• 수산해양기술연구
• /
• 제46권4호
• /
• pp.335-345
• /
• 2010

Species composition and seasonal variation of fish assemblage in Sacheon marine ranching, Korea were examined. Sampling was seasonally made by a shrimp trawl from February 2009 to November 2009. A total of 55 species were collected. Of these, five species was dominant species comprising 51.1% of the total number of individuals. Nine species represented 57.3% of the total biomass. While total abundance (number of individuals) was high in spring, total biomass and species richness (number of species) and diversity were high in autumn. Cluster analysis, based on seasonally abundance data of the 21 most common species, showed that the species were separated into 4 different groups. Group A composed of Pholis nebulosa, Pleuronectes yokohamae, Hypodytes rubripinnis, Hexagrammos otakii, Tridentiger trigonocephalus and Paracercis sexfasciata, which were year round residents, group B Congr myriaster, Leiognathus nuchalis, and Platycephalus indicus, which were abundant in autumn, group C Sillago japonica, Pseudaesopia japonica, Zoarces gilli, Pholis fangi, and Pleuronichthys cornutus which were abundant in spring, and group D Sillago sihama, Cociella sp., Johnius grypotus, Cynoglossus joyneri, Cynoglossus robustus, and Pennahia argentata, which were abundant in summer. Principal component analysis revealed that seasonal variation in the fish assemblage was attributed to the abundance of temporal species such as conger and sand smelt fishes, which were abundant in summer, due to seasonal variation of water temperature.

• 한국수산과학회지
• /
• 제38권1호
• /
• pp.20-28
• /
• 2005

Species composition and seasonal variation of decapod crustacean assemblage in Hampyeong Bay, Korea were examined. Sampling was monthly made by a shrimp trawl between March 2003 to February 2004. A total of 39 species of 20 families were collected. Of these, Latreutes planirostris, Palaemon gravieri, Parapenaeopsis tenella, Exopalaemon carinicauda, Charybdis japonica, Trachysalambria curvirostris and Palaemon macrodactylus were dominant species comprising $84.3\%$ of the total number of individuals. Charybdis japonica, P. gravieri, Oratosquilla oratoria, E. carinicauda, T curvirostris, Metapenaeus joyneri and P. tenella represented $90.6\%$ of the total biomass. While total abundance (number of individuals) was high in spring, total biomass and species richness (number of species) and diversity were high in summer. Cluster analysis, based on monthly abundance data of the 14 most common species, showed that the species were separated into three different groups. Group A composed of Leptochela gracilis, Alpheus japonicus, Crangon uritai, P. macrodactylus, E. carinicauda, P. gravieri, O. oratoria, C. japonica, which were year round residents, group B M. joyneri, T. curvirostris and P. tenella, which were abundant in summer, and group C Crangon hakodatei, Latreutes anoplonyx and L. planirostris, which were abundant in winter. Principal component analysis revealed that seasonal variation in the decapod crustacean assemblage was attributed to the abundance of temporal species such as penaeid shrimps, which were abundant in summer, due to seasonal variation of water temperature and reproductive pattern.

• 한국양식학회지
• /
• 제19권4호
• /
• pp.236-241
• /
• 2006

남해안에 서식하는 왕우럭의 공생성 요각류 3종의 감염률에 대한 계절 변동을 연구하였다. 계절에 따라서 감염률과 출현량의 차이를 보였으며, 겨울철에 높게 출현하였다. 요각류의 출현 양상에 따른 생산력은 성숙한 요각류의 비율이 높아지면서 초가을과 봄에 높게 나타났다. 공생성 요각류 3종의 출현 빈도는 숙주의 개체군이 성장할 수 있는 서식 조건에 따른 적합한 환경이 되어야 높아지는 것으로 나타났다. 공생성 요각류의 계절에 따른 감염률, 상대 감염강도, 평균 감염밀도는 수온과 그들의 생활사에 기인한 것으로 판단된다.

• 한국해양학회지
• /
• 제25권4호
• /
• pp.229-239
• /
• 1990

천수만의 동물플랑크톤을 채집, 분석하여 그 종소성와 수도(數度)에 있어서의 계 절변화와 Copepoda의 연간 생산량이 규명되었다. 종조성과 수도의 현저한 계절 변동과 함께 Paracalanus indicus 및 Corycaeus affinis가 여름에서 가을에 걸쳐 우점하는 반 면, Centropages abdominalis 와 Acartia omorii가 봄에 우점함을 보인다. 동물플랑크 톤의 수도는 3월에 최소치를 나타내고 이어서 점점 증가하여 8월에 최대치에 도달한 다. 연구해역에서 동물플랑크톤의 계절변화는 식물플랑크톤의 크기 및 양의 변화와 수 온에 의해 주로 영향을 받음이 알려졌다. Copepoda의 연간 총 생산량은 건조 중량으로 134g/100m$^3$로 추정되었으며 타 해역에 비해 높은 생산성을 나타낸다.

• 한국수산과학회지
• /
• 제43권5호
• /
• pp.503-509
• /
• 2010

The seasonal and interannual variation in the species composition and abundance of the decapod assemblage (shrimps, crabs, and hermit crabs) collected using pots in the coastal waters off Gori were studied between 2005 and 2008. During the study period, 49 decapod species belonging to 19 families were collected. The dominant species were Crangon hakodatei, Pandalus gracilis, Carcinoplax longimana, Charybdis bimaculata, Carcinoplax vestita, Diogenes edwardsii, and Dardanus arrosor. These seven species accounted for 95.46% of the total number of individuals collected. The number of species, number of individuals, biomass, and species diversity indices fluctuated with the seasons. The peak number and biomass of individuals occurred in July 2006. The number and biomass of individuals were higher in summer and lower in winter, and the diversity indices were lower in summer than in the other seasons. The abundance of dominant species showed some seasonal and interannual change; in particular, those of C. hakodatei and P. gracilis corresponded with the bottom water temperature.

