• The KIPS Transactions:PartD
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• v.8D no.4
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• pp.367-376
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• 2001

For the electronic map service by wireless, the existing map database cannot be used directly. This is because, the data volume of a map is too big to transfer by wireless and although the map is transferred successfully, the devices to display the map usually don’t have enough resources as the ones for desktop computers. It is also not acceptable to construct map database for the exclusive use of wireless service because of the vast cost. We propose new technique to generate a map for wireless service dynamically, from the existing map database. This technique includes the generalization method to reduce the map data volume and filtering method to guarantee that the data volume don’t exceed the limit of bandwidth. The generalization is performed in 3 steps :ㅁ step of merging the layers, a step of reducing the size of spatial objects, and a step of processing user interface. The filtering is performed by 2 module, counter and selector module. The counter module checks whether the data blume of generated map by generalization, exceeds the bandwidth limit. The selector module eliminates the excess objects and selects the rest, on the basis of distance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.219-221
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• 2022

In recent summer, as it is concentrated, even in mountainous areas, flooding and flooding cause casualties in pedestrian evacuation situations. To compensate for this, a system that detects the occurrence of flooding and allows pedestrians to evacuate safely is required. Therefore, in this paper, we propose a research on pedestrian path search based on the shortest distance algorithm using Map API. The pedestrian route search system outputs a map using the T Map API, selects nearby buildings as shelters, and stores data. A shelter close to the pedestrian's current location is selected, and the shortest route is output and the distance and time are provided. If there is a problem with the current route during evacuation, another shelter route is provided from the current location. Therefore, it is thought that the pedestrian route search evacuation system proposed in this paper will prevent accidents during evacuation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.435-444
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• 2012

Although the multi-scale map database should be constructed for the web map services and location-based services, much part of generation process is based on the manual editing. In this study, the map generalization methodology for automatic construction of multi-scale database from the primary data is proposed. Moreover, the generalization methodology is applied to the real map data and the prototype of multi-scale map dataset is generated. Among the generalization operators, selection/elimination, simplification and amalgamation/aggregation is applied in organized manner. The algorithm and parameters for generalization is determined experimentally considering T$\ddot{o}$pfer's radical law, minimum drawable object of map and visual aspect. The target scale level is five(1:1,000, 1:5,000, 1:25,000, 1:100,000, 1:500,000) and for the target data, new address data and digital topographic map is used.

• Biomedical Science Letters
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• v.11 no.1
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• pp.31-36
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• 2005

To evaluate the magnetic resonance imaging and electron microscopic findings of the hyperacute stage of cerebral fat embolism in cats and the time needed for the development of vasogenic edema. Magnetic resonance imaging was performed at 30 minutes (group 1, n=9) and at 30 minutes and 1, 2, 4, and 6 hours after embolization with triolein (group 2, n= 10). As a control for group 2, the same acquisition was obtained after embolization with polyvinyl alcohol particles (group 3, n=5). Electron microscopic examination was done in all cats. In group 1, the lesions were iso- or slightly hyperintense on T2-weighted (T2W) and diffusion-weighted (DWIs) images, hypointense on the apparent diffusion coefficient (ADC) map image, and markedly enhanced on the gadolinium-enhanced T1-weighted images (Gd-T1WIs). In group 2 at 30 minutes, the lesions were similar to those in group 1. Thereafter, the lesions became more hyperintense on T2WIs and DWIs and more hypoinfense on the ADC map image. In group 3, the lesions showed mild hyperintensity on T2WIs at 6 hours but hypointensity on the ADC map image from 30 minutes, with a tendency toward a greater decrease over time. Electron microscopic findings revealed discontinuity of the capillary endothelial wall, perivascular and interstitial edema, and swelling of glial and neuronal cells in groups 1 and 2. The lesions were hyperintense on T2WIs and DWIs, hypointense on the ADC map image, and enhanced on Gd-T1WIs. On electron microscopy, the lesions showed cytotoxic and vasogenic edema with disruption of the blood-brain barrier.

