• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.1028-1033
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• 2013

As safety and security systems of shipping logistics are reinforced all over the world, ubiquitous technology-based core technology for safety and security is developing to build the system of logistics security. It is feared that the logistics security system of Korea has a possibility to technically depend on developed countries in the futures. Because the essential skills and equipment to retain security of logistics are not developed. It is urgent to introduce a logistics security system that fully integrates the entire logistics segment in the future. Thus, the necessity of developing the portable radiation detector which can detect gamma-ray nuclide is increasing for reinforcing safety and security systems. In this paper, a research suggests the implementation of portable radiation detector platform using Cortex-A8.

• Journal of Radiation Protection and Research
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• v.36 no.1
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• pp.16-23
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• 2011

Accurate measurement of uranium enrichment is very important in nuclear material accountability. The analysis uncertainty of the uranium enrichment measurement with gamma-ray analysis was studied in the present work. FRAM (Fixed energy Response function Analysis with Multiple efficiencies) code was used to determine the uranium enrichment. If the shield materials were placed between the detector and the sample, the error was measured and analyzed. Measurement time was varied and the dependency of the analysis uncertainty on the measurement time was studied. Transmitted gamma-ray intensities and FWHMs of the peaks in the energy spectrum were measured as the shield thickness was varied. The transmitted gamma-ray intensity follows shape of the exponential function, and the FWHM was almost independent of the shield thickness. The uncertainty of FRAM analysis was studied when the thick shield material was placed between the detector and the sample. Our work could be helpful in analysis of the fissile material in uranium sample.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.867-876
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• 2005

The microbial contamination of ice cream product commercially available in Korea was determined using ice bar, ice cream, ice milk and non-milk fat ice cream. Irradiation effect on enhancement of microbiological safety was also investigated at doses of 1, 3, and 5 kGy. In all products, yeast and molds were not detected, however, total aerobic and coliform bacteria were detected at 1-2 and 1-1.5 Log CFU/g level, respectively. According to the different flavor used in ice cream, total aerobic bacteria were detected as 2.30, 2.90, and 3.32 Log CFU/g level in vanilla, chocolate, and strawberry ice cream, respectively. Yeast and mold was not detected in vanilla ice cream but 2.30 and 2.70 Log CFU/g in chocolate and strawberry ice cream, respectively. Coliforms were also detected 1-2 Log CFU/g in the ice cream with different flavors. Listeria inocua and Escherichia coli were detected from 3 commercial samples but Salmonella spp. was not detected using API kit. Gamma irradiation significantly reduced the level of the contaminated total aerobic bacteria, yeast and molds and coliform population in the ice creams. These results indicated that irradiation(5kGy or less) is effective to ensure safety of ice cream.

• Journal of the East Asian Society of Dietary Life
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• v.8 no.4
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• pp.430-440
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• 1998

Meat is a perishable product since it offers favorable conditions for microbial contamination and multiplication. Besides, undercooked and raw meat has been linked to outbreaks of hemorrhagic diarrhea due to the presence of microbial pathogens. Therefore, this study was conducted to find out the effect of the use of gamma-irradiation in order to improve preservation and eliminate this microorganisms. The Initial level of microbial contamination in pork was 1.1$\times$10$^3$ CFU/g (aerobic bacteria), 5.3$\times$10$^3$CFU/g (psychrophile), 3.1$\times$10$^3$ CFU/g (coliforms) and 3.2$\times$10$^3$ CFU/g(Listeria), All kinds of contaminated microorgnisms were sterilized by gamma irradiation at 3 kGy. The proximate composition of pork was not significantly changed by irradiation dose and storage period. The pH was slightly increased during storage period and titratable acidity decreased. However, no significant changes in pH and acidity were observed by gamma irradiation. There was no difference in total amino acid content regardless of irradiation dose and storage period. Glutamic acid was detected at high levels throughout the storage period. The major mineral compositions of pork were potassium, phosphorus, sodium, magnesium. No significant difference in the components of minerals were observed by gamma irradiation.

• Journal of the East Asian Society of Dietary Life
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• v.8 no.4
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• pp.412-421
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• 1998

Physicochemical and microbiological properties of red beans, soybeans, barleys, and corns irradiated by gamma-ray at 1.2 kGy, 10.1 kGy, or 30.5 kGy were investigated. Moisture content and crude lipid content of the irradiated cereals showed no significant difference from the nonirradiated group. TBA values of corns irradiated at 30.5 kGy increased. Gamma irradiation reduced the numbers of mesophilic and psychrotrophic bacteria in the cereals. Yeasts and molds were reduced below detection levels even at 1.2 kGy dose-irradiation. There was no significant difference in reducing sugars between the irradiated cereals and the nonirradiated ones except corns. Stachyose, raffinose, and sucrose of soy beans and sucrose of barleys increased by 30.5 kGy dose-irradiation. Loss of riboflavin content of the irradiated samples was not observed except red beans irradiated at 30.5 kGy. In Hunter's color, b value of the red bean powder increased but L value of the soybean powder decreased by the Irradiation. L, a, and b values of the barley powder slightly increased under 30.5 kGy dose-irradiation and b value of the corn powder decreased under 10.1 or 30.5 kGy-dose irradiation.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.3
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• pp.275-284
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• 2006

