• Journal of the Korean Chemical Society
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• v.26 no.3
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• pp.135-141
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• 1982

The gamma radiolysis of C$O_2$, in the presence of organic additives, was studied at the total absorbed dose of 6.7 Mrad. Considerable quantity of CO was produced by adding these additives to $O_2$, though no CO was found without them. The maximum G(CO) values of 4.1 and 4.6 were obtained by addition of 0.5% methanol and 0.25% ethanol, respectively. The G(CO) values of 6.3 and 8.4 were noted by the addition of 1% acetaldehyde and 1% formaldehyde, respectively. The maximum CO concentration of 0.65% was obtained by the addition of 1% acetaldehyde at the dose of 40 Mrad.

• Korean Journal of Food Science and Technology
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• v.4 no.2
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• pp.95-99
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• 1972

Studies were made to investigate the influence of vacuum packing after irradiating mean doses of gamma ray at freezing temperature $(-20^{\circ}C)$ on the keeping quality and color of raw beef. Fresh round steaks were packaged anaerobically in aluminum foil, and irradiated with 0.25 and 0.5 Mrad followed by storage at $5^{\circ}C$. The shelf life of beef irradiated with 0.5 Mrad could be extended about 10 days longer than unirradiated, and the off-odors was not developed. The discoloration by irradiation was shown, but soon reverted to about 90 percentage myoglobin in 20 hours.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.158-158
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• 2016

본 연구에서는 극치 분포의 오른쪽 꼬리 부분 예측 시 안정적인 확률수문량 산정하는 확률분포형과 매개변수 추정 방법을 평가하기 위해 Monte Carlo 모의를 수행하였다. 수문자료의 빈도해석에 적합한 것으로 알려진 generalized extreme value (GEV), Gumbel (GUM), generalized logistic (GLO), gamma3 (GAM3), normal (NOR), log-normal3 (LN3) 총 6개의 확률분포형을 바탕으로 오른쪽 꼬리 부분의 확률수문량 추정 성능을 모의 실험을 통해 평가하고자 한다. 30년 이상 자료를 보유한 기상청 지점의 지속기간별 연최대값 자료를 분석한 결과를 바탕으로 모분포를 GEV분포로 선정하였으며 평균이 1.0, 표준편차 0.5, 왜곡도 계수는 0.5, 1.0, 2.0, 3.0, 4.0이 되도록 가정하였다. 또한 자료 길이에 따른 성능 평가를 위해 표본 크기 20, 50, 100, 150, 200개에 대해 분석을 수행하였다. 위와 같은 가정으로 총 25종류(왜곡도계수 5개 ${\times}$ 표본 크기 5개)의 발생된 모분포에 6가지의 확률분포형과 3가지의 매개변수 추정방법(모멘트법, 최우도법, 확률가중모멘트법)을 조합한 18가지의 모델을 비교 분석해보았다. 평가방법으로는 평균 제곱근 오차(Root Mean Square Error, RMSE), 편의(bias), 평균 상대오차(Mean Relative Difference, MRD), 평균 절대 상대오차(Mean Absolute Relative Difference, MARD)를 사용하여 적용 모델의 성능을 비교 분석하였다.

• Nuclear Engineering and Technology
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• v.4 no.1
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• pp.23-30
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• 1972

A study on the preparation of wood-plastic combinations by gamma-ray induced polymerization is carried out. In monomer impregnation, the rates and amounts are determined for various woods. The polymerization rates of various monomers and monomer mixtures impregnated mainly domestic woods are studied varying the total gamma-dose and gamma-dose rates. The obtained data indicate that; 1) in impregnation of monomer, populus deltoides is the fastest in rate, and the most impregnated in amount 2) the general trends of polymerization of monomers ill woods is in the order of vinyl acetate--methyl metacrylate--styrene, ranging from 3 to 15 Mard of total does in rate of 4$\times$10$^4$rad/hr., thus vinyl acetate or methyl metacrylate is suitable monomer in view of polymerization rate, 3) the successful woods in combination with monomer are pinus rigida and pinus densiflora in view of polymerization rate, 4) the monomers in woods are more easily polymerized under the conditions of moderately lower does rate, 2.1$\times$10$^4$rad/hr.

• Korean Journal of Optics and Photonics
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• v.12 no.2
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• pp.143-149
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• 2001

We performed the intracavity frequency-doubling of a tunable continuous-wave Ti:sapphire laser using a lithium triborate $(LiB_3O_5, LBO)$ crystal. For an efficient intracavity frequency-doubling, we measured the spectral and the angular bandwidth about the $\theta$-direction of LBO crystal. The measured values at a fundamental wavelength of 800 nm were 1.54 nm.cm and 3.8 mrad.cm, respectively. As a result of an intracavity frequency-doubling, we obtained the second-harmonic generation output power of 5.3 mW at 400 nm with the full width at half maximum(FWHM) of 0.089 nm from the fundamental output power of 185 mW at 800 nm. The frequency-doubled output was tuned from 397 nm to 403 nm.403 nm.

• Korean Journal of Food Science and Technology
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• v.8 no.3
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• pp.161-171
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• 1976

The meat samples of carp (Cyprinus carpio, Linne) and rainbow trout (Salmo gairdnerii) packaged in aluminum pouches with polyethylene adjuvant were exposed to gamma radiation of doses up to 1.5 Mrad for the purpose of determining optimum dose range required to bring about a significant storage-life extension at refrigerated temperatures. The maximum permissible dose for carp was determined to be 1.5 Mrad and that for rainbow trout 0.2 Mrad, while the optimum dose was 0.25 Mard and 0.05 Mrad, respectively. By irradiating them at each optimum dose, the practical storage-life of carp could be extended from one week to five at both $0^{\circ}\;and\;5^{\circ}C$ and that of rainbow trout from one week to 3-4 weeks at $0^{\circ}C$ and from 3 days to 14 days at $5^{\circ}C$. The carp meat suffered from extensive drip loss during the post-irradiation storage and it could be reduced effectively by dipping the samples into 10% polyphosphate solution prior to the radurization treatment. The rainbow trout was highly radiosensitive, while carp appeard to one of promising species to be radurization treated for the purpose of extending storage-life at refrigerated temperatures.