• The Journal of Fisheries Business Administration
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• v.25 no.2
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• pp.115-145
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• 1994

The objetives of this study are to find the economic feasibility of the polyculture and to give the economic information of the polyculture for aquaculture fishermen. The polyculture is defined as the rearing of several species together to make more efficient use of the growing space and the total ground environment. The economic feasibility analysis in the polyculture involves the profitability, the productivity, and the risk reduction effect. The results of the economic feasibility analysis in the polyculture are as follows; First, in the profitability analysis, the solid utilization of ground in the polyculture is more profitable than the monoculture. The profitability owing to the plane utilization of the ground in the polyculture is positioned between those of the monoculture of each speices. Second, in the productivity analysis, oyster and sea squirt are diminishing returns to scale. Third, the variation on the average rate of return in the polyculture products is smaller than that of the monoculture. Finally, the result of comparison between the polyculture and the monoculture shows that the polyculture in coastal area is more profitable and more efficient than the monoculture. Most of cultivating species are selective in their diet Thus, stocking different kinds of cultivating species will efficiently utilize space and food It seems that polyculture is more appropriate for those species that live in different ecological niches. We think that the production per unit of ground can be increased, and the fixed cost per unit of output be reduced, so the polyculture is more profitable than the monoculture. Based on the above results, we concludes that the polyculture is economically feasible when profitability and productivity are increased and simultaneously the variation of average rate of return in the polyculture is smaller than that of the monoculture.

• The Journal of Fisheries Business Administration
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• v.35 no.2
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• pp.31-51
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• 2004

The reduction of fishing grounds due to the establishment of EEZ system among China, Japan and Korea together with the depletion of fish resources by pollution of waters and successive reclamation projects along the east and the south coastal lines has made many problems in coastal communities including the decrease of population, the deepening aging phenomenon in the fishery society and the fall of relative income level compared with those of rural and urban residents. Especially, the income level of a fishing household is 90%. of a rural resident and 70% of a urban resident. The income of a fishing household consists of 55% of fishing income, 20% of a agricultural source, 20% of income from non-fishing areas, and 10% of transferred income. Compared with that of a Japanese fishing household which has more diverse income sources such as 62% of income coming from non-fishing areas through being hired in manufacturing firms, etc., that of Korean ones is highly dependent upon fishery and agriculture, so that the diversification of income sources is urgently needed, especially in non-fishing areas. This paper shows that as a model to upgrade fisherman's income level, firstly, it is necessary to enhance the value-added of fishing products through processing and new innovation of distribution process and, secondly, to promote tourism in fishing villages. To ascertain this model, a questionnaire survey to fishermen was carried out and showed that they expressed a strong support for the increase of income by the value-added process through processing and innovative distribution system and the active introduction of tourism in fishing villages. A case study on Gosan cooperative in Jeju was also introduced to identify the rationale of the suggested model and this study proved the validity of the model again. Conclusively speaking, to level up the fisherman's income requires the value- added activities through the introduction of product processing and new distribution system together with the introduction of marine tourism in fishing villages.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1319-1328
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• 2016

Since Ballast Water Management Convention has been effected, BWTS, applied to new-building vessels and existing vessels, have been developed from many countries with various treatment methods. However, BWTS is mainly typed Electrolysis, Ozone and UV type. Approximately 70 products have been type approved by the Flag Administrations. For the new-building vessels, the vessels' design and construction have been considered for arrangements and installations for BWTS. However, existing vessels which already construction had finished have problem with selection of BWTS type for installation and arrangement. The selection of the most economized BWTS system is important though, CAPEX has not been made any significant differences. However, OPEX is more important factor. Consequently, detail analysis of OPEX is the key to the selection of the most economized BWTS system and also it can be the purpose of this study. The feasibility study on the main three type of BWTS (Electrolysis, Ozone and UV type) for 175K Bulk Carrier and 57K Cargo ship has been conducted for this study. Because, these three type of BWTS have been the most frequently installed and used and the two type of object vessels are consist of the 40% of the world merchant ship market. For this study, interest rate, project duration (operation time after installation), maintenance cost and fuel oil price are considered as major factor of feasibility study. In addition, expecting Interest rates to sensitivity analysis conducted for more accurate feasibility study. For 175K Bulk carrier, ozone treatment system is more economical than other types. For 57K cargo ship, UV type is considered more economical than other types. However, it is concluded that electrolysis type is more suitable compare to installation space, total weight and electrical power consumption.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.1010-1015
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• 1995

