• Journal of Embryo Transfer
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• v.12 no.1
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• pp.27-36
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• 1997

The studies were carried out to investigate the effects of co-culture with cumulus cells and oviduct epithelial cells on the in vitro fertilization and cleavage rate of bovine follicular cocytes and to determine the optimum thawing temperature and equilibration time on in vitro developmental rate of frozen bovine embryos. The ovaries were obtained from slaughtered Korean native cows. The follicular oocytes were cultured in TGM-199 medium containing 10 IU /ml의 PM SG, 10 IU /ml의 hCG, ip g/ml의 $\beta$-estradiol and 10% FCS for 24~48 hrs in incubator with 5% $CO_2$ in air at 38.5$^{\circ}C$. The bovine embryos following dehydration by cryoprotective agents and a various concentration of sucrose were directly plunged into liquld nitrogen and thawed in 3$0^{\circ}C$ water. Survival rate was defined as developmental rate on in vitro culture or FDA-test. The results are sunanarized as followes :1. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with cumulus cells in TCM499 medium were 75.0~76.8% and 17.3~27.6%, respect-ively. And in-vitro fertilization rates of cumulus-enclosed oocytes(55.4%)were significantly(p<0.05) higher than cumulus-denuded oocytes (23.1%). 2. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with l$\times$ l04cells /ml, 1 x l06cells /ml, lx l08cells /ml and 1 x l015cells /ml oviduct epithelial cells in TCM-199 medium were 74.5~77.8% and 15.7~21.20 respectively.3. The in-vitro fertilization and in vitro developmental rates of bovine oocytes cocultured in '1CM-199 media containing PMSG, hCG, PMSG+hCG. PMSG+$\beta$-estradiol, hCG+$\beta$-estradiol 0 to 40 hrs after insemination were 74.0~77.4% and l8.9~23.l%, re-spectiv ely.4.The survival rates of bovine embryos thawed after rapid freezing in the freezing medium containing a various concentration of sucrose added 1.5M and 2.OM glycerol,DMSO and propanediol were 23.5~31.4% and 20.6~34.l%, respectively. 5. The temperature thawed at 3$0^{\circ}C$ after rapid freezing of bovine embryos resulted in a significantly higher embryos survival rate than did at 2$0^{\circ}C$ and 35$^{\circ}C$.6. The equilibration time on the survival rates of bovine embryos was attained after short period of time(2.5~5 min.) in the freezing medium higher than long period of time (10~20min.). (Key words : bovine embryos, co-culture, freezing, in vitro development)

• Korean Journal of Animal Reproduction
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• v.5 no.1
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• pp.26-30
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• 1981

The purpose of this study was to measure the serum content of progesterone, estradiol 17${\beta}$ and cortisol. Blood samples collected from day 20 prepartum to day 20 postpartum in 8 sows. Progesterone and estradiol-17${\beta}$ were assayed by radioimmunoassay methods and cortisol was determined by competitive protein-binding methods. Progesterone levels began to decline on day -4, reached 1.9ng/ml by day +2 and remained quite constant thereafter. Progesterone levels remained fairly constant(18.4 to 20.0 ng/ml) from 20 to 6 days before parturition. Estrdiol-17${\beta}$ increased from 205 pg/ml at day 6 prepartum to 425 pg/ml at the time of parturition. Cortisol reached a peak level of 86.5 ng/ml at day 0.

• Korean Journal of Microbiology
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• v.11 no.3
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• pp.129-133
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• 1973

The authors have investigated about the microbial contamination of goods which is a criterion of hygienic control. Conducting on investigation, a special attention has been paid on the rate of microbial contamination in the goods, especially in manufacturing process of the softdrink. The authors also made an experiment on total microbes which is the criterion of contamination in each step of the process and in raw materials together with materials to be used for subdividing. Results obtained were as follows : 1) The orgin of microbial contamination was found in bottle cap and in tap water, that is, there appeared 9 colony per ml in bottle cap and 31-74 colony per ml in tap water, respectively. 2) It was found that microbial contamination are 4 colony per ml in average through year. However, it appeared 1 colony per ml in winter and 8 colony per ml in summer. 3) Coliform groups are not detected in goods through a year. 4) There was no variation in number of total microbes after ion exchange resin passage in purification process of tap water. 5) The number of microbes in goods are decreased when the raw materials are treated in high temperature short time (HTST) sterilization.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.585-590
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• 1998

To renew interest in Chrysanthemum boreale as a traditional food material, response surface methodology was used for optimizing extraction conditions and monitoring physicochemical properties of ethanol extracts from Chrysanthemum petal. The phenolic compounds of ethanol extracts were minimized in 87ml/g(solvent per sample), 21%(ethanol concentration), and 15 hours(extraction time). The physicochemical properties of ethanol extracts were maximized in the conditions of 115ml/g, 98% and 16 hours on yellow color intensity, 143ml/g, 75% and 19 hours on carotenoid content, and 148ml/g, 53% and 18 hours on soluble solid content. Optimum ranges of extraction condition for physicochemical properties of Chrysanthemum boreale were 130~150ml/g, 70~85% and 20~28 hours, respectively. Predicted values at the optimum extraction condition were in good agreement with experimental values.

• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.90-93
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• 2010

This paper shows various perfermance analysis utilizing STC(Space Time Coding) in MIMO mobile communication by WiBro system environments. In this paper, 3 algorithm which are SM method, ML (Maximum Likelihood) and ZF(Zero Forcing) algorithm use for perfermance analysis. From the various simulation result, it is confirm that ZF method is superior compare than STC and ML method.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1167-1174
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• 2022

Cast austenitic stainless steels (CASSs) are widely used as structural materials in the nuclear industry. The main drawback of CASSs is the reduction in fracture toughness due to long-term exposure to operating environment. Even though ultrasonic non-destructive testing has been conducted in major nuclear components and pipes, the detection of cracks is difficult due to the scattering and attenuation of ultrasonic waves by the coarse grains and the inhomogeneity of CASS materials. In this study, the ultrasonic signals measured in thermally aged CASS were discriminated for the first time with the simple ultrasonic technique (UT) and machine learning (ML) models. Several different ML models, specifically the K-nearest neighbors (KNN), Support Vector Machine (SVM), and Multi-Layer Perceptron (MLP) models, were used to classify the ultrasonic signals as thermal aging condition of CASS specimens. We identified that the ML models can predict the category of ultrasonic signals effectively according to the aging condition.

• The Journal of the Acoustical Society of Korea
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• v.25 no.2
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• pp.56-60
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• 2006

Based on the fact that audio signals in the time domain have the generalized Gaussian distribution. an optimal parameter estimation of the ML (maximum likelihood) test based audio watermark decoder. which leads to the minimal bit error rate, is Proposed. Its superiority of performance over the existing estimation and the conventional correlation based decoder is demonstrated experimentally.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.149-152
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• 2002

In this paper, an adaptive interference canceller (AIC) Is applied to the space-time coded DS-CDMA system in fading channels with arrival time difference from multiple transmit antennas In a CDMA system, arrival time difference causes not only inter-antenna and Inter-symbol interference but also multiple-access Interference even in a downlink. To mitigate the effect of the Interferences an AIC and ML decoding joint scheme Is proposed fur a space-time coded DS-CDMA system in which an adaptation process of tile AIC is merged in the Viterbi decoding algorithm. The performance of the proposed receiver is evaluated for the system with two transmit antennas. It is shown that the proposed receiver achieves significant performance improvement over the ML decoding receiver without the AIC

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.64-71
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• 1981

The present study was carried out to study the serum concentration of peptide and steroid hormones in puerperal sow. Eight crossbred sows were used for collection of blood samples from day 20 prepartum to day 20 postpartum. FSH, LH, prolactin, estradiol-$17{\beta}$, progesterone and cortisol were assayed by radioimmunoassay methods. The mean serum FSH did not vary during the puerperal period and ranged from $8.1{\pm}1.8mIU/ml$ to $9.0{\pm}2.3mIU/ml$. LH concentrations increased from $2.6{\pm}0.3mIU/ml$ at day 20 prepartum to $3.9{\pm}1.1mIU/ml$ at the time of parturition, reached $3.2{\pm}0.9mIU/ml$ by day+2 and remained quite constant therafter. Prolactin reached a peak mean level of $68.5{\pm}9.5ng/ml$ at day 0. Estradiol-$17{\beta}$ increased from $205.0{\pm}29.5pg/ml$ at day 6 prepartum to $425.0{\pm}35.0pg/ml$ at the time of parturition. Progesterone remained fairly constant ($18.4{\pm}1.6$ to $20.2{\pm}2.1ng/ml$) from 20 to 6 days before parturition, began to decline on day-2, reached $0.9{\pm}0.3ng/ml$ by day+2 and remained quite constant thereafter. Cortisol reached a peak level of $86.5{\pm}10.5ng/ml$ at the day 0.

• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.87-99
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• 2013

Waste paper stands for the major biodegradable organic fraction of most of municipal solid waste. The potential of waste paper for glucose production was investigated in this current work. The pretreatment was accomplished by first subjecting waste paper to disintegration time (30 s), followed by ink removal of disintegrated waste paper using an deinking agent. Concentrated acid hydrolysis of waste paper with sulfuric acid was optimized to maximize glucose conversion. The concentrated acid hydrolysis conditions for waste paper (disintegrated time: 30 s, deinking agent loading : 15 ml) were optimized by using central composite design and response surface methodology. The optimization process employed a central composite design, where the investigated variables were acid concentration (60~80%), loading sulfuric acid (1~5 ml) and reaction time (1~5 h). All the tested variables were identified to have significant effects (p < 0.05) on glucose conversion. The optimum concentrated acid hydrolysis conditions were acid concentration of 70.8%, loading sulfuric acid of 3.2 ml and a reaction time of 3.6 h. This research of concentrated acid hydrolysis was a promising method to improve glucose conversion for waste paper.