• Journal of Advanced Navigation Technology
• /
• v.20 no.6
• /
• pp.612-616
• /
• 2016

Gamma-ray must be detected and processed immedietely after generation of it in the circumstances where it exists. Software methology may be used to process randomly generated signals, but its memory size and processing time become large. By the way, the hardware circuit to detect randomly generated signals is generalized in industrial site, while those circuits are not able to answer to the cases whose amplitude are very small and also speed high. We researched and developed hardware based peak-hold circuit that is able to detect peaks of gamma-ray signals through direct reading out their values by ADC at the time of maximum reaching for the small amplitude and high speed signals, and proposed and estimated its results in this paper. This peak-hold circuit is adequate to use in the radiation circumstances in which the gamma-rays are heavy because its circuit can catch high speed signals efficiently without software signal processing supports.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.944-945
• /
• 2016

Gamma-ray Detector for gamma-ray imaging device is composed of a shielding body for shielding gamma-rays incident from the radiation source. Distribution of the gamma ray can be represented by the distribution information on the direction in which the detecting section and the signal through the incident hole of collimator. The role of the shield is important because all signals should be treated as noise except for the signal from the incident hole.In this paper In this paper, we have produced a compact, lightweight and Collimator shield by changing the structure and physical properties with respect to the collimator and shielding of lead-based gamma-ray detectors. And we analyzed the shielding effectiveness relative to the incident gamma ray sphere measured signal value through the gamma irradiation test facility. The results confirmed that the production and Collimator shielding the imaging device Implementing more efficient to implement.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.185.2-186
• /
• 2003

세계적으로 최소가공식품(minimally processed foods)의 시장이 확대되면서, 최소가공된 과채류의 미생물학적 안전성 확보가 중요한 사안으로 대두되고 있다. 이에 본 연구는 김치제조용 원료배추를 모델로 하여 감마선 및 가스치환 포장법을 병용한 절임배추의 미생물학적, 이화학적 특성을 평가하였다. Fresh-cut상태의 절임배추(염농도 3%)를 각각 air, 100% $CO_2$, 25% $CO_2$/75% $N_2$가스를 주입하여 포장한 후 0, 0.5, 1, 2 kGy의 선량으로 감마선 조사하여 3주 동안 저장하면서 분석에 사용하였다. Total aerobic bacteria, coliforms, Salmonella, lactic acid bacteria의 분포를 살펴본 결과, $CO_2$혹은 $CO_2$/$N_2$포장과 감마선을 병용처리한 경우 저장기간 동안 total aerobic bacteria, coliforms 및 Salmonella 모두 1kGy의 선량에서 90% 이상 감소시킬 수 있는 것으로 나타나, 일반 함기포장보다 효과적인 것으로 나타났다. 색도 및 물성은 포장방법에 따른 차이를 보이지 않았으며, pH의 경우도 감마선 조사 및 가스치환 포장시 더욱 효과적으로 유지할 수 있었다. FRAP(ferric reducing antioxidant power) value 및 DPPH radical 소거능과 같은 생리활성 능력을 측정한 결과 포장방법 및 감마선 조사에 의한 차이를 보이지 않았다. 따라서 가스치환 포장 및 감마선 조사를 병용시 함기포장구 보다 낮은 감마선 조사선 량에서 병원성 미생물을 제어할 수 있었으며, 이화학적 품질이 우수하고 저장성이 향상된 절임배추를 제조할 수 있었다.7로 4$0^{\circ}C$ 진공건조와 -7$0^{\circ}C$ 동결건조의 L값 변화보다 큰 변화를 보였고, 또한‘a’값과 ‘b’값의 경우도 마찬가지로 5$0^{\circ}C$ 열풍건조의 경우가 양파의 내부와 외부면의 적색도 및 황색도 변화가 크게 일어나는 경향을 나타내었다. 건조과정 중 vitamin C의 함량변화는 건조에 의한 수분함량의 감소로 vitamin C의 함량은 상대적으로 증가하였고, -7$0^{\circ}C$ 동결건조의 경우가 가장 높은 vitamin C의 증가량을 나타내었고, 그와 반대로 5$0^{\circ}C$ 열풍건조의 경우는 열에 의한 vitamin C의 변화로 인한 상대적 증가량은 감소하는 경향을 나타내었다.아현미가 더욱 조밀하였다. 10시간 탈삽처리에서 상품성이 우수하였다. 그러나 25'E 28시간 탈삽처리는 탈삽의 균일도가 다른 처리에 비해 떨어지는 경향이었다. 경우, 사과표피의 색도 변화를 현저히 지연시킴을 확인하였다. 또한 control과 비교하여 성공적으로 사과에 코팅하였으며, 상온에서 보관하여을 때 사과의 품질을 30일 이상 연장하는 효과를 관찰하였다. 이들 결과로부터 대두단백질 필름이 과일 등의 포장제로서 이용할 가능성을 확인하였다.로 [-wh] 겹의문사는 복수 의미를 지닐 수 없 다. 그러면 단수 의미는 어떻게 생성되는가\ulcorner 본 논문에서는 표면적 형태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요 소를 지닌 병렬적 합성어([$[W1]_{XO-}$ $[W