• Investigative Magnetic Resonance Imaging
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• v.7 no.2
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• pp.116-123
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• 2003

Purpose : The present study was undertaken to evaluate the usefulness of cerebral diffusion (DWI) and perfusion MR imaging (PWI) in rabbit models with hyperacute cerebral ischemic infarction. Materials and Methods : Experimental cerebral infarction were induced by direct injection of mixture of Histoacryl glue, lipiodol, and tungsten powder into the internal cerebral artery of 6 New-Zealand white rabbits, and they underwent conventional T1 and T2 weighted MR imaging, DWI, and PWI within 1 hour after the occlusion of internal cerebral artery. The PWI scan for each rabbit was obtained at the level of lateral ventricle and 1cm cranial to the basal ganglia. By postprocessing using special imaging software, perfusion images including cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps were obtained. The detection of infarcted lesion were evaluated on both perfusion maps and DWI. MTT difference time were measured in the perfusion defect lesion and symmetric contralateral normal cerebral hemisphere. Results : In all rabbits, there was no abnormal signal intensity on T2WI. But on DWI, abnormal high signal intensity, suggesting cerebral infarction, were detected in all rabbits. PWI (rCBV, CBF and MTT map) also showed perfusion defect in all rabbits. In four rabbits, the calculated square of perfusion defect in MTT map is larger than that of CBF map and in two rabbits, the calculated size of perfusion defect in MTT map and CBF map is same. Any rabbits do not show larger perfusion defect on CBF map than MTT map. In comparison between CBF map and DWI, 3 rabbits show larger square of lesion on CBF map than on DWI. The others shows same square of lesion on both technique. The size of lesion shown in 6 MTT map were larger than DWI. In three cases, the size of lesion shown in CBF map is equal to DWI. But these were smaller than MTT map. The calculated square of lesion in CBF map, equal to that of DWI and smaller than MTT map was three. And in one case, the calculated square of perfusion defect in MTT map was largest, and that of DWI was smallest. Conclusion : DWI and PWI may be useful in diagnosing hyperacute cerebral ischemic infarction and in e-valuating the cerebral hemodynamics in the rabbits.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.3
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• pp.229-238
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• 2013

Development of methodologies to generate the small scale map from the large scale map using map generalization has huge importance in management of the digital topographic map, such as producing and updating maps. In this study, the selection methodology of map generalization for the road network data in digital topographic map is investigated and evaluated. The existing maps with 1:5,000 and 1:25,000 scales are compared and the criteria for selection of the road network data, which are the number of objects and the relative importance of road network, are analyzed by using the T$\ddot{o}$pfer's radical law and Logit model. The selection model derived from the analysis result is applied to the test data, and the road network data of 1:18,000 and 1:72,000 scales from the digital topographic map of 1:5,000 scale are generated. The generalized results showed that the road objects with relatively high importance are selected appropriately according to the target scale levels after the qualitative and quantitative evaluations.

• Investigative Magnetic Resonance Imaging
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• v.23 no.4
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• pp.328-340
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• 2019

Purpose: To generate phase images with free of motion-induced artifact and susceptibility-induced distortion using 3D radial ultrashort TE (UTE) MRI. Materials and Methods: The field map was theoretically derived by solving Laplace's equation with appropriate boundary conditions, and used to simulate the image distortion in conventional spin-warp MRI. Manufacturer's 3D radial imaging sequence was modified to acquire maximum number of radial spokes in a given time, by removing the spoiler gradient and sampling during both rampup and rampdown gradient. Spoke direction randomly jumps so that a readout gradient acts as a spoiling gradient for the previous spoke. The custom raw data was reconstructed using a homemade image reconstruction software, which is programmed using Python language. The method was applied to a phantom and in-vivo human brain and abdomen. The performance of UTE was compared with 3D GRE for phase mapping. Local phase mapping was compared with T₂* mapping using UTE. Results: The phase map using UTE mimics true field-map, which was theoretically calculated, while that using 3D GRE revealed both motion-induced artifact and geometric distortion. Motion-free imaging is particularly crucial for application of phase mapping for abdomen MRI, which typically requires multiple breathold acquisitions. The air pockets, which are caught within the digestive pathway, induce spatially varying and large background field. T₂* map, that was calculated using UTE data, suffers from non-uniform T₂* value due to this background field, while does not appear in the local phase map of UTE data. Conclusion: Phase map generated using UTE mimicked the true field map even when non-zero susceptibility objects were present. Phase map generated by 3D GRE did not accurately mimic the true field map when non-zero susceptibility objects were present due to the significant field distortion as theoretically calculated. Nonetheless, UTE allows for phase maps to be free of susceptibility-induced distortion without the use of any post-processing protocols.

