• Investigative Magnetic Resonance Imaging
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• v.22 no.1
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• pp.37-49
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• 2018

Purpose: The effect of global inhomogeneity on quantitative susceptibility mapping (QSM) was investigated. A technique referred to as Simultaneous Unwrapping Phase with Error Recovery from inhomogeneity (SUPER) is suggested as a preprocessing to QSM to remove global field inhomogeneity-induced phase by polynomial fitting. Materials and Methods: The effect of global inhomogeneity on QSM was investigated by numerical simulations. Three types of global inhomogeneity were added to the tissue susceptibility phase, and the root mean square error (RMSE) in the susceptibility map was evaluated. In-vivo QSM imaging with volunteers was carried out for 3.0T and 7.0T MRI systems to demonstrate the efficacy of the proposed method. Results: The SUPER technique removed harmonic and non-harmonic global phases. Previously only the harmonic phase was removed by the background phase removal method. The global phase contained a non-harmonic phase due to various experimental and physiological causes, which degraded a susceptibility map. The RMSE in the susceptibility map increased under the influence of global inhomogeneity; while the error was consistent, irrespective of the global inhomogeneity, if the inhomogeneity was corrected by the SUPER technique. In-vivo QSM imaging with volunteers at 3.0T and 7.0T MRI systems showed better definition in small vascular structures and reduced fluctuation and non-uniformity in the frontal lobes, where field inhomogeneity was more severe. Conclusion: Correcting global inhomogeneity using the SUPER technique is an effective way to obtain an accurate susceptibility map on QSM method. Since the susceptibility variations are small quantities in the brain tissue, correction of the inhomogeneity is an essential element for obtaining an accurate QSM.

• Korean Journal of Cognitive Science
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• v.14 no.3
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• pp.13-21
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• 2003

This study presents a design of Teachable Agent(TA) and its theoretical background. TA is an intelligent agent to which students as tutors teach, pose questions, and provide feedbacks using a concept map. TA consists of four independent Modules, Teach Module, Q&A Module, Test Module, and Resource Module. In Teach Module, students teach TA by constructing concept map. In Q&A Module, both students and TA ask questions and answer questions each other through an interactive window. To assess TA's knowledge and provide feedback to students, Test Module consists of a set of predetermined questions which TA should pass. From Resource Module, students can search and look up important information to teach, ask questions, and provide feedbacks whenever they want. It is expected that TA should provide student tutors with an active role in learning and positive attitude toward the subject matter by enhancing their cognition as well as motivation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.11
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• pp.918-926
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• 2012

In 3D video transmission, a depth map being used for depth image based rendering (DIBR) is generally compressed by reducing resolution for coding efficiency. Errors in resolution reduction are recovered by an appropriate up-sampling method after decoding. However, most previous works only focus on up-sampling techniques to reduce errors. In this paper, we propose a novel down-sampling technique of depth map that applies different down-sampling rates on moving objects and background in order to enhance human perceptual quality. Experimental results demonstrate that the proposed scheme provides both higher visual quality and peak signal-to-noise ratio (PSNR). Also, our method is compatible with other up-sampling techniques.

• IMMUNE NETWORK
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• v.10 no.5
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• pp.145-152
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• 2010

