• 한국멀티미디어학회논문지
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• 제19권5호
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• pp.837-847
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• 2016

Tone mapping for High Dynamic Range(HDR) image provides matching human visual perception between real world scene and displayable devices. Recently, a tone mapping algorithm based on localized gamma correction is proposed. This algorithm is using human visual properties of contrast and colorfulness with background intensity, generating a weight map for gamma correction. However, this method have limitations of controlling enhancement region as well as generating halo artifacts caused by the weight map construction. To overcome aforementioned limitations, proposed algorithm in this paper modifies previous weight map, considering base layer intensity of input luminance channel. By determining enhancement region locally and globally based on base layer intensity, gamma values are corrected accordingly. Therefore, proposed algorithm selectively enhances local brightness and controls strength of edges. Subjective evaluation using z-score shows that our proposed algorithm outperforms the conventional methods.

• Journal of Advanced Marine Engineering and Technology
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• 제27권6호
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• pp.704-713
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• 2003

The effect of partial substitution of tungsten for molybdenum on the microstructure and corrosion resistance in 22Cr-5Ni-3Mo duplex stainless steel(DSS) aging heat treated in a temperature range of 600~$1000^{\circ}C$ has been investigated. Electrochemical tests were carried out for the evaluation of corrosion resistance. Aging treatment had hardly influenced the general corrosion resistance. With the increase of aging time, the pitting corrosion resistance of the DSS had decreased, After aging for 2min at 700~$900^{\circ}C$, the pitting potential of the 3Mo steel decreased remarkably, while that of the W-substituted steel hardly changed. During aging. the intermetallic $\sigma$ and secondary austenite ($\gamma_2$) phases were precipitated. and the pitting corrosion and intergranular corrosion resistance were significantly decreased after aging at 700~$750^{\circ}C$ for 10 h, which could be caused by the $\gamma_2$ formation. The ${\gamma}$$_2$ phase could affect the depletion of molybdenum and chromium in the $\gamma_2/\alpha and \gamma_2/\sigma$ boundaries.

• 한국식품영양과학회지
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• 제30권3호
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• pp.500-504
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• 2001

Gamma irradiation was applied to reduce egg allergy. Ovalbumin (OVA), an egg white protein, was used as model allergen and was gamma-irradiated at 3, 5, or 10 kGy in an aqueous state (2.0 mg/mL). The changes in allergenic and antigenic properties of OVA resulted from gamma irradiation were monitored by ELISA with serum from egg-hypersensitive patients (H-IgE), and mouse monoclonal IgG (M-IgG) or rabbit polyclonal IgG (R-IgG). The binding ability of H-IgE to irradiated OVA was dose-dependently reduced. However, IgGs from animal did better recognize 3 or 5 kGy-irradiated OVA. In the evaluation of immune reactivity using blind test, the reactivity of H-IgE rapidly decreased depending upon the irradiation dose. However, the reactivities of M-IgG and R-IgG was higher at 5 and 3 kGy-irradiated OVA than non-irradiated control. The results provide a new possibility to use irradiation process for reducing the allergenicity of egg white.

• Environmental Analysis Health and Toxicology
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• 제20권3호
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• pp.243-248
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• 2005

Mancozeb (MCZ), a polymeric complex of zinr and manganese salts of ethylene bisthiocarbamate, is widely used in agriculture as fungicidel, insecticides, and herbicides. MCZ can be occupationally and environmentally exposed to human and has been reported to have detrimental effects on the reproductive system, but the toxicity of MCZ on immune responses has not been systematically investigated. We investigated the effects of MCZ exposure on the activities of murine splenocytes through evaluation of splenocytes cellularity and INF-$\gamma$ synthesis. Splenocytes were examned ex vivo from mice orally treated with various doEes of MCZ for 1 day (acute exposure, 2,100, 5,000, 10,000 mg/kg) or ior 5 consecutive days per week for 4 weeks (subacute exposure,250, 1,000, 1,500 mg/kg/day) fellowed by culture for 2 days in the presence of Con A or PHA plus IL-2. Splenocytes Iron naive mice were cultured with various concentration of MCZ (50, 500, 1,000 ng/ml) in the presence of Con A or PHA plus IL-2 for 2 days in vitro. IFN-$\gamma$ production was decreased with the in vitro exposure to all concentration of MCZ. The spleen cellularity and IFN -$\gamma$ production by splenocytes from MCZ -acutely and - subacutely exposured mice were decreased in comparision with that oi control group.

