• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.235-239
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• 2016

The capsizing speed of an unstable vessel with a lost restoring moment can be understood as a unique response to an accident situation, and is naturally affected by such parameters as moment of inertia, metacentric height, and transverse damping coefficient of the hull in the case of free roll motion. Additionally, it is supposed that the analysis of capsize accidents can be further simplified when a vessel's leaning velocity is shown to be quite low. Therefore, capsize accidents with low leaning speeds are desirably categorized in view of rescuing strategies, as opposed to fast capsize accidents, since the attitude of the declining hull can be properly estimated, which allows rescuers to have more time for helping accident cases. This study focuses on deriving some analytical equations based on the roll decay ratio parameter, which describes how a hull under a low-speed capsize is related to the situational hull characteristics. The suggested equations are applied to a particular ship to disclose the analytical responses from the model ship. It was confirmed that the results show the general characteristics of slow capsizing ships.

• Composites Research
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• v.21 no.1
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• pp.22-29
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• 2008

This paper presents the evaluation of crashworthiness and rollover characteristics of low-floor bus vehicles made of aluminum honeycomb sandwich composites with glass-fabric epoxy laminate facesheets. Crashworthiness and rollover analysis of low-floor bus was carried out using explicit finite element analysis code LS-DYNA3D with the lapse of time. Material testing was conducted to determine the input parameters for the composite laminate facesheet model, and the effective equivalent damage model for the orthotropic honeycomb core material. The crash conditions of low-floor bus were frontal accident with speed of 60km/h. Rollover analysis were conducted according to the safety rules of European standard (ECE-R66). The results showed that the survival space for driver and passengers was secured against frontal crashworthiness and rollover of low-floor bus. Also, The modified Chang-Chang failure criterion is recommended to predict the failure mode of composite structures for crashworthiness and rollover analysis.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.399-408
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• 2014

Glutathione S-transferases (GSTs) are a superfamily of detoxification enzymes that primarily catalyze the nucleophilic addition of reduced glutathione to both endogenous and exogenous electrophiles. In this study, we isolated and characterized a full-length of alpha class GST cDNA from the abalone (Haliotis discus hannai). The abalone GST cDNA encodes a 223-amino acid polypeptide with a calculated molecular mass of 25.8 kDa and isoelectric point of 5.69. Multiple alignments and phylogenetic analysis with the deduced abalone GST protein revealed that it belongs to the alpha class GSTs and showed strong homology with disk abalone (Haliotis discus discus) putative alpha class GST. Abalone GST mRNA was ubiquitously detected in all tested tissues. GST mRNA expression was comparatively high in the mantle, gill, liver, and digestive duct, however, lowest in the hemocytes. Expression level of abalone GST mRNA in the mantle, gill, liver, and digestive duct was 182.7-fold, 114.8-fold, 4675.8-fold, 406.1-fold higher than in the hemocytes, respectively. Expression level of abalone GST mRNA in the liver was peaked at 6 h post-infection with Vibrio parahemolyticus and decreased at 12 h post-infection. While the expression level of abalone GST mRNA in the hemocytes was drastically increased at 3 h post-infection with Vibrio parahemolyticus. These results suggest that abalone GST is conserved through evolution and may play roles similar to its mammalian counterparts.

• Journal of Auto-vehicle Safety Association
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• v.5 no.1
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• pp.50-55
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• 2013

When it comes to commercial vehicles, their unique characteristics - center of gravity, size, weight distribution - make them particularly vulnerable to rollover. On top of that, conventional heavy vehicle brake exhibits longer actuation delays caused in part by long air lines from brake pedal to tires. This paper describes rollover prevention algorithm that copes with the characteristics of commercial vehicles. In regard of compensating for high actuating delay, predicted rollover index with short preview time has been designed. Moreover, predicted rollover index with longer preview time has been calculated by using road curvature information based on environment information. When rollover index becomes larger than specific threshold value, desired braking force is calculated in order to decrease the index. At the same time, braking force is distributed to each tire to make yaw rate track desired value.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.613-620
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• 2012

This study was carried out to investigate changes in nutrient composition and fermentation properties in abalone mul-kimchi using dried pollack stock (AMKP) and licorice stock (AMKL) during storage at $4^{\circ}C$ for 35 days. The levels of moisture (88.37-90.94%) and crude ash (2%) did not differ much between AMKP and AMKL during the 35 days of storage. But crude protein and crude lipid levels decreased gradually until 21 days of storage. AMKP and AMKL fermentation during 21 days led to a decrease in pH, increased acidity, and the highest Leuconostoc sp. count. AMKP and AMKL showed acidity of 0.50% at pH 4.30, when the kimchi samples were ripened properly. Glutamic acid showed the highest content in AMKP and AMKL, and hydroxypoline was the most abundant of all free amino acids. We have provided basic data for commodification research on abalone mul-kimchi.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.385-391
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• 2018

