• Food Science and Preservation
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• v.20 no.3
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• pp.394-403
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• 2013

This study was performed to investigate the four-week repeated-dose toxicity of the crude antifungal compounds produced by Lactobacillus plantarum AF1 (Lb. plantarum AF1), a lactic acid bacterium isolated from kimchi, in male and female rats. Sprague-Dawley male and female rats were divided into four groups, with 10 animals in each group. The test article was administered once daily by gavage to rats at dosage levels of 0, 500, 1,000, and 2,000 mg/kg/day for four weeks. There were no test-article-related deaths or abnormal clinical signs in both the male and female rats during the observation period. Furthermore, no differences in the body weight changes, food intake and water consumption levels of the control and treatment groups were found. The hematological parameters, serum biochemical analysis results, histopathological examination results and all other findings also showed no significant or dose-dependent changes. There were also no changes in the organ weights upon the administration of the crude antifungal compounds produced by Lb. plantarum AF1. These results suggest that the oral administration of the crude antifungal compounds produced by Lb. plantarum AF1 had no adverse effects up to a dosage level of 2,000 mg/kg in both male and female rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.612-620
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• 2012

This study was performed to investigate the 4-week repeated-dose toxicity of $Lactobacillus$ $plantarum$ AF1 ($Lb.$ $plantarum$ AF1), a lactic acid bacteria isolated from kimchi, in male and female rats. Sprague-Dawley male and female rats were divided into four groups, with 10 animals in each group. The test article was administered once daily by gavage to rats at dosage levels of 0, 0.5, 1.0, and 2.0 g/kg/day for 4-weeks. There were no test articlerelated deaths or abnormal clinical signs in either gender of rat during the observation period. Furthermore, no differences were found between the control and treatment groups in terms of body weight changes, food intake, and water consumptions. Hematological parameters, serum biochemical analysis, and any other findings also showed no significant or dose-dependent alterations. There were no alterations in organ weights upon administration of $Lb.$ $plantarum$ AF1. These results suggest that there were no adverse effects of oral application of $Lb.$ $plantarum$ AF1 up to a dosage level of 2.0 g/kg in both male and female rats.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.189-196
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• 2003

In this study, the vertical opening of the non-float midwater pair trawl net was maintained by controlling the length of upper warp. This was because the head rope was able to be kept linearly and the working depth was not nearly as changed with the variation of flow speed as former experiments in this series of studies have demonstrated. We confirmed that the opening efficiency of the non-float midwater pair trawl net was able to be developed according to the increase in front weight and wing-end weight. In this study, we described the opening efficiency of the non-float midwater pair trawl net according to the variation of front weight and wing-end weight obtained by model experiment in circulation water channel. We compared the opening efficiency of the proto type with that of the non-float type. The results obtained can be summarized as follows：1. The hydrodynamic resistance was almost increased linearly in proportion to the flow speed and was increased in accordance with the increase in front weight and wing-end weight. The increasing rate of hydrodynamic resistance was displayed as an increasing tendency in accordance with the increase in flow speed. 2. The net height of the non-float type was almost decreased linearly in accordance with the increase in flow speed. As the reduced rate of the net height of the non-float type was smaller than that of the net height of the proto type against increase of flow speed, the net height of the non-float type was bigger than that of the proto type over 4.0 knot. The net width of the non-float type was about 10 m bigger than that of the proto type and the change rate of net width varied by no more than 2 m according to the variation of the front weight and wing-end weight. 3. The mouth area of the non-float type was maximized at 1.75 ton of the front weight and 1.11 ton of the wing-end weight, and was smaller than that of the proto type at 2.0∼3.0 knot, but was bigger than that of the proto type at 4.0∼5.0 knot. 4. The filtering volume was maximized at 3.0 knot in the proto type and at 4.0 knot in the non-float type. The optimal front weight was 1.40 ton.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.89-102
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• 2010

In this paper, a study on the future-oriented actuator introduces the future technology and future direction in aerospace and several industry fields. In particular, the mechanical linkage or hydraulic and pneumatic actuators which have the higher output-to-weight ratio have been used a lot in the past as the aircraft's flight control device. Most recently, Fly-By-Wire system has been used in aircraft and the flight control system has been changed in more electric and all electric systems. Electrohydraulic actuators and electric actuators have been developed continually, because they have better efficiency, safety and lower cost for the flight control system of aircraft. Also, to improve the weight condition, accuracy and response of actuator, new field actuators using new materials have been developed. In this paper we clearly proposed the actuator design and detailed technology development trend for next generation actuation system in aerospace and new field.

