• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.59-60
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• 2018

The oscillating-water-column wave energy converter represents the complex physical characteristics associated with the water column, turbines, generator, and power converter. This study focuses on the derivation of the physical relationship between the water column and turbine based on the 1/ 4 scale model test. The aerodynamic characteristics of the OWC ducted turbine were simulated using an orifice. The turbine effect, a key element in the OWC-chamber performance evaluation, can be represented by the flow rate and pressure drop through the orifice. The turbine effect of OWC-WEC was confirmed to have a non-linear relationship from the measured flow rate and pressure drop in the model test.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1450-1459
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• 2001

These experiments were conducted to investigate the effects of different feeding and processing methods of diets on performance, morphological changes in the small intestine and nutrient digestibility of growing-finishing pigs. One-hundred fifty growing pigs ($Yorkshire{\times}Landrace{\times}Duroc$; initial body weight of $23.33{\pm}0.75kg$) and one-hundred twenty finishing pigs ($Yorkshire{\times}Landrace{\times}Duroc$; initial body weight of $59.22{\pm}0.56kg$) were used in Exp. 1 and Exp. 2, respectively. Pigs were grouped on the basis of body weight and gender, and randomly allotted into 6 different treatments with 5 replications in each treatment in a $2{\times}3$ factorial arrangement. Treatments were 1) dry feeding with a mash diet (DM), 2) dry feeding with a pelleted diet (DP), 3) dry feeding with an expanded crumble diet (DEC), 4) dry/wet feeding with a mash diet (WM), 5) dry/wet feeding with a pelleted diet (WP), and 6) dry/wet feeding with an expanded crumble diet (WEC). In Exp. 1 (growing phase), there was no significant difference in average daily gain (ADG) and average daily feed intake (ADFI) among treatments during the entire experimental period, but feed conversion ratio (FCR) was significantly (p<0.05) improved in pigs fed pelleted diets regardless of feeding method. FCR was best in pigs fed a DP diet and worst in pigs fed a WM diet. Pigs fed a pelleted diet showed a 6.2% or 4.0% improvement in FCR compared with those fed a mash diet or an expanded crumble diet. Water disappearance was not significantly affected by dry/wet feeding or feed processing. Significant differences in villus height were not found among treatments, but villus height tended to be improved by dry/wet feeding. Dry/wet feeding or feed processing did not affect crypt depth. Digestibilities of calcium and phosphorus were significantly (p<0.05) improved in pigs fed an expanded crumble diet compared with pigs fed mash diets. Especially, pigs fed a WEC diet digested 8.1% more P than those fed a DM diet. Feed cost per kg weight gain (FCG) tended to be increased by dry/wet feeding rather than dry feeding. In Exp. 2 (finishing phase), ADG and ADFI were not significantly different among treatments, but a significant difference in FCR was found among feed processing forms. The best FCR was obtained in pigs fed a pelleted diet. Pigs fed a DP diet showed a 11.3% improvement compared with those fed a DEC diet. Water disappearance was significantly (p=0.0408) decreased by feeding the mash diet. However, water disappearance was not affected by dry/wet feeding during the finishing period. The villus height and crypt depth were not significantly different among treatments. However, crypt depth tended to be decreased by dry/wet feeding at the mid part of the small intestine. Fat digestibility was improved by dry feeding rather than dry/wet feeding, and was improved by 4.8% by feeding pellet diets compared with expanded crumble diets. Except for carcass grade, carcass characteristics were not significantly (p<0.05) different among treatments. Carcass grade was the best in pigs fed a WP diet. Feed cost per kg weight gain (FCG) was significantly decreased in pigs fed a pelleted diet compared with those fed an expanded crumble diet, and tended to be decreased by dry/wet feeding. In conclusion, these studies suggest that feeding the pelleted diet to growing-finishing pigs can be beneficial in terms of FCR and production cost. Dry/wet feeding can be helpful for the maintenance of villus height, but may not be reflected in improved growth performance or reduction of production costs.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1308-1315
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• 2001

