• The Journal of Fisheries Business Administration
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• v.37 no.2 s.71
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• pp.19-32
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• 2006

The sea environment must be preserved for maintaining various coastal resources. In order to preserve the sea environment, this study is to find problems in the process of producing photocatalyst materials, which can purify sea pollution, and to develop the heuristic algorithm satisfying those problems. The heuristic algorithm of this paper is developed through constructing the mathematical model and analyzing the mathematical structure of variables and constraints in that model. The algorithm developed in this paper consists of the first process of initializing, the second process of lot combination and the third process of improving solutions. Some experimental results are given to verify the effectiveness of the heuristic algorithm developed in this paper.

• Journal of information and communication convergence engineering
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• v.14 no.2
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• pp.129-135
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• 2016

In this paper, we present a novel algorithm for image-based maritime obstacle detection using global sparsity potentials (GSPs), in which "global" refers to the entire sea area. The horizon line is detected first to segment the sea area as the region of interest (ROI). Considering the geometric relationship between the camera and the sea surface, variable-size image windows are adopted to sample patches in the ROI. Then, each patch is represented by its texture feature, and its average distance to all the other patches is taken as the value of its GSP. Thereafter, patches with a smaller GSP are clustered as the sea surface, and patches with a higher GSP are taken as the obstacle candidates. Finally, the candidates far from the mean feature of the sea surface are selected and aggregated as the obstacles. Experimental results verify that the proposed approach is highly accurate as compared to other methods, such as the traditional feature space reclustering method and a state-of-the-art saliency detection method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.699-705
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• 2013

This paper presents vibration testing, control, and finite element analysis of a piping system, which is subjected to the changes in fluid levels. Nuclear power plants typically employ a cooling system that uses sea water. These systems are subjected to dynamic characteristic changes caused by sea-level variations, which introduces failures of cooling system components. Therefore in this study, analytical and experimental studies were performed to understand the effect of sea-level changes on the dynamic characteristics of piping systems. It was shown that, as the sea-level increases, pipe's natural frequencies decreases in relation to its mode shape. A 1/14 scale model was also built to compare the results obtained by the analytical study. A good agreement between experiment and analytical studies were observed. Finally, an on-line resonant frequency identification system was proposed and developed, which utilizes piezoelectric transducers as sensors and actuators, in order to avoid catastrophic failure of piping systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4117-4123
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• 2013

In the present study, coating corrosion characteristics of the heat exchanger for sea water are experimentally investigated. Coating types by a teflon, an electrodeposition and a ceramic+silicon were tested and compared with the corrosion characteristics of an aluminum. For the acceleration of corrosion by sea water, the temperature of sea water $70^{\circ}C$ and the concentration of salt 3.5% were considered. And the specimens were immersed in sea water during 9 weeks. Coating corrosion characteristics were measured by using the impedance method and SEM. Experimental results showed that polarization resistances obtained from Bode plot were related to the corrosion resistance of coating types, and the corrosion resistance of double coating were maintained during 4 weeks. From SEM photograph, we saw that blisters was generated on the interface between metal and coating.

• Journal of Nutrition and Health
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• v.32 no.3
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• pp.230-238
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• 1999

The present study was conducted to investigate te effect of sea tangle and hypoglycemic agent(Metformin) on lipid peroxidation and antioxidants levels in normal and diabetic rats. Male Sprague-Dawley rats were fed AIN-76 based experimental diets containing 5% (w/w) cellulose or 15%(w/w) sea tangle for 3 weeks, and then rats of diabetic groups were rendered diabetic by intramuscular injection of streptozotocin(STZ, 45mg/kg BW). After induction of diabetes Metformin(350mg/kg BW) was given once a day using a feeding tube for 5 days. Blood glucose level in diabetic rats fed sea tangle was significantly lower than that of diabetic rats fed cellulose. Metformin feeding resulted in further lowering blood glucose. Plasma and liver microsomal levels of lipid peroxides were increased significantly in diabetic rats as compared to normal rats, and the plasma level tended to be decreased by sea tangle feeding. Plasma level of retinol was reduced by STZ treatment, but it was increased by Metformin feeding in diabetic rats fed sea tangle. The liver contents of retinyl plamitate were reduced in diabetic rats but recovered by sea tangle feeding to some extent. Liver contents of total vitamin A were increased significantly by sea tangle in diabetic rats. Although difference in either plasma or liver level of $\alpha$-tocopherol by diet and STZ treatment was not significant, $\alpha$-tocopherol levels were the highest in the group with simultaneous feeding of sea tangle and metformin. Liver contents of zinc and copper were not influenced by either STZ treatment or sea tangle feeding. The present study indicates that the lowering blood glucose level could be attained by simultaneous trial of sea tangle diet and hypoglycemic agent and the increased oxidative stress caused by STZz treatment could be relieved by sea tangle feeding.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.891-898
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• 2017

