• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.648-653
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• 2012

The present study examined the effects of dietary supplementation with nucleotide (inosine monophosphate product, IMP) on the growth performance, feed utilization, and non-specific immune responses of juvenile tilapia Oreochromis niloticus. Triplicate groups of tilapia (initial body weight, $7.4{\pm}0.04$ g) were fed experimental diets containing 0%, 0.05%, 0.1%, and 0.2% IMP. Fish were fed six times a day until apparent satiation for 13 weeks. At the end of the feeding trial, final body weight and food utilization of fish fed 0.1% IMP were significantly higher than those of fish fed the control diet. Results of hematological parameters were not affected by dietary IMP. However, blood protein level was significantly higher in the 0.05% treatment, as compared to that of the control and 0.2% IMP diets. Myeloperoxidase activity was higher in fish fed 0.1% IMP than in fish fed the control and 0.2% IMP diets. These results suggest that dietary supplementation with IMP can enhance the growth performance, feed utilization, and innate immune response of juvenile tilapia. The optimal IMP supplementation level appears to be 0.1% in practical feed formulations for tilapia.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.16-22
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• 2021

This study investigated the reduction in human norovirus (HNV) GII. 4 count in pacific oyster Crassostrea gigas using electron beam irradiation. Infectious HNV GII. 4 was detected using RT-qPCR (real time reverse transcription-quantitative polymerase chain reaction) with PMA (propidium monoazide)/sarkosyl. At electron beam doses 1, 5, 7, and 10 kGy, the count of HNV GII. 4 was 2.74, 2.37, 2.06, and 1.55 log copies/μL (control, 3.01 log copy/μL), respectively, confirming that as the irradiation dose increased, norovirus count reduced significantly (P<0.05). After PMA/sarkosyl treatment, the counts further reduced at the same irradiation dose, and 10 kGy showed significant differences between the non-treated and PMA/sarkosyl-treated samples (P<0.05). The Ed (decimal reduction dose of electron beam) value based on the first-order kinetic model was 7.33 kGy (R2=0.98). No significant difference was observed in the pH values of the control (6.2) and electron beam-irradiated samples at all doses (6.1). For sensory evaluation, the non-treated sample scored the highest in all categories (5.25-6.17), while the samples treated with 10 kGy showed the lowest score (4.67-5.33), although without statistical significance (P>0.05). Overall, our results suggest that 7 kGy electron beam is sufficient for the non-thermal sterilization of oysters without causing significant changes in quality.

• Korean Journal of Remote Sensing
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• v.38 no.1
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• pp.73-82
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• 2022

Marine fisheries resources face major anthropogenic threat from unregulated fishing activities; thus require precise detection for protection through marine surveillance. Korea developed an efficient land-based small fishing vessel monitoring system using real-time V-Pass data. However, those data directly do not provide information on fishing activities, thus further efforts are necessary to differentiate their activity status. In Korea, especially in Busan, longlining is practiced by many small fishing vessels to catch several types of fishes that need to be identified for proper monitoring. Therefore, in this study we have improved the existing fishing status classification method by applying Hidden Markov Model (HMM) on V-Pass data in order to further classify their fishing status into three groups, viz. non-fishing, longlining and other types of fishing. Data from 206 fishing vessels at Busan on 05 February, 2021 were used for this purpose. Two tiered HMM was applied that first differentiates non-fishing status from the fishing status, and finally classifies that fishing status into longlining and other types of fishing. Data from 193 and 13 ships were used as training and test datasets, respectively. Using this model 90.45% accuracy in classifying into fishing and non-fishing status and 88.23% overall accuracy in classifying all into three types of fishing statuses were achieved. Thus, this method is recommended for monitoring the activities of small fishing vessels equipped with V-Pass, especially for detecting longlining.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.5
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• pp.609-616
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• 2003

The purpose of this study is to design the adaptive speed control system of a marine diesel engine by combining the Model Matching Method and the Nominal Model Tracking Method. The authors proposed already a new method to determine efficiently the PID control Parameters by the Model Matching Method. typically taking a marine diesel engine as a non-oscillatory second-order system. But. actually it is very difficult to find out the exact model of a diesel engine. Therefore, when diesel engine model and actual diesel engine are unmatched as an another approach to promote the speed control characteristics of a marine diesel engine, this paper Proposes a Model Reference Adaptive Speed Control system of a diesel engine, in which PID control system for the model of a diesel engine is adopted as the nominal model and Fuzzy controller and derivative operator are adopted as the adaptive controller.

