• Journal of Korean Society for Geospatial Information Science
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• v.6 no.1 s.11
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• pp.65-74
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• 1998

The acquisition and analysis system of accurate geometrical digital data is very important in side of maintaining the traditional culture for the preservation of cultural properties. This study is on the construction and shape analysis of precise digital data to manage more successfuly using the CRP method and 3D Mono Mobile System. Also this study could acquisite 3D geometrical digital data, make such various space analysis and section, projection, and calculation of bias, area and volume and modeling by rendering technique on the misterious bell of great king of SungDuck, one of the greatest bells in periods of TongIl Silla. So, We suggest utilization of image analysis method to safety diagnosis for the maintenance of cultural properties, archeological and artistic research.

• Geophysics and Geophysical Exploration
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• v.19 no.1
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• pp.11-19
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• 2016

Two representative residual static methods of traveltime decomposition and stack-power maximization are discussed in terms of application to land seismic data. For the model data with synthetic shot/receiver statics (time shift) applied and random noises added, continuities of reflection event are much improved by stack-power maximization method, resulting the derived time-shifts approximately equal to the synthetic statics. Optimal parameters (maximum allowable shift, correlation window, iteration number) for residual statics are effectively chosen with diagnostic displays of CSP (common shot point) stack and CRP (common receiver point) stack as well as CMP gather. In addition to removal of long-wavelength time shift by refraction statics, prior to residual statics, processing steps of f-k filter, predictive deconvolution and time variant spectral whitening are employed to attenuate noises and thereby to minimize the error during the correlation process. The reflectors including horizontal layer of reservoir are more clearly shown in the variable-density section through repicking the velocities after residual statics and inverse NMO correction.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.1
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• pp.69-76
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• 1995

This study is the 3-D precision deformation measurement of a bridge, obtain results of precision control points by GPS and 3-D measurement system and develope efficientlty technices which can solve precision 3-D analysis by CRP In the result, we could overcome the problems of former control point measurement in the way of the combination system of GPS and 3-D measurement system to positioning decision of reference points and control points. Then we could symplify old measurement process on the 3-D deformation analysis of a linear structure and complement parted analysis fault of measurement instrument.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1484-1490
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• 2007

The Cross Reference Point(CRP) is a robust method for finding salient points in watermarking systems because it is based on the geometrical structure of a normalized image in order to avoid pointing error caused by digital attacks. After normalization of an image, the 100 CRPs are calculated. Next, the 100 blocks centered by CRPS are formed. These 100 blocks are arranged using a secrete key. Each boundary of 50 out of 100 blocks is surrounded by 8 blocks which are selected by the ordered number of a preceding block. This number is a seed of random number generator for selecting 8 out of 50 blocks. The search area of a center block is formed by a secrete key. The pixels of a center block are quantized to 10 levels by predefined thresholds. The watermarks are generated by the 50 quantized center blocks. These watermarks are embedded directly in the remaining 50 blocks. In other words, 50 out of 100 blocks are utilized to generate watermarks and the remaining 50 blocks are used to watermark embedding. Because the watermarks are generated in the given images, we can successfully detect watermarks after several digital attacks. The reason is that the blocks for the generation and detection of watermarks are equally affected by digital attacks except for the case of local distortion such as cropping.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.4
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• pp.256-264
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• 2022

Ischemic stroke is caused by an occlusion by a thrombus or embolus in a cerebral artery, preventing oxygenated blood from reaching the brain and causing the necrosis of nerve cells. This paper summarizes the serum candidate markers associated with cardiovascular disease and atrial fibrillation (AF) disease that enable an early diagnosis of ischemic stroke studied thus far and compares the odds ratio (OR) of each marker. This study examined the effect size of these serum candidate markers using meta-analysis techniques. The academic database search screening for articles containing the keywords "cardiovascular disease," "atrial fibrillation," "ischemic stroke," and "serum marker" was limited to results for patients with ischemic stroke. The most derived markers in this study were N-terminal pro-B-type natriuretic peptide (NT-pro-BNP), D-dimer, C-reactive protein (CRP), and glial fibrillary acidic protein (GFAP), the rest being investigated individually. In conclusion, NT-pro-BNP appears to be very useful for the early diagnosis of ischemic stroke. Primarily, it is a marker of AF, and more AF markers will be uncovered and studied in the future.

• Geophysics and Geophysical Exploration
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• v.22 no.4
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• pp.225-238
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• 2019

Migration velocity analysis (MVA) for creating optimum depth-domain velocities in seismic imaging was applied to marine long-offset multi-channel data, and the effectiveness of the MVA approach was demonstrated by the combinations of conventional data processing procedures. The time-domain images generated by conventional time-processing scheme has been considered to be sufficient so far for the seismic stratigraphic interpretation. However, when the purpose of the seismic imaging moves to the hydrocarbon exploration, especially in the geologic modeling of the oil and gas play or lead area, drilling prognosis, in-place hydrocarbon volume estimation, the seismic images should be converted into depth domain or depth processing should be applied in the processing phase. CMP-based velocity analysis, which is mainly based on several approximations in the data domain, inherently contains errors and thus has high uncertainties. On the other hand, the MVA provides efficient and somewhat real-scale (in depth) images even if there are no logging data available. In this study, marine long-offset multi-channel seismic data were optimally processed in time domain to establish the most qualified dataset for the usage of the iterative MVA. Then, the depth-domain velocity profile was updated several times and the final velocity-in-depth was used for generating depth images (CRP gather and stack) and compared with the images obtained from the velocity-in-time. From the results, we were able to confirm the depth-domain results are more reasonable than the time-domain results. The spurious local minima, which can be occurred during the implementation of full waveform inversion, can be reduced when the result of MVA is used as an initial velocity model.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.5
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• pp.492-501
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• 2007

Coastal disasters have become one of the most important issues in every coastal country. In Korea, coastal disasters such as storm surge, sea level rise and extreme weather have placed many coastal regions in danger of being exposed or damaged during subsequent storms and gradual shoreline retreat. A storm surge is an onshore gush of water associated with a tow pressure weather system, typically in typhoon season. However, it is very difficult to predict storm surge height and inundation due to the irregularity of the course and intensity of a typhoon. To provide a new scheme of typhoon damage prediction model, the scenario which changes the central pressure, the maximum wind radius, the track and the proceeding speed by corresponding previous typhoon database, was composed. The virtual typhoon scenario database was constructed with individual scenario simulation and evaluation, in which it extracted the result from the scenario database of information of the hereafter typhoon and information due to climate change. This virtual typhoon scenario database will apply damage prediction information about a typhoon. This study performed construction and analysis of the simulation system with the storm surge/coastal inundation model at Masan coastal areas, and applied method for predicting using the scenario of the storm surge.