• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.725-730
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• 2011

A 2-way solenoid valve regulates to maintain the pressure of ullage volume of propellant tanks when the command is given by control system for the liquid-propellant feeding system of space launch vehicle. The simulation model of solenoid valve for pressurization is designed with AMESim to verify the designs and evaluate the dynamic characteristics and pneumatic behaviors of valve. To validate a valve simulation model, the simulation results of their operating durations of valve by AMESim analysis are compared with the results of experiments. Using the model, we analyze performance of valve; opening/closing pressure, operating time on various design factors; shape of control valve seat, basic valve seat, rate of sealing diameter. This study will serve as one of reference guides to enhance the developmental efficiency of ventilation-relief valves with the various operating conditions, which shall be used in Korea Space Launch Vehicle-II.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.109-116
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• 2012

A vent-relief valve performs as a safety-valve assembly for liquid propellant feeding system of space launch vehicle, which relives pressurant propellant tanks during the filling and the flight. At vent mode, valve is opened and closed by driving pneumatic pressure, and at relief mode, valve is automatically operated to set relief pressure. In this study, we have analyzed a basic layout of vent-relief valve which is designed using foreign LVs(Saturn) to satisfy requirements of Korean Space Launch Vehicle. The simulation model of vent-relief valve is designed by using the AMESim code to verify design parameters and evaluate pneumatic behaviors of valve. In this study, we performed dynamic characteristic simulations on design parameters. And we could predict opening/closing time and pressures, operating performances on design parameters. Using this results, we could suggest detail design and boundary conditions of design.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.6
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• pp.70-77
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• 2011

A ventilation-relief valve performs as a safety-valve assembly for the liquid-propellant feeding system of space launch vehicle. This valve plays a role of relieving the vaporized propellants from propellant tanks during the filling and storing stages of propellants. Also it regulates to maintain the pressure of ullage volume of on-board propellant tanks within the safety-margin during the flight. The simulation model of ventilation-relief valve is designed with AMESim to predict and evaluate the dynamic characteristics and pneumatic behaviors of valve. To validate a valve simulation model, the simulation results of the opening and closing pressures and their operating durations of valve by AMESim analysis are compared with the results of mathematical methods. In addition, the results of internal flow simulation with FLUENT are utilized to improve the accuracy of valve-modeling. This study will serve as one of reference guides to enhance the developmental efficiency of ventilation-relief valves with the various operating conditionss, which shall be used in Korea Space Launch Vehicle-II.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.453-459
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• 2014

Chronic mild stress (CMS) has been reported to induce an anhedonic-like state in mice that resembles some of the symptoms of human depression. In the present study, we used a chronic mild stress animal model of depression and anxiety to examine the responses of two strains of mice that have different behavioral responsiveness. An outbred ICR and an inbred C57BL/6 strain of mice were selected because they are widely used strains in behavioral tests. The results showed that the inbred C57BL/6 and outbred ICR mice were similarly responsive to CMS treatment in sucrose intake test (SIT) and open field test (OFT). However, the two strains showed quite different responses in forced swimming test (FST) and novelty-suppressed feeding (NSF) test after 3 weeks of CMS treatment. Only C57BL/6 mice displayed the depression- and anxiety-like behavioral effects in response to CMS treatment in FST and NSF test. Our results suggest that there are differences in responsiveness to CMS according to the different types of strain of mice and behavioral tests. Therefore, these results provide useful information for the selection of appropriate behavioral methods to test depression- and anxiety-like behaviors using CMS in ICR and C57BL/6 mice.