• 방사선산업학회지
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• 제6권3호
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• pp.205-209
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• 2012

The decomposition of 50 pesticides present in an aqueous solution using ${\gamma}-irradiation$ from a $^{60}Co$ gamma-ray source was investigated using laboratory-scale experiment. The rates of decomposition were determined using a gas chromatography-electron capture detector (GC-ECD), high-performance liquid chromatography-photo diode array detector (HPLC-PDA), and HPLC-fluorescence detector (FLD). When the initial concentration of pesticides was 10 ppm, and the radiation dose was 2, 5, 10, 20, and 30 kGy, respectively, 14 pesticide samples showed high removal rates (>50%) at absorbed doses of more than 10 kGy. With the exception of procymidone, they were all completely removed at a 30 kGy irradiation dose. These results provide fundamental data on the reactivity between gamma-irradiation and pesticides in an aqueous solution. Further, an evaluation of the toxicity of radiolytic intermediate products is required.

• Journal of Radiation Protection and Research
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• 제49권2호
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• pp.85-90
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• 2024

Background: This study focuses on the fabrication and characterization of quasi-hemispherical Cd_0.9Zn_0.1Te (CZT) detector for gamma-ray spectroscopy applications, aiming to contribute to advancements in radiation measurement and research. Materials and Methods: A CZT ingot was grown using the vertical Bridgman technique, followed by proper fabrication processes including wafering, polishing, chemical etching, electrode deposition, and passivation. Response properties were evaluated under various external bias voltages using gamma-ray sources such as Co-57, Ba-133, and Cs-137. Results and Discussion: The fabricated quasi-hemispherical CZT detector demonstrated sufficient response properties across a wide range of gamma-ray energies, with sufficient energy resolution and peak distinguishability. Higher external bias voltages led to improved performance in terms of energy resolution and peak shape. However, further improvements in defect properties are necessary to enhance detector performance under low bias conditions. Conclusion: This study underscores the efficacy of quasi-hemispherical CZT detector for gamma-ray spectroscopy, providing valuable insights for enhancing their capabilities in radiation research field.

• 대한방사선방어학회:학술대회논문집
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• 대한방사선방어학회 2011년도 추계 학술발표회 및 심포지엄
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• pp.202-203
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• 2011

• 핵의학기술
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• 제19권2호
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• pp.108-111
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• 2015

Purpose Lately, in accordance with the increasing interest about Healthcare accreditation program and International laboratory accreditation scheme, requirements about the instrument quality management are gradually taking shape. In nuclear medicine In vitro laboratory, the most typical instruments are multi detector gamma counter and automatic dispensing system. Each laboratory continue with the quality control adequate for circumstances. The purpose of this study is to application and establish the new Calibrator[I-125]Set which is efficient at standardization of equipment quality management. Materials and Methods Deviation between detectors were measured with 12 solid samples of the Calibrator[I-125]Set. their activities differ from each other by less than 1%. Multi detector gamma counters are GAMMA-10;Shinjin medics. Inc, Goyansi, Korea(Gamma counter A), SR300;Stratec biomedical systems AG, Gewerbestr, Germany(Gamma counter B) and COBRA II; Packard Instrument Co. Inc, Meriden, USA(Gamma counter C). Evaluation of two automatic dispensing system used A, B liquid tracer of the Calibrator[I-125]Set. After dispensing and counting, calculated using the ratio of the measured value and proposed value. We used solution A for 20, 25ul and solution B for 50, 100ul. Method of data analysis and reference range was provided by kit documentation. Furthermore, we could calculate our counter efficiency indirectly. Results The CV(%) of measured values by Gamma counter A, B, C are 0.34, 0.70, 1.30. Calculated value are 1.05314, 2.10419, 4.08485. Provided reference range is less than 3. A dispensing system's calculated values are 0.986, 0.989, 1.023, 1.017 and B are 0.874, 0.725, 1.021, 0.904. Provided reference range is from 0.95 to 1.05. Also, counter's efficiency are 74.18, 72.79, 74.32% at counter A, B, C and efficiency of the one detector counter is 79.26%. Conclusion If using this Calibrator[I-125]Set after verifying whether quality assurance, is applicable to equipment quality management on behalf of the role of gold standard.

• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.378-383
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• 2016

Background: Radiation dose rates in PRIDE facility is evaluated quantitatively for assessing radiation safety of workers because of large amounts of depleted uranium being handled in PRIDE facility. Even if direct radiation from depleted uranium is very low and will not expose a worker to significant amounts of external radiation. Materials and Methods: ORIGEN-ARP code was used for calculating the neutron and gamma source term being generated from depleted uranium (DU), and the MCNP5 code was used for calculating the neutron and gamma fluxes and dose rates. Results and Discussion: The neutron and gamma fluxes and dose rates due to DU on spherical surface of 30 cm radius were calculated with the variation of DU mass and density. In this calculation, an imaginary case in which DU density is zero was added to check the self-shielding effect of DU. In this case, the DU sphere was modeled as a point. In case of DU mixed with molten salt of 50-250 g, the neutron and gamma fluxes were calculated respectively. It was found that the molten salt contents in DU had little effect on the neutron and the gamma fluxes. The neutron and the gamma fluxes, under the respective conditions of 1 and 5 kg mass of DU, and 5 and $19.1g{\cdot}cm^{-3}$ density of DU, were calculated with the molten salt (LiCl+KCl) of 50 g fixed, and compared with the source term. As the results, similar tendency was found in neutron and gamma fluxes with the variation of DU mass and density when compared with source spectra, except their magnitudes. Conclusion: In the case of the DU mass over 5 kg, the dose rate was shown to be higher than the environmental dose rate. From these results, it is concluded that if a worker would do an experiment with DU having over 5 kg of mass, the worker should be careful in order not to be exposed to the radiation.

• Toxicological Research
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• 제18권1호
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• pp.87-98
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• 2002

This study was conducted to evaluate the safety of a recombinant human Factor VIII(GC-$\gamma$ AHF) manufactured by Korea Green Cross Company with different technology according to the Regulation of Korean Food and Drug Administration (l 998. 12. 3). In acute toxicity test, both genders of Sprague-Dawley rats and Beagle dogs were administered intravenously with GC-$\gamma$ AHF of three doses (3,125, 625 and 125 IU/kg), and single dose of 3,125 IU/kg, respectively. No dead animal and abnormal autopsy findings were found in Control and GC-$\gamma$ AHF treated group. Therefore, the 50% lethal dose ($LD_{50}$) of GC-$\gamma$ AHF was conidered to be higher than 3,125 IU/kg in rats and dogs. In the four weeks repeated intravenous toxicity study, GC-$\gamma$ AHF was administrated intravenosly to both genders of rats and dogs with 3 doses (500, 150, 50 IU/kg). There were neither dead animals nor significant changes of body weights during the experimental Period. In addition, no significant GC-$\gamma$ AHF related changes were found in clinical sign, urinalysis and other finding. Statistically changes were observed in hematological, biochemical and organ weight parameters of treated groups: however these changes were not dose dependent. No histopathological lesion were observed in both control and treated animals. Above data suggest that no observed adverse effect level of test materials in rats and dogs might be over 500 IU/kg/day in this study. In ocular irritation test, any injury on iris, conjunctiva and cornea in rabbits were not observed. The acute ocular irritation index (A.O.I.), mean ocular irritation index (M.O.I.) and Day-7 individual ocular irritation Index (I.O.I.) of GC-$\gamma$ AHF were 0. In the primary skin Irritation test, the primary irritation index (P.I.I.) oj GC-$\gamma$ AHF were 0. Therefore, the GC-$\gamma$ AHF is considered not to have the primary skin and eye toxicity in rabbits. In active systemic anaphylaxis (ASA) test, GC-$\gamma$ AHF and GC-$\gamma$ AHF emulsified with Freund's complete adjuvant (FCA) did not induce any symptom of anaphylactic shock in guinea pigs. In passive cutaneous anaphylxis (PCA) test, after sensitization with antisera of GC-$\gamma$ AHF sensitized mice, blue spots were observed on the hypodermis of back of rats, but diameter of each spot was smaller than 5 mm in each test groups except the positive control group. Based on the results of this study, GC-$\gamma$ AHF is not conidered to have any antigenic potential. In conclusion, at levels of up to 500 IU/kg, GC-$\gamma$ AHF did not produce treatment-related toxicity under the conditions of these acute-, four week repeated-toxicity, primary skin and eye toxicity, and antigenicity test.