• Korean Journal of Fisheries and Aquatic Sciences
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• 제34권5호
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• pp.509-514
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• 2001

Effects of conjugated linoleic acid (CLA), known as an effective anticarcinogen in several animal models, on the tilapia were investigated. The CLA was made from safflower oil by alkaline isomerization method. Isomers in CLA such as cis-9, trans-11 and trans-10, cis-12 occupied over $80\%$, and other isomers was below $20\%$. In experiment, 250 fishes (average weight is 32 g) were divided into 15 fishes per five treatment and triplicate group for 8 weeks: control, $1\%$ CLA, $2.5\%$ CLA, $5.0\%$ CLA, and $10\%$ CLA diets. Daily growth rate and feed coefficiency were measured every week. The most effective diet for the growth rate and feed coefficiency of tilapia was $1.0\%$ CLA diet group. Every two weeks, sampled and determined the contents of CLA in the muscle and liver, After 8 weeks, $1.0\%$ and $10.0\%$ of CLA fed group accumulated the CLA as 41.3 and 180.9 mg/g of fat in their muscle respectively, Also, n-9 and n-3 fatty acid (FA) compositions were almost not changed in the muscle and liver. But n-6 fatty acid was changed according to the contents of fed CLA. The $1.0\%$ CLA fed group was shown the highest contents of n-6 FA and the $10.0\%$ CLA group was shown the lowest contents of n-6 FA.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.249-252
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• 2002

we have studied the characteristics of PHEMT's with gate recess etching method. The DC characterization of PHTMT fabricated with the wide single recess methods is a maximum drain current density of 319.4 ㎃/mm and a peak transconductance of 336.7 ㎳/mm. The RF measurements were obtained in the frequency range of 1~50GHz. At 50GHz, 3.69dB of 521 gain were obtained and a current gain cut-off frequency(f$_{T}$) of 113 CH and a maximum frequency of oscillation(f$_{max}$) of 172 Ghz were achieved from this device. On the other hand, a maximum drain current of 367 mA/mm, a peak transconduclancc of 504.6 mS/mm, S$_{21}$ gain of 2.94 dB, a current gain cut-off frequency(f$_{T}$) of 101 CH and a maximum frequency of oscillation(f$_{max}$) of 113 fa were achieved from the PHEMT's fabricated by the .narrow single recess methods.methods.

• Proceedings of the KIEE Conference
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.88-90
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• 1994

The permanent magnet type stepping motor is used widly for various devices, such as FA and OA machine. Characteristics of the stepping motor is analyzed using permeance method. Static, dynamic and I step response characteristics of PM type stepping motor for idle air valve is discussed.

• Journal of the Korean Association of Geographic Information Studies
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• 제13권2호
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• pp.94-106
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• 2010

Understanding of the amount of energy resources and site selection are required prior to develop Ocean Thermal Energy (OTE). It is necessary to calculate the appearance probability of difference of seawater temperature(${\Delta}T$) between sea surface layer and underwater layers. This research mainly aimed to calculate the appearance probability of ${\Delta}T$ using frequency analysis(FA) and harmonic analysis(HA), and compare the advantages and weaknesses of those methods which has used in the South Sea of Korea. Spatial scale for comparison of two methods was divided into local and global scales related to the estimation of energy resources amount and site selection. In global scale, the Probability Differences(PD) of calculated ${\Delta}T$ from using both methods were created as spatial distribution maps, and compared areas of PD. In local scale, both methods were compared with not only the results of PD at the region of highest probability but also bimonthly probabilities in the regions of highest and lowest PD. Basically, the strong relationship(pearson r=0.96, ${\alpha}$=0.05) between probabilities of two methods showed the usefulness of both methods. In global scale, the area of PD more than 10% was less than 5% of the whole area, which means both methods can be applied to estimate the amount of OTE resources. However, in practice, HA method was considered as a more pragmatic method due to its capability of calculating under various ${\Delta}T$ conditions. In local scale, there was no significant difference between the high probability areas by both methods, showing difference under 5%. However, while FA could detect the whole range of probability, HA had a disadvantage of inability of detecting probability less than 10%. Therefore it was analyzed that the HA is more suitable to estimate the amount of energy resources, and FA is more suitable to select the site for OTE development.

