• Journal of Electrical Engineering and Technology
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• 제12권5호
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• pp.1934-1944
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• 2017

As a key component of high-voltage power conversion system for electric vehicles (EVs), bidirectional DC/DC (Bi-DC/DC) is required to have high efficiency and light weight. Conventional design methods optimize the Bi-DC/DC at the maximum power dissipation point (MPDP). For EVs application, the work condition of the Bi-DC/DC is not strict as the MPDP, where the design method using MPDP may not be optimal during travel of EVs. This paper optimizes the Bi-DC/DC converter targeting efficiency and weight based on the driving cycle. By analyzing the two-phase interleaved Bi-DC/DC for hybrid energy storage systems (HESS) of EVs, its power dissipation is calculated, and an efficiency model is derived. On this basis, weight models of capacitor, inductor and heat sink are built, as well as a dynamic temperature model of heat sink. Based on these models, a method using New European Driving Cycle (NEDC) for optimal design of Bi-DC/DC which simultaneously considered efficiency and weight is proposed. The simulation result shows that compare with conventional optimization methods revealed that the optimization approach based on driving cycle allowed significant weight reduction while meeting the efficiency requirements.

• Journal of Electrochemical Science and Technology
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• 제12권1호
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• pp.58-66
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• 2021

Spiral-wound woven wire meshes packed bed rotating cylinder electrode was used for the simultaneous removal of cadmium (Cd) and copper (Cu) from a binary solution. The effects of weight percent of each metal on the removal and current efficiencies were studied at an operating current of 345A, while the effect of current on the removal efficiency of both metals was investigated at three levels of current (240, 345.and 400 mA). The experiments were carried out at constant rotation speed 800 rpm, pH = 3, and a total concentration of metals (500 ppm). The results showed that the removal efficiency of copper increased from 89% to 99.4% as its weight percent increased from 20% to100%. In a similar fashion, the removal efficiency of cadmium increased from 81% to 97% as its weight percent increased from 20% to100%. The results confirmed that the removal efficiency of any metals declined in the presence of the other. Increasing of current resulted in increasing the removal efficiency of both metals at different weight percents. The results confirmed that current efficiencies for removing of copper and cadmium simultaneously decline with increasing of electrolysis time and weight percent of cadmium or with decreasing the weight percent of copper. Current efficiency was higher at the initial stage of electrolysis for all weight percents of metals. The results showed that the decay of copper concentration was exponential at all weight percents of copper, confirming that the electrodeposition of copper is under mass transfer control in the presence of cadmium. While the decay of cadmium concentration was linear at lower weight percent of cadmium then changed to an exponential behavior at high weight percent of cadmium in the presence of copper.

• 생명과학회지
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• 제5권3호
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• pp.126-136
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• 1995

The studies had been conducted to evaluate the grain processing effects for ruminants on starch digestion, body weight gain and feed efficiency since 1970. This research deals with experimental results on chemical structure, gelatinization, microbial starch digestion in rumen, intestinal starch digestion in rumen, roles of protozoa, intestinal starch digestion of bypass starch, limits to starch digestion in small intestine. The grain processing has different effects on digestion, weight gain and feed efficiency when different grain sources and contents is used, and the quality and quantity of roughage is different. The economical and efficient method of grain processing should be selected considering weight gain and feed efficiency enhancement than digestibility.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.532-537
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• 2005

Increasing of body weight has been one of the important economic factors in the poultry industry. Insulin-like growth factor (IGF)-I is a polypeptide that serves to regulate muscle development and body growth. Moreover, IGF-I is related to feed efficiency. However, there are few studies regarding the regulatory roles of chicken IGF-I/-II compared with that of mammals. Especially, the Korean Native Ogol Chicken (KNOC) has a lean body growth and its body weight is generally lighter than the broiler chicken. Therefore, this study was conducted to investigate associations among serum IGF-I/-II concentration, feed efficiency, and body growth in KNOC. The body weight and feed intake of KNOC were recorded from 20 to 36 weeks at 2 weeks intervals, and blood was taken every 2 weeks. Serum IGF-I/-II were measured by RIA. Chickens were divided into two groups, high and low serum IGF-I concentration. Generally, feed efficiency and growth performance (body weight and weight gain) in the high serum IGF-I group were higher than those of the low group during the experimental period. In particular, the body weight of the IGF-I high group were significantly different from those of the IGF-I low group at 34 and 36 weeks, respectively (p<0.05). Moreover, body weight, weight gain, and feed efficiency had a significant correlation with serum IGF-I at several weeks (p<0.05 and p<0.01). These results show that IGF-I plays an important role in body growth and suggests a possibility that serum IGF-I could be used as a selection marker for body growth in KNOC.

