• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.5
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• pp.872-882
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• 1994

In this paper, the Low Noise Amplifier(LNA) is designed and fabricated to include a band pass filter characteristics considering the antenna system characteristics according to the transmitting and receiving signal level of communication satellite transponder. As an example, a 2-stage low noise amplifier and a 4-stage amplifier and designed, fabricated and measured at 14,0~14.5GHz of receiving frequency band. This fabricated LNA has shown the gain with very good flatness within pass-band, and its gain decreases rapidly out of band resulting in supperssion of the transmitting signal power leakage. It has shown the 20.3dB +- 0.1dB of pass-band gain, the 1.44dB +-0.04dB of noise figure and the 14dB rejection out of band(12.25~12.75GHz). The gain flatness, noise figure and group delay of this 2-stage LNA satisfactorily met the simulation results. And the fabricated 4-stage amplifier has shown the more than 42dB of pass-band gain, the +-0.25dB of flatness and the 28dB of the rejection effect for transmitting power leakage. The 2-stage LNA and 4-stage amplifier, in this paper, will bring a design margin for the input filter and also result in the system cost reduction.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.393-400
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• 2015

The purpose of this study to examine the effect of intermittent fasting and resistance exercise on sex hormone and glucose metabolism of middle-aged women for 12 weeks. The two groups classified that one group(EG) was done intermittent fasting and resistance exercise both, the other group(CG) was controled. The group of EG was applied doing intermittent fasting 1 time for 24 hours a week, and doing resistance exercise 3 times for 60 minutes a week. The intensity of the exercise was 60%. Each measurement variable measured before and after 12 weeks to investigate the effect. During this study got the result with this step. First, EG have shown small interaction with sex hormone. Second, EG have shown small interaction with resistance exercise. Therefore, this study give us positive result to effect of intermittent fasting and resistance exercise on sex hormone and glucose of middle-aged women for 12 weeks. However, it has limitation to verify effect of intermittent fasting and resistance exercise.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.367-372
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• 2015

This study was aimed at determining the antioxidant and antimicrobial effects of solvent extracts from Asparagus cochinchinensis. The Asparagus cochinchinensis was extracted with water, methanol, ethanol, n-hexane, dichloromethane, ethyl acetate, and ether. The antimicrobial activity of these extracts was determined by modified well diffusion methods against 4 species of respiratory disease bacteria (Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis, and Pseudomonas aeruginosa). In addition, the amount of total polyphenol and flavonoid content, and antioxidant activity was evaluated. Ethyl acetate extract of A. cochinchinensis exhibited higher antimicrobial activity against tested microorganisms than water, methanol, ethanol, n-hexane, dichloromethane, and ether extracts. For antioxidant activity, the ethyl acetate extract of A. cochinchinensis exhibited a notable effect on the scavenging of superoxide against DPPH ($IC_{50}=3.81mg/ml$). Finally, the total polyphenol and flavonoid contents were $14{\pm}0.7mg/g$, and $0.50{\pm}0.13mg/g$, respectively. These results can be regarded as basic research into A. cochinchinensis for the prevention of respiratory diseases. The results indicate that A. cochinchinensis may be utilized as a nutraceutical for respiratory diseases when the physiologically active substances of A. cochinchinensis are increased by further study.

• Microbiology and Biotechnology Letters
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• v.40 no.1
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• pp.39-42
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• 2012

A new method for the high throughput screening of antagonistic substances against rice pathogens using rice leaf explants was developed. This method can be used to confirm the activities of any compound or mixture suppressing rice bacterial blight (BB) before field tests. Xanthomonas oryzae pv. oryzae (Xoo) culture medium was distributed in 96 well plates with equally sized explants and the active compounds were added to the wells. The strength suppressing BB was converted into an area percent of the lesion on the rice explants. The explants under BB suppressing activity remained uninfected maintaining their actual green color, while infected explants exhibited pale yellow-colored lesions. Based on the results, this method seems to be faster and easier, dose-dependent, and can be performed all-at-once with a small amount of unspecified compounds. This method also has the potential to be applied to inspection activities for the suppression of other waterborne crop diseases.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.61-67
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• 2006

We examined seedlings of two species (Ilex rotunda and Illicium anisatum) which have a different level of shade tolerance and raised them under different light regimes (full sunlight and 50% shading). After 12 months, we investigated chlorophyll content (Chl. a, Chl. b and Chl. a+b), photosynthetic systems (photosynthetic rate, light compensation point, dark respiration rate and quantum yield), intercellular $CO_2$ concentration and water use efficiency to show acclimation reaction to different light conditions. Seedlings grown under full sunlight showed lower chlorophyll content than those in the shading regime. There was a significant difference between the full sunlight and shade treatments in I. anisatum (shade tolerance species). I. rotunda (intermediate species) showed high photosynthetic rate and water use efficiency over PPFD $1000\;{\mu}mol\;m^{-2}s^{-1}$ to full sunlight. Also, I. anisatum grown under full sunlight showed lower photosynthetic rate and water use efficiency over a range of all PPFD. This result showed that I. rotunda has a more flexible reaction system than that of I. anisatum.

• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.456-460
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• 2011

Recently, the size of currently-researched components and devices reduces nano-scale. Thus, it is important and emphasizes the analyses of physical properties in nano scale. Especially, the mechanical properties are not over micro-scale components but nano-scale components with different characteristics that has been reported. However, most analytical methods for currently studying in nano-scale are related to spectroscopy and electronics, affected the limitation of viewing size that these methods give only average information. In this research, the representative nanotribology analyses, nano-indenter study the physical and mechanical properties of W-N thin film for nano region and nano depth within nano-scale that the thickness of W-N diffusion barrier has less than tens of nanometers. The Scanning probe microscopy (SPM) study the surface image. From these results, the hardness of W-N thin film underneath the nano-surface decreased from 57.67 GPa to 9.1 GPa according to the increase of nitrogen gas flow. The elastic modulus of W-N thin film underneath the nano-surface also decreased from 575.53 GPa to 178.1 GPa.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.31-37
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• 2018

Campylobacter jejuni is an important food-borne pathogen causing gastroenteritis in human. We isolated 208 strains of Campylobacter jejuni from 430 diarrhea patients and food employees with 17 food-poisoning outbreaks between 2014 and 2016 in Gyeonggi area. The strains were tested for genetic relationship and the genotype distribution using PFGE and multiplex-PCR typing. Among the 47 Penner-serotypes known for C. jejuni, it was identified as a genotype consisting of 35 genotypes by multiplex-PCR typing and represented 7 genotypes (HS2, HS4A, HS8, HS15, HS29, HS41, and HS53) in the selected strain. From the PFGE analysis of 11 food-poisoning outbreaks, 5 group of PFGE profile were obtained, and genetic similarity in these clusters ranged from 61.8 to 66.6%. This study examines the genetic diversity of C. jejuni that have been separated in the Gyeonggi area through various genetic analysis methods and identifies the correlation between strains in patients who have been infected with the disease in the future.

• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.180-189
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• 2017

Genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by global agricultural companies. Until now, GM crops have not been cultivated commercially in Korea. Commercialization of GM crops requires a compulsory assessment of environmental risk associated with the release of GM crops. This study was conducted to evaluate the frequency of pollen mediated gene flow from Bt transgenic rice (Agb0101) to japonica non-GM rice (Nakdongbyeo), indica non-GM rice (IR36), and weedy rice (R55). A total of 729,917, 596,318 and 230,635 seeds were collected from Nakdongbyeo, IR36, and R55, respectively, which were planted around Agb0101. Selection of the hybrids was determined by repeated spraying of herbicide and Cry1Ac1 immunostrip assay. Finally, the hybrids were confirmed by PCR analysis using specific primer. The hybrids were found in all non-GM rice and out-crossing ranged from 0.0005% at IR36 to 0.0027% at Nakdongbyeo. All of hybrids were located within 1.2 m distance from the Agb0101 rice plot. The meteorological elements including rainfall and temperature during rice flowering time were found to be important factors to determine rice out-crossing rate. Consideration should be taken for many factors like the meteorological elements of field and physiological condition of crop to set up the safety management guideline to prevention of GM crops gene flow.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.359-367
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• 2022

The purpose of this study was to explore the effect of learning effects by type on college life satisfaction for college students. A total of 250 copies of the survey were distributed, and a total of 219 copies were used for analysis except for 31 copies, excluding questionnaires with many poor or missing questions. The learning effect according to the socio-demographic characteristics of college students showed a significant difference in the form of cohabitation, and it was found that the learning effect was high in the order of alone and friends. Perceptual learning showed significant differences in the form of cohabitation, and it was found that perception learning was high in the order of alone, friends, and seniors and juniors. Cognitive learning showed significant differences in the form of cohabitation, and cognitive learning was found to be high in the order of friends, alone, and seniors and juniors. There was a significant difference in college satisfaction with the type of cohabitation, and it was found that college satisfaction was high in the order of alone, seniors and juniors, and friends. Finally, the higher the discovery learning, perceptual learning, and cognitive learning, the higher the college life satisfaction, and among them, discovery learning was found to have a great influence on college life satisfaction. Overall, the university should provide an environment where students can freely move between individuals and communities and live their university life. In addition, in preparation for problems occurring in the community, it will be necessary to activate the related counseling room.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.1
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• pp.37-45
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• 1979

Experiments were conducted to determine the physicochemical properties for 1.382 tested wheat harvested in 1977. All the tested wheats had a milling yield rate of 49 to 71.5 percent. The cross combination involving S.son, Caprock and CI 12703 was generally the higher in flour yield-Flour protein content ranged from about 7 percent up to about 17 percent and sedimentation values ranged from below 20 cc to 70 cc. The cross combinations involving Bb #1 gave higher protein content and higher sedimentation values than the other combinations. The distribution of the Pelshenke value was from less 20 min. to more than 180 min. Specific sedimentation values of the 329 tested wheats showed 8.1 percent to be hard quality, while 54.4 percent were of soft quality. Intermediate wheats accounted for 37.5 percent. The lines having high milling yield rate, protein content and sedimentation value from the 329 tested wheats were Strampelli \times 69D-3607/Jogwang. S.son \times Caprock. Suweon #185 \times Toropi and Suweon #185 \times Ciano. The varieties or lines including Pribog, CI 14496 and Sturdy \times Scout/ Strampelli \times Bb-Cno showed high milling yield but low protein content and low sedimentation values. being under 9 percent and 30 cc respectively.