• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.769-781
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• 2021

Given data about the annual fishery yield of the common squid Todarodes pacificus, and the catch-per-unit-effort (CPUE) data from multiple fisheries from 2000-2018, we applied a Bayesian state - space assessment model for the squid population. One of our objectives was to do a stock assessment, simultaneously incorporating CPUE data from the following three fisheries, (i) large trawl, (ii) jigger, and (iii) large purse seine, which comprised on average a year about 65% of all fisheries, allowing possible correlations to be reflected. Other objectives were to consider both observation and process errors and to apply objective priors of parameters. The estimated annual exploitable biomass was in the range of 3.50×10⁵ to 1.22×10⁶ MT, the estimated intrinsic growth rate was 1.02, and the estimated carrying capacity was 1,151,259 MT. Comparison with available results from stock assessment of independently analyzed single fisheries revealed a large difference from the estimated values, suggesting that stock assessment based on multiple fisheries should be performed.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.133-136
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• 2017

Fermentation plays a vital role in the nutritional enrichment of food. Korea has a long tradition of adding fermented food to the daily diet and jeotgal is one of the common fermented and salted foods in Korean cuisine. In our study, we added soymilk as an additive to squid jeotgal to improve its functionality. We mixed different concentrations of soymilk (2, 5, and 10 mg/g) with squid jeotgal samples, fermented them for one week, and then tested their antioxidant and anticancer activities to compare with those of squid jeotgal samples without soymilk additive. To investigate the anticancer characteristics, glutathione-S-transferase (GST)-pi enzyme assay was used. To test the antioxidant activities, various assays were performed, including 2,2-diphenyl-1-picryl hydrazyl free radical scavenging activity, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium saltradical cation scavenging assay, and reducing power assay. Samples fermented with a small amount of soymilk showed excellent anticancer activity. The addition of only 2 mg/g of soymilk to squid jeotgal inhibited the activity of GST-pi by almost 50% when compared with the sample with no addition. Moreover, no undesirable bitterness or astringency was noticed. Our results could help to improve the current food status of squid jeotgal and it could be used to reduce the risk of chronic disease along with its basic nutritional function.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.2
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• pp.175-179
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• 1990

Investigations of skin stripping freezing and thawing conditions of common-European squid (Loigo vulgaris) were carried out. The most effective method of skin stripping was to immerse the sample at 5$0^{\circ}C$ for 10-15 minutes in fresh water or salt solution(5-10% w/v) Contact freezing and fresh water thawing method was found to be effective. The muscle structure of the sample thawed after contact freezing was almost the sample after contact freezing was almost the same as that of raw sample.

• Progress in Superconductivity
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• v.4 no.1
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• pp.42-47
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• 2002

Measuring magnetic fields with a SQUID sensor always requires preliminary adjustments such as optimum bas current determination and flux-locking point search. A conventional magnetoencephalography (MEG) system consists of several dozens of sensors and we should condition each sensor one by one for an experiment. This timeconsuming job is not only cumbersome but also impractical for the common use in hospital. We had developed a serial port communication protocol between SQUID sensor controllers and a personal computer in order to control the sensors. However, theserial-bus-based control is too slow for adjusting all the sensors with a sufficient accuracy in a reasonable time. In this work, we introduce programmatic control sequence that saves the number of the control pulse arrays. The sequence separates into two stages. The first stage is a function for searching flux-locking points of the sensors and the other stage is for determining the optimum bias current that operates a sensor in a minimum noise level Generally, the optimum bias current for a SQUID sensor depends on the manufactured structure, so that it will not easily change about. Therefore, we can reduce the time for the optimum bias current determination by using the saved values that have been measured once by the second stage sequence. Applying the first stage sequence to a practical use, it has taken about 2-3 minutes to perform the flux-locking for our 37-channel SQUID magnetometer system.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.3
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• pp.215-222
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• 2014

Paralarvae of the common squid, Todarodes pacificus Steenstrup were sampled with the bongo net (diameter: 60 cm, mesh: $333{\mu}m$) by using oblique tow method with the oceanographic research vessel (Tamgu 12) at 21 stations along the southwestern coastal waters of the East Sea in August and September, 2013. Paralarvae were collected 16 ind./$10m^3$ in August and 7 ind./$10m^3$ in September at approximately, and bottom depth was from 70 m to 500 m. Mantle length of paralarvae was from 1.7 to 6.0 mm. Paralavae were distributed mainly in offshore stations in August and near by Cape Janggi in September. Optimum embryo survival temperature ($18-24^{\circ}C$) was formed shallower than 35 m depth for almost stations where paralarvae were existed, and survival temperature ($15-24^{\circ}C$) for embryo stage was located shallower than 75 m.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.183-188
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• 2022