• 수산해양기술연구
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• 제50권3호
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• pp.262-273
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• 2014

To investigate the catching efficiency of a biodegradable round trap for a swimming crab (Portunus trituberculatus), four types of material (two types of biodegradable net, one type of biodegradable plus polyethylene net and one type of polyethylene net) for traps were used in the field test, and the field tests were carried out 11 times in the Boryeong fishing ground of Korea, 2012~2013. The catching efficiency of four type traps was analyzed by catch per trap, weight per trap and mean weight per individual of small and large size swimming crab. Statistical Kruskal-Wallis test was carried out to verify the significant difference for the efficiency between types of material. The catch in number of swimming crab was 9,015 and formed about 94.3% of total catch. In the results of catching efficiency of traps, there was a little difference in catch per trap, weight per trap and mean weight per individual of swimming crab in-situ data. But there was no significant difference in catching efficiency between the biodegradable traps and the PE trap (P>0.05), so it's needed to use widely a biodegradable trap for the conservation and sustainable management of swimming crab resources.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권1호
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• pp.111-115
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• 2004

Nutrition plays an important role in maintaining the larval health, cocoon quality and reproductive potential in Antheraea mylitta D. Nutritional efficiency greatly influenced if food is not adequate and of quality. A. mylitta silkworms were subjected to food deprivation for the period of 0 hr to 12 hrs /day to assess its effect on various nutritional parameters and indices, and its manifestation at different levels. Food ingesta, digesta, gain in body weight declined significantly at each level of deprivation, so also food utilization efficiency like consumption index (CI), growth rate (GR), approximate digestibility (AD), and efficiency of conversion of ingested food (ECI). This stress leads to decline in mean daily food ingesta by 16.73% to 39.76% and digesta by 28.98% to 54.01 % following a significant reduction in average daily body weight gain (27.68% to 55.09%). Food deprivation a1so caused significant loss in the silk gland weight, cocoon and shell weight (14.37% to 53.69%), lowered the fecundity (35.86 % to 83.59%) and in number of eggs laid per gram body weight, but simultaneously the number of non-chorionated eggs increased significantly.

• 전기학회논문지
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• 제65권4호
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• pp.561-566
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• 2016

In this paper, effective design method of linear induction motor(LIM) for Maglev is proposed in order to maximize system efficiency of Maglev. For the high system efficiency of Maglev, it is important to minimize weight of traction motor. Light weight design by changing materials of core and winding is conducted without changing volume of LIM. For the silicon steel core of primary part for magnetic flux path, iron-cobalt alloy steel with high magnetic saturation characteristic compared to silicon steel is suggested. Moreover, aluminium winding with light weight instead of copper winding is wounded in the widen slot area due to the high magnetic saturation level. For the verification of performance of proposed model, the characteristics are analyzed by using finite element method(FEM).

• Asian-Australasian Journal of Animal Sciences
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• 제10권2호
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• pp.240-244
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• 1997

This study was conducted in North Sulawesi, Indonesia to identify the factors affecting reproductive efficiency and to determine the contribution of each factor in reproductive efficiency of Indonesian native cows. Records of reproductive efficiency, body size (hip height, body weight, body length, heart girth) as well as age on one hundred and sixty seven Indonesian native cows (seventy six cows of the Bali breed and ninety one cows of the synthetic breed from unknown proportion of th Madura, the Sumba and the Ongole breeds) of 58 farmers were available in this research. The data were analyzed by covariance analysis using SAS package including reproductive efficiency as a dependent variable and breed, body size (hip height, body weight, body length, heart girth) and age of cows as independent variables. The contribution of each independent factor to dependent variable was estimated as the percentage of the sum of square in the corrected total sum of squares. The results showed that body weight and body size of cows would be considered as th most important factors affecting reproductive efficiency of Indonesian native cows. Therefore, the reproductive efficiency could be increased by 1) using cows that reached a target weight of at least 250 kg, 2) using cows with relatively well developed height at hip of at least 117 cm, heart girth of at least 150 cm, and body length of at least 125 cm, 3) keeping breeding cows that reach a target age of 24 months old with the maximum interval between postpartum and next breeding season of 90 days for each year, and 4) using good nutritional feeding to reach the optimum weight and body condition.

• 생명과학회지
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• 제6권4호
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• pp.278-285
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• 1996

This experiments was conducted to determine the effect of dietary fiber(DF) levels with diets of isocaloric (3,010 kcal/1kg diet) and isoprotein(21% of diet) on colored brolier chicks(Juk jun hatchery farm). Four groups of 6 chicks 4 replication. were fed corn-soy meal diets containing 0% (DF, 5%), 2%(DF, 6%), 4%(DF, 7%), and 6%(DF, 8%) of dehydrated alfalfa meal(AM) from 21 to 42 days of age. The addition of dietary fiber levels to the broiler chicks diets did noty affect body weight, feed efficiency, energy efficiency and protein efficiency, but affect feed intake of chicks fed 6% of fiber. The level of fiber diets did not affect gizzard weight of female(1.45g/100g BW) and male(1.25g/100g BW), but affect small intestine length of female. When comparing two the dietary fiber levels, 5% and 8%, the contents of the total serum cholesterol was slightly higher in chicks fed 5% of fier than that of 8% without significant. However, total serum cholesterol levels of female(121mg/dl) and male(119mg/dl) were not influenced by increased dietary fiber levels. The liver weight was not influenced by increasing of dietary fiber levels (female 2.03g and male 2.05g/100g BW). The yields of dressed weight(72% of shrunk body weight), skin weight)11% of dressed weight) were not influenced by increased dietary fiber.

