• 대한조선학회논문집
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• 제47권3호
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• pp.350-358
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• 2010

The present paper deals with the comparative study of resistance performance with refrigerated ice and synthetic ice according to the variation of hull form characteristics. The resistance test has been conducted in pack ice condition in each concentration condition. Stem angle has been chosen as main parameters for the variation of hull form characteristics. The correlation of performance between with the refrigerated ice and with the synthetic ice has been shown according to the variation for stem angles. The present study show the possibility of ice test in general towing tank with synthetic ice for the time-consuming research such as hull form optimization although that is confined in pack ice condition. The more parametric study for the properties of synthetic ice is expected to be conducted to have more close correspondence for the test results of refrigerated ice in near future.

• 한국해양공학회지
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• 제23권1호
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• pp.129-134
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• 2009

This paper reports on experimental investigations of self propulsion performance with synthetic (model) ice and refrigerated ice, which were conducted in a typical towing tank and ice tank, respectively. The main purpose of this research was to find the correlation between the selfpropulsion performance with synthetic ice in a typical towing tank and that with refrigerated ice in an ice tank. The different stresses between the synthetic ice and refrigerated ice influenced the self propulsion performance due to different ice and propeller interactions. A further study on the ice property variation for a self propulsion performance comparison is to be conducted in the near future.

• 대한조선학회논문집
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• 제44권4호
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• pp.389-397
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• 2007

This research describes a framework to compare and analyze the icebreaker(Terry Fox) resistance in pack ice condition between with a refrigerated ice and a synthetic ice. Model tests with a refrigerated ice have been conducted at Institute for Ocean Technology (IOT/NRC) and the tests with a synthetic ice were conducted at Pusan National University towing tank. For the validation of further tests of measurement and accuracy, the open water tests were first carried out with same model ship to compare the test results of both Institutes. Two different size of the wax-type synthetic ice were used and tests were conducted in pack ice of three different concentration ice conditions. The test results show that the difference of resistance between with synthetic and with refrigerated ice becomes larger according to the increase of ship speed. Although the quantity of resistance difference is not so small in high speed range, the present study is predicted to be used as a useful correlation between synthetic and refrigerated ice.

• 한국해양공학회지
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• 제22권5호
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• pp.83-86
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• 2008

This paper deals with the experimental works for the correlations of ice resistance for icebreaker with synthetic(model) ice in general towing tank and with refrigerated ice in ice tank. In order to find out the correlation, the density variation is mainly focused in the present study. The model of Terry-Fox ice breaker has been used for the present correlation study because many data are available to be compared. According to the increase of density, the correlation becomes better quantitatively as well as qualitatively. Other parametric studies such as an ice size, a friction coefficient, a bending moment, etc., are also expected to be carried out to have better correlation in a near future. This research could be the basis for the possibility of resistance test using a synthetic ice in a general towing tank instead of an expensive ice tank.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권1호
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• pp.116-131
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• 2013

The resistance performance of an icebreaking cargo vessel in pack ice conditions was investigated numerically and experimentally using a recently developed finite element (FE) model and model tests. A comparison between numerical analysis and experimental results with synthetic ice in a standard towing tank was carried out. The comparison extended to results with refrigerated ice to examine the feasibility of using synthetic ice. Two experiments using two different ice materials gave a reasonable agreement. Ship-ice interaction loads are numerically calculated based on the fluid structure interaction (FSI) method using the commercial FE package LS-DYNA. Test results from model testing with synthetic ice at the Pusan National University towing tank, and with refrigerated ice at the National Research Council's (NRC) ice tank, are used to validate and benchmark the numerical simulations. The designed ice-going cargo vessel is used as a target ship for three concentrations (90%, 80%, and 60%) of pack ice conditions. Ice was modeled as a rigid body but the ice density was the same as that in the experiments. The numerical challenge is to evaluate hydrodynamic loads on the ship's hull; this is difficult because LS-DYNA is an explicit FE solver and the FSI value is calculated using a penalty method. Comparisons between numerical and experimental results are shown, and our main conclusions are given.

• Journal of Advanced Research in Ocean Engineering
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• 제2권2호
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• pp.67-80
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• 2016

The resistance performance of an icebreaking cargo vessel with varied stem angles is investigated numerically and experimentally. Ship-ice interaction loads are numerically calculated based on the fluid structure interaction (FSI) method using the commercial FE package LS-DYNA. Test results obtained from model testing with synthetic ice at the Pusan National University towing tank and with refrigerated ice at the National Research Council's (NRC) ice tank are used to validate and benchmark the numerical simulations. The designed icebreaking cargo vessel with three stem angles ($20^{\circ}$, $25^{\circ}$, and $30^{\circ}$) is used as the target ship for three concentrations (90%, 80%, and 60%) of pack ice conditions. The comparisons between numerical and experimental results are shown and our main conclusions are given.

