• 수산경영론집
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• 제52권2호
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• pp.33-54
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• 2021

This study is aimed to analyze the economic feasibility of yellowtail culture using the copper alloy net cage in Gyeongsangbuk-do. First of all, in order to evaluate the copper alloy net cage on yellowtail culture, I review the trend on the yellowtail culture industry and research the concept of copper alloy net cage. The copper-alloy net cage is now recognized as an advantages of its system stability, recycling, antibiosis and food safety. The results were summarized as follows: first, there was significant meaning of the profit model of yellowtail culture by the price difference. Second, I analyzed in the economic feasibility of yellowtail culture using the copper alloy net cage, internal rate of return (IRR) was 51.58%, a benefit-cost ratio was shown to be 2.27 and net present value (NPV) was 1,087,337 thousand won, which indicates the economic feasibility of yellowtail culture using the copper alloy net cage is profitable. Finally, in order to improve the economic valuation, it is necessary to focus more on the developing of technology and cost reduction strategy on the copper alloy net cage.

• Fisheries and Aquatic Sciences
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• 제25권5호
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• pp.251-263
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• 2022

Sea cucumbers are worm-like, leathery bodied, benthic, marine organisms with a branched gonad. There are over 900 species, and these organisms are capable of changing their mechanical state, regenerating their small appendages, and digestive tract. Additionally, sea cucumbers possess both commercial and therapeutical value. Furthermore, it is thought that the metabolites these organisms possess may give rise to their therapeutical value. The use of sea cucumbers in therapy can be traced back to the Ming dynasty, where they were eaten for their tonic properties against constipation, hypertension, and rheumatism. A plethora of studies have been conducted, whereby different metabolites were extracted from sea cucumbers and tested for different therapeutic properties. Herein, we review and discuss the anti-cancer, anti-microbial, anti-coagulant, anti-diabetic, antioxidant, and anti-inflammatory properties of the sea cucumber by assessing literature on PubMed and Google Scholar. Furthermore, the genome and epigenome of these remarkable species is discussed. With the immense data supporting the therapeutic properties of sea cucumbers, further studies are warranted, in order to develop novel and innovative therapeutic compounds for the benefit of human health from these fascinating marine organisms.

• Fisheries and Aquatic Sciences
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• 제25권2호
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• pp.90-100
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• 2022

Cardiovascular diseases (CVDs) have posed serious public health problems, accounting for nearly 30% of mortality worldwide and their incidence is still increasing. Therefore, new treatment resources are necessary to prevent or manage the ever-increasing population of patients with CVDs. Sea cucumber is well known for its medical and health benefit effects, but it is not well known what/how effect it has on vascular disease. In the present study, we examined the protect effect of sea cucumber, Apostichopus japonicus 80% ethanol extract (AJE) on zebrafish embryo with the stimulation of free fatty acid, palmitate (PA). In vivo study showed that AJE can attenuate PA-induced toxicity through relieving the rapid heartbeat, increasing the survival rate and reducing the malformation in both wild type and Tg (fli1a:eGFP) transgenic zebrafish lines. Additionally, compare with PA treated embryos, the yolk sac area, body length, axial vascular segment (AVS) and intersegmental vessel (ISV) of the co-treatment group of AJE and PA were comparable to the control group. Moreover, AJE lowered the expression of inducible nitric oxide synthase (iNOS), nitric oxide (NO) and inflammation-related genes induced by PA, and inhibited PA-induced vascular development disorders. Our data preliminarily verify that AJE could be a candidate resource for the prevention or therapy of CVDs.

