• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.3
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• pp.236-245
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• 2021

In this study, a drifting test using a experimental vessel (2,966 tons) in the northern waters of Jeju was carried out for the first time in order to obtain the fundamental data for drift. During the test, it was shown that the average leeway speed and direction by GPS position were 0.362 m/s and 155.54° respectively and the leeway rate for wind speed was 8.80%. The analysis of linear regression modes about leeway speed and direction of the experimental vessel indicated that wind or current (i.e. explanatory variable) had a greater influence upon response variable (e.g. leeway speed or direction) with the speed of the wind and current rather than their directions. On the other hand, the result of multiple regression model analysis was able to predict that the direction was negative, and it was demonstrated that predicted values of leeway speed and direction using an experimental vessel is to be more influential by current than wind while the leeway speed through variance and covariance was positive. In terms of the leeway direction of the experimental vessel, the same result of the leeway speed appeared except for a possibility of the existence of multi-collinearity. Then, it can be interpreted that the explanatory variables were less descriptive in the predicted values of the leeway direction. As a result, the prediction of leeway speed and direction can be demonstrated as following equations. Ŷ₁= 0.4031-0.0032X₁+0.0631X₂-0.0010X₃+0.4110X₄ Ŷ₂= 0.4031-0.6662X₁+27.1955X₂-0.6787X₃-420.4833X₄ However, many drift tests using actual vessels and various drifting objects will provide reasonable estimations, so that they can help search and rescue fishing gears as well.

• Journal of the Korean GEO-environmental Society
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• v.12 no.1
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• pp.61-70
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• 2011

The impact protection system consists of an arrangement of circular sheet pile cofferdams-denoted dolphin structuredeeply embedded in the seabed, filled with crushed rock and closed at the top with a robust concrete cap. Centrifuge model tests were performed to investigation the behaviors of dolphins in this study. Total 7 quasi-model tests and 11 dynamic model tests were performed. The main experimental results can be summarized as follows. Firstly, The experimental force-displacement results for quasi-static tests show a limited influence on the initial stiffness of the structure from the change in fill density and the related change in the stiffness of the fill. And by comparing the dissipation at the same dolphin displacement it was found that the denser fill increase the dissipation by 16% for the 20m dolphin and by 23% for the 30m dolphin. The larger sensitivity for the large dolphin is explained by a larger contribution to the dissipation from strain in the fill. In low level impacts the dynamic force-response is up to 26~58% larger than the quasi-static and the dissipation response is showed larger in small displacement. Hence, it is concluded conservative to use the quasi-static response characteristics in the approximation of the response, and it is further concluded that the dolphin resistance to low level impacts is demonstrated to be equivalent and even superior to the high level impacts.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.632-638
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• 2022

As Korean coastal activity is high, the incidence of accidents caused by marine waste is extensive. An accident in which marine floating waste ropes and fishing nets are wound around the propeller of a sailing ship is termed "Rope wrapped accident." To prevent such accidents, this study applied the Finite Element Method (F.E.M.) for performance evaluation of the shaver type cutter, commercialized in Korea, through a structural safety review and water tank test. The results demonstrate that all parts constituting the rope cutter were damaged before reaching 0.5s, and the safety factor of each part was found to be at least 2 based on the maximum stress generated compared to the tensile strength. In the basin test, the cutting process of the shaver type rope cutter was reviewed, and the installation angle was set for each case considering that the rope floating in the sea actually enters at various angles. Consequently, as it was successful at cutting in all the cases, it can be concluded that there will be no problem in cutting the rope regardless of the mounted angle of the cutting blade.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.594-600
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• 2022

When a large liquefied natural gas (LNG) carrier is anchored at a coastal terminal, calculations on mooring forces of mooring cables induced by environmental loads such as strong winds and currents are needed to secure mooring safety. The advantages and disadvantages of several existing mooring force calculation methods are compared and analyzed with their application conditions. Resultingly, mooring equipment guidelines of the Oil Companies International Marine Forum (OCIMF) are chosen as the computational method for this study. In this paper, the mooring forces of a large LNG carrier with spectrum was calculated using the OCIMF mooring equipment guidelines. The calculation shows similar maximum forces resulted from the calculation using experiment data of a wind tunnel test. To verify the results, OPTIMOOR, a dedicated mooring force calculation software, is used to calculate the same mooring conditions. The results of both calculations show that the computational method recommended by OCIMF is safe and reliable. OPTIMOOR calculates more detailed tensile force of each mooring cable. Thus, the calculation on mooring forces of mooring cables of a large LNG carrier using OCIMF mooring equipment guidelines is verified as an applicable and safe method.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.554-562
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• 2022

