• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2000.11a
• /
• pp.419-427
• /
• 2000

The 4 by 4 microstrip phased array antenna designed and radiation characteristics are studied. The design frequency was chosen to be 5.8GHz. Chebyshev ratio was achieved by unequal power divider and Wilkinson power divider. The ratio of current at each port is 1 : 2.6 : 2.6 : 1 and then side lobe level is less than -30 dB. It is shown that the radiation beam direction can be changed up to 30。 by control the phase at each port. The result can be used to design electrically controllable microwave scanning antennas.

• Journal of the Korean Academy of Clinical Electrophysiology
• /
• v.10 no.2
• /
• pp.1-6
• /
• 2012

Purpose : This study is to investigate the modulatory effects to the ultraviolet induced erythema of pain processing system. Methods : Thirty six healthy volunteers were divided into none treatment group (n=6), indomethacine group (n=6), subsensory level electrical stimulation group (n=6), sensory level electrical stimulation group (n=6), motor level electrical stimulation group (n=6), noxious level electrical stimulation group (n=6). Subjects were induced erythema for three times minimal erythema dose (MED) at upper arm of dermatome C6 level. Each experimental group had mechanical pain threshold (MPT), electrical pain threshold (EPT), thermal pain threshold (TPT). Results : This study revealed that we observed that pain thresholds were significantly correlated with each other in pain processing system. The effect of electrical stimulation levels evaluates were shown to be significant differences pain control effect in electrical stimulation group (sensory, motor level electrical stimulation groups) more than indomethacine group, subsensory level and control group. Conclusion : In this study, it was found that the effect of ultraviolet induced erythema of pain control by modulatory electrical stimulation.

• Journal of Veterinary Clinics
• /
• v.14 no.2
• /
• pp.208-214
• /
• 1997

The objective of this study was (a) to examine the change of bloodchemistry and (b) to investigate the secretion trend of endocrinological substance in a dog model after laser-beam radiation at different level of frequency (250 Hz, 2,000 Hz, 5,000 Hz and 8,000 Hz). The experimental groups were divided into four groups were divided into four groups on the basis of the level of frequency radiated and stimulated for five minutes. Before stimulation and after a lapse of time (10-minute, 30-minute and 60-minute) all dogs were checked the following parameters; cortisol, ACTH, RBC, hemoglobin, hematocrit, WBC, Ca, P, ALT, AST and creatinine. The results were as follow: ten minutes after stimulation, cortisol level of 250 Hz group, 2,000 Hz group, 5,000 Hz group and 8,000 Hz group was increased 18.8%, 20.5%, 23.2% and 309%, respectively. Ten minutes after stimulation, ACTH level of 250 Hz group, 2,000 Hz group, 5,000 Hz group and 8,000 Hz group was increased 26.7%, 26.6%, 30.5% and 29.5%, respectively. It began to decrease and at 30-minute after stimulation resturned to pre-stimulation level at 60-minute after stimulation. In blood examination RBC, hemaoglobin, hematocrit and WBC level showed slight increase and decrease and returned to pre-stimulation level at 60-minute after radiation. In bloodchemical examination serum calcium, inorganic phosphorus, ALT, AST and creatinine level were within normal physiological ranges.

• Journal of Radiation Protection and Research
• /
• v.38 no.4
• /
• pp.179-184
• /
• 2013

The biological effects of radiation are dependent on the dose rate and dose of radiation. In this study, effects of dose and dose rate using whole body radiation on plasma cytokines and blood count from male BALB/c mice were evaluated. We examined the blood and cytokine changes in mice exposed to a low (3.49m Gy $h^{-1}$) and high (2.6 Gy $min^{-1}$) dose rate of radiation at a total dose of 0.5 and 2 Gy, respectively. Blood from mice exposed to radiation were evaluated using cytokine assays and complete blood count. Peripheral lymphocytes and neutrophils decreased in a dose dependent manner following high dose rate radiation. The peripheral lymphocytes population remained unchanged following low dose rate radiation; however, the neutrophils population increased after radiation. The sera from these mice exhibited elevated levels of flt3 ligand and granulocyte-colony-stimulating factor (G-CSF), after high/low dose rate radiation. These results suggest that low-dose-rate radiation does not induce blood damage, which was unlike high-dose-rate radiation treatment; low-dose-rate radiation exposure activated the hematopoiesis through the increase of flt3 ligand and G-CSF.

• Journal of radiological science and technology
• /
• v.47 no.2
• /
• pp.79-86
• /
• 2024

This study was to conducted on the general public living in the Busan area to determine their knowledge and awareness of radiation. A questionnaire written in Google Form was distributed, and 193 questionnaires were analyzed. Independent samples t-test and one-way ANOVA were conducted to verify differences in variables according to the characteristics of the study subjects. Correlation analysis was conducted to determine the relationship between variables. Multiple linear regression analysis was conducted to confirm the correlation between variables. As a result of the study, firstly, The knowledge and awareness of radiation and confidence level of radiological information were found to be high among men and unmarried group. Second, as a result of analysis according to occupation, it was found that students had a positive perception of radiation. Third, the Internet and TV are the most commonly used channels for obtaining information about radiation. Lastly, the thing that has the greatest impact on the awareness of radiation is the reliability of the obtained radiation information. In order to relieve excessive anxiety about radiation and to gain a proper understanding of radiation, the reliability of information about radiation is important. Therefore, it is believed that active efforts are needed to provide accurate information about radiation by utilizing media that are widely used by citizens.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2004.06a
• /
• pp.419-424
• /
• 2004