It is a difficult task to estimate parameters in even a simple stock assessment model such as a surplus production model, using only data about temporal catch-per-unit-effort (CPUE) (or survey index) and fishery yields. Such difficulty is exacerbated when time-varying parameters are treated as random effects (aka state variables). To overcome the difficulty, previous studies incorporated somewhat subjective assumptions (e.g., B₁=K) or informative priors of parameters. A key is how to build an objective joint prior of parameters, reducing subjectivity. Given the limited data on temporal CPUEs and fishery yields from 1999-2020 for common squid Todarodes pacificus, we built a joint prior of only two parameters, intrinsic growth rate (r) and carrying capacity (K), based on the resilience level of the population (Froese et al., 2017), and used a Bayesian state-space production assessment model. We used template model builder (TMB), a R package for implementing the assessment model, and estimating all parameters in the model. The predicted annual biomass was in the range of 0.76×10⁶ to 4.06×10⁶ MT, the estimated MSY was 0.13×10⁶ MT, the estimated r was 0.24, and the estimated K was 2.10×10⁶ MT.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.1052-1057
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• 2021

The diet composition of common flying squid Todarodes pacificus was studied using 1,084 specimens collected through trawl and jigging from June 2018 to June 2020 in the East Sea of Korea. The mantle length (ML) of the collected individuals ranged from 13.6 to 31.1 cm. Todarodes pacificus is a carnivore. In the study area, T. pacificus was observed feeding mainly on fish and cephalopods, in addition to small quantities of crustaceans. The calculated trophic level value for T. pacificus was 4.10. Small individuals (ML, <18.0 cm) mainly fed on cephalopods, while intermediate (ML, 18.0-23.0 cm) and large (ML, ≥23.0 cm) individuals fed mainly on fish and occasionally on cephalopods. Overall, as the body size of T. pacificus increased, the mean weight of the consumed prey increased (one-way ANOVA, P<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.856-861
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• 2013

The first occurrence of a giant squid, Architeuthis sp. (one specimen), and the oarfish, Regalecus russellii (two specimens) in the East Sea were reported based on specimens collected in January and February 2010. The giant squid (Architeuthis sp.) stranded at Pohang in Jan. 2010 was female, 175 cm in mantle length (ML), 506 cm in tentacle length (TL), and 33.9% FL/ML, it contained common squid beaks. Both stranded oarfish (Regalecus russellii) at Uljin (Jan. 2010) and Yeongdeok (Feb. 2010) were male, with total weigths (TW) of 18,506 and 21,703 g and total lengths (TL) of 3,850 and 3,670 mm, respectively. The stomach of the first was empty, while that of the second was filled with euphausiids. In the East Sea, giant squid have been stranded 14 times in five areas, while 17 oarfish have been stranded in nine areas. Since 1990, the two species have been found most often at Pohang.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.5
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• pp.367-375
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• 2006

The chemical components, lipid class, and fatty acid composition of muscle from male and female common squid, Todarodes pacificus, were examined to evaluate the potential utilization of muscle from fin, head, arms, and tentacles, which consumers usually like less than the mantle. The mantle was found to constitute 47-49% of the total muscle and the proportion was slightly higher in females than in males. For the remaining 51-53% of the muscle, the only gender difference was that the arms of males contained approximately 3% more muscle than those of females (P<0.05). The protein content was higher in the mantle, arms, and tentacles than in the fin and head in both males and females (P<0.05), and was slightly higher in males (15.7-20.7%) than in females (15.1-19.2%). By contrast, the lipid content was slightly higher in females (1.82-2.54%) than in males (1.01-2.37%), and the fins in both males and females contained the most lipids (2.37-2.54%) of all muscle. The prominent lipid classes in the muscles were free sterol (males 81.5-91.9% vs. females 84.9-91.8% for the non-polar lipid content), phosphatidylcholine (PC, males 59.3-62.4% vs. females 49.2-57.8% for the phospholipid content) and phosphatidylethanolamine (PE, males 22.0-28.8% vs. females 25.6-33.8% for the phospholipid content). The percentage of PC was approximately 5-10% higher in males (P<0.05), especially in the fin, while that of PE was approximately 3-5% higher in female (P<0.05), especially in the head. All of the squid muscle contained 52.1-54.9% of n-3 polyunsaturated fatty acids (PUFA), such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Males contained slightly more DHA, whereas female contained more EPA. The total percentage of n-3 PUFA differed little among muscles within the same gender.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1997.06a
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• pp.300-301
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• 1997