• Journal of Digital Contents Society
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• v.5 no.3
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• pp.187-191
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• 2004

Rapid time variations of the mobile communication channel have a dramatic effect on the performance of multi-carrier modulation. This paper analyzed the bit error rate (BER) performance for multi-carrier code division multiple access (MC-CDMA) network, and derived the equivalent signal-to-total noise plus interference(SNIR) of MC-CDMA system in the reverse link, the performance of MC-CDMA/BPSK signal is evaluated taking into account the fraction of partial-band interference and interference power. and the effect of partial-band interference is comprehensively studied in order to further improve the Qos of multi-carrier multimedia system.

• Nuclear Engineering and Technology
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• v.21 no.3
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• pp.216-222
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• 1989

The MC-50 cyclotron at Korea Canter Center Hospital is now operational for neutron therapy and medical radioisotope production. Design features, mechanical structures and operating characteristics of the MC-50 are described in this paper. Optimum operating condition for this cyclotron has been determined by the repetitive running, and the performances of the internal beam have been investigated through the measurements of intensity and spatial distribution of the internal beam as a function of the radius of the cyclotron. Routinely, the 40 $\mu$A of 50 MeV protons have been obtained at first Faraday cup with a extraction efficiency of 61%.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.811-816
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• 2022

This work presents the methodology used to expand the capabilities of the Monte Carlo code OpenMC for the calculation of reactor kinetic parameters: effective delayed neutron fraction β_eff and neutron generation time L. The modified code, OpenMC(Time-Dependent) or OpenMC(TD), was then used to calculate the effective delayed neutron fraction by using the prompt method, while the neutron generation time was estimated using the pulsed method, fitting Λ to the decay of the neutron population. OpenMC(TD) is intended to serve as an alternative for the estimation of kinetic parameters when licensed codes are not available. The results obtained are compared to experimental data and MCNP calculated values for 18 benchmark configurations.

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.3
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• pp.31-37
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• 2014

Purpose : Delayed onset muscle soreness(DOMS) is a common problem that can interfere with rehabilitation as well as activities of daily living. The purpose of this study was to compare the effect of both trascutaneous electrical nerve stimulation(TENS) Micro current(MC) and only normal Therapy on Delyed Onset Muscle Soreness(DOMS). Method : The Methods ten untrained and male volunteer subjects were randomly assigned to one of two treatment groups: 1) a group that received TENS (60Hz) MC($60{\mu}A$, 3pps) a control group that received no MC treatment. Subjects performed repeated eccentric exercise of the non-dominant forearm flexor muscle with submaximal intensity by the simply designed eccentric exercise devices. Treatments were applied after 24hours and 48hours. Subjects attended on two consecutive days for treatment and measurement of paining(visual analogue scale: VAS) and CK(Creatine kinase) on a daily basis. Measurements were taken after treatment. Results : 1) There were no significant differences between TENS and MENS by two-way repeated ANOVA. The Results that t-test for VAS revealed significant differences within TENS group. 3) The t-test for VAS, and Creatine Kinase of time revealed significant differences within MC group. Conclusion : These findings suggest that both TENS and MENS had effect on DOMS.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.2
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• pp.241-246
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• 1989

Mold development on leaf tobacco(Flue-cured, var. NC 82) during the storage was examined according to the initial moisture content(MC) of the tobacco. The initial moisture content of the leaf tobacco was controlled as 12,14,16% after redrying. Those were packed in cardboard boxes and stored in a warehouse. Samples were taken monthly from June of 1988 through August of 1989 and were evaluated for mold development (colony count) and MC. The moisture content change in the leaf tobacco of 12, 14 and 16% initial MC was in the range of 11.1-13.3, 12.8-15.3 and 14.9-16.7% and the mean number of colonies from them were 1.4$\times$102, 1.0$\times$102, and 4.0$\times$102 colonies per gram of tobacco, respectively, however mold-damaged leaf tobacco other than the treatments was occasionally observed to have the colony number as high as 2.3$\times$105 colonies per gram of tobacco. In the meantime, the leaf tobacco was stored at 6 relative humidity levels at $25^{\circ}C$ in laboratory test. Leaf tobacco of 15.0-16.4% MC was maintained without the mold-damage after 80 days of storage whereas those of 19.9, 21.3, 25.5 and 27.1% MC became moldy after 50, 15, 11 and 6 days of storage, respectively.

