• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1754-1759
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• 2022

The activity of gamma-ray emitting nuclides is calculated assuming that each gamma-ray is detected individually; thus, the magnitude of the coincidence summing signal must be considered during activity calculations. Here, the correction factor for the coincidence summing effect was calculated, and the detection efficiencies of two HPGe detectors were compared. The CANBERRA Inc. GC4018 high-purity Ge detector provided an estimate for the peak-to-total ratio using a point source to determine the coincidence summing correction factor. The ORTEC Inc. GEM60 high-purity Ge detector uses EFFTRAN in LVis to obtain the parameters of the detector and source model and the gamma-gamma and gamma-X match estimates, in order to determine the coincidence summing correction factor. Nuclide analyses, radioactivity comparisons, and analyses of reference material samples were performed utilizing certified reference materials to accurately determine the detection efficiencies. For both Co-60 and Y-88, the detection efficiency for a point source increased by an average of at least 12-13%, whereas the detection efficiency determined using LVis increased by an average of at least 13-15%. The calculated radioactivity values of the certified reference material and reference material samples were accurate to within 3% and 6% of the measured values, respectively.

• Journal of applied mathematics & informatics
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• v.26 no.1_2
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• pp.29-44
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• 2008

By employing the continuation theorem of coincidence degree theory, we derive a sufficient condition for the existence and attractricity of a positive periodic solution for a generalized predator-prey model with diffussion feedback controls.

• Journal of the Korean Mathematical Society
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• v.36 no.2
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• pp.243-256
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• 1999

We will consider f,g : S1longrightarrowS2 a pair of maps between two orientable compact surfaces. The purpose of this paper is to decide when the pair can be deformed to a pair (f', g') such that

• East Asian mathematical journal
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• v.22 no.2
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• pp.195-205
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• 2006

Using the notion of anti fuzzy points and its besideness to and non-quasi-coincidence with a fuzzy set, new concepts of an anti fuzzy subgroup are introduced and their inter-relations are investigated.

• Communications of the Korean Mathematical Society
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• v.13 no.1
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• pp.109-121
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• 1998

Let X,Y be connected, locally connected, semilocally simply connected and $f,g : X \to Y$ be a pair of maps. We find an upper bound of the Reidemeister number R(f,g) by using the regular coverig spaces.

• Journal of Information Technology Services
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• v.12 no.3
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• pp.273-287
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• 2013

The objective of this study is to empirically develop performance evaluation measures for LIS (logistics information systems) based upon BSC (balanced scorecard) model and determine the relative importance among four perspectives of BSC using AHP (analytic hierarchy process) methodology. Above all, forty nine probable measures for evaluating LIS performance were identified through reviewing the previous research related with SCM (supply chain management), logistics management, and information systems evaluation. And then, these probable measures were examined by means of coincidence analyses using three mutually exclusive criteria(validity of content, ease of measurement and reliability of measurement). Data for conducting the coincidence analyses were collected from LIS users and LIS development personnel. As the results of the coincidence analyses, it was found that 31 ones among 49 probable performance evaluation measures theoretically derived could be qualified for LIS performance evaluation. And AHP analysis showed that the weight of each perspective was respectively as follows : 46.8% for financial perspective, 31.3% for customer perspective, 14.8% for internal business process perspective, and 7.1% for learning and growth perspective. The academic contribution of this study is that performance evaluation measures for LIS could be systematically and empirically developed on the basis of BSC. Also, the results of this study are expected to be used as a practice guideline of evaluating and improving LIS.