This study was conducted to evaluate the effects of different methods of feeding and processing of diets on performance, morphological changes in the small intestine and nutrient digestibility of young pigs. A total of 120 pigs (Youkshire${\times}$Landrace${\times}$Duroc; initial body weight of $5.83{\pm}0.67kg$) were randomly allotted into six treatments in a $2{\times}3$ factorial design. Treatments were 1) dry feeding with a mash diet (DM), 2) dry feeding with a pelleted diet (DP), 3) dry feeding with an expanded crumble diet (DEC), 4) wet feeding with a mash diet (WM), 5) wet feeding with a pelleted diet (WP), 6) wet feeding with an expanded crumble diet (WEC). Average daily gain (ADG) and average daily feed intake (ADFI) were not significantly (p>0.05) different among treatments. However, feed conversion ratio (FCR) was significantly improved when pigs fed a pelleted diet or an expanded crumble diet. Pigs fed an expanded crumble diet showed 9.2% and 17.3% improvement in ADG and FCR compared with those fed a mash diet. The morphological changes in the small intestine were examined at the termination (4 weeks after weaning) of the experiment. Differences in morphological changes of gastrointestinal tract were not significant among treatments. Though villus height was not significantly affected by feeding method or feed processing, the villus height of weaned pigs tended to be preserved by wet feeding. The use of a pelleted diet also helped to prevent the shortening of villus height. Pigs fed a WP diet maintained the highest villus height at all parts of the small intestine. There was no significant difference (p>0.05) in nutrient digestibility among treatments. However, nutrient digestibility for pigs fed a pelleted diet had a higher than that of pigs fed mash diets. Especially, pigs fed a WP diet digested 5.3% more P each day than those fed a DM diet. Compared with the mash diet, the expanded crumble diet decreased feed cost per kg weight gain by 15%. The net profit per pig was 79% higher in the expanded crumble diet pigs than in mash diet pigs. In conclusion, this study suggests that feeding processed diets to piglets can be more beneficial in terms of FCR and production cost.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.3
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• pp.147-153
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• 2013

There exist various types of the WEC (Wave Energy Converter), and among them, the point absorber is the most popularly investigated type. However, it is difficult to find examples of systematically measured data analysis for the design of the point absorber type of power buoy in the world. The study investigates the wave load acting on the point absorber type resonance power buoy wave energy extraction system proposed by Kweon et al. (2010). This study analyzes the time series spectra with respect to the three-year wave data (2002.05.01~2005.03.29) measured using the pressure type wave gage at the seaside of north breakwater of Hupo harbor located in the east coast of the Korean peninsula. From the analysis results, it could be deduced that monthly wave period and wave height variations were apparent and that monthly wave powers were unevenly distributed annually. The average wave steepness of the usual wave was 0.01, lower than that of the wind wave range of 0.02-0.04. The mode of the average wave period has the value of 5.31 sec, while mode of the wave height of the applicable period has the value of 0.29 m. The occurrence probability of the peak period is a bi-modal type, with a mode value between 4.47 sec and 6.78 sec. The design wave period can be selected from the above four values of 0.01, 5.31, 4.47, 6.78. About 95% of measured wave heights are below 1 m. Through this study, it was found that a resonance power buoy system is necessary in coastal areas with low wave energy and that the optimal design for overcoming the uneven monthly distribution of wave power is a major task in the development of a WEF (Wave Energy Farm). Finding it impossible to express the average spectrum of the usual wave in terms of the standard spectrum equation, this study proposes a new spectrum equation with three parameters, with which basic data for the prediction of the power production using wave power buoy and the fatigue analysis of the system can be given.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1606-1610
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• 2004

