• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.4
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• pp.294-303
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• 2008

Squid jigging fishery is very important in that there are about 1,000 jigging vessels more than 10 tonnage and about 5,000 ones less than 10 tonnage in Korea. But the cost of oil which is used to light fishing lamps, goes significantly up to almost one hundred million won for 50 tonnage vessels and forty million won in case of vessels less than 10 tonnage. This cost has almost taken 40% of total fishing costs. That is, the fishing business condition of squid jigging fishery is recently in the very difficult situation. As oil price increases, the business condition of the fishery gets worse and worse. Therefore it is very urgent to develop an economical fishing lamp, to solve this problem of fishery's business difficulty. This research aims at developing a fishing lamp for squid jigging fishery using the light emitting diode which has very excellent efficiency and durability. We made a water tank with 20 meters width which is a shape of raceway to research behavioral characteristics of Japanese flying squid to LED light, and made an experiment to investigate optimum wave of LED light to lure squid. The method is to establish LED lamps on both ends of water tank and to observe squid's behavior. Colors and wave lengths of LED lamps, used in experiment, are red(634nm), yellow(596nm), green(523nm), blue(454nm) and white(454nm+560nm). In experiment for attractive capability of LED lamp to squids, Japanese flying squid are highly attracted to blue lamp and white lamp. However, they are dispersed to red and yellow lamps. In addition, Japanese flying squid have moved and stayed in both dark ends of water tank. When compared intermittent lamp with continuous lamp, Japanese flying squid are highly attracted to intermittent lamp when intermittent interval is 0.25 second.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.333-339
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• 2003

New manufacturing process was applied to manufacture the low salted Squid-Jeotgal to improve the quality variation salty taste and shelf-life. It's optimum salting and sugaring process was made by the addition of $17\%$ NaCl for 3 hr and $15\%$ corn syrup for 4 hr with 10 rpm agitation. Quality variations of Squid-Jeotgal produced by the improved and the conventional process were packed by jar, polyethylene lerephthalatefpolyethyleneilinear low density polyethylene (PET) and low density polyethylene (PE). And then quality variations of them were investigated at storage temperature of 10, 20, and $30^{\circ}C.$ Decreasing rate of pH, increasing rates of VBN and viable cell counts of Squid-Jeotgal produced by the improved process were slower than those of the conventional process at all storage temperature. Sensory evaluation indicated that the production of Squid-Jeotgal by the improved process extended the shelf-life about 10-20 days.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.3
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• pp.176-181
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• 2008

To evaluate the effective use of endoprotease from squid viscera as a food processing aid, various methods of fractionating endoprotease from viscera of the Argentina shortfin squid (Illex argentinus) were evaluated. The endoprotease-positive fractions of each fractionation were fraction II (30-40%, w/w) with cold acetone, fraction IV (50-60% saturation) with ammonium sulfate, fraction UF with anion exchange chromatography, and fraction II (15-24 kDa) with gel filtration. The specific activities (approximately 25 U/mg) of the fractions using ammonium sulfate and gel filtration were higher than the others. Total azocaseinolytic activity and recovery of the positive fraction using gel filtration were 806.95U and 37.82%, respectively, and were the highest among the positive fractions. Based on the results, gel filtration was the most efficient method for fractionating endoprotease from the viscera of Illex argentinus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1051-1057
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• 1999

The effects of gamma irradiation on taste compounds of low salted and fermented squid were investig ated. Salted and fermented squid products were prepared with salt concentrations of 5%, 10%, and 20% and was fermented at 15oC and 25oC after gamma irradiation with a dosage of 2.5~10 kGy. Amino nitrogen (AN), volatile basic nitrogen(VBN), trimethylamine(TMA), and hypoxanthine(Hx) contents were examined during the fermentation periods. Results showed that gamma irradiation had no effect on the initial con tents of AN, VBN, TMA, and Hx compared with non irradiated salted and fermented squid. During the fermentation periods, these contents rapidly increased in accordance with the decrease in NaCl concen tration and irradiation dose, and the increase in fermentation temperature. Specifically, the taste compounds of salted and fermented squid prepared with a NaCl concentration of 10% and an irradiation dose of 10 kGy maintained the appropriate level for the fermentation period at 15oC.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.227-237
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• 2013

