• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.90-95
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• 2001

A continuum-based shape design sensitivity analysis (DSA) method is presented for the acoustic radiation from thin body. The normal derivative integral formulation is employed as an analysis formulation and differentiated directly by using material derivative to get the acoustic shape design sensitivity. In the acoustic sensitivity formulation, derivative coefficients of the structural normal velocities on the surface are required as the input. Thus, the shape design sensitivities of structural velocities on the surface with respect to the shape change are also calculated with continuum approach. A simple disk is considered as a numerical example to validate the accuracy and efficiency of the analytical shape design sensitivity equations derived in this research. This research should be very helpful to design an application involving thin body and to change its acoustic characteristics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.179-182
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• 2017

Cerebral nervous system intervention procedures have been reported frequently due to radiation exposure such as skin baldness, hair loss, and redness due to prolonged procedures. Therefore, the bismuth shield designed to reduce the radiation exposure of the target organ located in the anterior part of the human body sensitive to skin and radiation sensitivity during CT (computed tomography) scan is applied to the cerebral vascular system intervention by ergonomic design, To reduce the radiation dose of sensitive scalp, we propose a study.

• Journal of Genetic Medicine
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• v.19 no.1
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• pp.1-6
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• 2022

Radiation therapy (RT) is a very important treatment for cancer that irradiates a large amount of radiation to lead cancer cells and tissues to death. The progression of RT in the aspect of personalized medicine has greatly advanced over the past few decades in the field of technical precision responding anatomical characteristics of each patient. However, the consideration of biological heterogeneity that makes different effect in individual patients has not actually applied to clinical practice. There have been numerous discovery and validation of biomarkers that can be applied to improve the efficiency of radiotherapy, among which those related to genomic information are very promising developments. These genome-based biomarkers can be applied to identify patients who can benefit most from altering their therapeutic dose and to select the best chemotherapy improving sensitivity to radiotherapy. The genomics-based biomarkers in radiation oncology focus on mutational changes, particularly oncogenes and DNA damage response pathways. Although few have translated into clinically viable tools, there are many promising candidates in this field. In this review the prominent mutation-based biomarkers and their potential for clinical translation will be discussed.

• Journal of Radiation Protection and Research
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• v.15 no.2
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• pp.101-112
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• 1990

For the performance assessment of the radioactive waste disposal system (repository), a biosphere model is suggested. This biosphere model is intended to calculate the annual doses to man caused by the contaminated river water for eight pathways and four radionuclides. This model can also be applied to assess the radiological effects of contaminated well water. To account for the uncertainties on the model parameter values, parameter distributions are assigned to these model parameters. Then, Monte Carlo simulation method with Latin Hypercube sampling technique is used. Also, sensitivity analysis is performed by using the Spearman rank correlation coefficients. It is found that these methods are a very useful tool to treat uncertainties and sensitivities on the model parameter values and to analyze the biosphere model. A conversion factor is proposed to calculate the annual dose rate to humans arising from a unit radionuclide concentration in river water. This conversion factor allows for the substitution of the biosphere model in a probabilistic performance assessment computer code by one single variable.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.3 s.246
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• pp.270-277
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• 2006

Inverse radiation problems were solved for estimating boundary temperature distribution in a way of function estimation approach in an axisymmetric absorbing, emitting and scattering medium, given the measured radiative data. In order to reduce the computational time fur the calculation of sensitivity matrix, automatic differentiation and Broyden combined method were adopted, and their computational precision and efficiency were compared with the result obtained by finite difference approximation.. In inverse analysis, the effects of the precision of sensitivity matrix, the number of measurement points and measurement error on the estimation accuracy had been inspected using quasi-Newton method as an inverse method. Inverse solutions were validated with the result acquired by additional inverse methods of conjugate-gradient method or Levenberg-Marquardt method.

• Journal of Radiation Industry
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• v.8 no.2
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• pp.105-109
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• 2014

This study was conducted to investigate the sensitivity of Arthrobacter sp. PAMC 25486 to various mutagens. ${\gamma}-ray$, UV-ray, Ethyl methane sulfonate (EMS) and hydrogen peroxide ($H_2O_2$) were used as mutagen, and the survival rate of Arthrobacter sp. was measured at various doses of ${\gamma}-ray$ and UV-ray, and concentrations of EMS and $H_2O_2$. Decimal reduction dose ($D_{10}$ value) of Arthrobacter sp. was determined 370 Gy for a gamma irradiation treatment, 0.019 J for a UV ray, 2.5 mM for EMS, and 230 mM for $H_2O_2$. This result will be applied for the development of superior mutant strain of Arctic bacteria producing valuable compounds.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.17 no.1
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• pp.1-17
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• 1991

