• Title/Summary/Keyword: 계절 변동

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Seasonal Variations in Species Composition and Abundance of Fishes Collected by an Otter Trawl in Nakdong River Estuary (낙동강 하구해역에서 저인망에 의해 어획되는 어류의 종조성 및 계절 변동)

  • 허성회;정석근
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.2
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    • pp.178-195
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    • 1999
  • The species composition and seasonal variation in abundance of fishes in the Nakdong River estuary were investigated monthly from February 1987 to January 1988. During the study period, 23,008 specimens belonging to 100 species were collected. The most abundant fish species were Repomucenus valenciennei, Pholis fangi, Leiognathus nuchalis, Trachurus japonicus, and Sardinella zunasi. These five species comprised 63.0% of total fishes and 47.8% of total biomass collected. The seasonal dominant fish species were P. fangi and R. valenciennei in spring, R. valenciennei and Cynoglossus joyneri in summer, Thryssa kammalensis and Apogon lineatus in fall, and R. valenciennei, L. nuchalis and S. zunasi in winter. The number of fish species, number of individuals collected, and species diversity indices fluctuated with the seasons. The number of species and number of individuals decreased significantly in the upper estuary. While temperature was an important factor which influenced on seasonal fluctuation of the fish community, salinity determined the spatial distribution of fishes.

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Seasonal and Interannual Variation in Species Composition of Fish Assemblages Collected by Pots in the Southern Coast of East Sea, Korea (동해 남부 연안해역 통발에서 채집된 어류 군집의 계절변동과 연간변동)

  • Park, Joo Myun;Huh, Sung-Hoi
    • Korean Journal of Ichthyology
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    • v.27 no.4
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    • pp.310-316
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    • 2015
  • The seasonal and interannual variation in the species composition and abundance of the fish assemblage were studied. Fish samples were collected seasonally over 4 year (2005 to 2008) using pots in the southern coast of East Sea. During the study period, a total of 32 fish species belonging to 24 families were collected. The dominant species were Conger myriaster, Paracentropogon rubripinnis, Liparis tanakae, Parapercis sexfasciata, Eptatretus burgeri and Clupea pallasii pallasii, which accounted for 91.9% of the total number of individuals collected. The number of species, number of individuals, biomass, and diversity fluctuated with season. The peak number of species and number of individuals occurred were in August 2008, whereas the biomass was the highest in August 2005 and diversity was in May 2008. The abundance of dominant species also showed some seasonal and interannual changes. A one-way analysis of similarity (ANOSIM) showed that the fish assemblage in 2008 was significantly different from those of 2005, 2006 and 2007, whereas there was no significant difference among seasons over 4 years.

空氣調和機 및 熱펌프에 對한 斷續運轉性能 및 季節의 表示方法

  • 민만기
    • Journal of the KSME
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    • v.22 no.5
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    • pp.341-349
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    • 1982
  • 소비자에게 이러한 마침표에 대한 사전지식을 주는 공기조화. 냉동기계의 성능평가방법에서는 쉴 사이없이 변동하는 외기온도에서의 성능과 부분부하의 단속운전(cyclic operation)에서의 성능을 밝혀주고 이를 기초로 해서 공조기 또는 열펌프의 계절성능을 밝혀주여야 될 것이다. 여기서는 그러한 새로운 계절성능의 평가절차 및 방법 중에서 계절성능을 표시하는 방법과 용어에 대해서 만 해설을 하고자 한다.

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Seasonal changes in clothing microclimate (의복기후의 계절적 변동)

  • 김양원
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2001.11a
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    • pp.164-168
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    • 2001
  • 의복착용시의 쾌적성은 의복의 보온력 조절에 의해 의복내 기후를 형성하여, 체온을 일정하게 유지하게 하는 역할을 하므로 건강과 직접적인 관련이 있다. 그러므로 건강이나 쾌적성 평가의 측면에서 의복내기후가 체계적으로 파악되어야 한다. 따라서 본 연구에서는 사무실 환경에서 의복착용시 착용실험을 실시하여 계절적인 의복내기후의 변동을 살펴보았다. 그 결과 겨울 31.8$^{\circ}C$, 48.6%, 봄 33.5$^{\circ}C$, 47.9%, 여름 32.7$^{\circ}C$, 64.6%, 가을 31.9$^{\circ}C$, 43.6%인 것으로 나타났다. 또한 계절간의 차이는 의복내온도에 있어서 가을과 겨울간에는 차이가 없었으며, 봄과 여름간에는 차이가 있었다. 의복내습도는 여름과 겨울간에는 차이가 없었으며, 다른 계절간에는 차이가 뚜렷하였다.