• 한국수산과학회지
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• 제19권5호
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• pp.436-445
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• 1986

As the second part of the studies on the utilization of polyunsaturated lipids in sardine oil as nutritional or medical supplement, the conditions of lipid extration and concentration, refining, and storage stability of EPA-condensed sardine oil were investigated. In extraction of lipids, solvent ratios of chloroform-methanol mixture(2:1 v/v) affected the final content of unsaturated lipid in extracted oil and recovery. Stepwise solvent fractionation method at various low temperatures was effective to concentrate polyenoic acids like EPA and DHA when acetone or acetone-methanol mixture, added in the ratio of 1:5 (v/v) was applied step by step to different temperatures at 0 to $-35^{\circ}C$. Addition of 1 to $5\%$ (v/v) of water to acetone was also benefit to raise EPA content but that resulted in reducing the yield of condensed oil from $65\%\;to\;28\%$. Concentration rate of polyenoic acids by solvent fractionation in lipid-actone solution (1:5, v/v) at 0 to $-30^{\circ}C$ seemed limited to $5{\sim}8\%$ in fatty acid composition depending on the initial content of those polyenoic acids in the sardine oil. During the extraction, concentration, and alkaline treatment, oxidation was rapidly induced but oxidation products could be thoroughly removed on the process of deceleration and peroxide elimination. To stabilize the reactive polyenoic acid condensed oil during the storage, stuffing nitrogen gas was essential to expel dissolved oxygen in oil or to seal the oil from open air, and the addition of antioxidative agents as BHA and tocopherols were greatly helpful to extend the storage life.

• 수산해양기술연구
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• 제51권2호
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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.

• Asian-Australasian Journal of Animal Sciences
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• 제9권3호
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• pp.241-245
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• 1996

A chronological account of the prospect and problems of utilization of urea in poultry diets is presented. Urea has long been considered as toxic to poultry but recent research, although limited, has yielded controversial results. The main problem appears to be due to the fact that whether or not response to urea is dependent on environment (germ free versus conventional). Although caecum is found to be the major site of ammonia production from urea, the so called nutritional benefit derived by chicken fed urea is probably limited to its utilization for the synthesis of nonessential amino acids in the protein depleted chicken, but not in the protein adequate chicken. More research is needed to monitor production characteristics of birds fed urea and investigate its toxic effect, if any, in some greater detail before recommending this nonprotein nitrogenous substance for inclusion in the poultry diets.

• Ocean and Polar Research
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• 제30권2호
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• pp.173-180
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• 2008

This study demonstrates that cooperative management can provide more benefits than noncooperative management for Korea and Japan fishery. We have studied one management strategy, namely, fishing under joint maximization of net benefits in coastal waters of two countries, using a cooperative game theory. The present net return under non-cooperation amounts to 420,255 million won. However, if two countries cooperate one with another, this figure can get to 2,636,565 million won. We consider this to be an important conclusion as close management relationships have developed between the two countries since the establishment of the EEZ in 1996. The results of the study can also help balance resource conservation and the appropriate catch quota in each country.

• 한국수산과학회지
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• 제21권2호
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• pp.71-79
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• 1988

미생물에 의해 속성 저식염젓갈을 제조할 목적으로 저식염멸치젓(식염 $4\%$, KCl $4\%$, lactic acid $0.5\%$, 솔비톨 $6\%$ 및 고추가루 알코올추출물 $4\%$)에서 단백질분해력이 강한 미생물을 분리하여 그 특성을 조사한 결과는 다음과 같다. 숙성 40일경의 시료를 취하여 skim milk배지상에서 HC ratio 2.5이상인 단백질 분해력이 강한 균주를 선별하여 동정한 결과 A. anaeregenes, B. subtilis, S. saprophyticus 3균주이었으며 모두 pH 7.0, $30^{\circ}C$에서 균증식 및 효소활성이 양호하였다. 이들 균 중 B. subtilisrbs이 비증식속도는 $0.95hr^{-1}$, 12시간 배양후 $89\mu{g}-Tyr/hr.ml$의 효소환성을 나타내어 분리된 균주 중 활성이 가장 좋았으며 산업적 응용성이 기대되었다. 그리고 gel여과법으로 정제한 B. subtilis 프로테아제의 특성은 pH 7.0, $35^{\circ}C$에서 활성이 가장 우수하였으며 분자량은 23,000으로 추정되었다. 또 카제인을 기질로 하여 효소반응 속도를 측정한 결과 Km값이 $0.73\%$이었다. 효소저해제의 효과에서는 EDTA, o-phenanthroline에 의하여 거의 실활되었으며, 금속 이온으로는 $Fe^{2+},\;Ni^{2+},\;Cu^{2+}$ 이온등에 의해 강하게 저해되는 것으로 보아 metal chelator sensitive neutral protease로 추정되었다.

