• Journal of the Korean Physical Society
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• v.80
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• pp.516-525
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• 2022

This study is to assess the clinical use of commercial PerFRACTION^TM for patient-specific quality assurance of volumetric-modulated arc therapy. Forty-six pretreatment verification plans for patients treated using a TrueBeam STx linear accelerator for lesions in various treatment sites such as brain, head and neck (H&N), prostate, and lung were included in this study. All pretreatment verification plans were generated using the Eclipse treatment planning system (TPS). Dose distributions obtained from electronic portal imaging device (EPID), ArcCHECK^TM, and two-dimensional (2D)/three-dimensional (3D) PerFRACTION^TM were then compared with the dose distribution calculated from the Eclipse TPS. In addition, the correlation between the plan complexity (the modulation complexity score and the leaf travel modulation complexity score) and the gamma passing rates (GPRs) of each quality assurance (QA) system was evaluated by calculating Spearman's rank correlation coefficient (r_s) with the corresponding p-values. The gamma passing rates of 46 patients analyzed with the 2D/3D PerFRACTION^TM using the 2%/2 mm and 3%/3 mm criteria showed almost similar trends to those analyzed with the Portal dose imaging prediction (PDIP) and ArcCHECK^TM except for those analyzed with ArcCHECK^TM using the 2%/2 mm criterion. Most of weak or moderate correlations between GPRs and plan complexity were observed for all QA systems. The trend of mean rs between GPRs using PDIP and 2D/3D PerFRACTION^TM for both criteria and plan complexity indices as in the GPRs analysis was significantly similar for brain, prostate, and lung cases with lower complexity compared to H&N case. Furthermore, the trend of mean rs for 2D/3D PerFRACTION^TM for H&N case with high complexity was similar to that of ArcCHECK^TM and slightly lower correlation was observed than that of PDIP. This work showed that the performance of 2D/3D PerFRACTION^TM for pretreatment patient-specific QA was almost comparable to that of PDIP, although there was small difference from ArcCHECK^TM for some cases. Thus, we found that the PerFRACTION^TM is a suitable QA system for pretreatment patient-specific QA in a variety of treatment sites.

• Journal of the Korean Home Economics Association
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• v.27 no.1
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• pp.165-179
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• 1989

The purpose of this study is to examine the difference between wife and husband in the level of stress recognition and distress subsequent to the life events, and thus 5 kinds of study questions have been established for the achievement of this purpose. Data were obtained from 371 couples who resided in Seoul through Likert-Type questionaire, and Frequency, Percentage, Mean, T-Test, One Way ANOVA, Pearson ${\gamma}$ Correlation, Multiple Regression, Cronbach ${\alpha}$ Coefficient were calculated. As the result of this studay, the experiences subsequent to life events, the level stress recognition and distress was different from wife and husband, and it was generally shown that those are higher for wife rather than husband.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.37-44
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• 1997

A dadaptive refinement tetrahedron mesh has been presented for using in full band GaAs monte carlo simulation. A uniform tetrahedron mesh is used without regard to energy values and energy variety in case of the past full band simulation. For the uniform tetrahedron mesh, a fine tetrahedron is demanded for keeping up accuracy of calculation in the low energy region such as .GAMMA.-valley, but calculation time is vast due to usin gthe same tetrahedron in the high energy region. The mesh of this study, thererfore, is consisted of the fine mesh in the low energy and large variable energy region and rough mesh n the high energy. The density of states (DOS) calculated with this mesh is compared with the one of the uniform mesh. The DOS of this mesh is improved th efive times or so in root mean square error and the ten times in the correlation coefficient than the one of a uniform mesh. This refinement mesh, therefore, can be used a sthe basic mesh for the full band GaAs monte carlo simulation.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.176-177
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• 2014

The new algorithm was proposed to quantify symmetry recorded in convergent beam electron diffraction (CBED) patterns and symmetry mapping. The proposed algorithm is based on the normalized cross-correlation coefficient (${\gamma}$) for quantifying the amount of symmetry in a CBED pattern. The quantification and mapping procedures are automatically controlled by the script implemented in Gatan Digital Micrograph$^{(c)}$. We apply the quantitative CBED measurement to a strained Si sample to test the sensitivity to defects.