• 한국전산유체공학회:학술대회논문집
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• 2003.08a
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• pp.188-193
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• 2003

The present work solved 3D incompressible RANS equation on a rotating, non-orthogonal multi-blocked grid system to efficiently analyze ducted marine propulsor with rotor-stator interaction. To handle the interface boundary between a rotor and a stator maintaining the conservative property, the sliding multiblock technique using the cubic spline interpolation and the bilinear interpolation technique were applied. To validate present code, a turbine flow having rotor- stator interaction was simulated. Time averaged pressure coefficients were compared with experiments and good agreement was obtained. After the code validation, the flowfield around a single-stage ducted marine propulsor was simulated.

• Journal of Ocean Engineering and Technology
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• v.29 no.5
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• pp.373-379
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• 2015

Side Scan Sonar (SSS) is capable of acquiring real-time data for seabed scouring, bathymetry, mine countermeasurement, etc. In a shipyard, an SSS package is utilized to measure the water depth and find debris in the sea because a sufficient water depth and non-interruption have to be ensured before implementing an underwater installation such as a large thruster. This paper presents the application and operation method of an SSS for the construction of an offshore project.

• The Journal of Fisheries Business Administration
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• v.54 no.2
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• pp.15-29
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• 2023

This study aims to establish a development strategy for higher education in Indonesia's marine and fisheries sector and to present a direction for international development cooperation through evaluating policies and current problems related to higher education in marine and fisheries sector. To achieve the goals of human resources development in marine and fisheries sector, Indonesian government needs to secure non-salary expenditures to strengthen support for areas directly related to the effects of education, such as improving educational facilities, expanding scholarships, and so on. Education institution needs to develop effective teaching methods and systematic practice-based curriculum that reflects the needs of the local fishermen community and fisheries industry. In addition, it is necessary to support the supply of manpower throughout the fisheries industry. Fisheries industry needs to stop relying on the government or education institutions to secure excellent human resources and actively participate and cooperate in the education field so that excellent human resources can flow into the industry. Based on this strategy, international development cooperation for human resources development in Indonesia's marine and fisheries sector should focus on qualitative rather than quantitative expansion of higher education institutions.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.115-115
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• 2017

• Journal of fish pathology
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• v.23 no.2
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• pp.177-187
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• 2010

The Interferon stimulated gene 15 (ISG15) is strongly induced in many cell types by IFNs, viral infections, and double-stranded RNA (poly I:C). The ISG15 homologue cDNA was isolated from the rock bream LPS stimulated leukocyte cDNA library. The rock bream ISG15 homologue was found to consist of 833 bp encoding 157 amino acid residues. Compared with other known ISG15 peptide sequences, the most conserved regions of the rock bream ISG15 peptide were found to be the tandem ubiquitin-like domains and a C-terminal LRLRGG conjugating motif, characteristic of mammalian and non-mammalian ISG15 proteins. Phylogenetic analysis based on the deduced amino acid sequence revealed a homologous relationship between the ISG15 sequence of rock bream and that of Atlantic salmon, Atlantic cod, northern snake head, black rockfish and olive flounder. The expression of the rock bream ISG15 molecule was induced in the peripheral blood leukocytes (PBLs) from 1 to 24 h following poly I:C stimulation, with a peak at 3 h post-stimulation. The rock bream ISG15 gene was predominantly expressed in the PBLs, spleen and gill.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.614-620
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• 2009

We report non-specific immune responses and its disease resistance against Edwardsiella tarda by alga mixture (HE; Hizikia:Ecklonia) in olive flounder for the first time. Five isonitrogenous (44% crude protein) and isocaloric (17.1 MJ $kg^{-1}$) diets were formulated to have 0%, 2%, 4%, 6% and 8% of the alga mixture. One of five experimental diets was fed triplicate groups of fish (30 fish/group) to apparent satiation in a flow through system. After a two week feeding, blood was sampled at 3, 6, 12, 24 h after the last feeding for a kinetic measurement of nitroblue tetrazolium (NBT) activity and healthy fish with similar sizes in each tank were selected and injected with 1 mL of E. tarda suspension ($1.0\times10^7$ CFU/mL) to evaluate the disease resistance of the fish. Dietary supplementation of alga mixtures resulted in significantly higher non-specific immune responses compared with the fish fed the control diet. The cumulative mortality was significantly lower in the fish groups fed alga mixture containing diets than control group in the challenge test with E. tarda. Therefore, the results in this study indicate that dietary supplementation of Hizikia and Ecklonia mixtures enhance the non-specific immune responses and a disease resistance of olive flounder.