• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.218-224
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• 2004

We compared rest perfusion PET with redistribution perfusion SPECT to investigate the concordant rate between PET and SPECT images and analyze the discordant pattern. Materials and Methods: Rest N-13 ammonia and F-18 FDG PET were performed on 18 patients with old myocardial infarction and left ventricular dysfunction whose dipyridamole - 4hr redistribution TI-201 SPECT showed one or more severe fixed defects. Regional perfusion and metabolism were evaluated visually and quantitatively with 5-segment myocardial model. Results: There were high concordant rate in uptake pattern (80/90 segments, 88.9%) and high correlation coefficient on quantitative analysis (R=0.81, p<0.001) between redistribution TI-201 SPECT and N-13 ammonia PET images. Nine of 18 patients had SPECT-PET concordant pattern (Group I). Ten segments (9 in inferior wall, 1 in apex) from the remaining 9 patients showed SPECT-PET discordant pattern with abnormal TI-201 defect and near normal N-13 ammonia uptake (Group II). The diastolic and systolic left ventricular dimensions were significantly increased in Group II compared to those of Group I. When attenuation uncorrected N-13 ammonia PET images were reconstructed in Group II, it resulted in PET images with severe inferior wall defects nearly identical to those seen in redistribution TI-201 SPECT images. Conclusion: Redistribution TI-201 SPECT images showed high concordant rate and correlation with rest N-13 ammonia PET images. Most of discordant segments had fixed thallium defects in inferior wall with nearly normal N-13 ammonia uptake, which may result from severe left ventricular dilatation and attenuation by the left hemidiaphragm and cardiac blood pool.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.2
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• pp.69-77
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• 2022

The 3D spatial model is an analysis framework for solving urban problems and is used in various fields such as urban planning, environment, land and housing management, and disaster simulation. The utilization of drones that can capture 3D images in a short time at a low cost is increasing for the construction of 3D spatial model. In terms of building a virtual city and utilizing simulation modules, high location accuracy of aerial survey and precision of 3D spatial model function as important factors, so a method to increase the accuracy has been proposed. This study analyzed location accuracy of aerial survey and precision of 3D spatial model by each condition of aerial survey for urban areas where buildings are densely located. We selected Daerim 2-dong, Yeongdeungpo-gu, Seoul as a target area and applied shooting angle, shooting altitude, and overlap rate as conditions for the aerial survey. In this study, we calculated the location accuracy of aerial survey by analyzing the difference between an actual survey value of CPs and a predicted value of 3D spatial Model. Also, We calculated the precision of 3D spatial Model by analyzing the difference between the position of Point cloud and the 3D spatial Model (3D Mesh). As a result of this study, the location accuracy tended to be high at a relatively high rate of overlap, but the higher the rate of overlap, the lower the precision of 3D spatial model and the higher the shooting angle, the higher precision. Also, there was no significant relationship with precision. In terms of baseline-height ratio, the precision tended to be improved as the baseline-height ratio increased.

• The Korean Journal of Gastroenterology
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• v.72 no.6
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• pp.295-303
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• 2018

Background/Aims: The primary aims of this study were to evaluate the content quality of YouTube videos on exercises to help relieve constipation and to assess whether the video source, exercise types, and popularity affected their quality. Methods: Eight gastroenterologists independently evaluated the exercises presented in the constipation YouTube videos for seven items: image quality, usefulness in relieving constipation (quality 1), usefulness for general physical health (quality 2), difficulty in following, activity intensity, fun, and overall quality. Raters were asked open-ended questions to evaluate the strengths and weaknesses of the videos. Five-point ordinal scales were used to score each item aforementioned, with the exception of image quality and overall quality that used a six-point Likert scale. Results: The 20 videos had a mean length of 268 seconds and a mean viewership of 32,694. The most common video source was commercial (n=10), and the most common type of physical activity was yoga (n=11). The median values of image quality, quality 1, quality 2, difficulty in following, activity intensity, fun, and overall quality were 3, 2, 2, 2, 2, 2, and 2, respectively. Yoga videos had significantly higher median quality 1 values (3) compared with massage videos (2, adjusted p=0.006) and 'others' videos (2, adjusted p<0.001). A lack of medical evidence was the most common answer to open-ended questions about the weaknesses of each video. Conclusions: Overall, YouTube exercise videos presented a low-quality content. This study highlights the need for evidence-based comprehensive educational videos addressing exercises for treating constipation.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.352-357
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• 2013