This study was. conducted to investigate the effects of $\delta$-aminolevulinic acid supplementation on growth. performance, nutrient digestibility and hematological changes in weaned pigs. Seventy five Duroc${\times}$Yorkshire${\times}$ Landrace pigs (7.21$\pm$0.02 kg average BW) were used in a 20 d growth assay. Dietary treatments included 1) NC (negative control; basal diet), 2) PC (positive control; NC diet + 0.1% Apramycin + 0.1% Oxytetracycline), 3) ALA0.l (NC diet+0.l% $\delta$-aminolevulinic acid), 4) ALA0.2 (NC diet+0.2% $\delta$-aminolevulinic acid) and 5) ALA + AB (PC diet+0.2% $\delta$-aminolevulinic acid). In entire experimental period, ADG (Average Daily Gain) was greater in pigs fed ALA + AB diet than in pigs fed NC diet (p<0.05). However, there was no significant difference in ADG for pigs fed PC, ALA0.l or ALA0.2 diets. Also, ADFI (Average Daily Feed Intake) and G/F (Gain/Feed) were not affected by treatments. For 20 d, fecal digestibilities of DM (Dry Matter) and N (Nitrogen) were higher (p<0.05) for pigs fed ALA + AB diet than for pigs fed NC and ALA0.l diets. Total protein concentration of serum was increased in ALA + AB treatment compared to NC and PC treatments (p<0.05). In iron concentration of serum, pigs fed $\delta$-aminolevulinic acid supplementation diets were greater than for pigs fed NC and PC diets (p<0.05). TIBC (Total Iron Binding Capacity) concentration of serum was increased in ALA + AB treatment compared to NC, PC and ALA0.l treatments (p<0.05). Pigs fed ALA + AB and ALA0.2 diets were higher hemoglobin (Hb) and hematocrit (HCT) concentration of blood than pigs fed NC and PC diets (p<0.05). RBC and WEC concentrations of blood were significantly higher (p<0.05) for the pigs fed ALA0.2 and ALA + AB diets than for pigs fed NC diet. Lymphocyte concentration of blood was increased in $\delta$-aminolevulinic acid supplementation treatment compared to NC treatment (p<0.05). In conclusion, $\delta$-aminolevulinic acid supplementation for weanling pigs had improved growth performance and nutrient digestibilities and had increased total protein, iron, hemoglobin and lymphocyte concentration of blood. Also, feeding for dietary $\delta$-aminolevulinic acid and antibiotic mixture supplementation may have more higher effective growth performance in weanling pigs.

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.239-245
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• 2001

Background: Acute idiopathic thrombocytopenic purpura(ITF) is one of the common hematologic disorders in children. Bone marrow aspiration (BMA) is often performed in children with acute ITP to rule out leukemia, aplastic anemia or other hematologic diseases. However, whether BMA is needed in children with typical clinical and hematological features of acute ITP have been questioned. This study was performed to examine the proper indication of BMA in acute childhood ITF. Materials and Methods: The medical records and BMA reports of children with the provisional diagnosis of acute ITP were reviewed from January 1984 to December 2000. Patients were divided into two groups, one with typical and another with atypical clinical and hematological features of acute ITP. Typical acute ITP group was characterized by the history of previous viral infection, well being appearance, no hepatosplenomegaly, no lymphadenopathy, normal Hb, WEC, neutrophil count and peripheral blood smear except thrombocytopenia. A platelet count of $50{\times}l0^9/L$ or lower was the cutoff level. Results: Total 120 children with the provisional diagnosis of acute ITP were included. One hundred eighteen of them were confirmed to have acute ITP by BMAs. Of these, 66 had typical and 54 had atypical features. All of typical features and 52 of 54 with atypical features of acute ITP were confirmed to have acute ITP by BMAs. Two patients with atypical features of acute ITP were diagnosed as aplastic anemia and myelodyspalstic syndrome, respectively, by BMAs. Conclusion: This study concludes that BMA is not needed for the children with typical features of acute ITP but it is needed for the children with atypical features of acute ITP to rule out other hematologic disorders.