Extent of reduction in protein digestibility by Godulbaegi(lxeris sonchifolia H.) kimchi powder appeared to be related to the kimchi weight-to-protein weight ratio, the kind of protein sources, part of plants and fementation period. In vitro digestibilities of protein were significantly(p<0.05) reduced as the freeze dried kimchi powder weight-to-protein ration increased from 0.5 : 1.0 to 1.0 : 1.0 for all Godulbaegi samples and protein sources. Overall digestibility of protein sources in the presence of kimchi powder, the reduction ranked in the following order : soybean>casein>beef>squid. Lower(p<0.005) reduction occurred for each protein source when raw plant was exchanged for kimchi products. Some greater reduction of digestibility was noted in young plants and leaf samples than ripe or root samples. Trypsin inhibitor, which expressed as soybena trypsin inhibitor, was inversely related(r=0.8437) to in vitro protein digestibility of casein in the presence of Godulbaegi kimchi powder. More than three times of total polyphenols contained in leaves than in roots. Young leaves had 30% more total polyphenols(37.64mg/g sample) than that in ripe ones. Soaking in 5% NaCl solution for 24 hrs was markedly reduced in total polyphenols as 73% for leaves and 33% for roots. Remarkable reduction in total polyphenols was not checked during fermentation followed after soaking. Trypsin inhibitor content correlated well(r=0.8873) with total polyphenols in all of Godulbaegi samples.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.4
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• pp.259-268
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• 2004

Keeping qualities of crude proteases (CP) and fractionated proteases (FP) sedimenting with $30\~80{\%}$ ammonium sulfate from four kinds of fish viscera as a seafood processing waste were examined. Azocaseinolytic activlties (pH 6 and 8) of CP from anchovy (Engraulis japonica), mackerel (Scomber japonicus), bastard flatfish (Pararlichthys olivaceus) and red sea bream (Chysorphys major) were stable without activity loss at $4^{\circ}C$ for 7 months. Activities of NaCP (CP containing $30{\%}$ sodium chloride) on azocasein were approximately $30{\%}$ lower than those of CP. FP activities Increased 3.4-16.1 folds compared to those of CP and NaCP Powdered crude protease (PCP) and fractionated and powdered protease (FPP) containing various sugars (lactose, sucrose, glucose and dextrin) were prepared by freeze drying. Activities of PCP and FPP containing sucrose were higher and more stable than those of PCP and FPP containing other sugars at $30^{\circ}C$ for whole keeping periods. PCP and FPP from mackerel viscera showed the highest proteolytic activity among four kind of fish vlsceras. The Optimum conditions and stabilities of FPP from mackerel viscera were pH 9 and $50^{\circ}C$, and pH 5-10 and $20-45^{\circ}C$, respectively. The results of this study suggest that FPP from seafood processing waste may be used as processing aids.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.2
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• pp.173-183
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• 2010

In a split beam echo sounder, the transducer design needs to have minimal side lobes because the angular position and level of the side lobes establishes the usable signal level and phase angle limits for determining target strength. In order to suppress effectively the generation of unwanted side lobes in the directivity pattern of split beam transducer, the spacing and size of the transducer elements need to be controlled less than half of a wavelength. With this purpose, a 50 kHz tonpilz type transducer with a half-wavelength diameter in relation to the development of a split beam transducer was designed using the equivalent circuit model, and the underwater performance characteristics were measured and analyzed. From the in-air and in-water impedance responses, the measured value of the electro-acoustic conversion efficiency for the designed transducer was 51.6%. A maximum transmitting voltage response (TVR) value of 172.25dB re $1{\mu}Pa/V$ at 1m was achieved at 52.92kHz with a specially designed matching network and the quality factor was 10.3 with the transmitting bandwidth of 5.14kHz. A maximum receiving sensitivity (SRT) of -183.57dB re $1V/{\mu}Pa$ was measured at 51.45kHz and the receiving bandwidth at -3dB was 1.71kHz. These results suggest that the designed tonpilz type transducer can be effectively used in the development of a split beam transducer for a 50kHz fish sizing echo sounder.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.4
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• pp.574-590
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• 2012

