RAPD data suggest that a high level of genetic variation exists among Korean populations of B. cinerea and it seems to be caused by heterokaryosis among preexisting molecular phenotypes.

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One new species and three records of cytheroid ostracods (Crustacea, Ostracoda) from Korea

  • Karanovic, Ivana;Yoo, Hyunsu;Tanaka, Hayato;Tsukagoshi, Akira
    • Journal of Species Research
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    • 제6권spc호
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    • pp.38-50
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    • 2017
  • This study describes a new species of cytheroid ostracod, Paradoxostoma koreana sp. nov., collected in Korea. In addition, three other cytheroid ostracods, P. setoense Schornikov, 1975, Loxoconcha pulchra Ishizaki, 1968, and Ishizakiella miurensis (Hanai, 1957), are reported with brief descriptions and images. Paradoxostoma setoense and L. pulchra were previously only known from Japan, while I. miurensis was previously reported from Korea. Here, we describe variability in hemipenis morphology observed in the Korean population. The new species is closely related to several East Asian species, but its sister species is P. rhomboideum Okubo, 1977. The primary difference between the new species and P. rhomboideum is morphology of the distal projections of the hemipenis, but minor differences exist in the details of the cheatotaxy of other appendages. This report also provides a list of all East Asian Paradoxostomatidae.

Two New Tetranchyroderma Gastrotrichs(Macrodasyida, Thaumastodermatidae) from South Korea

  • Chang, Cheon-Young;Lee, Ji-Min
    • Animal cells and systems
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    • 제5권3호
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    • pp.187-194
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    • 2001
  • Two new gastrotrich species belonging to genus Tetranchyroderma are described on the basis of the specimens from intertidal or sublittoral sand bottoms of South Korea. Tetranchyroderma heterotentaculatum, n. sp. is clearly differentiated from its congeners by the character combination: the cuticular armature with pentancres, modified rod-like cephalic tentacles, and three pairs of dorsolateral adhesive tubes. Tetranchyroderma hoonsooi, n. sp. possesses tetrancres, paired lateral cephalic tentacles, and ventro-lateral adhesive tubes along whole lateral margin, while lacks dorsal adhesive tubes. Affinities with its congeners and variability within the species are discussed, with brief notes on morphological discrepancies between adults and juveniles.

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Effects of sleep-inducing juice on sleep quality and heart rate variability in adults with disturbed sleep

  • Kim, Choun-sub;Kim, Maengkyu;Kim, Min-ju;Jung, Hyeyoung
    • Nutrition Research and Practice
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    • 제14권6호
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    • pp.606-620
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    • 2020
  • BACKGROUND/OBJECTIVES: Although some juices affect subjective sleep quality, there is a lack of information on the effect of a specific juice on objective sleep quality and heart rate variability (HRV) during sleep; thus the present study investigated whether a blended juice made from natural extracts influenced sleep quality and HRV during sleep in adults with disturbed sleep. SUBJECTS/METHODS: A randomized, crossover study was conducted on twenty-five adults (15/10, female/male) complaining of difficulty initiating or maintaining nighttime sleep (Pittsburgh sleep quality index [PSQI] ≥ 5). During feeding sessions (FS), subjects received sleep-inducing juice made of natural ingredients (250 mL/trial) twice a day for 8 weeks or non-FS (N-FS) for 8 weeks while maintaining normal activities. Sleep quality and parameters were recorded via wearable actigraph for 7 consecutive days, and PSQI scores were assessed before and after the intervention. HRV was also monitored at rest and during sleep. RESULTS: After receiving the sleep-inducing juice intervention (FS), PSQI scores were significantly decreased (P < 0.001) and correlated with a significant decline in fatigue severity scale and visual analogue scale levels (P < 0.05; both). HRV indices of vagal activity were significantly improved during FS (P < 0.05), and no significant differences in N-FS were observed. Sleep efficiency and total sleep time increased significantly (P < 0.05) and sleep latency, total counts, sleep fragmentation index, and movement index, decreased significantly (P < 0.05, all 4) during FS, with no significant differences-observed during N-FS. CONCLUSIONS: This study results demonstrated that an 8-week course of sleep-inducing juice has led to improve sleep quality, suggesting an enhanced cardiac vagal tone during sleep. Thus, it could be a well-tolerated option for adults with disturbed sleep.

