• Journal of Radiation Protection and Research
• /
• 제43권4호
• /
• pp.137-142
• /
• 2018

Background: Gamma-ray detectors having a thin window of a material with low atomic number can increase the true coincidence summing effects for radionuclides emitting X-rays or gamma-rays. This effect can make efficiency calibration or spectrum analysis more complicated. In this study, a Cu shield was tested as an X-ray filter to neglect the true coincidence summing effect by X-rays and gamma-rays in gamma-ray spectrometry, in order to simplify gamma-ray energy spectrum analysis. Materials and Methods: A Cu shield was designed and applied to an n-type high-purity germanium detector having an $X-{\gamma}$ summing effect during efficiency calibration. This was tested using a commercial, certified mixed gamma-ray source. The feasibility of a Cu shield was evaluated by comparing efficiency calibration results with and without the shield. Results and Discussion: In this study, the thickness of a Cu shield needed to avoid true coincidence summing effects due to $X-{\gamma}$ was tested and determined to be 1 mm, considering the detection efficiency desired for higher energy. As a result, the accuracy of the detection efficiency calibration was improved by more than 13% by reducing $X-{\gamma}$ summing. Conclusion: The $X-{\gamma}$ summing effect should be considered, along with ${\gamma}-{\gamma}$ summing, when a detection efficiency calibration is implemented and appropriate shielding material can be useful for simplifying analysis of the gamma-ray energy spectra.

• 한국치위생학회지
• /
• 제18권6호
• /
• pp.1047-1055
• /
• 2018

Objectives: The purpose of this study was to compare the author key words and MeSH (Medical Subject Headings) terms in the Journal of Korean Society of Dental Hygiene (JKSDH). Methods: A total of 3,242 author key words from 974 informative articles published from 2001 to 2015 were compared with MeSH terms, according to the criteria of complete coincidence, incomplete coincidence, and complete non-coincidence. Results: The coincidence rate of 564 author key words with MeSH terms was 17.4%. The author key words that appeared most frequently (in descending order) were oral health (41 times), dental hygienists (30 times), dental caries (29 times), and knowledge (29 times). There was a non-coincidence rate of 70.5% for 2,286 author key words with MeSH terms. Conclusions: Many author key words used in the JKSDH did not coincide with MeSH terms. The use of author key words that coincide with MeSH terms is necessary to accomplish the international journal.

• 대한수학회논문집
• /
• 제32권2호
• /
• pp.375-387
• /
• 2017

In this paper, we prove some coincidence point theorems involving ${\varphi}-contraction$ in ordered partial metric spaces. We also extend newly introduced notion of g-comparability of a pair of maps for linear contraction in ordered metric spaces to non-linear contraction in ordered partial metric spaces. Thus, our results extend, modify and generalize some recent well known coincidence point theorems of ordered metric spaces.

• 대한수학회보
• /
• 제33권2호
• /
• pp.205-211
• /
• 1996

Throughout this paper, we will work in the category of compact connected manifolds and continuous maps. If $X_1, X_2$ are manifolds, $f, g: X_1 \to X_2$ are maps, then a point $x \in X_1$ is a coincidence of f and g iff f(x) = g(x) ; the set of all such points is denoted by Coin(f,g).

• Korean Journal of Mathematics
• /
• 제15권1호
• /
• pp.39-49
• /
• 2007

A few existence results of nonunique coincidence points for some kinds of $\acute{C}$iri$\acute{c}$ type mappings in metric and pseudocompact Tichonov spaces, respectively, are proved. The results presented in this paper extend some known results in the literature.

• 대한수학회지
• /
• 제32권2호
• /
• pp.171-181
• /
• 1995

Nielsen coincidence theory is concerned with the estimation of a lower bound for the number of coincidences of two maps $f,g: X \longrightarrow Y$. For this purpose the so-called Nielsen number N(f,g) is introduced, which is a lower bound for the number of coincidences ([1]). The relative Nielsen number N(f : X,A) in the fixed point theory is introduced in [3], which is a lower bound for the number of fixed points for all maps in the relative homotopy class of f:(X,A) $\longrightarrow$ (X,A), and its estimation is given in [5].

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제27권1호
• /
• pp.61-70
• /
• 2020

In this paper, we introduce a new concept of stability of coincidence iterative algorithm for three mappings and derive a new three-step Jungck-type iterative algorithm. And, we prove a stability result and a strong convergence result for the Jungck-type algorithm using the M_J-contractive condition. Our results extend and unify the corresponding ones in [3, 6, 7, 13].

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제27권3호
• /
• pp.109-124
• /
• 2020

We establish coincidence point theorem for S-non-decreasing mappings under Geraghty-type contraction on partially ordered metric spaces. With the help of obtain result, we derive two dimensional results for generalized compatible pair of mappings F, G : X² → X. As an application, we obtain the solution of integral equation and also give an example to show the usefulness of our results. Our results improve, sharpen, enrich and generalize various known results.

• East Asian mathematical journal
• /
• 제18권1호
• /
• pp.147-154
• /
• 2002

In this paper, we prove a few coincidence point theorems for two pairs of mappings in $T_1$ topological spaces. Our results extend, improve and unify the corresponding results in [1]-[3].

• Journal of applied mathematics & informatics
• /
• 제37권1_2호
• /
• pp.1-11
• /
• 2019

In this paper we prove certain coupled coincidence point and coupled common fixed point results in partially ordered metric spaces for a pair of compatible mappings which satisfy certain rational inequality. The results are supported with two examples.