• Title/Summary/Keyword: dominant period

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Effects of Thermal Effluents from Wolseong Nuclear Power Plant on Macroalgal Composition and Community Structure (월성원자력발전소 온배수가 해조류 종조성 및 군집구조에 미치는 영향)

  • Choi, Han-Gil
    • ALGAE
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    • v.23 no.2
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    • pp.151-162
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    • 2008
  • Marine algal flora and community structure were seasonally examined at three sites in the vicinity of the Wolseong nuclear power plant in Korea from February to November 2006. A total of 126 seaweeds including 25 green, 31 brown, 70 red algae, and 1 marine plant were identified. The greatest number of species occurred at Jeonchonri (101 species) followed by intake (88 species) and discharge (29 species) during the study period. Of 126 seaweeds, 76 annuals and 13 warm tolerance species were recorded. Dominant species based on important value (IV > 10) were Ulva pertusa and Enteromorpha linza at intake, U. pertusa and Padina arborescens at discharge, and Sargassum horneri and Corallina pilulifera at Jeonchonri shore. Annual average biomass exhibited a wide range of variations, from 40.67g m-2 in dry weight at discharge to 133.69g m-2 at Jeonchonri. Among six functional groups, dominant group was coarsely-branched form at intake and Jeonchonri, but it was different at discharge site as filamentous form. Seaweed community structures of discharge site were distinguishable in decreasing species richness, biomass, species diversity index (H’), richness index (R), and evenness index (J’). Also, the ratios of green algae, warm tolerance species, annual algae, filamentous form and dominance index (DI) remarkably increased. Such phenomenons of discharge site are usually found under environmentally stressful conditions such as high disturbance. Thus, I can conclude that the heated effluents of nuclear power plant act as environmental stress influencing seaweed community structures and it can be detected with various community indices.

Development of Electrogastrography System (위전도 계측시스템의 개발)

  • Han, W.T.;Kim, I.Y.;Kim, W.K.;Park, K.W.;Kim, Hui-Chan;Son, J.I.;Rhee, P.L.;Rhee, J.C.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.403-406
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    • 1997
  • Electrogastrogaphy(EGG) is the technique by which gastric myoelectrical activity is recorded noninvasively, from electrodes on the abdominal skin. Despite many attempts made over the decades, the clinical application of the EGG signal has not improved to the identification of waveform characteristics using comparison of EGG signal to be detected other EGG system. Cutaneous measurements of EGG are yet to be standardized in methods of detection and analysis. This may be responsible in part for some of the variability in the results. Thus, we develope EGG system composed of amplifiers, analysis methods, patient database or standardization. we introduce configurations of EGG system and their functions. Several important EGG parameters are introduced, including the dominant frequency and power of the EGG, the relative, period EGG-dominant frequency and power, the instability coefficient of EGG-dominant frequency and power, standard deviation, the percentage of running spectrum activity of gastric slow waves.

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Community Structure of Aquatic Insects in Miryang-Dam Water System (밀양댐 수계의 수서곤충 군집에 대하여)

  • Park, Yeon-Kyu;Park, Hyean-Cheal
    • Journal of Wetlands Research
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    • v.2 no.2
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    • pp.133-146
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    • 2000
  • An ecological survey was performed in Miryang dam water system during the period of June 5~6, 2000. The fauna collected from 7 sites consisted of total 67 species, 49 genus, 25 families, in 7 orders of aquatic insects. These included 29 species of Ephemeroptera, 22 species of Trichoptera, 7 species of plecoptera, 6 species of Diptera, 1 species of Megaloptera, Odonata and Coleoptera repectively. The relative abundance of Ephemeroptera, Trichoptera, Plecoptera, Diptera, and Coleoptera was 71 %, 11.2%, 5.1%. 11.9% and 0.6% respectively. The primary dominant species of tatal level was Epeorus aesculus, and second dominant species was Epeorus latifolium. The primary dominant species were Heptagenia kihada at site 1, Ecdyonurus dracon at site 2,3,4 and Epeorus aesculus at site 5, Epeorus latifolium at site 6,7. Dominance indices were ranged from 0.30 to 0.55, and species diversity indices from 3.11 to 4.25(mean=3.71). Saprobic system based on species diversity indicated that whole sites were oligosaprobic.