• Journal of Nutrition and Health
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• v.23 no.6
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• pp.401-407
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• 1990

This study was performed to investigate the effect of protein intake on kidney development and function in growing rats. Fourty-two male Spraque-Dawley rats of weighing $97.5\pm1.9g$ were divided into 3 groups and given 5%, 15% or 50% casein diets for 6 weeks. Body weight gain was higher in the 50% group. The kidney weight was selectively affected more by the level of dietary protein compared to the other organs. DNA and RNA content were significantly higher in the 15% and 50% groups than in the 5% group but the differences disappeared when DNA and RNA were expressed per g of kidney weight. Protein and protein/g kidney content were increased with increasing level of protein in diet. GFR/animal and GFR/100gB. W. were significantly higher in the 50% group compared to the 5% and 15% groups. There was no differences in PAH clearence and RBF. Osmolality was not affected by dietary protein level. BUN and urinary nitrogen excretion were increased with the increasing dietary protein level. Although urinary Ca excretion was not significantly difference among 3 groups, the rats in the 5% group showed 30% less Ca excretion compared to the other groups. Above results suggest that dietary protein level has a great effect on the kidney weight and GFR in growing rats. Especially the hyperfiltration inhanced by high protein diet may accelerate the kidney senescence.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.233-239
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• 2019

An unmanned underwater vehicle is a major weapon system that allows surveillance and reconnaissance missions in border areas or threatening areas where enemy submarines are present. Unmanned underwater vehicles can be used to explore underwater resources, predict disasters, and survey the topography of the ocean floor in the civilian fields, while in the defense fields, it can be used for anti-submarine reconnaissance and mine countermeasures. In this paper, we first investigate the main classification of unmanned underwater vehicles, and foreign R&D trends are analyzed based on the main classification criteria by weight, such as portable, light, heavy and large-scale unmanned underwater vehicles. Then we examine the trends in the development of domestic unmanned underwater vehicles. Finally, through the analysis of both domestic and foreign unmanned underwater vehicles, we present future development trends of unmanned underwater vehicles in order to set defense goals to counter the anticipated threats and diversified potential environment.

• Journal of Nutrition and Health
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• v.36 no.4
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• pp.352-358
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• 2003

This study was performed to investigate the effects of liquid culture of Agaricus blazei on the lipid metabolism and enzyme activities in growing male rats. Sprague-Dawley rats were given four different types of diets for a succeeding period of 5 weeks, respectively: a normal diet group (7% corn oil), a high fat diet group (7% com oil + 15% lard), a 20 or 30% Agaricus diet groups (high fat diet + 20 or 30% Agaricus in water) according to the levels of Agaricus supplementation. The body weight gains, food intake, food efficiency ratios, and hepatic, kidney, spleen and pancreas weights of the rats fed 20 or 30% Agaricus diets were similar to those of the rats fed high fat diet. The epididymal fat pad weight of the rats fed high fat diet and 20 or 30% Agaricus diets were significantly higher than that of the rats fed normal diet. The concentrations of serum triglyceride, total cholesterol, LDL-cholesterol and HDL-cholesterol, and the activity of glutamic pyruvic transaminase in the rats fed 30% Agaricus diet were significantly lower than those in the rats 114 high fat diet. But the concentrations of hepatic total cholesterol and triglyceride of rats fed the 20 or 30% Agaricus diets were similar to those of rats fed the high fat diet. The HDL-oholesterol/total-cholesterol ratio of the rat fed 30% Agaricus diet was significantly higher than that of the rats fed high fat diet, The activity of glutamic oxaloacetic transaminase in the rats fed 20 or 30% Agaricus diets were similar to those in the rats fed high fat diet. There were no differences in the concentrations of total protein, hemoglobin and glucose, and the activities of alkaline phosphatase, and the atherogenic index in the serum among the experimental groups. These results showed that the 30% Agaricus diet feeding decreased the total cholesterol, the triglyceride and the LDL-cholesterol, and increased the HDL-oholesterol/total cholesterol ratio in serum of rats.