The purpose of this study is to analyze the 'Pleasant Life' textbook in the elementary school focused on the perspective of ethnocentrism and cultural relativism. The first- and second-grade textbook 'Pleasant Life' of the revised 2007 national curriculum was made to serve build up sound body and mind through activities and play together with different products and life culture which is associated with multicultural education. But in the global world that is changing to the multicultural area, the textbook 'Pleasant Life' has a tendency to not to be satisfied this current needs. The analysis criterion is made up six elements: understanding culture, self-identify, human equality, conquest of prejudice and collaboration. The results of analysis on contents related to the multicultural education in the elementary 'Pleasant Life' textbook for the 1st and 2nd grade are follows. The first, in the plenty of images and pictures, there are not diverse races in the textbook. Yellow race naturally command an overwhelming majority in the textbook images and pictures. Second, the 'Pleasant Life' has a few multicultural contents and if teacher would not have will for teaching multicultural contents, he can't teach multicultural education. Third, 'Pleasant Life' textbook has overmuch ethnocentrism contents which is expressed traditional play and folk songs. These contents lead to exclusiveness for other culture to students. In conclusion, it is needed to grow concerns for multicultural education and the national curriculum should offer precise guidelines on the direction and standards of multicultural education.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.3
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• pp.199-208
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• 2019

The present study compared the sensory and physicochemical characterizations of Alaska pollock Theragra chalcogramma roe according to the L, M, S, 2S, KA, KB, KC, and G grades. The mean weights of the Alaska pollock roe were 81.2 g (74.1-85.7 g) in the L grade, 48.4 g (41.1-54.8 g) in the M grade, 38.6 g (33.5-45.6 g) in the S grade, 29.3 g (25.7-34.2 g) in the 2S grade, 45.7 g (41.4-50.0 g) in the KA grade, 41.4 g (37.7-46.1 g) in the KB grade, 38.3 g (36.0-42.6 g) in the KC grade, and 15.0 g (14.2-15.6 g) in the G grade. The results of the sensory (transparency, physical damage, texture, and odor) and physicochemical (moisture, amino nitrogen and volatile basic nitrogen contents, Hunter redness, and texture) evaluations revealed that, in the normal group, the quality of Alaska pollock roe was highest in the L grade followed by the M, S, and 2S grades whereas, in the cut-group order, the quality was highest in the KA grade followed by the KB, KC, and G grades. The present results suggest that the L, M, S, 2S, KA, and KB grades could be used for high-quality Alaska pollock roe products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.121-126
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• 2019

Trimethylamine (TMA) is a nitrogen-based aliphatic organic compound. It is a major odorous component of fish and fishery products and is often used as an indicator of fish quality. The efficacy of TMA removal by various yeast strains was investigated. The five yeast strains found to be most effective in removing TMA were isolated from fermented foods and were identified as Saccharomyces cerevisiae based on biochemical and 18S rRNA sequence analyses. These strains were designated as S. cerevisiae SK1511, SK1512, SK1513, SK1514 and SK1515. Yeast cultures were treated with a TMA solution (0.3%, v/v), and the level of TMA reduction was analyzed by headspace gas chromatography. The five S. cerevisiae strains removed 32.02-50.34% of the TMA from the solution. This study is the first to demonstrate TMA reduction by microbial treatment.

• The Journal of Fisheries Business Administration
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• v.49 no.2
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• pp.21-35
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• 2018

Squid is a popular seafood in Korea. However, since the 2000s, the squid production has been declining. The unstable supply of the squid products may cause price fluctuations of fresh and chilled squid. These price fluctuations may be relatively more severe than them of other commodities, because the fresh and chilled squid can not be stored for a long period of time. Thus, this study analyzes the structural characteristics of price volatility and price asymmetry of fresh squid based on off-diagonal GARCH model. Data used to analysis of this study are daily wholesale and retail prices of fresh squid from January 1, 2006 to December 31, 2016 provided in the KAMIS. As theoretical approaches of this study, first of all, the stability of the time series is confirmed by the unit root test. Secondly, the causality between distribution channels is checked by the Granger causality test. Thirdly, the VAR model and the off-diagonal GARCH model are adopted to estimate asymmetry effect and price volatility spillover between distribution channels. Finally, the stability of the model is confirmed by multivariate Q-statistic and ARCH-LM test. In conclusion, fresh squid is found to have shock and volatility spillover between wholesale and retail prices as well as its own price. Also, volatility asymmetry effect is shown in own wholesale or retail price of fresh squid. Finally, this study shows that the decrease in the fresh squid retail price of t-1 period than the increase in the t-1 period has a greater impact on the volatility of the fresh squid wholesale price in t period.