Background: The flowers of Inula japonica (Inulae Flos) have long been used in traditional medicine for the treatment of inflammatory diseases. In the present study, we investigated the anti-inflammatory properties of Inulae Flos Extract (IFE). Methods: The anti-inflammatory effects of IFE against nitric oxide (NO), $PGE_2$, TNF-${\alpha}$, and IL-6 release, as well as NF-${\kappa}B$ and MAP kinase activation were evaluated in RAW 264.7 cells. Results: IFE inhibited the production of NO and the expression of inducible nitric oxide synthase (iNOS) in LPS-stimulated RAW264.7 cells. In addition, IFE reduced the release of pro-inflammatory cytokines, such as TNF-${\alpha}$ and IL-6. Furthermore, IFE inhibited the NF-${\kappa}B$ activation induced by LPS, which was associated with the abrogation of $I{\kappa}B-{\alpha}$ degradation and subsequent decreases in nuclear p65 and p50 levels. Moreover, the phosphorylation of ERK, JNK, and p38 MAP kinases in LPS-stimulated RAW 264.7 cells was suppressed by IFE in a dose-dependent manner. Conclusion: These results suggest that the anti-inflammation activities of IFE might be attributed to the inhibition of NO, iNOS and cytokine expression through the down-regulation of NF-${\kappa}B$ activation via suppression of $I{\kappa}B{\alpha}$ and MAP kinase phosphorylation in macrophages.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.44-53
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• 2011

In this paper, we propose a 3D conversion algorithm of 2D video using depth layer partition method. In the proposed algorithm, we first set frame groups using cut detection algorithm. Each divided frame groups will reduce the possibility of error propagation in the process of motion estimation. Depth image generation is the core technique in 2D/3D conversion algorithm. Therefore, we use two depth map generation algorithms. In the first, segmentation and motion information are used, and in the other, edge directional histogram is used. After applying depth layer partition algorithm which separates objects(foreground) and the background from the original image, the extracted two depth maps are properly merged. Through experiments, we verify that the proposed algorithm generates reliable depth map and good conversion results.

• Journal of architectural history
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• v.9 no.1 s.22
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• pp.27-46
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• 2000

This study aims at examining the background and development process of Masan city after Koryo Dynasty, making a reconstructive map of Original Masan using the first registration maps made in 1912 and analyzing the urban structure of the Original Masan area. The origin of Masan city went back to Koryo dynasty. Around 1040 Koryo government placed an official shipping facility in Masan to transport the taxed grain to the capital city. After that Masan became an important port covering the southern part of KyungSang-Do. And the urbanization of the Original Masan began to bud after a shipping facility was again established by the Chosun Dynasty in 1760 and strengthened in the 19th century after the social standing system was broken and many peasants moved to cities as daily workers. In 1899 Masan was forced to be opened to foreign powers and they placed an international settlement distanced from the area(Original Masan). After this many Japanese advanced to the international settlement and further to the area. The advancement of Japanese brought a critical change in the urban structure of the area. Land was owned by Japanese and many modern sysytems were introduced such as modern buildings, new roads, railroad and modern factories. According to the reconstructive map of the area, 80.5% of land lots are less than $200m^2$ showing the size of each land lot is comparatively small. And Japanese occupied 31.5% of the land in the area. Their land was located on the stratigic points near the port and the center of commerce. The ratio of the road area to the whole land was around 14%, not so low for urban areas in that time. The reconstructive map reveals the exact coastline of the year 1912 erased now due to filling the sea and extending the land, Present Masan city has been developed having the Original Masan as its nucleus. The area has been always the center of urban activities for Masan city. Making an exact reconstructive map for the area and analyzing the urban structure of the area in 1912 is a very important work to understand Masan city wholy.

• Journal of the Korean Geographical Society
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• v.49 no.4
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• pp.585-600
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• 2014

The purpose of this study is to consider the influence of the French Royal Academy of Science on the European mapping of China in the eighteenth century. For this, the historical background of French Jesuits mission of mathematicians sent to China by Louis XIV in 1685 was examined. It was found that making astronomical observations for the determination of Chinese geographic coordinates was one important reason of the French Jesuit mission. Secondly, Cassini instructed the longitude determination method to the missionaries and they reported their survey results to the Academy as correspondence member. Thirdly, the cartographic materials they accumulated in the first state were not sufficient to change the map of China. But after 1700, the map of China was broken with the Ptolemaic tradition and the longitude of Peking was moved westward about $20^{\circ}$. This reduced the width of China. Fourthly, the French Jesuit contributed to the making of Huangyu quanlan tu. The manuscipt was sent to France and it was published in d'Anvill's atlas. And his map was used as a standard map of China for more than 100 years.

