• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1807-1816
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• 2020

In this work, a Gaussian Process (Kriging) approach is proposed to provide efficient dose mapping for complex radiation fields using limited number of responses. Given a few response measurements (or simulation data points), the proposed approach can help the analyst in completing a map of the radiation dose field with a 95% confidence interval, efficiently. Two case studies are used to validate the proposed approach. The First case study is based on experimental dose measurements to build the dose map in a radiation field induced by a D-D neutron generator. The second, is a simulation case study where the proposed approach is used to mimic Monte Carlo dose predictions in the radiation field using a limited number of MCNP simulations. Given the low computational cost of constructing Gaussian Process (GP) models, results indicate that the GP model can reasonably map the dose in the radiation field given a limited number of data measurements. Both case studies are performed on the nuclear engineering radiation laboratories at the University of Sharjah.

• The Journal of the Korean dental association
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• v.54 no.2
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• pp.155-162
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• 2016

Radiographs can help in the diagnosis and treatment planning, but the exposure to ionizing radiation may elevate the risk of developing cancer in a person's lifetime. The objective of this review is to briefly summarize 1) radiation risk, especially cancer risks associated with diagnostic imaging, 2) linear, non-threshold (LNT) hypothesis, 3) the risks of radiation exposure to a fetus, and 4) the campaign of Image Gently. The individual risk of radiation-related cancer from any single medical imaging procedure is extremely small and it is not likely to be cancer risk at doses lower than 100 mGy, but patients may be harmed by avoiding diagnostic imaging due to fear of radiation hazard. Dentists need to understand the radiation doses delivered by various radiographic techniques and the acceptable exposure thresholds to effectively advise the patient and to reduce the unnecessary radiation

• The Journal of the Korean dental association
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• v.52 no.3
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• pp.147-152
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• 2014

Recently the patient exposure by medical and dental x-ray examination has grown rapidly and diagnostic radiology represents the largest source of man-made radiation. For the patient protection, the principle of justification and optimization should be followed. All the radiographic examinations have to show a potential benefit to the patient weighing against the potential risk. After they are justified, the radiographic exposure should be kept as low as reasonably achievable, taking into account economic and social factors. For the safe use of radiation in dentistry, the radiation safety management in accordance with the legislation is important. The present status and the future of radiation safety management in dental radiology in Korea and other country will be discussed.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.159-162
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• 2009

The necessity of radiation dosimeter with precise measurement of radiation dose is increased and required in the field of spacecraft, radiotheraphy hospital, atomic plant facility, etc. where radiation exists. Until now, a low power commercial metal-oxide semiconductor(MOS) transistor has been tested as a gamma radiation dosimeter. The measurement error between the actual value and the measurement one can occur since the MOSFET(MOS field-effect transistor) dosimeter, which is now being used, has two gates with same width. The measurement value of dosimeter depends on the variation of threshold voltage, which can be affected by the environment such as temperature. In this paper, a radiation dosimeter having a pair of MOSFET is designed in the same silicon substrate, in which each of the MOSFETs is operable in a bias mode and a test mode. It can measure the radiation dose by the difference between the threshold voltages regardless of the variation of temperature.

• Korean Journal of Bronchoesophagology
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• v.4 no.2
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• pp.177-181
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• 1998

Provox is now widely used for voice rehabilitation for total laryngectomized patient because of its low airway resistance and easiness for phonation. This study was designed to reveal the influence of radiation therapy on Proven complications. Forty-four patients who underwent total laryngectomy were grouped into group A (no radiation), group B(radiation and then Provox insertion), group C(Proven insertion and then radiation). Provox complications were leakage, granulation tissue formation, malfunction and infection. The average survival time of Provox was longer in group C (9.2 me) than group A(8.6 m) or group B (7.3 me), but no statistical significance was found. The first time of Provox change was 10.2, 8.6 and 9.7 months respectively. The incidence of complication was not significantly different among groups. The cases of Provox remeval due to shunt failure were 5, 4 and 2 respectively. Even though a significant statistically difference was not found partialy due to the small numbers of patients, a special caution should be exercised in inserting Provox to prevent a serious complication for the patients who had a history of previous radiation.

• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.13-18
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• 2000

Recently due to the environmental pollution and the requirement for the substitute energy the interest for development of the solar energy system has been highly escalated It has been approved that the solar energy is a very useful on e because of purity and low cost. Some studies about the evaluation of solar radiation on the land has been carried out but few studies on the sea. This paper deals with a study on the evaluation of solar radiation on the sea. The experiments were carried out on the training vessel on the adjacent water of Korea Japan and China for twenty days. The distributions of solar radiation from the sea were changed into nonlinear in from according to the temperature. The solar radiation on the sea has a great influence on the velocity of wind as well as the temperature The distribuition of solar radiation has higher values on the track of the coastal sea than the open sea at same conditions.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.515-520
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• 2001

To observe the stimulating effect of low dose ${\gamma}$ radiation on the dormancy breaking and growth, microtubers of two potato cultivars (Solanum tuberosum L. cv. Dejima and cv. Superior) were irradiated at the dose of 0.5-30 Gy. Though it varied with cultivars and storage duration, sprouting rate, plant growth and tuber yield were promoted by 2-8 Gy irradiation in microtuber of 'Dejima' stored at low temperature. On the other hand, in microtuber of 'Superior', sprouting rate was promoted by 2 and 4 Gy irradiation, and the growth and tuber yield by 4 Gy irradiation. These results suggest that low dose of ${\gamma}$ radiation could have stimulating effects on the dormancy breaking of microtuber and potato growth.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.142-146
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• 2000

To observe the stimulating effects of low dose ${\gamma}-radiation$ on the seed germination, early growth and physiological activity in the gourd, seeds of three cultivars (Partner, Support, FR Yongja) were irradiated at the dose of $0.5{\sim}30\;Gy$. The hormetic effects of the low dose ${\gamma}-radiation$ on the growth were different from each cultivar. Low dose ${\gamma}-radiation$ had promoting effects on the germination at the optimum dose of 2 Gy and 8 Gy and on the early growth at the optimum dose of 4 Gy, 16 Gy and 20 Gy in Partner and Support cultivar and 1 Gy in FR Yongja cultivar. Irradiation didn't have significant effects on the chlorophyll contents of gourd plantlet. The antioxidant enzyme activity of gourd plantlet and early growth increased in low dose irradiation group.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.156-159
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• 1998

Germination rate and early growth in crop such as rice,soybean,and perilla were observed after irradiation of $^{\gamma}$-ray (Co-60) in order to determine the effects of low does radiation. The low dose radiation was able to improve the early growth in crops and their agricultural charaters. Germination rate of 2Gy-irradiatied rice seeds was high and also were seeding height and fresh weight of the 0.5 Gy-irradiated. Germination rate and early growth of soybean were high in 4Gy-irradiated group. Perilla gew ot so promisingly after after low dose irradiation,however there slightly increasing effects on germination rate, seeding height and fresh weightat 2Gt-, 1Gy-, and 1Gy irradiated group, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.1
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• pp.26-34
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• 2010

Effects of drying condition (IR radiation) on the optical properties and the printability of coated paper were elucidated at various latex sizes and low and high coating color concentrations. It was found that the smaller latex provided better rheology and higher dry and wet pick strength than the larger one. The high solids coating resulted in higher paper gloss and smaller roughness than the low solids coating, even though the clay addition was reduced by 20 parts in the high solids coating. Increasing IR radiation prohibited binder migration into the base paper. Thus it improved binder distribution and decreased pores in the coated layer, resulting in the increased dry and wet pick strength and the improved printing gloss. On the other hand, the color trapping and ink set-off was impaired with increasing IR radiation. Print mottle index passed through a maximum with increasing IR radiation.