• 제목/요약/키워드: skipjack

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Skipjack 구조에 대한 DC 및 LC의 안정성 증명 (Provable Security for the Skipjack-like Structure)

  • 성재철
    • 정보보호학회논문지
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    • 제10권1호
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    • pp.13-22
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    • 2000
  • 본 논문에서는 Skipjack의 변환규칙 A와 같은 반복적인 구조에 대한 차분 특성 및 선형 근사식의 확률의 상한 값을 제시하고 이를 증명한다. 즉 라운드 함수에 대한 확률의 최대 값이 p이면 15라운드 후에 p4이 됨을 보인다. 따라서 본 논문에서 고려한 구조는 현재까지 DC 및 LC에 대한 안전성을 증명할 수 있는 구조인 Feistel 구조 및 MISTY 구조와 더불어 블록 암호의 설계 방법에 대한 다양성을 제공한다.

국제 유가 변동과 원양선망어업 가다랑어 가격 간의 인과성 분석 (An analysis of the causality between international oil price and skipjack tuna price)

  • 조헌주;김도훈;김두남;이성일;이미경
    • 수산해양기술연구
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    • 제55권3호
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    • pp.264-272
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    • 2019
  • The aim of this study is to analyze the relationship between international oil price as a fuel cost in overseas fisheries and skipjack tuna price as a part of main products in overseas fisheries using monthly time series data from 2008 to 2017. The study also tried to analyze the change of fishing profits by fuel cost. For a time series analysis, this study conducted both the unit-root test for stability of data and the Johansen cointegration test for long-term equilibrium relations among variables. In addition, it used not only the Granger causality test to examine interactions among variables, but also the Vector Auto Regressive (VAR) model to estimate statistical impacts among variables used in the model. Results of this study are as follows. First, each data on variables was not found to be stationary from the ADF unit-root test and long-term equilibrium relations among variables were not found from a Johansen cointegration test. Second, the Granger causality test showed that the international oil prices would directly cause changes in skipjack tuna prices. Third, the VAR model indicated that the posterior t-2 period change of international oil price would have an statistically significant effect on changes of skipjack tuna prices. Finally, fishing profits from skipjack would be decreased by 0.06% if the fuel cost increases by 1%.

Lipidomic profiling of Skipjack tuna (Katsuwonus pelamis) by ultrahigh-performance liquid chromatography coupled to high resolution mass spectrometry

  • Hu, Lingping;Hu, Zhiheng;Chin, Yaoxian;Yu, Haixia;Xu, Jianhong;Zhou, Jianwei;Liu, Donghong;Kang, Mengli;Hu, Yaqin
    • Fisheries and Aquatic Sciences
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    • 제25권3호
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    • pp.140-150
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    • 2022
  • A method of ultrahigh performance liquid chromatography coupled to high resolution mass spectrometry (UPLC-HRMS) was established for characterization of the lipid profile of Skipjack tuna. Over 300 lipid molecular species were identified through cross-acquisition in both positive and negative ion mode. Phospholipids (PLs) were dominant in Skipjack tuna. Lysophosphatidylethanolamine (LPE), phosphatidylethanolamine (PE), lysophosphatidylcholine (LPC) and phosphatidylcholine (PC) were the main lipid molecular species in PLs, accounting for 89.24% of the total PLs. The ratio of sphingolipids (SLs) and glycerolipids (GLs) were considerable, accounting for 12.30% and 13.60% of the total lipids respectively. Ceramide (Cer) was the main lipid molecular species of SLs, accounting for 64.96% of total SLs, followed by sphingomyelin (SM), accounting for 25.45% of total SLs. Ether diglycerides (ether DG) were the main lipid molecular species of GLs (97.83%). The main fatty acids (FAs) are unsaturated fatty acids (UFAs) in Skipjack tuna. Besides, a new FAs class branched fatty acid esters of hydroxy fatty acids (FAHFA) was detected, together with the FA. The active lipids identified in this study can be used to evaluate the nutritional value of Skipjack tuna.