• Tuberculosis and Respiratory Diseases
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• v.78 no.2
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• pp.85-91
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• 2015

Background: In sepsis patients, target mean arterial pressures (MAPs) greater than 65 mm Hg are recommended. However, there is no such recommendation for patients receiving mechanical ventilation. We aimed to evaluate the influence of MAP over the first 24 hours after intensive care unit (ICU) admission on the mortality rate at 60 days post-admission in patients showing acute hypoxemic respiratory failure under mechanical ventilation. Methods: This prospective, multicenter study included 22 ICUs and compared the mortality and clinical outcomes in patients showing acute hypoxemic respiratory failure with high (75-90 mm Hg) and low (65-74.9 mm Hg) MAPs over the first 24 hours of admission to the ICU. Results: Of the 844 patients with acute hypoxemic respiratory failure, 338 had a sustained MAP of 65-90 mm Hg over the first 24 hours of admission to the ICU. At 60 days, the mortality rates in the low (26.2%) and high (24.5%) MAP groups were not significantly different. The ICU days, hospital days, and 60-day mortality rate did not differ between the groups. Conclusion: In the first 24 hours of ICU admission, MAP range between 65 and 90 mm Hg in patients with acute hypoxemic respiratory failure under mechanical ventilation may not cause significantly differences in 60-day mortality.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.3
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• pp.143-149
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• 2018

Background: We evaluated the changes in mean arterial pressure (MAP) and heart rate (HR), and the anesthetic and hemostatic effects, after injection of 2% lidocaine containing various concentrations of epinephrine in rats and mice to determine the appropriate concentration of epinephrine in various anesthetic mixtures. Methods: Rats and mice were randomly allocated to experimental groups: 2% lidocaine without epinephrine (L0), 2% lidocaine with epinephrine 1:200,000 (L200), 1:100,000 (L100), and 1:80,000 (L80). Changes in MAP and HR after administration of the anesthetic mixture were evaluated using a physiological recording system in rats. Onset and duration of local anesthesia was evaluated by pricking the hind paw of mice. A spectrophotometric hemoglobin assay was used to quantify the hemostatic effect. Results: MAP increased in response to epinephrine in a dose-dependent manner; it was significantly higher in the L80 group than in the L0 group at 5 min post-administration. The HR was relatively lower in the L0 group than in the L80 group. The time required for onset of action was < 1 min in all evaluation groups. The duration of action and hemostatic effect of the local anesthetic were significantly better in the L200, L100, and L80 groups than in the L0 group. Conclusion: L200 demonstrated relatively stable MAP and HR values with satisfactory efficacy and hemostatic effect. L200 might be a better local anesthetic for dental patients in terms of anesthetic efficacy and safety.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.168-177
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• 2015

BACKGROUND: In recent year, there has been great concern regarding agricultural land uses and their importance for the conservation of biodiversity. Rice fields are managed unique wetland for wildlife, especially waterbirds. A comprehensive monitoring of the waterbird assemblage to understand patterning changes was attempted for rice ecosystem in South Korea. This rice ecosystem has been recognized as one of the most important for waterbirds conservation. METHODS AND RESULTS: Biweekly monitoring was implemented for the 4 years from April 2009 to March 2010, from April 2011 to March 2014. 32 species of waterbirds were observed. Self-organizing map (SOM) and random forest were applied to the waterbirds dataset to identify the characteristics in waterbirds distribution. SOM and random forest analysis clearly classified into four clusters and extract ecological information from waterbird dataset. Waterbird assemblages represented strong seasonality and habitat use according to waterbird group such as shorebirds, herons and waterfowl. CONCLUSION: Our results showed that the combination of SOM and random forest analysis could be useful for ecosystem assessment and management. Furthermore, we strongly suggested that a strict management strategy for the rice fields to conserve the waterbirds. The strategy could be seasonally and species specific.