Abalone aquacultural industry has been growing rapidly in a short period of time, however, there has been just a few researches related to the forecast of the supply, demand and price. Even the models developed by these researches have problems of low compatibility and reliability. To resolve these problem, a biological supply model needs to be developed that maintains time difference and linkage among the quantity of juvenile abalone into the plots, quantity of cultivation, quantity of shipment, and at the same time juvenile abalone is transplanted into the plot, matured and shipped by the expected market price. This study focus on the development of the model for determining quantity of the abalone cultivation, which is the core part of the entire abalone demand and supply model. Key factors that affect cultivation quantity were identified and verified the causal relationship among these variables and cultivation quantity. It turned out that the quantity of juvenile abalone transplanted and the relative price(the abalone price of the place of produce divided by the brown seaweed price) have a great influence on the cultivation quantity. Also, the similarity of the variation for the cultivation quantity of the observed value and the forecasted value implies that the model developed in this study has a high compatibility.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.2
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• pp.227-235
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• 2018

Along with the recent increase in traffic volume of vehicles, accidents involving rollover of vehicles have been rapidly increased, resulting in an increase casualties. And to prevent this, various technologies such as vehicle crash test equipment and analysis program development have been advanced. In this study, the applied vehicle model is FORD EXPLORER model, and PC-Crash program for vehicle collision analysis is used to predict the rollover accident behavior of SUV and the collision velocity. Compared with the actual rollover behavior of SUV through the FMVSS No 208 regulations, the analysis results showed similar results, the characteristics of the collision velocity and roll angle showed a tendency that the error rate slightly increased after 1000 msec. Then, as a result of considering using the database of NHTSA, it is shown that the rollover accident occur most frequently in the range of the collision velocity of 15~77 km/h and the collision angle of $22{\sim}74^{\circ}$. And it is possible to estimate the vehicle speed and collision time when the vehicle roof is broken by reconstructing the vehicle starting position, the roof failure position and the stop position by applying the actual accident case.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.376-385
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• 2023

Fishing boat capsizing accidents account for more than half of all capsize accidents. These can occur for a variety of reasons, including inexperienced operation, bad weather, and poor maintenance. Due to the size and influence of the industry, technological complexity, and regional diversity, fishing ships are relatively under-researched compared to commercial ships. This study aimed to predict the rolling motion time series of fishing boats using an image-based deep learning model. Image-based deep learning can achieve high performance by learning various patterns in a time series. Three image-based deep learning models were used for this purpose: Xception, ResNet50, and CRNN. Xception and ResNet50 are composed of 177 and 184 layers, respectively, while CRNN is composed of 22 relatively thin layers. The experimental results showed that the Xception deep learning model recorded the lowest Symmetric mean absolute percentage error(sMAPE) of 0.04291 and Root Mean Squared Error(RMSE) of 0.0198. ResNet50 and CRNN recorded an RMSE of 0.0217 and 0.022, respectively. This confirms that the models with relatively deeper layers had higher accuracy.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.316-317
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• 2018

선박의 대형화, 고속화 및 선종의 다양화는 운송수단 중 해양 운송수단의 비중을 크게 증가시켰으나, 동시에 선박사고의 발생도 같이 증가되었다. 여객선의 경우 인명의 피해가 크게 발생하기 때문에 선박사고를 예방하기 위한 방법들이 논의되어 지고 있다. 본 연구에서는 여객선의 횡경사 각도를 바탕으로 전복의 위험까지 가게 되는 시간을 예측하여 위험시간에 도달하기 전에 인명을 대피할 수 있는 기초 자료를 제공하고자 하였다. 특정 시나리오를 설정하여, MOSES를 이용한 시뮬레이션을 수행하였으며 선형방정식을 이용하여 시뮬레이션 결과와 비교하였다.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.71-82
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• 1999

Irregular motions of nonlinear dynamic system are the result of an intrinsic characteristics that the system have, and sometimes occur unpredictable large motion. For a ship in a regular seaway, the capsizing occur because of this unexpectable motion. So, from the safety's point of view, nonlinear ship motions should be treated carefully. In this study, stable and unstable regions are investigated firstly under the variation of a control external force. Secondly, we consider the attractors to know how ship motions of the stable region that does not undergo capsizing change. Thirdly, bifurcation diagram is considered to study the range in detail where nonlinear chaotic motions are occurred.