• Journal of the Korean Institute of Intelligent Systems
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• 제19권6호
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• pp.865-871
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• 2009

In this paper, a novel feedback linearization is proposed for discrete-time nonlinear systems described by discrete-time T-S fuzzy models. The local linear models of a T-S fuzzy model are transformed to a controllable canonical form respectively, and their T-S fuzzy combination results in a feedback linearizable Tagaki-Sugeno fuzzy model. Based on this model, a nonlinear state feedback linearizing input is determined. Nonlinear state transformation is inferred from the linear state transformations for the controllable canonical forms. The proposed method of this paper is more intuitive and easier to understand mathematically compared to the well-known feedback linearization technique which requires a profound mathematical background. The feedback linearizable condition of this paper is also weakened compared to the conventional feedback linearization. This means that larger class of nonlinear systems is linearizable compared to the case of classical linearization.

• Asian-Australasian Journal of Animal Sciences
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• 제25권10호
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• pp.1364-1373
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• 2012

Four crossbred (75% Holstein Friesian) lactating dairy cows, with an average live weight of $418{\pm}5$ kg and $36{\pm}10$ d in milk were randomly assigned according to a $2{\times}2$ factorial arrangement in a $4{\times}4$ Latin square design to evaluate the effects of cassava hay (CH) and rice bran oil (RBO) on feed intake, nutrient digestibility, ruminal fermentation, milk yield, and milk composition. Factor A was non-supplementation or supplementation with CH in the concentrate. Factor B was supplementation with RBO at 0% or 4% in the concentrate mixture. The four dietary treatments were (T1) control (Concentrate with non-CH plus 0% RBO; C), (T2) Concentrate with CH plus 0% RBO (CH), (T3) Concentrate with non-CH plus 4% RBO (RBO), and (T4) Concentrate with CH plus 4% RBO (CHRBO). The cows were offered concentrate, at a ratio of concentrate to milk production of 1:2, and urea-lime treated rice straw was fed ad libitum. Urea-lime treated rice straw involved 2.5 g urea and 2.5 g $Ca(OH)_2$ (purchased as hydrated lime) in 100 ml water, the relevant volume of solution was sprayed onto a 100 g air-dry (91% DM) straw, and then covering the stack with a plastic sheet for a minimum of 10 d before feeding directly to animals. The CH based concentrate resulted in significantly higher roughage intake and total DM intake expressed as a percentage of BW (p<0.05). Ruminal pH, $NH_3$-N, BUN and total VFA did not differ among treatments, while RBO supplementation increased propionate, but decreased acetate concentration (p<0.05). Furthermore, the population of total ruminal bacteria was significantly lower on the RBO diet (p<0.05). In contrast, the total ruminal bacteria and cellulolytic bacteria on the CH diet were higher than on the other treatments. Supplementation with CH increased (p<0.05) F. succinogens and R. flavefaciens populations, whereas the populations of B. fibrisolvens and M. elsdenii were increased on the RBO diet. In addition, supplementation with CH and RBO had no effect on milk production and composition in dairy cows, while fatty acid composition of milk was influenced by RBO supplementation, and resulted in significantly lower (p<0.05) concentrations of both short-chain and medium-chain FA, and increased (p<0.05) the proportion of long-chain FA in milk fat, as well as significantly increased cis-9, trans-11 CLA and total CLA. In conclusion, RBO or CH exhibited specific effects on DMI, rumen fermentation, microbial population, milk yield and composition in lactating dairy cows, which were not interactions between CH and RBO in the diets. Feeding lactating dairy cows with RBO could improve fatty acid in milk fat by increasing cis-9, trans-11 CLA.