濠洲 Cronulla 近海에 있어서 가다랭이의 먹이생物과 浮游생物의 組成과의 關係硏究 (Relationship between the Composition of Food Organisms of Skipjack Tuna Katsuwonus pelamis and Plankton in the Waters Adjacent tl Cronulla, New South Wales, Australia)

  • 박주석
    • 한국해양학회지
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    • 제19권1호
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    • pp.1-10
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    • 1984
  • 1975年 12月에서 1976年 5月 사이에 濠洲 Cronulla近海에서 實施한 가다랭이 漁業試驗時 採集한 浮游生物과 가다랭이 胃內容物의 造成 및 量的 相互關係性을 分析硏究 하였다. 가다랭이의 먹이생물의 造成과 豊度는 富裕生物의 그것들과 잘 一致하였으며 그 主要먹이 생물로서는 Nyctiphanes australis, brachyura幼生, 정어리種漁 및 Copepoda등임을 밝혔다. 가장 많은 가다랭이 漁獲은 富裕生物組成上 N. australis와 brachyura유생이 가장 豊富했던 1月과 2月에 있었다. 特히 Copepoda중의 Undinula vulgaris는 가다랭이의 먹이생물中 선택적 기호성먹이로서 가치가 큰 것으로 나타났다.

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Food Component Characteristics of Tuna Livers

  • Kang, Kyung-Tae;Heu, Min-Soo;Jee, Seung-Joon;Lee, Jae-Hyoung;Kim, Hye-Suk;Kim, Jin-Soo
    • Food Science and Biotechnology
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    • 제16권3호
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    • pp.367-373
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    • 2007
  • Livers of skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares) were investigated on the food compositional characteristics and also compared to that of Alaska pollack (Theragra chalcogramma). The proximate compositions of skipjack tuna and yellowfin tuna livers were high in crude protein, carbohydrate, and crude ash, while were low in crude lipid when compared to that of Alaska pollack liver. The results of heavy metal suggested that tuna livers appeared safe as a food resource. The total amino acid contents of skipjack tuna and yellowfin tuna livers were 17.7 and 17.1 g/100 g, respectively, and the major amino acids in both livers were aspartic acid, glutamic acid, alanine, valine, leucine, and lysine. Tuna livers were good sources of iron and zinc, while have low lipid content. The extractive nitrogen contents of skipjack tuna and yellowfin tuna livers were 526.5 and 468.2 mg/100 g, respectively, and their major free amino acids were taurine, glutamic acid, and alanine. From the results of taste value, the major taste active compounds among free amino acids were glutamic acid and aspartic acid.

어류 프레임 농축액과 시판 사골 농축액의 위생적 및 영양적 특성 비교 (Comparison on Sanitary and Nutritional Characteristics Between Skipjack Tuna Ktsuwonus pelamis Frame and Commercial Beef Bone Extract Concentrates)

  • 임치원;성상욱;허민수;이태기;김진수
    • 한국수산과학회지
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    • 제50권5호
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    • pp.467-472
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    • 2017
  • There is increasing interest in developing flavor-enriched concentrate using byproducts of skipjack tuna Ktsuwonus pelamis as a replacement for commercial beef bone extract concentrate (CBB-EC). This study was compared on sanitary and nutritional characteristics between skipjack tuna frame extract concentrate (ST-EC) and CBB-EC as a control of skipjack tuna frame extract concentrate. The moisture contents of CBB-EC and ST-EC 41.4-4.9% and 45.3%, respectively. The results of viable cell counts and E. coli assays suggested that CBB-EC and ST-EC is a safe and sanitary for use in food. There were no differences in peroxide values among CBB-ECs. The total amino acid contents in CBB-EC and ST-EC were 25.6-29.3 g/100 g and 37.9 g/100 g, respectively, and the major amino acids present glutamic acid, proline, glycine, alanine and arginine. Regardless of kinds of the mineral, mineral contents of ST-EC higher than those of CBB-EC. The major fatty acids were 16:0, 18:0 and 18:1n-9 in CBB-EC, 16:0, 18:1n-9 and 22:6n-3 in ST-EC. These results can be used as background information to develop flavor-enriched concentrates from byproducts of skipjack tuna as replacement for CBB-EC.