Multiport-600 Solar SimulatorR is one of the most recent and convenient in-strument for evaluation of sun protection factor(SPF). In this study, we examined the practicability of the SPF determining system using Multiport -600 and the effects of several factors-light sources, seasons and experimental animals-on the minimal erythema dose(MED) and SPF. We also tested the UV sensitivity according to the sites of Korean people, And the ultraviolet radiation reaching the earth's surface In Seoul have been observed for one year. As a result of this study, the determinig system for SPF using Multiport-600 was proved to be a good system in accuracy and time-saving. The biological activity of fluorescence UV lamp of PUVA-800R was significantly higher than natural light or solar simulator with Xe arc lamp, and the determined MED became lower in inverse proportion to room temperature rise. Skin sensitivity by ultraviolet adiation was hights. in order \circled1 back \circled2 inns, upper arm \circled3 outer upper arm \circled4 foream. We also observed that UV radiation intensity was highest at noon in july and 1 sun burn unit(MED) was 28 minutes at that time.

• Journal of radiological science and technology
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• v.14 no.1
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• pp.49-60
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• 1991

Thermoluminescent phosphors, which are now being used widely in radiation dosimetry, have an excellent sensitivity to ionizing radiation. In this study, thermoluminescent phosphors of $CaSO_4$ : Mn, $CaSO_4$ : Dy and $CaSO_4$ : Tm are prepared and their physical properties are investigated by measuring the trapping parameters and their luminescent spectra. By considering the sensitivity to X-ray and fading characteristics, $CaSO_4$ : Dy is most adequate to imaging plate. The imaging plate are prepared by coating the $CaSO_4$ : Dy powder on the Al substrate and its dose dependence is linear within the range of 40 mGy-20 Gy X-ray. The sensitivity of imaging plate depends linearly on the thickness of coated phosphor layer up to $35\;mg/cm^2$ and is independent on the grain size of the phosphor in the range of $70{\sim}250\;{\mu}m$. By photographing the imaging plate, X-ray images of the test object are obtained and better than those of X-ray films.

• Nuclear Engineering and Technology
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• v.38 no.3
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• pp.231-238
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• 2006

Whole-body exposure to high-dose radiation causes injury involving multiple organs that depends on their sensitivity to radiation. This acute radiation syndrome (ARS) is caused by a brief exposure of a major part of the body to radiation at a relatively high dose rate. ARS is characterized by an initial prodromal stage, a latent symptom-free period, a critical or manifestation phase that usually takes one of four forms (three forms): hematologic, gastrointestinal, or cardiovascular and neurological (neurovascular), depending upon the exposure dose, and a recovery phase or death. One of the most important factors in treating victims exposed to radiation is the estimation of the exposure dose. When high-dose exposure is considered, initial dose estimation must be performed in order to make strategy decisions for treatment as soon as possible. Dose estimation can be based on onset and severity of prodromal symptoms, decline in absolute lymphocyte count post exposure, and chromosomal analysis of peripheral blood lymphocytes. Moreover, dose assessment on the basis of calculation from reconstruction of the radiation event may be required. Experience of a criticality accident occurring in 1999 at Tokai-mura, Japan, showed that ARS led to multiple organ failure (MOF). This article will review ARS and discuss the possible mechanisms of MOF developing from ARS.

• Journal of Radiation Protection and Research
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• v.43 no.3
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• pp.114-119
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• 2018

Background: The retrospective dosimetry using RTL quartz can be improved by information for an optical sensitivity of sample connected with the equivalent dose determination. Materials and Methods: The quartz sample from a volcanic rock of Japan was used. After correcting the thermal quenching effect, RTL peaks of quartz were separated by the CGCD method cooperated with the general order kinetics. The number of overlapped glow peaks were ascertained by the $T_m-T_{stop}$ method. The optical sensitivity was examined by comparing the change of intensity on RTL glow peaks measured after exposure to light from a solar simulator with various illumination times. Results and Discussion: Seven glow peaks appeared to be overlapped on the RTL glow curve. The general order kinetics model was appropriate to separate glow peaks. After exposure to light from a solar simulator from a few minutes to 416 hr, the signals for peaks P4 and P5 decayed following the form of $f(t)=a_1e^{-{\lambda}1t}$, while the signals for peaks P6 and P7 decayed by the form of $f(t) = a_1e^{-{\lambda}1t}+a_2e^{-{\lambda}2t}+a_3e^{-{\lambda}3t}$. Conclusion: For dosimetric peaks, the times taken to reduce the RTL signal to half of its initial value were 70 sec for the peak P4, 54 s for the peak P5, 9,840 sec for the peak P6 and 26,580 sec for the peak P7, respectively. We conclude that the optical sensitivity of peaks P4, and P5 gives much higher than that of peaks P6 and P7.