Various radiation counters have been using to determine radioactivity of radwastes for disposal. A radiation counting system was set up using a radiation detector chosen in this study and its stability was investigated through the periodic determination of background and counting efficiencies in accordance with a quality control program to increase the confidence level. The average background level for the $\gamma$-spectrometer was 1.59 cps and the average counting level for the standard sample was 45248 Ops within $2{\sigma}$ confidence levels. The average alpha background level for the low background ${\alpha}{\beta}$ counting system was 0.31 cpm and the efficiency for alpha counting was 34.38%. The average beta background level for the ${\alpha}{\beta}$ counting system was 1,30 cpm and the efficiency for beta counting was 46.5%, The background level in the region of 3H and 14C for the liquid scintillation counting system was 2.52 and 3.31 cpm and the efficiency for alpha counting was 58.5 and 95.6%, respectively. The minimum detectable activity for the$\gamma$-spectrometer was found to be 3.2 Bq/$m\ell$ and 3.8 Bq/$m\ell$ for the liquid scintillation counter, and 20.5 and 23.0 Bq/$m\ell$, respectively for the $\alpha$ and $\beta$ counting system.

• Nuclear Engineering and Technology
• /
• v.53 no.9
• /
• pp.3035-3043
• /
• 2021

Epidemiological research has revealed that radiation exposure can cause cataracts. The Korean nuclear regulatory body has proposed the reduction of the occupational dose limit for the lens of the eye from 150 mSv/y to 100 mSv/5y, with an additional limitation of not exceeding 50 mSv/y for a specific year, taking into account the recommendations of the International Commission on Radiological Protection, and the International Atomic Energy Agency. This means that radiation workers should receive the same level of radiation safety for the lens of the eye as for whole-body protection. Korean nuclear power plants (NPPs) are conducting research to establish the radiation protection program for the lens of the eye. In terms of the preliminary results of the implementation of the radiation protection program for the lens of the eye dedicated to Korean NPPs, this review article summarizes the current state of understanding of the regulations, technical guidance, eye lens dosimeters, and radiation field conditions resulting in lens dose.

• Journal of radiological science and technology
• /
• v.41 no.6
• /
• pp.581-586
• /
• 2018

This study was conducted to analyze factors Influencing Protective Behavior against Radiation Exposure using questionnaires for 231 radiological technologists working in Computed Tomography(CT) examination room with high radiation dose in diagnostic radiology field. Statistical analysis of the collected data revealed that the reasons for partially shielding the examination part in the CT scan were the lack of protective equipment, securing of radiation justification, being annoying and maybe not being harm to adults in order. It was also revealed that the variables influencing the protective behavior were protective behavior against radiation harm, self-efficacy, protective environment, organization culture, protective knowledge and protective instrument in order. The higher the radiological protective environment(${\beta}=0.245$) and the lower the radiological protective knowledge(${\beta}=-0.034$), the more influential the protective behavior against radiation harm was. In this study, it was shown that non examination parts were not shielded in the CT scan. Therefore, it is necessary to improve the level of protective environment, to cultivate knowledge to improve the protective behavior against radiation harm and to have an intervention strategy for concrete action.

• Journal of Radiation Industry
• /
• v.17 no.4
• /
• pp.443-449
• /
• 2023

KAERI(Korea Atomic Energy Research Institute) is conducting research and development of large-scale radiation generators and the latest radiation measuring instruments. In particular, research and development of security screening equipment using an electron beam accelerator and a neutron generator is in progress recently. Globally, 20 ft containers are used to transport imports and exports, and electron beam accelerators are radiation sources to measure the shape of the material inside the container during customs inspections in each country. KAERI is developing a device that can use an electron beam accelerator and a neutron generator sequentially to grasp the shape of various materials as well as the location of the internal target material. In this study, when using the neutron generator, the radiation dose and the degree of activation by neutron for the facility and surrounding environment, facility equipment were simulated using MCNP and FISPACT code. As a result, the shielding structures inside and outside the radiation control area were satisfactory to the reference level established conservatively based on the Korean Nuclear Act.

• Journal of Life Science
• /
• v.15 no.1 s.68
• /
• pp.61-65
• /
• 2005

Using two japonica rice cultivars (Ilpumbyeo and Sanghaehyanghyella), which are distinguishable by the brown planthopper (BHP) resistance maker (R208), a relationship between the BPH resistance gene (Os-Bil) and salt-tolerance was investigated. To do this, changes in the expression level of Os-Bil by the salt stress were quantified by the real-time PCR in the two cultivars, and compared with those in other two indica rice cultivars (Pokkali and IR29). In Ilpumbyeo, the expression level of Os-Bil decreased by the treatments of 50 and 200 mM NaCl in a concentration-dependent manner, and in Sanghaehyanghyella it rather increased slightly at 50 mM but decreased drastically at 200 mM. Comparably, IR29, a salt-sensitive cultivar, showed a reduction of the Os-Bil gene expression after the treatment of 100 mM NaCl, but Pokkali, a salt-tolerance cultivar, rather increased about two times in the level of Os-Bil transcripts. These results suggest that the BPH resistance gene may involve in the difference in the salt-tolerance at least between the two indica rice cultivars.