• Nutrition Research and Practice
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• v.13 no.3
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• pp.196-204
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• 2019

BACKGROUND/OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is a common metabolic disease triggered by epigenetic alterations, including lysine acetylation at histone or non-histone proteins, affecting the stability or transcription of lipogenic genes. Although various natural dietary compounds have anti-lipogenic effects, their effects on the acetylation status and lipid metabolism in the liver have not been thoroughly investigated. MATERIALS/METHODS: Following oleic-palmitic acid (OPA)-induced lipid accumulation in HepG2 cells, the acetylation status of histone and non-histone proteins, HAT activity, and mRNA expression of representative lipogenic genes, including $PPAR{\gamma}$, SREBP-1c, ACLY, and FASN, were evaluated. Furthermore, correlations between lipid accumulation and HAT activity for 22 representative natural food extracts (NExs) were evaluated. RESULTS: Non-histone protein acetylation increased following OPA treatment and the acetylation of histones H3K9, H4K8, and H4K16 was accelerated, accompanied by an increase in HAT activity. OPA-induced increases in the mRNA expression of lipogenic genes were down-regulated by C-646, a p300/CBP-specific inhibitor. Finally, we detected a positive correlation between HAT activity and lipid accumulation (Pearson's correlation coefficient = 0.604) using 22 NExs. CONCLUSIONS: Our results suggest that NExs have novel applications as nutraceutical agents with HAT inhibitor activity for the prevention and treatment of NAFLD.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.358-358
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• 2012

The application of BZO (Boron-doped Zinc Oxide) films use as the TCO(Transparent Conductive Oxide) material for display and solar cell industries, where the conductivity of the BZO films plays a critical role for improvement of cell performance. Thin BZO films are deposited on glass substrates by using RF sputter system. Then charging flow rates of O2 gas from zero to 10 sccm, thereby controlling the impurity concentration of BZO. BZO deposited on soda lime glass and RF power was 300 W, frequency was 13.56 MHz, and working pressure was $5.0{\times}10-6$ Torr. The Substrate and glass between distance 200 mm. We measured resistivity, conductivity, mobility by hall measurement system. Optical properties measured by photo voltaic device analysis system. We measured surface build according to oxygen flow rate from XPS (X-ray Photoelectron Spectroscopy) system. The profile of the energy distribution of the electrons emitted from BZO films by the Auger neutralization is measured and rescaled so that Auger self-convolution arises, revealing the detail structure of the valence band. It may be observed coefficient ${\gamma}$ of the secondary electron emission from BZO by using ${\gamma}$-FIB (Gamma-Focused Ion Beam) system. We observed the change in electrical conductivity by correlation of the valence band structure. Therefore one of the key issues in BZO films may be the valence band that detail structure dominates performance of solar cell devices. Demonstrating the secondary electron emission by the Auger neutralization of ions is useful for the determination of the characteristics of BZO films for solar cell and display developments.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.1
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• pp.117-126
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• 2006

The purpose of this study is to develop a badge-type passive sampler for the measurement of short-term nitrogen dioxide and to evaluate its performance. The principle of the method is a colorimetric reaction of nitrogen dioxide with sulfanilic acid, N-1-naphthylethylendiamine, and phosphoric acid. First, it has been shown that the filter paper should be rinsed with ultrapure water and ultrasound, and then dried in a vacuumed desiccator. The concentration and volume of absorption reagent (triethanolamine) were $20\%$ and 100 ${\mu}L$, respectively. The extraction time was determined as 60 min. Second, duplicate measurements (n= 116) were carried out for evaluating the precision of the passive sampler. The relative error and the correlation coefficient between duplicates are $3.4\pm 3.0\%$ and 0.994, respectively. In addition, the $95\%$ confidence interval of intraclass correlation coefficient and the estimated value are 0.992$\sim$0.996 and 0.994, respectively. Third, a paired t-test was carried out for evaluating the accuracy of the passive sampler (n=40). In the result of the test, the $95\%$ confidence interval of the difference was -1.710 ppb <$\gamma$< 0.788 ppb. Finally, the average concentration of blanks, measurement detection limit, limit of detection, and limit of quantification are $2.4\pm 0.4$ ppb, 104 ppb, 3.8 ppb, and 7.0 ppb, respectively.

