• The KIPS Transactions:PartB
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• v.14B no.6
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• pp.431-436
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• 2007

Magnetic Resonance Imaging(MRI) has chemical shift phenomenon between fat and water, and the phenomenon has influence on structure enclosed by fat. Strong signals emitted from fat often generate false artefact, which reflects the importance of fat suppression techniques. There have been a number of researches on fat suppression techniques, but using fat suppression method alone in MRI can cause difficultproblems in diagnosis. This paper aims to study a fat suppression method by Chemical Shift Selective saturation(CHESS). This research describes the theoretical background and the experiment on water and fat phantom with MR instruments. In the experiment, CHESS pulse was designed by utilising Matlap program, and the pulse diagram was generated for the Pre-saturation process. The experiment using water and fat phantom was applied to C-spine, L-spine and Breast, and produced successful fat suppression results. This experiment has proved that the CHESSpulse fat suppression is a very helpful technique in diagnosing medical imaging. This method is a robust and useful technique for both clinical and basic investigators..(Experiment with Chungnam national university hospital G.E 1.5T MR)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.161-166
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• 2018

In this paper, we propose a method for the random selection of pooling operations for the regularization and reduction of cross validation in convolutional neural networks. The pooling operation in convolutional neural networks is used to reduce the size of the feature map and for its shift invariant properties. In the existing pooling method, one pooling operation is applied in each pooling layer. Because this method fixes the convolution network, the network suffers from overfitting, which means that it excessively fits the models to the training samples. In addition, to find the best combination of pooling operations to maximize the performance, cross validation must be performed. To solve these problems, we introduce the probability concept into the pooling layers. The proposed method does not select one pooling operation in each pooling layer. Instead, we randomly select one pooling operation among multiple pooling operations in each pooling region during training, and for testing purposes, we use probabilistic weighting to produce the expected output. The proposed method can be seen as a technique in which many networks are approximately averaged using a different pooling operation in each pooling region. Therefore, this method avoids the overfitting problem, as well as reducing the amount of cross validation. The experimental results show that the proposed method can achieve better generalization performance and reduce the need for cross validation.

• Smart Media Journal
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• v.2 no.4
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• pp.60-65
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• 2013

In this paper, we propose a high-resolution disparity map generation method using a low-resolution time-of-flight (TOF) depth camera and color camera. The TOF depth camera is efficient since it measures the range information of objects using the infra-red (IR) signal in real-time. It also quantizes the range information and provides the depth image. However, there are some problems of the TOF depth camera, such as noise and lens distortion. Moreover, the output resolution of the TOF depth camera is too small for 3D applications. Therefore, it is essential to not only reduce the noise and distortion but also enlarge the output resolution of the TOF depth image. Our proposed method generates a depth map for a color image using the TOF camera and the color camera simultaneously. We warp the depth value at each pixel to the color image position. The color image is segmented using the mean-shift segmentation method. We define a cost function that consists of color values and segmented color values. We apply a weighted average filter whose weighting factor is defined by the random walk probability using the defined cost function of the block. Experimental results show that the proposed method generates the depth map efficiently and we can reconstruct good virtual view images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.6C
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• pp.593-603
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• 2009

In this paper, we propose a new integrated computer vision system designed to track multiple human beings and extract their silhouette with an active stereo camera. The proposed system consists of three modules: detection, tracking and silhouette extraction. Detection was performed by camera ego-motion compensation and disparity segmentation. For tracking, we present an efficient mean shift based tracking method in which the tracking objects are characterized as disparity weighted color histograms. The silhouette was obtained by two-step segmentation. A trimap is estimated in advance and then this was effectively incorporated into the graph cut framework for fine segmentation. The proposed system was evaluated with respect to ground truth data and it was shown to detect and track multiple people very well and also produce high quality silhouettes. The proposed system can assist in gesture and gait recognition in field of Human-Robot Interaction (HRI).

• BMB Reports
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• v.43 no.11
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• pp.744-749
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• 2010

The aim of this work was to determine whether intrinsically bent DNA sites are present at, or close to, the mammalian replication origins oriGNAI3 and oriB in the Chinese hamster AMPD2 locus. Using an electrophoretic mobility shift assay and in silico analysis, we located four intrinsically bent DNA sites (b1 to b4) in a fragment that contains the oriGNAI3 and one site (b5) proximal to oriB. The helical parameters show that each bent DNA site is curved in a left-handed superhelical writhe. A 2D projection of 3D fragment trajectories revealed that oriGNAI3 is located in a relatively straight segment flanked by bent sites b1 and b2, which map in previously identified Scaffold/Matrix Attachment Region. Sites b3 and b4 are located approximately 2 kb downstream and force the fragment into a strong closed loop structure. The b5 site is also located in an S/MAR that is found just downstream of oriB.

