• International Journal of Naval Architecture and Ocean Engineering
• /
• v.8 no.5
• /
• pp.466-474
• /
• 2016

The model tests results for the original lines of an 10000TEU container vessel show that the delivered power is higher and could not satisfy the requirement of energy saving effects and design targets. In this paper, the lines optimization of the 10,000 twin-skeg container vessel was carried out by parametric modeling and CFD simulations. At first, the CFD methods for twin-skeg hull form were validated by the comparison with the experimental results. Then more than one hundred parameters were adopted for the establishment of the fully parametric model. Based on the parametric model of the twin-skeg container vessel, the preliminary optimization was carried out by tight coupling of FRIENDSHIP-FRAMEWORK with potential flow of SHIPFLOW. Then several important parameters related to the after part of twin-skeg vessel were investigated by viscous flow computation. The final optimized variant PM11, which the total resistance was reduced by about 8.3% in model scale, is obtained within the constraints of general arrangement. And the model tests for variant PM11 was carried out in CSSRC, which shows that the resistance of optimized variant PM11 is decreased by about 8.6%.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.16 no.6
• /
• pp.21-28
• /
• 2012

Welded Unreinforced Flange-Welded Web (WUF-W) connection is one of Special Moment Frame (SMF) specified in ANSI/AISC-358. From the experimental test of WUF-W connection specimens conducted by the previous study, fracture occurred in the beam flange before achieving total inter-story drift angle of 0.04radian required for Special Moment Frames (SMF) system even though the specimens satisfied the design and detailing requirement specified in ANSI/AISC-358. These results are estimated as problem of the access hole geometry. In this study, a full-scale WUF-W connection specimen was made with a modified access hole geometry, and tested with the same test setting and loading as the previous test. From test results, the deformation capacity of the tested WUF-W connection specimen exceeded 4%, which is required for connections in SMF system. Comparing with the WUF-W specimens of the previous study, the strain demand of the beam flange in the tested specimen was decreased and energy dissipation capacity of the specimen was improved.

• Structural Engineering and Mechanics
• /
• v.24 no.3
• /
• pp.339-354
• /
• 2006

Hangzhou Bay Bridge spans the Hangzhou Bay and is located at Zhejiang province in the southeast seacoast of China. The total length of the bridge is 36 km. The bridge is composed of bridge approaches made up of multi-span prestressed concrete box girders and two cable-stayed bridges over the north and south navigable spans respectively. The seismic response analysis of the bridge model shows that if the navigable spans are designed as the routine earthquake-resistance system, the displacements and internal forces in pylons, piers and deckes are too large to satisfy the anti-seismic requirement of the structure. Therefore, the seismic reduction design was carried out by using viscous dampers to dissipate the kinetic energy of the structure both longitudinally and transversely. Using the vibration reduction system and aiming at the reasonable optimal goal, the purpose to reduce the seismic responses in south and north navigable spans has been achieved.

• Advances in concrete construction
• /
• v.10 no.6
• /
• pp.489-498
• /
• 2020

This paper investigates mechanical properties of roller compacted concrete (RCC) involving reclaimed asphalt pavement (RAP). In this way, a set of 276 cylindrical RCC specimens were prepared with different RAP sizes (i.e., fine, coarse & total) at various ratios (i.e., 10%, 20%, and 40%). Results reveal that incorporation of RAP decreases unconfined compressive strength (UCS), modulus of elasticity (E), and indirect tensile (IDT) strength of RCC. For each RAP size, a regression model was used to maximize RAP content while satisfying the UCS lower limit (27.6 Mpa) mentioned by ACI as a minimum requirement for RCC used in pavement construction. Moreover, UCS of RAP incorporated mixes, dissimilar to that of control mixes, was found to be sensitive and insensitive to the testing temperature and curing time after 7 days, respectively. The results also demonstrate that the higher amounts of RAP, the more flexibility in RCC is. This issue was also proved by the results of modulus of elasticity test. In addition, the toughness index (TI) shows that increase in RAP content leads to up to 43% increase in energy absorbance capacity of RCC.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.10
• /
• pp.1624-1632
• /
• 2020