• Women's Health Nursing
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• v.13 no.2
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• pp.98-104
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• 2007

Purpose: The purpose of this study was to explore the barriers and the enhancing factors and predictors to postpartum care performance. Methods: The Research design in this study was a cross-sectional correlational survey. Subjects were 145 women at 6 to 10 weeks post delivery at an OB & GY clinic. Data was gathered with postpartum care performance, and other related variables including emotional status during pregnancy, fatigue, health recovery status, maternal role and identity. Data was analyzed using the SPSS WIN(version 11.0) program. Results: The mean score of postpartum care performance was 3.08 of 5, it had significant differences in emotional status during pregnancy, coincidence of expected sex, health recovery status, postpartum fatigue and postpartum depression. The maternal role and health recovery status were enhancing factors of postpartum care performance. Also, the barrier factors were fatigue, depression and coincidence of expected sex. Among these factors, the present health recovery status had an predictability of 11.7%, postpartum fatigue 3.2%, and coincidence of expected sex 2.5%, for a total predictability factor of 17.4% on postpartum care performance. Conclusion: Among these related factors to postpartum care performance, present health recovery status was the most predictable factor and then postpartum fatigue, and coincidence of expected sex. We need to establish a strategy to reduce postpartum fatigue and implement nursing interventions for health related consequences in postpartum women.

• Korean Journal of Optics and Photonics
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• v.16 no.6
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• pp.481-484
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• 2005

Quantum ghost imaging uses quantum mechanically entangled photons to form an image of an object. The quantum ghost image is also obtained by means of classical coincidence measurements with a classically correlated light source[1,2]. In this work we performed classical coincidence imaging experiments with classically correlated beams in their direction of propagation. We observed the ghost interference patterns which were usually made by quantum mechanically entangled states and we also analyze in detail the mechanism of the ghost imaging with classically correlated lights. We made? the classically correlated source with an Ar laser and controlled the direction of the light by a mirror? mounted on a small speaker.

• Journal of radiological science and technology
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• v.22 no.1
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• pp.5-11
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• 1999

This paper reviews recent major activities on instrumentation and methodology of PET. The performance of the PET instrumentation can be expressed by four physical characteristics, 1) spatial resolution, 2) coincidence resolving time, 3) energy resolution, and 4) detection efficiency. The physical and technical aspects of PET systems are briefly discussed along with these characteristics. Toward high resolution PET the recent trend has been to design multiple rings of densely packed detector arrays with scintillators. In order to satisfy the sampling requirement in reconstruction, continuous detector units has been developed. Iterative image reconstruction algorithms have received considerable attention for improvement of both the sampling requirement and image quality toward the stationary PET. Better resolving time improves the maximum true coincidence rate, which is also increased with more detectors placed in coincidence with each other. It suggests that volume PET is promising for enhancement of detection efficiency. The scattered coincidence event rate may be reduced by using detectors with better energy resolution. The use of interplane septa, however, takes over improvement of energy resolution in 2D PET. Energy resolution becomes an important factor for image quality under the condition of septa removal such as volume PET. Toward full utilization of emitting photons, 3D reconstruction incorporating oblique rays has been studied, and volume reconstruction algorithms have been developed. Practical volume PET systems impose heavy burden not only to detector sets and coincidence circuits, but also to computers in the memory requirements and the data processing. In conclusion, there have been many ingenious methods in development of PET instrumentation, which are based on unique capability of PET. They will be expected to overcome technical limitations, and to approach the fundamental limits.

• Spatial Information Research
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• v.12 no.1
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• pp.43-56
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• 2004

Basically a land parcel consists of a land parcel number, land category, land boundary and area, and land value is mostly determined by the land category. Generally people want to change their land use to increase their land value so that they can expect more benefits from the land. However, changing land use causes several problems with land properties, haphazard urban expansions and land category non-coincidences. Unfortunately, no effective solutions exist for land category non-coincidence problems. In this study, we proposed a methodology that can classify the land category based land covers using high resolution satellite images and digital topographic maps. For this, we obtained a parcel based land use/cover classification map. Using both this classification map and a digital cadastral map, we inspected land category non-coincidences. As a result, land category non-coincidence rates could be statistically measured and interpreted and demonstrate a possibility that we could quantitatively interpretate and measure cadastral non-coincidence automatically.