• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.5
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• pp.253-264
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• 2008

Cyclic delay diversity (CDD) is considered a simple approach to exploit the frequency diversity, to improve the system performance in orthogonal frequency division multiplexing (OFDM) systems. Also, the linear precoding technique can significantly improve the performance of communication systems by exploiting the channel state information (CSI). In order to achieve enhanced performance, we propose applying linear precoding to the conventional CDD-OFDM transmit diversity schemes over Rayleigh fading channels. The proposed scheme works effectively with the accurate CSI in time-division-duplex (TDD) OFDM systems with CDD, where the reciprocity is assumed instead of channel state feedback. For a BER of $10^{-4}$ and the mobility of 3 km/h, simulation results show that a gain of 6 dB is achieved by the proposed scheme over both flat fading and Pedestrian A (Ped A) channels, compared to the conventional CDD-OFDM system. On the other hand, for a mobility of 120 km/h, a gain of 2.7 dB and 3.8 dB is achieved in flat fading and Vehicular A (Veh A) channels, respectively.

• Korean Journal of Veterinary Service
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• v.37 no.2
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• pp.105-110
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• 2014

Porcine epidemic diarrhea virus (PEDV) is the causative agent of porcine epidemic diarrhea (PED) and causes a considerable economic loss in swine industry. In this study, the virucidal efficacy of the disinfectant composed to n-alkyl-dimethyl-benzyl-ammonium chloride (n-ADBAC) was investigated against PEDV. A virucidal efficacy was determined with the viability of PEDV contacted with the disinfectant in Vero cells. The disinfectant and PEDV were reacted on the hard water (HW) or organic matter suspension (OM) condition. On HW condition, PEDV was inactivated with 50 fold dilutions of the disinfectant. When the antiviral effect on OM condition was evaluated, the antiviral activity of the disinfectant showed on 10 fold dilutions against PEDV. As the disinfectant possesses the virucidal efficacy against PEDV, the disinfectant solution can be used to limit the spread of animal viral diseases.

• Journal of the Korean Graphic Arts Communication Society
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• v.28 no.2
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• pp.101-116
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• 2010

Last printing market is changing to high-quality color prints for web offset printing. But, color image reproduction based on the relative sheet-ped printing compared to the way, web offset printing are falling. Moreover, it's difficult to maintain the quality of the web offset print. The reason is the worker's decision to rely on. Therefore, the quality of prints was no difference in uniformity and objectivity. We have thought the reason, that the physical properties of inks such as fluidity, viscosity and tack. In addition, varies depending on the physical properties of paper, such as thickness, smoothness, roughness and porosity. Therefore, we studied the properties of ink and paper on the relations between the properties used IGT printability tester. This study of domestic web offset printing inks and papers on the relationship between physical properties and printability were studied. So, to improve printability will be used as the basis resources for web offset printing.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.236-244
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• 2008

The evolution and application of RFID technologies have been at the forefront of allowing aviation industries to improve the quality of aircraft maintenance and air cargo handling. However, safety problems in airplane operation are arising from the hazards of frequencies transmitted due to RFID systems. Though the intensities of frequencies back-scattered from the tags are very weak, some malfunctions are anticipated due to induction coupling on aircraft wiring. Therefore, safety assessment such as electromagnetic compatability should be accomplished upon aircraft critical and essential equipments before installations.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.219-230
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• 2003

Porcine epidemic diarrhea virus(PED), a member of Coronaviridea, is the etiological agent of enteropathogenic diarrhea in swine. The purpose of this study was to investigate genetic characteristic of PEDV isolated in Korea. Nucleocapsid(N) gene and membrane (M) gene of recent Korean PEDV strains isolated in 2001 were amplified, cloned, sequenced and analyzed. N gene of seven Korean PEDV field isolates bad 94.5% to 99.4% nucleotide and 92.4% to 99.4% amino acid sequence homology each other. Nucleotide and amino acid sequences of Korean field PEDVs were different from published foreign PEDVs, showing 95.1% to 98.0% nucleotide and 93.5% to 97.6% amino acid sequence homology. By phylogenetic tree analysis on based nucleotide sequences, PEDVs were clustered into four groups. By phylogenetic tree analysis based on amino acid sequences. PEDVs were clustered into five groups. M gene of our Korean PEDV field isolates had 99.6% to 100% nucleotide and 98.7% to 100% amino acid sequence homology each other. Nuclotide and amino acid sequences of Korean field PEDVs were different from published foreign PEDVs, showing 98.5% to 98.8% nucleotide and 97.3% to 97.8% amino acid sequence homology. By phylogenetic tree analysis based on nucleotide and amino acid sequences, PEDVs were clustered into two groups which were Korean PEDV isolate group and foreign PEDV isolate group.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.265-274
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• 1998

In order to attain a sustained release at targeted organs in a prolonged time which can reduce the side effects and maximize the therapeutic effect, aclarubicin (ACL) was entrap ped into liposomes of different lipid compositions using Microfluidizer, and dry liposomes were prepared by lyophilization. The dry aclarubicin-entrapped liposomes were evaluated in terms of mean particle size and size distribution, entrapment efficiency and in vitro drug release profile. The Entrapment efficiency of liposome, when the concentration of aclarubicin and lipid were 0.5 to 1.0mg/ml and $200{\mu}mol$/ml, respectively, was over 80% using Microfluidizer, in contrast to 70% of entrapment efficiency using hand-shaking method. Mean particle size and size distribution of aclarubicin-entrapped liposomes of various lipid compositions did not change considerably by the freeze drying. The range of particle size was between 80 and 200nm. Among aclarubicin-entrapped liposomes, ACL-liposome of PC/DPPC/CH0L/TA displayed the most significant sustained release. The addition of DPPC appeared to be favorable for the control of release. In general, aclarubicin entrapped in liposomes was less stable than free aclarubicin either in pH 7.4 phosphate buffer or in human plasma. Formulation I($t_{1/2}$, 20.3 hr) devoid of lipid additive was the most unstable in the phosphate-buffer solution while formulation II($t_{1/2}$, 40.7 hr) with cardiolipin was the most stable. Half lives of aclarubicin-entrapped liposomes in human plasma were 43.2, 50.7, 35.9 and 35.3 hr for formulation I. II, III and IV, respectively, in contrast to 57.8 hr for free aclarubicin.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.3
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• pp.224-236
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• 2002