An Experimental Study of Comfortable Pitch and Loudness with Target Matching: Effects on Electroglottographic and Acoustic Measures

  • 최성희
    • 말소리와 음성과학
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    • 제4권4호
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    • pp.139-146
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    • 2012
  • This study was designed to examine comfort levels of pitch and loudness with target matching and their effects on electroglottographic (EGG) and acoustic measures. Twelve speakers, six males and six females, were instructed to produce /a/ sustained vowel for three seconds at a comfortable pitch and loudness level without any instruction and with a target matching procedure of either a certain f0 or SPL separately with visual and auditory feedback. The range of pitch for females and males were presented by progressing up and down randomly at intervals of 5Hz from 150 Hz to 310 Hz (total 33 frequency targets) and from 85 Hz to 190 Hz (total 22 frequency targets), respectively. The loudness levels were 65, 75, 85, 95 dB (total of four intensity targets) for both males and females. Subjective estimations of comfortable levels were obtained using a 10-point equal-appearing interval rating scale following each phonation. The results showed that males and females demonstrated similar trends in loudness levels with greatest comfort at 75 dB, whereas pitch comfort ratings showed a greater variability with females having a wider range with target matching. In the comfort levels of individuals, most male and female speakers rated higher comfort at soft, rather than loud phonations. On the other hand, most male speakers perceived highest comfort levels below the comfort pitch levels they phonated under natural conditions. Higher frequency ranges, however, were perceived to be more comfortable than those of natural condition in most female speakers, although the comfortable pitch levels in spontaneous phonations were within the comfort level ranges determined by targeted phonations. When comparing acoustic (%jitter, %shimmer, SNR) and EGG measures (CQ%) between spontaneous comfortable phonations and targeted phonations produced by the same subject at similar f0 and intensity, no significant differences were observed (p>0.05). Thus, target matching procedures may be considered a compatible and alternative method to reduce the variability of comfortable pitch and loudness levels by eliciting consistent comfortable phonations.

Water Quality Characteristics and Fish Community of the Gucheon Reservoir and Yeoncho Reservoir in Geoge Island

  • Han, Jeong-Ho;Paek, Woon-Kee;An, Kwang-Guk
    • 한국환경생태학회지
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    • 제29권1호
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    • pp.29-45
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    • 2015
  • Water chemistry and fish community, based on fish compositions and ecological characteristics(trophic/tolerance guilds and condition factor), were compared in Gucheon Reservoir($G_cR$) and Yeoncho Reservoir($Y_cR$). Chemical parameters of water quality such as BOD, COD, nutrient(N, P) and suspended solids indicated that water quality was better in the $Y_cR$ than $G_cR$, and the temporal variability in seasonal and interannual patterns were greater in the $Y_cR$. The greater variability was mainly attributed to intense dilutions of reservoir water by Asian monsoon rain during July-August. Fish guild analysis indicated that species diversity was higher in the $G_cR$ than the $Y_cR$, and that the proportion of tolerant and omnivore species were greater in the $Y_cR$. Regression analysis of body weight-total length showed that the regression coefficient(b value) was lower in the $G_cR$(2.15 ~ 2.40) than the $Y_cR$(2.59 ~ 3.14). Condition factor(K) of fish against the total length showed negative slope of Zacco temminckii, Carassius auratus, Pseudorasbora parva and Rhinogobius brunneus population in the $G_cR$, and a positive slope of Carassius auratus and Rhinogobius brunneus population in $Y_cR$. Overall, our data suggest that the growth of the fish populations, based on the length-weight relations and condition factor, reflected the trophic regime of nutrients and organic matter.

경상남도 웰니스관광의 염증면역지표, 자율신경균형, 정서, 피로, 스트레스, 삶의 질 및 수면의 질 개선에 미치는 단기효과 (Short-term Effect of Gyeongsangnam-do Wellness Tourism on Inflammatory and Immune System Markers, Emotion, Fatigue, Stress, Quality of Life, and Quality of Sleep)

  • 이새롬;이예리;이상엽
    • 대한통합의학회지
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    • 제9권3호
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    • pp.19-35
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    • 2021
  • Purpose : Recently, there has been a growing social interest in aging well. Consequently, wellness tourism has begun to attract attention. However, no studies on whether wellness tourism has any objective health benefits have been carried out yet. In this study, we assess the health benefits as well as the degree of improvement in health of a wellness tourism program. Methods : The study involved 30 adults over the age of 19 who live in the Gyeongsangnam-do region. Participants were evaluated on health indicator before and after participating in wellness tourism program. Participants took heart rate variability (HRV) test, and LFT, RFT, CBC, FBS HbA1C, and CRP test were conducted before and after the tour. Additionally, a survey was conducted before and after the program, and participant satisfaction was evaluated. Statistical differences in the tests conducted before and after the program were analyzed using a design t-test, a Wilcoxon signed-rank test, and McNemar's test. Results : The study showed that participants were very satisfied with and had significant health improvements after the wellness tourism program. The program was also found to be beneficial in improving participants' emotions as follows: BDI (p<.001), fatigue recovery (p=.006), stress relief (p=.003), improved quality of life (p<.05), and improved sleep quality (p<.001). Conclusion : Wellness tourism programs are specifically beneficial for improving participants' emotions (depression, anxiety), fatigue, stress levels, quality of life, and sleep. Therefore, they are beneficial to the overall health. Further research in the future by way of a follow-up study on the long-term effects on health after short-term interventions will provide more validation data.