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Seasonal Variations in Abundance and Species Composition of Fishes in an Eelgrass Bed in Myoungjuri of Jindong Bay (진동만 명주리 잘피밭에 서식하는 어류의 종조성 및 계절변동)

  • Baeck, Gun Wook;Kwak, Seok Nam;Huh, Sung-Hoi
    • Korean Journal of Ichthyology
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    • v.17 no.1
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    • pp.8-18
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    • 2005
  • A total of 33 fish species were collected by a small beam trawl from an eelgrass bed in Myoungjuri of Jindong Bay, Korea. The dominant fish species were Hexagrammos otakii, Pholis fangi, Repomucenus valenciennei, Pseudoblennus cottoides, Pholis nebulosa, Rudarius ercodes, Syngnathus schlegeli, and Sebastes schlegeli. These 8 fish species accounted for 79.5% of the total number of individuals collected. The fishes collected in the study area were primarily small fish species or juveniles of large fish species. Seasonal variations in both species composition and abundance were large; higher numbers of fish occurred from April to June 2002, while biomass was the highest in September 2001 and 2002. Seasonal changes in fish abundance corresponded with eelgrass biomass and abundance of food organisms.

A Study on GNSS Data Pre-processing for Analyzing Geodetic Effects on Crustal Deformation due to the Earthquake (지진에 의한 측지학적 지각변동 분석을 위한 GNSS 자료 전처리 연구)

  • Sohn, Dong Hyo;Kim, Du Sik;Park, Kwan Dong
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.1
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    • pp.47-54
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    • 2015
  • In this study, we developed strategies for pre-processing GNSS data for the purpose of separating geodetic factors from crustal deformation due to the earthquakes. Before interpreting GNSS data analysis results, we removed false signals from GNSS coordinate time series. Because permanent GNSS stations are located on a large tectonic plate, GNSS position estimates should be affected by the tectonic velocity of the plate. Also, stations with surrounding trees have seasonal signals in their three-dimensional coordinate estimates. Thus, we have estimated the location of an Euler pole and angular velocities to deduce the plate tectonic velocity and verified with geological models. Also, annual amplitudes and initial phases were estimated to get rid of those false annual signals showing up in the time series. By considering the two effects, truly geodetic analysis was possible and the result was used as preliminary data for analyzing post-seismic deformation of the Korean peninsula due to the Tohoku-oki earthquake.

Seasonal Variation of Caprellids (Crustacea: Amphipoda) on Blades of Zostera marina in Kwangyang Bay, Korea (광양만 잘피엽상에 서식하는 바다대벌레류의 계절변동)

  • Yun Sung Gyu;Byun Sung Hye;Kwak Seok Nam;Huh Sung Hoi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.2
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    • pp.105-109
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    • 2002
  • Seasonal variations of species composition and density of caprellids was accomplished in eelgrass beds around Daedo Island, a south coast of Korea. Sampling was performed monthly using an epifaunal sampler at two stations from June 1996 to May 1997, Caprellids were comprised of 6 species belong to a family Caprellidae, Mean density was 402 ind./$m^2$. The numerically-dominant species were Caprella tsugarensis (216 ind./$m^2$) and C. kroeyeri (129 ind./$m^2$). High density was occurred in the early summer, and lows in autumn and winter. The density of caprellids was correlated with the biomass of the eelgrass. Predation pressure by fish was also correlated with the density of caprellids in spring.