가다랭이 안와조직으로부터 DHA의 추출 및 정제 (Isolation and Purification of DHA from Skipjack Orbital Tissue Oil)

  • 정보영
    • 한국수산과학회지
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    • 제26권6호
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    • pp.529-537
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    • 1993
  • 가다랭이 안와유로부터 docosahexaenoic acid(DHA)를 정제하기 위해 기존의 방법들을 적용하여 비교 검토하고, DHA의 효과적인 정제를 위해 조작방법을 개량하였다. 가다랭이 안와조직의 총지질은 $55.4\%$였으며, 이 중 DHA는 $23.7\%$였다. 저온분별결정법과 요소결정법을 적용한 결과 순도에서 각각 약 $46\%$$61\%$의 DHA가 얻어졌다. 이들 방법들은 순도면에서는 다소 떨어지나, 정제조작이 단순하여 다량의 DHA 분리에 적합하였다. 질산은 수용액법은 상기 2가지 방법에 비하여 순도면에서는 약간 개선되었으나, 회수율이 대단히 낮았다($10\%$ 이하). 질산은 함침 실리카 칼럼 크로마토그래피법은 고순도 DHA의 정제방법으로써 적합하였다(순도 $98\%$ 이상, 회수율 $90\%$ 이상). 결과적으로 저온분별결정법과 질산은 함침 실리카 칼럼 크로마토그래피법을 조합한 개량법(2단계 정제법)이 가다랭이 안와유로부터 고순도 DHA($99.9\%$)의 정제를 위한 가장 효과적인 방법으로 평가되었다.

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Partial Replacement of Fish Meal by Fermented Skipjack Tuna Viscera in Juvenile Olive Flounder (Paralichthys olivaceus) Diets

  • Lee, Sang-Min;Pham, Minh Anh;Shin, Il-Shik
    • Fisheries and Aquatic Sciences
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    • 제12권4호
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    • pp.305-310
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    • 2009
  • This study was carried out to evaluate the use of fermented skipjack tuna viscera (FSTV) as an alternative for fish meal in juvenile olive flounder (Paralichthys olivaceus) diets. Lactobacillus bulgaricus was used as a starter for fermentation of skipjack tuna viscera. Four isonitrogenous (49% crude protein) and isocaloric (4 kcal/g DM) diets were formulated to contain graded levels (0, 5, 10, and 15%) of FSTV. Each experimental diet was fed three replicate groups (40 fish per tank) of juvenile flounder (average weight, $3.3\pm0.2$ g) for 5 weeks. At the end of feeding experiment, inclusion of FSTV up to 15% in diets did not affect survival rate (%) and weight gain of fish. Feed efficiency, protein efficiency ratio, protein and lipid retentions of fish fed the diet containing 10% FSTV were higher than those of fish fed the control diet (P<0.05). The values of fish fed the diet containing 15% FSTV were not different from those of fish fed other diets. Whole body lipid content of fish fed the diet containing 10% FSTV was higher than that of fish fed the diet containing 15% FSTV and control diet. The present results indicate that fermented skipjack tuna viscera could partially replace fish meal in juvenile flounder feed, and the inclusion of 10% FSTV may be efficient in improving the feed utilization of fish.

중서부태평양 수역 우리나라 다랑어 선망어업의 시간대별 어획률 비교 (Comparison of catch rate by operation time of Korean tuna purse seine fishery in the Western and Central Pacific Ocean)

  • 하영신;권유정;이미경;이성일
    • 수산해양기술연구
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    • 제58권4호
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    • pp.317-325
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    • 2022
  • Korean tuna purse seine fishery in the Western and Central Pacific Ocean (WCPO) began to operate in earnest in the early 1980s. Since then, the total catch has shown an increasing trend and the target species are skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacare) and bigeye tuna (Thunnus obesus). Based on the operational data of Korean tuna purse seine fishery from 2016 to 2020, the catch rates of target species (skipjack and yellowfin tunas) were analyzed by operation time for set types (free school and FAD sets). In the case of the free school sets, they were usually made from sunrise to sunset, and the catch rate was high before and after sunrise for skipjack tuna and before sunset for yellowfin tuna. On the other hand, for the FAD sets, more than 90% of them were made just before sunrise, and there were few operations during the daytime. The purpose of this study is to examine whether there are differences in the catch rate of skipjack and yellowfin tunas by operation time and by school type for Korean tuna purse seine fishery in the WCPO, which could be helpful in understanding its fishing characteristics and providing useful information for developing the stock indices of the target species.