• 한국환경과학회지
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• 제27권6호
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• pp.383-399
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• 2018

In the present study, the community distribution, functional feeding groups, and habitat groups of the benthic macroinvertebrates from Gayasan National Park were investigated at eight different sites from 2015 to 2016. The correlation between habitat altitude and each group type was analyzed statistically. Biodiversity indices, including dominance, diversity, richness, and evenness indices, were calculated. The results showed a total of 4,216 individual benthic macroinvertebrates were collected, including 4 phyla, 6 classes, 16 orders, 40 families, and 100 species. Gammarus sobaegensis was dominant with 0.141% dominance, and the subdominant species was Epeorus nipponicus with 0.088% dominance. The EPT group(Ephemeroptera, Plecoptera and Tricoptera) accounted for 71.00% of the total species and 67.69% of the total individuals. The number of scraper species was highest, and the number of gathering collector individuals was highest among functional feeding groups. The individual number of scrapers(r=-0.358, p < 0.05) and gathering collectors(r=-0.343, p < 0.05) decreased with increasing altitude. The numbers of species and individuals of clingers and sprawlers were highest among the habitat groups. The individual number of clingers(r=-0.547, p < 0.01) and burrowers(r=-0.331, p < 0.05) significantly decreased with increasing altitude. The diversity and richness indices were higher in St. 3 than in the other sites. The dominance index was highest in St. 2, and the evenness index was highest in St. 7. We evaluated the biological water quality with several known methods, and concluded that ESB(Ecological score of benthic macrovertebrates community) and GPI(Group polution index) were more suitable than KSI(Korean saprobic index) and BMI (Benthic macrovertebrate index) to assess the biological water quality of Gayasan mountain stream water.

• 한국정보통신학회논문지
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• 제16권3호
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• pp.626-634
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• 2012

양식 환경의 과학적이고 체계적인 관리와 양식어민을 위해 실시간 수질 및 급이 정보 이외에도 자료의 종합적인 판단과 변화 이력을 확인하고 관리할 수 있는 시스템이 필요하다. 따라서 본 연구에서는 양식장의 수질, 급이의 현재 상태를 제시하고 이력 정보를 기반으로 시뮬레이션 가능하며 상태 변화를 단계 별로 확인 가능한 시스템을 비주얼 C++를 이용하여 구현하였다. 또한 수질, 급이 상태 정보를 수산지식을 기반으로 종합적으로 분석할 수 있고 제시할 수 있는 엔트로피 모델을 제안하였다. 이는 추후 질병 및 다양한 연구 결과를 반영한 고차원의 양식 환경 모델을 생성할 수 있는 토대가 될 수 있다.

• 수산해양기술연구
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• 제55권1호
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• pp.20-28
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• 2019

The feeding habits of Pacific bluefin tuna, Thunnus orientalis were analyzed using samples by large purse seine fishery in Korean waters from 2012 to 2017. The number of samples was 1,274 and the fork-length (FL) ranged from 34.6 to 218.0 cm. According to %IRI, the Important main prey items of immature individuals (below 91.4 cm in FL) were Pisces, Cephalopoda and Euphausiacea and those of mature individuals were Cephalopoda and Pisces. T. orientalis showed ontogenetic changes in prey item that Pisces was dominated in size class of 30-89 cm (FL), Cephalopoda in 90-179 cm (FL), and Pisces above 180 cm. As for seasonal changes in prey item, Cephalopoda was dominant in spring and Pisces was dominant in summer, autumn and winter. %F, %N, %W and %IRI cluster analysis divided area into three groups: Group A was dominated by Pisces; Group B was dominated by Cephalopoda, and Group C was dominated by Euphausiacea.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.167-170
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• 2015