This study estimates the classification criteria which distinguishes the types of omega-3 health functional foods, fish oils and fish oil usages through $^{13}C$-NMR spectra and fatty acids contents analysis. The major fatty acids of omega-3, eicosapentaenoic acid (EPA, $C_{20:5}$) and docosahexaenoic acid (DHA, $C_{22:6}$) are being analyzed. 10 ethyl ester (EE) forms and 10 triglyceride (TG) forms are the most common types of fish oils for 20 omega-3 products. Gas chromatography (GC) analysis generally shows the matching EPA and DHA contents of the products listed on the notation. But EE form contents of EPA and DHA are higher and are more varied than the TG form. Most of the samples of EPA/DHA ratio show different content ratios of indicated on the products when comparing with standards. The $^{13}C$-NMR analysis of EPA and DHA on sn-1,3 and sn-2 carbonyl peak position with fish oil triglycerides display whether the reconstituted triglycerides (rTG) are being confirmed or not. As a result of the 9 TG form, the 10 TG products showed similar values: EPA sn-1, 3; 13.46~15.66, sn-2; 3.00~4.52, DHA sn-1, 3; 2.43~4.40, sn-2; 3.84~6.36. But one product showed lower contents (EPA: sn-1, 3; 5.88, sn-2; 2.86, DHA sn-1, 3; 2.29, sn-2; 5.95) of EPA, thus it can be considered a different type of oil and only matched six products according to the label. This study is intended to provide basic materials which identify the status for the types and quality of omega-3 fish oil products according to fatty acids profiles and the $^{13}C$-NMR spectrum confirmed the location specificity of EPA and DHA.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.8
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• pp.367-376
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• 2007

In this paper, we introduce an application-specific and adaptive power management technique for portable systems that support dynamic voltage scaling (DVS). We exploit both the idle time of multitasking systems running soft real-time tasks as well as memory- or CPU-bound code regions. Detailed power and execution time profiles guide an adaptive power manager (APM) that is linked to the operating system. A post-pass optimizer marks candidate regions for DVS by inserting calls to the APM. At runtime, the APM monitors the CPU's performance counters to dynamically determine the affinity of the each marked region. for each region, the APM computes the optimal voltage and frequency setting in terms of energy consumption and switches the CPU to that setting during the execution of the region. Idle time is exploited by monitoring system idle time and switching to the energy-wise most economical setting without prolonging execution. We show that our method is most effective for periodic workloads such as video or audio decoding. We have implemented our method in a multitasking operating system (Microsoft Windows CE) running on an Intel XScale-processor. We achieved up to 9% of total system power savings over the standard power management policy that puts the CPU in a low Power mode during idle periods.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.17 no.2
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• pp.48-54
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• 2017

Purpose: Fukuyama congenital muscular dystrophy (FCMD) is a rare, autosomal-recessive disorder characterized by early-onset hypotonia associated with brain malformations in dystroglycanopathy. Although the wide spectrum of congenital muscular dystrophies causes difficulty in diagnosis, correlating the genotype with the clinical phenotype can help diagnose FCMD. Here, we evaluated the correlation of targeted molecular genetic analysis of FKTN gene mutation with the FCMD phenotype. Methods: This study was conducted retrospectively with 9 subjects. Inclusion criteria included clinical symptoms characterized by early-onset hypotonia with magnetic resonance imaging (MRI) featuring brain malformations. FKTN gene-alteration analysis was performed using various FKTN gene-analysis methods, including sequencing. Results: Among the 9 subjects studied, 4 (44.4%) were male and 5 (55.6%) were female. The median age of onset of the first symptom was 3.1 months. The first symptom was a delayed milestone in 6 cases (66.7%). All 9 subjects (100%) presented with early-onset hypotonia and global delayed development. All subjects presented with cortical malformation in their brain MRIs. Of the 9 subjects, 6 subjects had previously undergone muscle biopsy and 4 cases (4/6; 66.7%) showed dystrophic or myopathic features. Pathogenic mutations causing FCMD were identified in 3 cases. Conclusions: In this study, all 3 subjects with FKTN mutations showed important MRI findings (pachygyria and cerebellar dysplasia). These data suggest that patients with characteristic phenotypes who show pachygyria and cerebellar abnormalities in brain MRIs may have a high probability of being diagnosed with FCMD.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.105-110
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• 2010