• Biomedical Science Letters
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• v.2 no.2
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• pp.175-185
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• 1996

The mitogen-activated protein(MAP) kinase signal transduction pathway represents an important mechanism by which mitogen, such as serum and PMA, regulate cell proliferation and differentiation. Target substrates of the MAP kinase are located within several compartments containing plasma membranes and nucleus. We now report that serum addition induces proliferation of the P388 murine leukemia cell, but PMA does not, while both serum and PMA treatment cause translocation of the MAP kinase, mainly p42$^{mapk}$ isoform, from cytosol into the nucleus, which was monitored by immunoblot analysis using polyclonal anti-ERK1 antibodies. We investigated whether the MAP kinase was capable of phosphorylating c-Jun protein and GST-fusion proteins, the P562$^{kk}$N-terminal peptides (1-77 or 1-123 domain) of the T cell tyrosine kinase, using the partially purified MAP kinase by SP-sephadex C-50, phenyl superose and Mono Q column chromatography. We found that the partially purified MAP kinase was able to phosphorylate c-Jun protein and the GST-fusion protein expressed using E.coli DH5$\alpha$ which is transformed with pGEX-3Xb plasmid vector carrying of p562$^{kk}$N-terminal peptide-encoding DNA. These results imply that tyrosine kinase receptor/Ras/Raf/MAP kinase pathway is a major mechanism for mitogen-induced cell proliferation in P388 murine leukemia cell and that the various MAP kinase isoforms may have their own target substrates located in distinct subcellular compartments.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.49-54
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• 2003

As of date, the cadastral information which is the utility to be computerized have not been identical with local autonomous entities and relational groups each other and updated real-time, therefore the relation group or the academic circles carried out in many researches on a cadastral map matching, but the cadastral maps have not been even occurred the expansion and contraction so that the theory arrangement doesn't seem simple as to a cadastral map matching. As being take such reality into consideration, We have to be based on $\boxDr$construction ministry of the rules for continuous map$\boxUl$ for a continuous cadastral map with using PBLIS data; so the operators use Autodesk Map 5 which added applications and match the neat line by the identical scale, the different scale, the district boundary and the origin according to the judgement myself We have the purpose to minimize the problem as analyzing the accuracy between the parcel coordinates If the matched map and ones of moved map.

• The Korean Journal of Applied Statistics
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• v.16 no.2
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• pp.321-333
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• 2003

Self-organizing map (SOM), a unsupervised learning neural network, has been developed by T. Kohonen since 1980's. Main application areas were pattern recognition and text retrieval. Because of that, it has not been spread to statisticians until late. Recently, SOM's are frequently drawn in data mining fields. Kohonen's SOM, however, needs improvements to become a statistician's standard tool. First, there should be a good guideline as for the size of map. Second, an enhanced visualization mode is wanted. In this study, principal components self-organizing map (PC-SOM), a modification of Kohonen's SOM, is proposed to meet such needs. PC-SOM performs one-dimensional SOM during the first stage to decompose input units into node weights and residuals. At the second stage, another one-dimensional SOM is applied to the residuals of the first stage. Finally, by putting together two stages, one obtains two-dimensional SOM. Such procedure can be easily expanded to construct three or more dimensional maps. The number of grid lines along the second axis is determined automatically, once that of the first axis is given by the data analyst. Furthermore, PC-SOM provides easily interpretable map axes. Such merits of PC-SOM are demonstrated with well-known Fisher's iris data and a simulated data set.