• Korean Journal of Remote Sensing
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• v.17 no.2
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• pp.183-188
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• 2001

The NOAA AVHRR remotely sensed SST data, collected by the National Fisheries Research and Development Institute (NFRDI), are analyzed in order to understand the spatial and temporal distributions of SST in the sea near korea. Our study is based on 10-day SST images during last 7 years (1991-1997). For a time series analysis of multiple SST images, all of images must be consistent exactly at the same position by adjusting the scales and positions of each SST image. We devised an algorithm which automatically detects cloud pixels from multiple SST images. The cloud detection algorithm is based on a physical constraint that SST anomalies in the ocean do not exceed certain limits (we used $\pm$3$^{\circ}C$ as a criterion of SST anomalies). The remotely sensed SST data are tuned by comparing remotely sensed data with observed SST at coastal stations. Seasonal variations of SST are studied by harmonic fit of SST normals at each pixel and the SST anomalies are studied by statistical method. It was found that the SST anomalies are rather persistent for one or two months. Utilizing the persistency of SST anomalies, we devised an algorithm for a prediction of future SST. In the Markov lprocess model of SST anomalies, autoregression coefficients of SST anomalies during a time elapse of 10 days are between 0.5 and 0.7. The developed algorithm with automatic cloud pixel detection and rediction of future SST is expected to be incorporated to the operational real time service of SST around Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.1
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• pp.85-93
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• 2022

In this study, we investigated how satisfaction with on-board training had an effect on career motivation of the trainees. For this purpose, satisfaction for on-board training and career motivation were used as variables. Satisfaction for on-board training were classified into education, environment and operation, and then measurement items were composed. Career motivation consisted of career identity, career insight and career resilience. To establish and test nine hypotheses, a questionnaire survey was conducted by 57 trainees who participated in the Gyeongsang National University on-board sailing training in 2021. To analyze the questionnaire responses, frequency analysis, factor analysis, multiple regression analysis and paired sample t-test were used. As a result of factor analysis, six factors for satisfaction for on-board training were derived. Among the factors, it was analyzed that satisfaction with assignments, the satisfaction with accommodation, and the satisfaction with the adequate condition of facilities and equipment had a significant effect on career motivation. In addition, it was found that career motivation significantly increased through on-board training as a result of comparing the difference between the averages of career motivation before and after on-board training.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.668-679
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• 2023

Edwardsiella tarda is one of the most significant fish pathogens, causes edwardsiellosis in a variety of freshwater fish species, and its antibiotic resistance against multiple drugs has made it a health risk worldwide. In this study, we aimed to investigate the antibiotic resistance (ABR) genes of E. tarda and establish its antibiotic susceptibility. Thus, 540 fish (299 Oreochromis niloticus, 138 O. mossambicus, and 103 O. aureus) were collected randomly from twelve fish farms in three districts of Punjab in Pakistan. E. tarda was recovered from 147 fish showing symptoms of exophthalmia, hemorrhages, skin depigmentation, ascites, and bacteria-filled nodules in enlarged liver and kidney. Antimicrobial susceptibility testing proved chloramphenicol, ciprofloxacin, and streptomycin effective, but amoxicillin, erythromycin, and flumequine ineffective in controlling edwardsiellosis. Maximum occurrence of qnrA, blaTEM, and sul3 genes of E. tarda was detected in 45% in the liver, 58%, and 42% respectively in the intestine; 46.5%, 67.2%, and 55.9% respectively in O. niloticus; 24%, 36%, and 23% respectively in summer with respect to fish organs, species, and season, respectively. Motility, H₂S, indole, methyl red, and glucose tests gave positive results. Overall, E. tarda infected 27.2% of fish, which ultimately caused 7.69% mortality. The Chi-squared test of independence showed a significant difference in the occurrence of ABR genes of E. tarda with respect to sampling sites. In conclusion, the misuse of antibacterial agents has led to the emergence of ABR genes in E. tarda, which in association with high temperatures cause multiple abnormalities in infected fish and ultimately resulting in massive mortality.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.2
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• pp.235-244
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• 2015