• Journal of Nutrition and Health
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• v.37 no.2
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• pp.88-94
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• 2004

The effects of liquid culture of Coriolus versicolor on weight gain, food intakes, food efficiency ratios, serum and hepatic lipid concentrations, serum protein levels and serum enzyme activities, were studied in growing male rats. Sprague-Dawley rats were given four different types of diets for a succeeding period of 5 weeks, respectively: a normal diet group (7% corn oil), a high fat diet group (7% corn oil＋15% lard), a 20% or 30% C. versicolor diet groups (high fat diet＋20% or 30% C. versicolor in water) according to the levels of C. versicolor supplementation. The body weight gains of the rats fed the 30% C. versicolor diets were lower than those in the rats fed high fat diet. The epididymal fat pad weight of the rats fed high fat diet and 20% or 30% C. versicolor diets were significantly higher than that of the rats fed normal diet. The concentrations of triglyceride in the serum and the liver of the rats fed the 30% C. versicolor diets were more significantly decreased compared to rats on the high fat diet. The concentrations of total cholesterol in the serum and the liver of rats fed the high fat diet, 20% and 30% C. versicolor diets were similar to those of rats fed the normal diet. The HDL-cholesterol concentration and the HDL-cholesterol/total-cholesterol ratio of the rats fed 20% and 30% C. versicolor diets were significantly lower than those of the rats fed high fat diet. But the antherogenic index of the rats fed 20% or 30% C. versicolor diets were significantly higher than those of the rats fed high fat diet. There were no differences in the activities of glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and alkaline phosphatase in the serum among the experimental groups. These results showed that the 30% C. versicolor diet feeding decreased the triglyceride in serum and liver of the rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.957-962
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• 2012

The principal objective of this study was to determine the effects of an ethanol extract of Polygonum multiflorum Thunberg (PMT) on body lipid metabolism in rats fed a high-cholesterol diet for 5 weeks. The rats were divided into 6 groups: a control group (I), a cholesterol-control group (II), a control group treated with 0.5% PMT (III), a control group treated with 1% PMT (IV), a cholesterol-control treated with 0.5% PMT (V), and a cholesterol-control group treated with 1% PMT (VI). Body weight gains and food efficiency ratios were not significantly different among the groups. The levels of serum blood glucose and triglycerides of the treated animals significantly decreased compared to the control and the cholesterol-control groups (p<0.05). There was a clear tendency of decreased LDL-cholesterol level in PMT-treated animals compared to the cholesterol-control group. However, no significant differences were observed in the serum HDL- and LDL-cholesterol levels. In the ratio of HDL-cholesterol to total cholesterol and HDL-cholesterol to LDL-cholesterol concentration, both the 0.5% PMT and 1% PTM extract intake groups had a higher percentage than in the control and cholesterol-control groups (p<0.05). In addition, the atherosclerotic index in serum was significantly lower in the PMT intake group than those in the group control and the cholesterol-control. These results indicated that the PMT extract was effective on the improvement of lipid metabolism in SD rats.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.121-131
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• 2012

To investigate the effect of dietary supplementation of freeze-dried plum (Prunus mume Siebold and Zucc., PMS) or omija meal (Schizandra chinensis Baill.; SCB) on growth performance, organ weights, blood biochemical profiles and antioxidant defense system, a total of 96, 3-day-old male broiler chickens were assigned to three dietary groups: (1) control diet, (2) control diet supplemented with PMS at 0.2%, (3) control diet supplemented with SCB at 0.2%. In vitro antioxidant activity, plum and omija extracts showed a significantly higher radical scavenging activity (RSA). In particular, omija extract showed much higher RSA than plum extract. Dietary addition of plum or omija did not affect body weight, feed intake, feed conversion and the relative weight of digestive organ in birds. Plasma triglyceride significantly (P<0.05) increased in birds fed the diet supplemented with omija compared with those fed control diet without affecting the other blood biochemical components. Furthermore, reduced form of glutathione (GSH) in the liver or muscle significantly (P<0.05) increased in birds fed the diet fortified with plum and omija. However, the specific activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-S-transferase (GST) and MDA (malondealdehyde) in the intestine, liver and muscle were not altered by dietary antioxidant sources. In conclusion, dietary plum and omija resulted in a positive effect on some antioxidant indicators such as increased in vitro RAS in extracts and in vivo GSH level in the liver and muscle without affecting growth performance. Therefore, dietary addition of 0.2% of plum or omija could be applicable as potential antioxidant sources in broiler chick production.