• Korean Journal of Community Nutrition
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• v.10 no.2
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• pp.151-162
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• 2005

This study was conducted to investigate the nutritional status and factors related to dislike of vegetables in the students who avoid eating vegetables in elementary school. The subjects were classified into VDG (vegetable dislike group, 75 children) and control group (69 children) by amount of vegetable left in school feeding. The survey included the items of demographic characteristics, dietary behaviors, nutrition knowledge, food preference, reason for dislike of vegetables and nutrient intake of the subjects. Dietary behavior and nutrition knowledge scores of control group were higher than those of VDG. The average score of food preference was 4.9 and 4.7 in control and VDG groups respectively. The preference score of root vegetables was the lowest in subjects. In the view of nutrient intake, the calorie intake of control group was higher than that of VDG. Protein intake of control and VDG was enough as compared with their RDA. Except vitamin E, most nutrient intake of control group was higher than that of VDG. VDG consumed lower calorie, vitamin A, vitamin $B_2$, vitamin C, Ca, P, Fe and Zn than control group. The scores of the dietary behavior and nutrition knowledge in the subjects were positively related to the status of some vitamins and minerals intake. These results show that the scores of nutrition knowledge and dietary behavior of VDG were lower than those of control, causing low intake of vitamins and minerals such as vitamin A, Ca and Fe.

• Journal of Korean Academy of Nursing Administration
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• v.7 no.2
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• pp.315-347
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• 2001

The purpose of this study was to validate the linkage of nursing diagnosis(NANDA) and Nursing Interventions Classification(NIC) for implementing the Nursing Diagnosis and Nursing interventions in Korea. 36 nurse experts with over the bacculate degree and over 15 years experiences working in tertiary hospitals participated in this study. 5 point Likert scales on each NIC linked 136 NANDA diagnoses were adopted. The results were as follows: 1. In a validity of linkage of nursing diagnosis and nursing interventions classification, the highest score is in 'Chronic low self esteem'(4.66), the lowest score is in 'sensory/Perceptual alterations; Auditory'(3.34) and the average validity score of the total items is 4.27. 2. There was significant differences by educational level and experience in validity score. 3. The nurses who have master degree have higher score than bachelor degree in the diagnoses; 'fatigue', 'health seeking behaviors', 'nutrition: potential for more than body requirements, altered', 'powerlessness'. 4. The nurses with experience over 20 years have higher validity score than less 15 years in 'breast-feeding, effective'. In conclusion, this research indicates that the linkage of NANDA diagnoses and NIC with high validity score can be applied to nursing practice in Korea. And further studies of nursing intervention are needed in Korean culture.

• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.301-309
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• 1996

LBD-001, a recombinant human interferon ${\gamma}$ produced by genetically engineered yeast as a host system, was intravenously administered to pregnant female rats (Sprague-Dawley) from day 7 to 17 of gestation at dose levels of 0.35$\times$10$^{6}$ , 0.69$\times$10$^{6}$ , and 1.38$\times$10$^{6}$ I.U./kg/day. As the control groups, hydrocortisone sodium succinate (5 or 10 mg/kg/day) was also similarly administered. Teratological effects of the test agents on fetuses and development of offsprings (F1 rats) were investigated. (1) No significant changes by the treatment of LBD-001 were observed in body weight, food and water consumption, feeding and nursing behaviors, and autopsy of pregnant or lactating mother rats. However, in hydrocortisone sodium succinate (10 mg/kg/day)-treated group, significant decreases of body weight on day 16, 18, and 20 of gestation and food consumption on day 20 of gestation and outstanding atrophy of thymus and adrenals were observed in two rats autopsied on day 20 of gestation. (2) No significant changes in resorption rate, skeletal or visceral development of fetuses, and physical or sensory development of offsprings (Fl) by the treatment of LBD-001 were detected. In hydrocortisone sodium succinate (10 mg/kg/day)-treated group, however, there were significant decreases of body weight of fetuses, delay of ossification, temporary delay of body weights of offsprings (F1) on day 1 and 3 of lactation, and increased tendency of stillborn rate and malformation rate of bone. The results show that LBD-001 at the dose of 1.38$\times$10$^{6}$ I.U./kg/day or less is not teratogenic in organogenesis of fetuses and the development of offsprings (F1). Meanwhile, hydrocortisone sodium succinate (10 mg/kg/day) seems to delay ossification of fetuses and temporarily retard the development of offsprings (Fl).