The multi-frequency characteristics of anchovy schools were investigated using six acoustic lines collected at 38 and 120 kHz while a primary trawl survey was conducted from 14 April and 18 April of 2014 in off the coast of Tongyeong and Geo-je. Here, the frequency characteristics mean ${\Delta}MVBS$ that is the difference of Mean Volume Backscattering Strength at two frequencies. To use the characteristics effectively, the optimal cell size ($10{\times}2m$) was determined by examining several different cell sizes in consideration with the shapes of fish schools and the ${\Delta}MVBS$ pattern. By examining 6 histograms of ${\Delta}MVBS$, afternoon groups were occupied more in the ${\Delta}MVBS$ range of -6~-4 dB than that of -4~-2 dB, comparing to morning groups. The ${\Delta}MVBS$ range of the morning groups was between -16.9 dB and 11.6 dB, and that of the afternoon groups -16.7 dB and 13.0 dB. The average and standard deviation were $-3.9{\pm}3.6$ dB in the morning and $-4.1{\pm}3.4$ dB in the afternoon, suggesting that morning groups were 2 dB higher than afternoon groups. The ${\Delta}MVBS$ range of all anchovy schools regardless of morning and afternoon was between -16.9 dB and 13.0 dB, their average ${\Delta}MVBS$ was $-4.1{\pm}3.5$ dB. The characteristics can support to identify anchovy species in the waters where multiple fish species are distributed. It is hoped that this study presents the availability and benefit of acoustic data from a primary trawl survey.

• Journal of Life Science
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• v.26 no.9
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• pp.1007-1014
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• 2016

A highly efficient, rapid, and reliable multiplex polymerase chain reaction based method for distinguishing ten species of genus Cynoglossus (C. senegalensis, C. abbreviates, C. macrolepidotus, C. arel, C. semilaevis, C. interruptus, C. joyneri, C. lingua, C. robustus, and C. monodi) is described. The species-specific primer sets were designed base on the cytochrome oxidase subunit I gene (1,500 bp). The optimal PCR conditions and primers were selected for ten of Cynoglossus species to determine target base sequences using single PCR. Multiplex PCR using the ten pairs of primers either specifically amplified a DNA fragment of a unique size or failed, depending on each species DNA. The length of amplification fragment of 208 bp for C. senegalensis, 322 bp for C. abbreviates, 493 bp for C. macrolepidotus, 754 bp for C. arel, 874 bp for C. semilaevis, 952 bp for C. interruptus, 1,084 bp for C. joyneri, 1,198 bp for C. lingua, 1,307 bp for C. robustus, and 1,483 bp for C. monodi with the species-specific primers, visualized by agarose gel electrophoresis, allowed perfectly distinction of the Cynoglossus species. The multiplex PCR assay can be easily performed on multiple samples and attain final results in less than 6 hours. This technique should be a useful addition to the molecular typing tools for the tentative identification of Cynoglossus species.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1252-1264
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• 2015

This study examined the moderating and mediating effects of teacher-child conflict relationship among child's language ability, emotional regulation and peer victimization. The participants were 152 children(77 boys, 75 girls) and 14 preschool teachers. The teachers completed rating scales to measure the child's emotional regulation, peer victimization and teacher-child relationship. Child's language ability was assessed by researcher using PRES(Preschool Receptive-Expressive Language Scale). The collected data were analyzed using Pearson correlations and hierarchical multiple regressions. Results showed that peer victimization was related to child's language ability, emotional regulation and teacher-child relationship. Hierarchical aggression analysis indicated that the interaction of child's receptive language ability and teacher-child conflict relationship predicated peer victimization. Child's language ability, whose demonstrated a lower teacher-child conflict relationship, was significantly with peer victimization. In addition, the association between a child's emotional regulation and peer victimization was partially mediated by teacher-child conflict relationship.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1273-1289
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• 2015