• Journal of Distribution Research
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• v.15 no.4
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• pp.61-85
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• 2010

Introduction: Diffusion is process by which an innovation is communicated through certain channel overtime among the members of a social system(Rogers 1983). Bass(1969) suggested the Bass model describing diffusion process. The Bass model assumes potential adopters of innovation are influenced by mass-media and word-of-mouth from communication with previous adopters. Various expansions of the Bass model have been conducted. Some of them proposed a third factor affecting diffusion. Others proposed multinational diffusion model and it stressed interactive effect on diffusion among several countries. We add a spatial factor in the Bass model as a third communication factor. Because of situation where we can not control the interaction between markets, we need to consider that diffusion within certain market can be influenced by diffusion in contiguous market. The process that certain type of retail extends is a result that particular market can be described by the retail life cycle. Diffusion of retail has pattern following three phases of spatial diffusion: adoption of innovation happens in near the diffusion center first, spreads to the vicinity of the diffusing center and then adoption of innovation is completed in peripheral areas in saturation stage. So we expect spatial effect to be important to describe diffusion of domestic discount store. We define a spatial diffusion model using multinational diffusion model and apply it to the diffusion of discount store. Modeling: In this paper, we define a spatial diffusion model and apply it to the diffusion of discount store. To define a spatial diffusion model, we expand learning model(Kumar and Krishnan 2002) and separate diffusion process in diffusion center(market A) from diffusion process in the vicinity of the diffusing center(market B). The proposed spatial diffusion model is shown in equation (1a) and (1b). Equation (1a) is the diffusion process in diffusion center and equation (1b) is one in the vicinity of the diffusing center. $$\array{{S_{i,t}=(p_i+q_i{\frac{Y_{i,t-1}}{m_i}})(m_i-Y_{i,t-1})\;i{\in}\{1,{\cdots},I\}\;(1a)}\\{S_{j,t}=(p_j+q_j{\frac{Y_{j,t-1}}{m_i}}+{\sum\limits_{i=1}^I}{\gamma}_{ij}{\frac{Y_{i,t-1}}{m_i}})(m_j-Y_{j,t-1})\;i{\in}\{1,{\cdots},I\},\;j{\in}\{I+1,{\cdots},I+J\}\;(1b)}}$$ We rise two research questions. (1) The proposed spatial diffusion model is more effective than the Bass model to describe the diffusion of discount stores. (2) The more similar retail environment of diffusing center with that of the vicinity of the contiguous market is, the larger spatial effect of diffusing center on diffusion of the vicinity of the contiguous market is. To examine above two questions, we adopt the Bass model to estimate diffusion of discount store first. Next spatial diffusion model where spatial factor is added to the Bass model is used to estimate it. Finally by comparing Bass model with spatial diffusion model, we try to find out which model describes diffusion of discount store better. In addition, we investigate the relationship between similarity of retail environment(conceptual distance) and spatial factor impact with correlation analysis. Result and Implication: We suggest spatial diffusion model to describe diffusion of discount stores. To examine the proposed spatial diffusion model, 347 domestic discount stores are used and we divide nation into 5 districts, Seoul-Gyeongin(SG), Busan-Gyeongnam(BG), Daegu-Gyeongbuk(DG), Gwan- gju-Jeonla(GJ), Daejeon-Chungcheong(DC), and the result is shown