• Journal of the Korean Applied Science and Technology
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• 제38권6호
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• pp.1476-1484
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• 2021

The purpose of this study was to compare the golf performance on transcranial direct current stimulation(tDCS). Ten collegiate golfers were participated. SAMPutt basic unit was used to analyze the kinematic data of putter head. A putting platform and a tDCS were used for putting tasks. It was performed paired t-test to compare between before tDCS and after tDCS. A significant level of .05 using SPSS 24.0. Face at aim and backswing variables of putter head were significantly different during flat putting. Impact spot of putter head was significantly different during 2° of hook slope. However, there were not significantly different others slope angle. It was found that transcranial direct current stimulation had a positive effect on kinematic variables. Based on these results, further research is needed to confirm the effect of transcranial direct current stimulation on body stability during putting task.

• Steel and Composite Structures
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• 제38권6호
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• pp.617-635
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• 2021

This paper numerically investigated the behavior of built-up square concrete-filled steel tubular (CFST) columns under combined preload and axial compression. The finite element (FE) models of target columns were verified in terms of failure mode, axial load-deformation curve and ultimate strength. A full-range analysis on the axial load-deformation response as well as the interaction behavior was conducted to reveal the composite mechanism. The parametric study was performed to investigate the influences of material strengths and geometric sizes. Subsequently, influence of construction preload on the full-range behavior and confinement effect was investigated. Numerical results indicate that the axial load-deformation curve can be divided into four working stages where the contact pressure of curling rib arc gradually disappears as the steel tube buckles; increasing width-to-thickness (B/t) ratio can enhance the strength enhancement index (e.g., an increment of 1.88% from B/t=40 to B/t=100), though ultimate strength and ductility are decreased; stiffener length and lip inclination angle display a slight influence on strength enhancement index and ductility; construction preload can degrade the plastic deformation capacity and postpone the origin appearance of contact pressure, thus making a decrease of 14.81%~27.23% in ductility. Finally, a revised equation for determining strain εscy corresponding to ultimate strength was proposed to evaluate the plastic deformation capacity of built-up square CFST columns.

• Korean Journal of Plant Resources
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• 제28권5호
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• pp.582-590
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• 2015

In the present study, we investigated the effect of 70% EtOH extract from Hippophae Rhamnoides L. leaves (HRL) on the anti-obesity effect in 3T3-L1 cells. The effects of HRL on lipid accumulation in 3T3-L1 cells were examined using Oil Red O staining. In addition, we examined the gene expression levels by using RT-PCR and western blot. The results of this analysis showed that 100 ㎍/㎖ HRL significantly increased the inhibition of lipid accumulation by 82.25%; significantly decreased the mRNA expression of sterol regulatory element binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding proteins α (C/EBPα), and fatty acid synthase (FAS) in 3T3-L1 cells as well as the stimulated protein expression of AMP-activated protein kinase (AMPK); and suppressed the expression level of PPARγ. These results suggest that HRL can prevent adipogenesis through activation of AMPKα and inhibition of adipogenesis transcription factors.

• Journal of the Korean Society of Food Science and Nutrition
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• 제29권5호
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• pp.957-964
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• 2000

To assess trans fatty acids (tFAs) intake of a girls' high school students in Pusan, dietary history and quantitative food frequency questionnaire (FFQ) were surveyed and analyzed with a total subjects of 274, 268 in summer and winter respectively. It was shown that 38.0% of subjects which was the highest percentage, had snack twice a day in frequency of snack intake. The most favorite snack of subjects was ice cream (46.4%), the preference for milk and dairy products was considerably high. 43.4% of subjects responded to once a month in frequency of dining out. They preferred grilled pork (39.1%), hamburger (36.9%), grilled beef (26.6%) in order. It was also appeared that they preferred fast food. In the case of eating bread, 8.0% of subjects ate bread and margarine, 7.1% butter. Generally, the subjects preferred margarine to butter. tFAs intake for each person per day was $4.24{\pm}0.18\;g$. There was significant difference in tFAs intake according to parents income (p<0.05), frequency of snack intake (p<0.001) and that of dining out (p<0.05). tFAs intake produced naturally (N-tFAs) was $0.86{\pm}0.00\;g$ which corresponded to 20.3% of total tFAs intake per day. tFAs intake produced artificially (H-tFAs) in the process of hardening oil was $3.38{\pm}0.14\;g$, equaled to 79.7% of total tFAs intake per day. There was significant difference between H-tFAs intake for each person per day (p=0.000)