The purpose of this study was to use the parent of the infant status and their media perception (3-7 five years) the infants' media use by examining the situation looking at the parents' use of media that cause impact on infants' media use parents will be validated accordingly to seek the solutions for the media and the involvement of infants perception. U City and 14 practitioners in preschool infants aged 5-7 target parents from 1307 people based in September 2014, a survey was conducted two months until October. This study was a mixed Methods for quantitative analysis of all the results and qualitative analysis of the results. Results for media use quantitative analysis of the results and impact parents have on infants' media use their media usage status of the parents and the media use of infants by their perceived status has been subjected to frequency analysis and hierarchical multiple regression analysis, parents perception results. Analysis of the solution for the immersion of the media and the infants unit of analysis was used for componential analysis. Through this study, parents would like to establish a plan to take advantage of essential educational content in the media and sought ways for the correct use of infants in the media and practice at home.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.5
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• pp.405-413
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• 2004

The previous morphology-based taxonomic frameworks within the family Syngnathidae had emphasized the significance of the male brood pouch and reproductive biology in defining the group. However, several different hypotheses had been proposed by different investigators. This study has been carried out to determine the phylogenetic relationships among 19 species belonging to the order Syngnathiformes with three Gasterosteiformes species as outgroup taxa by using the mitochondrial cytochrome b DNA sequences. Phylogenetic analyses based on neighbor-joining distance, maximum parsimony, minimum evolution and maximum likelihood method strongly supported that the family Syngnathidae, the suborder Syngnathoidei and the order Syngnathiformes were all monophyletic group. Although much of previous morphological analyses were supported by our molecular data, there were some significant discrepancies between molecular and morphological work. Such an interesting result was that the weedy seadragon (Phyllopteryx taeniolatus) strongly grouped together with the New Zealand pot-belly seahorse (Hippocampus abdominalis). Considering the markedly different brooding structure between them, this unexpected result might be explained whether by multiple independent origins of brooding structure or by hybridization between the female Hippocampus and other syngnathid species having individual membranous egg compartment. In addition, the suborder Aulostomoidei was paraphyletic group because the shrimpfish (Aeliscus strigatus), belonging to the family Centriscidae, always grouped together with the family Syngnathidae as a sister taxon.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.1
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• pp.31-36
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• 2008

The underwater sound transmission system(USTS) was experimentally made to monitor the cetacean's appearance by telemetry, and then its system was tested to evaluate its performance from July to October, 2007 at the Kimnyeong berth and the dolphin's breeding ground of Pacific Land in Jeju island, respectively. The results showed that the sweep sound in the trial experiment and the whistle sound of bottlenose dolphin(Tursiops truncatus) were favorably received by telemetry. Therefore, we could confirm the USTS is able to monitor the cetacean's appearance in real time without direct observation at sea within effective range of code division multiple access(CDMA) communication method.

• Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.185-193
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• 2009

A complete cDNA, which encodes for a myostatin-like protein (Es-MSTN), was isolated from the Chinese mitten crab, Eriocheir sinensis. Es-MSTN was composed of 2,397 nucleotides and the open reading frame (ORF) specified a protein containing 468 amino acids. Es-MSTN exhibited 32% amino acid sequence identity and 52% similarity to human myostatin. Multiple sequence alignment analysis indicated that Es-MSTN possessed the conserved proteolytic cleavage site (RXXR) for maturation of the protein and nine cysteine residues for disulfide bridges. Besides the conserved structural features, Es-MSTN also exhibits its unique characters; a longer N-terminal domain which is involved in protein folding and latent form of myostatin and absence of the cleavage site for BMP-1/tolloid family of metalloproteinase to activate mature myostatin. Phylogenetic analysis suggests that Es-MSTN showed the closely related to both vertebrate myostatin and GDF11. Es-MSTN is expressed highly in the claw muscle, leg muscle, thoracic muscle and heart, and moderately in the hindgut suggesting that Es-MSTN may play important roles in the muscle tissues. As homolog of mammalian myostatin and GDF11, Es-MSTN may be involved in development of muscular tissue and further study will help to produce high-quality seafood.