In this paper, a comparative study on the performance of two-phase and three-phase randomized pulse position PWM scheme for mitigation of audible switching acoustic noise in motor drives is done. In the randomized Pulse Position PW, each of two-Phase or three-phase PWM Pulses is located randomly in each switching interval. Simulation and experimental efforts were executed to investigate the spread effects of Power spectra of inverter output voltage, waveforms of ripple current and audible switching acoustic noise. As results, two-phase RP% scheme is more effective from the viewpoint of switching loss and ease of implementation while the three-phase RPWM scheme is more effective from the viewpoint of the spread effects of power spectra. Also, from the view point of the audible switching acoustic noise in motor drives, two-phase and three-phase RPW schemes are nearly the same.

• Korean journal of food and cookery science
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• v.7 no.2
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• pp.89-95
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• 1991

The effects of lactic acid bacteria on the chemical and microbial changes of fermented kimchi at various temperatures were studied. Kimchi was homogenized and was sterilized by ultra violet (UV), then Lactobacillus plantarum, Leuconostoc mesenteroides, Pediococous acidilactici, Lactobacillus brevis and the mixture of these bacteria inoculated on sterilized kimchi, respectively. The measurement of alcohol by gas chromatography, and changes of sugar content and total viable count were investigated and palatability test was carried while inoculated kimchi was fermented at $30^{\circ}C$, $21^{\circ}C$ and $7^{\circ}C$. Ethyl alcohol was detected by GC in sample I (original Kimchi homogenate), III(inoculated Leu. mesenteroides), V(inoculated with Lac. brevis), then especially, more content were detected at $14^{\circ}C$. Sugar content reduced in accordance with fermentation proceeding. Total viable count increased at early fermentation stage, but thereafter decreased slowly. In the result of palatability test, sample I was the highest at all temperatures, sample III and IV (inoculated with mixed lactic acid bacteria) was the following in that kimchi odor and taste and the temperature.

• Korean Journal of Veterinary Research
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• v.48 no.2
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• pp.167-174
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• 2008

Lactic acid bacteria have been reported their beneficial roles on host including reduction of infectious diarrhea problems. In this study, preventive effect of Lactobacillus (L.) reuteri HY25101 and L. johnsonii HY25103 on porcine epidemic diarrhea virus (PEDV) was investigated in suckling piglets. Two groups of one day old PEDV naïve piglets were orally administered L. reuteri HY25101 and L. johnsonii HY25103 for three days respectively before challenge with lethal dose of PEDV. In second experiment, passive immunized one day old piglets using colostrums containing PEDV specific IgA were used. The survival rates of the L. reuteri HY25101 administered group were significantly higher than that of L. johnsonii HY25103 administered group and viral shedding was rapidly diminished in L. reuteri HY25101 administered group. Interestingly piglets born from the sow immunized with attenuated PEDV vaccine were not completely protected from PEDV challenge, however coadministeration of L. reuteri HY25101 and colostrums containing PEDV specific IgA were more effectively prevent PEDV infection. These results suggested that dietary treatment using L. reuteri HY25101 could reduce diarrheal problem and mortality rate caused by PEDV in suckling pigs. In addition, L. reuteri HY25101 could be used as one of effective compensation treatment with attenuated live vaccine for PED.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.764-771
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• 2012

Direct and maternal genetic heritabilities and their correlations with body weight at 5 stages in the life span of purebred Berkshire pigs, from birth to harvest, were estimated to scrutinize body weight development with the records for 5,088 purebred Berkshire pigs in a Korean farm, using the REML based on an animal model. Body weights were measured at birth (Birth), at weaning (Weaning: mean 22.9 d), at the beginning of a performance test (On: mean 72.7 d), at the end of a performance test (Off: mean 152.4 d), and at harvest (Finish: mean 174.3 d). Ordinary polynomials and Legendre with order 1, 2, and 3 were adopted to adjust body weight with age in the multivariate animal models. Legendre with order 3 fitted best concerning prediction error deviation (PED) and yielded the lowest AIC for multivariate analysis of longitudinal body weights. Direct genetic correlations between body weight at Birth and body weight at Weaning, On, Off, and Finish were 0.48, 0.36, 0.10, and 0.10, respectively. The estimated maternal genetic correlations of body weight at Finish with body weight at Birth, Weaning, On, and Off were 0.39, 0.49, 0.65, and 0.90, respectively. Direct genetic heritabilities progressively increased from birth to harvest and were 0.09, 0.11, 0.20, 0.31, and 0.43 for body weight at Birth, Weaning, On, Off, and Finish, respectively. Maternal genetic heritabilities generally decreased and were 0.26, 0.34, 0.15, 0.10, and 0.10 for body weight at Birth, Weaning, On, Off, and Finish, respectively. As pigs age, maternal genetic effects on growth are reduced and pigs begin to rely more on the expression of their own genes. Although maternal genetic effects on body weight may not be large, they are sustained through life.