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Thermal Discharge Effects on the Species Composition and Community Structure of Macrobenthos in Rocky Intertidal Zone Around the Taean Thermoelectric Power Plant, Korea (태안화력발전소 주변 암반조간대에 서식하는 대형저서동물의 종조성 및 군집구조에 미치는 온배수의 영향)

  • Jung, Yun-Hwan;Kim, Hyung June;Park, Heung-Sik
    • Ocean and Polar Research
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    • v.40 no.2
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    • pp.59-67
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    • 2018
  • This study was conducted to understand the distribution and changes of macrobenthos on rocky intertidal areas around Taean thermoelectric power plant, Also, the purpose of this study was to produce a base-line data on the changes in water temperature due to the operation of the power plant and to understand its thermal impact on the macrobenthic community on intertidal rocky bottoms. A field survey was seasonally conducted at 3 rocky intertidal sites around the Taean thermal power plant. There was no seasonal difference in the community parameters such as number of species, mean density, biomass and species diversity during the study period. The major dominant species were Chthamalus challenger, Littorina brevicula, Crassostrea gigas. In comparison with previous study, thermal discharge in the study area did not significantly affect the distribution of dominant species. The structure of the macrobenthic community revealed that there were showed 3 different faunal groups depending on the difference in the mean density of major dominant species. The result of SIMPER analyses to determine which species were the main contributors to the differences between each community, C. challenger, Lottia spp. And Mytilus galloprovincialis, etc., revealed that there was showed a significant difference between each group. The abundance of M. galloprovincialis, showed a significant difference between faunal groups.

Early Vegetation Succession in Abandoned Field in Cheju Island (제주도 저지대 묵밭 식물군락의 2차 천이)

  • 유영한;이창석
    • The Korean Journal of Ecology
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    • v.26 no.4
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    • pp.209-214
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    • 2003
  • In order to clarify the successional trend and its characteristics of plant community in abandoned field in Cheju Island, we investigated the seral changes of vegetation height, coverage, growth form, species richness, diversity and dominance index along with the time lapse, and then compared with those of mainland researches. And in order to seek the overall trend of vegetation changes, we used cluster, TWINSPAN and PCA ordination techniques. The succession was characterized by the lower species number, lower vegetation height, longer period of herb dominant and later invasion of tree species. These results may come from that ecological traits of Cheju Island itself, and ecosystem fragmented influences that block a seed (propagule) transport. Sere of the dominant species was shown as follows: Mazus japonicus(0.5∼1 years)→Conyza sumatrensis (2 years)→Artemisia princeps var. orientalis(4 years)→Artemisia princeps var. orientalis, indigofera pseudotinctoria(5 years)→Rosa multiflora, Miscanthus sinensis, etc.(8 years)→Miscanthus sinensis(12 years)→Boehmeria nivea, Pueraria thunbergiana etc.(15 years)→Mallotus japonicus(20 years)→Litsea japonica, Machilus thunbergii (20 years<). Abandoned fields were classified into three groups according to time lapse; earlier stage(0∼1 years), middle stage(2∼8 years) and later stage(8∼20 years).

Distribution of ichthyoplankton in the West coastal waters of Korea (서해연안 해역에 분포하는 부유성 난 및 자치어의 분포특성)

  • YOUN, Byoung-Il;LEE, Seung-Jong;SOHN, Myoung-Ho;HAN, Song-hun;LEE, Hyung-been;KIM, Maeng-jin;HAN, Kyung-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.3
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    • pp.243-251
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    • 2019
  • The ichthyoplanktons were sampled by Bongo net to study the distribution of the eggs and larvae in the West coastal waters of Korea during the study period (February, May, August and October of 2017). Collected fish eggs were divided into Engraulis japonicus and unidentified species. The most dominant species, Engraulis japonicus accounted for 79.52% of the total fish egg, which was followed by unidentified species (20.48%). The total of 36 taxa in fish larvae were identified based on morphological and molecular characteristics. Fish larvae were dominant by Gobiidae species. 48.30% of the total catch in abundance, which was followed by Engraulis japonicus (31.86%). These two taxa composed 80.16% of the total collected fish larvae. The seasonal diversity index of species from the collected fish larvae in the West coastal waters in 2017 was 0.625-1.883 and the evenness index was 0.380-0.865. In addition, dominance index was 0.618-0.920 and richness was 0.573-3.189.

Study on Microbial Community Succession and Protein Hydrolysis of Donkey Meat during Refrigerated Storage Based on Illumina NOVA Sequencing Technology

  • Wei, Zixiang;Chu, Ruidong;Li, Lanjie;Zhang, Jingjing;Zhang, Huachen;Pan, Xiaohong;Dong, Yifan;Liu, Guiqin
    • Food Science of Animal Resources
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    • v.41 no.4
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    • pp.701-714
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    • 2021
  • In this study, the microbial community succession and the protein hydrolysis of donkey meat during refrigerated (4℃) storage were investigated. 16S rDNA sequencing method was used to analyze the bacteria community structure and succession in the level of genome. Meanwhile, the volatile base nitrogen (TVB-N) was measured to evaluate the degradation level of protein. After sorting out the sequencing results, 1,274,604 clean data were obtained, which were clustered into 2,064 into operational taxonomic units (OTUs), annotated to 32 phyla and 527 genus. With the prolonging of storage time, the composition of microorganism changed greatly. At the same time, the diversity and richness of microorganism decreased and then increased. During the whole storage period, Proteobacteria was the dominant phyla, and the Photobacterium, Pseudompnas, and Acinetobacter were the dominant genus. According to correlation analysis, it was found that the abundance of these dominant bacteria was significantly positively correlated with the variation of TVB-N. And Pseudomonas might play an important role in the production of TVB-N during refrigerated storage of donkey meat. The predicted metabolic pathways, based on PICRUSt analysis, indicated that amino metabolism in refrigerated donkey meat was the main metabolic pathways. This study provides insight into the process involved in refrigerated donkey meat spoilage, which provides a foundation for the development of antibacterial preservative for donkey meat.

