• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.443-447
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• 2014

$^{134}Cs$ radioactive concentration among soil samples is difficult to classify due to the background impact on crust originated natural radioactive nuclide, and overlapping and interfering between peaks. The ways to identify true peaks in gamma-ray spectroscopy are as follows to reduce statistical fluctuation by smoothing based on the fact that the shapes of peak are mostly Gaussian, to inspect the levels of width and height of peaks, to add functions on low-energy trailing phenomena, or 4) to check the peaks after modifying Gaussian function itself. Therefore, it is considered that information and knowledge for spectrum analysis are necessary.

• The Korean Journal of Applied Statistics
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• v.26 no.4
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• pp.569-579
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• 2013

In the field of single-molecule spectroscopy, it is essential to analyze luminescence Intensity changes that result from a single molecule. With the CdSe/ZnS core-shell structured quantum dot photon emission data Bayesian multiple change-point estimation is done with the gamma prior for Poisson parameters and truncated Poisson distribution for the number of change-points.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.133-138
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• 2018

The measurement of gamma-ray spectrum of $^{nat}W(p,xn)$ reaction with natural tungsten were performed by using a high energy proton generated from a 100-MeV proton linear accelerator of the Korea Multi-purpose Accelerator Complex (KOMAC). Gamma rays generated by various nuclides generated through the nuclide were measured using a gamma-ray spectroscopy system composed of HPGe detector. A gamma-ray standard source was used for energy calibration and efficiency measurement of the detector. Analysis of the gamma rays observed in the measured spectra showed that the radionuclides produced were $^{167}Re$, $^{178}Re$, $^{179}Re$, $^{180}Re$, $^{181}Re$, $^{182}Re$, $^{184}Re$, $^{172}Ta$, $^{174}Ta$, $^{178}Ta$, $^{182}Ta$, $^{184}Ta$, $^{175}W$, $^{176}W$, $^{177}W$ and $^{179}W$. Nuclides were generated. The results of this study will be applied to nuclear fusion, astrophysics, and nuclear medicine applications in the future.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.321-326
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• 1994

The water-soluble polyphosphazene possessing ether side groups was exposed to ${\gamma}-rays$ to prepare hydrogens with good water-swellability. The physical strength of these hydrogels could be controlled by irradiation dose of ${\gamma}-rays$. Trypsin and water-soluble polyphosphazene were irradiated together by ${\gamma}-rays$ for entrapment of enzymes into hydrogel networks. The activities of immobilized trypsin were examined spectrophotometrically after the reaction with N-${\alpha}$-benzoyl-1-arginine-p-nitroanilide in phosphate buffer. The immobilized trypsin was found to have good activity yield and suability after at least 500 hours.

• Analytical Science and Technology
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• v.16 no.1
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• pp.39-47
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• 2003

The measurement of radium ($^{226}Ra$) in the groundwater was established using ${\gamma}$-ray spectroscopy without sample preparation. The background interference by air borne radon daughter nuclides was reduced by $N_2$ gas flow into the counting chamber. Leakage of radon gas produced in the radioactive equilibrium with radium and its daughter nuclides was prevented by use of the air-tighted aluminium container. We investigated the effect of air layer in the counting container. Radioactivity variation due to emanation of radon into the air layer was within the counting error range 5%. When the nitrogen gas was flowed around the detector, peak counts of ${\gamma}$-rays from the daughters of airborne radon was decreased and detection limit was decreased to 0.02 Bq/L. The detection limit of detector was lower than 0.74 Bq/L, the $^{226}Ra$ Maximum Contaminant Level (MCL) in the groundwater proposed by US Environmental Protection Agency (EPA). It was confirmed that $^{226}Ra$ radioactivity in the groundwater could be determined by the ${\gamma}$-ray spectroscopy.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.377-384
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• 2005

Since gamma-ray bursts(GRBs) have been first known to science societites in 1973, many scientists are involved in their studies. Observations of GRB afterglows provide us with much information on the environment in which the observed GRBs are born. Study of GRB afterglows deals with longer timescale emissions in lower energy bands (e.g., months or even up to years) than prompt emissions in gamma-rays. Not all the bursts accompany afterglows in whole ranges of waveleogths. It has been suggested as a reason for that, for instance, that radio and/or X-ray afterglows are not recorded mainly due to lower sensitivity of detectors, and optical afterglows due to extinctions in intergalactic media or self-extinctions within a host galaxy itself. Based on the idea that these facts may also provide information on the GRE environment, we analyze statistical properties of GRB afterglows. We first select samples of the redshift-known GRBs according to the wavelength of afterglow they accompanied. We then compare their distributious as a function of redshift, using statistical methods. As a results, we find that the distribution of the GRBs with X-ray afterglows is consistent with that of the GRBs with optical afterglows. We, therefore, conclude that the lower detection rate of optical afterglows is not due to extinctions in intergalactic media.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2006.11a
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• pp.363-364
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• 2006

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.287-287
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• 2011

동시 계수 도플러 넓어짐 양전자 소멸 분광법으로 n, p형 Cz-Si의 시료에 양성자를 0, 4 MeV 에너지와 조사량의 변화에 의한 결함을 측정하였으며, 고체 구조 특성에 대하여 조사하였다. 양전자와 전자의 쌍소멸로 발생하는 511 keV 감마선 스펙트럼의 수리적 해석 방법인 S-변수와 W-변수를 사용하여, 구조 변화를 측정하였다. 양성자 조사에너지의 세기에 따라 결함이 증가하였으며, 양성자의 조사량의 변화에 대하여는 큰 변화가 없었다.

• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.92-98
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• 2004

DBPAS has been used to characterize atomic size defect structures in materials. In this investigation the numerical analysis of the Doppler spectra was employed to the determination of the shape parameter, S, defined as the ratio between the amount of counts in a central portion of the spectrum and the total counts of whole spectrum. As the samples were exposed by X-ray increasing the exposed doses from 3, 6, and 9 Gy with 6 MV and 15 MV, respectively and also irradiated by X-ray as the medical applications used for in 0, 2, 4 and 6 years. The S-parameter values were increased as increasing the exposed time and the energies, that indicated the defects generate more. The S-parameters of the samples with medical treatment is varied from 0.4932 to 0.4956.

• Journal of the Korean Magnetics Society
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• v.21 no.1
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• pp.5-9
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• 2011

M$\ddot{o}$ssbauer and Raman spectrum studies have been carried out on the 2b-site Fe ion in the Ba-ferrite (M-type). The thermal dynamics of Fe ion was analyzed by M$\ddot{o}$ssbauer spectra at different angles between the $\gamma$-ray direction and c-axis. The vibration on the 2b-site was more active compare to other direction and had very strong intensity in the Raman spectrum.