본 논문에서는 바쁜 현대인들뿐만 아니라 노인 및 어린이들이 보다 편안하고 효율적으로 애완동물을 기를 수 있도록 하기 위한 애완동물 배뇨 훈련 및 먹이 자동 공급을 위한 시스템을 제안한다. 이 시스템은 블루투스를 이용해 스마트폰 어플리케이션으로 조작할 수 있도록 하며, 나아가 Wifi를 통해 인터넷에 접속하여 어디서든 조작할 수 있도록 한다. 본 논문의 시스템은 배뇨판과 먹이 공급기로 나뉘어져있다. 배뇨판은 배뇨 인식을 위한 수압 센서와 음성출력을 위한 녹음기 모듈, 스피커로 구성되고 후면부는 먹이 자동 공급을 위한 두 개의 서보 모터와 원격 통신을 위한 블루투스 센서로 구성된다. 배뇨판과 먹이 공급기 모두 아두이노 보드와 C언어 기반의 아두이노 스케치 프로그램으로 제작하였으며 먹이 공급기는 블루투스 통신을 지원하는 라이브러리로 통신할 수 있게 하였다. 구현된 시스템은 애완동물의 종류 및 크기에 관계없이 자동 수위조절과 먹이양이 조절되는 특징을 가진다.

• 한국수산과학회지
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• 제47권4호
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• pp.399-405
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• 2014

We investigated the effects of feeding rate on the growth performance, blood components, and histology of growing olive flounder Paralichthys olivaceus. Optimum feeding rate (initial fish mean weight : $316.7{\pm}6.18g$) was determined under the optimum water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.4%, 0.6%, and 0.8% of body weight (BW) per day, and to satiation. Feeding trial was conducted using a flow-through system with 10 1.2-metric ton aquaria receiving filtered seawater at $21-24^{\circ}C$ for 3 weeks. Weight gain (WG) and specific growth rate (SGR) were significantly higher in fish fed to satiation (1.0% BW/day) than in those in other treatments. These parameters were negative and significantly lower in the starved fish than in fish fed the experimental diet at all feeding rates. There were no significant differences in WG and SGR among fish fed at 0.4%, 0.6%, and 0.8% BW/day. Hematocrit and hemoglobin in fish fed to satiation were significantly lower than those in other treatments. Histological changes of fish fed at 0.6% BW/day indicated that this group was in the best condition; differences were not found in tissues of fish fed at 0%, 0.6% and 1.0% BW/day. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 317 g was 0.99% BW per day at the optimum water temperature.

• 한국수산과학회지
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• 제47권6호
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• pp.1063-1068
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• 2014

We investigated the effects of feeding rate on the growth performance and blood components of sub-adult olive flounder Paralichthys olivaceus. Optimum feeding rate (initial fish mean weight : $370{\pm}5.72g$) was determined under the low water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.3%, 0.4%, 0.5%, and 0.6% body weight (BW) per day, and to satiation (0.75%). Feeding trial was conducted under a flow-through system with 12 1.2-metric ton aquaria receiving filtered seawater at $12-14^{\circ}C$ for 4 weeks. Weight gain (WG) and specific growth rate (SGR) for fish fed at 0.6% BW per day was significantly higher than that of unfed fish (0%) and fish fed at 0.3% and 0.4% BW per day. There were no significant differences in WG and SGR among fish fed at 0.5%, 0.6%, and 0.75%. These parameters were negative and significantly lower in the starved fish than in fish fed the experimental diet at all feeding rates. Survival for unfed fish (0%) was significantly lower than that of fish fed at 0.4%, 0.5%, and 0.6%. Hematocrit and hemoglobin content of fish fed at 0% and 0.75% (satiation) were significantly lower than that of fish fed at 0.4% BW per day. Total protein content in unfed fish was significantly lower than those in other treatments. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 370 g was 0.51% BW per day at the low water temperature.

• 동력기계공학회지
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• 제9권1호
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• pp.36-41
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• 2005

This study investigated the performance of a vortex hydrocyclone for solid removal in a recirculating aquaculture system. In a fish-breeding industry, effluent water is mainly disposed by gravity sedimentation. Thus, a large settling tank and a lot of water are needed to purify effluent water. However, this typical method does not show consistent efficiency. In case of low efficiency, discharged water contains a lot of feeding sediments. This causes environmental problems. Instead of this typical method a hydrocylone is tested to discharge water which contains a lot of feeding sediments. In this paper, a hydrocyclone with low velocity and pressure drop in a recirculating aquaculture system is investigated.

