• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.291-293
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• 2002

Accurate dose calculation in radiation treatment planning is most important for successful treatment. Since human body is composed of various materials and not an ideal shape, it is not easy to calculate the accurate effective dose in the patients. Many methods have been proposed to solve the inhomogeneity and surface contour problems. Monte Carlo simulations are regarded as the most accurate method, but it is not appropriate for routine planning because it takes so much time. Pencil beam kernel based convolution/superposition methods were also proposed to correct those effects. Nowadays, many commercial treatment planning systems, including Pinnacle and Helax-TMS, have adopted this algorithm as a dose calculation engine. The purpose of this study is to verify the accuracy of the dose calculated from pencil beam kernel based treatment planning system Helax-TMS comparing to Monte Carlo simulations and measurements especially in inhomogeneous region. Home-made inhomogeneous phantom, Helax-TMS ver. 6.0 and Monte Carlo code BEAMnrc and DOSXYZnrc were used in this study. Dose calculation results from TPS and Monte Carlo simulation were verified by measurements. In homogeneous media, the accuracy was acceptable but in inhomogeneous media, the errors were more significant.

• The Plant Pathology Journal
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• v.34 no.5
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• pp.347-355
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• 2018

Fusarium head blight (FHB) caused by Fusarium species is a major disease of wheat and barley around the world. FHB causes yield reductions and contamination of grains with trichothecene mycotoxins including; nivalenol (NIV), deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON), and 15-acetyldeoxynivalenol (15-ADON). The objectives of this study were to identify strains of F. graminearum isolated in Korea from 2012-harvested wheat grain and to test the pathogenicity of these NIV- and DON-producing isolates. Three hundred and four samples of wheat grain, harvested in 2012 in Chungnam, Chungbuk, Gyeongnam, Jeonbuk, Jeonnam, and Gangwon provinces were collected. We recovered 44 isolates from the 304 samples, based on the PCR amplification of internal transcribed spacer (ITS) rRNA region and sequencing. Our findings indicate that F. asiaticum was the predominant (95% of all isolates) species in Korea. We recovered both F. asiaticum and F. graminearum from samples collected in Chungnam province. Of the 44 isolates recovered, 36 isolates had a NIV genotype while 8 isolates belonged to the DON genotype (3-ADON and 15-ADON). In order to characterize the pathogenicity of the strains collected, disease severity was assessed visually on various greenhouse-grown wheat cultivars inoculated using both NIV- and DON-producing isolates. Our results suggest that Korean F. graminearum isolates from wheat belong to F. asiaticum producing NIV, and both F. graminearum and F. asiaticum are not significantly different on virulence in wheat cultivars.

• Korean Journal of Health Education and Promotion
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• v.28 no.3
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• pp.31-42
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• 2011

Objectives: Busan had the highest mortality and the shortest life expectancy at birth among 16 provinces in Korea in 2008 and there were considerable health inequalities within the region. This study was performed to build up a priority setting framework in Healthy City Busan project. Methods: Analytic hierarchy process was used to determine the relative priority weight for different strategic and program dimensions along with the consistency of response. An on-site workshop-based meeting (calculating importance) and online survey (calculating risk) were conducted to obtain data from 8 experts. Results: The results showed that in strategic criteria "active health promotion & diseases prevention" and "building infrastructure for the Health City project" were two most important factors. In program criteria, considering both importance and risk scores, "making a healthy community" and "building community health centers" in disadvantaged areas were a top priority group. In addition, "enacting an ordinance for the Healthy City", "building the infrastructure for health impact assessment" and "making health care safety net for vulnerable population" were also higher priorities group. Conclusions: Our findings suggest that the Healthy City project in Busan should be focused on strengthening health equity and building infrastructure for sustainability of the project.