Objective: A total of three hundred unsexed ducks were utilized to estimate net energy requirements of maintenance (NE_m) and weight gain (NE_g) for 2 to 3-week-old Cherry Valley ducks and to establish a model equation to predict NE requirements using the factorial method. Methods: To determine the apparent metabolizable energy (AME) of the diet, fifty 7-day-old ducks at approximately equal body weights (BWs) were randomly assigned into five groups that were fed at different levels (ad libitum, 85%, 75%, 65%, and 55% of ad libitum intake), and the endogenous acid-insoluble ash as indigestible marker. The two hundred and fifty 7-day-old ducks were used for a comparative slaughter experiment. At the beginning of the experiment, ten ducks were sacrificed to determine the initial body composition and energy content. The remaining ducks were randomly assigned into five groups (same as metabolic experiment). Ducks of the ad libitum group were slaughtered at 14 and 21-day-old. At the end of the experiment, two ducks were selected from each replicate and slaughtered to determine the body composition and energy content. Results: The results of the metabolizable experiment showed AME values of 13.43 to 13.77 MJ/kg for ducks at different feed intakes. The results of the comparative slaughter experiment showed the NE_m value for 2 to 3-week-old Cherry Valley ducks was 549.54 kJ/kg of BW^0.75/d, and the NE_g value was 10.41 kJ/g. The deposition efficiency values of fat (K_f) and crude protein (K_p) were 0.96 and 0.60, respectively, and the values of efficiency of energy utilization (K_g) and maintenance efficiency (K_m) were 0.75 and 0.88, respectively. Conclusion: The equation for the prediction of NE requirements for 2 to 3-week-old Cherry Valley ducks was the following: NE = 549.54 BW^0.75+10.41 ΔW, where ΔW is the weight gain (g).

• Journal of the Korean Dietetic Association
• /
• v.7 no.3
• /
• pp.217-226
• /
• 2001

It is important to supply adequate nutrition to critically ill patients, whose gastrointestinal system is properly functioning, through the enteral tube feeding if oral intake is impossible. In this study we investigated the changes in nutritional status with enteral tube feeding according to the volume required. We investigated the volume ordered according to the patient's requirements, volume infused according to the volume ordered in 41 enteral tube feeding patients in intensive care unit from Jannuary to July, 2000. Body weight, serum albumin level, and total lymphocyte count were evaluated to assess nutritional status. The mean fasting period was 5 days before the enteral feeding and patients whose fasting period over 3 days were 51%. The mean enteral tube feeding period was 29 days and method of feeding was nasogastric, bolus feeding 6 times per day. The volume ordered was 69.7% of the patients' recommended calorie and volume infused was 86.6% of their volume prescribed. Accordingly, the volume infused was estimated 61.7% of their volume required. Only 44.6% of their reqiured volume was infused within 3 days after enteral tube feeding was started. It took 16 days in average to meet the patients' recommended calorie; 56% of subjects still did not fully met their requirements by the end point. Among the impeding factors in supplying enteral tube feeding, factors related to the number of feeding were high residual volume in stomach, vomiting, gastrointestinal bleeding, abdominal distension and surgery. Factors related to the acctual infused volume were diarrhea, gastrointestinal bleeding, abdominal distension, airway management and tube reinsertion. Significant correlations were shown between the volume infused and changes in both the patients' weight and serum albumin level. Deviding the subjects into two groups by their infused volume, less than 70% and more than that, we compared the two to come up with a significant difference in their serum albumin level, -0.23 vs 0.21, and their body weight, -4.52 vs 0.12. In enteral tube feeding, the volume delivered in sufficient to the pateints' energy requirement can affect their nutriitional status in critically ill patient; adequate nutritional management plan is essential. It is necessary to make every effort to educate clinical staff and to set up a unified management program to prescribe adequate ammount of energy for the patient's nutritional requirement.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.40 no.2
• /
• pp.111-116
• /
• 2020

This study was conducted to determine the maintenance energy requirements of growing goats in order to establish an appropriate energy benefit system, to reduce feed costs and improve livestock productivity of goat farmers, and to present basic data for detailed specifications afterwards. This experiment was conducted as a group specification test for a total of 3 months, with 32 goats of three months age and conducted by four treatments with different energy levels (T1: NRC+0%, T2: NRC+10%, T3: NRC+20%, and T4: NRC+30%). The average daily gain was the highest in the treated with NRC + 10% of the energy level of the experimental diet, and the feed conversion ratio was in the range of 6.3 g to 7.3 g in the group feeding experiment. Although there was no significant difference in digestibility between treatments, the digestibility of dry matter, crude protein, and crude fat was higher in T2 treated with NRC + 10% than the other treatments. Through the regression equation of the values of MEI and ADG obtained through the experiment (Y=0.5439X+111.51, R²=0.712), the maintenance energy requirement of the goat in the growing period was estimated to be 111.51 kcal/kgBW^0.75.