Humans technological advancements have resulted in the depletion of whale resources. Accordingly, the International Whaling Commission was established to preserve whale resources and ensure the orderly development of the whaling industry. After a commercial whaling moratorium came into effect, the international trade of whale meat and related products was banned. However, There is a systematic activity through illegal remodeling ships because whales incidentally caught may be distributed in Korea and have a significant economic benefit. Although suspected illegal whaling is actively cracked down, but it is still insufficient to prevent illegal whaling and distribution. To prevent this, stereoscopic crackdowns utilizing air forces and patrol ships are effective, and it is necessary to quickly separate the captured ship and crew to prevent the destruction of evidence. For the transparent distribution of whale meat, it is necessary to advance related technologies such as whale species identification and individual identification of forensic science institutions based on whale DNA database of the National Institute of Fisheries Science. Accordingly, the Korea Coast Guard Research Center is directly conducting research on related national R&D project. To increase the efficiency of identifying whale-related evidence at crime scene, a rapid test kit that responds specifically to whale bloodstrains is developing and evidence transport packs are manufacturing and distributing, while identification technologies are also being advanced.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.127-128
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• 2021

This study suggests surface wave communication, which uses a metal surface as a medium, to provide wireless communication in the extreme environment due to surrounding metal materials on vessels. The test was conducted on a G/T 265 tons tug boat, and to confirm the possibility of surface wave communication between a bridge and each designated space in the boat. As a result, the transmission speed was 13Mbps in average. For the test case between the bridge and the engine room, transmission speed was 4.3Mbps while the engine was on, and 1.2Mbps during sailing. It was able to be overcome by partially changing the equipment installation location. Surface wave communication in a bow storage, a fully enclosed space, had 8Mbps better transmission speed than wireless communication; this confirmed the superiority of surface wave communication in confined spaces on a vessel. Additional surface wave generators were designed and applied to resolve the paint issue. It is expected to apply surface wave communication to implement the new wireless solution on vessels.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.672-680
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• 2023

Weight is a critical factor in the ship design process given that it has a substantial impact on the hydrodynamic performance of ships. Typically, ships are optimally designed for specific conditions with a fixed draft and displacement. However, in reality, weight and draft can vary within a certain range owing to operational activities, such as fuel consumption, ballast adjustments, and loading conditions . Therefore, we investigated how resistance changes under three different loading conditions, namely overload, design-load, and lightship, for small craft, using both model experiments and numerical simulations. Additionally, we examined the sensitivity of weight changes to resistance to enhance the performance of ships, ultimately reducing power requirements in support of the International Maritime Organization's (IMO) goal of reducing CO2 emissions by 50% by 2050. We found that weight changes have a more significant impact at low Froude Numbers. Operating under overload conditions, which correspond to a 5% increase in draft and an 11.1% increase in displacement, can lead to a relatively substantial increase in total resistance, up to 15.97% and 14.31% in towing tests and CFD simulations, respectively.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.977-983
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• 2002

This study was performed to establish the precise and rapid method to distinguish croakers through the pigment analysis of colored imported white croakers for adultration. We surveyed the coloring behaviors, extraction test by water and organic solvent and using pigments such as targeting, curcumine, and azo dye products. The pigment of yellow croaker is not stained on wet cloth or tissue which is rubbed on epidermis of yellow croaker and was not eluted in water extraction test, while adulterated pigments were easily extracted by water and acetone, but edible diluted yellow, Yellow No. 4 and Yellow No. 5 were not extracted. Reactive pigment was detected easily by extraction with water and dispersed pigment was also detected by extraction test. As a result of discoloring characteristics of carotene having similar structure to yellow croaker and azo dye by oxidation and reduction, azo dyes were not discolored by oxidation with sodium percarbonate or peracetic acid but that were discolored by oxidation with Fenton reagent after 1hr and by hypochlorite promptly. On the other hand, carotenes were not discolored by sodium precarbonate and Fenton reagent but discolored by sodium hypochlorite after 2 hr and by peracetic acid promptly. Azo dyes were discolored by reduction with sodium hydrosulfite and sodium carbonate but carotenes were not discolored by these reagents. This discoloring test was applicable to detect adulterated pigments and other marine product.