• 한국수산과학회지
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• 제20권6호
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• pp.520-528
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• 1987

배소김의 열처리조건에 따른 성분의 변화와 저장중의 색소, 지방산, 유리아미노산, 색도, 갈변등의 변화를 측정하여 품질의 안정성을 검토한 결과를 요약하면 다음과 같다. 1. 열처리중 biliprotein 색소는 극히 불안정하였고, chlorophyll a 보다는 carotenoid가 비교적 안정하였다. 색소의 안정도는 열처리온도와 시간에 따라 다르나 chlorophyll과 carotenoid는 $60^{\circ}C$, 90분 ; $80^{\circ}C$, 60분 ; $100^{\circ}C$, 10분 ; $150^{\circ}C$, 5분 ; $200^{\circ}C$, 3분 정도의 열처리 하에서는 $90\%$ 이상의 잔존율을 보였다. Hunter color 값은 열처리 정도에 따라 L 및 a 값의 증가, b값의 감소가 뚜렷하였다. 지방산은 위에 적은 정도의 열처리조건에서는 크게 영향을 받지 않고 안정하였다. 2. 배소김의 저장중에는 열처리에 의한 안정화효과, 조미액의 항산화성, 살포한 기름의 보호역활동에 의하여 chlorophyll a, carotene지 등은 안정화 하였고 지방산은 조미배소김의 경우 $\alpha_w0.2$, 50일이상 저장한후에도 극히 안정함을 보였으나 기름살포 배소김의 장기 저장에서는 지질의 열화를 가져왔다. 3. 유리아미노산에 있어서는 열화처리중에 Thr, Gly 등은 $80\%$ 이상의 손실을 보였고 저장중에는 안정하여 기름살포김의 경우 $\alpha_w0.2$, 100일간 저장후 $80\%$ 이상이 잔존하였다. 그 중 Glu의 손실이 가장 심하였다. 기름의 살포는 유리아미노산의 안정화에 유효한 것으로 보였다.

• 수산경영론집
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• 제42권3호
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• pp.31-39
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• 2011

This paper attempts to extend such analysis to the rather more difficult problem of optimal management of transnational fish stocks jointly owned by two countries. Transboundary fish such as Mackerel creates an incentive to harvest fish before a competitor does and leads to over-exploitation. This tendency is especially poignant for transnational stocks since, in the absence of an enforceable, international agreement, there is little or no reason for either government or the fishing industry to promote resource conservation and economic efficiency. In the current paper I examine a game theoretic setting in which cooperative management can provide more benefits than noncooperative management. A dynamic model of Mackerel fishery is combined with Nash's theory of two countries cooperative games. A characteristic function game approach is applied to describe the sharing of the surplus benefits from cooperation and noncooperation. A bioeconomic model was used to compare the economic yield of the optimal strategies for two countries, under joint maximization of net benefits in joint ocean. The results suggest as follows. First, the threat points represent the net benefits for two countries in absence of cooperation. The net benefits to Korea and China in threat points are 2,000 billion won(${\pi}^0_{KO}$) and 1,130 billion won(${\pi}^0_{CH}$). Total benefits are 3,130 billion won. Second, if two countries cooperate one with another, they reach the solution payoffs such as Pareto efficient. The net benefits to Korea and China in Pareto efficient are 2,785 billion won(${\pi}^0_{KO}$) and 1,605 billion won(${\pi}^0_{CH}$) or total benefits of 4,390 billion won : a gain of 1,260 billion won. Third, the different price effects under the two scenarios show that total benefit rise as price increases.