• 한국해양공학회지
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• 제22권3호
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• pp.64-70
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• 2008

A full-scale field experiment is an important part in the design of ships and offshore structures. Full-scale tests in the ice-covered sea, however, are usually very expensive and difficult tasks. Model tests in a refrigerated ice tank may substitute this difficulty of full-scale field tests. One of the major tasks to perform proper model tests in an ice towing tank is to select a realistic material for model ice which shows correct similitude with natural sea ice. This study focuses on the testing material properties and the selection of model ice material which will be used in an ice model basin. The first Korean ice model basin will be constructed at the Maritime & Ocean Engineering Research Institute (MOERI) in 2009. With an application to the MOERI ice model basin, in this study the material properties of EG/AD/S model ice of IOT (Institute for Ocean Technology) Canada, were tested. Through comprehensive bending tests, the elastic modulus and the flexural strength of EG/AD/S model ice were evaluated and the results were compared with published test results from Canada. Instead of using an ice model basin, a cold room facility was used for making a model ice specimen. Since the cold room adopts a different freezing procedure to make model ice, the strength of the model ice specimen differs from the published test results. The reason for this difference is discussed and the future development for a making model ice is recommended.

• 한국수산과학회지
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• 제21권3호
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• pp.177-183
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• 1988

정어리를 시료어로 하여 빙장법 및 $-1^{\circ}C$ 냉각해수저장법으로 저장하면서 시료어의 염도, K값,VBN, TMA, POV, TBA, 염용성단백질양, $Ca^{2+}-AT-Pase$ 활성 및 어묵의 물성변화 등을 비교 검토하여 다음과 같은 결과를 얻었다. 1. K값, VBN 및 TMA값을 통한 선도저하의 측면에서 살펴보았을 때 빙장법보다 냉각해수저장법이 선도저하 억제효과가 있음을 나타내었다. 2. POV 및 TBA값에 의한 지질산화 측면에서도 냉각해수저장법이 빙장법보다 지질산화의 억제효과가 있음을 나타내었다. 3. 염용성단백질량 및 $Ca^{2+}ATP$ ase 활성을 측정한 단백질 안정성의 측면에서도 냉각해수저장법이 효과적이었다. 4. 균의 증식억제도 냉각해수저장법에서 효과가 있다. 5. 어묵의 물성변화 즉 절곡시험 젤리강도, 보수력에서도 냉각해수저장법이 빙장법보다 효과가 있었다. 이상과 같이 여러가지 지표를 사용하여 실험한 결과, 냉각해수저장법이 빙장법보다 선도유지방법으로 우수함이 입증되었으므로, 현재 주로 사용되고 있는 빙장법을 냉각해수저장법으로 대치한다면 선도저하 때문에 사료로 이용되는 대부분의 정어리를 통조림 원료로 이용 가능하리라고 생각되므로, 정어리자원의 효율적인 이용면에서 국가적 차원에서 시급히 실용화되어야 할 것으로 생각되며, 이에 대한 기초자료로 활용화되었으면 한다.

• 한국식품조리과학회지
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• 제31권4호
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• pp.423-430
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• 2015

This study was carried out to investigate the effects of dandelion leaf, root and whole part extracts on the physicochemical characteristics of pork patties stored at $4^{\circ}C$ for 10 days. Four types of pork patties were evaluated: ice-water-added (T0), dandelion leaf extract (T1), dandelion root extract (T2) and dandelion whole part extract (T3). The pH decreased significantly during storage, but increased after 10 days of storage. The pH was highest in T0 during storage. The L value of T0 increased whereas T1, T2 and T3 did not significantly changed during storage. The a value decreased with a longer storage period, and the a values for T1, T2 and T3 were higher than that of T0 during storage. The b value did not change significantly during storage. The TBARS increased with a longer storage period, and the values for T0, T1, T2 and T3 were 0.87, 0.29, 0.47 and 0.31 mg MA/kg, respectively, after 10 days of storage. The VBN content value of T0 increased, but those of T1, T2 and T3 did not significantly change during storage. The water holding capacity of T0 decreased, but those of T1, T2 and T3 did not significantly change during storage. Cooking loss increased during storage and that of T0 was higher than those of T1, T2 and T3. Hardness and chewiness decreased while springiness and cohesiveness increased during storage.

• 한국포장학회지
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• 제28권1호
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• pp.67-73
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• 2022

The food cold chain refers to a technology and distribution supply chain applied to maintain a constant temperature suitable for the product from production (harvest) to delivery to consumers. In particular, in Korea, the insulation material used in the food cold chain is mostly EPS (Expanded Polystyrene), which is used as a transport container for various food cold chains. However, according to the government's eco-friendly policy, companies charge environmental contributions to the use of EPS, but due to its low price and convenience of handling, it is still used as a container for delivering food. In this study, in order to measure the domestic delivery environment of general refrigerated foods, changes in impact, temperature, and humidity during transport of the EPS packaging system containing foods and ice pack refrigerants were measured. As a result, there were 2?3 sections in which a high impact force of 40 G or more was generated during transport. This can cause damage to the product and EPS container. The difference in temperature and humidity changes by parcel transport routes is more than 30%, so it is necessary to present accurate standards for the domestic cold chain distribution environment. As a result of microbial experiments. the transportation period had a dominant effect on the increase in total viable count and E. coli count.