Seasonal Variation of Airborne Chlorides in Coast by Sea Area and Region, South Korea (해역 및 지역에 따른 해안가 대기중 염분량의 계절적 변동)

  • Jung, Jahe;Lee, Jong-Suk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.5
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    • pp.611-619
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    • 2023
  • The first survey of the airborne chlorides along the nationwide coast of South Korea was conducted 18 years ago, and the area index of coastal airborne chlorides and salt attack environmental rating are being utilized in the design, construction, and maintenance of domestic structures. However, due to environmental changessuch as climate change and coastal topography changes, changes of airborne chlorides along the coast are expected to occurregionally and by sea area. Therefore, the second survey has been conducted since 2021. Inthis paper, we analyzed the seasonal variations of airborne chlorides along the coast by region and sea area for one year of the second survey. Additionally, we compared the results withthe survey results of Japan's coastal airborne chlorides, which islocated close to South Korea and has a similar climate, to increase the objectivityofthe analysis. The averageairborne chloridesin the second surveywas highest on the west coast, and the seasonal variation was also the largest on the west coast. Looking at the seasonal variations by sea area, the East Sea had highairborne chloridesinthe summer and autumn,theWestSea inthe autumnandwinter, and the SouthSea in the summer. In addition, compared to the firstsurvey, allsea areasshowed short periods ofsignificantly higher coastalsalinity and clearerseasonal variations.

A Study on the Seasonal Variation of Water Quality and Sediment Environment in Gwangyang Bay, Korea ($2004\sim2005$년 광양만의 해양수질 및 저질의 계절적 변동에 관한 연구)

  • Cho, Hyeon-Seo;Cho, Chon-Rae;Kang, Jo-Hae;Lee, Kyu-Hyong
    • Proceedings of KOSOMES biannual meeting
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    • 2006.05a
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    • pp.129-135
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    • 2006
  • This study was performed to characterize the seasonal variation of water quality and sediment environment from May, 2004 to February, 2006 in 21 stations of Gwangyang bay. Gawngyang bay is located in the middle of south coast of Korea and semi-dosed with Yeosu peninsula, Gwangyang-city and Namhea-do. Water quality at the west coast of Myo-do were highly deteriorated than other stations. At summer season(July 2005), the concentration of the most analytical items were highly detected than other seasons and the lowest concentration was at the winter season(January 2005, February 2006). Especially, DIP and TP were highly detected around the coast of Yeosu industrial complex. N/P ratio were higher than 16 of Redfield ratio in the spring(May 2005) and winter(February 2006) at the surface layer. While at other seasons and most stations were lower than 16 of Redfield ratio. In the survey of sediment environment, ignition loss(IL), chemical oxygen demand(COD) and acid volatile sulfide(AVS) were in the range of $2.51\sim22.10%,\;2.65\sim48.41mg/g-dry\;and\;0.01\sim8.95mg/g-dry$, respectively. COD in surface sediment was highest at summer season AVS was highest at autumn. In sediment, the corelationship coefficients between COD and IL, COD and AVS were 0.65 and 0.44, respectively.

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Seasonal Fluctuation and Vertical Microdistribution of Drosophilid Flies Dwelling in the Broad-Leaved Forests on Cheju-Do (Quelpart Island)* (제주도 활엽수림에 서식하는 초파리의 계절에 따른 변동과 수직 미분포)

  • 김원택
    • The Korean Journal of Zoology
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    • v.39 no.3
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    • pp.325-336
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    • 1996
  • Community organization of the drosophilid flies was investigated with respect to the seasonal variation in species abundance and vertical microdistribution on the basis of the trapped collections in the two natural forests on Cheju-do from May to October 1994. The dominant species were Drosophila bizonata, D. curviceps, D. lutescens, D. angu leris, D. tsigana and D. immigrans in the annual collections. The pattern in seasonal changes of the dominant species was similar at the two survey sites. Seasonal fluctuation in the species diversity was more affected by evenness than by species richness (number of species). The seasonal variation of abundance showed an unimodal pattern in all of the dominant species. The seasonal patterns of vertical microdistribution revealed difference in some of the dominant species between the two survey sites. These results suggest that the predominant species in the forest avoid niche overlap by means of seasonal separation of breedings and that the vertical microdistribution is strongly affected by factors associated with season and vertical site in the deep wooded forests.

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