• Clinical and Experimental Reproductive Medicine
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• v.18 no.2
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• pp.133-142
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• 1991

This study was carried out to observe the change in uterine cyclic nucleotide level and the effect of PAF on cyclic nucleotides in uterine tissue in early pregnany in order to understand reciprocal relation ship between PAF and cyclic nucleotides in pregnancy in the rat. The test groups were injected intramuscularly with $1{\mu}g$ of PAF or 1.25mg of BN-52021 on day 0, 1, 2, 3, 4 and 5 of pregnancy. The level of cyclic nucleotide in removed uterine tissue was assayed by using cyclic nucleotides test kits. The results showed that the cyclic AMP content in uterine tissue of non-pregnant at pro-oestrus rat was $2.91{\pm}0.33$ pmol/mg protein which was lower than those of pregnant rat. The cyclic GMP content in uterine tissue of non-pregnant rat was $0.39{\pm}0.20$ pmol/mg pro-tein which was also lower than those of pregnant rats. The maximum level in cAMP was $5.92{\pm}1.72$ pmol/mg protein on day 3 and cGMP, $1.03{\pm}0.22$ pmol/mg protein on day 4. On each day of pregnancy, PAF induced the increased cAMP level ompared with that of intact rat. That was significant on day 0, 2 and 4 of pregnancy, p<0.05, on the other hand PAF receptor antagonist, BN-52021 ecreased cAMP level in uterine tisssue. PAF as well as BN-52021 had not an consistent effect on changes in cGMP level. These results suggest that cyclic nucleotide levels in uterine tissue ware increased during early pregnancy and PAF influences cAMP level in uterine rather than cGMP level during peri-implantation period, accordingly demonstrating a possible involvement of PAF in the regulation of implantation-related events through cAMP-mediated process.

• Journal of the Korean Society of Costume
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• v.22
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• pp.135-158
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• 1994

The fashion industry of today is closely re-lated with the information activity. This study investigates now they take advantage of the fashion information by analysing some related fields including fashion design. Furthormore this study identify the factor which makes the design activity distinctive and predict and fu-ture trend in design. The purposes of this study through analysis are : to help find the way to facilitate the fashion industry and to develop the fashion merchandising in order to activate the re-cession of manufacturers and to improve competitiveness in the world market and to contribute to the academic achievement in the study of fashion merchandising. In the experimental approach the tasks of research are as follows: Research 1: The application of fashion infor-mation is discussed in terms of process and level. Research 2: The differences of the fashion design activities are captured on the basis of the characteristics of manufactures and fashion specialists and fashion information ac-tivities. The factors are identified which pre-dict and discriminate the results of fashion de-sign activities. The questionaire and interview were conduc-ted among women's clothing manufactures in Seoul and their fashion specialists in charge of merchandise development. The methods of survey were designed on the basis of theories developed so far and on he advice from the social scientists and fashion specialists. the methods were corrected and complemented through the 1st and 2nd preliminary investigations before their application For data analysis cronbach's a coefficient fre-quency percentage average standard devi-ation pearson's correlation coefficient were calculated and t-test F-test(ANOVA) Duncan's multiple range test regression and Discriminant analysis were conducted. The results of analysis throughout the experimen-tal studies were as follows: 1. The analysis of fashion in formation (1) the present application of information a. The source of information : Both the foreign and the domestic information came mostly from fashion journals magazines newspapers and other periodicals, the main source of market information was collected from the survey of popular items in recent years the data about the life-style of customers and their tastes for wearing were widely used as the information about consumers. b. The applicaton of information : The most widely used information was about fabrics. The foreign information was prefered on the whole. The domestic problems pointed out in this investgation were that the domestic journals showed the lack of specialty and the special organizations for fashion informatino were in urgent need. (2) The research of fashion information a. The various processes and levels of in-formation activities: Among the process of collection analysis and distribution the collec-tion process showed a good acheivement whereas the distribution whereas the distribution didn't. In levels of the systematic activities the acceptance of support and the utility of supported instruments the first indicated a high degree whereas the second showed lowest. b. The correlationship among subvariables : There was a significant correlation between the collection and the analysis process. The systematic activities revealed close relation-ship with the analysis process and the accept-ance of support with the distribution process. The close correlation was found between the utility of supported instruments and the analy-sis process. 2. The analysis of the fashion design activities (1) No significant differences were found in the design activities when the characteristics of companies were compared only. (2) According to the characteristics of fashion specialists the one with age experi-ence and high income showed rather good achievement but no significant differences were captured among sex department in charge title academic background education in abroad and field experience (3) The fashion information activities were strongly correlated with the design achieve-ment : The analysis process and the system-atic activity level had a great influence on the design activities. (4) In order to examine which cha-racteristics in (1-3) made it possible to pre-dct and discriminate the achievement in de-sign activities the Discriminant analysis was carried out. The results were as follows: the fashion information activities showed the highest discriminant rate. Next came the in-come level experience and age in that order Those four variables discrimated 37 from 50 who showed great achievement in design area (74%) and 51 from 83 in low achievement group (81%) Thus the total discriminant rate was 77.5%.