• Journal of Life Science
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• v.30 no.1
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• pp.58-63
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• 2020

This study was conducted to examine association between melanocortin-4-receptor (MC4R) genotypes and fatty acid (FA) composition in an F₂ intercross between Duroc and Jeju (South Korea) Native pigs (JNP). Fourteen FA composition traits were measured in more than 290 F₂ progeny population produced between Duroc and JNP. All experimental pigs were successfully genotyped for the MC4R c.1426A>G (p.Asp298Asn) single nucleotide polymorphism (SNP) by using Taq I PCR-RFLP methods. We detected three MC4R genotypes, AA, AG, and GG with 0.299, 0.542, and 0.159 genotype frequencies, respectively. The MC4R AA genotype animals showed higher levels in palmitic acid (C16:0, p<0.05), stearic acid (C18:0, p<0.01), eicosenoic acid (C20:1n9, p<0.05), saturated fatty acid (SFA, p<0.01) than GG homozygotes, respectively. Whereas MC4R GG genotype showed higher values in linoleic acid (C18:2n6, p<0.001), linolenic acid (C18:3n3, p<0.001), linolenic acid (C18:3n6, p<0.001), arachidonic acid (C20:4n6, p<0.001) and unsaturated fatty acid (USFA, p<0.01) than AA pigs, respectively. The MC4R GG genotype was associated with increasing USFA and decreasing SFA in the F₂ progeny population produced between Duroc and JNP. Our finding suggests that the MC4R polymorphisms can be used as a valuable genetic marker for Duroc and JNP breeding programs to improve meat quality and to control FA compositions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1471-1479
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• 1999

This paper presents an adaptive beamforming algorithm for an MC-CDMA system with an adaptive array antenna. By employing an antenna array at the receiver of an MC-CDMA system, the performance of an MC-CDMA system, which is known to be effective for high data rate transmission due to its robustness to multipath fading and its simplicity for using a simple one-tap equalizer, is shown to be significantly improved. The proposed algorithm for adaptive beanforming in an MC-CDMA system is derived by (1) calculating the error signals between the pilot symbols of desired user and the received pilot signals in frequency domain, (2) transforming the frequency-domain error signals into time-domain error signals, (3) updating the filter coefficients of the adaptive beamformer in the direction of minimizing the MSE. Convergence behavior and performance improvement of the proposed approach are demonstrated through computer simulation by applying it to the conventional MC-CDMA system.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.521-526
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• 2007

In this study, we prepared methyl cellulose (MC) and hydroxypropylated methyl cellulose (HPMC) films with polyethylene glycol (PEG) or polyphosphates as elongation enhancing materials, and with lipid layers as moisture barrier materials. We then determined their physical properties and compared the data with target physical properties such as a tensile property of 13.0 MPa, elongation of 130%, and water vapor permeability of $3.47{\times}10^{-2}ng{\cdot}m/m^2{\cdot}s{\cdot}Pa$. The PEG and polyphosphates were required for enhancing elongation, while the coating method seemed better than the emulsion method when applying the lipid layers. With respect to elongation, the MC films were better than the HPMC films.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.300-309
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• 2010

Melamincyanurate(MC), as an non halogen flame retardant are used as the polymer and plastic materials. In this study, melamine and cyanuric acid were used for the synthesis of MC. The optimum condition of synthetic MC were controlled by different molar ratio of melamine to cyanuric acid. MC was modified by coupling reaction with four different agents. The influences of modified MC were based on the coupling agent types. Preparation methods are available to offer the prospect of improved morphology control deposit stability in polyol. The results reveal that glycidoxypropyltrimethoxysilane(GDS) has the best storage stability. The best properties were obtained with melamine and cyanuric acid from 1:1 molar ratio. Modification of MC through coupling agent can efficiently enhanced the deposit stability in polyol up to 30 %.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.249-252
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• 2000

In this paper, the performance of a MC-CDMA system applying adaptive subchannel allocation scheme and M-ary orthogonal signaling is analyzed for forward links in Rayleigh fading channel. In the proposed system, each DS waveform is transmitted over the subchannel having the biggest fading among L subchannels. Assuming M-ary orthogonal signaling and 4 subchannels, the BER of 10$\^$-3/ is satisfied if SNRs are 7.33 ㏈, 5.33 ㏈, and 4.47 ㏈ for k=1, 2, and 3, respectively. Also, SNRs which met BER of 10$\^$-3/ are 1.42 ㏈ and 2.33 ㏈ in L=2 and L=8 as k=1 is increased to k=2. It is shown that the MC-CDMA system has performance improvement as a number of subcarriers and M-ary orthogonal signaling.