A study on species composition and bycatch status of fishes by a three-side fyke net fisheries in Asanho Lake and Chungjuho Lake (아산호와 충주호의 삼각망에 의한 어획물 종 조성과 혼획 실태 연구)

  • Min Ah HEO;Heui Chen AN;Wan Ok LEE;Yong Beam PYEON;Seong Hun KIM
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.59 no.3
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    • pp.196-205
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    • 2023
  • This study investigated the species composition and bycatch status of fishes by fyke net between June and November 2020 in Asanho lake and Chungjuho lake. During the survey period, the catches in Asanho lake were identified as 2,931 individuals of 16 species from a total of six families and in Chungjuho lake were identified as 1,645 individuals of 14 species from a total of eight families. The dominant species in Asanho lake was Erythroculter erythropterus which accounted for 59.6% of the the total number of individuals and 40.5% of the total biomass caught. The dominant species in Chungjuho lake was Lepomis macrochirus which accounted for 48.2% of the the total number of individuals and Erythroculter erythropterus which accounted for 60.2% of the total biomass caught. The bycatch rates of non-commercial species in Asanho lake and Chungjuho lake were 77.0% and 82.6%, respectively. As a result of analyzing the frequency distribution of the total length of Carassius auratus and Siniperca scherzeri, which were the dominant species among commercial species, the bycatch rate of small individuals was 87.1%, and 42.7%, respectively.

ECG Signal Compression based on Adaptive Multi-level Code (적응적 멀티 레벨 코드 기반의 심전도 신호 압축)

  • Kim, Jungjoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.6
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    • pp.519-526
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    • 2013
  • ECG signal has the feature that is repeated in a cycle of P, Q, R, S, and T waves and is sampled at a high sampling frequency in general. By using the feature of periodic ECG signals, maximizing compression efficiency while minimizing the loss of important information for diagnosis is required. However, the periodic characteristics of such amplitude and period is not constant by measuring time and patients. Even though measured at the same time, the patient's characteristics display different periodic intervals. In this paper, an adaptive multi-level coding is provided by coding adaptively the dominant and non-dominant signal interval of the ECG signal. The proposed method can maximize the compression efficiency by using a multi-level code that applies different compression ratios considering information loss associated with the dominant signal intervals and non-dominant signal intervals. For the case of long time measurement, this method has a merit of maximizing compression ratio compared with existing compression methods that do not use the periodicity of the ECG signal and for the lossless compression coding of non-dominant signal intervals, the method has an advantage that can be stored without loss of information. The effectiveness of the ECG signal compression is proved throughout the experiment on ECG signal of MIT-BIH arrhythmia database.

Species and Abundance Variation of Fish by a Gill Net in Coastal Waters of Southern Sea, Korea, 2006 (2006 남해안 해역별 어류의 출현 종 및 양적변동)

  • Cha, Byung Yul;Kim, Dae Kwon;Seo, Seong Ho
    • Korean Journal of Ichthyology
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    • v.19 no.3
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    • pp.210-224
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    • 2007
  • Fish community study by a gill net in four coastal waters of Southern Sea, Korea were simultaneously conducted to determine seasonal variation of species composition and abundance from March to November, 2006. A total of 68 species and 577,422.9 g by four study waters were caught during the survey period. The dominant species were Platycephalus indicus, Mugil cephalus, Cynoglossus robustus and Argyrosomus argentatus of 58.2% in total catch and they occupied 63.1% in IRD (index of relative distribution). By regional community, fishes that compromised 18 species and 53,148.8 g in Tongyeong Donam were caught and the dominant species were Platycephalus indicus, Hexagrammos otakii, Liparis tessellatus, Paralichthys olivaceus. In Yeosu Gyedong, fishes of 44species and 123,926.9 g were caught and the dominant species were Platycephalus indicus, Muraenesox cinereus. In Jangheung Sumoon, fishes of 44 species and 123,926.9 g were caught and the dominant species were Mugil cephalus, Platycephalus indicus, Cynoglossus robustus, Liparis tessellatus. And in Jindo Modo, fishes of 32 species and 171,426.3 g were caught and the dominant species were Platycephalus indicus, Argyrosomus argentatus, Cynoglossus robustus. Therefore, the species composition and abundance of fish by region were very different. These results seem to be related to differences of regional environmental condition, productivity, and fish ecological habits. And the fish catch in four study waters were high from April to July, and the number of fish species and diversity index had a tendency to increased from March to November. The ranges of environmental factors caught fish were $8.3{\sim}28.5^{\circ}C$ in temperature, 26.59~34.92 in salinity and also these factors were correlated to seasonal variation of fish.