• Journal of Radiation Protection and Research
• /
• v.34 no.4
• /
• pp.190-194
• /
• 2009

Gamma spectral results for macroalgae samples taken from the environment of Ulchin nuclear power plants in Korea (east coast), showed 766 keV peaks, which were identified as $^{95}Nb$ by several research institutes. After the enhancement of liquid radioactive waste disposal facility at Ulchin NPP site, the $^{95}Nb$ amount in the liquid radioactive waste outflow has drastically reduced, but the expected reduction in $^{95}Nb$ specific activity from environmental samples did not actually show up on gamma spectroscopy. Detailed re-investigation revealed that along with 766 keV peak, other peaks (63, 92 and 1001 keV) from $^{234}Th-^{234}mPa$ decay series were also detected on spectroscopy, and that the measured half lives of the four peaks were very close to known half life of $^{234}Th-^{234}mPa$ decay series, which is 24.1 day. The measured gamma yield ratios of 766 keV peak to 1001 peak were very close to known ratio 0.35 for $^{234}mPa$. It is concluded that 766 keV peaks on gamma spectroscopy of Ulchin NPP environmental samples were mainly from $^{234}mPa$, which is one of naturally occurring radionuclides.

• Food Science and Preservation
• /
• v.12 no.1
• /
• pp.28-35
• /
• 2005

The storage temperature significantly affected the microbiological quality of the chicken breast In the non-inadiated samples at $30^{\circ}C$, aerobic plate count (APC) and Echerichia coli count of the samples considerably increased during 3 days of storage and were eliminated by an irradiation at dose of 10 kGy or more. The APC and E coli count of the samples stored at $5^{\circ}C$ were reduced to below the limit of detection (< 2 log CFU/g) through the whole storage period by an irradiation at 5 kGy or mote. There was no significant difference in the TBA values between the non-inadiated and inadiated samples, which were not significantly higher in the irradiated samples than the non-inadiated samples during 2 weeks of storage at $5^{\circ}C$. According to the same-different test and acceptance test the sensory quality of the irradiated chicken breast was not significantly different from that of the non-inadiated sample even at 10 kGy. It is found that gamma irradiation is an effective tool to improve the quality of chicken breast in a group-meal service. It was also found that there was no evidence that an irradiation induced mutagenicity in the chicken breast meat.

• Food Science and Preservation
• /
• v.11 no.4
• /
• pp.431-436
• /
• 2004

Associated with microbial decontamination and quarantine treatment of dried red pepper, the samples was gamma-irradiated (5, 10 kGy) and fumigated (methyl bromide/MeBr, phosphine/$PH_3$) to compare their Hunter's color (L, a, b, ${\Delta}E$) and sensory properties by types (whole, powder, pericarp, seed) during storage under room conditions($18{\pm}12^{\circ}C$). Whole pepper maintained higher lightness (L value) than other groups, while powdered pepper showed higher redness (a value) during storage. Immediately after treatments there was little difference in the overall color difference (${\Delta}E$) among the groups. After 8 months, a higher redness was observed in $PH_3$ group of whole pepper and 5 kGy group of powdered pepper, respectively(p<0.05). Redness of irradiated pericarps was apparently reduced following 8 months of storage and a similar pattern was found in fumigated samples. The yellowness (b value) of pepper seed was lowest in 10 kGy sample (p<0.05), but insignificant difference was observed among treatment groups with storage time. Sensory properties of whole and powdered peppery were little changed by both treatments under commercial conditions. Sensory scores of irradiated or fumigated samples were higher than that of non-treated control with storage time, which was more significant in the powdered than in the whole samples.