In the measurement of gamma rays emitted from the nuclide in the radioactive waste drum, to analyze the nuclide concentration accurately, it is necessary to use the proper calibration standards and to correct for the attenuation of the gamma rays. Two drums having a different density were used to analyze the nuclide concentration inside the drum in this study. After carrying out the system calibration, we measured the gamma rays emitted from the standard source inside the model drum with changing the distance between the drum and the detector. The measured values were corrected with the three kinds of gamma attenuation correction methode, as a results, the error was less than 10 % in the low density drum and less than 25 % in the high density drum. The measured activity in the short distance was more accruable than in the long distance. The transmission correction for the mass attenuation showed good results(very Low error) compared to the mean density and the differential peak correction method.

• Journal of Animal Science and Technology
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• v.49 no.4
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• pp.515-522
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• 2007

To develop the manufacturing method of ice cream with microbiologically safe and proper sensory quality using irradiation for sensitive consumer, 3 different flavors, which were resistant to their flavors against irradiation, were selected and used for ice cream manufacturing to reduce the irradiation-induced off-flavor problem. The general composition was not different among treatments. Total aerobic bacteria were detected as 2.38, 1.23, 1.38, and 1.15 log CFU/g level in ice cream with control(no flavor added), spearmint, mint, and citrus flavor, respectively. No viable cells were observed by irradiation at 1 kGy except for the control. Sensory evaluation indicated that the irradiated ice cream with spearmint flavor at 1 kGy and citrus flavor at 3 kGy had higher overall acceptability. Therefore, a low dose irradiation (less than 3 kGy) with mint or citrus flavors may enhance the safety of ice cream with proper sensory quality for sensitive consumer.

• Analytical Science and Technology
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• v.16 no.1
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• pp.12-24
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• 2003

For the design and set-up of neutron induced prompt ${\gamma}$-ray spectroscopy system using $^{252}Cf$ neutron source, the effects of shielding and moderator materials have been examined. The $^{252}Cf$ source being used for TLD badge calibration in Korea Atomic Energy Research Institute was utilized for this preliminary experiment. The ${\gamma}$-ray background and prompt ${\gamma}$-ray spectrum of the sample containing Cl were measured using HPGe (GMX 60% relative efficiency) located at the inside of the system connected to notebook PC at the outside of the system (about 20 meter distance). The background activities of neutron and ${\gamma}$-rays were measured with neutron survey meter as well as ${\gamma}$-ray survey meters, respectively and the system was designed to minimize the activities. Prompt ${\gamma}$-ray spectrum was measured using ${\gamma}$-${\gamma}$ coincident system for reduce the background and the continuum spectrum. The optimum system was designed and set up using the experimental data obtained.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.1100-1102
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• 2015

In the study, stereo-based of gamma-ray sources detector for the space including the gamma-ray source to scan in a raster scan method, and obtains a visible light image and the gamma-ray image. We went to retrieve and visualize the distance to source and the direction of the 3-dimension information from Stereo gamma-ray detectors. Configuration of the detector consisted of gamma-ray detecting sensor for gamma-ray Sources, pan-tilt for the scanning of the raster for detecting sources, and CCD camera for visible-light image. Implement a stereo structure of the device to measure the spatial distribution of source, the gamma-ray Detector and CCD camera for the stereo image acquisition was as each configuration 2. The gamma-ray detector and a visible light camera to revision the distribution of detection source, After performing each of the cameras of the stereo correction and shows the distribution of the gamma-ray Sources through 중첩 visible light image and the gamma-ray image. After Rectification process of Left and right image, we were derived visualization results of the stereo image.

• Journal of Radiation Protection and Research
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• v.39 no.2
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• pp.81-88
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• 2014

Recently, a new imaging method, gamma vertex imaging (GVI), was proposed for the verification of in-vivo proton dose distribution. In GVI, the vertices of prompt gammas generated by proton induced nuclear interaction were determined by tracking the Compton-recoiled electrons. The GVI system is composed of a beryllium electron converter for converting gamma to electron, two double-sided silicon strip detectors (DSSDs) for the electron tracking, and a scintillation detector for the energy determination of the electron. In the present study, the modules of a charge sensitive preamplifier (CSP) and a shaping amplifier for the analog signal processing of DSSD were developed and the performances were evaluated by comparing the energy resolutions with those of the commercial products. Based on the results, it was confirmed that the energy resolution of the developed CSP module was a little lower than that of the CR-113 (Cremat, Inc., MA), and the resolution of the shaping amplifier was similar to that of the CR-200 (Cremat, Inc., MA). The value of $V_{rms}$ representing the magnitude of noise of the developed system was estimated as 6.48 keV and it was confirmed that the trajectory of the electron can be measured by the developed system considering the minimum energy deposition ( > ~51 keV) of Compton-recoiled electron in 145-${\mu}m$-thick DSSD.