• The Journal of Korean Physical Therapy
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• 제14권2호
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• pp.199-218
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• 2002

This study was conducted to examine obese children's self-efficiency feeling and health promotion behavior in order to provide basic information on prevention of children obesity. Data were collected in June, 2001 from 349 normal weight children and 351 obese children, who were fifth or sixth graders at 14 primary schools located in Seoul, Busan, Daegu, Gwangju, Ansan, chungju, and Gumi. The data were analyzed through using Chronbach's $\alpha$, frequency analysis, $X^2-test$, ANOVA, and Pearson correlation. The results of this study can be summarized as follow. 1. The factor of children obesity was significantly different in the variables of sex, parents obesity, brother or sister obesity, father's occupation, level of living, health condition, and satisfaction level with their bodies. On the other hand, it was not significantly different in the variables of father's education level, mother's education level, mother's occupation, level of father's concern about health, and level of the children's concern about health. 2. In the case of normal weight children, dietary efficiency feeling was significantly different in the variables of level of father's concern about health and level of children's concern about health. In th case of obese children, the dietary efficiency feeling was significantly different in the variables of mother obesity, parents' education level, father's occupation, and the children's satisfaction level with their bodies. In the case of normal weight children, exercise efficiency feeling was significantly different in the variables of sex, level of parents's concern about health, and level of the children's concern about health. In the case of obese children, the exercise efficiency feeling was significantly different in the variables of grade, brother and sister obesity, parents' education level, father's occupation, and the children's satisfaction level with their bodies. In the case of normal weight children, social efficiency feeling was significantly different in the variables of brother and sister obesity, parents' education level, level of parents' concern about health, and level of the children's concern about health. In the case of obese children, the social efficiency feeling was significantly different in the variables of parents' education level, father's occupation, level of living, the children's health condition, and the children's satisfaction level with their bodies. 3. In the case of normal weight children, personal hygiene was significantly different in the variables of sex, level of parents's concern about health, and level of the children's concern about health. In the case of obese children, the personal hygiene was significantly different in the variables of parents' education level, father's occupation, mother's occupation, level of living, and level of parents' concern about health. In the case of normal weight children, dietary habit was significantly different in the variables of sex, level of parents's concern about health, and level of the children's concern about health. In the case of obese children, the dietary habit was significantly different in the variables of father's education level, mother's education level, level of living, and the children's satisfaction level with their bodies. In the case of normal weight children, exercise habit was significantly different in the variables of grade, sex, father's education level, mother's education level, and level of children's concern about health. In the case of obese children, the exercise habit was significantly different in the variables of grade, mother obesity, parents' education level, father's occupation, level of parent' concern about health, the children's health condition, and the children's satisfaction level with their bodies. In the case of normal weight children, prevention of infectious diseases was significantly different in the variables of sex, father's occupation, level of parents' concern about health, and level of the children's concern about health. In the case of obese children, the prevention of infectious diseases was significantly different in the variables of mother's education level and father's occupation. In the case of normal weight children, prevention of accident was significantly different in the variables of mother's education level, level of parents' concern about health, and level of the children's concern about health. In the case of obese children, the prevention of accident was significantly different in the variables of brother and sister obesity and mother's occupation. In the case of normal weight children, mental health was significantly different in the variables of father obesity, brother and sister obesity, parents' education level, and level of the children's concern about health. In the case of obese children, the mental health was significantly different in the variables of parents' educational level, father's occupation, mother's occupation, level of living, and the children's health condition. 4. According to the correlation between self-efficiency feeling and health promotion behavior, the higher the self-efficiency feeling was, the higher the level of health promotion behavior was. 5. The children obesity was influenced by the factors of level of living, level of parents' concern about health, the children's health condition, level of the children's concern about health, the children's satisfaction level with their bodies, dietary efficiency feeling, exercise efficiency feeling, social efficiency feeling, personal hygiene, dietary habit, exercise habit, prevention of infectious diseases, prevention of accident, and mental health. From the results of this study, it is clear that obese children's self-efficiency feeling is closely related with health promotion behavior. Therefore, it is necessary to strengthen children's self-efficiency feeling in order to make children control efficiently obesity for themselves.