Purpose: Three phase bone scan was considered sensitive in Patients with Reflex Symphathetic Dystrophy Syndrome (RSDS). Generally, three phase bone scan in the RSDS patients shows increased uptake of one side extremity joint. But three phase bone scan has been performed with flow, blood pool and delayed scan. We performed blood pool half body scan in order to investigate its usefulness. Materials and Methods: From October 2007 to September 2009, three phase bone scan (flow, blood pool, half body blood pool, delayed) was performed after injection of 750 MBq of $^{99m}Tc$-DPD in diagnosed patients with RSDS (M:F=8:7, R:L=9:6). For quantitative analysis, we obtained the count ratios of bilateral hands by drawing a region of interest (ROI) in the three phase images and compared with the count ratios of shoulders in half body blood pool and delayed images. Results: In flow images, right/left ratios were $1.09{\pm}0.53$. In blood pool images, right/left ratios were $1.13{\pm}0.47$ (hand), $1.08{\pm}0.26$ (shoulder). In delayed images, right/left ratios were $1.24{\pm}0.75$ (hand), $1.11{\pm}0.31$ (shoulder). As a result, Log of right/left counts of the others and that of shoulder blood pool image were correlated well with statistical significance (Spearman's R, p<0.005 SPSS for windows ver.12.0). Conclusion: Half body blood pool scan may be helpful in the diagnosis of patients with RSDS. Moreover, Half body blood pool scan reduced false negative and false positive rates. In order to improve agreement on interpretation of RSDS, Blood pool half body scan should be established as common criteria.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.98-105
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• 2013

This paper presents a finite-difference time-domain(FDTD) simulation and a data processing technique for radar sensing of the internal structure of a wall using an ultra-wide band antenna. We first designed an ultra-wide band anti-podal vivaldi antenna with a frequency range of 0.3~7 GHz which is chosen to be relatively low after considering the characteristics of wave attenuation, wall penetration, and range resolution. In this study the two-dimensional FDTD technique was used to simulate a wall-penetration-radar experiment under practical conditions. The next, the measured radiation pattern of the practical antenna is considered as an equivalent source in the FDTD simulation, and the reflection data of a concrete wall and targets are obtained by using the simulation. Then, a data processing technique has been applied to the FDTD reflection data to get a radar image for remote sensing of the internal structure of the wall. We compared the two different source excitations in the FDTD simulation; (1) commonly-used isotropic point sources and (2) polynomial curve fitting sources of the measured radiation pattern. As a result, when we apply the measured antenna pattern into the FDTD simulation, we could obtain about 2.5 dB higher signal to noise level than using a plane wave incidence with isotropic sources.

• Korean Journal of Remote Sensing
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• v.28 no.4
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• pp.409-420
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• 2012

Since the Industrial Revolution, CO2 levels have been increasing with climate change. In this study, Analyze time-series changes in snow cover quantitatively and predict the vanishing point of snow cover statistically using remote sensing. The study area is Mt. Kilimanjaro, Tanzania. 23 image data of Landsat-5 TM and Landsat-7 ETM+, spanning the 27 years from June 1984 to July 2011, were acquired. For this study, first, atmospheric correction was performed on each image using the COST atmospheric correction model. Second, the snow cover area was extracted using the NDSI (Normalized Difference Snow Index) algorithm. Third, the minimum height of snow cover was determined using SRTM DEM. Finally, the vanishing point of snow cover was predicted using the trend line of a linear function. Analysis was divided using a total of 23 images and 17 images during the dry season. Results show that snow cover area decreased by approximately $6.47km^2$ from $9.01km^2$ to $2.54km^2$, equivalent to a 73% reduction. The minimum height of snow cover increased by approximately 290 m, from 4,603 m to 4,893 m. Using the trend line result shows that the snow cover area decreased by approximately $0.342km^2$ in the dry season and $0.421km^2$ overall each year. In contrast, the annual increase in the minimum height of snow cover was approximately 9.848 m in the dry season and 11.251 m overall. Based on this analysis of vanishing point, there will be no snow cover 2020 at 95% confidence interval. This study can be used to monitor global climate change by providing the change in snow cover area and reference data when studying this area or similar areas in future research.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.629-633
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• 2008

Purpose : This study was designed to investigate normal domestic values for the diameter of the left main coronary artery (LCA), the left anterior descending coronary artery (LAD) and the right coronary artery (RCA). These data are necessary to define dilatation of coronary arteries in Kawasaki disease cases. Methods : Study subjects were 43 normal healthy children whose ages ranged from 3 months to 6 years. They children visited Konkuk University hospital for echocardiograph examination between March 2005 and November 2007. Measurements of coronary arterial diameters at each branch were done by off-line analyses of recorded images. Simple regression analysis of each the measurements were performed using the body size (body surface area, etc.) as the independent variable. Results : Body surface area was significantly related to the diameters of LCA ($r^2=0.20$, P=0.0038), of LAD ($r^2=0.41$, P<0.0001), and of RCA ($r^2=0.30$, P=0.0002). In the regression model, the estimates of the y-intercept were 1.703, 1.058, and 1.007; the estimates of the regression coefficient were 0.971, 1.175, and 1.177; and the estimates of the standard deviation were 0.315, 0.221, and 0.282 with respect to the three coronary arteries. Conclusion : A the linear regression model of the diameters of three coronary arteries adjusted for body surface area was produced. With these results, the Z-score calculation of the diameter of three coronary arteries, based on normal domestic data, will be possible.