In Jeju Island, red sea bream is mainly caught by long line with a live squid as bait. The movements of artificial jigs in the fishery are supposed to be an important factor for catching the target organism as well as bait. To develop new fishing method for long line fishery, movements of the bait which was squid were tried to be characterized. In a water tank experiment, a live squid was hooked by a fish hook attached to a model long line. And then movements of squids in the water tank were recorded for 20 minutes by a video camera. Recorded movement of the squid was just periodically up-and-down moving, with a dominant frequency of 0.125Hz, and amplitude of 10.8cm.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.3
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• pp.220-227
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• 1995

An underwater speaker was designed and used as sound source for thronging shoal of squid in squid angling gear operation. The frequency characteristics of the designed speaker was analyzed experimentally and the thronging response of shoals of squid which may be a key parameter for a new sound catching method, was characterized in audible frequency. The field experiment was carried out in the coast of Cheju Island. The results of this study are summarized as follows; 1. Amplitude response of the speaker shows a maximum in their the frequency of 500Hz. 2. The output waveform distortion is not measured in the frequency range of 250~600Hz. 3. A underwater noise of shoals of squid which were thronged by fish lamp in night appeared the center frequency of 300~400Hz. 4. The shoals of squid shows a thronging response, when a manufactured underwater speaker transmits a intermittent audible sound of 300~400Hz in 10m depth of water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.437-442
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• 2022

Squid jeotgal is a very popular traditional, salted, and fermented seafood in Korea. Due to the development of a distribution structure, a lot of imported squid jeotgal has recently entered Korea. In this study, we analyzed and compared the microbial contamination levels of domestic and imported squid jeotgal. The total viable bacterial count in domestic and imported jeotgal was 5.20 and 5.38 log CFU/g, respectively. The highest contamination level was 6.94 log CFU/g in one of the imported squid jeotgal samples. Coliforms were not detected in domestic jeotgal but were detected at 50% with 2.21 log CFU/g in imported jeotgal. Escherichia coli and Staphylococcus aureus were not detected (ND: <1 log CFU/g) in both domestic and imported jeotgal. All samples of jeotgal were negative for Bacillus cereus and Clostridium perfringens. The microbial contamination levels determined in the current study may be utilized as primary data to execute microbial risk assessments on domestic and (or) imported jeotgal.

• Progress in Superconductivity
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• v.4 no.2
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• pp.121-126
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• 2003

The single layer direct-coupled YBCO SQUID magnetometers have been fabricated and characterized for the purpose of the measurement of weak magnetic signals in unshielded environment. Two types of magnetometers have been designed and fabricated using 10 mm$\times$ 10 mm substrates. We could operate the conventional 3-mm-wide solid pickup loop magnetometers more stably than the 12-parallel-line pickup loop magnetometers in laboratory environment. We developed a first-order electronic gradiometer system using the SQUID sensors with axial displacement of 80 mm without any mechanical alignment of magnetometers. The system with a software filter using calculation of discrete Fourier transform could record clearly weak pulse signal of 100 pT in a magnetically disturbed environment.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.161-164
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• 1999

We have fabricated the direct-coupled planar type 1st-order SQUID gradiometers. The gradiometer consists of moats or slots in SQUID loop. It is made by YBa$_2Cu_3O_7$ thin films using pulsed laser deposition method on SrTiO$_3$ single crystal and bi-crystal substrates. We have studied the effects of slots and moats in SQUID loop by measuring the voltage modulation signals under uniform field and 1st-order gradient, and the noise properties under non-shielded environment.

• Progress in Superconductivity
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• v.3 no.2
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• pp.159-162
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• 2002

We have detected cracks inside multi-layer metal sheets with nondestructive evaluation system consisting of SQUID gradiometer. Double D-shape coil was carefully designed with computer simulation for spatial distribution of magnetic field. It was aligned and placed in between SQUID and metal sheets in order to reduce the field effect to SQUID and to maximize eddy current in the sheets. The metal plate in bottom of the metal stack contained artificial cracks which were scanned by an X-Y scanning system. The information of crack position and size could be estimated by analysis of SQUID signal. Details of the results will be discussed .