• Food Science and Preservation
• /
• v.20 no.1
• /
• pp.97-103
• /
• 2013

The effects of gamma irradiation at medium dose levels on commercial starches (corn starch/CS, sweet potato starch/SS, and potato starch/PS) were investigated in terms of its color and lipid oxidation. The CS, SS, and PS samples were irradiated at 0, 1.5, 3, 4.5 and 6 kGy by a Co-60 gamma irradiator and used for measuring Hunter's colors and TBA value. Irradiation doses applied did not cause apparent changes in Hunter color parameters between the control and irradiated groups. But, the decrease in lightness (L value) for CS and the increase in both redness (a value) for SS and yellowness (b value) for PS were observed, respectively, thereby resulting in slight increase in overall color difference (${\Delta}E$) upon irradiation. Browning intensity observed with the naked eye for gelatinized starches by irradiation doses was also gradually increased along with irradiation dose, which was more remarkable in SS. The thiobarbituric acid (TBA) values of samples showed a dose-dependant increase with ${\geq}0.9964$ of $R^2$ (p<0.05).

• The Journal of Korean Society for Radiation Therapy
• /
• v.23 no.2
• /
• pp.97-102
• /
• 2011

Purpose: IMRT QA using 2Dimensional array detector is carried out with condition for discrete dose distribution clinically. And it can affect uncertainty of evaluation using gamma method. We analyze gamma index variation according to grid size and suggest validate range of grid size for IMRT QA in Hospital. Materials and Methods: We performed QA using OniPro I'mRT system software version 1.7b on 10 patients (head and neck) for IMRT. The reference dose plane (grid size, 0.1 cm; location, [0, 0, 0]) from RTP was compared with the dose plane that has different grid size (0.1 cm, 0.5 cm, 1.0 cm, 2.0 cm, 4.0 cm) and different location (along Y-axis 0 cm, 0.2 cm, 0.5 cm, 1.0 cm). The gamma index variation was evaluated by observing the level of changes in Gamma pass rate, Average signal, Standard deviation for each case. Results: The average signal for each grid size showed difference levels of 0%, -0.19%, -0.04%, -0.46%, -8.32% and the standard deviation for each grid size showed difference levels of 0%, -0.30%, 1.24%, -0.70%, -7.99%. The gamma pass rate for each grid size showed difference levels of 0%, 0.27%, -1.43%, 5.32%, 5.60%. The gamma evaluation results according to distance in grid size range of 0.1 cm to 1.0 cm showed good agreement with reference condition (grid size 0.1 cm) within 1.5% and over 5% in case of the grid size was greater than 2.0 cm. Conclusion: We recognize that the grid size of gamma evaluation can make errors of IMRT QA. So we have to consider uncertainty of gamma evaluation according to the grid size and apply smaller than 2 cm grid size to reduce error and increase accuracy clinically.

• Food Science and Preservation
• /
• v.8 no.3
• /
• pp.291-295
• /
• 2001

Photostimulated luminescence (PSL) analysis was applied to determine whether some agricultural commodities of Korean and Chinese origins have been irradiated or not. Cereals (brown rice and buckwheat) and legumes (soybean, peanut, fed bean and mung bean) were exposed to gamma irradiation at 0.5 ∼4 kGy The Korean garlic was irradiated at 0.05 ∼0.5 kGy. Cereals and mung bean were tool applicable to the PSL measurement, showing the intermediate values between the lower (700 photon counts, negative) and the upper threshold values (5,000, positive), however PSL values determined for soybean, peanut, red bean and garlic were suitable for being discriminated between nonirradiated and irradiated samples. There was no significant difference in PSL properties accgrding to the sample origins.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.2
• /
• pp.133-142
• /
• 2014

According to the development of medical information systems, shortened examination time per patient could increase the number of treatments, resulting in the rapid growth of the amount of medical data. Studies on how to efficiently compress and store medical text data of increasing patients are in progress. However, previous methods have the shortcoming of compressing medical text data as it is, resulting in low compression rate. This research tries to overcome the problem by using the gamma coding method which enables compression in bit unit. We propose a new compression scheme which encodes the deviations between measured values and normal range values. Furthermore, we suggest to use the previous value with the least deviation from the measurement as the standard value to encode that deviation. Even though the suggested methods are simple, they have high compression rates. Through performance evaluation, we show that the suggested methods are more efficient than the previous methods.