• Economic and Environmental Geology
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• v.29 no.4
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• pp.483-493
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• 1996

The tectonic environment and source characteristics of the Daebo granitic batholith in the central Ogcheon Belt were investigated based upon major and trace element geochemistry. The batholith is comprised of three granite types; a biotite granite (DBBG), K-feldspar megacryst-bearing biotite granite (DBKG), and a more mafic granodiorite (DBGD). The variations of Na and K in the granites can not be explained by simple fractional crystallization from the same primary magma. The irregular behavior of these alkali elements indicates a variety of source materials or incomplete mixing of different source materials. The large ion lithophile (LIL) element enrichment and low Ta/Hf ratios of the granites are typical characteristics of normal, calc-alkaline continental arc granitoids. Based upon REE patterns of the granites, it seems to be unreasonable to regard the felsic DBBG as a late stage differentiate formed by residual melts after the fractionation of major constituent minerals of the more mafic DBGD. Inconsistent variations in ${\varepsilon}_{Nd}(t)$ and LIL element concentrations of the granites preclude a mixing model between primitive melt and LIL element-enriched upper crustal materials. The irregular geochemical variation of the granites is taken to be largely inherited from an already heterogeneous source region.

• Journal of Korean Society of Steel Construction
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• v.12 no.3 s.46
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• pp.231-238
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• 2000

There was extreme improvement in the processing result of weld toe, but there is possibility that the fatigue failure occurs from the weld root part where the fatigue strength became low relatively. This study did the fatigue test at the cross rib specimens which implemented a partial penetration weld to improve the fatigue strength of the weld root part. As a result of the fatigue test of the partial penetration weld and the fillet weld specimens, almost the same fatigue strength appeared. Because the fatigue failure began from toe, there was not a reinforcement effect in the weld root part by the partial penetration weld. So, it examined fatigue strength at the partial penetration welding specimens which processed toe to stop the fatigue failure of toe part. As a result, there was big fatigue strength improvement from the partial penetration weld than the fillet weld. Therefore, if fatigue crack occurrence can be restrained from toe, it thinks that the fatigue strength of the root part can improve by the partial penetration weld, after all, it thinks that the overall fatigue life can improve.

• Journal of Korea Trade
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• v.24 no.8
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• pp.19-38
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• 2020

Purpose - The Korean government has been promoting the New Southern Policy (NSP) prior to the onset of the COVID-19 pandemic, which damage global value chain (GVC). The purpose of this paper is to emphasize that the NSP should be developed to provide tangible support in corporate GVC adjustment, away from diplomatic activities in order to offset GVC losses due to COVID-19 and expand export capabilities. Design/methodology - Two research methodologies are combined for this paper: A computational general equilibrium (CGE) model is used to estimate the impacts of the COVID-19 pandemic and NSP on Korea's exports, and the decomposition methodology (Wang, Wei and Zhu, 2013) to evaluate the stability of GVC. The conventional CGE model was modified to obtain an estimate for decomposition. The research methodology adopted in this study was attempted for the first time, and it can be widely used in future GVC research. Findings - Results found the effects of COVID-19 reduced Korea's total exports by 27% and GVC by more than 30%. In particular, VA in Korea's exports to the NSP region was found to have a huge impact in heavy industries and textiles, and its exports to Vietnam seemed to suffer the largest loss in GVC among ASEAN countries. If the NSP is implemented properly, it appears that it could offset much of the negative impacts of COVID-19, implying the importance of the effectiveness of the NSP. Originality/value - Many papers have assessed the NSP descriptively, and the GVC has been a topic for many publications. However, the impact of COVID-19 on Korea's GVC with the NSP countries has not been quantitatively studied. This paper emphasizes that the NSP should be pursued based on the results of quantitative analysis. In addition, the research methodology of this paper can be used for other GVC research with relevant modifications.

• Journal of Astronomy and Space Sciences
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• v.39 no.3
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• pp.117-126
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• 2022

The Ionospheric Anomaly Monitoring by Magnetometer And Plasma-probe (IAMMAP) is one of the scientific instruments for the Compact Advanced Satellite 500-3 (CAS 500-3) which is planned to be launched by Korean Space Launch Vehicle in 2024. The main scientific objective of IAMMAP is to understand the complicated correlation between the equatorial electro-jet (EEJ) and the equatorial ionization anomaly (EIA) which play important roles in the dynamics of the ionospheric plasma in the dayside equator region. IAMMAP consists of an impedance probe (IP) for precise plasma measurement and magnetometers for EEJ current estimation. The designated sun-synchronous orbit along the quasi-meridional plane makes the instrument suitable for studying the EIA and EEJ. The newly-devised IP is expected to obtain the electron density of the ionosphere with unprecedented precision by measuring the upper-hybrid frequency (f_UHR) of the ionospheric plasma, which is not affected by the satellite geometry, the spacecraft potential, or contamination unlike conventional Langmuir probes. A set of temperature-tolerant precision fluxgate magnetometers, called Adaptive In-phase MAGnetometer, is employed also for studying the complicated current system in the ionosphere and magnetosphere, which is particularly related with the EEJ caused by the potential difference along the zonal direction.