• Korean Journal of Community Nutrition
• /
• v.15 no.3
• /
• pp.393-402
• /
• 2010

The purpose of this study was performed to evaluate the prevalence of overweight and to compare the dietary behaviors, nutrient intake and physical activities of specialized game high school students. Total of 163 subjects participated and their weight, height, waist circumference, hip circumference and bone status by a quantitative ultrasound method were measured. The subjects were surveyed by a self-administered questionnaire about general characteristics, dietary behaviors and physical activities. Nutrient intakes of the subjects were assessed by semi-quantitative food frequency questionnaire. The subjects were divided into four groups on their obesity level by BMI. The prevalence of underweight, normal, overweight and obese group was 6%, 58%, 16%, and 20% respectively. BMI was negatively correlated with bone mineral density (p < 0.01) and positively correlated with WHR (p < 0.01). The dietary guideline compliance score for "Enjoy Korean rice food style" was 2.63, followed by "Prepare food sanitarily"2.48, "Do not skip breakfast"2.29, "Eat a variety of vegetables, fruits, dairy products daily"2.25, "Drink water instead of beverage"2.10, "Choose less fried foods"2.09 and "Maintain healthy weight"1.91. The exercise frequency of walking was not significantly different between groups; however, heavy exercise frequency was significantly lower in underweight group than the other groups (p < 0.05). The energy intake was 2153 kcal, which was 81.2% of the Estimate Energy Requirement, and the intake of calcium and vitamin $B_2$ was 66.7% and 77.8% of KDRIs. Particularly, the intake of iron, vitamin A and vitamin C was about 59.4%, 52.2% and 55.4% of KDRIs and INQ was 0.71, 0.63 and 0.65 respectively, and intake of folic acid fell behind 39.1% of KDRIs and INQ was 0.46. Our study suggests that the systematic and continuous nutrition education will have to be provided at schools to improve dietary and health behaviors and prevent chronic metabolic disease for students of specialized game high school.

• Korean Journal of Community Nutrition
• /
• v.13 no.1
• /
• pp.100-110
• /
• 2008

Recently, a lot of epidemiological studies revealed that low HDL-cholesterol level was a better predictor of risk for coronary heart disease than total cholesterol. This study investigated the anthropometric parameters, clinical blood indices, and dietary factors influencing serum HDL-cholesterol level by using a cross-sectional study for Korean female college students. The subjects were 94 female college students. They were divided into three groups according to their serum HDL-cholesterol levels, low HDL-cholesterol (<50 mg/dL, n=20), medium HDL-cholesterol (50 $\leq$, < 60 mg/dL, n=39) high serum HDL-cholesterol groups (60 $\leq$ mg/dL, n = 35). This study examined their demographic data and dietary intake throughout a questionnaire. Clinical blood indices were measured using an automatic blood chemistry analyzer (Selectra E), after 12 hours of fasting. BMI, body weight, fat mass, and waist circumferences were significantly increased according to low serum HDL-cholesterol levels. Serum lipid analysis showed a significantly higher level of TG, LDL-/HDL-Ratio, atherogenic index in the low HDL-cholesterol group. Serum levels of GPT, uric acid and alkaline phosphatase in the low HDL-cholesterol group were significantly higher than in the other group. The average consumption of energy was 1627 kcal and 77.76% of estimated energy requirement (EER). The mean ratio of calories from carbohydrate: protein: fat was 57:15:28. The low HDL-cholesterol group was significantly higher than the other groups in eggs, fat and oils consumption. Interestingly, milk and diary products consumption of low HDL-cholesterol group was half (p < 0.05) of those of the other groups. In conclusion, serum HDL-cholesterol levels appeared to be decreased by increasing BMI, fat mass, waist circumference, and serum TG level. In addition, some dietary factors seemed to be related to serum HDL-cholesterol levels. However, further research is needed to elucidate the exact relationship between serum HDL-cholesterol level and dietary factors.

• Journal of Ocean Engineering and Technology
• /
• v.31 no.2
• /
• pp.81-90
• /
• 2017

The 1MW OTEC (Ocean Thermal Energy Conversion) platform was designed for application in equatorial seas. In this study, the OTEC platform was investigated using numerical and experimental methods. An octagon-shaped OTEC platform was investigated using the Ocean Engineering Basin of KRISO. These experiments included various tests of regular waves, irregular waves and irregular waves with current (wave+current). The responses of the platform in regular waves showed good agreement between the numerical and experimental results, including the motion RAO, wave run up, and mean drift force. The peak period of heave and pitch motions were observed around 0.5 rad/s, and the effect of the total reflection was found under short wave conditions. The standard deviation (STD) of the platform motion was checked in irregular waves of equatorial and Hawaiian seas. The STD of the pitch was less than $4^{\circ}$ different from the operability requirement under equatorial conditions and the surge STD of the wave frequency showed good agreement between the numerical and experimental results. The STD values of the surge and pitch were increased 66.6% and 92.8% by the current effects in irregular waves, but the pitch STD was less than $4^{\circ}$ under equatorial conditions. This study showed that the STD of the surge was affected by spring effects. Thus, the watch circle of the platform and tension of the mooring lines must be evaluated for a specific design in the future.