Climate changes consistently cause coastal accidents such as coastal flooding, so the studies on monitoring the marine environments are progressing to prevent and reduce the damage from coastal accidents. In this paper, we propose a new method to estimate the sea level which can be applied to the tidal sensors to monitor the variation of sea level. Existing sea level models are very complicated and need a lot of tidal data, so they are not proper for tidal sensors. On the other hand, the proposed algorithm is very simple but precise since we use the measured data from the sensor to estimate the sea level value in short period such as one or two hours. It is shown by experimental results that the proposed method is simple but predicts the sea level accurately.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.8
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• pp.606-612
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• 2014

Vehicle simulation models for noise and vibration prediction have been developed so far generally in two schemes. One is FE models generally used for problems below 200 Hz such as booming noise, and the other is SEA models for high frequencies of more than 1 kHz, representatively related to sound packages. There have been many researches to develop a simulation model for 200~1000 Hz, so-called mid-frequency region, and this paper shows one practical result that covers the trimmed body of a sedan vehicle. The simulation model is developed based on an FE model, and then FE elements at some areas are substituted with SEA elements to reduce DOFs. SEA panels are described by modal density, radiation efficiency, stiffness and damping characteristics that are found from some numerical assessments. Sound packages are modeled similarly as a conventional SEA model. The results obtained from the hybrid model were compared to experimental results. Predicted pressure and vibrational velocity generally show a good agreement. The developed simulation model and related technology are successfully being used in vehicle development process.

• Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.279-283
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• 2013

We tested the effects of various distillers dried grains (DDGs) in a formulated diet on growth and body composition of juvenile sea cucumber Apostichopus japonicus. DDG is a solid residue obtained by filtering an aqueous mixture of fermented rice with Aspergillus oryzae and yeasts. Six isonitrogenous and isocaloric diets (DDG0, DDG-G, DDG-C, DDG-K, DDG-W, and DDG-P) were formulated to contain 20% DDG obtained from different Makgeolli factories. Juvenile sea cucumber (average weight, $2.1{\pm}0.02$ g) were randomly distributed in eighteen 50-L rectangular plastic tanks (40 L of water each) in a seawater flow-through system at a density of 50 juveniles/tank. Three replicate groups of sea cucumber were fed each of the six experimental diets at a feeding rate of 5% body weight per day for 22 weeks. At the end of the feeding experiment, survival and weight gain of the juvenile sea cucumber were not affected by the type of dietary DDG (P > 0.05), and the proximate and amino acid compositions of the whole body were not affected by dietary DDG diets (P > 0.05). These results indicate that rice-based DDG is a potential dietary ingredient that could be used at dietary concentrations of up to 20% for growth of juvenile sea cucumber.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.2
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• pp.202-213
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• 2014

The sea cucumber, Apostichopus japonicus, is becoming an important aquaculture species in China, Japan and Korea. The purpose of this study is to evaluate the biological performance of a tubular type of subsurface cage for sea cucumber grow-out by in-situ tests. The cage structure was constructed of PP (polypropylene) frames and PP tubes (${\phi}130mm{\times}24pieces$). A set of tests were conducted at a depth of 15 m near Seosaeng, Ulsan, Korea for 295 days (23 July, 2012 to 13 May, 2013). A total of 155 sea cucumbers were used and fed a mixed diet containing mud, mineral, wheat, fish meal, etc (3% of their body weight). At the end of the experiments, sea cucumber showed a higher survival rate in feed shelter (77.14%) rather than no feed shelter (64.71%). The specific growth rate (SGR) of sea cucumbers in feed condition (0.04% $day^{-1}$) was higher than that of no feed culture animals (-0.49% $day^{-1}$) during total experimental periods. The result was able to find a no significance difference in survival rate but a significance difference in SGR under feed and no feed treatments.

• Journal of the Korean Society of Food Culture
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• v.22 no.1
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• pp.140-148
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• 2007

Diabetic nephropathy has been increasing, although blood glucose and blood pressure can be controlled by angiotensin converting enzyme(ACE) or advanced glycosylation end products(AGE) inhibitors in the diabetic patients. We investigated the effect of dietary supplementation of sea tangle on the blood glucose, and pathological scoring of diabetic kidneys in the streptozotocin(STZ) induced diabetic rats. Male Sprague-Dawley rats were divided into normal rats fed control diet and diabetic rats fed control diet or control diet supplemented with powder or oater extract of sea tangle. Diabetes was induced by a single injection of STZ(60mg/kg, ip) in citrate buffer. The animals were fed the experimental diet and water for 13 weeks. Dietary supplementation of sea tangle decreased blood glucose in the diabetic rats. However, dietary supplementation of sea tangle did not affect the antioxidant enzyme activities, MDA content and pathology of diabetic kidneys. These results indicate that decreased blood glucose by sea tangle could not delay the progression of diabetic kidney disease.