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.2
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• pp.128-134
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• 2013

A 2-way solenoid valve regulates to maintain the pressure of ullage volume of propellant tanks when the command is given by control system for the liquid-propellant feeding system of space launch vehicle. The simulation model of solenoid valve for pressurization is designed with AMESim to verify the designs and evaluate the dynamic characteristics and pneumatic behaviors of valve. To improve the accuracy of the model, numerical flow analysis by using FLUNET code. The simulation results of their operating durations of valve by AMESim analysis are matched up with the results of experiments and validate valve model. Using the model, we analyze performance of valve; opening/closing pressure, operating time on various design factors of basic valve and control valve; geometrical size of valve seat, ratio of basic valve and sealing area.

• Animal Bioscience
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• v.35 no.12
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• pp.1817-1826
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• 2022

Public concern on the methods of raising food-producing animals has increased, especially in the last two decades, leading to voluntary and mandated changes in the animal production methods. The primary objective of these changes is to improve the welfare of farm animals. The use of gestational stalls is currently a major welfare issue in swine production. Several studies assessed the welfare of alternative housing systems for gestating sows. A comparative study was performed with gestating sows housed in either individual stalls or in groups in a pen with an electronic sow feeder. This review assessed the welfare of each housing system using physiological, behavioral, and reproductive performance criteria. The current review identified clear advantages and disadvantages of each housing system. Individual stall housing allowed each sow to be given an individually tailored diet without competition, but the sows had behavioral restrictions and showed stereotypical behaviors (e.g., bar biting, nosing, palate grinding, etc.). Group-housed sows had increased opportunities to display such behavior (e.g., ability to move around and social interactions); however, a higher prevalence of aggressive behavior, especially first mixing in static group type, caused a negative impact on longevity (more body lesions, scratch and bite injuries, and lameness, especially in subordinate sows). Conclusively, a more segmented and diversified welfare assessment could be beneficial for a precise evaluation of each housing system for sows. Further efforts should be made to reduce aggression-driven injuries and design housing systems (feeding regimen, floor, bedding, etc.) to improve the welfare of group-housed sows.

• Animal Bioscience
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• v.36 no.4
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• pp.601-608
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• 2023

Objective: This study was conducted to investigate the effects of energy and protein levels in the diet of Hanwoo heifers on growth response and animal behavior. Methods: Forty heifers were randomly allocated into three experimental groups according to the target daily weight gain in 8 pens (T-0.2, 2 replications; T-0.4 and -0.6, 3 replications) based on similar body weight (BW) and age in months. The target average daily gain (ADG) was set at 0.2 (T-0.2), 0.4 (T-0.4), and 0.6 kg/d (T-0.6), and feed was based on National Institute of Animal Science (NIAS, 2017). In order to minimize hunger stress of T-0.2 and -0.4, the feeding ratio of rice straw was set to 55%, 50%, and 45% for T-0.2, -0.4 and T-0.6, respectively, so that the dry matter (DM) intake for all treatment groups was uniform but the energy and protein levels in the diet were adjusted differently. A total of 6 items (lying, standing, eating, rumination, walking and drinking) of animal behavior were analyzed. Results: During the whole period of the experiment, the ADG of the T-0.2, -0.4 and -0.6 treatments were 0.48, 0.56, and 0.65 kg/d (p<0.05), respectively, showing higher gain than the predicted value, especially for the low target ADG group. Based on these results, regression equations for the total digestible nutrient (TDN) and crude protein (CP) requirements were derived. No behavioral differences were found according to the energy and protein levels in the diet because the DM intake was kept constant by adjusting the roughage and concentration ratio. However, eating time was longer (p<0.05) at T-0.2 than T-0.6 during the whole day. Conclusion: Through this study, it was possible to derive regression equations for predicting TDN and CP requirements according to the target ADG and BW.