• Geomechanics and Engineering
• /
• 제36권4호
• /
• pp.391-406
• /
• 2024

In order to study the soil seasonal dynamic characteristics in the regions with four distinct seasons, the soil dynamic triaxial experiments were conducted by considering the environmental temperature range from -30℃ to 30℃. The results demonstrate that the dynamic soil properties in four seasons can change greatly. Firstly, the dynamic triaxial experiments were performed to obtain the dynamic stress-strain curve, elastic modulus, and damping ratio of soil, under different confining pressures and temperatures. Then, the experiments also obtain the dynamic cohesion and internal friction angle of the clay under the initial strain, and the changing rule was summarized. Finally, the results show that the dynamic elastic modulus and dynamic cohesion will increase significantly when the clay is frozen; as the temperature continues to decrease, this increasing trend will gradually slow down, and the dynamic damping ratio will go down when the freezing temperature decreases. In this paper, the change mechanism is objectively analyzed, which verifies the reliability of the conclusions obtained from the experiment.

• Ocean and Polar Research
• /
• 제35권2호
• /
• pp.181-191
• /
• 2013

To investigate the occurrence of modern living planktonic foraminiferal species and their seasonal variations around Jeju Island, we conducted planktonic foraminiferal sampling at KIOST's regular sampling sites during 16 months. In total seven genus and 16 modern planktonic foraminiferal species were identified with six dominant species. Dominant species were Gloigerinoides sacculifer, Globigerinoides ruber, Globigerina bulloides, Noegloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globorotalia inflata. Most of the species were characterized as being typical subtropical species and showed seasonal variations and/or intermittent occurrence from season to season. The occurrence of living foraminifera revealed a strong relationship with water temperature, but not with salinity. Species succession seems to occur along with water temperature changes. Some patch distribution and water temperature dependences appear to be significant since there is a high degree of variation in the occurrence patterns of species and standing stock. More detailed quantitative study is necessary to confirm the species diversity and seasonal variations of planktonic foraminifera and related ocean environmental changes.

• 펄프종이기술
• /
• 제48권3호
• /
• pp.91-98
• /
• 2016

Linerboards have been produced by recycling recovered paper such as old corrugated containers(OCC). Usually linerboards produced during summer season show weak strength compared with those of produced during winter. In order to cope with the weak strength of linerboards produced during summer, and to confirm uniform quality, it is important to understand the seasonal effect on strength properties. Effect of pulping temperature of the OCC for linearboard production was investigated by controlling pulping temperatures at $18^{\circ}C$ and $51^{\circ}C$. Low pulping temperature ($18^{\circ}C$) caused more generation of fines in stock. Consequently retention and drainage of linerboard defibrated at high pulping temperature ($51^{\circ}C$) were better than those of $18^{\circ}C$. Strength properties of handsheet at low pulping temperature were higher than those of high pulping temperature and it could be confirmed that low pulping temperature during winter is one reason of seasonal variation of recycled linerboard strength. It is considered that surface modification of OCC fibers by harsh pulping action during winter caused increase of paper strength.

• Journal of Ginseng Research
• /
• 제24권2호
• /
• pp.83-88
• /
• 2000

6년생 고려인삼근(Panax ginseng C.A. Meyer) 중의 Sucrose synthase, UDP-glucose pyrophosphorylase 및 ADP-glucose pyrophosphorylase의 활성을 생육 시기별로 조사한 결과, Sucrose synthase 와 ADP-glucose pyrophosphorylase는 뿌리저장활성 지표로서 adaptive enzyme의 특성을 나타내는 반면, UDP-glucose pyrophosphorylase는 maintenance enzyme으로서 존재하였다. 평균기온이 24。C 이상일 때 전분합성이 저하되고 중심부의 산소소비량이 급격히 증가되었다.

• 한국어류학회지
• /
• 제35권4호
• /
• pp.294-304
• /
• 2023

가덕도 인근해역에서 출현하는 자어 군집에 대한 계절변동을 파악하기 위해 2019년 5월, 8월, 11월 그리고 2020년 2월에 조사를 실시하였다. 조사기간 동안 자어는 총 45과 85개 분류군이 출현하였다. 우점종은 멸치(Engraulis japonicus), 망둑어류(Gobiidae spp.), 청어(Clupea pallasii), 가라지(Decapterus maruadsi), 돛양태류(Callionymidae sp.) 등으로 나타났으며, 이들 5종은 조사기간 중 출현한 자어 전체 출현개체수의 84.1%를 차지하였다. 멸치와 망둑어류, 가라지, 돛양태류는 여름철 우점종이었고, 청어는 겨울철 우점종이었다. 종다양도지수는 여름철에 가장 높고 가을, 겨울철로 갈수록 낮아졌으며, 봄철에 가장 낮은 값을 나타내었다. 조사기간 동안 출현한 자어의 출현개체수로 군집분석을 실시한 결과 계절에 따라 4개의 그룹으로 뚜렷이 구분되었다. 특히, 계절적 수온변화에 따라 여름철에는 자어의 적정한 성육환경이 형성되었고, 겨울철에는 겨울산란어종의 적정한 부화수온이 형성되어 자어군집의 계절적 특성을 반영하고 있었다.