• Journal of Microbiology
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• v.44 no.4
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• pp.375-382
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• 2006

From its initial colonization to causation of disease, Streptococcus pneumoniae has evolved strategies to cope with a number of stressful in vivo environmental conditions. In order to analyze a global view of this organism's response to heat shock, we established a 2-D electrophoresis proteome map of the S. pneumoniae D39 soluble proteins under in vitro culture conditions and performed the comparative proteome analysis to a 37 to $42^{\circ}C$ temperature up-shift in S. pneumoniae. When the temperature of an exponentially growing S. pneumoniae D39 culture was raised to $42^{\circ}C$, the expression level of 25 proteins showed changes when compared to the control. Among these 25 proteins, 12 were identified by MALDI-TOF and LC-coupled ESI MS/MS. The identified proteins were shown to be involved in the general stress response, energy metabolism, nucleotide biosynthesis pathways, and purine metabolism. These results provide clues for understanding the mechanism of adaptation to heat shock by S. pneumoniae and may facilitate the assessment of a possible role for these proteins in the physiology and pathogenesis of this pathogen.

• Journal of Broadcast Engineering
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• v.22 no.5
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• pp.608-617
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• 2017

Methods of contrast enhancement have problem such as side effect of over-enhancement with non-gaussian histogram distribution, tradeoff enhancement efficiency against brightness preserving. In order to enhance contrast at various histogram distribution, segmentation to region with gaussian distribution and then enhance contrast each region. First, we segment an image into several regions using GMM(Gaussian Mixture Model)fitting by that k-mean clustering and EM(Expectation-Maximization) in $L^*a^*b^*$ color space. As a result region segmentation, we get the region map and probability map. Then we apply local contrast enhancement algorithm that mean shift to minimum overlapping of each region and preserve brightness histogram equalization. Experiment result show that proposed region based contrast enhancement method compare to the conventional method as AMBE(AbsoluteMean Brightness Error) and AE(Average Entropy), brightness is maintained and represented detail information.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.115-121
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• 1990

The interaction between a calcium channel blocker nifedipine and atrial natriuretic peptide (ANP) was examined in normotensive and renal hypertensive rats. The infusion of either ANP or nifedipine produced a significant decrease in mean arterial pressure (MAP). The combined infusion of ANP with nifedipine resulted in a greater fall of MAP than did the infusion of each drug alone. ANP significantly increased urinary volume and excretion of sodium, while nifedipine was without effects. The diuretic/natriuretic effects of ANP were potentiated by the combined infusion with nifedipine. The vasodepressor and renal effects of ANP or nifedipine were qualitatively similar between the normotensive and hypertensive rats. Nifedipine caused an upward and leftward shift of the ANP dose-relaxation curve of the phenylephrine-precontracted thoracic aortic rings isolated from the normotensive rats , suggesting that the vasodilation sensitivity to ANP is increased in the presence of nifedipine. These results indicate that nifedipine enhances the vasodepressor effect of ANP, the likely mechanisms being attributable to a contraction of effective intravascular volume as a consequence of potentiated renal excretion and a greater peripheral vasodilation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.299-309
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• 1998

The national coordinate system is an essential component for a geographic/land information system, since it provides the spatial reference for expressing position information. The national mapping of Korea has been based on 3-different meridians on the Gauss-Schreiber projection in year 1910s, later this was changed to the Gauss-Kruger projection. Existing map coordinate systems maintaining the national land survey project on 1910s, have some structural shortcomings of unknown computational procedures and projection methods. In this paper, the problems of the map coordinates usage and of longitudes origin shift(10.405") and their solutions are investigated. Also, this study discusses the issues involved in choosing coordinate system for digital mapping and their applications as a basis for spatial data management. The foreign country's coordinate systems are reviewed and the elements to realize a new unified grid coordinate system is proposed. The Transverse Mercator projection with a central meridian of $127^\circ\;30'$, scale factor 0.9996, and GRS80 ellipsoid, is selected in Korean peninsula.sula.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.139-150
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• 1998

Recently in connection with the development of network technology, GIS researches shift their focuses to openGIS which enables to share heterogeneous geodata and geoprocessing resource under the environment of LAN and WAN. This study proposes an easy method to develope GUIs which enables openGIS in the intranet environment. In the developing stage of GUI, the most important thing is to develop effective windows programming technique and apply a internet linking technique to developed GUIs. This study shows an internet linking technique and a GUI developing method using OLE automation and ActiveX/COM standards. Using a case study of Taegu City Library, the study constructs a GIS database and develops its GUI which performs map overlaying, referencing attribute tables, drawing up of thematic map, buffer analysis, and statistical calculations. This study remains same further research areas of developing a new advanced technique for openGIS and its GUI using distributed object model of CORBA, Java language, and JDBC data accessing technique.