• 한국염색가공학회지
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• 제24권1호
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• pp.62-68
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• 2012

Cellulose was electrospun over water collector and the cellulose solution was prepared using N-methyl-morpholine N-oxide/water(nNMMO/$H_2O$). The morphology of electrospun cellulose was investigated by scanning electron microscopy (SEM). SEM images showed that the fiber formation depended on processing parameters such as solution concentration, applied electric field strength, solution feeding rate and temperature of water in coagulation bath. High concentration, low temperature of water bath, and low feeding rate were more favorable to obtain fiber morphology. All the variables affected on the fluidity of the cellulose solution and diffusion of NMMO. Low fluidity and fast diffuision of NMMO was critical for obtaining fiber morphology.

• 한국패류학회지
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• 제30권2호
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• pp.101-106
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• 2014

인공종묘로 생산된 동죽, Mactra veneriformis의 크기, 수온, 염분 변화에 대한 여수율과 먹이섭이량의 차이를 조사하였다. 수온의 경우 소형, 대형그룹의 여수율은 $5^{\circ}C$에서 최소값을 보였으며 $20^{\circ}C$에서 가장 높은 값을 보였으나, $25^{\circ}C$에서 급격한 감소 경향을 보였다. 염분에 대한 소형그룹의 여수율은 26‰에서 가장 높은 값을 보였고 8‰에서 가장 낮은 값을 보였다. 대형그룹은 32‰에서 가장 높은 값을 보였고, 8‰에서 가장 낮은 값을 보였다. 본 연구를 통해 동죽의 최적 수온, 염분 환경은 $20^{\circ}C$, 27-32‰이며, $10^{\circ}C$ 이하 또는 $25^{\circ}C$ 이상의 수온과 20‰ 이하의 저염분에서 여수율이 낮아진다는 사실을 확인할 수 있었다.

• 한국물환경학회지
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• 제20권1호
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• pp.48-54
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• 2004

Two methods, a Ceriodaphnia algal uptake suppression test (CAUST) and a new toxicity test based on temperature control (TTBTC) which are based on feeding behaviour and temperature control, respectively, were developed and compared for the adoption as the better methodology for short-term toxicity screening. As previously published by Lee et aI., (1997), the CAUST method is based on the feeding behaviour of C. dubia and requires as little as 1 hour of contact time between C. dubia neonates and toxicant. However, even though CAUST requires only 1 hour of contact time, this method still take many hours for the preparation and measurement. Before the test starts, neonate digestive tracts were cleared by feeding yeast to the daphnids, Neonates were then exposed to toxicant, followed by addition of Scenedesmus subspiatus into the bioassay vessels. Daphnids were examined under the bright-field microscope with the presence of algae (indicated by a green colored digestive tract) or the absence of algae. Uptake indicated no toxic effect, whereas, absence of uptake indicated toxic inhibition. Unlike CAUST, the newly developed method (TTBTC) is based on just temperature control for the toxicity test of C. dubia. Initially, neonates are exposed to toxicants while the temperature of water bath containing media increased to $35.5^{\circ}C$. After 1.25 hour of contact time, the number of the daphnids, either live (no toxic effect) or dead (toxic effect), is counted without the aid of any instrument. In both methods, median effective concentrations ($EC_{50}$ values) were computed based on the results over a range of dosed toxicant concentrations. It showed that TTBTC was as sensitive as the standard 48-hour acute bioassay and CAUST. TTBTC and CAUST were much more sensitive than the I-hour I.Q. test and 30-minute Microtox. This study indicates that TTBTC is an easier and more rapid toxicity test than the standard 48-hour acute bioassay and even CAUST.