• Journal of Preventive Medicine and Public Health
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• v.36 no.4
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• pp.349-358
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• 2003

Objectives : Aseptic meningitis is a major cause of Korean childhood morbidity late spring and early summer. However, the nationwide incidences of the disease have not been reported. This study was conducted to evaluate the availability of National Health Insurance data (NHID) for the study of an epidemiological trend in the surveillance of aseptic meningitis in children. Methods : All the claims, under A87, A87.8, and A87.9 by ICD-10, among children below 15 years of age, to the National Health Insurance Corporation, between January and December 1998, were extracted. A survey of the medical record of 3,874 cases from 136 general hospitals was peformed. The availability of the NHID was evaluated by the three following methods: 1) The diagnostic accuracy (the positive Predictive value : proportion of the confirmed aseptic meningitis among the subjects registered as above disease-codes in NHID) was evaluated through a chart review, and according to age, gender, month and region of disease-occurrence. 2) The distribution of confirmed cases was compared with the distribution of total subjects from the NHID, for subjects in General hospitals, or the subjects surveyed. 3) The proportion of confirmed CSF test was confirmed, and the relating factor, which was the difference in CSF-test rate, analyzed. Results : Among 3,874 cases, CSF examinations were peformed on 1,845 (47.6%), and the CSF-test rates were different according to the medical utility (admission vs. OPD visit) and the severity of the symptoms and signs. The diagnostic accuracy for aseptic meningitis, and during the epidemic (May-Aug) and sporadic (Sept-Apr) periods, were 85.0 (1,568/1,845), 86.0 (1,239/l,440) and 81.2% (329/405), respectively. The distributions by age, sex, month or period (epidemic/sporadic) and region, in the confirmed cases, were similar to those in the NHID, in both the subjects at General hospitals and in those surveyed, to within ${\pm}7%$. Conclusions : In this paper, the NHID for the subjects registered with an aseptic meningitis disease-code might be available for an epidemiological study on the incidence-estimation of childhood aseptic meningitis, as the NHID could include both the probable and definite cases. On the basis of this result, further studies of time-series and secular trend analyses, using the NHID, will be peformed.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.838-850
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• 2012

In this paper, we propose a novel algorithm that generates multi-view images by using various image features obtained from the given stereoscopic images. In the proposed algorithm, we first create an intensity gradient saliency map from the given stereo images. And then we calculate a block-based optical flow that represents the relative movement(disparity) of each block with certain size between left and right images. And we also obtain the disparities of feature points that are extracted by SIFT(scale-invariant We then create a disparity saliency map by combining these extracted disparity features. Disparity saliency map is refined through the occlusion detection and removal of false disparities. Thirdly, we extract straight line segments in order to minimize the distortion of straight lines during the image warping. Finally, we generate multi-view images by grid mesh-based image warping algorithm. Extracted image features are used as constraints during grid mesh-based image warping. The experimental results show that the proposed algorithm performs better than the conventional DIBR algorithm in terms of visual quality.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.250-257
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• 2010

In this study, three different devices, Norland, Osteocore and Lunar were used to compare and analyze the measurement error by each bone density measurement device by classifying the physical characteristics into age, height and weight, the subject of total 300 sampling 100 persons for each device. Categorizing Lumbar region and Femoral neck as normal (T-score$\geqq$-1.0), osteopenia (-1.0>T-score>-2.5) and osteoporosis (T-score$\leqq$-2.5), the findings were observed as follows. Norland device showed the least measurement error in age and height, while Lunar showed the least in weight among the devices. And, the result of comparing the bone density measurement error based on the lumbar region showed that all of Lunar, Norland and Osteocore have the least variation of measurement error in osteopenia and the result of comparing based on the femoral neck showed that all of Lunar, Norland and Osteocore have the least variation of measurement error in osteoporosis. For each variable, the measurement error was observed to be vary upon the device. To solve this, standardized common Phantom should be used to compare and converge the measured value of each company and cross-calibration would be necessary when replacing the software.